1
|
López B, Izquierdo Y, Cascón T, Zamarreño ÁM, García-Mina JM, Pulido P, Castresana C. Mutant noxy8 exposes functional specificities between the chloroplast chaperones CLPC1 and CLPC2 in the response to organelle stress and plant defence. PLANT, CELL & ENVIRONMENT 2024; 47:2336-2350. [PMID: 38500380 DOI: 10.1111/pce.14882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 02/20/2024] [Accepted: 03/01/2024] [Indexed: 03/20/2024]
Abstract
Chloroplast function is essential for growth, development, and plant adaptation to stress. Organelle stress and plant defence responses were examined here using noxy8 (nonresponding to oxylipins 8) from a series of Arabidopsis mutants. The noxy8 mutation was located at the CLPC2 gene, encoding a chloroplast chaperone of the protease complex CLP. Although its CLPC1 paralogue is considered to generate redundancy, our data reveal significant differences distinguishing CLPC2 and CLPC1 functions. As such, clpc1 mutants displayed a major defect in housekeeping chloroplast proteostasis, leading to a pronounced reduction in growth and pigment levels, enhanced accumulation of chloroplast and cytosol chaperones, and resistance to fosmidomycin. Conversely, clpc2 mutants showed severe susceptibility to lincomycin inhibition of chloroplast translation and resistance to Antimycin A inhibition of mitochondrial respiration. In the response to Pseudomonas syringae pv. tomato, clpc2 but not clpc1 mutants were resistant to bacterial infection, showing higher salicylic acid levels, defence gene expression and 9-LOX pathway activation. Our findings suggest CLPC2 and CLPC1 functional specificity, with a preferential involvement of CLPC1 in housekeeping processes and of CLPC2 in stress responses.
Collapse
Affiliation(s)
- Bran López
- Centro Nacional de Biotecnología (CNB-CSIC), Cantoblanco, Madrid, Spain
| | - Yovanny Izquierdo
- Centro Nacional de Biotecnología (CNB-CSIC), Cantoblanco, Madrid, Spain
| | - Tomás Cascón
- Centro Nacional de Biotecnología (CNB-CSIC), Cantoblanco, Madrid, Spain
| | - Ángel M Zamarreño
- Department of Environmental Biology, Bioma Institute, University of Navarra, Navarra, Spain
| | - José M García-Mina
- Department of Environmental Biology, Bioma Institute, University of Navarra, Navarra, Spain
| | - Pablo Pulido
- Centro Nacional de Biotecnología (CNB-CSIC), Cantoblanco, Madrid, Spain
| | - Carmen Castresana
- Centro Nacional de Biotecnología (CNB-CSIC), Cantoblanco, Madrid, Spain
| |
Collapse
|
2
|
Sánchez-López ÁM, Bahaji A, Gámez-Arcas S, De Diego N, Vrobel O, Tarkowski P, Baroja-Fernández E, Muñoz FJ, Almagro G, Seguí-Simarro JM, Tabernero-Mendoza M, López-Serrano L, Morcillo RJL, Pozueta-Romero J. PGI1-mediated vascular oxidative pentose phosphate pathway modulates photosynthesis via long-distance cytokinin signaling. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 209:108520. [PMID: 38522131 DOI: 10.1016/j.plaphy.2024.108520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 03/01/2024] [Accepted: 03/09/2024] [Indexed: 03/26/2024]
Abstract
In Arabidopsis, the plastidial isoform of phosphoglucose isomerase, PGI1, mediates growth and photosynthesis, likely due to its involvement in the vascular production of cytokinins (CK). To examine this hypothesis, we characterized pgi1-2 knockout plants impaired in PGI1 and pgi1-2 plants specifically expressing PGI1 in root tips and vascular tissues. Moreover, to investigate whether the phenotype of pgi1-2 plants is due to impairments in the plastidial oxidative pentose phosphate pathway (OPPP) or the glycolytic pathway, we characterized pgl3-1 plants with reduced OPPP and pfk4pfk5 knockout plants impaired in plastidial glycolysis. Compared with wild-type (WT) leaves, pgi1-2 leaves exhibited weaker expression of photosynthesis- and 2-C-methyl-D-erythritol 4-P (MEP) pathway-related proteins, and stronger expression of oxidative stress protection-related enzymes. Consistently, pgi1-2 leaves accumulated lower levels of chlorophyll, and higher levels of tocopherols, flavonols and anthocyanins than the WT. Vascular- and root tip-specific PGI1 expression countered the reduced photosynthesis, low MEP pathway-derived CK content, dwarf phenotype and the metabolic characteristics of pgi1-2 plants, reverting them to WT-like levels. Moreover, pgl3-1, but not pfk4pfk5 plants phenocopied pgi1-2. Histochemical analyses of plants expressing GUS under the control of promoter regions of genes encoding plastidial OPPP enzymes exhibited strong GUS activity in root tips and vascular tissues. Overall, our findings show that root tip and vascular PGI1-mediated plastidial OPPP activity affects photosynthesis and growth through mechanisms involving long-distance modulation of the leaf proteome by MEP pathway-derived CKs.
