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Xiong H, Lu D, Li Z, Wu J, Ning X, Lin W, Bai Z, Zheng C, Sun Y, Chi W, Zhang L, Xu X. The DELLA-ABI4-HY5 module integrates light and gibberellin signals to regulate hypocotyl elongation. PLANT COMMUNICATIONS 2023; 4:100597. [PMID: 37002603 PMCID: PMC10504559 DOI: 10.1016/j.xplc.2023.100597] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 03/21/2023] [Accepted: 03/28/2023] [Indexed: 05/29/2023]
Abstract
Plant growth is coordinately controlled by various environmental and hormonal signals, of which light and gibberellin (GA) signals are two critical factors with opposite effects on hypocotyl elongation. Although interactions between the light and GA signaling pathways have been studied extensively, the detailed regulatory mechanism of their direct crosstalk in hypocotyl elongation remains to be fully clarified. Previously, we reported that ABA INSENSITIVE 4 (ABI4) controls hypocotyl elongation through its regulation of cell-elongation-related genes, but whether it is also involved in GA signaling to promote hypocotyl elongation is unknown. In this study, we show that promotion of hypocotyl elongation by GA is dependent on ABI4 activation. DELLAs interact directly with ABI4 and inhibit its DNA-binding activity. In turn, ABI4 combined with ELONGATED HYPOCOTYL 5 (HY5), a key positive factor in light signaling, feedback regulates the expression of the GA2ox GA catabolism genes and thus modulates GA levels. Taken together, our results suggest that the DELLA-ABI4-HY5 module may serve as a molecular link that integrates GA and light signals to control hypocotyl elongation.
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Affiliation(s)
- Haibo Xiong
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Jinming Avenue, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China; Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing 100093, China
| | - Dandan Lu
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Jinming Avenue, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China
| | - Zhiyuan Li
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Jinming Avenue, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China; Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing 100093, China
| | - Jianghao Wu
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Jinming Avenue, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China
| | - Xin Ning
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Jinming Avenue, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China; Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing 100093, China
| | - Weijun Lin
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Jinming Avenue, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China; Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing 100093, China
| | - Zechen Bai
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Canhui Zheng
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Jinming Avenue, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China
| | - Yang Sun
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Jinming Avenue, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China
| | - Wei Chi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing 100093, China
| | - Lixin Zhang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Jinming Avenue, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China
| | - Xiumei Xu
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Jinming Avenue, Kaifeng 475004, China; Sanya Institute of Henan University, Sanya 572025, China.
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Razzaq MK, Rani R, Xing G, Xu Y, Raza G, Aleem M, Iqbal S, Arif M, Mukhtar Z, Nguyen HT, Varshney RK, Siddique KHM, Gai J. Genome-Wide Identification and Analysis of the Hsp40/J-Protein Family Reveals Its Role in Soybean ( Glycine max) Growth and Development. Genes (Basel) 2023; 14:1254. [PMID: 37372434 DOI: 10.3390/genes14061254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
The J-protein family comprises molecular chaperones involved in plant growth, development, and stress responses. Little is known about this gene family in soybean. Hence, we characterized J-protein genes in soybean, with the most highly expressed and responsive during flower and seed development. We also revealed their phylogeny, structure, motif analysis, chromosome location, and expression. Based on their evolutionary links, we divided the 111 potential soybean J-proteins into 12 main clades (I-XII). Gene-structure estimation revealed that each clade had an exon-intron structure resembling or comparable to others. Most soybean J-protein genes lacked introns in Clades I, III, and XII. Moreover, transcriptome data obtained from a publicly accessible soybean database and RT-qPCR were used to examine the differential expression of DnaJ genes in various soybean tissues and organs. The expression level of DnaJ genes indicated that, among 14 tissues, at least one tissue expressed the 91 soybean genes. The findings suggest that J-protein genes could be involved in the soybean growth period and offer a baseline for further functional research into J-proteins' role in soybean. One important application is the identification of J-proteins that are highly expressed and responsive during flower and seed development in soybean. These genes likely play crucial roles in these processes, and their identification can contribute to breeding programs to improve soybean yield and quality.
