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Lin S, Liu Z, Sun S, Xue F, Li H, Tursun A, Cao L, Zhang L, Wilson ZA, Zhang D, Liang W. Rice HEAT SHOCK PROTEIN60-3B maintains male fertility under high temperature by starch granule biogenesis. PLANT PHYSIOLOGY 2023; 192:2301-2317. [PMID: 36861636 PMCID: PMC10315285 DOI: 10.1093/plphys/kiad136] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/18/2023] [Accepted: 01/29/2023] [Indexed: 06/18/2023]
Abstract
Heat stress has a deleterious effect on male fertility in rice (Oryza sativa), but mechanisms to protect against heat stress in rice male gametophytes are poorly understood. Here, we have isolated and characterized a heat-sensitive male-sterile rice mutant, heat shock protein60-3b (oshsp60-3b), that shows normal fertility at optimal temperatures but decreasing fertility as temperatures increase. High temperatures interfered with pollen starch granule formation and reactive oxygen species (ROS) scavenging in oshsp60-3b anthers, leading to cell death and pollen abortion. In line with the mutant phenotypes, OsHSP60-3B was rapidly upregulated in response to heat shock and its protein products were localized to the plastid. Critically, overexpression of OsHSP60-3B enhanced the heat tolerance of pollen in transgenic plants. We demonstrated that OsHSP60-3B interacted with FLOURY ENDOSPERM6(FLO6) in plastids, a key component involved in the starch granule formation in the rice pollen. Western blot results showed that FLO6 level was substantially decreased in oshsp60-3b anthers at high temperature, indicating that OsHSP60-3B is required to stabilize FLO6 when temperatures exceed optimal conditions. We suggest that in response to high temperature, OsHSP60-3B interacts with FLO6 to regulate starch granule biogenesis in rice pollen and attenuates ROS levels in anthers to ensure normal male gametophyte development in rice.
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Affiliation(s)
- Sen Lin
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ze Liu
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shiyu Sun
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Feiyang Xue
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Huanjun Li
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Askar Tursun
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lichun Cao
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Long Zhang
- Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou 225009, China
| | - Zoe A Wilson
- Division of Plant & Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, UK
| | - Dabing Zhang
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, Australia
| | - Wanqi Liang
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
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Li J, Kong D, Song T, Hu Z, Li Q, Xiao B, Kessler F, Zhang Z, Xie G. OsFBN7-OsKAS I module promotes formation of plastoglobules clusters in rice chloroplasts. THE NEW PHYTOLOGIST 2023. [PMID: 37366020 DOI: 10.1111/nph.19081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 05/29/2023] [Indexed: 06/28/2023]
Abstract
Plastoglobules (PGs) contiguous with the outer leaflets of thylakoid membranes regulate lipid metabolism, plastid developmental transitions, and responses to environmental stimuli. However, the function of OsFBN7, a PG-core fibrillin gene in rice, has not been elucidated. Using molecular genetics and physiobiochemical approaches, we observed that OsFBN7 overexpression promoted PG clustering in rice chloroplasts. OsFBN7 interacted with two KAS I enzymes, namely OsKAS Ia and OsKAS Ib, in rice chloroplasts. Lipidomic analysis of chloroplast subcompartments, including PGs in the OsFBN7 overexpression lines, confirmed that levels of diacylglycerol (DAG), a chloroplast lipid precursor and monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), the main chloroplast membrane lipids, were increased in PGs and chloroplasts. Furthermore, OsFBN7 enhanced the abundances of OsKAS Ia/Ib in planta and their stability under oxidative and heat stresses. In addition, RNA sequencing and real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analyses showed that the expression of the DAG synthetase gene PAP1 and MGDG synthase gene MDG2 was upregulated by OsFBN7. In conclusion, this study proposes a new model in which OsFBN7 binds to OsKAS Ia/Ib in chloroplast and enhances their abundance and stability, thereby regulating the chloroplast and PG membrane lipids involved in the formation of PG clusters.
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Affiliation(s)
- Jiajia Li
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Dongyan Kong
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ting Song
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhenzhu Hu
- College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qiang Li
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Benze Xiao
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Felix Kessler
- Laboratory of Plant Physiology, University of Neuchatel, Neuchatel, 2000, Switzerland
| | - Zhengfeng Zhang
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, China
| | - Guosheng Xie
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
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Chen J. A starch- and ROS-regulating heat shock protein helps maintain male fertility in heat-stressed rice plants. PLANT PHYSIOLOGY 2023:kiad217. [PMID: 37052180 DOI: 10.1093/plphys/kiad217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/14/2023] [Accepted: 04/11/2023] [Indexed: 06/19/2023]
Affiliation(s)
- Jiawen Chen
- Assistant Features Editor, Plant Physiology, American Society of Plant Biologists, USA
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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Lin MT, Salihovic H, Clark FK, Hanson MR. Improving the efficiency of Rubisco by resurrecting its ancestors in the family Solanaceae. SCIENCE ADVANCES 2022; 8:eabm6871. [PMID: 35427154 PMCID: PMC9012466 DOI: 10.1126/sciadv.abm6871] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Plants and photosynthetic organisms have a remarkably inefficient enzyme named Rubisco that fixes atmospheric CO2 into organic compounds. Understanding how Rubisco has evolved in response to past climate change is important for attempts to adjust plants to future conditions. In this study, we developed a computational workflow to assemble de novo both large and small subunits of Rubisco enzymes from transcriptomics data. Next, we predicted sequences for ancestral Rubiscos of the (nightshade) family Solanaceae and characterized their kinetics after coexpressing them in Escherichia coli. Predicted ancestors of C3 Rubiscos were identified that have superior kinetics and excellent potential to help plants adapt to anthropogenic climate change. Our findings also advance understanding of the evolution of Rubisco's catalytic traits.
