101
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Paulsen C, Carroll KS. Cysteine-mediated redox signaling: chemistry, biology, and tools for discovery. Chem Rev 2013; 113:4633-79. [PMID: 23514336 PMCID: PMC4303468 DOI: 10.1021/cr300163e] [Citation(s) in RCA: 815] [Impact Index Per Article: 74.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Indexed: 02/06/2023]
Affiliation(s)
- Candice
E. Paulsen
- Department of Chemistry, The Scripps Research
Institute, Jupiter, Florida, 33458, United States
| | - Kate S. Carroll
- Department of Chemistry, The Scripps Research
Institute, Jupiter, Florida, 33458, United States
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102
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Yu QB, Lu Y, Ma Q, Zhao TT, Huang C, Zhao HF, Zhang XL, Lv RH, Yang ZN. TAC7, an essential component of the plastid transcriptionally active chromosome complex, interacts with FLN1, TAC10, TAC12 and TAC14 to regulate chloroplast gene expression in Arabidopsis thaliana. PHYSIOLOGIA PLANTARUM 2013; 148:408-21. [PMID: 23082802 DOI: 10.1111/j.1399-3054.2012.01718.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 10/05/2012] [Accepted: 10/09/2012] [Indexed: 05/03/2023]
Abstract
Transcriptionally active chromosome (TAC) is a fraction of protein/DNA complexes with RNA polymerase activity in the plastid. However, the function of most TAC proteins remains unknown. Here, we isolated two allelic mutants of the gene for a TAC component, TAC7, and performed functional analysis in plastid gene expression and chloroplast development in Arabidopsis. tac7-1 is a mutant with a premature translation termination isolated from a population treated with ethyl methane sulfonate, and tac7-2 is a transfer-DNA tagging mutant. Both of them showed an albino phenotype when grown under normal light conditions, and a few appressed membranes were observed inside the defective chloroplasts. These data indicate that TAC7 is important for thylakoid biogenesis. The TAC7 gene encodes an uncharacterized 161 amino acids polypeptide localized in chloroplast. The transcriptional levels of plastid-encoded polymerase (PEP)-dependent genes were downregulated in tac7-2, suggesting that PEP activity was decreased in the mutant. Yeast two-hybrid assay shows that TAC7 can interact with the four TAC components including FLN1, TAC10, TAC12 and TAC14 which are involved in redox state changes, phosphorylation processes and phytochrome-dependent light signaling, respectively, These data indicate that TAC7 plays an important role for TAC to regulate PEP-dependent chloroplast gene expression and chloroplast development.
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Affiliation(s)
- Qing-Bo Yu
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China
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103
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Kurepin LV, Dahal KP, Savitch LV, Singh J, Bode R, Ivanov AG, Hurry V, Hüner NPA. Role of CBFs as integrators of chloroplast redox, phytochrome and plant hormone signaling during cold acclimation. Int J Mol Sci 2013; 14:12729-63. [PMID: 23778089 PMCID: PMC3709810 DOI: 10.3390/ijms140612729] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 05/24/2013] [Accepted: 06/06/2013] [Indexed: 11/16/2022] Open
Abstract
Cold acclimation of winter cereals and other winter hardy species is a prerequisite to increase subsequent freezing tolerance. Low temperatures upregulate the expression of C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB1) which in turn induce the expression of COLD-REGULATED (COR) genes. We summarize evidence which indicates that the integration of these interactions is responsible for the dwarf phenotype and enhanced photosynthetic performance associated with cold-acclimated and CBF-overexpressing plants. Plants overexpressing CBFs but grown at warm temperatures mimic the cold-tolerant, dwarf, compact phenotype; increased photosynthetic performance; and biomass accumulation typically associated with cold-acclimated plants. In this review, we propose a model whereby the cold acclimation signal is perceived by plants through an integration of low temperature and changes in light intensity, as well as changes in light quality. Such integration leads to the activation of the CBF-regulon and subsequent upregulation of COR gene and GA 2-oxidase (GA2ox) expression which results in a dwarf phenotype coupled with increased freezing tolerance and enhanced photosynthetic performance. We conclude that, due to their photoautotrophic nature, plants do not rely on a single low temperature sensor, but integrate changes in light intensity, light quality, and membrane viscosity in order to establish the cold-acclimated state. CBFs appear to act as master regulators of these interconnecting sensing/signaling pathways.
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Affiliation(s)
- Leonid V. Kurepin
- Department of Biology and the Biotron Center for Experimental Climate Change Research, Western University, London, ON N6A 5B7, Canada; E-Mails: (R.B.); (A.G.I.)
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Umeå 901 87, Sweden; E-Mail:
- Authors to whom correspondence should be addressed; E-Mails: (L.V.K.); (N.P.A.H.); Tel.: +1-519-661-2111 (ext. 86638) (L.V.K.); +1-519-661-2111 (ext. 86488) (N.P.A.H.); Fax: +1-519-850-2343(L.V.K. & N.P.A.H.)
| | - Keshav P. Dahal
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada; E-Mail:
| | - Leonid V. Savitch
- Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada; E-Mails: (L.V.S.); (J.S.)
| | - Jas Singh
- Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada; E-Mails: (L.V.S.); (J.S.)
| | - Rainer Bode
- Department of Biology and the Biotron Center for Experimental Climate Change Research, Western University, London, ON N6A 5B7, Canada; E-Mails: (R.B.); (A.G.I.)
| | - Alexander G. Ivanov
- Department of Biology and the Biotron Center for Experimental Climate Change Research, Western University, London, ON N6A 5B7, Canada; E-Mails: (R.B.); (A.G.I.)
| | - Vaughan Hurry
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Umeå 901 87, Sweden; E-Mail:
| | - Norman P. A. Hüner
- Department of Biology and the Biotron Center for Experimental Climate Change Research, Western University, London, ON N6A 5B7, Canada; E-Mails: (R.B.); (A.G.I.)
- Authors to whom correspondence should be addressed; E-Mails: (L.V.K.); (N.P.A.H.); Tel.: +1-519-661-2111 (ext. 86638) (L.V.K.); +1-519-661-2111 (ext. 86488) (N.P.A.H.); Fax: +1-519-850-2343(L.V.K. & N.P.A.H.)