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Affiliation(s)
- Muhammad Khuram Razzaq
- Soybean Research Institute, MARA National Center for Soybean Improvement, MARA Key Laboratory of Biology and Genetic Improvement of Soybean, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Reena Rani
- National Institute for Biotechnology and Genetic Engineering, Faisalabad 38000, Pakistan
| | - Guangnan Xing
- Soybean Research Institute, MARA National Center for Soybean Improvement, MARA Key Laboratory of Biology and Genetic Improvement of Soybean, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Yufei Xu
- Soybean Research Institute, MARA National Center for Soybean Improvement, MARA Key Laboratory of Biology and Genetic Improvement of Soybean, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Ghulam Raza
- National Institute for Biotechnology and Genetic Engineering, Faisalabad 38000, Pakistan
| | - Muqadas Aleem
- Center for Advanced Studies in Agriculture and Food Security (CAS-AFS), University of Agriculture, Faisalabad 38040, Pakistan
| | - Shahid Iqbal
- Horticultural Science Department, North Florida Research and Education Center, University of Florida/IFAS, Quincy, FL 32351, USA
| | - Muhammad Arif
- National Institute for Biotechnology and Genetic Engineering, Faisalabad 38000, Pakistan
| | - Zahid Mukhtar
- National Institute for Biotechnology and Genetic Engineering, Faisalabad 38000, Pakistan
| | - Henry T Nguyen
- Division of Plant Sciences and National Center for Soybean Biotechnology, University of Missouri-Columbia, Columbia, MO 65211, USA
| | - Rajeev K Varshney
- Centre for Crop & Food Innovation, State Agricultural Biotechnology Centre, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia
| | - Kadambot H M Siddique
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6001, Australia
| | - Junyi Gai
- Soybean Research Institute, MARA National Center for Soybean Improvement, MARA Key Laboratory of Biology and Genetic Improvement of Soybean, National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
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Phytochrome A in plants comprises two structurally and functionally distinct populations — water-soluble phyA′ and amphiphilic phyA″. Biophys Rev 2022; 14:905-921. [DOI: 10.1007/s12551-022-00974-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 06/14/2022] [Indexed: 10/17/2022] Open
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Verma AK, Tamadaddi C, Tak Y, Lal SS, Cole SJ, Hines JK, Sahi C. The expanding world of plant J-domain proteins. CRITICAL REVIEWS IN PLANT SCIENCES 2019; 38:382-400. [PMID: 33223602 PMCID: PMC7678915 DOI: 10.1080/07352689.2019.1693716] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Plants maintain cellular proteostasis during different phases of growth and development despite a barrage of biotic and abiotic stressors in an ever-changing environment. This requires a collaborative effort of a cadre of molecular chaperones. Hsp70s and their obligate co-chaperones, J-domain proteins (JDPs), are arguably the most ubiquitous and formidable components of the cellular chaperone network, facilitating numerous and diverse cellular processes and allowing survival under a plethora of stressful conditions. JDPs are also among the most versatile chaperones. Compared to Hsp70s, the number of JDP-encoding genes has proliferated, suggesting the emergence of highly complex Hsp70-JDP networks, particularly in plants. Recent studies indicate that besides the increase in the number of JDP encoding genes; regulatory differences, neo- and sub-functionalization, and inter- and intra-class combinatorial interactions, is rapidly expanding the repertoire of Hsp70-JDP systems. This results in highly robust and functionally diverse chaperone networks in plants. Here, we review the current status of plant JDP research and discuss how the paradigm shift in the field can be exploited toward a better understanding of JDP function and evolution.
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Affiliation(s)
- Amit K. Verma
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Chetana Tamadaddi
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Yogesh Tak
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Silviya S. Lal
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | - Sierra J. Cole
- Department of Chemistry, Lafayette College, Easton, PA, USA
| | | | - Chandan Sahi
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
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Zhang B, Qiu HL, Qu DH, Ruan Y, Chen DH. Phylogeny-dominant classification of J-proteins in Arabidopsis thaliana and Brassica oleracea. Genome 2018; 61:405-415. [PMID: 29620479 DOI: 10.1139/gen-2017-0206] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hsp40s or DnaJ/J-proteins are evolutionarily conserved in all organisms as co-chaperones of molecular chaperone HSP70s that mainly participate in maintaining cellular protein homeostasis, such as protein folding, assembly, stabilization, and translocation under normal conditions as well as refolding and degradation under environmental stresses. It has been reported that Arabidopsis J-proteins are classified into four classes (types A-D) according to domain organization, but their phylogenetic relationships are unknown. Here, we identified 129 J-proteins in the world-wide popular vegetable Brassica oleracea, a close relative of the model plant Arabidopsis, and also revised the information of Arabidopsis J-proteins based on the latest online bioresources. According to phylogenetic analysis with domain organization and gene structure as references, the J-proteins from Arabidopsis and B. oleracea were classified into 15 main clades (I-XV) separated by a number of undefined small branches with remote relationship. Based on the number of members, they respectively belong to multigene clades, oligo-gene clades, and mono-gene clades. The J-protein genes from different clades may function together or separately to constitute a complicated regulatory network. This study provides a constructive viewpoint for J-protein classification and an informative platform for further functional dissection and resistant genes discovery related to genetic improvement of crop plants.
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Affiliation(s)
- Bin Zhang
- a Key Laboratory of Education, Department of Hunan Province on Plant Genetics and Molecular Biology, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Han-Lin Qiu
- b State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, Zhejiang 311300, China
| | - Dong-Hai Qu
- a Key Laboratory of Education, Department of Hunan Province on Plant Genetics and Molecular Biology, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Ying Ruan
- a Key Laboratory of Education, Department of Hunan Province on Plant Genetics and Molecular Biology, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Dong-Hong Chen
- b State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, Zhejiang 311300, China
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Sheerin DJ, Hiltbrunner A. Molecular mechanisms and ecological function of far-red light signalling. PLANT, CELL & ENVIRONMENT 2017; 40:2509-2529. [PMID: 28102581 DOI: 10.1111/pce.12915] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 05/18/2023]
Abstract
Land plants possess the ability to sense and respond to far-red light (700-760 nm), which serves as an important environmental cue. Due to the nature of far-red light, it is not absorbed by chlorophyll and thus is enriched in canopy shade and will also penetrate deeper into soil than other visible wavelengths. Far-red light responses include regulation of seed germination, suppression of hypocotyl growth, induction of flowering and accumulation of anthocyanins, which depend on one member of the phytochrome photoreceptor family, phytochrome A (phyA). Here, we review the current understanding of the underlying molecular mechanisms of how plants sense far-red light through phyA and the physiological responses to this light quality. Light-activated phytochromes act on two primary pathways within the nucleus; suppression of the E3 ubiquitin ligase complex CUL4/DDB1COP1/SPA and inactivation of the PHYTOCHROME INTERACTING FACTOR (PIF) family of bHLH transcription factors. These pathways integrate with other signal transduction pathways, including phytohormones, for tissue and developmental stage specific responses. Unlike other phytochromes that mediate red-light responses, phyA is transported from the cytoplasm to the nucleus in far-red light by the shuttle proteins FAR-RED ELONGATED HYPOCOTYL 1 (FHY1) and FHY1-LIKE (FHL). However, additional mechanisms must exist that shift the action of phyA to far-red light; current hypotheses are discussed.