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Hotto AM, Salesse-Smith C, Lin M, Busch FA, Simpson I, Stern DB. Rubisco production in maize mesophyll cells through ectopic expression of subunits and chaperones. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4930-4937. [PMID: 33928359 DOI: 10.1093/jxb/erab189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/26/2021] [Indexed: 06/12/2023]
Abstract
C4 plants, such as maize, strictly compartmentalize Rubisco to bundle sheath chloroplasts. The molecular basis for the restriction of Rubisco from the more abundant mesophyll chloroplasts is not fully understood. Mesophyll chloroplasts transcribe the Rubisco large subunit gene and, when normally quiescent transcription of the nuclear Rubisco small subunit gene family is overcome by ectopic expression, mesophyll chloroplasts still do not accumulate measurable Rubisco. Here we show that a combination of five ubiquitin promoter-driven nuclear transgenes expressed in maize leads to mesophyll accumulation of assembled Rubisco. These encode the Rubisco large and small subunits, Rubisco assembly factors 1 and 2, and the assembly factor Bundle sheath defective 2. In these plants, Rubisco large subunit accumulates in mesophyll cells, and appears to be assembled into a holoenzyme capable of binding the substrate analog CABP (carboxyarabinitol bisphosphate). Isotope discrimination assays suggest, however, that mesophyll Rubisco is not participating in carbon assimilation in these plants, most probably due to a lack of the substrate ribulose 1,5-bisphosphate and/or Rubisco activase. Overall, this work defines a minimal set of Rubisco assembly factors in planta and may help lead to methods of regulating the C4 pathway.
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Affiliation(s)
| | | | - Myat Lin
- Cornell University, Ithaca, NY, USA
| | - Florian A Busch
- School of Biosciences, and Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, Birmingham, UK
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
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Nagaraju M, Kumar A, Jalaja N, Rao DM, Kishor PBK. Functional Exploration of Chaperonin (HSP60/10) Family Genes and their Abiotic Stress-induced Expression Patterns in Sorghum bicolor. Curr Genomics 2021; 22:137-152. [PMID: 34220300 PMCID: PMC8188580 DOI: 10.2174/1389202922666210324154336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 01/05/2021] [Accepted: 01/22/2021] [Indexed: 11/30/2022] Open
Abstract
Background Sorghum, the C4 dry-land cereal, important for food, fodder, feed and fuel, is a model crop for abiotic stress tolerance with smaller genome size, genetic diversity, and bio-energy traits. The heat shock proteins/chaperonin 60s (HSP60/Cpn60s) assist the plastid proteins, and participate in the folding and aggregation of proteins. However, the functions of HSP60s in abiotic stress tolerance in Sorghum remain unclear. Methods Genome-wide screening and in silico characterization of SbHSP60s were carried out along with tissue and stress-specific expression analysis. Results A total of 36 HSP60 genes were identified in Sorghum bicolor. They were subdivided into 2 groups, the HSP60 and HSP10 co-chaperonins encoded by 30 and 6 genes, respectively. The genes are distributed on all the chromosomes, chromosome 1 being the hot spot with 9 genes. All the HSP60s were found hydrophilic and highly unstable. The HSP60 genes showed a large number of introns, the majority of them with more than 10. Among the 12 paralogs, only 1 was tandem and the remaining 11 segmental, indicating their role in the expansion of SbHSP60s. Majority of the SbHSP60 genes expressed uniformly in leaf while a moderate expression was observed in the root tissues, with the highest expression displayed by SbHSP60-1. From expression analysis, SbHSP60-3 for drought, SbHSP60-9 for salt, SbHSP60-9 and 24 for heat and SbHSP60-3, 9 and SbHSP10-2 have been found implicated for cold stress tolerance and appeared as the key regulatory genes. Conclusion This work paves the way for the utilization of chaperonin family genes for achieving abiotic stress tolerance in plants.
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Affiliation(s)
- M Nagaraju
- Department of Genetics, Osmania University, Hyderabad 500 007, India.,Biochemistry Division, National Institute of Nutrition (ICMR), Hyderabad 500 007, India
| | - Anuj Kumar
- Advance Center for Computational & Applied Biotechnology, Uttarakhand Council for Biotechnology (UCB), Silk Park, Prem Nagar, Dehradun 248 007, India
| | - N Jalaja
- Department of Biotechnology, Vignan's Foundation for Science, Technology and Research, Vadlamudi, Guntur 522 213, Andhra Pradesh, India
| | - D Manohar Rao
- Department of Genetics, Osmania University, Hyderabad 500 007, India
| | - P B Kavi Kishor
- Department of Biotechnology, Vignan's Foundation for Science, Technology and Research, Vadlamudi, Guntur 522 213, Andhra Pradesh, India
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Ye J, Chen W, Feng L, Liu G, Wang Y, Li H, Ye Z, Zhang Y. The chaperonin 60 protein SlCpn60α1 modulates photosynthesis and photorespiration in tomato. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:7224-7240. [PMID: 32915204 DOI: 10.1093/jxb/eraa418] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/08/2020] [Indexed: 06/11/2023]
Abstract
Photosynthesis, an indispensable biological process of plants, produces organic substances for plant growth, during which photorespiration occurs to oxidize carbohydrates to achieve homeostasis. Although the molecular mechanism underlying photosynthesis and photorespiration has been widely explored, the crosstalk between the two processes remains largely unknown. In this study, we isolated and characterized a T-DNA insertion mutant of tomato (Solanum lycopersicum) named yellow leaf (yl) with yellowish leaves, retarded growth, and chloroplast collapse that hampered both photosynthesis and photorespiration. Genetic and expression analyses demonstrated that the phenotype of yl was caused by a loss-of-function mutation resulting from a single-copy T-DNA insertion in chaperonin 60α1 (SlCPN60α1). SlCPN60α1 showed high expression levels in leaves and was located in both chloroplasts and mitochondria. Silencing of SlCPN60α1using virus-induced gene silencing and RNA interference mimicked the phenotype of yl. Results of two-dimensional electrophoresis and yeast two-hybrid assays suggest that SlCPN60α1 potentially interacts with proteins that are involved in chlorophyll synthesis, photosynthetic electron transport, and the Calvin cycle, and further affect photosynthesis. Moreover, SlCPN60α1 directly interacted with serine hydroxymethyltransferase (SlSHMT1) in mitochondria, thereby regulating photorespiration in tomato. This study outlines the importance of SlCPN60α1 for both photosynthesis and photorespiration, and provides molecular insights towards plant genetic improvement.
