1
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Che R, Liu Y, Yan S, Yang C, Sun Y, Liu C, Ma F. Elongation factor MdEF-Tu coordinates with heat shock protein MdHsp70 to enhance apple thermotolerance. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 117:1250-1263. [PMID: 37991990 DOI: 10.1111/tpj.16561] [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: 05/13/2023] [Revised: 10/08/2023] [Accepted: 11/13/2023] [Indexed: 11/24/2023]
Abstract
High-temperature stress results in protein misfolding/unfolding and subsequently promotes the accumulation of cytotoxic protein aggregates that can compromise cell survival. Heat shock proteins (HSPs) function as molecular chaperones that coordinate the refolding and degradation of aggregated proteins to mitigate the detrimental effects of high temperatures. However, the relationship between HSPs and protein aggregates in apples under high temperatures remains unclear. Here, we show that an apple (Malus domestica) chloroplast-localized, heat-sensitive elongation factor Tu (MdEF-Tu), positively regulates apple thermotolerance when it is overexpressed. Transgenic apple plants exhibited higher photosynthetic capacity and better integrity of chloroplasts during heat stress. Under high temperatures, MdEF-Tu formed insoluble aggregates accompanied by ubiquitination modifications. Furthermore, we identified a chaperone heat shock protein (MdHsp70), as an interacting protein of MdEF-Tu. Moreover, we observed obviously elevated MdHsp70 levels in 35S: MdEF-Tu apple plants that prevented the accumulation of ubiquitinated MdEF-Tu aggregates, which positively contributes to the thermotolerance of the transgenic plants. Overall, our results provide new insights into the molecular chaperone function of MdHsp70, which mediates the homeostasis of thermosensitive proteins under high temperatures.
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Affiliation(s)
- Runmin Che
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yuerong Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Shengqi Yan
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chao Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yubo Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Changhai Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, 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, Shaanxi, 712100, China
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2
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Sun M, Shen Y. Integrating the multiple functions of CHLH into chloroplast-derived signaling fundamental to plant development and adaptation as well as fruit ripening. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 338:111892. [PMID: 37821024 DOI: 10.1016/j.plantsci.2023.111892] [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: 04/12/2023] [Revised: 10/01/2023] [Accepted: 10/06/2023] [Indexed: 10/13/2023]
Abstract
Chlorophyll (Chl)-mediated oxygenic photosynthesis sustains life on Earth. Greening leaves play fundamental roles in plant growth and crop yield, correlating with the idea that more Chls lead to better adaptation. However, they face significant challenges from various unfavorable environments. Chl biosynthesis hinges on the first committed step, which involves inserting Mg2+ into protoporphyrin. This step is facilitated by the H subunit of magnesium chelatase (CHLH) and features a conserved mechanism from cyanobacteria to plants. For better adaptation to fluctuating land environments, especially drought, CHLH evolves multiple biological functions, including Chl biosynthesis, retrograde signaling, and abscisic acid (ABA) responses. Additionally, it integrates into various chloroplast-derived signaling pathways, encompassing both retrograde signaling and hormonal signaling. The former comprises ROS (reactive oxygen species), heme, GUN (genomes uncoupled), MEcPP (methylerythritol cyclodiphosphate), β-CC (β-cyclocitral), and PAP (3'-phosphoadenosine-5'-phosphate). The latter involves phytohormones like ABA, ethylene, auxin, cytokinin, gibberellin, strigolactone, brassinolide, salicylic acid, and jasmonic acid. Together, these elements create a coordinated regulatory network tailored to plant development and adaptation. An intriguing example is how drought-mediated improvement of fruit quality provides insights into chloroplast-derived signaling, aiding the shift from vegetative to reproductive growth. In this context, we explore the integration of CHLH's multifaceted roles into chloroplast-derived signaling, which lays the foundation for plant development and adaptation, as well as fruit ripening and quality. In the future, manipulating chloroplast-derived signaling may offer a promising avenue to enhance crop yield and quality through the homeostasis, function, and regulation of Chls.
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Affiliation(s)
- Mimi Sun
- College of Horticulture, China Agricultural University, Beijing 100193, China; College of Plant Science and Technology, Beijing University of Agriculture, 7 Beinong Road, Changping District, Beijing 102206, China
| | - Yuanyue Shen
- College of Plant Science and Technology, Beijing University of Agriculture, 7 Beinong Road, Changping District, Beijing 102206, China.
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3
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Zhang Z, Li D, Xie R, Guo R, Nair S, Han H, Zhang G, Zhao Q, Zhang L, Jiao N, Zhang Y. Plastoquinone synthesis inhibition by tetrabromo biphenyldiol as a widespread algicidal mechanism of marine bacteria. THE ISME JOURNAL 2023; 17:1979-1992. [PMID: 37679430 PMCID: PMC10579414 DOI: 10.1038/s41396-023-01510-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/30/2023] [Accepted: 09/01/2023] [Indexed: 09/09/2023]
Abstract
Algae and bacteria have complex and intimate interactions in the ocean. Besides mutualism, bacteria have evolved a variety of molecular-based anti-algal strategies. However, limited by the unknown mechanism of synthesis and action of these molecules, these strategies and their global prevalence remain unknown. Here we identify a novel strategy through which a marine representative of the Gammaproteobacteria produced 3,3',5,5'-tetrabromo-2,2'-biphenyldiol (4-BP), that kills or inhibits diverse phytoplankton by inhibiting plastoquinone synthesis and its effect cascades to many other key metabolic processes of the algae. Through comparative genomic analysis between the 4-BP-producing bacterium and its algicidally inactive mutant, combined with gene function verification, we identified the gene cluster responsible for 4-BP synthesis, which contains genes encoding chorismate lyase, flavin-dependent halogenase and cytochrome P450. We demonstrated that in near in situ simulated algal blooming seawater, even low concentrations of 4-BP can cause changes in overall phytoplankton community structure with a decline in dinoflagellates and diatoms. Further analyses of the gene sequences from the Tara Oceans expeditions and 2750 whole genome sequences confirmed the ubiquitous presence of 4-BP synthetic genes in diverse bacterial members in the global ocean, suggesting that it is a bacterial tool potentially widely used in global oceans to mediate bacteria-algae antagonistic relationships.
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Affiliation(s)
- Zenghu Zhang
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
- Shandong Energy Institute, Qingdao, 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dehai Li
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, China
| | - Ruize Xie
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Ruoyu Guo
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Shailesh Nair
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Huan Han
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, China
| | - Guojian Zhang
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, China
| | - Qun Zhao
- CAS Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic R. &A. Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Lihua Zhang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic R. &A. Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361101, China
| | - Yongyu Zhang
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
- Shandong Energy Institute, Qingdao, 266101, China.
- Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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4
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Gu X, Li L, Li S, Shi W, Zhong X, Su Y, Wang T. Adaptive evolution and co-evolution of chloroplast genomes in Pteridaceae species occupying different habitats: overlapping residues are always highly mutated. BMC PLANT BIOLOGY 2023; 23:511. [PMID: 37880608 PMCID: PMC10598918 DOI: 10.1186/s12870-023-04523-1] [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: 07/11/2023] [Accepted: 10/13/2023] [Indexed: 10/27/2023]
Abstract
BACKGROUND The evolution of protein residues depends on the mutation rates of their encoding nucleotides, but it may also be affected by co-evolution with other residues. Chloroplasts function as environmental sensors, transforming fluctuating environmental signals into different physiological responses. We reasoned that habitat diversity may affect their rate and mode of evolution, which might be evidenced in the chloroplast genome. The Pteridaceae family of ferns occupy an unusually broad range of ecological niches, which provides an ideal system for analysis. RESULTS We conducted adaptive evolution and intra-molecular co-evolution analyses of Pteridaceae chloroplast DNAs (cpDNAs). The results indicate that the residues undergoing adaptive evolution and co-evolution were mostly independent, with only a few residues being simultaneously involved in both processes, and these overlapping residues tend to exhibit high mutations. Additionally, our data showed that Pteridaceae chloroplast genes are under purifying selection. Regardless of whether we grouped species by lineage (which corresponded with ecological niches), we determined that positively selected residues mainly target photosynthetic genes. CONCLUSIONS Our work provides evidence for the adaptive evolution of Pteridaceae cpDNAs, especially photosynthetic genes, to different habitats and sheds light on the adaptive evolution and co-evolution of proteins.
