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Lv L, Yang C, Zhang X, Chen T, Luo M, Yu G, Chen Q. Autophagy-related protein PlATG2 regulates the vegetative growth, sporangial cleavage, autophagosome formation, and pathogenicity of peronophythora litchii. Virulence 2024; 15:2322183. [PMID: 38438325 PMCID: PMC10913709 DOI: 10.1080/21505594.2024.2322183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 02/18/2024] [Indexed: 03/06/2024] Open
Abstract
Autophagy is an intracellular degradation process that is important for the development and pathogenicity of phytopathogenic fungi and for the defence response of plants. However, the molecular mechanisms underlying autophagy in the pathogenicity of the plant pathogenic oomycete Peronophythora litchii, the causal agent of litchi downy blight, have not been well characterized. In this study, the autophagy-related protein ATG2 homolog, PlATG2, was identified and characterized using a CRISPR/Cas9-mediated gene replacement strategy in P. litchii. A monodansylcadaverine (MDC) staining assay indicated that deletion of PlATG2 abolished autophagosome formation. Infection assays demonstrated that ΔPlatg2 mutants showed significantly impaired pathogenicity in litchi leaves and fruits. Further studies have revealed that PlATG2 participates in radial growth and asexual/sexual development of P. litchii. Moreover, zoospore release and cytoplasmic cleavage of sporangia were considerably lower in the ΔPlatg2 mutants than in the wild-type strain by FM4-64 staining. Taken together, our results revealed that PlATG2 plays a pivotal role in vegetative growth, sporangia and oospore production, zoospore release, sporangial cleavage, and plant infection of P. litchii. This study advances our understanding of the pathogenicity mechanisms of the phytopathogenic oomycete P. litchii and is conducive to the development of effective control strategies.
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Affiliation(s)
- Lin Lv
- Hainan Yazhou Bay Seed Laboratory, College of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Sanya, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou, China
| | - Chengdong Yang
- Hainan Yazhou Bay Seed Laboratory, College of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Sanya, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou, China
| | - Xue Zhang
- Hainan Yazhou Bay Seed Laboratory, College of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Sanya, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou, China
| | - Taixu Chen
- Hainan Yazhou Bay Seed Laboratory, College of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Sanya, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou, China
| | - Manfei Luo
- Hainan Yazhou Bay Seed Laboratory, College of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Sanya, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou, China
| | - Ge Yu
- Hainan Yazhou Bay Seed Laboratory, College of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Sanya, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou, China
| | - Qinghe Chen
- Hainan Yazhou Bay Seed Laboratory, College of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Sanya, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, School of Tropical Agriculture and Forestry, Hainan University, Haikou, China
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Daněk M, Kocourková D, Korec Podmanická T, Eliášová K, Nesvadbová K, Krupař P, Martinec J. A novel workflow for unbiased 3D quantification of autophagosomes in Arabidopsis thaliana roots. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:5412-5427. [PMID: 38430548 DOI: 10.1093/jxb/erae084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/28/2024] [Indexed: 03/04/2024]
Abstract
Macroautophagy is often quantified by live imaging of autophagosomes labeled with fluorescently tagged ATG8 protein (FP-ATG8) in Arabidopsis thaliana. The labeled particles are then counted in single focal planes. This approach may lead to inaccurate results as the actual 3D distribution of autophagosomes is not taken into account and appropriate sampling in the Z-direction is not performed. To overcome this issue, we developed a workflow consisting of immunolabeling of autophagosomes with an anti-ATG8 antibody followed by stereological image analysis using the optical disector and the Cavalieri principle. Our protocol specifically recognized autophagosomes in epidermal cells of Arabidopsis root. Since the anti-ATG8 antibody recognizes multiple AtATG8 isoforms, we were able to detect a higher number of immunolabeled autophagosomes than with the FP-AtATG8e marker, that most probably does not recognize all autophagosomes in a cell. The number of autophagosomes per tissue volume positively correlated with the intensity of autophagy induction. Compared with the quantification of autophagosomes in maximum intensity projections, stereological methods were able to detect the autophagosomes present in a given volume with higher accuracy. Our novel workflow provides a powerful toolkit for unbiased and reproducible quantification of autophagosomes and offers a convenient alternative to the standard of live imaging with FP-ATG8 markers.
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Affiliation(s)
- Michal Daněk
- Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 00 Prague, Czech Republic
| | - Daniela Kocourková
- Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 00 Prague, Czech Republic
| | - Tereza Korec Podmanická
- Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 00 Prague, Czech Republic
| | - Kateřina Eliášová
- Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 00 Prague, Czech Republic
| | - Kristýna Nesvadbová
- Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 00 Prague, Czech Republic
| | - Pavel Krupař
- Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 00 Prague, Czech Republic
| | - Jan Martinec
- Czech Academy of Sciences, Institute of Experimental Botany, Rozvojová 263, 165 00 Prague, Czech Republic
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Jiang D, He Y, Li H, Dai L, Sun B, Yang L, Pang L, Cao Z, Liu Y, Gao J, Zhang Y, Jiang L, Li R. A condensates-to-VPS41-associated phagic vacuoles conversion pathway controls autophagy degradation in plants. Dev Cell 2024; 59:2287-2301.e6. [PMID: 39111309 DOI: 10.1016/j.devcel.2024.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 05/15/2024] [Accepted: 07/11/2024] [Indexed: 09/12/2024]
Abstract
Autophagy is a universal degradation system in eukaryotic cells. In plants, although autophagosome biogenesis has been extensively studied, the mechanism of how autophagosomes are transported to the vacuole for degradation remains largely unexplored. In this study, we demonstrated that upon autophagy induction, Arabidopsis homotypic fusion and protein sorting (HOPS) subunit VPS41 converts first from condensates to puncta, then to ring-like structures, termed VPS41-associated phagic vacuoles (VAPVs), which enclose autophagy-related gene (ATG)8s for vacuolar degradation. This process is initiated by ADP ribosylation factor (ARF)-like GTPases ARLA1s and occurs concurrently with autophagy progression through coupling with the synaptic-soluble N-ethylmaleimide-sensitive factor attachment protein rmleceptor (SNARE) proteins. Unlike in other eukaryotes, autophagy degradation in Arabidopsis is largely independent of the RAB7 pathway. By contrast, dysfunction in the condensates-to-VAPVs conversion process impairs autophagosome structure and disrupts their vacuolar transport, leading to a significant reduction in autophagic flux and plant survival rate. Our findings suggest that the conversion pathway might be an integral part of the autophagy program unique to plants.
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Affiliation(s)
- Dong Jiang
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yilin He
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hailin Li
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Liufeng Dai
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Science, Beijing Normal University, Beijing 100875, China; Center for Biological Science and Technology, Zhuhai-Macao Biotechnology Joint Laboratory, Advanced Institute of Natural Science, Beijing Normal University, Zhuhai 519087, China
| | - Bingyan Sun
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lianming Yang
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lei Pang
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhiran Cao
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yu Liu
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jiayang Gao
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yi Zhang
- Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Science, Beijing Normal University, Beijing 100875, China; Center for Biological Science and Technology, Zhuhai-Macao Biotechnology Joint Laboratory, Advanced Institute of Natural Science, Beijing Normal University, Zhuhai 519087, China
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China; Institute of Plant Molecular Biology and Agricultural Biotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China; CUHK Shenzhen Research Institute, Shenzhen 518057, China
| | - Ruixi Li
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.
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Zhuang X, Li B, Jiang L. Autophagosome biogenesis and organelle homeostasis in plant cells. THE PLANT CELL 2024; 36:3009-3024. [PMID: 38536783 PMCID: PMC11371174 DOI: 10.1093/plcell/koae099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/23/2024] [Indexed: 09/05/2024]
Abstract
Autophagy is one of the major highly inducible degradation processes in response to plant developmental and environmental signals. In response to different stimuli, cellular materials, including proteins and organelles, can be sequestered into a double membrane autophagosome structure either selectively or nonselectively. The formation of an autophagosome as well as its delivery into the vacuole involves complex and dynamic membrane processes. The identification and characterization of the conserved autophagy-related (ATG) proteins and their related regulators have greatly advanced our understanding of the molecular mechanism underlying autophagosome biogenesis and function in plant cells. Autophagosome biogenesis is tightly regulated by the coordination of multiple ATG and non-ATG proteins and by selective cargo recruitment. This review updates our current knowledge of autophagosome biogenesis, with special emphasis on the core molecular machinery that drives autophagosome formation and autophagosome-organelle interactions under abiotic stress conditions.
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Affiliation(s)
- Xiaohong Zhuang
- School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Baiying Li
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Institute of Plant Molecular Biology and Agricultural Biotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong, China
- CUHK Shenzhen Research Institute, Shenzhen 518057, China
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5
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Lu J, Li N, Li G, Tian Z, Shi L, Wang Y, Cai Y, Zhang K, Sun W, Wang D, Lin J, Huang J, Wu C, Yan K, Zhang S, Zheng C, Yang G. N-glycosylation of SnRK2s affects NADPH maintenance in peroxisomes during prolonged ABA signalling. Nat Commun 2024; 15:6630. [PMID: 39103337 DOI: 10.1038/s41467-024-50720-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 07/19/2024] [Indexed: 08/07/2024] Open
Abstract
Unfavourable conditions, such as prolonged drought and high salinity, pose a threat to the survival and agricultural yield of plants. The phytohormone ABA plays a key role in the regulation of plant stress adaptation and is often maintained at high levels for extended periods. While much is known about ABA signal perception and activation in the early signalling stage, the molecular mechanism underlying desensitization of ABA signalling remains largely unknown. Here we demonstrate that in the endoplasmic reticulum (ER)-Golgi network, the key regulators of ABA signalling, SnRK2.2/2.3, undergo N-glycosylation, which promotes their redistribution from the nucleus to the peroxisomes in Arabidopsis roots and influences the transcriptional response in the nucleus during prolonged ABA signalling. On the peroxisomal membrane, SnRK2s can interact with glucose-6-phosphate (G6P)/phosphate translocator 1 (GPT1) to maintain NADPH homeostasis through increased activity of the peroxisomal oxidative pentose phosphate pathway (OPPP). The resulting maintenance of NADPH is essential for the modulation of hydrogen peroxide (H2O2) accumulation, thereby relieving ABA-induced root growth inhibition. The subcellular dynamics of SnRK2s, mediated by N-glycosylation suggest that ABA responses transition from transcriptional regulation in the nucleus to metabolic processes in the peroxisomes, aiding plants in adapting to long-term environmental stress.
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Affiliation(s)
- Junyao Lu
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Ning Li
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Gaojian Li
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Ziang Tian
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Lianping Shi
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Yan Wang
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Yingao Cai
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Kaiyuan Zhang
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Wanting Sun
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Danyang Wang
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Jinxin Lin
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Jinguang Huang
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Changai Wu
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Kang Yan
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Shizhong Zhang
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China
| | - Chengchao Zheng
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China.
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China.
| | - Guodong Yang
- College of Life Sciences, Shandong Agricultural University, Taian, Shandong, PR China.
- National Key Laboratory of Wheat Improvement, Shandong Agricultural University, Taian, Shandong, PR China.
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Wang Y, Jiang Y, Liu X, Chen Y, Zhang Q, Wang L, Li W. Analysis of Ginkgo biloba Root Exudates and Inhibition of Soil Fungi by Flavonoids and Terpene Lactones. PLANTS (BASEL, SWITZERLAND) 2024; 13:2122. [PMID: 39124240 PMCID: PMC11314191 DOI: 10.3390/plants13152122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 07/29/2024] [Accepted: 07/29/2024] [Indexed: 08/12/2024]
Abstract
Ginkgo biloba is abundant in secondary metabolites, including flavonoids and terpenoids. While the majority of research has focused on the role of these compounds in disease resistance, their specific contribution to pathogen defense has been rarely explored. In this study, we collected root exudates from hydroponically cultivated ginkgo seedlings and conducted a metabolomic analysis. We identified several primary metabolites mainly comprising amino acids and nucleotides, while secondary metabolites consisted of various compounds, including bioactive compounds such as flavonoids and terpenoids. Focusing on the secondary metabolites with relatively higher abundance in the exudates, we selected a mixture of flavonoids and terpenoids for in vitro inhibition experiments against two soil-borne fungal pathogens, Fusarium oxysporum f. sp. cucumerinum that causes cucumber wilt and Rhizoctonia solani AG-8 that causes wheat root rot. The results indicated that the growth rate of both fungus cells was significantly reduced with the increasing concentration of the flavonoid and terpenoid mixture extracted from ginkgo and was completely inhibited at a concentration of 5 mg/mL. Further experiments revealed that this mixture of flavonoids and terpenoids had a destructive effect on the cellular structure of both fungi, thereby reducing cell viability and achieving an antifungal effect. These findings provide a foundation for further research into the use of ginkgo extracts in biological control.