Collapse
Affiliation(s)
- Ángela María Sánchez-López
- Instituto de Agrobiotecnología (IdAB), CSIC-Gobierno de Navarra, Iruñako etorbidea 123, 31192, Mutiloabeti, Nafarroa, Spain
| | - Abdellatif Bahaji
- Instituto de Agrobiotecnología (IdAB), CSIC-Gobierno de Navarra, Iruñako etorbidea 123, 31192, Mutiloabeti, Nafarroa, Spain.
| | - Samuel Gámez-Arcas
- Instituto de Agrobiotecnología (IdAB), CSIC-Gobierno de Navarra, Iruñako etorbidea 123, 31192, Mutiloabeti, Nafarroa, Spain; Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), CSIC-Universidad de Sevilla, 41092, Sevilla, Spain
| | - Nuria De Diego
- Czech Advanced Technology and Research Institute, Palacky University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Ondřej Vrobel
- Czech Advanced Technology and Research Institute, Palacky University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Petr Tarkowski
- Czech Advanced Technology and Research Institute, Palacky University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Edurne Baroja-Fernández
- Instituto de Agrobiotecnología (IdAB), CSIC-Gobierno de Navarra, Iruñako etorbidea 123, 31192, Mutiloabeti, Nafarroa, Spain
| | - Francisco José Muñoz
- Instituto de Agrobiotecnología (IdAB), CSIC-Gobierno de Navarra, Iruñako etorbidea 123, 31192, Mutiloabeti, Nafarroa, Spain
| | - Goizeder Almagro
- Instituto de Agrobiotecnología (IdAB), CSIC-Gobierno de Navarra, Iruñako etorbidea 123, 31192, Mutiloabeti, Nafarroa, Spain
| | | | | | - Lidia López-Serrano
- Institute for Mediterranean and Subtropical Horticulture "La Mayora" (IHSM), CSIC-UMA, Campus de Teatinos, Avda. Louis Pasteur, 49, 29010, Málaga, Spain
| | - Rafael J L Morcillo
- Institute for Mediterranean and Subtropical Horticulture "La Mayora" (IHSM), CSIC-UMA, Campus de Teatinos, Avda. Louis Pasteur, 49, 29010, Málaga, Spain
| | - Javier Pozueta-Romero
- Instituto de Agrobiotecnología (IdAB), CSIC-Gobierno de Navarra, Iruñako etorbidea 123, 31192, Mutiloabeti, Nafarroa, Spain; Institute for Mediterranean and Subtropical Horticulture "La Mayora" (IHSM), CSIC-UMA, Campus de Teatinos, Avda. Louis Pasteur, 49, 29010, Málaga, Spain.