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Affiliation(s)
- Xiaolin Gu
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Lingling Li
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Sicong Li
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China
| | - Wanxin Shi
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Xiaona Zhong
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Yingjuan Su
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
- Research Institute of Sun Yat-sen University in Shenzhen, Shenzhen, 518057, China.
| | - Ting Wang
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China.
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5
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Tadini L, Jeran N, Domingo G, Zambelli F, Masiero S, Calabritto A, Costantini E, Forlani S, Marsoni M, Briani F, Vannini C, Pesaresi P. Perturbation of protein homeostasis brings plastids at the crossroad between repair and dismantling. PLoS Genet 2023; 19:e1010344. [PMID: 37418499 PMCID: PMC10355426 DOI: 10.1371/journal.pgen.1010344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 05/09/2023] [Indexed: 07/09/2023] Open
Abstract
The chloroplast proteome is a dynamic mosaic of plastid- and nuclear-encoded proteins. Plastid protein homeostasis is maintained through the balance between de novo synthesis and proteolysis. Intracellular communication pathways, including the plastid-to-nucleus signalling and the protein homeostasis machinery, made of stromal chaperones and proteases, shape chloroplast proteome based on developmental and physiological needs. However, the maintenance of fully functional chloroplasts is costly and under specific stress conditions the degradation of damaged chloroplasts is essential to the maintenance of a healthy population of photosynthesising organelles while promoting nutrient redistribution to sink tissues. In this work, we have addressed this complex regulatory chloroplast-quality-control pathway by modulating the expression of two nuclear genes encoding plastid ribosomal proteins PRPS1 and PRPL4. By transcriptomics, proteomics and transmission electron microscopy analyses, we show that the increased expression of PRPS1 gene leads to chloroplast degradation and early flowering, as an escape strategy from stress. On the contrary, the overaccumulation of PRPL4 protein is kept under control by increasing the amount of plastid chaperones and components of the unfolded protein response (cpUPR) regulatory mechanism. This study advances our understanding of molecular mechanisms underlying chloroplast retrograde communication and provides new insight into cellular responses to impaired plastid protein homeostasis.
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Affiliation(s)
- Luca Tadini
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Nicolaj Jeran
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Guido Domingo
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Federico Zambelli
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Simona Masiero
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Anna Calabritto
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Elena Costantini
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Sara Forlani
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Milena Marsoni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Federica Briani
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Candida Vannini
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy
| | - Paolo Pesaresi
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
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6
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Sperdouli I, Ouzounidou G, Moustakas M. Hormesis Responses of Photosystem II in Arabidopsis thaliana under Water Deficit Stress. Int J Mol Sci 2023; 24:ijms24119573. [PMID: 37298524 DOI: 10.3390/ijms24119573] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Since drought stress is one of the key risks for the future of agriculture, exploring the molecular mechanisms of photosynthetic responses to water deficit stress is, therefore, fundamental. By using chlorophyll fluorescence imaging analysis, we evaluated the responses of photosystem II (PSII) photochemistry in young and mature leaves of Arabidopsis thaliana Col-0 (cv Columbia-0) at the onset of water deficit stress (OnWDS) and under mild water deficit stress (MiWDS) and moderate water deficit stress (MoWDS). Moreover, we tried to illuminate the underlying mechanisms in the differential response of PSII in young and mature leaves to water deficit stress in the model plant A. thaliana. Water deficit stress induced a hormetic dose response of PSII function in both leaf types. A U-shaped biphasic response curve of the effective quantum yield of PSII photochemistry (ΦPSII) in A. thaliana young and mature leaves was observed, with an inhibition at MiWDS that was followed by an increase in ΦPSII at MoWDS. Young leaves exhibited lower oxidative stress, evaluated by malondialdehyde (MDA), and higher levels of anthocyanin content compared to mature leaves under both MiWDS (+16%) and MoWDS (+20%). The higher ΦPSII of young leaves resulted in a decreased quantum yield of non-regulated energy loss in PSII (ΦNO), under both MiWDS (-13%) and MoWDS (-19%), compared to mature leaves. Since ΦNO represents singlet-excited oxygen (1O2) generation, this decrease resulted in lower excess excitation energy at PSII, in young leaves under both MiWDS (-10%) and MoWDS (-23%), compared to mature leaves. The hormetic response of PSII function in both young and mature leaves is suggested to be triggered, under MiWDS, by the intensified reactive oxygen species (ROS) generation, which is considered to be beneficial for activating stress defense responses. This stress defense response that was induced at MiWDS triggered an acclimation response in A. thaliana young leaves and provided tolerance to PSII when water deficit stress became more severe (MoWDS). We concluded that the hormesis responses of PSII in A. thaliana under water deficit stress are regulated by the leaf developmental stage that modulates anthocyanin accumulation in a stress-dependent dose.
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Affiliation(s)
- Ilektra Sperdouli
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organization-Dimitra, GR-57001 Thessaloniki, Greece
| | - Georgia Ouzounidou
- Institute of Food Technology, Hellenic Agricultural Organization-Dimitra, GR-14123 Lycovrissi, Greece
| | - Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
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7
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Zhang X, Han Y, Han X, Zhang S, Xiong L, Chen T. Peptide chain release factor DIG8 regulates plant growth by affecting ROS-mediated sugar transportation in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2023; 14:1172275. [PMID: 37063204 PMCID: PMC10102589 DOI: 10.3389/fpls.2023.1172275] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 03/14/2023] [Indexed: 06/19/2023]
Abstract
Chloroplasts have important roles in photosynthesis, stress sensing and retrograde signaling. However, the relationship between chloroplast peptide chain release factor and ROS-mediated plant growth is still unclear. In the present study, we obtained a loss-of-function mutant dig8 by EMS mutation. The dig8 mutant has few lateral roots and a pale green leaf phenotype. By map-based cloning, the DIG8 gene was located on AT3G62910, with a point mutation leading to amino acid substitution in functional release factor domain. Using yeast-two-hybrid and BiFC, we confirmed DIG8 protein was characterized locating in chloroplast by co-localization with plastid marker and interacting with ribosome-related proteins. Through observing by transmission electron microscopy, quantifying ROS content and measuring the transport efficiency of plasmodesmata in dig8 mutant, we found that abnormal thylakoid stack formation and chloroplast dysfunction in the dig8 mutant caused increased ROS activity leading to callose deposition and lower PD permeability. A local sugar supplement partially alleviated the growth retardation phenotype of the mutant. These findings shed light on chloroplast peptide chain release factor-affected plant growth by ROS stress.