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Affiliation(s)
- Yawen Wang
- College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou 225000, China; (Y.W.); (Y.J.); (X.L.); (Y.C.); (L.W.)
| | - Yanbing Jiang
- College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou 225000, China; (Y.W.); (Y.J.); (X.L.); (Y.C.); (L.W.)
| | - Ximeng Liu
- College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou 225000, China; (Y.W.); (Y.J.); (X.L.); (Y.C.); (L.W.)
| | - Yadi Chen
- College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou 225000, China; (Y.W.); (Y.J.); (X.L.); (Y.C.); (L.W.)
| | - Qingxia Zhang
- College of Plant Protection, Yangzhou University, Yangzhou 225000, China;
| | - Li Wang
- College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou 225000, China; (Y.W.); (Y.J.); (X.L.); (Y.C.); (L.W.)
| | - Weixing Li
- College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou 225000, China; (Y.W.); (Y.J.); (X.L.); (Y.C.); (L.W.)
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Wang J, Li Y, Niu Y, Liu Y, Zhang Q, Lv Y, Li S, Wang X, Bao Y. Characterization of tomato autophagy-related SlCOST family genes. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 342:112032. [PMID: 38354756 DOI: 10.1016/j.plantsci.2024.112032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 01/12/2024] [Accepted: 02/09/2024] [Indexed: 02/16/2024]
Abstract
Autophagy is a eukaryote-specific cellular process that can engulf unwanted targets with double-membrane autophagosomes and subject them to the vacuole or lysosome for breaking down and recycling, playing dual roles in plant growth and environmental adaptions. However, perception of specific environmental signals for autophagy induction is largely unknown, limiting its application in agricultural usage. Identification of plant-unique DUF641 family COST1 (Constitutively Stressed 1) protein directly links drought perception and autophagy induction, shedding light on manipulating autophagy for breeding stress tolerant crops. In this study, we performed a genome-wide analysis of DUF641/COST family in tomato, and identified five SlCOST genes SlCOST1, -2, -3, -4, and -5. SlCOST genes show both overlapping and distinct expression patterns in plant growth and stress responding. In addition, SlCOST1, -3, -4, -5 proteins demonstrate co-localization with autophagy adaptor protein ATG8e, and all five SlCOST proteins show interactions ATG8e in planta. However, only SlCOST1, the closest ortholog of Arabidopsis AtCOST1, can restore cost1 mutant to WT level, suggesting conserved role of COST1 and functional diversification of SlCOST family in tomato. Our study provides clues for future investigation of autophagy-related COST family and its promising implementations in breeding crops with robust environmental plasticity.
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Affiliation(s)
- Jiaojiao Wang
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yanjie Li
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yue Niu
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yao Liu
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qian Zhang
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yonglun Lv
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shuxia Li
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
| | - Xinhua Wang
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yan Bao
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
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Zhuang X, Li R, Jiang L. A century journey of organelles research in the plant endomembrane system. THE PLANT CELL 2024; 36:1312-1333. [PMID: 38226685 PMCID: PMC11062446 DOI: 10.1093/plcell/koae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 11/14/2023] [Accepted: 01/09/2024] [Indexed: 01/17/2024]
Abstract
We are entering an exciting century in the study of the plant organelles in the endomembrane system. Over the past century, especially within the past 50 years, tremendous advancements have been made in the complex plant cell to generate a much clearer and informative picture of plant organelles, including the molecular/morphological features, dynamic/spatial behavior, and physiological functions. Importantly, all these discoveries and achievements in the identification and characterization of organelles in the endomembrane system would not have been possible without: (1) the innovations and timely applications of various state-of-art cell biology tools and technologies for organelle biology research; (2) the continuous efforts in developing and characterizing new organelle markers by the plant biology community; and (3) the landmark studies on the identification and characterization of the elusive organelles. While molecular aspects and results for individual organelles have been extensively reviewed, the development of the techniques for organelle research in plant cell biology is less appreciated. As one of the ASPB Centennial Reviews on "organelle biology," here we aim to take a journey across a century of organelle biology research in plants by highlighting the important tools (or landmark technologies) and key scientists that contributed to visualize organelles. We then highlight the landmark studies leading to the identification and characterization of individual organelles in the plant endomembrane systems.
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Affiliation(s)
- Xiaohong Zhuang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Ruixi Li
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Institute of Plant Molecular Biology and Agricultural Biotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong, China
- CUHK Shenzhen Research Institute, Shenzhen 518057, China
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Lu Z, Zhang J, Wang H, Zhang K, Gu Z, Xu Y, Zhang J, Wang M, Han L, Xiang F, Zhou C. Rewiring of a KNOXI regulatory network mediated by UFO underlies the compound leaf development in Medicago truncatula. Nat Commun 2024; 15:2988. [PMID: 38582884 PMCID: PMC10998843 DOI: 10.1038/s41467-024-47362-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 03/28/2024] [Indexed: 04/08/2024] Open
Abstract
Class I KNOTTED-like homeobox (KNOXI) genes are parts of the regulatory network that control the evolutionary diversification of leaf morphology. Their specific spatiotemporal expression patterns in developing leaves correlate with the degrees of leaf complexity between simple-leafed and compound-leafed species. However, KNOXI genes are not involved in compound leaf formation in several legume species. Here, we identify a pathway for dual repression of MtKNOXI function in Medicago truncatula. PINNATE-LIKE PENTAFOLIATA1 (PINNA1) represses the expression of MtKNOXI, while PINNA1 interacts with MtKNOXI and sequesters it to the cytoplasm. Further investigations reveal that UNUSUAL FLORAL ORGANS (MtUFO) is the direct target of MtKNOXI, and mediates the transition from trifoliate to pinnate-like pentafoliate leaves. These data suggest a new layer of regulation for morphological diversity in compound-leafed species, in which the conserved regulators of floral development, MtUFO, and leaf development, MtKNOXI, are involved in variation of pinnate-like compound leaves in M. truncatula.
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Affiliation(s)
- Zhichao Lu
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Juanjuan Zhang
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Hongfeng Wang
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
- Shandong Peanut Research Institute, Qingdao, 266199, China
| | - Ke Zhang
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Zhiqun Gu
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Yiteng Xu
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Jing Zhang
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Min Wang
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Lu Han
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Fengning Xiang
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Chuanen Zhou
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China.
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10
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Huang X, Wang J, Chen S, Liu S, Li Z, Wang Z, Chen B, Zhang C, Zhang Y, Wu J, Yang X, Xie Q, Li F, An H, Huang J, Li H, Liu C, Wu X, Liu DX, Yang X, Zhou G, Zhang T. Rhabdovirus encoded glycoprotein induces and harnesses host antiviral autophagy for maintaining its compatible infection. Autophagy 2024; 20:275-294. [PMID: 37656054 PMCID: PMC10813567 DOI: 10.1080/15548627.2023.2252273] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 09/02/2023] Open
Abstract
Macroautophagy/autophagy has been recognized as a central antiviral defense mechanism in plant, which involves complex interactions between viral proteins and host factors. Rhabdoviruses are single-stranded RNA viruses, and the infection causes serious harm to public health, livestock, and crop production. However, little is known about the role of autophagy in the defense against rhabdovirus infection by plant. In this work, we showed that Rice stripe mosaic cytorhabdovirus(RSMV) activated autophagy in plants and that autophagy served as an indispensable defense mechanism during RSMV infection. We identified RSMV glycoprotein as an autophagy inducer that interacted with OsSnRK1B and promoted the kinase activity of OsSnRK1B on OsATG6b. RSMV glycoprotein was toxic to rice cells and its targeted degradation by OsATG6b-mediated autophagy was essential to restrict the viral titer in plants. Importantly, SnRK1-glycoprotein and ATG6-glycoprotein interactions were well-conserved between several other rhabdoviruses and plants. Together, our data support a model that SnRK1 senses rhabdovirus glycoprotein for autophagy initiation, while ATG6 mediates targeted degradation of viral glycoprotein. This conserved mechanism ensures compatible infection by limiting the toxicity of viral glycoprotein and restricting the infection of rhabdoviruses.Abbreviations: AMPK: adenosine 5'-monophosphate (AMP)-activated protein kinase; ANOVA: analysis of variance; ATG: autophagy related; AZD: AZD8055; BiFC: bimolecular fluorescence complementation; BYSMV: barley yellow striate mosaic virus; Co-IP: co-immunoprecipitation; ConA: concanamycin A; CTD: C-terminal domain; DEX: dexamethasone; DMSO: dimethyl sulfoxide; G: glycoprotein; GFP: green fluorescent protein; MD: middle domain; MDC: monodansylcadaverine; NTD: N-terminal domain; OE: over expression; Os: Oryza sativa; PBS: phosphate-buffered saline; PtdIns3K: class III phosphatidylinositol-3-kinase; qRT-PCR: quantitative real-time reverse-transcription PCR; RFP: red fluorescent protein; RSMV: rice stripe mosaic virus; RSV: rice stripe virus; SGS3: suppressor of gene silencing 3; SnRK1: sucrose nonfermenting1-related protein kinase1; SYNV: sonchus yellow net virus; TEM: transmission electron microscopy; TM: transmembrane region; TOR: target of rapamycin; TRV: tobacco rattle virus; TYMaV: tomato yellow mottle-associated virus; VSV: vesicular stomatitis virus; WT: wild type; Y2H: yeast two-hybrid; YFP: yellow fluorescent protein.
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Affiliation(s)
- Xiuqin Huang
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Junkai Wang
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Siping Chen
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Siying Liu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Zhanbiao Li
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Zhiyi Wang
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Biao Chen
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Chong Zhang
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Yifei Zhang
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Jinhui Wu
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Xiaorong Yang
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Qingjun Xie
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, Guangdong, China
| | - Faqiang Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China
| | - Hong An
- Bioinformatics and Analytics Core, University of Missouri, Columbia, MO, USA
| | - Jilei Huang
- Instrumental Analysis and Research Center, South China Agricultural University, Guangzhou, Guangdong, China
| | - Huali Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, Guangdong, China
| | - Chuanhe Liu
- Instrumental Analysis and Research Center, South China Agricultural University, Guangzhou, Guangdong, China
| | - Xiaoxian Wu
- Instrumental Analysis and Research Center, South China Agricultural University, Guangzhou, Guangdong, China
| | - Ding Xiang Liu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Xin Yang
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Guohui Zhou
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Tong Zhang
- National Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
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11
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Huang L, Wen X, Jin L, Han H, Guo H. HOOKLESS1 acetylates AUTOPHAGY-RELATED PROTEIN18a to promote autophagy during nutrient starvation in Arabidopsis. THE PLANT CELL 2023; 36:136-157. [PMID: 37823521 PMCID: PMC10734606 DOI: 10.1093/plcell/koad252] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/23/2023] [Accepted: 09/14/2023] [Indexed: 10/13/2023]
Abstract
Acetylation is an important posttranslational modification (PTM) that regulates almost all core processes of autophagy in yeast and mammals. However, the role of protein acetylation in plant autophagy and the underlying regulatory mechanisms remain unclear. Here, we show the essential role of the putative acetyltransferase HOOKLESS1 (HLS1) in acetylation of the autophagy-related protein ATG18a, a key autophagy component that regulates autophagosome formation in Arabidopsis (Arabidopsis thaliana). Loss of HLS1 function suppressed starvation-induced autophagy and increased plant susceptibility to nutrient deprivation. We discovered that HLS1 physically interacts with and directly acetylates ATG18a both in vitro and in vivo. In contrast, mutating putative active sites in HLS1 inhibited ATG18a acetylation and suppressed autophagy upon nutrient deprivation. Accordingly, overexpression of ATG18a mutant variants with lower acetylation levels inhibited the binding activity of ATG18a to PtdIns(3)P and autophagosome formation under starvation conditions. Moreover, HLS1-modulated autophagy was uncoupled from its function in hook development. Taken together, these findings shed light on a key regulator of autophagy and further elucidate the importance of PTMs in modulating autophagy in plants.
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Affiliation(s)
- Li Huang
- New Cornerstone Science Laboratory, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055, China
| | - Xing Wen
- New Cornerstone Science Laboratory, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055, China
| | - Lian Jin
- New Cornerstone Science Laboratory, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055, China
| | - Huihui Han
- New Cornerstone Science Laboratory, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055, China
| | - Hongwei Guo
- New Cornerstone Science Laboratory, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055, China
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12
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Liu Z, Yang Q, Wu P, Li Y, Lin Y, Liu W, Guo S, Liu Y, Huang Y, Xu P, Qian Y, Xie Q. Dynamic monitoring of TGW6 by selective autophagy during grain development in rice. THE NEW PHYTOLOGIST 2023; 240:2419-2435. [PMID: 37743547 DOI: 10.1111/nph.19271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 08/31/2023] [Indexed: 09/26/2023]
Abstract
Crop yield must increase to achieve food security in the face of a growing population and environmental deterioration. Grain size is a prime breeding target for improving grain yield and quality in crop. Here, we report that autophagy emerges as an important regulatory pathway contributing to grain size and quality in rice. Mutations of rice Autophagy-related 9b (OsATG9b) or OsATG13a causes smaller grains and increase of chalkiness, whereas overexpression of either promotes grain size and quality. We also demonstrate that THOUSAND-GRAIN WEIGHT 6 (TGW6), a superior allele that regulates grain size and quality in the rice variety Kasalath, interacts with OsATG8 via the canonical Atg8-interacting motif (AIM), and then is recruited to the autophagosome for selective degradation. In consistent, alteration of either OsATG9b or OsATG13a expression results in reciprocal modulation of TGW6 abundance during grain growth. Genetic analyses confirmed that knockout of TGW6 in either osatg9b or osatg13a mutants can partially rescue their grain size defects, indicating that TGW6 is one of the substrates for autophagy to regulate grain development. We therefore propose a potential framework for autophagy in contributing to grain size and quality in crops.