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104
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Rochaix JD. Redox regulation of thylakoid protein kinases and photosynthetic gene expression. Antioxid Redox Signal 2013; 18:2184-201. [PMID: 23339452 PMCID: PMC3629850 DOI: 10.1089/ars.2012.5110] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
SIGNIFICANCE Photosynthetic organisms are subjected to frequent changes in their environment that include fluctuations in light quality and quantity, temperature, CO(2) concentration, and nutrient availability. They have evolved complex responses to these changes that allow them to protect themselves against photo-oxidative damage and to optimize their growth under these adverse conditions. In the case of light changes, these acclimatory processes can occur in either the short or the long term and are mainly mediated through the redox state of the plastoquinone pool and the ferredoxin/thioredoxin system. RECENT ADVANCES Short-term responses involve a dynamic reorganization of photosynthetic complexes, and long-term responses (LTRs) modulate the chloroplast and nuclear gene expression in such a way that the levels of the photosystems and their antennae are rebalanced for an optimal photosynthetic performance. These changes are mediated through a complex signaling network with several protein kinases and phosphatases that are conserved in land plants and algae. The phosphorylation status of the light-harvesting proteins of photosystem II and its core proteins is mainly determined by two complementary kinase-phosphatase pairs corresponding to STN7/PPH1 and STN8/PBCP, respectively. CRITICAL ISSUES The activity of the Stt7 kinase is principally regulated by the redox state of the plastoquinone pool, which in turn depends on the light irradiance, ambient CO(2) concentration, and cellular energy status. In addition, this kinase is also involved in the LTR. FUTURE DIRECTIONS Other chloroplast kinases modulate the activity of the plastid transcriptional machinery, but the global signaling network that connects all of the identified kinases and phosphatases is still largely unknown.
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Affiliation(s)
- Jean-David Rochaix
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland.
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105
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Chae HB, Moon JC, Shin MR, Chi YH, Jung YJ, Lee SY, Nawkar GM, Jung HS, Hyun JK, Kim WY, Kang CH, Yun DJ, Lee KO, Lee SY. Thioredoxin reductase type C (NTRC) orchestrates enhanced thermotolerance to Arabidopsis by its redox-dependent holdase chaperone function. MOLECULAR PLANT 2013; 6:323-36. [PMID: 23024205 DOI: 10.1093/mp/sss105] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Genevestigator analysis has indicated heat shock induction of transcripts for NADPH-thioredoxin reductase, type C (NTRC) in the light. Here we show overexpression of NTRC in Arabidopsis (NTRC°(E)) resulting in enhanced tolerance to heat shock, whereas NTRC knockout mutant plants (ntrc1) exhibit a temperature sensitive phenotype. To investigate the underlying mechanism of this phenotype, we analyzed the protein's biochemical properties and protein structure. NTRC assembles into homopolymeric structures of varying complexity with functions as a disulfide reductase, a foldase chaperone, and as a holdase chaperone. The multiple functions of NTRC are closely correlated with protein structure. Complexes of higher molecular weight (HMW) showed stronger activity as a holdase chaperone, while low molecular weight (LMW) species exhibited weaker holdase chaperone activity but stronger disulfide reductase and foldase chaperone activities. Heat shock converted LMW proteins into HMW complexes. Mutations of the two active site Cys residues of NTRC into Ser (C217/454S-NTRC) led to a complete inactivation of its disulfide reductase and foldase chaperone functions, but conferred only a slight decrease in its holdase chaperone function. The overexpression of the mutated C217/454S-NTRC provided Arabidopsis with a similar degree of thermotolerance compared with that of NTRC°(E) plants. However, after prolonged incubation under heat shock, NTRC°(E) plants tolerated the stress to a higher degree than C217/454S-NTRC°(E) plants. The results suggest that the heat shock-mediated holdase chaperone function of NTRC is responsible for the increased thermotolerance of Arabidopsis and the activity is significantly supported by NADPH.
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Affiliation(s)
- Ho Byoung Chae
- Division of Applied Life Science (BK21 Program) and PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju 660-701, Korea
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106
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Ma W, Ying YL, Qin LX, Gu Z, Zhou H, Li DW, Sutherland TC, Chen HY, Long YT. Investigating electron-transfer processes using a biomimetic hybrid bilayer membrane system. Nat Protoc 2013; 8:439-50. [PMID: 23391888 DOI: 10.1038/nprot.2013.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Here we report a protocol to investigate the electron-transfer processes of redox-active biomolecules in biological membranes by electrochemistry using biomimetic hybrid bilayer membranes (HBMs) assembled on gold electrodes. Redox-active head groups, such as the ubiquinone moiety, are embedded in HBMs that contain target molecules, e.g., nicotinamide adenine dinucleotide (NADH). By using this approach, the electron-transfer processes between redox molecules and target biomolecules are mediated by mimicking the redox cycling processes in a natural membrane. Also included is a procedure for in situ surface-enhanced Raman scattering (SERS) to confirm the electrochemically induced conformational changes of the target biomolecules in the HBMs. In addition, each step in constructing the HBMs is characterized by electrochemical impedance spectroscopy (EIS), high-resolution X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The time required for the entire protocol is ∼12 h, whereas the electrochemical measurement of electron-transfer processes takes less than 1 h to complete.
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Affiliation(s)
- Wei Ma
- State Key Laboratory of Bioreactor Engineering, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, P. R. China
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107
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Thormählen I, Ruber J, von Roepenack-Lahaye E, Ehrlich SM, Massot V, Hümmer C, Tezycka J, Issakidis-Bourguet E, Geigenberger P. Inactivation of thioredoxin f1 leads to decreased light activation of ADP-glucose pyrophosphorylase and altered diurnal starch turnover in leaves of Arabidopsis plants. PLANT, CELL & ENVIRONMENT 2013; 36:16-29. [PMID: 22646759 DOI: 10.1111/j.1365-3040.2012.02549.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Chloroplast thioredoxin f (Trx f) is an important regulator of primary metabolic enzymes. However, genetic evidence for its physiological importance is largely lacking. To test the functional significance of Trx f in vivo, Arabidopsis mutants with insertions in the trx f1 gene were studied, showing a drastic decrease in Trx f leaf content. Knockout of Trx f1 led to strong attenuation in reductive light activation of ADP-glucose pyrophosphorylase (AGPase), the key enzyme of starch synthesis, in leaves during the day and in isolated chloroplasts, while sucrose-dependent redox activation of AGPase in darkened leaves was not affected. The decrease in light-activation of AGPase in leaves was accompanied by a decrease in starch accumulation, an increase in sucrose levels and a decrease in starch-to-sucrose ratio. Analysis of metabolite levels at the end of day shows that inhibition of starch synthesis was unlikely due to shortage of substrates or changes in allosteric effectors. Metabolite profiling by gas chromatography-mass spectrometry pinpoints only a small number of metabolites affected, including sugars, organic acids and ethanolamine. Interestingly, metabolite data indicate carbon shortage in trx f1 mutant leaves at the end of night. Overall, results provide in planta evidence for the role played by Trx f in the light activation of AGPase and photosynthetic carbon partitioning in plants.