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Affiliation(s)
- Jie Ye
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, USA
| | - Weifang Chen
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Longwei Feng
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Genzhong Liu
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Ying Wang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Hanxia Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Zhibiao Ye
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
| | - Yuyang Zhang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, China
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Klasek L, Inoue K, Theg SM. Chloroplast Chaperonin-Mediated Targeting of a Thylakoid Membrane Protein. THE PLANT CELL 2020; 32:3884-3901. [PMID: 33093145 PMCID: PMC7721336 DOI: 10.1105/tpc.20.00309] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/11/2020] [Accepted: 10/21/2020] [Indexed: 05/08/2023]
Abstract
Posttranslational protein targeting requires chaperone assistance to direct insertion-competent proteins to integration pathways. Chloroplasts integrate nearly all thylakoid transmembrane proteins posttranslationally, but mechanisms in the stroma that assist their insertion remain largely undefined. Here, we investigated how the chloroplast chaperonin (Cpn60) facilitated the thylakoid integration of Plastidic type I signal peptidase 1 (Plsp1) using in vitro targeting assays. Cpn60 bound Plsp1 in the stroma. In isolated chloroplasts, the membrane integration of imported Plsp1 correlated with its dissociation from Cpn60. When the Plsp1 residues that interacted with Cpn60 were removed, Plsp1 did not integrate into the membrane. These results suggested Cpn60 was an intermediate in thylakoid targeting of Plsp1. In isolated thylakoids, the integration of Plsp1 decreased when Cpn60 was present in excess of cpSecA1, the stromal motor of the cpSec1 translocon that inserts unfolded Plsp1 into the thylakoid. An excess of cpSecA1 favored integration. Introducing Cpn60's obligate substrate RbcL displaced Cpn60-bound Plsp1; then, the released Plsp1 exhibited increased accessibility to cpSec1. These in vitro targeting experiments support a model in which Cpn60 captures and then releases insertion-competent Plsp1, whereas cpSecA1 recognizes free Plsp1 for integration. Thylakoid transmembrane proteins in the stroma can interact with Cpn60 to shield themselves from the aqueous environment.
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Affiliation(s)
- Laura Klasek
- Department of Plant Biology, University of California Davis, Davis, California 95616
| | - Kentaro Inoue
- Department of Plant Sciences, University of California Davis, Davis, California 95616
| | - Steven M Theg
- Department of Plant Biology, University of California Davis, Davis, California 95616
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Bertoni G. Hold Me, Fold Me...or Not! THE PLANT CELL 2020; 32:3654-3655. [PMID: 33093142 PMCID: PMC7721318 DOI: 10.1105/tpc.20.00881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
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Poonia AK, Mishra SK, Sirohi P, Chaudhary R, Kanwar M, Germain H, Chauhan H. Overexpression of wheat transcription factor (TaHsfA6b) provides thermotolerance in barley. PLANTA 2020; 252:53. [PMID: 32945950 DOI: 10.1007/s00425-020-03457-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 08/28/2020] [Indexed: 05/22/2023]
Abstract
Overexpressing a heat shock factor gene (TaHsfA6bT) from wheat provides thermotolerance in barley by constitutive expression of heat and other abiotic stress-response genes. Temperature is one of the most crucial abiotic factors defining the yield potential of temperate cereal crops, such as barley. The regulators of heat shock response (HSR), heat stress transcription factors (Hsfs), modulate the transcription level of heat-responsive genes to protect the plants from heat stress. In this study, an Hsf from wheat (TaHsfA6b) is overexpressed in barley for providing thermotolerance. Transgenic barley lines overexpressing TaHsfA6b showed improvement in thermotolerance. The constitutive overexpression of a TaHsfA6b gene upregulated the expression of major heat shock proteins and other abiotic stress-responsive genes. RNA-seq and qRT-PCR analysis confirmed the upregulation of Hsps, chaperonins, DNAJ, LEA protein genes, and genes related to anti-oxidative enzymes in transgenic lines. Excessive generation and accumulation of reactive oxygen species (ROS) occurred in wild-type (WT) plants during heat stress; however, the transgenic lines reflected improved ROS homeostasis mechanisms, showing lesser ROS accumulation under high temperature. No negative phenotypic changes were observed in overexpression lines. These results suggest that TaHsfA6b is a regulator of HSR and its overexpression altered the expression patterns of some main stress-related genes and enhanced the thermotolerance of this cereal crop.
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Affiliation(s)
- Anuj Kumar Poonia
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Sumit Kumar Mishra
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Parul Sirohi
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
- Department of Chemistry, Biochemistry and Physics, Université du Québec à Trois-Rivières, Trois-Rivières, QC, G9A 5H7, Canada
| | - Reeku Chaudhary
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Meenakshi Kanwar
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Hugo Germain
- Department of Chemistry, Biochemistry and Physics, Université du Québec à Trois-Rivières, Trois-Rivières, QC, G9A 5H7, Canada
| | - Harsh Chauhan
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India.
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OsCpn60β1 is Essential for Chloroplast Development in Rice ( Oryza sativa L.). Int J Mol Sci 2020; 21:ijms21114023. [PMID: 32512821 PMCID: PMC7313468 DOI: 10.3390/ijms21114023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 01/03/2023] Open
Abstract
The chaperonin 60 (Cpn60) protein is of great importance to plants due to its involvement in modulating the folding of numerous chloroplast protein polypeptides. In chloroplasts, Cpn60 is differentiated into two subunit types—Cpn60α and Cpn60β and the rice genome encodes three α and three β plastid chaperonin subunits. However, the functions of Cpn60 family members in rice were poorly understood. In order to investigate the molecular mechanism of OsCpn60β1, we attempted to disrupt the OsCpn60β1 gene by CRISPR/Cas9-mediated targeted mutagenesis in this study. We succeeded in the production of homozygous OsCpn60β1 knockout rice plants. The OsCpn60β1 mutant displayed a striking albino leaf phenotype and was seedling lethal. Electron microscopy observation demonstrated that chloroplasts were severely disrupted in the OsCpn60β1 mutant. In addition, OsCpn60β1 was located in the chloroplast and OsCpn60β1 is constitutively expressed in various tissues particularly in the green tissues. The label-free qualitative proteomics showed that photosynthesis-related pathways and ribosomal pathways were significantly inhibited in OsCpn60β1 mutants. These results indicate that OsCpn60β1 is essential for chloroplast development in rice.
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Huang WL, Wu FL, Huang HY, Huang WT, Deng CL, Yang LT, Huang ZR, Chen LS. Excess Copper-Induced Alterations of Protein Profiles and Related Physiological Parameters in Citrus Leaves. PLANTS (BASEL, SWITZERLAND) 2020; 9:E291. [PMID: 32121140 PMCID: PMC7154894 DOI: 10.3390/plants9030291] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 02/23/2020] [Accepted: 02/24/2020] [Indexed: 01/31/2023]
Abstract
This present study examined excess copper (Cu) effects on seedling growth, leaf Cu concentration, gas exchange, and protein profiles identified by a two-dimensional electrophoresis (2-DE) based mass spectrometry (MS) approach after Citrus sinensis and Citrus grandis seedlings were treated for six months with 0.5 (control), 200, 300, or 400 μM CuCl2. Forty-one and 37 differentially abundant protein (DAP) spots were identified in Cu-treated C. grandis and C. sinensis leaves, respectively, including some novel DAPs that were not reported in leaves and/or roots. Most of these DAPs were identified only in C. grandis or C. sinensis leaves. More DAPs increased in abundances than DAPs decreased in abundances were observed in Cu-treated C. grandis leaves, but the opposite was true in Cu-treated C. sinensis leaves. Over 50% of DAPs were associated with photosynthesis, carbohydrate, and energy metabolism. Cu-toxicity-induced reduction in leaf CO2 assimilation might be caused by decreased abundances of proteins related to photosynthetic electron transport chain (PETC) and CO2 assimilation. Cu-effects on PETC were more pronounced in C. sinensis leaves than in C. grandis leaves. DAPs related to antioxidation and detoxification, protein folding and assembly (viz., chaperones and folding catalysts), and signal transduction might be involved in Citrus Cu-toxicity and Cu-tolerance.