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Affiliation(s)
- Zinan Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Qianying Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Pingfan Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Yifan Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Yanni Lin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Wanqing Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Academy of Agricultural Sciences, Rice Research Institute, Guangzhou, 510640, China
| | - Shaoying Guo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Yunfeng Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences and Technology, Guangxi University, Nanning, 530004, China
| | - Yifeng Huang
- Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Science, Hangzhou, 310001, China
| | - Peng Xu
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, The Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, 666303, China
| | - Yangwen Qian
- WIMI Biotechnology Co. Ltd., Changzhou, 213000, China
| | - Qingjun Xie
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
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13
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Yang J, Qiu L, Mei Q, Sun Y, Li N, Gong X, Ma F, Mao K. MdHB7-like positively modulates apple salt tolerance by promoting autophagic activity and Na + efflux. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:669-689. [PMID: 37471682 DOI: 10.1111/tpj.16395] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/26/2023] [Accepted: 07/10/2023] [Indexed: 07/22/2023]
Abstract
Salt stress adversely affects the yield and quality of crops and limits their geographical distribution. Studying the functions and regulatory mechanisms of key genes in the salt stress response is important for breeding crops with enhanced stress resistance. Autophagy plays an important role in modulating the tolerance of plants to various types of abiotic stressors. However, the mechanisms underlying salt-induced autophagy are largely unknown. Cation/Ca2+ exchanger proteins enhance apple salt tolerance by inhibiting Na+ accumulation but the mechanism underlying the response to salt stress remains unclear. Here, we show that the autophagy-related gene MdATG18a modulated apple salt tolerance. Under salt stress, the autophagic activity, proline content, and antioxidant enzyme activities were higher and Na+ accumulation was lower in MdATG18a-overexpressing transgenic plants than in control plants. The use of an autophagy inhibitor during the salt treatment demonstrated that the regulatory function of MdATG18a depended on autophagy. The yeast-one-hybrid assay revealed that the homeodomain-leucine zipper (HD-Zip) transcription factor MdHB7-like directly bound to the MdATG18a promoter. Transcriptional regulation and genetic analyses showed that MdHB7-like enhanced salt-induced autophagic activity by promoting MdATG18a expression. The analysis of Na+ efflux rate in transgenic yeast indicated that MdCCX1 expression significantly promoted Na+ efflux. Promoter binding, transcriptional regulation, and genetic analyses showed that MdHB7-like promoted Na+ efflux and apple salt tolerance by directly promoting MdCCX1 expression, which was independent of the autophagy pathway. Overall, our findings provide insight into the mechanism underlying MdHB7-like-mediated salt tolerance in apple through the MdHB7-like-MdATG18a and MdHB7-like-MdCCX1 modules. These results will aid future studies on the mechanisms underlying stress-induced autophagy and the regulation of stress tolerance in plants.
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Affiliation(s)
- Jie Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Lina Qiu
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Quanlin Mei
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yunxia Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Na Li
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xiaoqing Gong
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Fengwang Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Ke Mao
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
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14
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Liao CY, Pu Y, Nolan TM, Montes C, Guo H, Walley JW, Yin Y, Bassham DC. Brassinosteroids modulate autophagy through phosphorylation of RAPTOR1B by the GSK3-like kinase BIN2 in Arabidopsis. Autophagy 2023; 19:1293-1310. [PMID: 36151786 PMCID: PMC10012961 DOI: 10.1080/15548627.2022.2124501] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Macroautophagy/autophagy is a conserved recycling process that maintains cellular homeostasis during environmental stress. Autophagy is negatively regulated by TOR (target of rapamycin), a nutrient-regulated protein kinase that in plants is activated by several phytohormones, leading to increased growth. However, the detailed molecular mechanisms by which TOR integrates autophagy and hormone signaling are poorly understood. Here, we show that TOR modulates brassinosteroid (BR)-regulated plant growth and stress-response pathways. Active TOR was required for full BR-mediated growth in Arabidopsis thaliana. Autophagy was constitutively up-regulated upon blocking BR biosynthesis or signaling, and down-regulated by increasing the activity of the BR pathway. BIN2 (brassinosteroid-insensitive 2) kinase, a GSK3-like kinase functioning as a negative regulator in BR signaling, directly phosphorylated RAPTOR1B (regulatory-associated protein of TOR 1B), a substrate-recruiting subunit in the TOR complex, at a conserved serine residue within a typical BIN2 phosphorylation motif. Mutation of RAPTOR1B serine 916 to alanine, to block phosphorylation by BIN2, repressed autophagy and increased phosphorylation of the TOR substrate ATG13a (autophagy-related protein 13a). By contrast, this mutation had only a limited effect on growth. We present a model in which RAPTOR1B is phosphorylated and inhibited by BIN2 when BRs are absent, activating the autophagy pathway. When BRs signal and inhibit BIN2, RAPTOR1B is thus less inhibited by BIN2 phosphorylation. This leads to increased TOR activity and ATG13a phosphorylation, and decreased autophagy activity. Our studies define a new mechanism by which coordination between BR and TOR signaling pathways helps to maintain the balance between plant growth and stress responses.
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Affiliation(s)
- Ching-Yi Liao
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Yunting Pu
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Trevor M Nolan
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Christian Montes
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, USA
| | - Hongqing Guo
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Justin W Walley
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, USA
| | - Yanhai Yin
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
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15
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Wu Z, Wu QF, Yuan WL, Chen YH, Hu D, Deng DY, Zhang LL, Niu XM. Arthrocolins Synergizing with Fluconazole Inhibit Fluconazole-Resistant Candida albicans by Increasing Riboflavin Metabolism and Causing Mitochondrial Dysfunction and Autophagy. Microbiol Spectr 2023; 11:e0405122. [PMID: 36847492 PMCID: PMC10101122 DOI: 10.1128/spectrum.04051-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 02/03/2023] [Indexed: 03/01/2023] Open
Abstract
Our previous study reported that seminaturally occurring arthrocolins A to C with unprecedented carbon skeletons could restore the antifungal activity of fluconazole against fluconazole-resistant Candida albicans. Here, we showed that arthrocolins synergized with fluconazole, reducing the fluconazole minimum and dramatically augmenting the survivals of 293T human cells and nematode Caenorhabditis elegans infected with fluconazole-resistant C. albicans. Mechanistically, fluconazole can induce fungal membrane permeability to arthrocolins, leading to the intracellular arthrocolins that were critical to the antifungal activity of the combination therapy by inducing abnormal cell membranes and mitochondrial dysfunctions in the fungus. Transcriptomics and reverse transcription-quantitative PCR (qRT-PCR) analysis indicated that the intracellular arthrocolins induced the strongest upregulated genes that were involved in membrane transports while the downregulated genes were responsible for fungal pathogenesis. Moreover, riboflavin metabolism and proteasomes were the most upregulated pathways, which were accompanied by inhibition of protein biosynthesis and increased levels of reactive oxygen species (ROS), lipids, and autophagy. Our results suggested that arthrocolins should be a novel class of synergistic antifungal compounds by inducing mitochondrial dysfunctions in combination with fluconazole and provided a new perspective for the design of new bioactive antifungal compounds with potential pharmacological properties. IMPORTANCE The prevalence of antifungal-resistant Candida albicans, which is a common human fungal pathogen causing life-threatening systemic infections, has become a challenge in the treatment of fungal infections. Arthrocolins are a new type of xanthene obtained from Escherichia coli fed with a key fungal precursor toluquinol. Different from those artificially synthesized xanthenes used as important medications, arthrocolins can synergize with fluconazole against fluconazole-resistant Candida albicans. Fluconazole can induce the fungal permeability of arthrocolins into fungal cells, and then the intracellular arthrocolins exerted detrimental effects on the fungus by inducing fungal mitochondrial dysfunctions, leading to dramatically reduced fungal pathogenicity. Importantly, the combination of arthrocolins and fluconazole are effective against C. albicans in two models, including human cell line 293T and nematode Caenorhabditis elegans. Arthrocolins should be a novel class of antifungal compounds with potential pharmacological properties.
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Affiliation(s)
- Zhuang Wu
- Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
| | - Qun-Fu Wu
- Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
| | - Wen-Li Yuan
- Department of Clinical Laboratory, The Affiliated Hospital of Yunnan University, The second hospital of Yunnan Province, Kunming, Yunnan Province, People’s Republic of China
| | - Yong-Hong Chen
- Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
| | - Di Hu
- Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
| | - De-Yao Deng
- Department of Clinical Laboratory, The Affiliated Hospital of Yunnan University, The second hospital of Yunnan Province, Kunming, Yunnan Province, People’s Republic of China
| | - Long-Long Zhang
- Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
| | - Xue-Mei Niu
- Laboratory for Conservation and Utilization of Bio-Resources, Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, People’s Republic of China
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16
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Ding G, Mugume Y, Dueñas ME, Lee YJ, Liu M, Nettleton DS, Zhao X, Li L, Bassham DC, Nikolau BJ. Biological insights from multi-omics analysis strategies: Complex pleotropic effects associated with autophagy. FRONTIERS IN PLANT SCIENCE 2023; 14:1093358. [PMID: 36875559 PMCID: PMC9978356 DOI: 10.3389/fpls.2023.1093358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
Research strategies that combine molecular data from multiple levels of genome expression (i.e., multi-omics data), often referred to as a systems biology strategy, has been advocated as a route to discovering gene functions. In this study we conducted an evaluation of this strategy by combining lipidomics, metabolite mass-spectral imaging and transcriptomics data from leaves and roots in response to mutations in two AuTophaGy-related (ATG) genes of Arabidopsis. Autophagy is an essential cellular process that degrades and recycles macromolecules and organelles, and this process is blocked in the atg7 and atg9 mutants that were the focus of this study. Specifically, we quantified abundances of ~100 lipids and imaged the cellular locations of ~15 lipid molecular species and the relative abundance of ~26,000 transcripts from leaf and root tissues of WT, atg7 and atg9 mutant plants, grown either in normal (nitrogen-replete) and autophagy-inducing conditions (nitrogen-deficient). The multi-omics data enabled detailed molecular depiction of the effect of each mutation, and a comprehensive physiological model to explain the consequence of these genetic and environmental changes in autophagy is greatly facilitated by the a priori knowledge of the exact biochemical function of the ATG7 and ATG9 proteins.
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Affiliation(s)
- Geng Ding
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Yosia Mugume
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
| | | | - Young Jin Lee
- Department of Chemistry, Iowa State University, Ames, IA, United States
| | - Meiling Liu
- Department of Statistics, Iowa State University, Ames, IA, United States
| | | | - Xuefeng Zhao
- Research Information Technology, College of Liberal Arts & Sciences, Iowa State University, Ames, IA, United States
| | - Ling Li
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, United States
| | - Diane C. Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
| | - Basil J. Nikolau
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
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17
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Arcalís E, Hörmann-Dietrich U, Stöger E. Multiscale imaging reveals the presence of autophagic vacuoles in developing maize endosperm. FRONTIERS IN PLANT SCIENCE 2023; 13:1082890. [PMID: 36684761 PMCID: PMC9853038 DOI: 10.3389/fpls.2022.1082890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
Cereal endosperm is solely devoted to the storage of proteins and starch that will be used by the embryo upon germination. The high degree of specialization of this tissue is reflected in its endomembrane system, in which ER derived protein bodies and protein storage vacuoles (PSVs) are of particular interest. In maize seeds, the main storage proteins are zeins, that form transport incompetent aggregates within the ER lumen and finally build protein bodies that bud from the ER. In contrast to the zeins, the maize globulins are not very abundant and the vacuolar storage compartment of maize endosperm is not fully described. Whereas in other cereals, including wheat and barley, the PSV serves as the main protein storage compartment, only small, globulin-containing PSVs have been identified in maize so far. We present here a multi-scale set of data, ranging from live-cell imaging to more sophisticated 3D electron microscopy techniques (SBF-SEM), that has allowed us to investigate in detail the vacuoles in maize endosperm cells, including a novel, autophagic vacuole that is present in early developmental stages.
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18
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Pu Y, Bassham DC. Detection of Autophagy in Plants by Fluorescence Microscopy. Methods Mol Biol 2023; 2581:135-147. [PMID: 36413316 DOI: 10.1007/978-1-0716-2784-6_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Autophagy is a key process for degradation and recycling of proteins or organelles in eukaryotes. Autophagy in plants has been shown to function in stress responses, pathogen immunity, and senescence, while a basal level of autophagy plays a housekeeping role in cells. Upon activation of autophagy, vesicles termed autophagosomes are formed to deliver proteins or organelles to the vacuole for degradation. The number of autophagosomes can thus be used to indicate the level of autophagy. Here we describe two common methods used for detection of autophagosomes, staining of autophagosomes with the fluorescent dye monodansylcadaverine and expression of a fusion between GFP and the autophagosomal membrane protein ATG8.