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Affiliation(s)
- Ina Thormählen
- Department Biologie I, Metabolism Group Mass-Spectrometry Group, Ludwig-Maximilians-Universität München, Martinsried, Germany
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108
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Terry MJ, Smith AG. A model for tetrapyrrole synthesis as the primary mechanism for plastid-to-nucleus signaling during chloroplast biogenesis. FRONTIERS IN PLANT SCIENCE 2013; 4:14. [PMID: 23407626 PMCID: PMC3570980 DOI: 10.3389/fpls.2013.00014] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 01/20/2013] [Indexed: 05/18/2023]
Abstract
Chloroplast biogenesis involves the co-ordinated expression of the chloroplast and nuclear genomes, requiring information to be sent from the developing chloroplasts to the nucleus. This is achieved through retrograde signaling pathways and can be demonstrated experimentally using the photobleaching herbicide, norflurazon, which in seedlings results in chloroplast damage and the reduced expression of many photosynthesis-related, nuclear genes. Genetic analysis of this pathway points to a major role for tetrapyrrole synthesis in retrograde signaling, as well as a strong interaction with light signaling pathways. Currently, the best model to explain the genetic data is that a specific heme pool generated by flux through ferrochelatase-1 functions as a positive signal to promote the expression of genes required for chloroplast development. We propose that this heme-related signal is the primary positive signal during chloroplast biogenesis, and that treatments and mutations affecting chloroplast transcription, RNA editing, translation, or protein import all impact on the synthesis and/or processing of this signal. A positive signal is consistent with the need to provide information on chloroplast status at all times. We further propose that GUN1 normally serves to restrict the production of the heme signal. In addition to a positive signal re-enforcing chloroplast development under normal conditions, aberrant chloroplast development may produce a negative signal due to accumulation of unbound chlorophyll biosynthesis intermediates, such as Mg-porphyrins. Under these conditions a rapid shut-down of tetrapyrrole synthesis is required. We propose that accumulation of these intermediates results in a rapid light-dependent inhibition of nuclear gene expression that is most likely mediated via singlet oxygen generated by photo-excitation of Mg-porphyrins. Thus, the tetrapyrrole pathway may provide both positive and inhibitory signals to control expression of nuclear genes.
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Affiliation(s)
- Matthew J. Terry
- Centre for Biological Sciences, University of SouthamptonSouthampton, UK
- Institute for Life Sciences, University of SouthamptonSouthampton, UK
- *Correspondence: Matthew J. Terry, Centre for Biological Sciences, University of Southampton, Life Sciences Building 85, Highfield Campus, Southampton SO17 1BJ, UK. e-mail:
| | - Alison G. Smith
- Department of Plant Sciences, University of CambridgeCambridge, UK
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109
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Regulation of Leaf Senescence: Role of Reactive Oxygen Species. PLASTID DEVELOPMENT IN LEAVES DURING GROWTH AND SENESCENCE 2013. [DOI: 10.1007/978-94-007-5724-0_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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110
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Ren M, Venglat P, Qiu S, Feng L, Cao Y, Wang E, Xiang D, Wang J, Alexander D, Chalivendra S, Logan D, Mattoo A, Selvaraj G, Datla R. Target of rapamycin signaling regulates metabolism, growth, and life span in Arabidopsis. THE PLANT CELL 2012; 24:4850-74. [PMID: 23275579 PMCID: PMC3556962 DOI: 10.1105/tpc.112.107144] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Target of Rapamycin (TOR) is a major nutrition and energy sensor that regulates growth and life span in yeast and animals. In plants, growth and life span are intertwined not only with nutrient acquisition from the soil and nutrition generation via photosynthesis but also with their unique modes of development and differentiation. How TOR functions in these processes has not yet been determined. To gain further insights, rapamycin-sensitive transgenic Arabidopsis thaliana lines (BP12) expressing yeast FK506 Binding Protein12 were developed. Inhibition of TOR in BP12 plants by rapamycin resulted in slower overall root, leaf, and shoot growth and development leading to poor nutrient uptake and light energy utilization. Experimental limitation of nutrient availability and light energy supply in wild-type Arabidopsis produced phenotypes observed with TOR knockdown plants, indicating a link between TOR signaling and nutrition/light energy status. Genetic and physiological studies together with RNA sequencing and metabolite analysis of TOR-suppressed lines revealed that TOR regulates development and life span in Arabidopsis by restructuring cell growth, carbon and nitrogen metabolism, gene expression, and rRNA and protein synthesis. Gain- and loss-of-function Ribosomal Protein S6 (RPS6) mutants additionally show that TOR function involves RPS6-mediated nutrition and light-dependent growth and life span in Arabidopsis.
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Affiliation(s)
- Maozhi Ren
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Prakash Venglat
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Shuqing Qiu
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Li Feng
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Yongguo Cao
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Edwin Wang
- Computational Chemistry and Bioinformatics Group, Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec H4P 2R2, Canada
| | - Daoquan Xiang
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Jinghe Wang
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | | | | | - David Logan
- Université d’Angers, Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, LUNAM Université, Angers cedex 1, France
| | - Autar Mattoo
- Sustainable Agricultural Systems Laboratory, U.S. Department of Agriculture–Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, Maryland 20705-2350
| | - Gopalan Selvaraj
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Raju Datla
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
- Address correspondence to
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111
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Schwarz C, Bohne AV, Wang F, Cejudo FJ, Nickelsen J. An intermolecular disulfide-based light switch for chloroplast psbD gene expression in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 72:378-89. [PMID: 22725132 DOI: 10.1111/j.1365-313x.2012.05083.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Expression of the chloroplast psbD gene encoding the D2 protein of the photosystem II reaction center is regulated by light. In the green alga Chlamydomonas reinhardtii, D2 synthesis requires a high-molecular-weight complex containing the RNA stabilization factor Nac2 and the translational activator RBP40. Based on size exclusion chromatography analyses, we provide evidence that light control of D2 synthesis depends on dynamic formation of the Nac2/RBP40 complex. Furthermore, 2D redox SDS-PAGE assays suggest an intermolecular disulfide bridge between Nac2 and Cys11 of RBP40 as the putative molecular basis for attachment of RBP40 to the complex in light-grown cells. This covalent link is reduced in the dark, most likely via NADPH-dependent thioredoxin reductase C, supporting the idea of a direct relationship between chloroplast gene expression and chloroplast carbon metabolism during dark adaption of algal cells.