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Affiliation(s)
- Wei-Lin Huang
- Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (W.-L.H.); (F.-L.W.); (H.-Y.H.); (W.-T.H.); (L.-T.Y.)
| | - Feng-Lin Wu
- Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (W.-L.H.); (F.-L.W.); (H.-Y.H.); (W.-T.H.); (L.-T.Y.)
| | - Hui-Yu Huang
- Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (W.-L.H.); (F.-L.W.); (H.-Y.H.); (W.-T.H.); (L.-T.Y.)
| | - Wei-Tao Huang
- Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (W.-L.H.); (F.-L.W.); (H.-Y.H.); (W.-T.H.); (L.-T.Y.)
| | - Chong-Ling Deng
- Guangxi Key Laboratory of Citrus Biology, Guangxi Academy of Specialty Crops, Guilin 541004, China; (C.-L.D.); (Z.-R.H.)
| | - Lin-Tong Yang
- Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (W.-L.H.); (F.-L.W.); (H.-Y.H.); (W.-T.H.); (L.-T.Y.)
| | - Zeng-Rong Huang
- Guangxi Key Laboratory of Citrus Biology, Guangxi Academy of Specialty Crops, Guilin 541004, China; (C.-L.D.); (Z.-R.H.)
| | - Li-Song Chen
- Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (W.-L.H.); (F.-L.W.); (H.-Y.H.); (W.-T.H.); (L.-T.Y.)
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- The Higher Education Key Laboratory of Fujian Province for Soil Ecosystem Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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A Systematic View Exploring the Role of Chloroplasts in Plant Abiotic Stress Responses. BIOMED RESEARCH INTERNATIONAL 2019; 2019:6534745. [PMID: 31396532 PMCID: PMC6668530 DOI: 10.1155/2019/6534745] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 06/17/2019] [Accepted: 06/19/2019] [Indexed: 11/18/2022]
Abstract
Chloroplasts are intracellular semiautonomous organelles central to photosynthesis and are essential for plant growth and yield. The significance of the function of chloroplast-related genes in response to climate change has not been well studied in crops. In the present study, the initial focus was on genes that were predicted to be located in the chloroplast genome in rice, a model crop plant, with genes either preferentially expressed in the leaf or ubiquitously expressed in all organs. The characteristics were analyzed by Gene Ontology (GO) enrichment and MapMan functional classification tools. It was then identified that 110 GO terms (45 for leaf expression and 65 for ubiquitous expression) and 1,695 genes mapped to MapMan overviews were strongly associated with chloroplasts. In particular, the MapMan cellular response overview revealed a close association between heat stress response and chloroplast-related genes in rice. Moreover, features of these genes in response to abiotic stress were analyzed using a large-scale publicly available transcript dataset. Consequently, the expression of 215 genes was found to be upregulated in response to high temperature stress. Conversely, genes that responded to other stresses were extremely limited. In other words, chloroplast-related genes were found to affect abiotic stress response mainly through high temperature response, with little effect on response to drought and salinity stress. These results suggest that genes involved in diurnal rhythm in the leaves participate in the reaction to recognize temperature changes in the environment. Furthermore, the predicted protein–protein interaction network analysis associated with high temperature stress is expected to provide a very important basis for the study of molecular mechanisms by which chloroplasts will respond to future climate changes.
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Li LQ, Lyu CC, Li JH, Tong Z, Lu YF, Wang XY, Ni S, Yang SM, Zeng FC, Lu LM. Physiological Analysis and Proteome Quantification of Alligator Weed Stems in Response to Potassium Deficiency Stress. Int J Mol Sci 2019; 20:ijms20010221. [PMID: 30626112 PMCID: PMC6337362 DOI: 10.3390/ijms20010221] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/26/2018] [Accepted: 12/27/2018] [Indexed: 02/06/2023] Open
Abstract
The macronutrient potassium is essential to plant growth, development and stress response. Alligator weed (Alternanthera philoxeroides) has a high tolerance to potassium deficiency (LK) stress. The stem is the primary organ responsible for transporting molecules from the underground root system to the aboveground parts of the plant. However, proteomic changes in response to LK stress are largely unknown in alligator weed stems. In this study, we investigated the physiological and proteomic changes in alligator weed stems under LK stress. First, the chlorophyll and soluble protein content and SOD and POD activity were significantly altered after 15 days of LK treatment. The quantitative proteomic analysis suggested that a total of 296 proteins were differentially abundant proteins (DAPs). The functional annotation analysis revealed that LK stress elicited complex proteomic alterations that were involved in oxidative phosphorylation, plant-pathogen interactions, glycolysis/gluconeogenesis, sugar metabolism, and transport in stems. The subcellular locations analysis suggested 104 proteins showed chloroplastic localization, 81 proteins showed cytoplasmic localization and 40 showed nuclear localization. The protein–protein interaction analysis revealed that 56 proteins were involved in the interaction network, including 9 proteins involved in the ribosome network and 9 in the oxidative phosphorylation network. Additionally, the expressed changes of 5 DAPs were similar between the proteomic quantification analysis and the PRM-MS analysis, and the expression levels of eight genes that encode DAPs were further verified using an RT-qPCR analysis. These results provide valuable information on the adaptive mechanisms in alligator weed stems under LK stress and facilitate the development of efficient strategies for genetically engineering potassium-tolerant crops.