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Affiliation(s)
- Xiangxiang Zhang
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Science, Hangzhou Normal University, Hangzhou, China
| | - Yuliang Han
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Science, Hangzhou Normal University, Hangzhou, China
| | - Xiao Han
- College of Life Sciences, Fuzhou University, Fuzhou, China
| | - Siqi Zhang
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Science, Hangzhou Normal University, Hangzhou, China
| | - Liming Xiong
- Department of Biology, Hong Kong Baptist University, Kowloon Tang, Hong Kong, Hong Kong SAR, China
| | - Tao Chen
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Science, Hangzhou Normal University, Hangzhou, China
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8
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Li H, He X, Gao Y, Liu W, Song J, Zhang J. Integrative Analysis of Transcriptome, Proteome, and Phosphoproteome Reveals Potential Roles of Photosynthesis Antenna Proteins in Response to Brassinosteroids Signaling in Maize. PLANTS (BASEL, SWITZERLAND) 2023; 12:1290. [PMID: 36986978 PMCID: PMC10058427 DOI: 10.3390/plants12061290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/09/2023] [Accepted: 03/09/2023] [Indexed: 06/19/2023]
Abstract
Brassinosteroids are a recently discovered group of substances that promote plant growth and productivity. Photosynthesis, which is vital for plant growth and high productivity, is strongly influenced by brassinosteroid signaling. However, the molecular mechanism underlying the photosynthetic response to brassinosteroid signaling in maize remains obscure. Here, we performed integrated transcriptome, proteome, and phosphoproteomic analyses to identify the key photosynthesis pathway that responds to brassinosteroid signaling. Transcriptome analysis suggested that photosynthesis antenna proteins and carotenoid biosynthesis, plant hormone signal transduction, and MAPK signaling in CK VS EBR and CK VS Brz were significantly enriched in the list of differentially expressed genes upon brassinosteroids treatment. Consistently, proteome and phosphoproteomic analyses indicated that photosynthesis antenna and photosynthesis proteins were significantly enriched in the list of differentially expressed proteins. Thus, transcriptome, proteome, and phosphoproteome analyses showed that major genes and proteins related to photosynthesis antenna proteins were upregulated by brassinosteroids treatment in a dose-dependent manner. Meanwhile, 42 and 186 transcription factor (TF) responses to brassinosteroid signals in maize leaves were identified in the CK VS EBR and CK VS Brz groups, respectively. Our study provides valuable information for a better understanding of the molecular mechanism underlying the photosynthetic response to brassinosteroid signaling in maize.
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Affiliation(s)
- Hui Li
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu 611130, China
| | - Xuewu He
- College of Life Science, Sichuan Agricultural University, Ya’an 625014, China
| | - Yuanfen Gao
- College of Life Science, Sichuan Agricultural University, Ya’an 625014, China
| | - Wenjuan Liu
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu 611130, China
| | - Jun Song
- Institute of Quality Standard and Testing Technology Research, Sichuan Academy of Agricultural Sciences, Chengdu 611130, China
| | - Junjie Zhang
- College of Life Science, Sichuan Agricultural University, Ya’an 625014, China
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9
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Research progress on maintaining chloroplast homeostasis under stress conditions: a review. Acta Biochim Biophys Sin (Shanghai) 2023; 55:173-182. [PMID: 36840466 PMCID: PMC10157539 DOI: 10.3724/abbs.2023022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
On a global scale, drought, salinity, extreme temperature, and other abiotic stressors severely limit the quality and yield of crops. Therefore, it is crucial to clarify the adaptation strategies of plants to harsh environments. Chloroplasts are important environmental sensors in plant cells. For plants to thrive in different habitats, chloroplast homeostasis must be strictly regulated, which is necessary to maintain efficient plant photosynthesis and other metabolic reactions under stressful environments. To maintain normal chloroplast physiology, two important biological processes are needed: the import and degradation of chloroplast proteins. The orderly import of chloroplast proteins and the timely degradation of damaged chloroplast components play a key role in adapting plants to their environment. In this review, we briefly described the mechanism of chloroplast TOC-TIC protein transport. The importance and recent progress of chloroplast protein turnover, retrograde signaling, and chloroplast protein degradation under stress are summarized. Furthermore, the potential of targeted regulation of chloroplast homeostasis is emphasized to improve plant adaptation to environmental stresses.
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10
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Wan C, Ling Q. Functions of autophagy in chloroplast protein degradation and homeostasis. FRONTIERS IN PLANT SCIENCE 2022; 13:993215. [PMID: 36247630 PMCID: PMC9557084 DOI: 10.3389/fpls.2022.993215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/05/2022] [Indexed: 06/16/2023]
Abstract
Chloroplasts are defining organelles in plant and algae, which carried out various critical metabolic processes, including photosynthesis. Roles of chloroplast protein homeostasis in plant development and stress adaptation were clearly demonstrated in previous studies, and its maintenance requires internal proteases originated from the prokaryotic ancestor. Recently, increasing evidence revealed that eukaryotic proteolytic pathways, ubiquitin-proteasome system (UPS) and autophagy, are also involved in the turnover of chloroplast proteins, in response to developmental and environmental cues. Notably, chloroplasts can be regulated via the selective degradation of chloroplast materials in a process called chlorophagy. Yet, understandings of the mechanism of chlorophagy are still rudimentary, particularly regarding its initiation and operation. Here we provide an updated overview of autophagy pathways for chloroplast protein degradation and discuss their importance for plant physiology. In addition, recent advance in analogous mitophagy in yeast and mammals will also be discussed, which provides clues for further elucidating the mechanism of chlorophagy.
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Affiliation(s)
- Chen Wan
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qihua Ling
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
- Chinese Academy of Sciences (CAS) and John Innes Centre, Center of Excellence for Plant and Microbial Sciences (CEPAMS), Shanghai, China
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11
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Hand KA, Shabek N. The Role of E3 Ubiquitin Ligases in Chloroplast Function. Int J Mol Sci 2022; 23:9613. [PMID: 36077009 PMCID: PMC9455731 DOI: 10.3390/ijms23179613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 12/14/2022] Open
Abstract
Chloroplasts are ancient organelles responsible for photosynthesis and various biosynthetic functions essential to most life on Earth. Many of these functions require tightly controlled regulatory processes to maintain homeostasis at the protein level. One such regulatory mechanism is the ubiquitin-proteasome system whose fundamental role is increasingly emerging in chloroplasts. In particular, the role of E3 ubiquitin ligases as determinants in the ubiquitination and degradation of specific intra-chloroplast proteins. Here, we highlight recent advances in understanding the roles of plant E3 ubiquitin ligases SP1, COP1, PUB4, CHIP, and TT3.1 as well as the ubiquitin-dependent segregase CDC48 in chloroplast function.
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Affiliation(s)
| | - Nitzan Shabek
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA
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12
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Zhang H, Zhou JF, Kan Y, Shan JX, Ye WW, Dong NQ, Guo T, Xiang YH, Yang YB, Li YC, Zhao HY, Yu HX, Lu ZQ, Guo SQ, Lei JJ, Liao B, Mu XR, Cao YJ, Yu JJ, Lin Y, Lin HX. A genetic module at one locus in rice protects chloroplasts to enhance thermotolerance. Science 2022; 376:1293-1300. [PMID: 35709289 DOI: 10.1126/science.abo5721] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
How the plasma membrane senses external heat-stress signals to communicate with chloroplasts to orchestrate thermotolerance remains elusive. We identified a quantitative trait locus, Thermo-tolerance 3 (TT3), consisting of two genes, TT3.1 and TT3.2, that interact together to enhance rice thermotolerance and reduce grain-yield losses caused by heat stress. Upon heat stress, plasma membrane-localized E3 ligase TT3.1 translocates to the endosomes, on which TT3.1 ubiquitinates chloroplast precursor protein TT3.2 for vacuolar degradation, implying that TT3.1 might serve as a potential thermosensor. Lesser accumulated, mature TT3.2 proteins in chloroplasts are essential for protecting thylakoids from heat stress. Our findings not only reveal a TT3.1-TT3.2 genetic module at one locus that transduces heat signals from plasma membrane to chloroplasts but also provide the strategy for breeding highly thermotolerant crops.