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Affiliation(s)
- David J Sheerin
- Institute of Biology II, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Andreas Hiltbrunner
- Institute of Biology II, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany
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Lan X, Yang J, Cao M, Wang Y, Kawabata S, Li Y. Isolation and characterization of a J domain protein that interacts with ARC1 from ornamental kale (Brassica oleracea var. acephala). PLANT CELL REPORTS 2015; 34:817-29. [PMID: 25666275 DOI: 10.1007/s00299-015-1744-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 11/26/2014] [Accepted: 01/06/2015] [Indexed: 05/08/2023]
Abstract
A novel J domain protein, JDP1, was isolated from ornamental kale. The C-terminus of JDP1 specifically interacted with ARC1, which has a conserved role in self-incompatibility signaling. Armadillo (ARM)-repeat containing 1 (ARC1) plays a conserved role in self-incompatibility signaling across the Brassicaceae and functions downstream of the S-locus receptor kinase. Here, we identified a J domain protein 1 (JDP1) that interacts with ARC1 using a yeast two-hybrid screen against a stigma cDNA library from ornamental kale (Brassica oleracea var. acephala). JDP1, a 38.4-kDa protein with 344 amino acids, is a member of the Hsp40 family. Fragment JDP1(57-344), originally isolated from a yeast two-hybrid cDNA library, interacted specifically with ARC1 in yeast two-hybrid assays. The N-terminus of JDP1 (JDP1(1-68)) contains a J domain, and the C-terminus of JDP1 (JDP1(69-344)) contains an X domain of unknown function. However, JDP1(69-344) was required and sufficient for interaction with ARC1 in yeast two-hybrid assays and in vitro binding assays. Moreover, JDP1(69-344) regulated the trafficking of ARC1 from the cytoplasm to the plasma membrane by interacting with ARC1 in Arabidopsis mesophyll protoplasts. Finally, Tyr(8) in the JDP1 N-terminal region was identified to be the specific site for regulating the interaction between JDP1 and BoARC1 in yeast two-hybrid assays. Possible roles of JDP1 as an interactor with ARC1 in Brassica are discussed.
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Affiliation(s)
- Xingguo Lan
- College of Life Sciences, Northeast Forestry University, Harbin, 150040, Heilongjiang Province, China
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Wang X, Jia N, Zhao C, Fang Y, Lv T, Zhou W, Sun Y, Li B. Knockout of AtDjB1, a J-domain protein from Arabidopsis thaliana, alters plant responses to osmotic stress and abscisic acid. PHYSIOLOGIA PLANTARUM 2014; 152:286-300. [PMID: 24521401 DOI: 10.1111/ppl.12169] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 01/18/2014] [Accepted: 01/21/2014] [Indexed: 05/26/2023]
Abstract
AtDjB1 is a member of the Arabidopsis thaliana J-protein family. AtDjB1 is targeted to the mitochondria and plays a crucial role in A. thaliana heat and oxidative stress resistance. Herein, the role of AtDjB1 in adapting to saline and drought stress was studied in A. thaliana. AtDjB1 expression was induced through salinity, dehydration and abscisic acid (ABA) in young seedlings. Reverse genetic analyses indicate that AtDjB1 is a negative regulator in plant osmotic stress tolerance. Further, AtDjB1 knockout mutant plants (atj1-1) exhibited greater ABA sensitivity compared with the wild-type (WT) plants and the mutant lines with a rescued AtDjB1 gene. AtDjB1 gene knockout also altered the expression of several ABA-responsive genes, which suggests that AtDjB1 is involved in osmotic stress tolerance through its effects on ABA signaling pathways. Moreover, atj1-1 plants exhibited higher glucose levels and greater glucose sensitivity in the post-germination development stage. Applying glucose promoted an ABA response in seedlings, and the promotion was more evident in atj1-1 than WT seedlings. Taken together, higher glucose levels in atj1-1 plants are likely responsible for the greater ABA sensitivity and increased osmotic stress tolerance.
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Affiliation(s)
- Xingxing Wang
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang, 050024, PR China
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Xia Z, Zhang X, Li J, Su X, Liu J. Overexpression of a tobacco J-domain protein enhances drought tolerance in transgenic Arabidopsis. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 83:100-6. [PMID: 25128645 DOI: 10.1016/j.plaphy.2014.07.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Accepted: 07/27/2014] [Indexed: 05/05/2023]
Abstract
DnaJ proteins constitute a DnaJ/Hsp40 family and are important regulators involved in diverse cellular functions. To date, the molecular mechanisms of DnaJ proteins involved in response to drought stress in plants are largely unknown. In this study, a putative DnaJ ortholog from Nicotiana tabacum (NtDnaJ1), which encodes a putative type-I J-protein, was isolated. The transcript levels of NtDnaJ1 were higher in aerial tissues and were markedly up-regulated by drought stress. Over-expression of NtDnaJ1 in Arabidopsis plants enhanced their tolerance to osmotic or drought stress. Quantitative determination of H2O2 accumulation has shown that H2O2 content increased in wild-type and transgenic seedlings under osmotic stress, but was significantly lower in both transgenic lines compared with the wild-type. Expression analysis of stress-responsive genes in NtDnaJ1-transgenic Arabidopsis revealed that there was significantly increased expression of genes involved in the ABA-dependent signaling pathway (AtRD20, AtRD22 and AtAREB2) and antioxidant genes (AtSOD1, AtSOD2, and AtCAT1). Collectively, these data demonstrate that NtDnaJ1 could be involved in drought stress response and its over-expression enhances drought tolerance possibly through regulating expression of stress-responsive genes. This study may facilitate our understandings of the biological roles of DnaJ protein-mediated abiotic stress in higher plants and accelerate genetic improvement of crop plants tolerant to environmental stresses.