| |
Collapse
|
3
|
Chen S, Ye M, Kuai P, Chen L, Lou Y. Silencing an ATP-Dependent Caseinolytic Protease Proteolytic Subunit Gene Enhances the Resistance of Rice to Nilaparvata lugens. Int J Mol Sci 2024; 25:3699. [PMID: 38612510 PMCID: PMC11011769 DOI: 10.3390/ijms25073699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/21/2024] [Accepted: 03/21/2024] [Indexed: 04/14/2024] Open
Abstract
The ATP-dependent caseinolytic protease (Clp) system has been reported to play an important role in plant growth, development, and defense against pathogens. However, whether the Clp system is involved in plant defense against herbivores remains largely unclear. We explore the role of the Clp system in rice defenses against brown planthopper (BPH) Nilaparvata lugens by combining chemical analysis, transcriptome, and molecular analyses, as well as insect bioassays. We found the expression of a rice Clp proteolytic subunit gene, OsClpP6, was suppressed by infestation of BPH gravid females and mechanical wounding. Silencing OsClpP6 enhanced the level of BPH-induced jasmonic acid (JA), JA-isoleucine (JA-Ile), and ABA, which in turn promoted the production of BPH-elicited rice volatiles and increased the resistance of rice to BPH. Field trials showed that silencing OsClpP6 decreased the population densities of BPH and WBPH. We also observed that silencing OsClpP6 decreased chlorophyll content in rice leaves at early developmental stages and impaired rice root growth and seed setting rate. These findings demonstrate that an OsClpP6-mediated Clp system in rice was involved in plant growth-defense trade-offs by affecting the biosynthesis of defense-related signaling molecules in chloroplasts. Moreover, rice plants, after recognizing BPH infestation, can enhance rice resistance to BPH by decreasing the Clp system activity. The work might provide a new way to breed rice varieties that are resistant to herbivores.
Collapse
Affiliation(s)
| | | | | | | | - Yonggen Lou
- State Key Laboratory of Rice Breeding and Biology & Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China; (S.C.); (M.Y.); (P.K.); (L.C.)
| |
Collapse
|
4
|
Muñoz-Vargas MA, Taboada J, González-Gordo S, Palma JM, Corpas FJ. Characterization of leucine aminopeptidase (LAP) activity in sweet pepper fruits during ripening and its inhibition by nitration and reducing events. PLANT CELL REPORTS 2024; 43:92. [PMID: 38466441 PMCID: PMC10927865 DOI: 10.1007/s00299-024-03179-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/22/2024] [Indexed: 03/13/2024]
Abstract
KEY MESSAGE Pepper fruits contain two leucine aminopeptidase (LAP) genes which are differentially modulated during ripening and by nitric oxide. The LAP activity increases during ripening but is negatively modulated by nitration. Leucine aminopeptidase (LAP) is an essential metalloenzyme that cleaves N-terminal leucine residues from proteins but also metabolizes dipeptides and tripeptides. LAPs play a fundamental role in cell protein turnover and participate in physiological processes such as defense mechanisms against biotic and abiotic stresses, but little is known about their involvement in fruit physiology. This study aims to identify and characterize genes encoding LAP and evaluate their role during the ripening of pepper (Capsicum annuum L.) fruits and under a nitric oxide (NO)-enriched environment. Using a data-mining approach of the pepper plant genome and fruit transcriptome (RNA-seq), two LAP genes, designated CaLAP1 and CaLAP2, were identified. The time course expression analysis of these genes during different fruit ripening stages showed that whereas CaLAP1 decreased, CaLAP2 was upregulated. However, under an exogenous NO treatment of fruits, both genes were downregulated. On the contrary, it was shown that during fruit ripening LAP activity increased by 81%. An in vitro assay of the LAP activity in the presence of different modulating compounds including peroxynitrite (ONOO-), NO donors (S-nitrosoglutathione and nitrosocyteine), reducing agents such as reduced glutathione (GSH), L-cysteine (L-Cys), and cyanide triggered a differential response. Thus, peroxynitrite and reducing compounds provoked around 50% inhibition of the LAP activity in green immature fruits, whereas cyanide upregulated it 1.5 folds. To our knowledge, this is the first characterization of LAP in pepper fruits as well as of its regulation by diverse modulating compounds. Based on the capacity of LAP to metabolize dipeptides and tripeptides, it could be hypothesized that the LAP might be involved in the GSH recycling during the ripening process.