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Affiliation(s)
- Hai Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.,University of the Chinese Academy of Sciences, Beijing 100049, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Ji-Fu Zhou
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yi Kan
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Jun-Xiang Shan
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Wang-Wei Ye
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Nai-Qian Dong
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Tao Guo
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - You-Huang Xiang
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yi-Bing Yang
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Ya-Chao Li
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,University of the Chinese Academy of Sciences, Beijing 100049, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Huai-Yu Zhao
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Hong-Xiao Yu
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zi-Qi Lu
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Shuang-Qin Guo
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Jie-Jie Lei
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Ben Liao
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xiao-Rui Mu
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Ying-Jie Cao
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Jia-Jun Yu
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Youshun Lin
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hong-Xuan Lin
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.,University of the Chinese Academy of Sciences, Beijing 100049, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
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13
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Woodson JD. Control of chloroplast degradation and cell death in response to stress. Trends Biochem Sci 2022; 47:851-864. [DOI: 10.1016/j.tibs.2022.03.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/25/2022] [Accepted: 03/14/2022] [Indexed: 12/16/2022]
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14
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García-Caparrós P, De Filippis L, Gul A, Hasanuzzaman M, Ozturk M, Altay V, Lao MT. Oxidative Stress and Antioxidant Metabolism under Adverse Environmental Conditions: a Review. THE BOTANICAL REVIEW 2021; 87:421-466. [PMID: 0 DOI: 10.1007/s12229-020-09231-1] [Citation(s) in RCA: 123] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/01/2020] [Indexed: 05/25/2023]
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15
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DeTar RA, Barahimipour R, Manavski N, Schwenkert S, Höhner R, Bölter B, Inaba T, Meurer J, Zoschke R, Kunz HH. Loss of inner-envelope K+/H+ exchangers impairs plastid rRNA maturation and gene expression. THE PLANT CELL 2021; 33:2479-2505. [PMID: 34235544 PMCID: PMC8364240 DOI: 10.1093/plcell/koab123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/30/2021] [Indexed: 05/08/2023]
Abstract
The inner-envelope K+ EFFLUX ANTIPORTERS (KEA) 1 and 2 are critical for chloroplast development, ion homeostasis, and photosynthesis. However, the mechanisms by which changes in ion flux across the envelope affect organelle biogenesis remained elusive. Chloroplast development requires intricate coordination between the nuclear genome and the plastome. Many mutants compromised in plastid gene expression (PGE) display a virescent phenotype, that is delayed greening. The phenotypic appearance of Arabidopsis thaliana kea1 kea2 double mutants fulfills this criterion, yet a link to PGE has not been explored. Here, we show that a simultaneous loss of KEA1 and KEA2 results in maturation defects of the plastid ribosomal RNAs. This may be caused by secondary structure changes of rRNA transcripts and concomitant reduced binding of RNA-processing proteins, which we documented in the presence of skewed ion homeostasis in kea1 kea2. Consequently, protein synthesis and steady-state levels of plastome-encoded proteins remain low in mutants. Disturbance in PGE and other signs of plastid malfunction activate GENOMES UNCOUPLED 1-dependent retrograde signaling in kea1 kea2, resulting in a dramatic downregulation of GOLDEN2-LIKE transcription factors to halt expression of photosynthesis-associated nuclear-encoded genes (PhANGs). PhANG suppression delays the development of fully photosynthesizing kea1 kea2 chloroplasts, probably to avoid progressing photo-oxidative damage. Overall, our results reveal that KEA1/KEA2 function impacts plastid development via effects on RNA-metabolism and PGE.
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Affiliation(s)
- Rachael Ann DeTar
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA
| | - Rouhollah Barahimipour
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Nikolay Manavski
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Serena Schwenkert
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Ricarda Höhner
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA
| | - Bettina Bölter
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Takehito Inaba
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Jörg Meurer
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Hans-Henning Kunz
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
- Author for correspondence:
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16
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Alamdari K, Fisher KE, Tano DW, Rai S, Palos K, Nelson ADL, Woodson JD. Chloroplast quality control pathways are dependent on plastid DNA synthesis and nucleotides provided by cytidine triphosphate synthase two. THE NEW PHYTOLOGIST 2021; 231:1431-1448. [PMID: 33993494 DOI: 10.1111/nph.17467] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
Reactive oxygen species (ROS) produced in chloroplasts cause oxidative damage, but also signal to initiate chloroplast quality control pathways, cell death, and gene expression. The Arabidopsis thaliana plastid ferrochelatase two (fc2) mutant produces the ROS singlet oxygen in chloroplasts that activates such signaling pathways, but the mechanisms are largely unknown. Here we characterize one fc2 suppressor mutation and map it to CYTIDINE TRIPHOSPHATE SYNTHASE TWO (CTPS2), which encodes one of five enzymes in Arabidopsis necessary for de novo cytoplasmic CTP (and dCTP) synthesis. The ctps2 mutation reduces chloroplast transcripts and DNA content without similarly affecting mitochondria. Chloroplast nucleic acid content and singlet oxygen signaling are restored by exogenous feeding of the dCTP precursor deoxycytidine, suggesting ctps2 blocks signaling by limiting nucleotides for chloroplast genome maintenance. An investigation of CTPS orthologs in Brassicaceae showed CTPS2 is a member of an ancient lineage distinct from CTPS3. Complementation studies confirmed this analysis; CTPS3 was unable to compensate for CTPS2 function in providing nucleotides for chloroplast DNA and signaling. Our studies link cytoplasmic nucleotide metabolism with chloroplast quality control pathways. Such a connection is achieved by a conserved clade of CTPS enzymes that provide nucleotides for chloroplast function, thereby allowing stress signaling to occur.
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Affiliation(s)
- Kamran Alamdari
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Karen E Fisher
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - David W Tano
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Snigdha Rai
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Kyle Palos
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | | | - Jesse D Woodson
- The School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
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17
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Matilla AJ. Cellular oxidative stress in programmed cell death: focusing on chloroplastic 1O 2 and mitochondrial cytochrome-c release. JOURNAL OF PLANT RESEARCH 2021; 134:179-194. [PMID: 33569718 DOI: 10.1007/s10265-021-01259-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 01/28/2021] [Indexed: 06/12/2023]
Abstract
The programmed cell death (PCD) occurs when the targeted cells have fulfilled their task or under conditions as oxidative stress generated by ROS species. Thus, plants have to deal with the singlet oxygen 1O2 produced in chloroplasts. 1O2 is unlikely to act as a primary retrograde signal owing to its high reactivity and short half-life. In addition to its high toxicity, the 1O2 generated under an excess or low excitation energy might also act as a highly versatile signal triggering chloroplast-to-nucleus retrograde signaling (ChNRS) and nuclear reprogramming or cell death. Molecular and biochemical studies with the flu mutant, which accumulates protochlorophyllide in the dark, demonstrated that chloroplastic 1O2-driven EXECUTER-1 (EX1) and EX2 proteins are involved in the 1O2-dependent response. Both EX1 and EX2 are necessary for full suppression of 1O2-induced gene expression. That is, EXECUTER proteolysis via the ATP-dependent zinc protease (FtsH) is an integral part of 1O2-triggered retrograde signaling. The existence of at least two independent ChNRS involving EX1 and β-cyclocitral, and dihydroactinidiolide and OXI1, respectively, seem clear. Besides, this update also focuses on plant PCD and its relation with mitochondrial cytochrome-c (Cytc) release to cytosol. Changes in the dynamics and morphology of mitochondria were shown during the onset of cell death. The mitochondrial damage and translocation of Cytc may be one of the major causes of PCD triggering. Together, this current overview illustrates the complexity of the cellular response to oxidative stress development. A puzzle with the majority of its pieces still not placed.
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Affiliation(s)
- Angel J Matilla
- Departamento de Biología Funcional, Facultad de Farmacia, Universidad de Santiago de Compostela (USC), Campus Vida, 15782, Santiago de Compostela, A Coruña, Spain.