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Affiliation(s)
- Li-Qin Li
- College of Agronomy, Sichuan Agriculture University, Chengdu 611130, China.
| | - Cheng-Cheng Lyu
- College of Agronomy, Sichuan Agriculture University, Chengdu 611130, China.
| | - Jia-Hao Li
- College of Agronomy, Sichuan Agriculture University, Chengdu 611130, China.
| | - Zhu Tong
- College of Agronomy, Sichuan Agriculture University, Chengdu 611130, China.
| | - Yi-Fei Lu
- College of Agronomy, Sichuan Agriculture University, Chengdu 611130, China.
| | - Xi-Yao Wang
- College of Agronomy, Sichuan Agriculture University, Chengdu 611130, China.
| | - Su Ni
- College of Agronomy, Sichuan Agriculture University, Chengdu 611130, China.
| | - Shi-Min Yang
- College of Agronomy, Sichuan Agriculture University, Chengdu 611130, China.
| | - Fu-Chun Zeng
- College of Agronomy, Sichuan Agriculture University, Chengdu 611130, China.
| | - Li-Ming Lu
- College of Agronomy, Sichuan Agriculture University, Chengdu 611130, China.
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Fukayama H, Mizumoto A, Ueguchi C, Katsunuma J, Morita R, Sasayama D, Hatanaka T, Azuma T. Expression level of Rubisco activase negatively correlates with Rubisco content in transgenic rice. PHOTOSYNTHESIS RESEARCH 2018; 137:465-474. [PMID: 29846871 DOI: 10.1007/s11120-018-0525-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 05/25/2018] [Indexed: 05/24/2023]
Abstract
The relationship between ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and Rubisco activase (Rca) levels was studied using transgenic rice overexpressing maize Rca (OX-mRca) and knockdown transgenic rice expressing antisense Rca (KD-Rca). The ratio of Rubisco to total soluble protein was lower in OX-mRca, whereas it was higher in KD-Rca than in WT, indicating that Rca expression was negatively correlated with Rubisco content. The expressions of other Calvin-Benson-Bassham cycle enzymes such as sedoheptulose-1,7-bisphosphatase and phosphoribulokinase analyzed by immunoblotting did not show such a negative correlation with Rca, suggesting that the effect of Rca on protein expression may be specific for Rubisco. Although Rubisco content was decreased in OX-mRca, the transcript levels of the Rubisco large subunit (OsRbcL) and the Rubisco small subunit mostly increased in OX-mRca as well as in KD-Rca. Additionally, polysome loading of OsRbcL was slightly higher in OX-mRca than it was in WT, suggesting that the OsRbcL translation activity was likely stimulated by overexpression of Rca. 35S-methionine labeling experiments demonstrated that there was no significant difference in the stability of newly synthesized Rubisco among genotypes. However, 35S-methionine-labeled Rubisco was marginally decreased in OX-mRca and increased in KD-Rca compared to the WT. These results suggest that Rca negatively affects the Rubisco content, possibly in the synthesis step.
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Affiliation(s)
- Hiroshi Fukayama
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan.
| | - Akina Mizumoto
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Chiaki Ueguchi
- Laboratory of Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Jun Katsunuma
- Laboratory of Crop Science, Faculty of Agriculture, Kobe University, Kobe, 657-8501, Japan
| | - Ryutaro Morita
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Daisuke Sasayama
- Laboratory of Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Tomoko Hatanaka
- Laboratory of Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
| | - Tetsushi Azuma
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan
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Akimoto‐Tomiyama C, Tanabe S, Kajiwara H, Minami E, Ochiai H. Loss of chloroplast-localized protein phosphatase 2Cs in Arabidopsis thaliana leads to enhancement of plant immunity and resistance to Xanthomonas campestris pv. campestris infection. MOLECULAR PLANT PATHOLOGY 2018; 19:1184-1195. [PMID: 28815858 PMCID: PMC6637992 DOI: 10.1111/mpp.12596] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 08/08/2017] [Accepted: 08/12/2017] [Indexed: 05/20/2023]
Abstract
Protein phosphatases (PPs) counteract kinases in reversible phosphorylation events during numerous signal transduction pathways in eukaryotes. PP2Cs, one of the four major classes of the serine/threonine-specific PP family, are greatly expanded in plants. Thus, PP2Cs are thought to play a specific role in signal transduction pathways. Some rice PP2Cs classified in subgroup K are responsive to infection by the compatible Xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight. In Arabidopsis thaliana, orthologous PP2C genes (AtPP2C62 and AtPP2C26) classified to subgroup K are also responsive to Xanthomonas campestris pv. campestris (Xcc, causal agent of black rot) infection. To elucidate the function of these subgroup K PP2Cs, atpp2c62- and atpp2c26-deficient A. thaliana mutants were characterized. A double mutant plant which was inoculated with a compatible Xcc showed reduced lesion development, as well as the suppression of bacterial multiplication. AtPP2C62 and AtPP2C26 localized to the chloroplast. Furthermore, the photosynthesis-related protein, chaperonin-60, was indicated as the potential candidate for the dephosphorylated substrate catalysed by AtPP2C62 and AtPP2C26 using two-dimensional isoelectric focusing sodium dodecylsulfate-polyacrylamide gel electrophoresis (2D-IDF-SDS-PAGE). Taken together, AtPP2C62 and AtPP2C26 are suggested to be involved in both photosynthesis and suppression of the plant immune system. These results imply the occurrence of crosstalk between photosynthesis and the plant defence system to control productivity under pathogen infection.