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Affiliation(s)
- Christian Schwarz
- Molekulare Pflanzenwissenschaften, Biozentrum Ludwig Maximilian University Munich, Grosshaderner Strasse, Planegg-Martinsried, Germany
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112
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Bohrer AS, Massot V, Innocenti G, Reichheld JP, Issakidis-Bourguet E, Vanacker H. New insights into the reduction systems of plastidial thioredoxins point out the unique properties of thioredoxin z from Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:6315-6323. [PMID: 23096001 DOI: 10.1093/jxb/ers283] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In plants, thioredoxins (TRX) constitute a large protein disulphide oxidoreductase family comprising 10 plastidial members in Arabidopsis thaliana and subdivided in five types. The f- and m-types regulate enzymes involved mainly in carbon metabolism whereas the x, y, and z types have an antioxidant function. The reduction of TRXm and f in chloroplasts is performed in the light by ferredoxin:thioredoxin reductase (FTR) that uses photosynthetically reduced ferredoxin (Fd) as a reductant. The reduction system of Arabidopsis TRXx, y, and z has never been demonstrated. Recently, a gene encoding an atypical plastidial NADPH-dependent TRX reductase (NTRC) was found. In the present study, gene expression analysis revealed that both reductases are expressed in all organs of Arabidopsis and could potentially serve as electron donors to plastidial TRX. This ability was tested in vitro either with purified NTRC in presence of NADPH or with a light-driven reconstituted system comprising thylakoids and purified Fd and FTR. The results demonstrate that FTR reduces the x and y TRX isoforms but not the recently identified TRXz. Moreover, the results show that NTRC cannot be an efficient alternative reducing system, neither for TRXz nor for the other plastidial TRX. The data reveal that TRXf, m, x, and y, known as redox regulators in the chloroplast, have also the ability to reduce TRXz in vitro. Overall, the present study points out the unique properties of TRXz among plastidial TRX.
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Affiliation(s)
- Anne-Sophie Bohrer
- Institut de Biologie des Plantes, UMR CNRS 8618, Saclay Plant Sciences, Univ Paris-Sud, 91405, Orsay cedex, France
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113
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Chen C, Zhang D, Li P, Ma F. Partitioning of absorbed light energy differed between the sun-exposed side and the shaded side of apple fruits under high light conditions. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 60:12-17. [PMID: 22892330 DOI: 10.1016/j.plaphy.2012.07.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 07/20/2012] [Indexed: 06/01/2023]
Abstract
Fractions of absorbed light energy consumed via photochemistry and different thermal dissipation processes was quantified and compared between the sun-exposed peel and the shaded peel of apple fruits at different developmental stages. During fruit development, the fraction of absorbed light consumed via photochemistry was no more than 7% in the sun-exposed peel and no more than 5% in the shaded peel under high light conditions. Under high light, the fraction of absorbed light energy consumed via light dependent thermal dissipation was higher whereas that via constitutive thermal dissipation was lower in the sun-exposed peel. The light dependent thermal dissipation in the sun-exposed peel mainly depended on the xanthophyll cycle, and the xanthophyll cycle pool size was significantly larger in the sun-exposed peel than in the shaded peel. The light dependent thermal dissipation in the shaded peel was dependent on both the xanthophyll cycle and the presence of inactivated reaction centers. Under high light conditions, the densities of both Q(A)-reducing reaction centers and Q(B)-reducing reaction centers decreased faster in the shaded peel than in the sun-exposed peel. The thermal dissipation related to photoinhibition increased and then kept unchanged in the sun-exposed peel but decreased in the shaded peel during fruit development. We conclude that under high light intensities, fruit peel looses the excess energy in order of predominance: first by the xanthophyll cycle, then the thermal dissipation related to photoinhibition, next through inactivated reaction centers, and finally by constitutive thermal dissipation.
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Affiliation(s)
- Changsheng Chen
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi 712100, China
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114
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Meyer Y, Belin C, Delorme-Hinoux V, Reichheld JP, Riondet C. Thioredoxin and glutaredoxin systems in plants: molecular mechanisms, crosstalks, and functional significance. Antioxid Redox Signal 2012; 17:1124-60. [PMID: 22531002 DOI: 10.1089/ars.2011.4327] [Citation(s) in RCA: 225] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Thioredoxins (Trx) and glutaredoxins (Grx) constitute families of thiol oxidoreductases. Our knowledge of Trx and Grx in plants has dramatically increased during the last decade. The release of the Arabidopsis genome sequence revealed an unexpectedly high number of Trx and Grx genes. The availability of several genomes of vascular and nonvascular plants allowed the establishment of a clear classification of the genes and the chronology of their appearance during plant evolution. Proteomic approaches have been developed that identified the putative Trx and Grx target proteins which are implicated in all aspects of plant growth, including basal metabolism, iron/sulfur cluster formation, development, adaptation to the environment, and stress responses. Analyses of the biochemical characteristics of specific Trx and Grx point to a strong specificity toward some target enzymes, particularly within plastidial Trx and Grx. In apparent contradiction with this specificity, genetic approaches show an absence of phenotype for most available Trx and Grx mutants, suggesting that redundancies also exist between Trx and Grx members. Despite this, the isolation of mutants inactivated in multiple genes and several genetic screens allowed the demonstration of the involvement of Trx and Grx in pathogen response, phytohormone pathways, and at several control points of plant development. Cytosolic Trxs are reduced by NADPH-thioredoxin reductase (NTR), while the reduction of Grx depends on reduced glutathione (GSH). Interestingly, recent development integrating biochemical analysis, proteomic data, and genetics have revealed an extensive crosstalk between the cytosolic NTR/Trx and GSH/Grx systems. This crosstalk, which occurs at multiple levels, reveals the high plasticity of the redox systems in plants.
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Affiliation(s)
- Yves Meyer
- Laboratoire Génome et Développement des Plantes, Université de Perpignan, Perpignan, France
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115
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Cooke JEK, Eriksson ME, Junttila O. The dynamic nature of bud dormancy in trees: environmental control and molecular mechanisms. PLANT, CELL & ENVIRONMENT 2012; 35:1707-28. [PMID: 22670814 DOI: 10.1111/j.1365-3040.2012.02552.x] [Citation(s) in RCA: 304] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
In tree species native to temperate and boreal regions, the activity-dormancy cycle is an important adaptive trait both for survival and growth. We discuss recent research on mechanisms controlling the overlapping developmental processes that define the activity-dormancy cycle, including cessation of apical growth, bud development, induction, maintenance and release of dormancy, and bud burst. The cycle involves an extensive reconfiguration of metabolism. Environmental control of the activity-dormancy cycle is based on perception of photoperiodic and temperature signals, reflecting adaptation to prevailing climatic conditions. Several molecular actors for control of growth cessation have been identified, with the CO/FT regulatory network and circadian clock having important coordinating roles in control of growth and dormancy. Other candidate regulators of bud set, dormancy and bud burst have been identified, such as dormancy-associated MADS-box factors, but their exact roles remain to be discovered. Epigenetic mechanisms also appear to factor in control of the activity-dormancy cycle. Despite evidence for gibberellins as negative regulators in growth cessation, and ABA and ethylene in bud formation, understanding of the roles that plant growth regulators play in controlling the activity-dormancy cycle is still very fragmentary. Finally, some of the challenges for further research in bud dormancy are discussed.