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18
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Alamdari K, Fisher KE, Sinson AB, Chory J, Woodson JD. Roles for the chloroplast-localized pentatricopeptide repeat protein 30 and the 'mitochondrial' transcription termination factor 9 in chloroplast quality control. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:735-751. [PMID: 32779277 DOI: 10.1111/tpj.14963] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 07/20/2020] [Indexed: 05/11/2023]
Abstract
Chloroplasts constantly experience photo-oxidative stress while performing photosynthesis. This is particularly true under abiotic stresses that lead to the accumulation of reactive oxygen species (ROS) which oxidize DNA, proteins and lipids. Reactive oxygen species can also act as signals to induce acclimation through chloroplast degradation, cell death and nuclear gene expression. To better understand the mechanisms behind ROS signaling from chloroplasts, we have used the Arabidopsis thaliana mutant plastid ferrochelatase two (fc2) that conditionally accumulates the ROS singlet oxygen (1 O2 ) leading to chloroplast degradation and eventually cell death. Here we have mapped mutations that suppress chloroplast degradation in the fc2 mutant and demonstrate that they affect two independent loci (PPR30 and mTERF9) encoding chloroplast proteins predicted to be involved in post-transcriptional gene expression. These mutants exhibited broadly reduced chloroplast gene expression, impaired chloroplast development and reduced chloroplast stress signaling. Levels of 1 O2 , however, could be uncoupled from chloroplast degradation, suggesting that PPR30 and mTERF9 are involved in ROS signaling pathways. In the wild-type background, ppr30 and mTERF9 mutants were also observed to be less susceptible to cell death induced by excess light stress. While broad inhibition of plastid transcription with rifampicin was also able to suppress cell death in fc2 mutants, specific reductions in plastid gene expression using other mutations was not always sufficient. Together these results suggest that plastid gene expression, or the expression of specific plastid genes by PPR30 and mTERF0, is a necessary prerequisite for chloroplasts to activate the 1 O2 signaling pathways to induce chloroplast quality control pathways and/or cell death.
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Affiliation(s)
- Kamran Alamdari
- The School of Plant Sciences, University of Arizona, 1140 E. South Campus Drive, 303 Forbes Building, Tucson, AZ, 85721, USA
| | - Karen E Fisher
- The School of Plant Sciences, University of Arizona, 1140 E. South Campus Drive, 303 Forbes Building, Tucson, AZ, 85721, USA
| | - Andrew B Sinson
- The Division of Biological Sciences, The University of California San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
- Plant Biology Laboratory, The Salk Institute, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Joanne Chory
- Plant Biology Laboratory, The Salk Institute, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
- Howard Hughes Medical Institute, The Salk Institute, 10010 N Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Jesse D Woodson
- The School of Plant Sciences, University of Arizona, 1140 E. South Campus Drive, 303 Forbes Building, Tucson, AZ, 85721, USA
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19
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The Role of Chloroplast Gene Expression in Plant Responses to Environmental Stress. Int J Mol Sci 2020; 21:ijms21176082. [PMID: 32846932 PMCID: PMC7503970 DOI: 10.3390/ijms21176082] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 12/16/2022] Open
Abstract
Chloroplasts are plant organelles that carry out photosynthesis, produce various metabolites, and sense changes in the external environment. Given their endosymbiotic origin, chloroplasts have retained independent genomes and gene-expression machinery. Most genes from the prokaryotic ancestors of chloroplasts were transferred into the nucleus over the course of evolution. However, the importance of chloroplast gene expression in environmental stress responses have recently become more apparent. Here, we discuss the emerging roles of the distinct chloroplast gene expression processes in plant responses to environmental stresses. For example, the transcription and translation of psbA play an important role in high-light stress responses. A better understanding of the connection between chloroplast gene expression and environmental stress responses is crucial for breeding stress-tolerant crops better able to cope with the rapidly changing environment.
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20
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Dmitrieva VA, Tyutereva EV, Voitsekhovskaja OV. Singlet Oxygen in Plants: Generation, Detection, and Signaling Roles. Int J Mol Sci 2020; 21:E3237. [PMID: 32375245 PMCID: PMC7247340 DOI: 10.3390/ijms21093237] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/27/2020] [Accepted: 04/29/2020] [Indexed: 01/17/2023] Open
Abstract
Singlet oxygen (1O2) refers to the lowest excited electronic state of molecular oxygen. It easily oxidizes biological molecules and, therefore, is cytotoxic. In plant cells, 1O2 is formed mostly in the light in thylakoid membranes by reaction centers of photosystem II. In high concentrations, 1O2 destroys membranes, proteins and DNA, inhibits protein synthesis in chloroplasts leading to photoinhibition of photosynthesis, and can result in cell death. However, 1O2 also acts as a signal relaying information from chloroplasts to the nucleus, regulating expression of nuclear genes. In spite of its extremely short lifetime, 1O2 can diffuse from the chloroplasts into the cytoplasm and the apoplast. As shown by recent studies, 1O2-activated signaling pathways depend not only on the levels but also on the sites of 1O2 production in chloroplasts, and can activate two types of responses, either acclimation to high light or programmed cell death. 1O2 can be produced in high amounts also in root cells during drought stress. This review summarizes recent advances in research on mechanisms and sites of 1O2 generation in plants, on 1O2-activated pathways of retrograde- and cellular signaling, and on the methods to study 1O2 production in plants.
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Affiliation(s)
| | | | - Olga V. Voitsekhovskaja
- Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, Saint Petersburg 197376, Russia; (V.A.D.); (E.V.T.)
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21
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Tadini L, Peracchio C, Trotta A, Colombo M, Mancini I, Jeran N, Costa A, Faoro F, Marsoni M, Vannini C, Aro EM, Pesaresi P. GUN1 influences the accumulation of NEP-dependent transcripts and chloroplast protein import in Arabidopsis cotyledons upon perturbation of chloroplast protein homeostasis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:1198-1220. [PMID: 31648387 DOI: 10.1111/tpj.14585] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 10/09/2019] [Accepted: 10/21/2019] [Indexed: 05/21/2023]
Abstract
Correct chloroplast development and function require co-ordinated expression of chloroplast and nuclear genes. This is achieved through chloroplast signals that modulate nuclear gene expression in accordance with the chloroplast's needs. Genetic evidence indicates that GUN1, a chloroplast-localized pentatricopeptide repeat (PPR) protein with a C-terminal Small MutS-Related (SMR) domain, is involved in integrating multiple developmental and stress-related signals in both young seedlings and adult leaves. Recently, GUN1 was found to interact physically with factors involved in chloroplast protein homeostasis, and with enzymes of tetrapyrrole biosynthesis in adult leaves that function in various retrograde signalling pathways. Here we show that following perturbation of chloroplast protein homeostasis: (i) by growth in lincomycin-containing medium; or (ii) in mutants defective in either the FtsH protease complex (ftsh), plastid ribosome activity (prps21-1 and prpl11-1) or plastid protein import and folding (cphsc70-1), GUN1 influences NEP-dependent transcript accumulation during cotyledon greening and also intervenes in chloroplast protein import.
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Affiliation(s)
- Luca Tadini
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milano, Italy
| | - Carlotta Peracchio
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milano, Italy
| | - Andrea Trotta
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turku, Finland
| | - Monica Colombo
- Centro Ricerca e Innovazione, Fondazione Edmund Mach, 38010, San Michele all'Adige, Italy
| | - Ilaria Mancini
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turku, Finland
| | - Nicolaj Jeran
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milano, Italy
| | - Alex Costa
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milano, Italy
| | - Franco Faoro
- Dipartimento di Scienze Agrarie e Ambientali - Produzione, Territorio, Agroenergia, Università degli Studi di Milano, 20133, Milano, Italy
| | - Milena Marsoni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J.H. Dunant 3, 21100, Varese, Italy
| | - Candida Vannini
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J.H. Dunant 3, 21100, Varese, Italy
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turku, Finland
| | - Paolo Pesaresi
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milano, Italy
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22
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Richardson LGL, Schnell DJ. Origins, function, and regulation of the TOC-TIC general protein import machinery of plastids. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:1226-1238. [PMID: 31730153 PMCID: PMC7031061 DOI: 10.1093/jxb/erz517] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 11/14/2019] [Indexed: 05/11/2023]
Abstract
The evolution of chloroplasts from the original endosymbiont involved the transfer of thousands of genes from the ancestral bacterial genome to the host nucleus, thereby combining the two genetic systems to facilitate coordination of gene expression and achieve integration of host and organelle functions. A key element of successful endosymbiosis was the evolution of a unique protein import system to selectively and efficiently target nuclear-encoded proteins to their site of function within the chloroplast after synthesis in the cytoplasm. The chloroplast TOC-TIC (translocon at the outer chloroplast envelope-translocon at the inner chloroplast envelope) general protein import system is conserved across the plant kingdom, and is a system of hybrid origin, with core membrane transport components adapted from bacterial protein targeting systems, and additional components adapted from host genes to confer the specificity and directionality of import. In vascular plants, the TOC-TIC system has diversified to mediate the import of specific, functionally related classes of plastid proteins. This functional diversification occurred as the plastid family expanded to fulfill cell- and tissue-specific functions in terrestrial plants. In addition, there is growing evidence that direct regulation of TOC-TIC activities plays an essential role in the dynamic remodeling of the organelle proteome that is required to coordinate plastid biogenesis with developmental and physiological events.