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Affiliation(s)
- Chiharu Akimoto‐Tomiyama
- Institute of Agrobiological Sciences, National Agriculture and Food Research OrganizationTsukubaIbaraki 305‐8602, Japan
| | - Shigeru Tanabe
- Institute of Agrobiological Sciences, National Agriculture and Food Research OrganizationTsukubaIbaraki 305‐8602, Japan
- Present address:
Sakata Seed CorporationYokohamaJapan
| | - Hideyuki Kajiwara
- Advanced Analysis CenterNational Agriculture and Food Research OrganizationTsukubaIbaraki 305‐8602, Japan
| | - Eiichi Minami
- Institute of Agrobiological Sciences, National Agriculture and Food Research OrganizationTsukubaIbaraki 305‐8602, Japan
| | - Hirokazu Ochiai
- Institute of Agrobiological Sciences, National Agriculture and Food Research OrganizationTsukubaIbaraki 305‐8602, Japan
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17
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Vitlin Gruber A, Feiz L. Rubisco Assembly in the Chloroplast. Front Mol Biosci 2018; 5:24. [PMID: 29594130 PMCID: PMC5859369 DOI: 10.3389/fmolb.2018.00024] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/27/2018] [Indexed: 01/13/2023] Open
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the rate-limiting step in the Calvin-Benson cycle, which transforms atmospheric carbon into a biologically useful carbon source. The slow catalytic rate of Rubisco and low substrate specificity necessitate the production of high levels of this enzyme. In order to engineer a more efficient plant Rubisco, we need to better understand its folding and assembly process. Form I Rubisco, found in green algae and vascular plants, is a hexadecamer composed of 8 large subunits (RbcL), encoded by the chloroplast genome and 8 small, nuclear-encoded subunits (RbcS). Unlike its cyanobacterial homolog, which can be reconstituted in vitro or in E. coli, assisted by bacterial chaperonins (GroEL-GroES) and the RbcX chaperone, biogenesis of functional chloroplast Rubisco requires Cpn60-Cpn20, the chloroplast homologs of GroEL-GroES, and additional auxiliary factors, including Rubisco accumulation factor 1 (Raf1), Rubisco accumulation factor 2 (Raf2) and Bundle sheath defective 2 (Bsd2). The discovery and characterization of these factors paved the way for Arabidopsis Rubisco assembly in E. coli. In the present review, we discuss the uniqueness of hetero-oligomeric chaperonin complex for RbcL folding, as well as the sequential or concurrent actions of the post-chaperonin chaperones in holoenzyme assembly. The exact stages at which each assembly factor functions are yet to be determined. Expression of Arabidopsis Rubisco in E. coli provided some insight regarding the potential roles for Raf1 and RbcX in facilitating RbcL oligomerization, for Bsd2 in stabilizing the oligomeric core prior to holoenzyme assembly, and for Raf2 in interacting with both RbcL and RbcS. In the long term, functional characterization of each known factor along with the potential discovery and characterization of additional factors will set the stage for designing more efficient plants, with a greater biomass, for use in biofuels and sustenance.
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Affiliation(s)
- Anna Vitlin Gruber
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Leila Feiz
- Boyce Thompson Institute, Cornell University, Ithaca, NY, United States
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18
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Vitlin Gruber A, Vugman M, Azem A, Weiss CE. Reconstitution of Pure Chaperonin Hetero-Oligomer Preparations in Vitro by Temperature Modulation. Front Mol Biosci 2018; 5:5. [PMID: 29435453 PMCID: PMC5790771 DOI: 10.3389/fmolb.2018.00005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 01/11/2018] [Indexed: 01/13/2023] Open
Abstract
Chaperonins are large, essential, oligomers that facilitate protein folding in chloroplasts, mitochondria, and eubacteria. Plant chloroplast chaperonins are comprised of multiple homologous subunits that exhibit unique properties. We previously characterized homogeneous, reconstituted, chloroplast-chaperonin oligomers in vitro, each composed of one of three highly homologous beta subunits from A. thaliana. In the current work, we describe alpha-type subunits from the same species and investigate their interaction with β subtypes. Neither alpha subunit was capable of forming higher-order oligomers on its own. When combined with β subunits in the presence of Mg-ATP, only the α2 subunit was able to form stable functional hetero-oligomers, which were capable of refolding denatured protein with native chloroplast co-chaperonins. Since β oligomers were able to oligomerize in the absence of α, we sought conditions under which αβ hetero-oligomers could be produced without contamination of β homo-oligomers. We found that β2 subunits are unable to oligomerize at low temperatures and used this property to obtain homogenous preparations of functional α2β2 hetero-oligomers. The results of this study highlight the importance of reaction conditions such as temperature and concentration for the reconstitution of chloroplast chaperonin oligomers in vitro.
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Affiliation(s)
- Anna Vitlin Gruber
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Milena Vugman
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Abdussalam Azem
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Celeste E Weiss
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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19
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Zhao Q, Liu C. Chloroplast Chaperonin: An Intricate Protein Folding Machine for Photosynthesis. Front Mol Biosci 2018; 4:98. [PMID: 29404339 PMCID: PMC5780408 DOI: 10.3389/fmolb.2017.00098] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 12/28/2017] [Indexed: 11/13/2022] Open
Abstract
Group I chaperonins are large cylindrical-shaped nano-machines that function as a central hub in the protein quality control system in the bacterial cytosol, mitochondria and chloroplasts. In chloroplasts, proteins newly synthesized by chloroplast ribosomes, unfolded by diverse stresses, or translocated from the cytosol run the risk of aberrant folding and aggregation. The chloroplast chaperonin system assists these proteins in folding into their native states. A widely known protein folded by chloroplast chaperonin is the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), an enzyme responsible for the fixation of inorganic CO2 into organic carbohydrates during photosynthesis. Chloroplast chaperonin was initially identified as a Rubisco-binding protein. All photosynthetic eucaryotes genomes encode multiple chaperonin genes which can be divided into α and β subtypes. Unlike the homo-oligomeric chaperonins from bacteria and mitochondria, chloroplast chaperonins are more complex and exists as intricate hetero-oligomers containing both subtypes. The Group I chaperonin requires proper interaction with a detachable lid-like co-chaperonin in the presence of ATP and Mg2+ for substrate encapsulation and conformational transition. Besides the typical Cpn10-like co-chaperonin, a unique co-chaperonin consisting of two tandem Cpn10-like domains joined head-to-tail exists in chloroplasts. Since chloroplasts were proposed as sensors to various environmental stresses, this diversified chloroplast chaperonin system has the potential to adapt to complex conditions by accommodating specific substrates or through regulation at both the transcriptional and post-translational levels. In this review, we discuss recent progress on the unique structure and function of the chloroplast chaperonin system based on model organisms Chlamydomonas reinhardtii and Arabidopsis thaliana. Knowledge of the chloroplast chaperonin system may ultimately lead to successful reconstitution of eukaryotic Rubisco in vitro.
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Affiliation(s)
- Qian Zhao
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Cuimin Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
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20
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Kolesinski P, Rydzy M, Szczepaniak A. Is RAF1 protein from Synechocystis sp. PCC 6803 really needed in the cyanobacterial Rubisco assembly process? PHOTOSYNTHESIS RESEARCH 2017; 132:135-148. [PMID: 28108864 PMCID: PMC5387032 DOI: 10.1007/s11120-017-0336-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/02/2017] [Indexed: 05/29/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is responsible for carbon dioxide conversion during photosynthesis and, therefore, is the most important protein in biomass generation. Modifications of this biocatalyst toward improvements in its properties are hindered by the complicated and not yet fully understood assembly process required for the formation of active holoenzymes. An entire set of auxiliary factors, including chaperonin GroEL/GroES and assembly chaperones RbcX or Rubisco accumulation factor 1 (RAF1), is involved in the folding and subsequent assembly of Rubisco subunits. Recently, it has been shown that cyanobacterial RAF1 acts during the formation of the large Rubisco subunit (RbcL) dimer. However, both its physiological function and its necessity in the prokaryotic Rubisco formation process remain elusive. Here, we demonstrate that the Synechocystis sp. PCC 6803 strain with raf1 gene disruption shows the same growth rate as wild-type cells under standard conditions. Moreover, the Rubisco biosynthesis process seems to be unperturbed in mutant cells despite the absence of RbcL-RAF1 complexes. However, in the tested environmental conditions, sulfur starvation triggers the degradation of RbcL and subsequent proteolysis of other polypeptides in wild-type but not Δraf1 strains. Pull-down experiments also indicate that, apart from Rubisco, RAF1 co-purifies with phycocyanins. We postulate that RAF1 is not an obligatory factor in cyanobacterial Rubisco assembly, but rather participates in environmentally regulated Rubisco homeostasis.