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Affiliation(s)
- Zongliang Xia
- Henan Agricultural University, Zhengzhou 450002, PR China.
| | - Xiaoquan Zhang
- Henan Agricultural University, Zhengzhou 450002, PR China
| | - Junqi Li
- Henan Agricultural University, Zhengzhou 450002, PR China
| | - Xinhong Su
- Henan Tobacco Company, Zhengzhou 450008, PR China
| | - Jianjun Liu
- Zhengzhou Branch, Henan Tobacco Company, Zhengzhou 450001, PR China
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Ioakeimidis F, Ott C, Kozjak-Pavlovic V, Violitzi F, Rinotas V, Makrinou E, Eliopoulos E, Fasseas C, Kollias G, Douni E. A splicing mutation in the novel mitochondrial protein DNAJC11 causes motor neuron pathology associated with cristae disorganization, and lymphoid abnormalities in mice. PLoS One 2014; 9:e104237. [PMID: 25111180 PMCID: PMC4128653 DOI: 10.1371/journal.pone.0104237] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 07/09/2014] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial structure and function is emerging as a major contributor to neuromuscular disease, highlighting the need for the complete elucidation of the underlying molecular and pathophysiological mechanisms. Following a forward genetics approach with N-ethyl-N-nitrosourea (ENU)-mediated random mutagenesis, we identified a novel mouse model of autosomal recessive neuromuscular disease caused by a splice-site hypomorphic mutation in a novel gene of unknown function, DnaJC11. Recent findings have demonstrated that DNAJC11 protein co-immunoprecipitates with proteins of the mitochondrial contact site (MICOS) complex involved in the formation of mitochondrial cristae and cristae junctions. Homozygous mutant mice developed locomotion defects, muscle weakness, spasticity, limb tremor, leucopenia, thymic and splenic hypoplasia, general wasting and early lethality. Neuropathological analysis showed severe vacuolation of the motor neurons in the spinal cord, originating from dilatations of the endoplasmic reticulum and notably from mitochondria that had lost their proper inner membrane organization. The causal role of the identified mutation in DnaJC11 was verified in rescue experiments by overexpressing the human ortholog. The full length 63 kDa isoform of human DNAJC11 was shown to localize in the periphery of the mitochondrial outer membrane whereas putative additional isoforms displayed differential submitochondrial localization. Moreover, we showed that DNAJC11 is assembled in a high molecular weight complex, similarly to mitofilin and that downregulation of mitofilin or SAM50 affected the levels of DNAJC11 in HeLa cells. Our findings provide the first mouse mutant for a putative MICOS protein and establish a link between DNAJC11 and neuromuscular diseases.
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Affiliation(s)
- Fotis Ioakeimidis
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
- Division of Immunology, Biomedical Sciences Research Center “Alexander Fleming”, Vari, Greece
| | - Christine Ott
- Department of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Vera Kozjak-Pavlovic
- Department of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Foteini Violitzi
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
- Division of Immunology, Biomedical Sciences Research Center “Alexander Fleming”, Vari, Greece
| | - Vagelis Rinotas
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
- Division of Immunology, Biomedical Sciences Research Center “Alexander Fleming”, Vari, Greece
| | - Eleni Makrinou
- Division of Immunology, Biomedical Sciences Research Center “Alexander Fleming”, Vari, Greece
| | - Elias Eliopoulos
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Costas Fasseas
- Department of Crop Science, Agricultural University of Athens, Athens, Greece
| | - George Kollias
- Division of Immunology, Biomedical Sciences Research Center “Alexander Fleming”, Vari, Greece
| | - Eleni Douni
- Department of Biotechnology, Agricultural University of Athens, Athens, Greece
- Division of Immunology, Biomedical Sciences Research Center “Alexander Fleming”, Vari, Greece
- * E-mail:
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So HA, Chung E, Lee JH. Arabidopsis atDjC53 encoding a type III J-protein plays a negative role in heat shock tolerance. Genes Genomics 2014. [DOI: 10.1007/s13258-014-0207-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Casal JJ, Candia AN, Sellaro R. Light perception and signalling by phytochrome A. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2835-45. [PMID: 24220656 DOI: 10.1093/jxb/ert379] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In etiolated seedlings, phytochrome A (phyA) mediates very-low-fluence responses (VLFRs), which initiate de-etiolation at the interphase between the soil and above-ground environments, and high-irradiance responses (HIR), which complete de-etiolation under dense canopies and require more sustained activation with far-red light. Light-activated phyA is transported to the nucleus by FAR-RED ELONGATED HYPOCOTYL1 (FHY1). The nuclear pool of active phyA increases under prolonged far-red light of relatively high fluence rates. This condition maximizes the rate of FHY1-phyA complex assembly and disassembly, allowing FHY1 to return to the cytoplasm to translocate further phyA to the nucleus, to replace phyA degraded in the proteasome. The core signalling pathways downstream of nuclear phyA involve the negative regulation of CONSTITUTIVE PHOTOMORPHOGENIC 1, which targets for degradation transcription factors required for photomorphogenesis, and PHYTOCHROME-INTERACTING FACTORs, which are transcription factors that repress photomorphogenesis. Under sustained far-red light activation, released FHY1 can also be recruited with active phyA to target gene promoters as a transcriptional activator, and nuclear phyA signalling activates a positive regulatory loop involving BELL-LIKE HOMEODOMAIN 1 that reinforces the HIR.