Collapse
Affiliation(s)
- María A Muñoz-Vargas
- Department of Stress, Development and Signaling in Plants, Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Estación Experimental del Zaidín Spanish National Research Council, CSIC, C/Profesor Albareda, 1, 18008, Granada, Spain
| | - Jorge Taboada
- Department of Stress, Development and Signaling in Plants, Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Estación Experimental del Zaidín Spanish National Research Council, CSIC, C/Profesor Albareda, 1, 18008, Granada, Spain
| | - Salvador González-Gordo
- Department of Stress, Development and Signaling in Plants, Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Estación Experimental del Zaidín Spanish National Research Council, CSIC, C/Profesor Albareda, 1, 18008, Granada, Spain
| | - José M Palma
- Department of Stress, Development and Signaling in Plants, Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Estación Experimental del Zaidín Spanish National Research Council, CSIC, C/Profesor Albareda, 1, 18008, Granada, Spain
| | - Francisco J Corpas
- Department of Stress, Development and Signaling in Plants, Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Estación Experimental del Zaidín Spanish National Research Council, CSIC, C/Profesor Albareda, 1, 18008, Granada, Spain.
| |
Collapse
|
5
|
Geng R, Pang X, Li X, Shi S, Hedtke B, Grimm B, Bock R, Huang J, Zhou W. PROGRAMMED CELL DEATH8 interacts with tetrapyrrole biosynthesis enzymes and ClpC1 to maintain homeostasis of tetrapyrrole metabolites in Arabidopsis. THE NEW PHYTOLOGIST 2023; 238:2545-2560. [PMID: 36967598 DOI: 10.1111/nph.18906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 03/19/2023] [Indexed: 05/19/2023]
Abstract
Tetrapyrrole biosynthesis (TBS) is a dynamically and strictly regulated process. Disruptions in tetrapyrrole metabolism influence many aspects of plant physiology, including photosynthesis, programmed cell death (PCD), and retrograde signaling, thus affecting plant growth and development at multiple levels. However, the genetic and molecular basis of TBS is not fully understood. We report here PCD8, a newly identified thylakoid-localized protein encoded by an essential gene in Arabidopsis. PCD8 knockdown causes a necrotic phenotype due to excessive chloroplast damage. A burst of singlet oxygen that results from overaccumulated tetrapyrrole intermediates upon illumination is suggested to be responsible for cell death in the knockdown mutants. Genetic and biochemical analyses revealed that PCD8 interacts with ClpC1 and a number of TBS enzymes, such as HEMC, CHLD, and PORC of TBS. Taken together, our findings uncover the function of chloroplast-localized PCD8 and provide a new perspective to elucidate molecular mechanism of how TBS is finely regulated in plants.
Collapse
Affiliation(s)
- Rudan Geng
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xiaoqing Pang
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstraße 13, Berlin, 10115, Germany
| | - Xia Li
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Shanshan Shi
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Boris Hedtke
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstraße 13, Berlin, 10115, Germany
| | - Bernhard Grimm
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstraße 13, Berlin, 10115, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476, Potsdam-Golm, Germany
| | - Jirong Huang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Wenbin Zhou
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| |
Collapse
|
6
|
Di X, Ortega-Alarcon D, Kakumanu R, Iglesias-Fernandez J, Diaz L, Baidoo EEK, Velazquez-Campoy A, Rodríguez-Concepción M, Perez-Gil J. MEP pathway products allosterically promote monomerization of deoxy-D-xylulose-5-phosphate synthase to feedback-regulate their supply. PLANT COMMUNICATIONS 2023; 4:100512. [PMID: 36575800 DOI: 10.1016/j.xplc.2022.100512] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 12/11/2022] [Accepted: 12/22/2022] [Indexed: 05/11/2023]
Abstract
Isoprenoids are a very large and diverse family of metabolites required by all living organisms. All isoprenoids derive from the double-bond isomers isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), which are produced by the methylerythritol 4-phosphate (MEP) pathway in bacteria and plant plastids. It has been reported that IPP and DMAPP feedback-regulate the activity of deoxyxylulose 5-phosphate synthase (DXS), a dimeric enzyme that catalyzes the main flux-controlling step of the MEP pathway. Here we provide experimental insights into the underlying mechanism. Isothermal titration calorimetry and dynamic light scattering approaches showed that IPP and DMAPP can allosterically bind to DXS in vitro, causing a size shift. In silico ligand binding site analysis and docking calculations identified a potential allosteric site in the contact region between the two monomers of the active DXS dimer. Modulation of IPP and DMAPP contents in vivo followed by immunoblot analyses confirmed that high IPP/DMAPP levels resulted in monomerization and eventual aggregation of the enzyme in bacterial and plant cells. Loss of the enzymatically active dimeric conformation allows a fast and reversible reduction of DXS activity in response to a sudden increase or decrease in IPP/DMAPP supply, whereas aggregation and subsequent removal of monomers that would otherwise be available for dimerization appears to be a more drastic response in the case of persistent IPP/DMAPP overabundance (e.g., by a blockage in their conversion to downstream isoprenoids). Our results represent an important step toward understanding the regulation of the MEP pathway and rational design of biotechnological endeavors aimed at increasing isoprenoid contents in microbial and plant systems.