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Affiliation(s)
- Lynn G L Richardson
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
| | - Danny J Schnell
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
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23
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Zhao X, Huang J, Chory J. Unraveling the Linkage between Retrograde Signaling and RNA Metabolism in Plants. TRENDS IN PLANT SCIENCE 2020; 25:141-147. [PMID: 31791654 DOI: 10.1016/j.tplants.2019.10.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/09/2019] [Accepted: 10/23/2019] [Indexed: 05/25/2023]
Abstract
Retrograde signals are signals that originate in organelles to regulate nuclear gene expression. In plant cells, retrograde signaling from both chloroplasts and mitochondria is essential for plant development and growth. Over the past few years, substantial progress has been made in unraveling the linkages between chloroplast retrograde signaling and nuclear RNA metabolism processes or plastidial RNA editing. These findings add to the complexity of the regulation of organelle-to-nucleus communication. Chloroplast development and function rely on the coordinated regulation of chloroplast and nuclear gene expression, especially under stress conditions. A better understanding of retrograde signaling and RNA metabolism, as well as their connection, is essential for breeding stress-tolerant plants to cope with the dynamic and rapidly changing environment.
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Affiliation(s)
- Xiaobo Zhao
- Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Plant Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
| | - Jianyan Huang
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Plant Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Joanne Chory
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Plant Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
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24
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Woodson JD. Chloroplast stress signals: regulation of cellular degradation and chloroplast turnover. CURRENT OPINION IN PLANT BIOLOGY 2019; 52:30-37. [PMID: 31442733 DOI: 10.1016/j.pbi.2019.06.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 06/02/2019] [Accepted: 06/05/2019] [Indexed: 05/11/2023]
Abstract
For 40 years, it has been known that chloroplasts signal to the nucleus and the cell to coordinate gene expression, maximize photosynthesis, and avoid stress. However, the signaling mechanisms have been challenging to uncover due to the complexity of these signals and the stresses that induce them. New research has shown that many signals are induced by singlet oxygen, a natural by-product of inefficient photosynthesis. Chloroplast singlet oxygen not only regulates nuclear gene expression, but also cellular degradation and cell death. Stressed chloroplasts also induce post-translational mechanisms, including autophagy, that allows individual chloroplasts to regulate their own degradation and turnover. Such chloroplast quality control pathways may allow cells to maintain healthy populations of chloroplasts and to avoid cumulative photo-oxidative stress in stressful environments.
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Affiliation(s)
- Jesse D Woodson
- University of Arizona, School of Plant Sciences, 303 Forbes Hall, 1140 E. South Campus Drive, Tucson, AZ 85721-0036, United States.
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25
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Cha JY, Lee DY, Ali I, Jeong SY, Shin B, Ji H, Kim JS, Kim MG, Kim WY. Arabidopsis GIGANTEA negatively regulates chloroplast biogenesis and resistance to herbicide butafenacil. PLANT CELL REPORTS 2019; 38:793-801. [PMID: 30968200 DOI: 10.1007/s00299-019-02409-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/28/2019] [Indexed: 06/09/2023]
Abstract
Arabidopsis GI negatively regulates chloroplast biogenesis and resistance to the herbicide butafenacil by enhanced activity and transcriptional levels of antioxidant enzymes Chloroplast biogenesis is blocked by retrograde signaling triggered by diverse internal and external cues, including sugar, reactive oxygen species (ROS), phytohormones, and abiotic stress. Efficient chloroplast biogenesis is essential for crop productivity due to its effect on photosynthetic efficiency, and is associated with agronomic traits such as insect/disease resistance, herbicide resistance, and abiotic stress tolerance. Here, we show that the circadian clock-controlled gene GIGANTEA (GI) regulates chloroplast biogenesis in Arabidopsis thaliana. The gi-2 mutant showed reduced sensitivity to the chloroplast biogenesis inhibitor lincomycin, maintaining high levels of photosynthetic proteins. By contrast, wild-type and GI-overexpressing plants were sensitive to lincomycin, with variegated leaves and reduced photosynthetic protein levels. GI is degraded by lincomycin, suggesting that GI is genetically linked to chloroplast biogenesis. The GI mutant alleles gi-1 and gi-2 were resistant to the herbicide butafenacil, which inhibits protoporphyrinogen IX oxidase activity and triggers ROS-mediated cell death via the accumulation of chlorophyll precursors. Butafenacil-mediated accumulation of superoxide anions and H2O2 was not detected in gi-1 or gi-2, as revealed by histochemical staining. The activities of the antioxidant enzymes superoxide dismutase, peroxidase, and catalase were 1.2-1.4-fold higher in both gi mutants compared to the wild type. Finally, the expression levels of antioxidant enzyme genes were 1.5-2-fold higher in the mutants than in the wild type. These results suggest that GI negatively regulates chloroplast biogenesis and resistance to the herbicide butafenacil, providing evidence for a genetic link between GI and chloroplast biogenesis, which could facilitate the development of herbicide-resistant crops.
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Affiliation(s)
- Joon-Yung Cha
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Institute of Agricultural and Life Science (IALS), Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Da-Yeon Lee
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Institute of Agricultural and Life Science (IALS), Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Imdad Ali
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Institute of Agricultural and Life Science (IALS), Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Song Yi Jeong
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Institute of Agricultural and Life Science (IALS), Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Bobae Shin
- Department of Agricultural Chemistry and Food Science and Technology, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Hyunjung Ji
- Department of Agricultural Chemistry and Food Science and Technology, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Jung Sun Kim
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, 54874, Republic of Korea
| | - Min-Gab Kim
- College of Pharmacy and Research Institute of Pharmaceutical Science, PMBBRC, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Woe-Yeon Kim
- Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Institute of Agricultural and Life Science (IALS), Gyeongsang National University, Jinju, 52828, Republic of Korea.
- Department of Agricultural Chemistry and Food Science and Technology, Gyeongsang National University, Jinju, 52828, Republic of Korea.
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26
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Krieger-Liszkay A, Krupinska K, Shimakawa G. The impact of photosynthesis on initiation of leaf senescence. PHYSIOLOGIA PLANTARUM 2019; 166:148-164. [PMID: 30629302 DOI: 10.1111/ppl.12921] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/21/2018] [Accepted: 01/07/2019] [Indexed: 05/20/2023]
Abstract
Senescence is the last stage of leaf development preceding the death of the organ, and it is important for nutrient remobilization and for feeding sink tissues. There are many reports on leaf senescence, but the mechanisms initiating leaf senescence are still poorly understood. Leaf senescence is affected by many environmental factors and seems to vary in different species and even varieties of plants, which makes it difficult to generalize the mechanism. Here, we give an overview on studies reporting about alterations in the composition of the photosynthetic electron transport chain in chloroplasts during senescence. We hypothesize that alternative electron flow and related generation of the proton motive force required for ATP synthesis become increasingly important during progression of senescence. We address the generation of reactive oxygen species (ROS) in chloroplasts in the initiation of senescence, retrograde signaling from the chloroplast to the nucleus and ROS-dependent signaling associated with leaf senescence. Finally, a few ideas for increasing crop yields by increasing the chloroplast lifespan are presented.