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Affiliation(s)
- Janice E K Cooke
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
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116
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Brzezowski P, Wilson KE, Gray GR. The PSBP2 protein of Chlamydomonas reinhardtii is required for singlet oxygen-dependent signaling. PLANTA 2012; 236:1289-1303. [PMID: 22718311 DOI: 10.1007/s00425-012-1683-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 05/30/2012] [Indexed: 06/01/2023]
Abstract
In the green alga Chlamydomonas reinhardtii, the cytosolic Glutathione Peroxidase 5 gene (GPX5) is known to be transcriptionally up-regulated in response to singlet oxygen ((1)O(2)). As demonstrated by previous studies, fusion of the promoter region of GPX5 to the Arylsulfatase 2 gene (ARS2) creates an effective reporter system that can be used to monitor (1)O(2)-driven GPX5 expression. This system was also used in this study to generate a stably transformed C. reinhardtii strain which expresses ARS2 in a (1)O(2)-dependent manner, resulting in the synthesis of a functional protein with detectable activity. Using the strain of C. reinhardtii harboring a (1)O(2)-sensitive reporter construct, a secondary mutagenic screen was performed. This allowed identification of mutant cell lines that were unable to up-regulate expression of the GPX5-ARS2 fusion in response to (1)O(2). In one of these lines, the mutation was subsequently localized to the first exon of the PSBP-like gene (PSBP2). The PSBP2 gene is part of a small protein family in C. reinhardtii, also present in all angiosperms studied thus far. While each member of the PSBP protein family contains a similar domain to the PSBP1 protein, which is a member of the oxygen evolving complex of photosystem II (PSII), the PSBP2 protein does not appear to be involved in PSII function, but may function as a sensor and/or signal mediating molecule of the (1)O(2) generated in the chloroplast.
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Affiliation(s)
- Pawel Brzezowski
- Department of Biology, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
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117
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De Marchis F, Pompa A, Bellucci M. Plastid proteostasis and heterologous protein accumulation in transplastomic plants. PLANT PHYSIOLOGY 2012; 160:571-81. [PMID: 22872774 PMCID: PMC3461539 DOI: 10.1104/pp.112.203778] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
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118
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Pfannschmidt T, Yang C. The hidden function of photosynthesis: a sensing system for environmental conditions that regulates plant acclimation responses. PROTOPLASMA 2012; 249 Suppl 2:S125-36. [PMID: 22441589 DOI: 10.1007/s00709-012-0398-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 03/12/2012] [Indexed: 05/03/2023]
Abstract
Plants convert light energy from the sun into chemical energy by photosynthesis. Since they are sessile, they have to deal with a wide range of conditions in their immediate environment. Many abiotic and biotic parameters exhibit considerable fluctuations which can have detrimental effects especially on the efficiency of photosynthetic light harvesting. During evolution, plants, therefore, evolved a number of acclimation processes which help them to adapt photosynthesis to such environmental changes. This includes protective mechanisms such as excess energy dissipation and processes supporting energy redistribution, e.g. state transitions or photosystem stoichiometry adjustment. Intriguingly, all these responses are triggered by photosynthesis itself via the interplay of its light reaction and the Calvin-Benson cycle with the residing environmental condition. Thus, besides its primary function in harnessing and converting light energy, photosynthesis acts as a sensing system for environmental changes that controls molecular acclimation responses which adapt the photosynthetic function to the environmental change. Important signalling parameters directly or indirectly affected by the environment are the pH gradient across the thylakoid membrane and the redox states of components of the photosynthetic electron transport chain and/or electron end acceptors coupled to it. Recent advances demonstrate that these signals control post-translational modifications of the photosynthetic protein complexes and also affect plastid and nuclear gene expression machineries as well as metabolic pathways providing a regulatory framework for an integrated response of the plant to the environment at all cellular levels.
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Affiliation(s)
- Thomas Pfannschmidt
- Junior Research Group Plant Acclimation To Environmental Changes, Protein Analysis by MS, Department of Plant Physiology, Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str 159, 07743 Jena, Germany.
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119
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Dangoor I, Peled-Zehavi H, Wittenberg G, Danon A. A chloroplast light-regulated oxidative sensor for moderate light intensity in Arabidopsis. THE PLANT CELL 2012; 24:1894-906. [PMID: 22570442 PMCID: PMC3442576 DOI: 10.1105/tpc.112.097139] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The transition from dark to light involves marked changes in the redox reactions of photosynthetic electron transport and in chloroplast stromal enzyme activity even under mild light and growth conditions. Thus, it is not surprising that redox regulation is used to dynamically adjust and coordinate the stromal and thylakoid compartments. While oxidation of regulatory proteins is necessary for the regulation, the identity and the mechanism of action of the oxidizing pathway are still unresolved. Here, we studied the oxidation of a thylakoid-associated atypical thioredoxin-type protein, ACHT1, in the Arabidopsis thaliana chloroplast. We found that after a brief period of net reduction in plants illuminated with moderate light intensity, a significant oxidation reaction of ACHT1 arises and counterbalances its reduction. Interestingly, ACHT1 oxidation is driven by 2-Cys peroxiredoxin (Prx), which in turn eliminates peroxides. The ACHT1 and 2-Cys Prx reaction characteristics in plants further indicated that ACHT1 oxidation is linked with changes in the photosynthetic production of peroxides. Our findings that plants with altered redox poise of the ACHT1 and 2-Cys Prx pathway show higher nonphotochemical quenching and lower photosynthetic electron transport infer a feedback regulatory role for this pathway.
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120
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Luo T, Fan T, Liu Y, Rothbart M, Yu J, Zhou S, Grimm B, Luo M. Thioredoxin redox regulates ATPase activity of magnesium chelatase CHLI subunit and modulates redox-mediated signaling in tetrapyrrole biosynthesis and homeostasis of reactive oxygen species in pea plants. PLANT PHYSIOLOGY 2012; 159:118-30. [PMID: 22452855 PMCID: PMC3375955 DOI: 10.1104/pp.112.195446] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 03/23/2012] [Indexed: 05/20/2023]
Abstract
The chloroplast thioredoxins (TRXs) function as messengers of redox signals from ferredoxin to target enzymes. In this work, we studied the regulatory impact of pea (Pisum sativum) TRX-F on the magnesium (Mg) chelatase CHLI subunit and the enzymatic activation of Mg chelatase in vitro and in vivo. In vitro, reduced TRX-F activated the ATPase activity of pea CHLI and enhanced the activity of Mg chelatase reconstituted from the three recombinant subunits CHLI, CHLD, and CHLH in combination with the regulator protein GENOMES UNCOUPLED4 (GUN4). Yeast two-hybrid and bimolecular fluorescence complementation assays demonstrated that TRX-F physically interacts with CHLI but not with either of the other two subunits or GUN4. In vivo, virus-induced TRX-F gene silencing (VIGS-TRX-F) in pea plants did not result in an altered redox state of CHLI. However, simultaneous silencing of the pea TRX-F and TRX-M genes (VIGS-TRX-F/TRX-M) resulted in partially and fully oxidized CHLI in vivo. VIGS-TRX-F/TRX-M plants demonstrated a significant reduction in Mg chelatase activity and 5-aminolevulinic acid synthesizing capacity as well as reduced pigment content and lower photosynthetic capacity. These results suggest that, in vivo, TRX-M can compensate for a lack of TRX-F and that both TRXs act as important redox regulators of Mg chelatase. Furthermore, the silencing of TRX-F and TRX-M expression also affects gene expression in the tetrapyrrole biosynthesis pathway and leads to the accumulation of reactive oxygen species, which may also serve as an additional signal for the transcriptional regulation of photosynthesis-associated nuclear genes.