Collapse
Affiliation(s)
- Xueni Di
- Institute for Plant Molecular and Cell Biology (IBMCP), CSIC-Universitat Politècnica de València, 46022 Valencia, Spain; Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain
| | - David Ortega-Alarcon
- Institute for Biocomputation and Physics of Complex Systems (BIFI), Joint Unit GBsC-CSIC-BIFI, Universidad de Zaragoza, 50009 Zaragoza, Spain; Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Ramu Kakumanu
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA 94608, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | | | - Lucia Diaz
- Nostrum Biodiscovery SL, 08029 Barcelona, Spain
| | - Edward E K Baidoo
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA 94608, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Adrian Velazquez-Campoy
- Institute for Biocomputation and Physics of Complex Systems (BIFI), Joint Unit GBsC-CSIC-BIFI, Universidad de Zaragoza, 50009 Zaragoza, Spain; Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, 50009 Zaragoza, Spain; Instituto de Investigación Sanitaria de Aragón (IIS Aragon), 50009 Zaragoza, Spain; Centro de Investigación Biomédica en Red en el Área Temática de Enfermedades Hepáticas y Digestivas (CIBERehd), 28029 Madrid, Spain
| | - Manuel Rodríguez-Concepción
- Institute for Plant Molecular and Cell Biology (IBMCP), CSIC-Universitat Politècnica de València, 46022 Valencia, Spain; Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain.
| | - Jordi Perez-Gil
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain.
| |
Collapse
|
7
|
Winckler LI, Dissmeyer N. Molecular determinants of protein half-life in chloroplasts with focus on the Clp protease system. Biol Chem 2023; 404:499-511. [PMID: 36972025 DOI: 10.1515/hsz-2022-0320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/09/2023] [Indexed: 03/29/2023]
Abstract
Abstract
Proteolysis is an essential process to maintain cellular homeostasis. One pathway that mediates selective protein degradation and which is in principle conserved throughout the kingdoms of life is the N-degron pathway, formerly called the ‘N-end rule’. In the cytosol of eukaryotes and prokaryotes, N-terminal residues can be major determinants of protein stability. While the eukaryotic N-degron pathway depends on the ubiquitin proteasome system, the prokaryotic counterpart is driven by the Clp protease system. Plant chloroplasts also contain such a protease network, which suggests that they might harbor an organelle specific N-degron pathway similar to the prokaryotic one. Recent discoveries indicate that the N-terminal region of proteins affects their stability in chloroplasts and provides support for a Clp-mediated entry point in an N-degron pathway in plastids. This review discusses structure, function and specificity of the chloroplast Clp system, outlines experimental approaches to test for an N-degron pathway in chloroplasts, relates these aspects into general plastid proteostasis and highlights the importance of an understanding of plastid protein turnover.