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Affiliation(s)
- Yunting Pu
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA.
- Plant Sciences Institute, Iowa State University, Ames, IA, USA.
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19
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Guan B, Jiang YT, Lin DL, Lin WH, Xue HW. Phosphatidic acid suppresses autophagy through competitive inhibition by binding GAPC (glyceraldehyde-3-phosphate dehydrogenase) and PGK (phosphoglycerate kinase) proteins. Autophagy 2022; 18:2656-2670. [PMID: 35289711 PMCID: PMC9629070 DOI: 10.1080/15548627.2022.2046449] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Macroautophagy/autophagy is a finely-regulated process in which cytoplasm encapsulated within transient organelles termed autophagosomes is delivered to lysosomes or vacuoles for degradation. Phospholipids, particularly phosphatidic acid (PA) that functions as a second messenger, play crucial and differential roles in autophagosome formation; however, the underlying mechanism remains largely unknown. Here we demonstrated that PA inhibits autophagy through competitive inhibition of the formation of ATG3 (autophagy-related)-ATG8e and ATG6-VPS34 (vacuolar protein sorting 34) complexes. PA bound to GAPC (glyceraldehyde-3-phosphate dehydrogenase) or PGK (phosphoglycerate kinase) and promoted their interaction with ATG3 or ATG6, which further attenuated the interactions of ATG3-ATG8e or ATG6-VPS34, respectively. Structural and mutational analyses revealed the mechanism of PA binding with GAPCs and PGK3, and that GAPCs or ATG8e competitively interacted with ATG3, and PGK3 or VPS34 competitively interacted with ATG6, at the same binding interface. These results elucidate the molecular mechanism of how PA inhibits autophagy through binding GAPC or PGK3 proteins and expand the understanding of the functional mode of PA, demonstrating the importance of phospholipids in plant autophagy and providing a new perspective for autophagy regulation by phospholipids.Abbreviation: ATG: autophagy-related; BiFC: bimolecular fluorescence complementation; co-IP: co-immunoprecipitation; Con A: concanamycin A; ER: endoplasmic reticulum; EZ: elongation zone; FRET-FLIM: fluorescence resonance energy transfer with fluorescence lifetime imaging microscopy; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GST: glutathione S-transferase; MDC: monodansylcadaverine; MZ: meristem zone; PA: phosphatidic acid; PAS: phagophore assembly site; PC: phosphatidylcholine; PE: phosphatidylethanolamine; PGK3: phosphoglycerate kinase; PtdIns3K: phosphatidylinositol 3-kinase; PLD: phospholipase D; TEM: transmission electron microscopy; TOR: target of rapamycin; VPS34: vacuolar protein sorting 34; WT: wild type; Y2H: yeast two-hybrid.
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Affiliation(s)
- Bin Guan
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, Minhang, China,National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, Xuhui, China
| | - Yu-Tong Jiang
- School of Life Sciences and Biotechnology, The Joint International Research Laboratory of Metabolic and Developmental Sciences, Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai, Minhang, China
| | - De-Li Lin
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, Minhang, China
| | - Wen-Hui Lin
- School of Life Sciences and Biotechnology, The Joint International Research Laboratory of Metabolic and Developmental Sciences, Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai, Minhang, China,CONTACT Hong-Wei Xue Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, ofAgriculture, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hong-Wei Xue
- Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, Minhang, China,Wen-Hui Lin School of Life Sciences and Biotechnology, The Joint International Research Laboratory of Metabolic and Developmental Sciences, Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
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20
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Montes C, Wang P, Liao C, Nolan TM, Song G, Clark NM, Elmore JM, Guo H, Bassham DC, Yin Y, Walley JW. Integration of multi-omics data reveals interplay between brassinosteroid and Target of Rapamycin Complex signaling in Arabidopsis. THE NEW PHYTOLOGIST 2022; 236:893-910. [PMID: 35892179 PMCID: PMC9804314 DOI: 10.1111/nph.18404] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 07/16/2022] [Indexed: 06/01/2023]
Abstract
Brassinosteroids (BRs) and Target of Rapamycin Complex (TORC) are two major actors coordinating plant growth and stress responses. Brassinosteroids function through a signaling pathway to extensively regulate gene expression and TORC is known to regulate translation and autophagy. Recent studies have revealed connections between these two pathways, but a system-wide view of their interplay is still missing. We quantified the level of 23 975 transcripts, 11 183 proteins, and 27 887 phosphorylation sites in wild-type Arabidopsis thaliana and in mutants with altered levels of either BRASSINOSTEROID INSENSITIVE 2 (BIN2) or REGULATORY ASSOCIATED PROTEIN OF TOR 1B (RAPTOR1B), two key players in BR and TORC signaling, respectively. We found that perturbation of BIN2 or RAPTOR1B levels affects a common set of gene-products involved in growth and stress responses. Furthermore, we used the multi-omic data to reconstruct an integrated signaling network. We screened 41 candidate genes identified from the reconstructed network and found that loss of function mutants of many of these proteins led to an altered BR response and/or modulated autophagy activity. Altogether, these results establish a predictive network that defines different layers of molecular interactions between BR- or TORC-regulated growth and autophagy.
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Affiliation(s)
- Christian Montes
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIA50011USA
| | - Ping Wang
- Department of Genetics, Development and Cell BiologyIowa State UniversityAmesIA50011USA
| | - Ching‐Yi Liao
- Department of Genetics, Development and Cell BiologyIowa State UniversityAmesIA50011USA
| | - Trevor M. Nolan
- Department of Genetics, Development and Cell BiologyIowa State UniversityAmesIA50011USA
- Department of BiologyDuke UniversityDurhamNC27708USA
| | - Gaoyuan Song
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIA50011USA
| | - Natalie M. Clark
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIA50011USA
| | - J. Mitch Elmore
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIA50011USA
- USDA‐ARS Cereal Disease LaboratoryUniversity of MinnesotaSt PaulMN55108USA
| | - Hongqing Guo
- Department of Genetics, Development and Cell BiologyIowa State UniversityAmesIA50011USA
| | - Diane C. Bassham
- Department of Genetics, Development and Cell BiologyIowa State UniversityAmesIA50011USA
| | - Yanhai Yin
- Department of Genetics, Development and Cell BiologyIowa State UniversityAmesIA50011USA
- Plant Sciences InstituteIowa State UniversityAmesIA50011USA
| | - Justin W. Walley
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIA50011USA
- Plant Sciences InstituteIowa State UniversityAmesIA50011USA
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21
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Autophagy Mediates MMP-2 Expression in Glaucomatous Trabecular Meshwork Cells. J Ophthalmol 2022; 2022:6026464. [PMID: 36211598 PMCID: PMC9536984 DOI: 10.1155/2022/6026464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 07/25/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the effect of 3-methyladenine (3-MA) and starvation on the expression of matrix metalloproteinase (MMP-2) in patients with primary open-angle glaucoma. Methods Primary TM cells were cultured and divided into three groups. The control group was treated with a normal medium, the 3-MA group was stimulated with 3-MA, and the starvation group received nutrient depletion by replacing the normal media with Earle's balanced salt solution. Cellular mRNA and protein were measured at different 3-MA concentrations and starvation time periods. The level of autophagy was accessed by monodansylcadaverine fluorescent staining and expression of specific autophagy-related genes, light chain 3 (LC3), and Beclin1. The effects of 3-MA and starvation on cell proliferation were determined with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay kit. The mRNA and protein expression of LC3-II, Beclin1, and MMP-2 were measured by reverse transcription-polymerase chain reaction and western blot, respectively. Results Compared to the control group, starvation significantly upregulated LC3-II and Beclin1 in TM cells after 3 h of stimulation, which peaked at 6 h and 9 h, respectively. Increased MDC-labeled cells were also observed. Starvation downregulated the expression of MMP-2. On the contrary, 3-MA suppressed the activation of autophagy, as shown by the marked downregulation of LC3-II and Beclin1. The expressions of MMP-2 were higher in the 3-MA group compared to the control group, reaching a peak at a concentration of 5 mM. Conclusion Autophagy may be involved in the pathogenesis of POAG via regulating the expression of MMP-2 and, subsequently, the deposition of the extracellular matrix.
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22
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Wang P, Clark NM, Nolan TM, Song G, Whitham OG, Liao CY, Montes-Serey C, Bassham DC, Walley JW, Yin Y, Guo H. FERONIA functions through Target of Rapamycin (TOR) to negatively regulate autophagy. FRONTIERS IN PLANT SCIENCE 2022; 13:961096. [PMID: 36082288 PMCID: PMC9446147 DOI: 10.3389/fpls.2022.961096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 07/29/2022] [Indexed: 05/20/2023]
Abstract
FERONIA (FER) receptor kinase plays versatile roles in plant growth and development, biotic and abiotic stress responses, and reproduction. Autophagy is a conserved cellular recycling process that is critical for balancing plant growth and stress responses. Target of Rapamycin (TOR) has been shown to be a master regulator of autophagy. Our previous multi-omics analysis with loss-of-function fer-4 mutant implicated that FER functions in the autophagy pathway. We further demonstrated here that the fer-4 mutant displayed constitutive autophagy, and FER is required for TOR kinase activity measured by S6K1 phosphorylation and by root growth inhibition assay to TOR kinase inhibitor AZD8055. Taken together, our study provides a previously unknown mechanism by which FER functions through TOR to negatively regulate autophagy.
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Affiliation(s)
- Ping Wang
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
| | - Natalie M. Clark
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
| | - Trevor M. Nolan
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
| | - Gaoyuan Song
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
| | - Olivia G. Whitham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
| | - Ching-Yi Liao
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
| | - Christian Montes-Serey
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
| | - Diane C. Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
| | - Justin W. Walley
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
- Plant Sciences Institute, Iowa State University, Ames, IA, United States
| | - Yanhai Yin
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
- Plant Sciences Institute, Iowa State University, Ames, IA, United States
| | - Hongqing Guo
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, United States
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23
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Xuan L, Wu H, Li J, Yuan G, Huang Y, Lian C, Wang X, Yang T, Wang C. Hydrogen sulfide reduces cell death through regulating autophagy during submergence in Arabidopsis. PLANT CELL REPORTS 2022; 41:1531-1548. [PMID: 35507055 DOI: 10.1007/s00299-022-02872-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 04/09/2022] [Indexed: 06/14/2023]
Abstract
Hydrogen sulfide positively regulates autophagy and the expression of hypoxia response-related genes under submergence to enhance the submergence tolerance of Arabidopsis. Flooding seriously endangers agricultural production, and it is quite necessary to explore the mechanism of plant response to submergence for improving crop yield. Both hydrogen sulfide (H2S) and autophagy are involved in the plant response to submergence. However, the mechanisms by which H2S and autophagy interact and influence submergence tolerance have not been thoroughly elucidated. Here, we reported that exogenous H2S pretreatment increased the level of endogenous H2S and alleviated plant cell death under submergence. And transgenic lines decreased in the level of endogenous H2S, L-cysteine desulfurase 1 (des1) mutant and 35S::GFP-O-acetyl-L-serine(thiol)lyase A1 (OASA1)/des1-#56/#61, were sensitive to submergence, along with the lower transcript levels of hypoxia response genes, LOB DOMAIN 41 (LBD41) and HYPOXIA RESPONSIVE UNKNOWN PROTEIN 43 (HUP43). Submergence induced the formation of autophagosomes, and the autophagy-related (ATG) mutants (atg4a/4b, atg5, atg7) displayed sensitive phenotypes to submergence. Simultaneously, H2S pretreatment repressed the autophagosome producing under normal conditions, but enhanced this process under submergence by regulating the expression of ATG genes. Moreover, the mutation of DES1 aggravated the sensitivity of des1/atg5 to submergence by reducing the formation of autophagosomes under submergence. Taken together, our results demonstrated that H2S alleviated cell death through regulating autophagy and the expression of hypoxia response genes during submergence in Arabidopsis.
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Affiliation(s)
- Lijuan Xuan
- Ministry of Education, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Haijun Wu
- Ministry of Education, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Jian Li
- Ministry of Education, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Guoqiang Yuan
- Ministry of Education, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yijun Huang
- Ministry of Education, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Chengfei Lian
- Ministry of Education, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xinyu Wang
- Ministry of Education, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Tao Yang
- Ministry of Education, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
| | - Chongying Wang
- Ministry of Education, Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
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24
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Overexpression of PpSnRK1α in Tomato Increased Autophagy Activity under Low Nutrient Stress. Int J Mol Sci 2022; 23:ijms23105464. [PMID: 35628273 PMCID: PMC9141306 DOI: 10.3390/ijms23105464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/11/2022] [Accepted: 05/11/2022] [Indexed: 11/26/2022] Open
Abstract
Plants suffer from a variety of environmental stresses during their growth and development. The evolutionarily conserved sucrose nonfermenting kinase 1-related protein kinase 1 (SnRK1) plays a central role in the regulation of energy homeostasis in response to stresses. In plant cells, autophagy is a degradation process occurring during development or under stress, such as nutrient starvation. In recent years, SnRK1 signaling has been reported to be an upstream activator of autophagy. However, these studies all focused on the regulatory effect of SnRK1 on TOR signaling and the autophagy-related gene 1 (ATG1) complex. In this study, overexpression of the gene encoding the Prunus persica SnRK1 α subunit (PpSnRK1α) in tomato improved the photosynthetic rates and enhanced the resistance to low nutrient stress (LNS). Overexpression of PpSnRK1α increased autophagy activity and upregulated the expression of seven autophagy-related genes (ATGs). The transcriptional levels of SlSnRK2 family genes were altered significantly by PpSnRK1α, signifying that PpSnRK1α may be involved in the ABA signaling pathway. Further analysis showed that PpSnRK1α not only activated autophagy by inhibiting target of rapamycin (TOR) signaling but also enhanced ABA-induced autophagy. This indicates that PpSnRK1α regulates the photosynthetic rate and induces autophagy, and then responds to low nutrient stress.