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Affiliation(s)
- Tao Luo
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, People′s Republic of China (T.L., T.F., Y.L., J.Y., S.Z., M.L.); and Institute of Biology/Plant Physiology, Humboldt University, D–10115 Berlin, Germany (T.L., M.R., B.G.)
| | - Tingting Fan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, People′s Republic of China (T.L., T.F., Y.L., J.Y., S.Z., M.L.); and Institute of Biology/Plant Physiology, Humboldt University, D–10115 Berlin, Germany (T.L., M.R., B.G.)
| | - Yinan Liu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, People′s Republic of China (T.L., T.F., Y.L., J.Y., S.Z., M.L.); and Institute of Biology/Plant Physiology, Humboldt University, D–10115 Berlin, Germany (T.L., M.R., B.G.)
| | - Maxi Rothbart
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, People′s Republic of China (T.L., T.F., Y.L., J.Y., S.Z., M.L.); and Institute of Biology/Plant Physiology, Humboldt University, D–10115 Berlin, Germany (T.L., M.R., B.G.)
| | - Jing Yu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, People′s Republic of China (T.L., T.F., Y.L., J.Y., S.Z., M.L.); and Institute of Biology/Plant Physiology, Humboldt University, D–10115 Berlin, Germany (T.L., M.R., B.G.)
| | - Shuaixiang Zhou
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, People′s Republic of China (T.L., T.F., Y.L., J.Y., S.Z., M.L.); and Institute of Biology/Plant Physiology, Humboldt University, D–10115 Berlin, Germany (T.L., M.R., B.G.)
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121
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Symbiodinium transcriptomes: genome insights into the dinoflagellate symbionts of reef-building corals. PLoS One 2012; 7:e35269. [PMID: 22529998 PMCID: PMC3329448 DOI: 10.1371/journal.pone.0035269] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Accepted: 03/13/2012] [Indexed: 12/20/2022] Open
Abstract
Dinoflagellates are unicellular algae that are ubiquitously abundant in aquatic environments. Species of the genus Symbiodinium form symbiotic relationships with reef-building corals and other marine invertebrates. Despite their ecologic importance, little is known about the genetics of dinoflagellates in general and Symbiodinium in particular. Here, we used 454 sequencing to generate transcriptome data from two Symbiodinium species from different clades (clade A and clade B). With more than 56,000 assembled sequences per species, these data represent the largest transcriptomic resource for dinoflagellates to date. Our results corroborate previous observations that dinoflagellates possess the complete nucleosome machinery. We found a complete set of core histones as well as several H3 variants and H2A.Z in one species. Furthermore, transcriptome analysis points toward a low number of transcription factors in Symbiodinium spp. that also differ in the distribution of DNA-binding domains relative to other eukaryotes. In particular the cold shock domain was predominant among transcription factors. Additionally, we found a high number of antioxidative genes in comparison to non-symbiotic but evolutionary related organisms. These findings might be of relevance in the context of the role that Symbiodinium spp. play as coral symbionts. Our data represent the most comprehensive dinoflagellate EST data set to date. This study provides a comprehensive resource to further analyze the genetic makeup, metabolic capacities, and gene repertoire of Symbiodinium and dinoflagellates. Overall, our findings indicate that Symbiodinium possesses some unique characteristics, in particular the transcriptional regulation in Symbiodinium may differ from the currently known mechanisms of eukaryotic gene regulation.
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122
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Deeba F, Pandey AK, Ranjan S, Mishra A, Singh R, Sharma YK, Shirke PA, Pandey V. Physiological and proteomic responses of cotton (Gossypium herbaceum L.) to drought stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 53:6-18. [PMID: 22285410 DOI: 10.1016/j.plaphy.2012.01.002] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 01/03/2012] [Indexed: 05/18/2023]
Abstract
Cotton genotype RAHS 187 was analyzed for changes in physiology, biochemistry and proteome due to drought stress. The deleterious effect of drought in cotton plants was mainly targeted towards photosynthesis. The gas-exchange parameters of net photosynthesis (A), stomatal conductance (g(s)) and transpiration (E) showed a decreasing trend as the drought intensity increased. The fluorescence parameters of, effective quantum yield of PSII (Φ(PSII)), and electron transport rates (ETR), also showed a declining trend. As the intensity of drought increased, both H(2)O(2) and MDA levels increased indicating oxidative stress. Anthocyanin levels were increased by more than four folds in the droughted plants. Two-dimensional gel electrophoresis detected more than 550 protein spots. Significantly expressed proteins were analyzed by peptide mass fingerprinting (PMF) using MALDI-TOF-TOF. The number of up-regulated spots was found to be 16 while 6 spots were down-regulated. The reasonable implications in drought response of the identified proteins vis-à-vis physiological changes are discussed. Results provide some additional information that can lead to a better understanding of the molecular basis of drought-sensitivity in cotton plants.