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Affiliation(s)
- Piotr Kolesinski
- Laboratory of Biophysics, Faculty of Biotechnology, University of Wroclaw, F. Joliot-Curie 14a, 50-383, Wroclaw, Poland.
| | - Malgorzata Rydzy
- Laboratory of Biophysics, Faculty of Biotechnology, University of Wroclaw, F. Joliot-Curie 14a, 50-383, Wroclaw, Poland
| | - Andrzej Szczepaniak
- Laboratory of Biophysics, Faculty of Biotechnology, University of Wroclaw, F. Joliot-Curie 14a, 50-383, Wroclaw, Poland
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21
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Li Q, Fang C, Duan Z, Liu Y, Qin H, Zhang J, Sun P, Li W, Wang G, Tian Z. Functional conservation and divergence of GmCHLI genes in polyploid soybean. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 88:584-596. [PMID: 27459730 DOI: 10.1111/tpj.13282] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 07/17/2016] [Accepted: 07/21/2016] [Indexed: 05/15/2023]
Abstract
Polyploidy is prevalent in nature. As the fate of duplicated genes becomes more complicated when the encoded proteins function as oligomers, functional investigations into duplicated oligomer-encoding genes in polyploid genomes will facilitate our understanding of how traits are expressed. In this study, we identified GmCHLI1, a gene encoding the I subunit of magnesium (Mg)-chelatase, which functions in hexamers as responsible for the semi-dominant etiolation phenotype in soybean. Four GmCHLI copies derived from two polyploidy events were identified in the soybean genome. Further investigation with regard to expression patterns indicated that these four copies have diverged into two pairs; mutation in the other copy of the pair that includes GmCHLI1 also resulted in a chlorophyll-deficient phenotype. Protein interaction assays showed that these four GmCHLIs can interact with each other, but stronger interactions were found with mutated subunits. The results indicate that, in polyploidy, deficiency in each copy of duplicated oligomer-encoding genes could result in a mutant phenotype due to hetero-oligomer formation, which is different from the model of allelic dosage or functional redundancy. In addition, we interestingly found an increase in isoflavonoids in the heterozygous etiolated plants, which might be useful for improving soybean seed quality.
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Affiliation(s)
- Qing Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Chao Fang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Zongbiao Duan
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Yucheng Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Hao Qin
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jixiang Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Peng Sun
- Affiliated Hospital of Hebei University, Baoding, 071000, China
| | - Wenbin Li
- Key Laboratory of Soybean Biology in Chinese Ministry of Education, Northeast Agricultural University, Harbin, 150030, China
| | - Guodong Wang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhixi Tian
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
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Xu J, Lan H, Fang H, Huang X, Zhang H, Huang J. Quantitative proteomic analysis of the rice (Oryza sativa L.) salt response. PLoS One 2015; 10:e0120978. [PMID: 25793471 PMCID: PMC4368772 DOI: 10.1371/journal.pone.0120978] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 02/09/2015] [Indexed: 11/19/2022] Open
Abstract
Salt stress is one of most serious limiting factors for crop growth and production. An isobaric Tags for Relative and Absolute Quantitation (iTRAQ) approach was used to analyze proteomic changes in rice shoots under salt stress in this study. A total of 56 proteins were significantly altered and 16 of them were enriched in the pathways of photosynthesis, antioxidant and oxidative phosphorylation. Among these 16 proteins, peroxiredoxin Q and photosystem I subunit D were up-regulated, while thioredoxin M-like, thioredoxin x, thioredoxin peroxidase, glutathione S-transferase F3, PSI subunit H, light-harvesting antenna complex I subunits, chloroplast chaperonin, vacuolar ATP synthase subunit H, and ATP synthase delta chain were down-regulated. Moreover, physiological data including total antioxidant capacity, peroxiredoxin activity, chlorophyll a/b content, glutathione S-transferase activity, reduced glutathione content and ATPase activity were consistent with changes in the levels of these proteins. The levels of the mRNAs encoding these proteins were also analyzed by real-time quantitative reverse transcription PCR, and approximately 86% of the results were consistent with the iTRAQ data. Importantly, our data suggest the important role of PSI in balancing energy supply and ROS generation under salt stress. This study provides information for an improved understanding of the function of photosynthesis and PSI in the salt-stress response of rice.
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Affiliation(s)
- Jianwen Xu
- State key laboratory of crop genetics and germplasm enhancement, Nanjing Agricultural University, Nanjing, 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, 210095, China
| | - Hongxia Lan
- State key laboratory of crop genetics and germplasm enhancement, Nanjing Agricultural University, Nanjing, 210095, China
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Huimin Fang
- State key laboratory of crop genetics and germplasm enhancement, Nanjing Agricultural University, Nanjing, 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, 210095, China
| | - Xi Huang
- State key laboratory of crop genetics and germplasm enhancement, Nanjing Agricultural University, Nanjing, 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, 210095, China
| | - Hongsheng Zhang
- State key laboratory of crop genetics and germplasm enhancement, Nanjing Agricultural University, Nanjing, 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, 210095, China
| | - Ji Huang
- State key laboratory of crop genetics and germplasm enhancement, Nanjing Agricultural University, Nanjing, 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, 210095, China
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Belcher S, Williams-Carrier R, Stiffler N, Barkan A. Large-scale genetic analysis of chloroplast biogenesis in maize. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1004-16. [PMID: 25725436 DOI: 10.1016/j.bbabio.2015.02.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 02/16/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND Chloroplast biogenesis involves a collaboration between several thousand nuclear genes and ~100 genes in the chloroplast. Many of the nuclear genes are of cyanobacterial ancestry and continue to perform their ancestral function. However, many others evolved subsequently and comprise a diverse set of proteins found specifically in photosynthetic eucaryotes. Genetic approaches have been key to the discovery of nuclear genes that participate in chloroplast biogenesis, especially those lacking close homologs outside the plant kingdom. SCOPE OF REVIEW This article summarizes contributions from a genetic resource in maize, the Photosynthetic Mutant Library (PML). The PML collection consists of ~2000 non-photosynthetic mutants induced by Mu transposons. We include a summary of mutant phenotypes for 20 previously unstudied maize genes, including genes encoding chloroplast ribosomal proteins, a PPR protein, tRNA synthetases, proteins involved in plastid transcription, a putative ribosome assembly factor, a chaperonin 60 isoform, and a NifU-domain protein required for Photosystem I biogenesis. MAJOR CONCLUSIONS Insertions in 94 maize genes have been linked thus far to visible and molecular phenotypes with the PML collection. The spectrum of chloroplast biogenesis genes that have been genetically characterized in maize is discussed in the context of related efforts in other organisms. This comparison shows how distinct organismal attributes facilitate the discovery of different gene classes, and reveals examples of functional divergence between monocot and dicot plants. GENERAL SIGNIFICANCE These findings elucidate the biology of an organelle whose activities are fundamental to agriculture and the biosphere. This article is part of a Special Issue entitled: Chloroplast Biogenesis.