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25
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Liu R, Zhang R, Yang Y, Liu X, Gong Q. Monitoring Autophagy in Rice With GFP-ATG8 Marker Lines. FRONTIERS IN PLANT SCIENCE 2022; 13:866367. [PMID: 35548298 PMCID: PMC9083259 DOI: 10.3389/fpls.2022.866367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/28/2022] [Indexed: 06/15/2023]
Abstract
Autophagy is a conserved intracellular trafficking pathway for bulk degradation and recycling of cellular components in eukaryotes. The hallmark of autophagy is the formation of double-membraned vesicles termed autophagosomes, which selectively or non-selectively pack up various macromolecules and organelles and deliver these cargoes into the vacuole/lysosome. Like all other membrane trafficking pathways, the observation of autophagy is largely dependent on marker lines. ATG8/LC3 is the only autophagy-related (ATG) protein that, through a covalent bond to phosphatidylethanolamine (PE), associates tightly with the isolation membrane/pre-autophagosomal structure (PAS), the growing phagophore, the mature autophagosome, and the autophagic bodies. Therefore, fluorescent protein (FP)-tagged ATG8 had been widely used for monitoring autophagosome formation and autophagic flux. In rice (Oryza sativa), FP-OsATG8 driven by Cauliflower mosaic virus (CaMV) 35S promoter had been used for imaging autophagosome and autophagic bodies. Here, we constructed three vectors carrying GFP-OsATG8a, driven by 35S, ubiquitin, and the endogenous ATG8a promoter, individually. Then, we compared them for their suitability in monitoring autophagy, by observing GFP-ATG8a puncta formation in transiently transformed rice protoplasts, and by tracking the autophagic flux with GFP-ATG8 cleavage assay in rice stable transgenic lines. GFP-Trap immunoprecipitation and mass spectrometry were also performed with the three marker lines to show that they can be used reliably for proteomic studies. We found out that the ubiquitin promoter is the best for protoplast imaging. Transgenic rice seedlings of the three marker lines showed comparable performance in autophagic flux measurement using the GFP-ATG8 cleavage assay. Surprisingly, the levels of GFP-ATG8a transcripts and protein contents were similar in all marker lines, indicating post-transcriptional regulation of the transgene expression by a yet unknown mechanism. These marker lines can serve as useful tools for autophagy studies in rice.
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Affiliation(s)
- Rui Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Rongxue Zhang
- Tianjin Key Laboratory of Crop Genetics and Breeding, Tianjin Agricultural University, Tianjin, China
| | - Yi Yang
- College of Life Sciences, Nankai University, Tianjin, China
| | - Xuejun Liu
- Tianjin Key Laboratory of Crop Genetics and Breeding, Tianjin Agricultural University, Tianjin, China
| | - Qingqiu Gong
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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26
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Su B, Wang A, Shan X. The role of N-myristoylation in homeostasis of brassinosteroid signaling kinase 1. PLANTA 2022; 255:73. [PMID: 35220507 DOI: 10.1007/s00425-022-03861-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/17/2022] [Indexed: 05/26/2023]
Abstract
The N-myristoylation is required for BSK1 proper plasma membrane targeting and protein turnover. Brassinosteroid (BR) signaling kinase 1 (BSK1), with a myristoylation site at its N-terminus to anchor at plasma membrane (PM), is involved in BR-regulated plant growth and flg22-triggered immunity responses. However, little is known about the role of N-myristoylation in BSK1 protein homeostasis. Here, we revealed that N-myristoylation is critical to the PM targeting and protein stability of BSK1. The N-myristoylation-deficient mutant BSK1G2A mainly distributed in the cytoplasm and retained in the endoplasmic reticulum. We further found that the BSK1G2A proteins were unstable and degraded through ATG8e-labled autophagic pathway. This study provides a new insight into the regulation of plant protein homeostasis.
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Affiliation(s)
- Bodan Su
- School of Life Sciences, Tsinghua University, Beijing, 10084, China
| | - Anqi Wang
- School of Life Sciences, Tsinghua University, Beijing, 10084, China
| | - Xiaoyi Shan
- School of Life Sciences, Tsinghua University, Beijing, 10084, China.
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27
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Autophagy-Related Gene PlATG6a Is Involved in Mycelial Growth, Asexual Reproduction and Tolerance to Salt and Oxidative Stresses in Peronophythora litchii. Int J Mol Sci 2022; 23:ijms23031839. [PMID: 35163762 PMCID: PMC8836449 DOI: 10.3390/ijms23031839] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/16/2021] [Accepted: 01/27/2022] [Indexed: 02/05/2023] Open
Abstract
Autophagy is ubiquitously present in eukaryotes. During this process, intracellular proteins and some waste organelles are transported into lysosomes or vacuoles for degradation, which can be reused by the cell to guarantee normal cellular metabolism. However, the function of autophagy-related (ATG) proteins in oomycetes is rarely known. In this study, we identified an autophagy-related gene, PlATG6a, encoding a 514-amino-acid protein in Peronophythora litchii, which is the most destructive pathogen of litchi. The transcriptional level of PlATG6a was relatively higher in mycelium, sporangia, zoospores and cysts. We generated PlATG6a knockout mutants using CRISPR/Cas9 technology. The P. litchii Δplatg6a mutants were significantly impaired in autophagy and vegetative growth. We further found that the Δplatg6a mutants displayed decreased branches of sporangiophore, leading to impaired sporangium production. PlATG6a is also involved in resistance to oxidative and salt stresses, but not in sexual reproduction. The transcription of peroxidase-encoding genes was down-regulated in Δplatg6a mutants, which is likely responsible for hypersensitivity to oxidative stress. Compared with the wild-type strain, the Δplatg6a mutants showed reduced virulence when inoculated on the litchi leaves using mycelia plugs. Overall, these results suggest a critical role for PlATG6a in autophagy, vegetative growth, sporangium production, sporangiophore development, zoospore release, pathogenesis and tolerance to salt and oxidative stresses in P. litchii.
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Role of Autophagy in Haematococcus lacustris Cell Growth under Salinity. PLANTS 2022; 11:plants11020197. [PMID: 35050085 PMCID: PMC8778389 DOI: 10.3390/plants11020197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/24/2021] [Accepted: 01/08/2022] [Indexed: 11/17/2022]
Abstract
The microalga Haematococcus lacustris (formerly H. pluvialis) is able to accumulate high amounts of the carotenoid astaxanthin in the course of adaptation to stresses like salinity. Technologies aimed at production of natural astaxanthin for commercial purposes often involve salinity stress; however, after a switch to stressful conditions, H. lacustris experiences massive cell death which negatively influences astaxanthin yield. This study addressed the possibility to improve cell survival in H. lacustris subjected to salinity via manipulation of the levels of autophagy using AZD8055, a known inhibitor of TOR kinase previously shown to accelerate autophagy in several microalgae. Addition of NaCl in concentrations of 0.2% or 0.8% to the growth medium induced formation of autophagosomes in H. lacustris, while simultaneous addition of AZD8055 up to a final concentration of 0.2 µM further stimulated this process. AZD8055 significantly improved the yield of H. lacustris cells after 5 days of exposure to 0.2% NaCl. Strikingly, this occurred by acceleration of cell growth, and not by acceleration of aplanospore formation. The level of astaxanthin synthesis was not affected by AZD8055. However, cytological data suggested a role of autophagosomes, lysosomes and Golgi cisternae in cell remodeling during high salt stress.
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Simoni EB, Oliveira CC, Fraga OT, Reis PAB, Fontes EPB. Cell Death Signaling From Endoplasmic Reticulum Stress: Plant-Specific and Conserved Features. FRONTIERS IN PLANT SCIENCE 2022; 13:835738. [PMID: 35185996 PMCID: PMC8850647 DOI: 10.3389/fpls.2022.835738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/10/2022] [Indexed: 05/06/2023]
Abstract
The endoplasmic reticulum (ER) stress response is triggered by any condition that disrupts protein folding and promotes the accumulation of unfolded proteins in the lumen of the organelle. In eukaryotic cells, the evolutionarily conserved unfolded protein response is activated to clear unfolded proteins and restore ER homeostasis. The recovery from ER stress is accomplished by decreasing protein translation and loading into the organelle, increasing the ER protein processing capacity and ER-associated protein degradation activity. However, if the ER stress persists and cannot be reversed, the chronically prolonged stress leads to cellular dysfunction that activates cell death signaling as an ultimate attempt to survive. Accumulating evidence implicates ER stress-induced cell death signaling pathways as significant contributors for stress adaptation in plants, making modulators of ER stress pathways potentially attractive targets for stress tolerance engineering. Here, we summarize recent advances in understanding plant-specific molecular mechanisms that elicit cell death signaling from ER stress. We also highlight the conserved features of ER stress-induced cell death signaling in plants shared by eukaryotic cells.
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Ishida H, Okashita Y, Ishida H, Hayashi M, Izumi M, Makino A, Bhuiyan NH, van Wijk KJ. GFS9 Affects Piecemeal Autophagy of Plastids in Young Seedlings of Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2021; 62:1372-1386. [PMID: 34086965 DOI: 10.1093/pcp/pcab084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 05/26/2021] [Accepted: 06/04/2021] [Indexed: 06/12/2023]
Abstract
Chloroplasts, and plastids in general, contain abundant protein pools that can be major sources of carbon and nitrogen for recycling. We have previously shown that chloroplasts are partially and sequentially degraded by piecemeal autophagy via the Rubisco-containing body. This degradation occurs during plant development and in response to the environment; however, little is known about the fundamental underlying mechanisms. To discover the mechanisms of piecemeal autophagy of chloroplasts/plastids, we conducted a forward-genetics screen following ethyl-methanesulfonate mutagenesis of an Arabidopsis (Arabidopsis thaliana) transgenic line expressing chloroplast-targeted green fluorescent protein (CT-GFP). This screen allowed us to isolate a mutant, gfs9-5, which hyperaccumulated cytoplasmic bodies labeled with CT-GFP of up to 1.0 μm in diameter in the young seedlings. We termed these structures plastid bodies (PBs). The mutant was defective in a membrane-trafficking factor, green fluorescent seed 9 (GFS9), and PB accumulation in gfs9-5 was promoted by darkness and nutrient deficiency. Transmission electron microscopy indicated that gfs9-5 hyperaccumulated structures corresponding to autophagosomes and PBs. gfs9-5 hyperaccumulated membrane-bound endogenous ATG8 proteins, transgenic yellow fluorescent protein (YFP)-ATG8e proteins and autophagosome-like structures labeled with YFP-ATG8e. The YFP-ATG8e signal was associated with the surface of plastids and their protrusions in gfs9-5. Double mutants of gfs9 and autophagy-defective 5 did not accumulate PBs. In gfs9-5, the YFP-ATG8e proteins and PBs could be delivered to the vacuole and autophagic flux was increased. We discuss a possible connection between GFS9 and autophagy and propose a potential use of gfs9-5 as a new tool to study piecemeal plastid autophagy.