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Affiliation(s)
- Farah Deeba
- Plant Physiology Lab, Council of Scientific and Industrial Research - National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001, U.P., India
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Foyer CH, Neukermans J, Queval G, Noctor G, Harbinson J. Photosynthetic control of electron transport and the regulation of gene expression. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:1637-61. [PMID: 22371324 DOI: 10.1093/jxb/ers013] [Citation(s) in RCA: 273] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The term 'photosynthetic control' describes the short- and long-term mechanisms that regulate reactions in the photosynthetic electron transport (PET) chain so that the rate of production of ATP and NADPH is coordinated with the rate of their utilization in metabolism. At low irradiances these mechanisms serve to optimize light use efficiency, while at high irradiances they operate to dissipate excess excitation energy as heat. Similarly, the production of ATP and NADPH in ratios tailored to meet demand is finely tuned by a sophisticated series of controls that prevents the accumulation of high NAD(P)H/NAD(P) ratios and ATP/ADP ratios that would lead to potentially harmful over-reduction and inactivation of PET chain components. In recent years, photosynthetic control has also been extrapolated to the regulation of gene expression because mechanisms that are identical or similar to those that serve to regulate electron flow through the PET chain also coordinate the regulated expression of genes encoding photosynthetic proteins. This requires coordinated gene expression in the chloroplasts, mitochondria, and nuclei, involving complex networks of forward and retrograde signalling pathways. Photosynthetic control operates to control photosynthetic gene expression in response to environmental and metabolic changes. Mining literature data on transcriptome profiles of C(3) and C(4) leaves from plants grown under high atmospheric carbon dioxide (CO(2)) levels compared with those grown with ambient CO(2) reveals that the transition to higher photorespiratory conditions in C(3) plants enhances the expression of genes associated with cyclic electron flow pathways in Arabidopsis thaliana, consistent with the higher ATP requirement (relative to NADPH) of photorespiration.
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Affiliation(s)
- Christine H Foyer
- Centre for Plant Sciences, Faculty of Biology, University of Leeds, Leeds LS2 9JT, UK.
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Hackenberg C, Huege J, Engelhardt A, Wittink F, Laue M, Matthijs HCP, Kopka J, Bauwe H, Hagemann M. Low-carbon acclimation in carboxysome-less and photorespiratory mutants of the cyanobacterium Synechocystis sp. strain PCC 6803. Microbiology (Reading) 2012; 158:398-413. [DOI: 10.1099/mic.0.054544-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- Claudia Hackenberg
- Universität Rostock, Institut für Biowissenschaften, Pflanzenphysiologie, Albert-Einstein-Str. 3, D-18059 Rostock, Germany
| | - Jan Huege
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Golm, Germany
| | - Annerose Engelhardt
- Universität Rostock, Institut für Biowissenschaften, Pflanzenphysiologie, Albert-Einstein-Str. 3, D-18059 Rostock, Germany
| | - Floyd Wittink
- Microarray Department, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
| | - Michael Laue
- Universität Rostock, Institut für Pathologie, Elektronenmikroskopisches Zentrum, Strempelstr. 14, D-18055 Rostock, Germany
| | - Hans C. P. Matthijs
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
| | - Joachim Kopka
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Golm, Germany
| | - Hermann Bauwe
- Universität Rostock, Institut für Biowissenschaften, Pflanzenphysiologie, Albert-Einstein-Str. 3, D-18059 Rostock, Germany
| | - Martin Hagemann
- Universität Rostock, Institut für Biowissenschaften, Pflanzenphysiologie, Albert-Einstein-Str. 3, D-18059 Rostock, Germany
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Scheibe R, Dietz KJ. Reduction-oxidation network for flexible adjustment of cellular metabolism in photoautotrophic cells. PLANT, CELL & ENVIRONMENT 2012; 35:202-16. [PMID: 21410714 DOI: 10.1111/j.1365-3040.2011.02319.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Photosynthesis generates the energy carriers NADPH and ATP to be consumed in assimilatory processes. Continuous energy conversion and optimal use of the available light energy are only guaranteed when all reduction-oxidation (redox) processes are tightly controlled. A robust network links metabolism with regulation and signalling. Information on the redox situation is generated and transferred by various redox components that are parts of this network. Any imbalance in the network is sensed, and the information is transmitted in order to elicit a response at the various levels of regulation and in the different cellular compartments. Redox information within the chloroplast is derived from intersystem electron transport, the ferredoxin-NADP oxidoreductase (FNR)/NADPH branch of the redox network, the thioredoxin branch and from reactive oxygen species (ROS), resulting in a high diversity of responses that are able to adjust photosynthesis, as well as poising and antioxidant systems accordingly in each specific situation. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) represents a central step in CO(2) reduction and in carbohydrate oxidation involving both forms of energy, namely NAD(P)H and ATP, with its various isoforms that are located in plastids, cytosol and nucleus. GAPDH is used as an example to demonstrate complexity, flexibility and robustness of the regulatory redox network in plants.
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Affiliation(s)
- Renate Scheibe
- Plant Physiology, University of Osnabrueck, 49069 Osnabrueck, Germany
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León P, Gregorio J, Cordoba E. ABI4 and its role in chloroplast retrograde communication. FRONTIERS IN PLANT SCIENCE 2012; 3:304. [PMID: 23335930 PMCID: PMC3541689 DOI: 10.3389/fpls.2012.00304] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 12/18/2012] [Indexed: 05/17/2023]
Abstract
The acquisition of plastids is a landmark event in plant evolution. The proper functionality of these organelles depends on strict and continuous communication between the plastids and the nucleus to precisely adjust gene expression in response to the organelle's requirements. Signals originating from the plastids impact the expression of a variety of nuclear genes, and this retrograde communication is essential to couple the nuclear expression of plastid-localized products with organelle gene expression and, ultimately, functionality. Major advances have been made in this field over the past few years with the characterization of independent retrograde signaling pathways and the identification of some of their components. One such factor is the nuclear transcriptional factor ABI4 (ABA-INSENTIVE 4). ABI4, together with the plastid PPR GUN1 protein, has been proposed to function as a node of convergence for multiple plastid retrograde signaling pathways. ABI4 is conserved among plants and also plays important roles in various critical developmental and metabolic processes. ABI4 is a versatile regulator that positively and negatively modulates the expression of many genes, including other transcriptional factors. However, its mode of action during plastid retrograde signaling is not fully understood. In this review, we describe the current evidence that supports the participation of ABI4 in different retrograde communication pathways. ABI4 is regulated at the transcriptional and post-transcriptional level. A known regulator of ABI4 includes the PTM transcription factor, which moves from the chloroplast to the nucleus. This transcription factor is a candidate for the transmission of retrograde signals between the plastid and ABI4.