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Affiliation(s)
- Susan Belcher
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | | | - Nicholas Stiffler
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
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24
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Feiz L, Williams-Carrier R, Belcher S, Montano M, Barkan A, Stern DB. A protein with an inactive pterin-4a-carbinolamine dehydratase domain is required for Rubisco biogenesis in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 80:862-9. [PMID: 25279696 DOI: 10.1111/tpj.12686] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/15/2014] [Accepted: 09/17/2014] [Indexed: 05/13/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) plays a critical role in sustaining life by catalysis of carbon fixation in the Calvin-Benson pathway. Incomplete knowledge of the assembly pathway of chloroplast Rubisco has hampered efforts to fully delineate the enzyme's properties, or seek improved catalytic characteristics via directed evolution. Here we report that a Mu transposon insertion in the Zea mays (maize) gene encoding a chloroplast dimerization co-factor of hepatocyte nuclear factor 1 (DCoH)/pterin-4α-carbinolamine dehydratases (PCD)-like protein is the causative mutation in a seedling-lethal, Rubisco-deficient mutant named Rubisco accumulation factor 2 (raf2-1). In raf2 mutants newly synthesized Rubisco large subunit accumulates in a high-molecular weight complex, the formation of which requires a specific chaperonin 60-kDa isoform. Analogous observations had been made previously with maize mutants lacking the Rubisco biogenesis proteins RAF1 and BSD2. Chemical cross-linking of maize leaves followed by immunoprecipitation with antibodies to RAF2, RAF1 or BSD2 demonstrated co-immunoprecipitation of each with Rubisco small subunit, and to a lesser extent, co-immunoprecipitation with Rubisco large subunit. We propose that RAF2, RAF1 and BSD2 form transient complexes with the Rubisco small subunit, which in turn assembles with the large subunit as it is released from chaperonins.
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Affiliation(s)
- Leila Feiz
- Boyce Thompson Institute for Plant Research, Cornell University, Tower Road, Ithaca, NY, 14853, USA
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25
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Jiang Q, Mei J, Gong XD, Xu JL, Zhang JH, Teng S, Lin DZ, Dong YJ. Importance of the rice TCD9 encoding α subunit of chaperonin protein 60 (Cpn60α) for the chloroplast development during the early leaf stage. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 215-216:172-9. [PMID: 24388528 DOI: 10.1016/j.plantsci.2013.11.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 11/03/2013] [Accepted: 11/06/2013] [Indexed: 05/05/2023]
Abstract
The chloroplast development governs plant growth and metabolism. This study characterized a novel rice thermo-sensitive chloroplast development 9 (tcd9) mutant, which exhibited the albino phenotype before the 3-leaf stage grown below 24 °C whereas displayed normal green at over 28 °C or even at 20 °C after 5-leaf stage. The obvious decrease in Chl levels, abnormal chloroplasts with few thylakoid lamella and abnormal thylakoids were observed for the albino mutant seedlings at low temperature, but the mutant was apparently normal green at high temperature, suggesting the thermo-sensitivity of albino phenotype. Genetic analysis showed that the albino phenotype was controlled by a single recessive nuclear gene (tcd9). The map-based cloning and molecular complementation tests revealed that the mutation of TCD9 encoding α subunit of Cpn60 protein (Cpn60α), localized in chloroplasts, was responsible for albino phenotype. In addition, TCD9 exhibited the high expression in all tested tissues, especially in young leaves. The transcriptional analysis indicated that all expression levels of the studied genes related to chloroplast development in tcd9 mutant were seriously affected in the albino seedlings at 20 °C, whereas some of them recovered into normal levels in green-seedlings at 32 °C. Our observations suggest that the nuclear-encoded Cpn60α protein TCD9 plays a crucial role in chloroplast development at early leaf stage of rice.
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Affiliation(s)
- Quan Jiang
- Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Jie Mei
- Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Xiao-Di Gong
- Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Jian-Long Xu
- The Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, 12 South Zhong-Guan Cun Street, Beijing 100081, China
| | - Jian-Hui Zhang
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Sheng Teng
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Dong-Zhi Lin
- Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China.
| | - Yan-Jun Dong
- Development Center of Plant Germplasm Resources, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China.
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26
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Vitlin Gruber A, Nisemblat S, Azem A, Weiss C. The complexity of chloroplast chaperonins. TRENDS IN PLANT SCIENCE 2013; 18:688-94. [PMID: 24035661 DOI: 10.1016/j.tplants.2013.08.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 07/29/2013] [Accepted: 08/07/2013] [Indexed: 05/07/2023]
Abstract
Type I chaperonins are large oligomeric protein ensembles that are involved in the folding and assembly of other proteins. Chloroplast chaperonins and co-chaperonins exist in multiple copies of two distinct isoforms that can combine to form a range of labile oligomeric structures. This complex system increases the potential number of chaperonin substrates and possibilities for regulation. The incorporation of unique subunits into the oligomer can modify substrate specificity. Some subunits are upregulated in response to heat shock and some show organ-specific expression, whereas others possess additional functions that are unrelated to their role in protein folding. Accumulating evidence suggests that specific subunits have distinct roles in biogenesis of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco).
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Affiliation(s)
- Anna Vitlin Gruber
- The George S. Wise Faculty of Life Sciences, Department of Biochemistry and Molecular Biology, Tel Aviv University, Ramat Aviv, Israel
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