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Affiliation(s)
- Hiroyuki Ishida
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Sendai 980-8572, Japan
- School of Integrative Plant Sciences, Section of Plant Biology, Cornell University, Ithaca, NY 14853, USA
| | - Yu Okashita
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Sendai 980-8572, Japan
| | - Hiromi Ishida
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Sendai 980-8572, Japan
- School of Integrative Plant Sciences, Section of Plant Biology, Cornell University, Ithaca, NY 14853, USA
| | - Makoto Hayashi
- Department of Bioscience, Nagahama Institute of Bioscience and Technology, Tamura 1266, Nagahama, Shiga 526-0829, Japan
| | - Masanori Izumi
- Center for Sustainable Resource Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Amane Makino
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Sendai 980-8572, Japan
| | - Nazmul H Bhuiyan
- School of Integrative Plant Sciences, Section of Plant Biology, Cornell University, Ithaca, NY 14853, USA
- Eurofins Lancaster Lab PSS, Richmond, VA, USA
| | - Klaas J van Wijk
- School of Integrative Plant Sciences, Section of Plant Biology, Cornell University, Ithaca, NY 14853, USA
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Brocca L, Zuccaro M, Frugis G, Mainieri D, Marrano C, Ragni L, Klein EM, Vitale A, Pedrazzini E. Two γ-zeins induce the unfolded protein response. PLANT PHYSIOLOGY 2021; 187:1428-1444. [PMID: 34618077 PMCID: PMC8566291 DOI: 10.1093/plphys/kiab367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/09/2021] [Indexed: 06/13/2023]
Abstract
The rapid, massive synthesis of storage proteins that occurs during seed development stresses endoplasmic reticulum (ER) homeostasis, which activates the ER unfolded protein response (UPR). However, how different storage proteins contribute to UPR is not clear. We analyzed vegetative tissues of transgenic Arabidopsis (Arabidopsis thaliana) plants constitutively expressing the common bean (Phaseolus vulgaris) soluble vacuolar storage protein PHASEOLIN (PHSL) or maize (Zea mays) prolamins (27-kDa γ-zein or 16-kDa γ-zein) that participate in forming insoluble protein bodies in the ER. We show that 16-kDa γ-zein significantly activates the INOSITOL REQUIRING ENZYME1/BASIC LEUCINE ZIPPER 60 (bZIP60) UPR branch-but not the bZIP28 branch or autophagy-leading to induction of major UPR-controlled genes that encode folding helpers that function inside the ER. Protein blot analysis of IMMUNOGLOBULIN-BINDING PROTEIN (BIP) 1 and 2, BIP3, GLUCOSE REGULATED PROTEIN 94 (GRP94), and ER-localized DNAJ family 3A (ERDJ3A) polypeptides confirmed their higher accumulation in the plant expressing 16-kDa γ-zein. Expression of 27-kDa γ-zein significantly induced only BIP3 and ERDJ3A transcription even though an increase in GRP94 and BIP1/2 polypeptides also occurred in this plant. These results indicate a significant but weaker effect of 27-kDa γ-zein compared to 16-kDa γ-zein, which corresponds with the higher availability of 16-kDa γ-zein for BIP binding, and indicates subtle protein-specific modulations of plant UPR. None of the analyzed genes was significantly induced by PHSL or by a mutated, soluble form of 27-kDa γ-zein that traffics along the secretory pathway. Such variability in UPR induction may have influenced the evolution of storage proteins with different tissue and subcellular localization.
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Affiliation(s)
- Lorenzo Brocca
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Milano 20133, Italy
| | - Melania Zuccaro
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Milano 20133, Italy
| | - Giovanna Frugis
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Monterotondo Scalo, Roma 00016, Italy
| | - Davide Mainieri
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Milano 20133, Italy
| | - Claudia Marrano
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Milano 20133, Italy
| | - Laura Ragni
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Milano 20133, Italy
| | - Eva Maria Klein
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Milano 20133, Italy
| | - Alessandro Vitale
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Milano 20133, Italy
| | - Emanuela Pedrazzini
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Milano 20133, Italy
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Luo X, Tian T, Bonnave M, Tan X, Huang X, Li Z, Ren M. The Molecular Mechanisms of Phytophthora infestans in Response to Reactive Oxygen Species Stress. PHYTOPATHOLOGY 2021; 111:2067-2079. [PMID: 33787286 DOI: 10.1094/phyto-08-20-0321-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Reactive oxygen species (ROSs) are critical for the growth, development, proliferation, and pathogenicity of microbial pathogens; however, excessive levels of ROSs are toxic. Little is known about the signaling cascades in response to ROS stress in oomycetes such as Phytophthora infestans, the causal agent of potato late blight. Here, P. infestans was used as a model system to investigate the mechanism underlying the response to ROS stress in oomycete pathogens. Results showed severe defects in sporangium germination, mycelium growth, appressorium formation, and virulence of P. infestans in response to H2O2 stress. Importantly, these phenotypes mimic those of P. infestans treated with rapamycin, the inhibitor of target of rapamycin (TOR, 1-phosphatidylinositol-3-kinase). Strong synergism occurred when P. infestans was treated with a combination of H2O2 and rapamycin, suggesting that a crosstalk exists between ROS stress and the TOR signaling pathway. Comprehensive analysis of transcriptome, proteome, and phosphorylation omics showed that H2O2 stress significantly induced the operation of the TOR-mediated autophagy pathway. Monodansylcadaverine staining showed that in the presence of H2O2 and rapamycin, the autophagosome level increased in a dosage-dependent manner. Furthermore, transgenic potatoes containing double-stranded RNA of TOR in P. infestans (PiTOR) displayed high resistance to P. infestans. Therefore, TOR is involved in the ROS response and is a potential target for control of oomycete diseases, because host-mediated silencing of PiTOR increases potato resistance to late blight.
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Affiliation(s)
- Xiumei Luo
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610000, China
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Tingting Tian
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Maxime Bonnave
- Centre for Agriculture and Agro-Industry of Hainaut Province, Ath 7800, Belgium
| | - Xue Tan
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Xiaoqing Huang
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Zhengguo Li
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Maozhi Ren
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610000, China
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450000, China
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Niu E, Liu H, Zhou H, Luo L, Wu Y, Andika IB, Sun L. Autophagy Inhibits Intercellular Transport of Citrus Leaf Blotch Virus by Targeting Viral Movement Protein. Viruses 2021; 13:2189. [PMID: 34834995 PMCID: PMC8619118 DOI: 10.3390/v13112189] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 12/12/2022] Open
Abstract
Autophagy is an evolutionarily conserved cellular-degradation mechanism implicated in antiviral defense in plants. Studies have shown that autophagy suppresses virus accumulation in cells; however, it has not been reported to specifically inhibit viral spread in plants. This study demonstrated that infection with citrus leaf blotch virus (CLBV; genus Citrivirus, family Betaflexiviridae) activated autophagy in Nicotiana benthamiana plants as indicated by the increase of autophagosome formation. Impairment of autophagy through silencing of N. benthamiana autophagy-related gene 5 (NbATG5) and NbATG7 enhanced cell-to-cell and systemic movement of CLBV; however, it did not affect CLBV accumulation when the systemic infection had been fully established. Treatment using an autophagy inhibitor or silencing of NbATG5 and NbATG7 revealed that transiently expressed movement protein (MP), but not coat protein, of CLBV was targeted by selective autophagy for degradation. Moreover, we identified that CLBV MP directly interacted with NbATG8C1 and NbATG8i, the isoforms of autophagy-related protein 8 (ATG8), which are key factors that usually bind cargo receptors for selective autophagy. Our results present a novel example in which autophagy specifically targets a viral MP to limit the intercellular spread of the virus in plants.
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Affiliation(s)
- Erbo Niu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (E.N.); (H.Z.); (L.L.)
| | - Huan Liu
- School of Modern Agriculture and Biotechnology, Ankang University, Ankang 725000, China;
| | - Hongsheng Zhou
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (E.N.); (H.Z.); (L.L.)
| | - Lian Luo
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (E.N.); (H.Z.); (L.L.)
| | - Yunfeng Wu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (E.N.); (H.Z.); (L.L.)
| | - Ida Bagus Andika
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Liying Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Xianyang 712100, China; (E.N.); (H.Z.); (L.L.)
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Chen Y, Li P, Peng Y, Xie X, Zhang Y, Jiang Y, Li T, Qin X, Li S, Yang H, Wu C, Zheng C, Zhu J, You F, Liu Y. Protective autophagy attenuates soft substrate-induced apoptosis through ROS/JNK signaling pathway in breast cancer cells. Free Radic Biol Med 2021; 172:590-603. [PMID: 34242793 DOI: 10.1016/j.freeradbiomed.2021.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 07/03/2021] [Indexed: 02/06/2023]
Abstract
Tumor microenvironments are characterized not only in terms of chemical composition, but also by physical properties such as stiffness, which influences morphology, proliferation, and fate of tumor cells. However, the underlying mechanisms between matrix stiffness and the apoptosis-autophagy balance remain largely unexplored. In this study, we cultured human breast cancer MDA-MB-231 cells on rigid (57 kPa), stiff (38 kPa) or soft (10 kPa) substrates and demonstrated that increasing autophagy levels and autophagic flux in the cells cultured on soft substrates partly attenuated soft substrate-induced apoptosis. Mechanistically, this protective autophagy is regulated by intracellular reactive oxygen species (ROS) accumulation, which triggers the downstream signals of JNK, Bcl-2 and Beclin-1. More importantly, soft substrate-induced activation of ROS/JNK signaling promotes cell apoptosis through the mitochondrial pathway, whereas it increases protective autophagy by suppressing the interaction of Bcl-2 and Beclin-1. Taken together, our data suggest that JNK is the mediator of soft substrate-induced breast cancer cell apoptosis and autophagy which is likely to be the mechanism that partly attenuates mitochondrial apoptosis. This study provides new insights into the molecular mechanism by which autophagy plays a protective role against soft substrate-induced apoptosis in human breast cancer cells.
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Affiliation(s)
- Yu Chen
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Ping Li
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Yueting Peng
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Xiaoxue Xie
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Yixi Zhang
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Ying Jiang
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Tingting Li
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Xiang Qin
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Shun Li
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Hong Yang
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Chunhui Wu
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China
| | - Chuan Zheng
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province, Hospital of Chengdu University of Traditional Chinese Medicine, No. 39 Shi-er-qiao Road, Chengdu, 610072, Sichuan, PR China
| | - Jie Zhu
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province, Hospital of Chengdu University of Traditional Chinese Medicine, No. 39 Shi-er-qiao Road, Chengdu, 610072, Sichuan, PR China
| | - Fengming You
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province, Hospital of Chengdu University of Traditional Chinese Medicine, No. 39 Shi-er-qiao Road, Chengdu, 610072, Sichuan, PR China
| | - Yiyao Liu
- Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, PR China; TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province, Hospital of Chengdu University of Traditional Chinese Medicine, No. 39 Shi-er-qiao Road, Chengdu, 610072, Sichuan, PR China.
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Wang H, Ding Z, Gou M, Hu J, Wang Y, Wang L, Wang Y, Di T, Zhang X, Hao X, Wang X, Yang Y, Qian W. Genome-wide identification, characterization, and expression analysis of tea plant autophagy-related genes (CsARGs) demonstrates that they play diverse roles during development and under abiotic stress. BMC Genomics 2021; 22:121. [PMID: 33596831 PMCID: PMC7891152 DOI: 10.1186/s12864-021-07419-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 01/31/2021] [Indexed: 12/12/2022] Open
Abstract
Background Autophagy, meaning ‘self-eating’, is required for the degradation and recycling of cytoplasmic constituents under stressful and non-stressful conditions, which helps to maintain cellular homeostasis and delay aging and longevity in eukaryotes. To date, the functions of autophagy have been heavily studied in yeast, mammals and model plants, but few studies have focused on economically important crops, especially tea plants (Camellia sinensis). The roles played by autophagy in coping with various environmental stimuli have not been fully elucidated to date. Therefore, investigating the functions of autophagy-related genes in tea plants may help to elucidate the mechanism governing autophagy in response to stresses in woody plants. Results In this study, we identified 35 C. sinensis autophagy-related genes (CsARGs). Each CsARG is highly conserved with its homologues from other plant species, except for CsATG14. Tissue-specific expression analysis demonstrated that the abundances of CsARGs varied across different tissues, but CsATG8c/i showed a degree of tissue specificity. Under hormone and abiotic stress conditions, most CsARGs were upregulated at different time points during the treatment. In addition, the expression levels of 10 CsARGs were higher in the cold-resistant cultivar ‘Longjing43’ than in the cold-susceptible cultivar ‘Damianbai’ during the CA period; however, the expression of CsATG101 showed the opposite tendency. Conclusions We performed a comprehensive bioinformatic and physiological analysis of CsARGs in tea plants, and these results may help to establish a foundation for further research investigating the molecular mechanisms governing autophagy in tea plant growth, development and response to stress. Meanwhile, some CsARGs could serve as putative molecular markers for the breeding of cold-resistant tea plants in future research. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07419-2.
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Affiliation(s)
- Huan Wang
- College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, China
| | - Zhaotang Ding
- College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, China
| | - Mengjie Gou
- College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, China
| | - Jianhui Hu
- College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, China
| | - Yu Wang
- College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, China
| | - Lu Wang
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, China.,Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, 310008, China
| | - Yuchun Wang
- College of Agriculture and Food Science, Zhejiang A&F University, Hangzhou, 311300, China
| | - Taimei Di
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, China.,Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, 310008, China
| | - Xinfu Zhang
- College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xinyuan Hao
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, China.,Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, 310008, China
| | - Xinchao Wang
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, China.,Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, 310008, China
| | - Yajun Yang
- National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, China.,Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, 310008, China
| | - Wenjun Qian
- College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, China.
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Hypoxia-Induced Autophagy Enhances Cisplatin Resistance in Human Bladder Cancer Cells by Targeting Hypoxia-Inducible Factor-1 α. J Immunol Res 2021; 2021:8887437. [PMID: 33681390 PMCID: PMC7904373 DOI: 10.1155/2021/8887437] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 12/11/2020] [Accepted: 02/04/2021] [Indexed: 01/10/2023] Open
Abstract
Purpose To investigate the effect of hypoxia on chemoresistance and the underlying mechanism in bladder cancer cells. Methods BIU-87 bladder cancer cell line was treated with cisplatin under hypoxic and normoxic conditions and tested using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and Western blotting. All the data were expressed as mean ± standard error from three independent experiments and analyzed by multiple t-tests. Results Apoptosis of bladder cancer cells caused by cisplatin was attenuated in hypoxic conditions. Hypoxia enhanced autophagy caused by cisplatin. The autophagy inhibitor and HIF-1α inhibitor can reverse the chemoresistance in hypoxic condition. Apoptosis and autophagy of bladder cancer cells were downregulated by HIF-1α inhibitor YC-1. Hypoxia-induced autophagy enhanced chemoresistance to cisplatin via the HIF-1 signaling pathway. Conclusion Resistance to cisplatin in BIU-87 bladder cancer cells under hypoxic conditions can be explained by activation of autophagy, which is regulated by HIF-1α-associated signaling pathways. The hypoxia–autophagy pathway may be a target for improving the efficacy of cisplatin chemotherapy in bladder cancer.