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Affiliation(s)
- J J Casal
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires and CONICET, 1417 Buenos Aires, Argentina Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires-CONICET, C1405BWE Buenos Aires, Argentina
| | - A N Candia
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires and CONICET, 1417 Buenos Aires, Argentina
| | - R Sellaro
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires and CONICET, 1417 Buenos Aires, Argentina
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Kong F, Deng Y, Wang G, Wang J, Liang X, Meng Q. LeCDJ1, a chloroplast DnaJ protein, facilitates heat tolerance in transgenic tomatoes. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2014; 56:63-74. [PMID: 24148796 DOI: 10.1111/jipb.12119] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/15/2013] [Indexed: 05/22/2023]
Abstract
The roles of a tomato (Lycopersicon esculentum) chloroplast-targeted DnaJ protein (LeCDJ1) were investigated using wild-type (WT) and sense transgenic tomatoes. The LeCDJ1 expression was upregulated by 38 °C, 42 °C, 45 °C, NaCl, PEG, methyl viologen (MV) and hydrogen peroxide (H2O2), but not by 30 °C and 35 °C. Meanwhile, LeCDJ1 was involved in the response of plants to abscisic acid (ABA). Under heat stress, the sense plants showed better growth, higher chlorophyll content, lower malondialdehyde (MDA) accumulation and relative electrical conductivity (REC), and also less PSII photoinhibition than WT. Interestingly, the sense plants treated with streptomycin (SM), an inhibitor of organellar translation, still showed higher maximum photochemistry efficiency of PSII (Fv/Fm) and D1 protein levels than the SM-untreated WT, suggesting that the protective effect of LeCDJ1 on PSII was, at least partially, independent of D1 protein synthesis. Furthermore, the relatively lower superoxide radical (O2(•-)) and H2O2 levels in the sense plants were considered to be due to the higher ascorbate peroxidase (APX) and superoxide dismutase (SOD) activity, which seemed unlikely dependent on their transcription level. These results indicated that LeCDJ1 overexpression facilitated heat tolerance in transgenic tomatoes.
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Affiliation(s)
- Fanying Kong
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, 271018, China
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14
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Wu FQ, Fan CM, Zhang XM, Fu YF. The phytochrome gene family in soybean and a dominant negative effect of a soybean PHYA transgene on endogenous Arabidopsis PHYA. PLANT CELL REPORTS 2013; 32:1879-90. [PMID: 24013793 DOI: 10.1007/s00299-013-1500-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Revised: 08/18/2013] [Accepted: 08/26/2013] [Indexed: 06/02/2023]
Abstract
KEY MESSAGE The evolutionary origin of the phytochrome genes in soybean was analyzed. The expression profiles of PHYA paralogs were characterized. The heterologous expression of GmPHYA1 in Arabidopsis resulted in longer hypocotyls. The phytochromes (PHY) are a small family of red/far-red light photoreceptors which regulate a number of important developmental responses in plants. So far, the members of the PHY gene family in soybean (Glycine max) remain unclear and an understanding of each member's physiological functions is limited. Our present in silico analysis revealed that the soybean genome harbors four PHYA, two PHYB and two PHYE, totally four pairs of eight PHY loci. The phylogenetic analysis suggested that the four PHY paralogous pairs originated from the latest round of genome duplication (~13 million years ago) and the four copies of PHYA were remnants of the two rounds of genome duplication (~58 and ~13 million years ago). A possible evolutionary history of PHYA homologs in the three legume species (soybean, Medicago truncatula, and Lotus japonicus) was proposed and the fate of duplicate soybean PHYA genes following polyploidization was discussed. The expression profiles of a soybean PHYA paralogous pair (GmPHYA1 and GmPHYA2) showed that the transcript abundance was highest in the aerial organs of young plants. The physiological role of GmPHYA1 was explored by observing the de-etiolation phenotype of transgenic Arabidopsis plants constitutively expressing GmPHYA1. The GmPHYA1 protein interfered with the function of endogenous PHYA with respect to de-etiolation in a dominant negative manner when exogenously expressed in Arabidopsis. The elucidation of the PHY gene family members in soybean provide us with a general description and understanding of the photoreceptor gene family in this important crop plant.