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Affiliation(s)
- Anja Krieger-Liszkay
- Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA) Saclay, Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, F-91198, Gif-sur-Yvette, France
| | - Karin Krupinska
- Institute of Botany, University of Kiel, D-24098, Kiel, Germany
| | - Ginga Shimakawa
- Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA) Saclay, Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, F-91198, Gif-sur-Yvette, France
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27
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Yang X, Li Y, Qi M, Liu Y, Li T. Targeted Control of Chloroplast Quality to Improve Plant Acclimation: From Protein Import to Degradation. FRONTIERS IN PLANT SCIENCE 2019; 10:958. [PMID: 31402924 PMCID: PMC6670758 DOI: 10.3389/fpls.2019.00958] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 07/09/2019] [Indexed: 05/07/2023]
Abstract
The chloroplast is an important energy-producing organelle acting as an environmental sensor for the plant cell. The normal turnover of the entire damaged chloroplast and its specific components is required for efficient photosynthesis and other metabolic reactions under stress conditions. Nuclear-encoded proteins must be imported into the chloroplast through different membrane transport complexes, and the orderly protein import plays an important role in plant adaptive regulation. Under adverse environmental conditions, the damaged chloroplast or its specific components need to be degraded efficiently to ensure normal cell function. In this review, we discuss the molecular mechanism of protein import and degradation in the chloroplast. Specifically, quality control of chloroplast from protein import to degradation and associated regulatory pathways are discussed to better understand how plants adapt to environmental stress by fine-tuning chloroplast homeostasis, which will benefit breeding approaches to improve crop yield.
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28
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Reagan BC, Ganusova EE, Fernandez JC, McCray TN, Burch-Smith TM. RNA on the move: The plasmodesmata perspective. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 275:1-10. [PMID: 30107876 DOI: 10.1016/j.plantsci.2018.07.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/25/2018] [Accepted: 07/04/2018] [Indexed: 05/11/2023]
Abstract
It is now widely accepted that plant RNAs can have effects at sites far away from their sites of synthesis. Cellular mRNA transcripts, endogenous small RNAs and defense-related small RNAs all move from cell to cell via plasmodesmata (PD), and may even move long distances in the phloem. Despite their small size, PD have complicated substructures, and the area of the pore available for RNA trafficking can be remarkably small. The intent of this review is to bring into focus the role of PD in cell-to-cell and long distance communication in plants. We consider how cellular RNAs could move through the cell to the PD and thence through PD. The protein composition of PD and the possible roles of PD proteins in RNA trafficking are also discussed. Recent evidence for RNA metabolism in organelles acting as a factor in controlling PD flux is also presented, highlighting new aspects of plant intra- and intercellular communication. It is clear that while the phenomenon of RNA mobility is common and essential, many questions remain, and these have been highlighted throughout this review.
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Affiliation(s)
- Brandon C Reagan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States
| | - Elena E Ganusova
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States
| | - Jessica C Fernandez
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States
| | - Tyra N McCray
- School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, United States
| | - Tessa M Burch-Smith
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States; School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996, United States.
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29
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Guadagno CR, Ewers BE, Weinig C. Circadian Rhythms and Redox State in Plants: Till Stress Do Us Part. FRONTIERS IN PLANT SCIENCE 2018; 9:247. [PMID: 29556244 PMCID: PMC5844964 DOI: 10.3389/fpls.2018.00247] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 02/12/2018] [Indexed: 05/22/2023]
Abstract
A growing body of evidence demonstrates a significant relationship between cellular redox state and circadian rhythms. Each day these two vital components of plant biology influence one another, dictating the pace for metabolism and physiology. Diverse environmental stressors can disrupt this condition and, although plant scientists have made significant progress in re-constructing functional networks of plant stress responses, stress impacts on the clock-redox crosstalk is poorly understood. Inter-connected phenomena such as redox state and metabolism, internal and external environments, cellular homeostasis and rhythms can impede predictive understanding of coordinated regulation of plant stress response. The integration of circadian clock effects into predictive network models is likely to increase final yield and better predict plant responses to stress. To achieve such integrated understanding, it is necessary to consider the internal clock not only as a gatekeeper of environmental responses but also as a target of stress syndromes. Using chlorophyll fluorescence as a reliable and high-throughput probe of stress coupled to functional genomics and metabolomics will provide insights on the crosstalk across a wide range of stress severity and duration, including potential insights into oxidative stress response and signaling. We suggest the efficiency of photosystem II in light conditions (Fv'/Fm') to be the most dynamic of the fluorescence variables and therefore the most reliable parameter to follow the stress response from early sensing to mortality.
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Affiliation(s)
| | - Brent E. Ewers
- Department of Botany, University of Wyoming, Laramie, WY, United States
- Program in Ecology, University of Wyoming, Laramie, WY, United States
| | - Cynthia Weinig
- Department of Botany, University of Wyoming, Laramie, WY, United States
- Program in Ecology, University of Wyoming, Laramie, WY, United States
- Department of Molecular and Cellular Life Sciences, University of Wyoming, Laramie, WY, United States
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30
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Otegui MS. Vacuolar degradation of chloroplast components: autophagy and beyond. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:741-750. [PMID: 28992297 DOI: 10.1093/jxb/erx234] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/10/2017] [Indexed: 05/21/2023]
Abstract
Chloroplast degradation during natural or stress-induced senescence requires the participation of both plastidic and extraplastidic degradative pathways. As part of the extraplastidic pathways, chloroplasts export stroma, envelope, and thylakoid proteins in membrane-bound organelles that are ultimately degraded in vacuoles. Some of these pathways, such as the formation of senescence-associated vacuoles (SAVs) and CV-containing vesicles (CCVs), do not depend on autophagy, whereas delivery of Rubisco-containing bodies (RCBs), ATI1-PS (ATG8-interacting Protein 1) bodies, and small starch-like granule (SSLG) bodies is autophagy dependent. In addition, autophagy of entire chloroplasts delivers damaged chloroplasts into the vacuolar lumen for degradation. This review summarizes the autophagy-dependent and independent trafficking mechanisms by which plant cells degrade chloroplast components in vacuoles.
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Affiliation(s)
- Marisa S Otegui
- Laboratory of Cell and Molecular Biology and Departments of Botany and Genetics, University of Wisconsin-Madison, WI, USA
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31
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Gao J, Wang H, Yuan Q, Feng Y. Structure and Function of the Photosystem Supercomplexes. FRONTIERS IN PLANT SCIENCE 2018; 9:357. [PMID: 29616068 PMCID: PMC5869908 DOI: 10.3389/fpls.2018.00357] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 03/02/2018] [Indexed: 05/21/2023]
Abstract
Photosynthesis converts solar energy into chemical energy to sustain all life on earth by providing oxygen and food, and controlling the atmospheric carbon dioxide. During this process, the water-splitting and oxygen-evolving reaction is catalyzed by photosystem II (PSII), while photosystem I (PSI) generates the reducing power for the reduction of NADP+ to NADPH. Together with their peripheral light-harvesting complexes (LHCs), photosystems function as multisubunit supercomplexes located in the thylakoid membranes of cyanobacteria, algae, and plants. Recent advances in single-particle cryo-electron microscopy (cryoEM), X-ray free electron laser (XFEL) and other techniques have revealed unprecedented structural and catalytic details concerning the two supercomplexes. Several high-resolution structures of the complexes from plants were solved, and serial time-resolved crystallography and "radiation-damage-free" femtosecond XFEL also provided important insights into the mechanism of water oxidation. Here, we review these exciting advances in the studies of the photosystem supercomplexes with an emphasis on PSII-LHCII, propose presently unresolved problems in this field, and suggest potential tendencies for future studies.