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Kazibwe Z, Soto-Burgos J, MacIntosh GC, Bassham DC. TOR mediates the autophagy response to altered nucleotide homeostasis in an RNase mutant. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:6907-6920. [PMID: 32905584 DOI: 10.1093/jxb/eraa410] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 09/06/2020] [Indexed: 06/11/2023]
Abstract
The Arabidopsis thaliana T2 family endoribonuclease RNS2 localizes to the vacuole and functions in rRNA degradation. Loss of RNS2 activity impairs rRNA turnover and leads to constitutive autophagy, a process for degradation of cellular components. Autophagy is normally activated during environmental stress and is important for stress tolerance and homeostasis. Here we show that restoration of cytosolic purine nucleotide levels rescues the constitutive autophagy phenotype of rns2-2 seedlings, whereas inhibition of purine synthesis induces autophagy in wild-type seedlings. rns2-2 seedlings have reduced activity of the target of rapamycin (TOR) kinase complex, a negative regulator of autophagy, and this phenotype is rescued by addition of inosine to increase purine levels. Activation of TOR in rns2-2 by exogenous auxin blocks the enhanced autophagy, indicating a possible involvement of the TOR signaling pathway in the activation of autophagy in the rns2-2 mutant. Our data suggest a model in which loss of rRNA degradation in rns2-2 leads to a reduction in cytoplasmic nucleotide concentrations, which in turn inhibits TOR activity, leading to activation of autophagy to restore homeostasis.
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Affiliation(s)
- Zakayo Kazibwe
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Junmarie Soto-Burgos
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Gustavo C MacIntosh
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
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Yin Y, Guo Z, Chen K, Tian T, Tan J, Chen X, Chen J, Yang B, Tang S, Peng K, Liu S, Liang Y, Zhang K, Yu L, Li M. Ultra-high α-linolenic acid accumulating developmental defective embryo was rescued by lysophosphatidic acid acyltransferase 2. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:2151-2167. [PMID: 32573846 DOI: 10.1111/tpj.14889] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 05/20/2023]
Abstract
For decades, genetic engineering approaches to produce unusual fatty acids (UFAs) in crops has reached a bottleneck, including reduced seed oil production and seed vigor. Currently, plant models in the field of research are primarily used to investigate defects in oil production and seedling development, while the role of UFAs in embryonic developmental defects remains unknown. In this study, we developed a transgenic Arabidopsis plant model, in which the embryo exhibits severely wrinkled appearance owing to α-linolenic acid (ALA) accumulation. RNA-sequencing analysis in the defective embryo suggested that brassinosteroid synthesis, FA synthesis and photosynthesis were inhibited, while FA degradation, endoplasmic reticulum stress and oxidative stress were activated. Lipidomics analysis showed that ultra-accumulated ALA is released from phosphatidylcholine as a free FA in cells, inducing severe endoplasmic reticulum and oxidative stress. Furthermore, we identified that overexpression of lysophosphatidic acid acyltransferase 2 rescued the defective phenotype. In the rescue line, the pool capacity of the Kennedy pathway was increased, and the esterification of ALA indirectly to triacylglycerol was enhanced to avoid stress. This study provides a plant model that aids in understanding the molecular mechanism of embryonic developmental defects and generates strategies to produce higher levels of UFAs.
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Affiliation(s)
- Yongtai Yin
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resource Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, 438000, China
| | - Zhenyi Guo
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Kang Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Tian Tian
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jiajun Tan
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xinfeng Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jing Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Bing Yang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Shuyan Tang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Kangfu Peng
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Si Liu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yu Liang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Kai Zhang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Longjiang Yu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Maoteng Li
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resource Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, 438000, China
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Huang X, Chen S, Yang X, Yang X, Zhang T, Zhou G. Friend or Enemy: A Dual Role of Autophagy in Plant Virus Infection. Front Microbiol 2020; 11:736. [PMID: 32373106 PMCID: PMC7186577 DOI: 10.3389/fmicb.2020.00736] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 03/30/2020] [Indexed: 11/20/2022] Open
Abstract
Autophagy is a primary protective process that involves removing damaged organelles or dysfunctional proteins in eukaryotes. The autophagy pathway not only maintains cellular homeostasis, but also modulates the host's cellular response to pathogen infection. Several studies proved that autophagy plays a dominant role in plant fitness and immunity. As intracellular parasites, the replication and spread of viruses entirely rely upon the molecular machinery of the host cell, including the autophagy process. Plant viruses severely affect crop yields and quality. During infection, complex interactions occur between viral proteins and host factors in relation to plant defense and virus counter-defense. An increasing number of studies demonstrated that plants use autophagy to eliminate and inhibit viruses; some viruses were shown to manipulate the process of autophagy to promote their own replication and survival in plant cells. In this review, we summarize recent advances in plant autophagy, with an emphasis on the role of autophagy in plant virus infection.
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Affiliation(s)
- Xiuqin Huang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| | - Siping Chen
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| | - Xiaorong Yang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| | - Xin Yang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| | - Tong Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| | - Guohui Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
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Abstract
Plants balance their competing requirements for growth and stress tolerance via a sophisticated regulatory circuitry that controls responses to the external environments. We have identified a plant-specific gene, COST1 (constitutively stressed 1), that is required for normal plant growth but negatively regulates drought resistance by influencing the autophagy pathway. An Arabidopsis thaliana cost1 mutant has decreased growth and increased drought tolerance, together with constitutive autophagy and increased expression of drought-response genes, while overexpression of COST1 confers drought hypersensitivity and reduced autophagy. The COST1 protein is degraded upon plant dehydration, and this degradation is reduced upon treatment with inhibitors of the 26S proteasome or autophagy pathways. The drought resistance of a cost1 mutant is dependent on an active autophagy pathway, but independent of other known drought signaling pathways, indicating that COST1 acts through regulation of autophagy. In addition, COST1 colocalizes to autophagosomes with the autophagosome marker ATG8e and the autophagy adaptor NBR1, and affects the level of ATG8e protein through physical interaction with ATG8e, indicating a pivotal role in direct regulation of autophagy. We propose a model in which COST1 represses autophagy under optimal conditions, thus allowing plant growth. Under drought, COST1 is degraded, enabling activation of autophagy and suppression of growth to enhance drought tolerance. Our research places COST1 as an important regulator controlling the balance between growth and stress responses via the direct regulation of autophagy.
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Laterals take it better - Emerging and young lateral roots survive lethal salinity longer than the primary root in Arabidopsis. Sci Rep 2020; 10:3291. [PMID: 32094490 PMCID: PMC7040039 DOI: 10.1038/s41598-020-60163-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 02/06/2020] [Indexed: 11/16/2022] Open
Abstract
Plant responses to salinity have been extensively studied over the last decades. Despite the vast accumulated knowledge, the ways Arabidopsis lateral roots (LR) cope with lethal salinity has not been fully resolved. Here we compared the primary root (PR) and the LR responses during events leading to lethal salinity (NaCl 200 mM) in Arabidopsis. We found that the PR and young LR responded differently to lethal salinity: While the PR died, emerging and young LR’s remained strikingly viable. Moreover, “age acquired salt tolerance” (AAST) was observed in the PR. During the 2 days after germination (DAG) the PR was highly sensitive, but at 8 DAG there was a significant increase in the PR cell survival. Nevertheless, the young LR exhibited an opposite pattern and completely lost its salinity tolerance, as it elongated beyond 400 µm. Examination of several cell death signatures investigated in the young LR showed no signs of an active programmed cell death (PCD) during lethal salinity. However, Autophagic PCD (A-PCD) but not apoptosis-like PCD (AL-PCD) was found to be activated in the PR during the high salinity conditions. We further found that salinity induced NADPH oxidase activated ROS, which were more highly distributed in the young LR compared to the PR, is required for the improved viability of the LR during lethal salinity conditions. Our data demonstrated a position-dependent resistance of Arabidopsis young LR to high salinity. This response can lead to identification of novel salt stress coping mechanisms needed by agriculture during the soil salinization challenge.
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Hu S, Ye H, Cui Y, Jiang L. AtSec62 is critical for plant development and is involved in ER-phagy in Arabidopsis thaliana. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:181-200. [PMID: 31483571 PMCID: PMC7028082 DOI: 10.1111/jipb.12872] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 08/31/2019] [Indexed: 05/11/2023]
Abstract
The endoplasmic reticulum (ER) is the major site for protein folding in eukaryotic cells. ER homeostasis is essential for the development of an organism, whereby the unfolded protein response (UPR) within the ER is precisely regulated. ER-phagy is a newly identified selective autophagic pathway for removal of misfolded or unfolded proteins within the ER in mammalian cells. Sec62, a component of the translocon complex, was recently characterized as an ER-phagy receptor during the ER stress recovery phase in mammals. In this study, we demonstrated that the Arabidopsis Sec62 (AtSec62) is required for plant development and might function as an ER-phagy receptor in plants. We showed that AtSec62 is an ER-localized membrane protein with three transmembrane domains (TMDs) with its C-terminus facing to the ER lumen. AtSec62 is required for plant development because atsec62 mutants display impaired vegetative growth, abnormal pollen and decreased fertility. atsec62 mutants are sensitive towards tunicamycin (TM)-induced ER stress, whereas overexpression of AtSec62 subsequently enhances stress tolerance during the ER stress recovery phase. Moreover, YFP-AtSec62 colocalizes with the autophagosome marker mCh-Atg8e in ring-like structures upon ER stress induction. Taken together, these data provide evidence for the pivotal roles of AtSec62 in plant development and ER-phagy.
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Affiliation(s)
- Shuai Hu
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life SciencesThe Chinese University of Hong KongHong KongChina
| | - Hao Ye
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life SciencesThe Chinese University of Hong KongHong KongChina
| | - Yong Cui
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life SciencesThe Chinese University of Hong KongHong KongChina
| | - Liwen Jiang
- Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life SciencesThe Chinese University of Hong KongHong KongChina
- CUHK Shenzhen Research InstituteThe Chinese University of Hong KongShenzhen518057China
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Kajikawa M, Fukuzawa H. Algal Autophagy Is Necessary for the Regulation of Carbon Metabolism Under Nutrient Deficiency. FRONTIERS IN PLANT SCIENCE 2020; 11:36. [PMID: 32117375 PMCID: PMC7012896 DOI: 10.3389/fpls.2020.00036] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/13/2020] [Indexed: 05/04/2023]
Abstract
Autophagy is a mechanism to recycle intracellular constituents such as amino acids and other carbon- and nitrogen (N)-containing compounds. Although autophagy-related (ATG) genes required for autophagy are encoded by many algal genomes, their functional importance in microalgae in nutrient-deficiency has not been appraised using ATG-defective mutants. Recently, by characterization of an insertional mutant of the ATG8 encoding a ubiquitin-like protein indispensable for autophagosome formation in a green alga Chlamydomonas reinhardtii, we have provided evidence that supports the following notions. ATG8 protein is required for the degradation of lipid droplets and triacylglycerol (TAG) triggered by resupply of N to cell culture in N-deficient conditions. ATG8 protein is also necessary for starch accumulation under phosphorus-deficient conditions. Algal autophagy is not necessary for inheritance of chloroplast and mitochondrial genomes. In this review, we discuss the physiological roles of algal autophagy associated with nutrient deficiency revealed by the genetic and biochemical analyses using disruption mutants and reagents that inhibit the fatty acid biosynthesis and vacuolar H+-ATPase.
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Wojciechowska N, Smugarzewska I, Marzec-Schmidt K, Zarzyńska-Nowak A, Bagniewska-Zadworna A. Occurrence of autophagy during pioneer root and stem development in Populus trichocarpa. PLANTA 2019; 250:1789-1801. [PMID: 31451904 DOI: 10.1007/s00425-019-03265-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 08/19/2019] [Indexed: 05/26/2023]
Abstract
Autophagy is involved in developmentally programmed cell death and is identified during the early development of phloem, as well as xylem with a dual role, as both an inducer and executioner of cell death. The regulation of primary and secondary development of roots and stems is important for the establishment of root systems and for the overall survival of trees. The molecular and cellular basis of the autophagic processes, which are used at distinct moments during the growth of both organs, is crucial to understand the regulation of their development. To address this, we use Populus trichocarpa seedlings grown in a rhizotron system to examine the autophagy processes involved in root and stem development. To monitor the visual aspects of autophagy, transmission electron microscopy (TEM) and immunolocalization of AuTophaGy-related protein (ATG8) enabled observations of the phenomenon at a structural level. To gain further insight into the autophagy process at the protein and molecular level, we evaluated the expression of ATG gene transcripts and ATG protein levels. Alternations in the expression level of specific ATG genes and localization of ATG8 proteins were observed during the course of root or stem primary and secondary development. Specifically, ATG8 was present in the cells exhibiting autophagy, during the differentiation and early development of xylem and phloem tissues, including both xylary and extraxylary fibers. Ultrastructural observations revealed tonoplast invagination with the formation of autophagic-like bodies. Additionally, the accumulation of autophagosomes was identifiable during the differentiation of xylem in both organs, long before the commencement of cell death. Taken together, these results provide evidence in support of the dual role of autophagy in developmental PCD. A specific role of the controller of cell death, which is a committed step with the release of hydrolytic enzymes from the vacuole and final digestion of protoplast, from which there is no return once initiated, is only attributed to mega-autophagy.