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Affiliation(s)
- Fa-Qiang Wu
- MOA Key Lab of Soybean Biology (Beijing), National Key Facility of Crop Gene Resource and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, 12 Zhongguancun Nandajie, Haidian District, Beijing, 100081, China
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15
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Shi H, Zhong S, Mo X, Liu N, Nezames CD, Deng XW. HFR1 sequesters PIF1 to govern the transcriptional network underlying light-initiated seed germination in Arabidopsis. THE PLANT CELL 2013; 25:3770-84. [PMID: 24179122 PMCID: PMC3877798 DOI: 10.1105/tpc.113.117424] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 09/30/2013] [Accepted: 10/14/2013] [Indexed: 05/19/2023]
Abstract
Seed germination is the first step for seed plants to initiate a new life cycle. Light plays a predominant role in promoting seed germination, where the initial phase is mediated by photoreceptor phytochrome B (phyB). Previous studies showed that phytochrome-interacting factor1 (PIF1) represses seed germination downstream of phyB. Here, we identify a positive regulator of phyB-dependent seed germination, long hypocotyl in far-red1 (HFR1). HFR1 blocks PIF1 transcriptional activity by forming a heterodimer with PIF1 that prevents PIF1 from binding to DNA. Our whole-genomic analysis shows that HFR1 and PIF1 oppositely mediate the light-regulated transcriptome in imbibed seeds. Through the HFR1-PIF1 module, light regulates expression of numerous genes involved in cell wall loosening, cell division, and hormone pathways to initiate seed germination. The functionally antagonistic HFR1-PIF1 pair constructs a fail-safe mechanism for fine-tuning seed germination during low-level illumination, ensuring a rapid response to favorable environmental changes. This study identifies the HFR1-PIF1 pair as a central module directing the whole genomic transcriptional network to rapidly initiate light-induced seed germination.
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Affiliation(s)
- Hui Shi
- Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, College of Life Sciences, Peking University, Beijing 100871, China
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | - Shangwei Zhong
- Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, College of Life Sciences, Peking University, Beijing 100871, China
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | - Xiaorong Mo
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | - Na Liu
- Yale Stem Cell Center and Department of Cell Biology, Yale School of Medicine, New Haven, Connecticut 06519
| | - Cynthia D. Nezames
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
| | - Xing Wang Deng
- Peking-Yale Joint Center for Plant Molecular Genetics and Agro-biotechnology, College of Life Sciences, Peking University, Beijing 100871, China
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
- Address correspondence to
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16
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Ibarra SE, Auge G, Sánchez RA, Botto JF. Transcriptional programs related to phytochrome A function in Arabidopsis seed germination. MOLECULAR PLANT 2013; 6:1261-73. [PMID: 23292879 DOI: 10.1093/mp/sst001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In Arabidopsis seeds, germination is promoted only by phytochromes, principally phytochrome B (phyB) and phytochrome A (phyA). Despite the abundant information concerning the molecular basis of phyB signaling downstream of PIF1/PIL5, the signaling network inducing germination by phyA is poorly known. Here, we describe the influence of phyA on the transcriptome of Arabidopsis seeds when germination is induced by a far-red (FR) pulse. The expression of 11% of the genome was significantly regulated by phyA. Most of the genes were up-regulated and the changes noted late (i.e. 5 h after a FR pulse), whereas changes in down-regulated genes were more abundant earlier (i.e. 0.5 h after a FR pulse). Auxin- and GA-associated elements were overrepresented in the genes that were modified by phyA. A significant number of genes whose expression was affected by phyA had not been previously reported to be dependent on PIL5. Among them, homozygotic mutant seeds of MYB66, a SAUR-like protein, PIN7, and GASA4 showed an impaired promotion of germination by phyA. Natural variation at the transcriptional level was found in early signaling and GA metabolic genes, but not in ABA metabolic and expansin genes between Columbia and Landsberg erecta accessions. Although phyA and phyB/PIL5 signaling pathways share some molecular components, our data suggest that phyA signaling is partially independent of PIL5 when germination is promoted by very low fluences of light.
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Affiliation(s)
- Silvia E Ibarra
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas, Av. San Martín 4453, C1417DSE, Ciudad de Buenos Aires, Argentina
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17
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Liu JZ, Whitham SA. Overexpression of a soybean nuclear localized type-III DnaJ domain-containing HSP40 reveals its roles in cell death and disease resistance. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 74:110-21. [PMID: 23289813 DOI: 10.1111/tpj.12108] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Revised: 12/18/2012] [Accepted: 12/20/2012] [Indexed: 05/19/2023]
Abstract
Heat-shock proteins such as HSP70 and HSP90 are important molecular chaperones that play critical roles in biotic and abiotic stress responses; however, the involvement of their co-chaperones in stress biology remains largely uninvestigated. In a screen for candidate genes stimulating cell death in Glycine max (soybean), we transiently overexpressed full-length cDNAs of soybean genes that are highly induced during soybean rust infection in Nicotiana benthamiana leaves. Overexpression of a type-III DnaJ domain-containing HSP40 (GmHSP40.1), a co-chaperone of HSP70, caused hypersensitive response (HR)-like cell death. The HR-like cell death was dependent on MAPKKKα and WIPK, because silencing each of these genes suppressed the HR. Consistent with the presence of a nuclear localization signal (NLS) motif within the GmHSP40.1 coding sequence, GFP-GmHSP40.1 was exclusively present in nuclear bodies or speckles. Nuclear localization of GmHSP40.1 was necessary for its function, because deletion of the NLS or addition of a nuclear export signal abolished its HR-inducing ability. GmHSP40.1 co-localized with HcRed-SE, a protein involved in pri-miRNA processing, which has been shown to be co-localized with SR33-YFP, a protein involved in pre-mRNA splicing, suggesting a possible role for GmHSP40.1 in mRNA splicing or miRNA processing, and a link between these processes and cell death. Silencing GmHSP40.1 enhanced the susceptibility of soybean plants to Soybean mosaic virus, confirming its positive role in pathogen defense. Together, the results demonstrate a critical role of a nuclear-localized DnaJ domain-containing GmHSP40.1 in cell death and disease resistance in soybean.