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Affiliation(s)
- Jinlan Gao
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hao Wang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Qipeng Yuan
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Yue Feng
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
- *Correspondence: Yue Feng, ;
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32
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Chloroplast signaling and quality control. Essays Biochem 2017; 62:13-20. [DOI: 10.1042/ebc20170048] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/06/2017] [Accepted: 10/13/2017] [Indexed: 11/17/2022]
Abstract
Although chloroplasts contain their own genetic system and are semi-autonomous cell organelles, plastid biogenesis and homeostasis are heavily dependent on the nucleo-cytosolic compartment. These two cellular compartments are closely co-ordinated through a complex signaling network comprising both anterograde and retrograde signaling chains. Developmental changes or any perturbation in the chloroplast system induced by a particular stress resulting from changes in environmental conditions such as excess light, elevated temperature, nutrient limitation, pathogen infection, give rise to specific signals. They migrate out of the chloroplast and are perceived by the nucleus where they elicit changes in expression of particular genes that allow for the maintenance of plastid homeostasis toward environmental cues. These genes mainly include those of photosynthesis-associated proteins, chaperones, proteases, nucleases and immune/defense proteins. Besides this transcriptional response, a chloroplast quality control system exists that is involved in the repair and turnover of damaged plastid proteins. This system degrades aggregated or damaged proteins and it can even remove entire chloroplasts when they have suffered heavy damage. This response comprises several processes such as plastid autophagy and ubiquitin–proteasome mediated proteolysis that occurs on the plastid envelope through the action of the ubiquitin–proteasome system.
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33
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Nielson JR, Fredrickson EK, Waller TC, Rendón OZ, Schubert HL, Lin Z, Hill CP, Rutter J. Sterol Oxidation Mediates Stress-Responsive Vms1 Translocation to Mitochondria. Mol Cell 2017; 68:673-685.e6. [PMID: 29149595 PMCID: PMC5837041 DOI: 10.1016/j.molcel.2017.10.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/03/2017] [Accepted: 10/17/2017] [Indexed: 12/25/2022]
Abstract
Vms1 translocates to damaged mitochondria in response to stress, whereupon its binding partner, Cdc48, contributes to mitochondrial protein homeostasis. Mitochondrial targeting of Vms1 is mediated by its conserved mitochondrial targeting domain (MTD), which, in unstressed conditions, is inhibited by intramolecular binding to the Vms1 leucine-rich sequence (LRS). Here, we report a 2.7 Å crystal structure of Vms1 that reveals that the LRS lies in a hydrophobic groove in the autoinhibited MTD. We also demonstrate that the oxidized sterol, ergosterol peroxide, is necessary and sufficient for Vms1 localization to mitochondria, through binding the MTD in an interaction that is competitive with binding to the LRS. These data support a model in which stressed mitochondria generate an oxidized sterol receptor that recruits Vms1 to support mitochondrial protein homeostasis.
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Affiliation(s)
- Jason R Nielson
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Eric K Fredrickson
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - T Cameron Waller
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Olga Zurita Rendón
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Heidi L Schubert
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Zhenjian Lin
- Department of Medicinal Chemistry, University of Utah College of Pharmacy, Salt Lake City, UT 84112, USA
| | - Christopher P Hill
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
| | - Jared Rutter
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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34
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Börner T. The discovery of plastid-to-nucleus retrograde signaling-a personal perspective. PROTOPLASMA 2017; 254:1845-1855. [PMID: 28337540 PMCID: PMC5610210 DOI: 10.1007/s00709-017-1104-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/10/2017] [Indexed: 05/21/2023]
Abstract
DNA and machinery for gene expression have been discovered in chloroplasts during the 1960s. It was soon evident that the chloroplast genome is relatively small, that most genes for chloroplast-localized proteins reside in the nucleus and that chloroplast membranes, ribosomes, and protein complexes are composed of proteins encoded in both the chloroplast and the nuclear genome. This situation has made the existence of mechanisms highly probable that coordinate the gene expression in plastids and nucleus. In the 1970s, the first evidence for plastid signals controlling nuclear gene expression was provided by studies on plastid ribosome deficient mutants with reduced amounts and/or activities of nuclear-encoded chloroplast proteins including the small subunit of Rubisco, ferredoxin NADP+ reductase, and enzymes of the Calvin cycle. This review describes first models of plastid-to-nucleus signaling and their discovery. Today, many plastid signals are known. They do not only balance gene expression in chloroplasts and nucleus during developmental processes but are also generated in response to environmental changes sensed by the organelles.
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Affiliation(s)
- Thomas Börner
- Institute of Biology, Molecular Genetics, Humboldt University Berlin, Rhoda Erdmann Haus, Philippstr 13, 10115, Berlin, Germany.
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35
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Yang M, Jiang JP, Xie X, Chu YD, Fan Y, Cao XP, Xue S, Chi ZY. Chloroplasts Isolation from Chlamydomonas reinhardtii under Nitrogen Stress. FRONTIERS IN PLANT SCIENCE 2017; 8:1503. [PMID: 28900438 PMCID: PMC5581827 DOI: 10.3389/fpls.2017.01503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 08/14/2017] [Indexed: 06/07/2023]
Abstract
Triacylglycerols are produced in abundance through chloroplast and endoplasmic reticulum pathways in some microalgae exposed to stress, though the relative contribution of either pathway remains elusive. Characterization of these pathways requires isolation of the organelles. In this study, an efficient and reproducible approach, including homogenous batch cultures of nitrogen-deprived algal cells in photobioreactors, gentle cell disruption using a simple custom-made disruptor with mechanical shear force, optimized differential centrifugation and Percoll density gradient centrifugation, was developed to isolate chloroplasts from Chlamydomonas reinhardtii subjected to nitrogen stress. Using this approach, the maximum limited stress duration was 4 h and the stressed cells exhibited 19 and 32% decreases in intracellular chlorophyll and nitrogen content, respectively. Chloroplasts with 48 - 300 μg chlorophyll were successfully isolated from stressed cells containing 10 mg chlorophyll. These stressed chloroplasts appeared intact, as monitored by ultrastructure observation and a novel quality control method involving the fatty acid biomarkers. This approach can provide sufficient quantities of intact stressed chloroplasts for subcellular biochemical studies in microalgae.
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Affiliation(s)
- Miao Yang
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of SciencesDalian, China
- University of Chinese Academy of SciencesBeijing, China
- School of Life Sciences and Biotechnology, Dalian University of TechnologyDalian, China
| | - Jun-Peng Jiang
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of SciencesDalian, China
- University of Chinese Academy of SciencesBeijing, China
| | - Xi Xie
- Liaoning Ocean and Fisheries Science Research InstituteDalian, China
| | - Ya-Dong Chu
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of SciencesDalian, China
| | - Yan Fan
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of SciencesDalian, China
- University of Chinese Academy of SciencesBeijing, China
| | - Xu-Peng Cao
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of SciencesDalian, China
| | - Song Xue
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of SciencesDalian, China
| | - Zhan-You Chi
- School of Life Sciences and Biotechnology, Dalian University of TechnologyDalian, China
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36
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Leister D, Wang L, Kleine T. Organellar Gene Expression and Acclimation of Plants to Environmental Stress. FRONTIERS IN PLANT SCIENCE 2017; 8:387. [PMID: 28377785 PMCID: PMC5359298 DOI: 10.3389/fpls.2017.00387] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/07/2017] [Indexed: 05/03/2023]
Abstract
Organelles produce ATP and a variety of vital metabolites, and are indispensable for plant development. While most of their original gene complements have been transferred to the nucleus in the course of evolution, they retain their own genomes and gene-expression machineries. Hence, organellar function requires tight coordination between organellar gene expression (OGE) and nuclear gene expression (NGE). OGE requires various nucleus-encoded proteins that regulate transcription, splicing, trimming, editing, and translation of organellar RNAs, which necessitates nucleus-to-organelle (anterograde) communication. Conversely, changes in OGE trigger retrograde signaling that modulates NGE in accordance with the current status of the organelle. Changes in OGE occur naturally in response to developmental and environmental changes, and can be artificially induced by inhibitors such as lincomycin or mutations that perturb OGE. Focusing on the model plant Arabidopsis thaliana and its plastids, we review here recent findings which suggest that perturbations of OGE homeostasis regularly result in the activation of acclimation and tolerance responses, presumably via retrograde signaling.
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