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Affiliation(s)
- Natalia Wojciechowska
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland
| | - Iga Smugarzewska
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland
| | - Katarzyna Marzec-Schmidt
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland
| | - Aleksandra Zarzyńska-Nowak
- Department of Virology and Bacteriology, Institute of Plant Protection-National Research Institute, Wł. Węgorka 20, 60-318, Poznań, Poland
| | - Agnieszka Bagniewska-Zadworna
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland.
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Svobodníková L, Kummerová M, Zezulka Š, Babula P. Possible use of a Nicotiana tabacum 'Bright Yellow 2' cell suspension as a model to assess phytotoxicity of pharmaceuticals (diclofenac). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 182:109369. [PMID: 31238115 DOI: 10.1016/j.ecoenv.2019.109369] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/13/2019] [Accepted: 06/18/2019] [Indexed: 05/21/2023]
Abstract
Growth and developmental changes in plants induced by pharmaceuticals reflect changes in processes at the cellular and subcellular levels. Due to their growth and cellular characteristics, plant cell suspension cultures can be a suitable model for assessing toxicity. In this study, 10-1000 μg/L of the non-steroidal anti-inflammatory drug diclofenac (DCF) decreased the viability of Nicotiana tabacum BY-2 cells after 24 h of treatment. Further, 0.1-10 mg/L DCF diminished the density of the cell suspension by 9-46% after 96 h of treatment, but at 1 and 10 μg/L, DCF increased the density by 13% and 5%, respectively, after 120 h. These changes were accompanied by increased production of total reactive oxygen species (ROS) and mitochondrial superoxide (up to 17-fold and 5-fold, respectively), and a decrease in the mitochondrial membrane potential (by ∼64%) especially at 1000 μg/L DCF. The increased ROS production was accompanied by decrease in level of reactive nitrogen species (RNS; by 36%) and total thiols (by 61%). Damage to BY-2 cells was evidenced by accumulation of neutral red in acidic compartments (up to 10-fold at 1000 μg/L DCF), and increase of autophagic vacuole formation (up to 8-fold at 1000 μg/L DCF). Furthermore, irregular or stretched nuclei were observed in nearly 27% and 50% of cells at 100 and 1000 μg/L DCF, respectively. Highest levels of chromatin condensation (11% of cells) and apoptotic DNA fragmentation (7%) were found at 10 μg/L DCF. The results revealed a significant effect of DCF on BY-2 cells after 24 h of exposure. Changes in the growth and viability parameters were indisputably related to ROS and RNS production, changes in mitochondrial function, and possible activation of processes leading to cell death.
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Affiliation(s)
- Lucie Svobodníková
- Department of Plant Physiology and Anatomy, Institute of Experimental Biology, Faculty of Science, Masaryk University Brno, Kotlářská 2, 611 37, Brno, Czech Republic.
| | - Marie Kummerová
- Department of Plant Physiology and Anatomy, Institute of Experimental Biology, Faculty of Science, Masaryk University Brno, Kotlářská 2, 611 37, Brno, Czech Republic
| | - Štěpán Zezulka
- Department of Plant Physiology and Anatomy, Institute of Experimental Biology, Faculty of Science, Masaryk University Brno, Kotlářská 2, 611 37, Brno, Czech Republic
| | - Petr Babula
- Department of Physiology, Faculty of Medicine, Masaryk University Brno, Kamenice 753/5, 625 00, Brno, Czech Republic
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OsATG8c-Mediated Increased Autophagy Regulates the Yield and Nitrogen Use Efficiency in Rice. Int J Mol Sci 2019; 20:ijms20194956. [PMID: 31597279 PMCID: PMC6801700 DOI: 10.3390/ijms20194956] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 12/25/2022] Open
Abstract
Autophagy, a conserved pathway in eukaryotes, degrades and recycles cellular components, thus playing an important role in nitrogen (N) remobilization. N plays an important role in the growth and development of plants, which also affects plant yield and quality. In this research, it was found that the transcriptional level of a core autophagy gene of rice (Oryza sativa), OsATG8c, was increased during N starvation conditions. It was found that the overexpression of OsATG8c significantly enhanced the activity of autophagy and that the number of autophagosomes, dwarfed the plant height and increased the effective tillers’ number and yield. The nitrogen uptake efficiency (NUpE) and nitrogen use efficiency (NUE) significantly increased in the transgenic rice under both optimal and suboptimal N conditions. Based on our results, OsATG8c is considered to be a good candidate gene for increasing NUE, especially under suboptimal field conditions.
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Zhen X, Xu F, Zhang W, Li N, Li X. Overexpression of rice gene OsATG8b confers tolerance to nitrogen starvation and increases yield and nitrogen use efficiency (NUE) in Arabidopsis. PLoS One 2019; 14:e0223011. [PMID: 31553788 PMCID: PMC6760796 DOI: 10.1371/journal.pone.0223011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 09/11/2019] [Indexed: 12/11/2022] Open
Abstract
Nitrogen (N) is an important element required for plant growth and development, which also affects plant yield and quality. Autophagy, a conserved pathway in eukaryotes, degrades and recycles cellular components, thus playing an important role in N remobilization. However, only a few autophagy genes related to N remobilization in rice (Oryza sativa) have been reported. Here, we identified a core autophagy gene in rice, OsATG8b, with increased expression levels under N starvation conditions. It was investigated the function of OsATG8b by generating three independent homozygous 35S-OsATG8b transgenic Arabidopsis thaliana lines. The overexpression of OsATG8b significantly enhanced autophagic flux in the transgenic Arabidopsis plants. It was also showed that over-expressing OsATG8b promoted growth and development of Arabidopsis, in which the rosette leaves were larger than those of the wild type (WT), and the yield increased significantly by 25.25%. In addition, the transgenic lines accumulated more N in seeds than in the rosette leaves. Further examination revealed that overexpression of OsATG8b could effectively alleviate the growth inhibition of transgenic Arabidopsis under nitrogen (N) stress. N partitioning studies revealed that nitrogen-harvest index (NHI) and nitrogen use efficiency (NUE) were significantly increased in the transgenic Arabidopsis, as well as the 15N-tracer experiments revealing that the remobilization of N to seeds in the OsATG8b-overexpressing transgenic Arabidopsis was high and more than WT. Based on our findings, we consider OsATG8b to be a great candidate gene to increase NUE and yield, especially under suboptimal field conditions.
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Affiliation(s)
- Xiaoxi Zhen
- Rice Research Institute of Shenyang Agricultural University, Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Key Laboratory of Northeast Rice Biology and Genetics and Breeding, Ministry of Agriculture, Shenyang, China
| | - Fan Xu
- Rice Research Institute of Shenyang Agricultural University, Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Key Laboratory of Northeast Rice Biology and Genetics and Breeding, Ministry of Agriculture, Shenyang, China
- * E-mail: (FX); (WZ)
| | - Wenzhong Zhang
- Rice Research Institute of Shenyang Agricultural University, Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Key Laboratory of Northeast Rice Biology and Genetics and Breeding, Ministry of Agriculture, Shenyang, China
- * E-mail: (FX); (WZ)
| | - Nan Li
- Shen Yang Product Quality Supervision and Inspection Institute, Shenyang, China
| | - Xin Li
- Rice Research Institute of Shenyang Agricultural University, Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Key Laboratory of Northeast Rice Biology and Genetics and Breeding, Ministry of Agriculture, Shenyang, China
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Novel Derivatives of Deoxycholic Acid Bearing Linear Aliphatic Diamine and Aminoalcohol Moieties and their Cyclic Analogs at the C3 Position: Synthesis and Evaluation of Their In Vitro Antitumor Potential. Molecules 2019; 24:molecules24142644. [PMID: 31330911 PMCID: PMC6681416 DOI: 10.3390/molecules24142644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/14/2019] [Accepted: 07/15/2019] [Indexed: 01/10/2023] Open
Abstract
A series of novel deoxycholic acid (DCA) derivatives containing aliphatic diamine and aminoalcohol or morpholine moieties at the C3 position were synthesized by 3,26-epoxide ring-opening reactions. These compounds were investigated for their cytotoxicity in four human tumor cell lines and murine macrophages and for inhibitory activity against macrophage-mediated NO synthesis in vitro. Obtained data revealed that: (i) all amine-containing substituents significantly increased the cytotoxicity of the novel compounds (IC502–10 = 1.0–36.0 μM) in comparison with DCA (IC50DCA ≥ 82.9 μM); (ii) aminoalcohol moieties were more preferable than diamine moieties due to the fact they imparted better selectivity for tumor cells of the novel derivatives; (iii) the susceptibility of tested cell lines to derivatives diminished in the following order: HuTu-80 (duodenal carcinoma) ≈ HepG2 (hepatocarcinoma) > KB-3-1 (cervical carcinoma) > RAW264.7 (macrophages) > A549 (lung carcinoma); (iv) compounds 8 and 9, bearing aminoethanol and aminopropanol moieties, respectively, exhibited high cytotoxic selectivity indexes (SIHuTu-80 = 7.9 and 8.3, respectively) and good drug-likeness parameters; (v) the novel compounds do not display anti-NO activity. Mechanistic study revealed that compound 9 induces ROS-dependent cell death by activation of intrinsic caspase-dependent apoptosis and cytodestructive autophagy in HuTu-80 cells and vitamin D receptor can be considered as its primary target.
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Barnes AC, Elowsky CG, Roston RL. An Arabidopsis protoplast isolation method reduces cytosolic acidification and activation of the chloroplast stress sensor SENSITIVE TO FREEZING 2. PLANT SIGNALING & BEHAVIOR 2019; 14:1629270. [PMID: 31189422 PMCID: PMC6768213 DOI: 10.1080/15592324.2019.1629270] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 06/03/2019] [Indexed: 05/20/2023]
Abstract
Chloroplasts adapt to freezing and other abiotic stresses in part by modifying their membranes. One key-remodeling enzyme is SENSITIVE TO FREEZING2 (SFR2). SFR2 is unusual because it does not respond to initial cold stress or cold acclimation, instead it responds during freezing conditions in Arabidopsis. This response has been shown to be sensitive to cytosolic acidification. The unique lipid products of SFR2 have also been detected in response to non-freezing stresses, but what causes SFR2 to respond in these stresses is unknown. Here, we investigate protoplast isolation as a representative of wounding stress. We show that SFR2 oligogalactolipid products accumulate during protoplast isolation. Notably, we show that protoplast cytosol is acidified during isolation. Modification of the buffers reduces oligogalactolipid accumulation, while prolonged incubation in the isolated state increases it. We conclude that SFR2 activation during protoplast isolation correlates with cytosolic acidification, implying that all SFR2 activation may be dependent on cytosolic acidification. We also conclude that protoplasts can be more gently isolated, reducing their stress.
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Affiliation(s)
- Allison C. Barnes
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Christian G. Elowsky
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Rebecca L. Roston
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, USA
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Soberanes-Gutiérrez CV, Vázquez-Carrada M, López-Villegas EO, Vega-Arreguín JC, Villa-Tanaca L, Ruiz-Herrera J. Autophagosomes accumulation in the vacuoles of the fungus Ustilago maydis and the role of proteases in their digestion. FEMS Microbiol Lett 2019; 366:5513442. [DOI: 10.1093/femsle/fnz108] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 06/06/2019] [Indexed: 01/08/2023] Open
Affiliation(s)
- Cinthia V Soberanes-Gutiérrez
- Laboratorio de Ciencias Agrogenómicas, de la Escuela Nacional de Estudios Superiores Unidad León, Universidad Nacional Autónoma de México. 37684, León Guanajuato, México
| | - Melissa Vázquez-Carrada
- Departamento de Microbiología de la Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional. 11340, Ciudad de México, México
| | - Edgar O López-Villegas
- Departamento de Microbiología de la Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional. 11340, Ciudad de México, México
| | - Julio C Vega-Arreguín
- Laboratorio de Ciencias Agrogenómicas, de la Escuela Nacional de Estudios Superiores Unidad León, Universidad Nacional Autónoma de México. 37684, León Guanajuato, México
| | - Lourdes Villa-Tanaca
- Departamento de Microbiología de la Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional. 11340, Ciudad de México, México
| | - José Ruiz-Herrera
- Departamento de Ingeniería Genética del Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Unidad Irapuato. 36821, Irapuato Guanajuato, México
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