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Affiliation(s)
- Jian-Zhong Liu
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011, USA
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18
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So HA, Chung E, Lee JH. Molecular characterization of soybean GmDjp1 encoding a type III J-protein induced by abiotic stress. Genes Genomics 2013. [DOI: 10.1007/s13258-013-0078-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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19
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Zhou W, Zhou T, Li MX, Zhao CL, Jia N, Wang XX, Sun YZ, Li GL, Xu M, Zhou RG, Li B. The Arabidopsis J-protein AtDjB1 facilitates thermotolerance by protecting cells against heat-induced oxidative damage. THE NEW PHYTOLOGIST 2012; 194:364-378. [PMID: 22356282 DOI: 10.1111/j.1469-8137.2012.04070.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
AtDjB1 belongs to the J-protein family in Arabidopsis thaliana. Its biological functions in plants are largely unknown. In this study, we examined the roles of AtDjB1 in resisting heat and oxidative stresses in A. thaliana using reverse genetic analysis. AtDjB1 knockout plants (atj1-1) were more sensitive to heat stress than wildtype plants, and displayed decreased concentrations of ascorbate (ASC), and increased concentrations of hydrogen peroxide (H(2)O(2)) and oxidative products after heat shock. Application of H(2)O(2) accelerated cell death and decreased seedling viability in atj1-1. Exogenous ASC conferred much greater thermotolerance in atj1-1 than in wildtype plants, suggesting that a lower concentration of ASC in atj1-1 could be responsible for the increased concentration of H(2)O(2) and decreased thermotolerance. Furthermore, AtDjB1 was found to localize to mitochondria, directly interact with a mitochondrial heat-shock protein 70 (mtHSC70-1), and stimulate ATPase activity of mtHSC70-1. AtDjB1 knockout led to the accumulation of cellular ATP and decreased seedling respiration, indicating that AtDjB1 modulated the ASC concentration probably through affecting the function of mitochondria. Taken together, these results suggest that AtDjB1 plays a crucial role in maintaining redox homeostasis, and facilitates thermotolerance by protecting cells against heat-induced oxidative damage.
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Affiliation(s)
- Wei Zhou
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China
- Institute of Genetics and Physiology, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China
- College of Biology and Engineering, Hebei University of Economics and Business, Shijiazhuang 050061, China
| | - Ting Zhou
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Mi-Xin Li
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Chun-Lan Zhao
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Ning Jia
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Xing-Xing Wang
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Yong-Zhen Sun
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Guo-Liang Li
- Institute of Genetics and Physiology, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China
| | - Meng Xu
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Ren-Gang Zhou
- Institute of Genetics and Physiology, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China
| | - Bing Li
- Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China
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20
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Chen KM, Piippo M, Holmström M, Nurmi M, Pakula E, Suorsa M, Aro EM. A chloroplast-targeted DnaJ protein AtJ8 is negatively regulated by light and has rapid turnover in darkness. JOURNAL OF PLANT PHYSIOLOGY 2011; 168:1780-3. [PMID: 21592617 DOI: 10.1016/j.jplph.2011.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 04/12/2011] [Accepted: 04/12/2011] [Indexed: 05/20/2023]
Abstract
The DnaJ proteins (also called as J proteins, J domain proteins or HSP40 proteins) function as molecular co-chaperones for the HSP70 proteins. We assessed the expression of the small chloroplast-targeted DnaJ protein, the AtJ8 protein, by subjecting the wild type Arabidopsis plants to different illumination conditions. It is shown that the expression of the transcripts and proteins of the ATJ8 gene is primarily regulated at the level of transcription. When plants were incubated under high light for 3h, both the transcripts and proteins were completely abolished. Upon transfer of plants to darkness, the transcripts started rapidly accumulating, and subsequently, the AtJ8 protein became visible after 2h in darkness. Conversely, incubation of plants in darkness or under low light intensities induced expression of the ATJ8 transcripts and proteins. Feeding plants with sugars clearly decreased the transcript and protein levels, and incubation with cycloheximide revealed a rapid turnover for AtJ8 in darkness. Moreover, the AtJ8 protein was found to be nearly missing from the var1 mutant, which lacks the FTSH5 protease. It is concluded that AtJ8 is expressed mainly in darkness, is prone to a rapid turnover but is partially stabilized by the FTSH proteases.
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Affiliation(s)
- Kun-Ming Chen
- College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
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21
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Wolf I, Kircher S, Fejes E, Kozma-Bognár L, Schäfer E, Nagy F, Ádám É. Light-regulated nuclear import and degradation of Arabidopsis phytochrome-A N-terminal fragments. PLANT & CELL PHYSIOLOGY 2011; 52:361-72. [PMID: 21169346 PMCID: PMC3037077 DOI: 10.1093/pcp/pcq194] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 12/09/2010] [Indexed: 05/20/2023]
Abstract
The photoreceptor phytochrome-A (phyA) regulates germination and seedling establishment by mediating very low fluence (VLFR) and far-red high irradiance (FR-HIR) responses in Arabidopsis thaliana. In darkness, phyA homodimers exist in the biologically inactive Pr form and are localized in the cytoplasm. Light induces formation of the biologically active Pfr form and subsequent rapid nuclear import. PhyA Pfr, in contrast to the Pr form, is labile and has a half-life of ∼30 min. We produced transgenic plants in a phyA-201 null background that express the PHYA-yellow fluorescent protein (YFP) or the PHYA686-YFP-dimerization domain (DD) and PHYA686-YFP-DD-nuclear localization signal (NLS) or PHYA686-YFP-DD-nuclear exclusion signal (NES) fusion proteins. The PHYA686-YFP fusion proteins contained the N-terminal domain of phyA (686 amino acid residues), a short DD and the YFP. Here we report that (i) PHYA686-YFP-DD fusion protein is imported into the nucleus in a light-dependent fashion; (ii) neither of the PHYA686 fusion proteins is functional in FR-HIR and nuclear VLFR; and (iii) the phyA-dependent, blue light-induced inhibition of hypocotyl growth is mediated by the PHYA686-YFP-DD-NES but not by the PHYA686-YFP-DD-NLS and PHYA686-YFP-DD fusion proteins. We demonstrate that (i) light induces degradation of all PHYA N-terminal-containing fusion proteins and (ii) these N-terminal domain-containing fusion proteins including the constitutively nuclear PHYA686-YFP-DD-NLS and predominantly cytoplasmic PHYA686-YFP-DD-NES degrade at comparable rates but markedly more slowly than PHYA-YFP, whereas (iii) light-induced degradation of the native phyA is faster compared with PHYA-YFP.