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Affiliation(s)
- Patricia León
- *Correspondence: Patricia León, Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Colonia Chamilpa, Cuernavaca, Morelos 62210, México. e-mail:
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127
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Pfalz J, Liebers M, Hirth M, Grübler B, Holtzegel U, Schröter Y, Dietzel L, Pfannschmidt T. Environmental control of plant nuclear gene expression by chloroplast redox signals. FRONTIERS IN PLANT SCIENCE 2012; 3:257. [PMID: 23181068 PMCID: PMC3500774 DOI: 10.3389/fpls.2012.00257] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Accepted: 11/01/2012] [Indexed: 05/20/2023]
Abstract
Plant photosynthesis takes place in specialized cell organelles, the chloroplasts, which perform all essential steps of this process. The proteins involved in photosynthesis are encoded by genes located on the plastid and nuclear genomes. Proper function and regulation of light harvesting and energy fixation thus requires a tight coordination of the gene expression machineries in the two genetic compartments. This is achieved by a bi-directional exchange of information between nucleus and plastids. Signals emerging from plastids report the functional and developmental state of the organelle to the nucleus and initiate distinct nuclear gene expression profiles, which trigger responses that support or improve plastid functions. Recent research indicated that this signaling is absolutely essential for plant growth and development. Reduction/oxidation (redox) signals from photosynthesis are key players in this information network since they do report functional disturbances in photosynthesis, the primary energy source of plants. Such disturbances are caused by environmental fluctuations for instance in illumination, temperature, or water availability. These environmental changes affect the linear electron flow of photosynthesis and result in changes of the redox state of the components involved [e.g., the plastoquinone (PQ) pool] or coupled to it (e.g., the thioredoxin pool). Thus, the changes in redox state directly reflect the environmental impact and serve as immediate plastidial signals to the nucleus. The triggered responses range from counterbalancing reactions within the physiological range up to severe stress responses including cell death. This review focuses on physiological redox signals from photosynthetic electron transport (PET), their relation to the environment, potential transduction pathways to the nucleus and their impact on nuclear gene expression.
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Affiliation(s)
| | | | | | | | | | | | | | - Thomas Pfannschmidt
- *Correspondence: Thomas Pfannschmidt, Department of Plant Physiology, Institute of General Botany and Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743 Jena, Germany. e-mail:
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Sharma S, Villamor JG, Verslues PE. Essential role of tissue-specific proline synthesis and catabolism in growth and redox balance at low water potential. PLANT PHYSIOLOGY 2011; 157:292-304. [PMID: 21791601 PMCID: PMC3165878 DOI: 10.1104/pp.111.183210] [Citation(s) in RCA: 192] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 07/25/2011] [Indexed: 05/18/2023]
Abstract
To better define the still unclear role of proline (Pro) metabolism in drought resistance, we analyzed Arabidopsis (Arabidopsis thaliana) Δ(1)-pyrroline-5-carboxylate synthetase1 (p5cs1) mutants deficient in stress-induced Pro synthesis as well as proline dehydrogenase (pdh1) mutants blocked in Pro catabolism and found that both Pro synthesis and catabolism were required for optimal growth at low water potential (ψ(w)). The abscisic acid (ABA)-deficient mutant aba2-1 had similar reduction in root elongation as p5cs1 and p5cs1/aba2-1 double mutants. However, the reduced growth of aba2-1 but not p5cs1/aba2-1 could be complemented by exogenous ABA, indicating that Pro metabolism was required for ABA-mediated growth protection at low ψ(w). PDH1 maintained high expression in the root apex and shoot meristem at low ψ(w) rather than being repressed, as in the bulk of the shoot tissue. This, plus a reduced oxygen consumption and buildup of Pro in the root apex of pdh1-2, indicated that active Pro catabolism was needed to sustain growth at low ψ(w). Conversely, P5CS1 expression was most highly induced in shoot tissue. Both p5cs1-4 and pdh1-2 had a more reduced NADP/NADPH ratio than the wild type at low ψ(w). These results indicate a new model of Pro metabolism at low ψ(w) whereby Pro synthesis in the photosynthetic tissue regenerates NADP while Pro catabolism in meristematic and expanding cells is needed to sustain growth. Tissue-specific differences in Pro metabolism and function in maintaining a favorable NADP/NADPH ratio are relevant to understanding metabolic adaptations to drought and efforts to enhance drought resistance.
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Affiliation(s)
| | | | - Paul E. Verslues
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
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Tovar-Méndez A, Matamoros MA, Bustos-Sanmamed P, Dietz KJ, Cejudo FJ, Rouhier N, Sato S, Tabata S, Becana M. Peroxiredoxins and NADPH-dependent thioredoxin systems in the model legume Lotus japonicus. PLANT PHYSIOLOGY 2011; 156:1535-47. [PMID: 21562331 PMCID: PMC3131139 DOI: 10.1104/pp.111.177196] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 05/06/2011] [Indexed: 05/08/2023]
Abstract
Peroxiredoxins (Prxs), thioredoxins (Trxs), and NADPH-thioredoxin reductases (NTRs) constitute central elements of the thiol-disulfide redox regulatory network of plant cells. This study provides a comprehensive survey of this network in the model legume Lotus japonicus. The aims were to identify and characterize these gene families and to assess whether the NTR-Trx systems are operative in nodules. Quantitative reverse transcription-polymerase chain reaction and immunological and proteomic approaches were used for expression profiling. We identified seven Prx, 14 Trx, and three NTR functional genes. The PrxQ1 gene was found to be transcribed in two alternative spliced variants and to be expressed at high levels in leaves, stems, petals, pods, and seeds and at low levels in roots and nodules. The 1CPrx gene showed very high expression in the seed embryos and low expression in vegetative tissues and was induced by nitric oxide and cytokinins. In sharp contrast, cytokinins down-regulated all other Prx genes, except PrxQ1, in roots and nodules, but only 2CPrxA and PrxQ1 in leaves. Gene-specific changes in Prx expression were also observed in response to ethylene, abscisic acid, and auxins. Nodules contain significant mRNA and protein amounts of cytosolic PrxIIB, Trxh1, and NTRA and of plastidic NTRC. Likewise, they express cytosolic Trxh3, Trxh4, Trxh8, and Trxh9, mitochondrial PrxIIF and Trxo, and plastidic Trxm2, Trxm4, and ferredoxin-Trx reductase. These findings reveal a complex regulation of Prxs that is dependent on the isoform, tissue, and signaling molecule and support that redox NTR-Trx systems are functional in the cytosol, mitochondria, and plastids of nodules.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Manuel Becana
- Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, 50080 Zaragoza, Spain (A.T.-M., M.A.M., P.B.-S., M.B.); Biochemistry and Physiology of Plants, Bielefeld University, 33501 Bielefeld, Germany (K.-J.D.); Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla y Consejo Superior de Investigaciones Científicas, 41092 Seville, Spain (F.J.C.); UMR Interactions Arbres Microorganismes 1136, Nancy Université, 54506 Vandoeuvre, France (N.R.); Kazusa DNA Research Institute, Kisarazu, Chiba 292–0818, Japan (S.S., S.T.)
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130
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van Wijk KJ, Baginsky S. Plastid proteomics in higher plants: current state and future goals. PLANT PHYSIOLOGY 2011; 155:1578-88. [PMID: 21350036 PMCID: PMC3091083 DOI: 10.1104/pp.111.172932] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 02/21/2011] [Indexed: 05/18/2023]
Affiliation(s)
- Klaas J van Wijk
- Department of Plant Biology, Cornell University, Ithaca, New York 14853, USA.
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