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Affiliation(s)
- Iris Wolf
- Institute of Botany, Biology II, University of Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany
| | - Stefan Kircher
- Institute of Botany, Biology II, University of Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany
| | - Erzsébet Fejes
- Plant Biology Institute, Biological Research Centre, Temesvari krt. 62, H-6726 Szeged, Hungary
| | - László Kozma-Bognár
- Plant Biology Institute, Biological Research Centre, Temesvari krt. 62, H-6726 Szeged, Hungary
| | - Eberhard Schäfer
- Institute of Botany, Biology II, University of Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany
| | - Ferenc Nagy
- Plant Biology Institute, Biological Research Centre, Temesvari krt. 62, H-6726 Szeged, Hungary
- School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JH, UK
| | - Éva Ádám
- Plant Biology Institute, Biological Research Centre, Temesvari krt. 62, H-6726 Szeged, Hungary
- *Corresponding author: E-mail, ; Fax, +36-62-433-434
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Shen L, Kang YGG, Liu L, Yu H. The J-domain protein J3 mediates the integration of flowering signals in Arabidopsis. THE PLANT CELL 2011; 23:499-514. [PMID: 21343416 PMCID: PMC3077791 DOI: 10.1105/tpc.111.083048] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 01/07/2011] [Accepted: 02/08/2011] [Indexed: 05/18/2023]
Abstract
The timing of the switch from vegetative to reproductive development in Arabidopsis thaliana is controlled by an intricate network of flowering pathways, which converge on the transcriptional regulation of two floral pathway integrators, FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1). SHORT VEGETATIVE PHASE (SVP) acts as a key flowering regulator that represses the expression of FT and SOC1. Here, we report the identification of another potent flowering promoter, Arabidopsis DNAJ HOMOLOG 3 (J3), which mediates the integration of flowering signals through its interaction with SVP. J3 encodes a type I J-domain protein and is ubiquitously expressed in various plant tissues. J3 expression is regulated by multiple flowering pathways. Loss of function of J3 results in a significant late-flowering phenotype, which is partly due to decreased expression of SOC1 and FT. We further show that J3 interacts directly with SVP in the nucleus and prevents in vivo SVP binding to SOC1 and FT regulatory sequences. Our results suggest a flowering mechanism by which J3 integrates flowering signals from several genetic pathways and acts as a transcriptional regulator to upregulate SOC1 and FT through directly attenuating SVP binding to their regulatory sequences during the floral transition.
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Affiliation(s)
| | | | | | - Hao Yu
- Address correspondence to
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Kami C, Lorrain S, Hornitschek P, Fankhauser C. Light-regulated plant growth and development. Curr Top Dev Biol 2010; 91:29-66. [PMID: 20705178 DOI: 10.1016/s0070-2153(10)91002-8] [Citation(s) in RCA: 428] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Plants are sessile and photo-autotrophic; their entire life cycle is thus strongly influenced by the ever-changing light environment. In order to sense and respond to those fluctuating conditions higher plants possess several families of photoreceptors that can monitor light from UV-B to the near infrared (far-red). The molecular nature of UV-B sensors remains unknown, red (R) and far-red (FR) light is sensed by the phytochromes (phyA-phyE in Arabidopsis) while three classes of UV-A/blue photoreceptors have been identified: cryptochromes, phototropins, and members of the Zeitlupe family (cry1, cry2, phot1, phot2, ZTL, FKF1, and LKP2 in Arabidopsis). Functional specialization within photoreceptor families gave rise to members optimized for a wide range of light intensities. Genetic and photobiological studies performed in Arabidopsis have shown that these light sensors mediate numerous adaptive responses (e.g., phototropism and shade avoidance) and developmental transitions (e.g., germination and flowering). Some physiological responses are specifically triggered by a single photoreceptor but in many cases multiple light sensors ensure a coordinated response. Recent studies also provide examples of crosstalk between the responses of Arabidopsis to different external factors, in particular among light, temperature, and pathogens. Although the different photoreceptors are unrelated in structure, in many cases they trigger similar signaling mechanisms including light-regulated protein-protein interactions or light-regulated stability of several transcription factors. The breath and complexity of this topic forced us to concentrate on specific aspects of photomorphogenesis and we point the readers to recent reviews for some aspects of light-mediated signaling (e.g., transition to flowering).
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Affiliation(s)
- Chitose Kami
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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24
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Hofmann NR. OWL1 is a phytochrome a signaling component dedicated to the very low fluence response. THE PLANT CELL 2009; 21:2985. [PMID: 19808945 PMCID: PMC2782273 DOI: 10.1105/tpc.109.211010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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