Collapse
Affiliation(s)
- Lioba Inken Winckler
- Department of Plant Physiology and Protein Metabolism Laboratory, University of Osnabruck, Barbarastrasse 11, D-49076 Osnabruck, Germany
- Center of Cellular Nanoanalytics (CellNanOs), Barbarastrasse 11, D-49076 Osnabruck, Germany
- Faculty of Biology, University of Osnabruck, Barbarastrasse 11, D-49076 Osnabruck, Germany
| | - Nico Dissmeyer
- Department of Plant Physiology and Protein Metabolism Laboratory, University of Osnabruck, Barbarastrasse 11, D-49076 Osnabruck, Germany
- Center of Cellular Nanoanalytics (CellNanOs), Barbarastrasse 11, D-49076 Osnabruck, Germany
- Faculty of Biology, University of Osnabruck, Barbarastrasse 11, D-49076 Osnabruck, Germany
| |
Collapse
|
8
|
Sun Y, Li J, Zhang L, Lin R. Regulation of chloroplast protein degradation. J Genet Genomics 2023:S1673-8527(23)00049-8. [PMID: 36863685 DOI: 10.1016/j.jgg.2023.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/02/2023] [Accepted: 02/14/2023] [Indexed: 03/04/2023]
Abstract
Chloroplasts are unique organelles that not only provide sites for photosynthesis and many metabolic processes, but also are sensitive to various environmental stresses. Chloroplast proteins are encoded by genes from both nuclear and chloroplast genomes. During chloroplast development and responses to stresses, the robust protein quality control systems are essential for regulation of protein homeostasis and the integrity of chloroplast proteome. In this review, we summarize the regulatory mechanisms of chloroplast protein degradation refer to protease system, ubiquitin-proteasome system, and the chloroplast autophagy. These mechanisms symbiotically play a vital role in chloroplast development and photosynthesis under both normal or stress conditions.
Collapse
Affiliation(s)
- Yang Sun
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, Henan 475001, China
| | - Jialong Li
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Lixin Zhang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, Henan 475001, China.
| | - Rongcheng Lin
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
| |
Collapse
|
9
|
Moloi SJ, Ngara R. The roles of plant proteases and protease inhibitors in drought response: a review. FRONTIERS IN PLANT SCIENCE 2023; 14:1165845. [PMID: 37143877 PMCID: PMC10151539 DOI: 10.3389/fpls.2023.1165845] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 03/30/2023] [Indexed: 05/06/2023]
Abstract
Upon exposure to drought, plants undergo complex signal transduction events with concomitant changes in the expression of genes, proteins and metabolites. For example, proteomics studies continue to identify multitudes of drought-responsive proteins with diverse roles in drought adaptation. Among these are protein degradation processes that activate enzymes and signalling peptides, recycle nitrogen sources, and maintain protein turnover and homeostasis under stressful environments. Here, we review the differential expression and functional activities of plant protease and protease inhibitor proteins under drought stress, mainly focusing on comparative studies involving genotypes of contrasting drought phenotypes. We further explore studies of transgenic plants either overexpressing or repressing proteases or their inhibitors under drought conditions and discuss the potential roles of these transgenes in drought response. Overall, the review highlights the integral role of protein degradation during plant survival under water deficits, irrespective of the genotypes' level of drought resilience. However, drought-sensitive genotypes exhibit higher proteolytic activities, while drought-tolerant genotypes tend to protect proteins from degradation by expressing more protease inhibitors. In addition, transgenic plant biology studies implicate proteases and protease inhibitors in various other physiological functions under drought stress. These include the regulation of stomatal closure, maintenance of relative water content, phytohormonal signalling systems including abscisic acid (ABA) signalling, and the induction of ABA-related stress genes, all of which are essential for maintaining cellular homeostasis under water deficits. Therefore, more validation studies are required to explore the various functions of proteases and their inhibitors under water limitation and their contributions towards drought adaptation.
Collapse
|
10
|
Rowland E, Kim J, Friso G, Poliakov A, Ponnala L, Sun Q, van Wijk KJ. The CLP and PREP protease systems coordinate maturation and degradation of the chloroplast proteome in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2022; 236:1339-1357. [PMID: 35946374 DOI: 10.1111/nph.18426] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
A network of peptidases governs proteostasis in plant chloroplasts and mitochondria. This study reveals strong genetic and functional interactions in Arabidopsis between the chloroplast stromal CLP chaperone-protease system and the PREP1,2 peptidases, which are dually localized to chloroplast stroma and the mitochondrial matrix. Higher order mutants defective in CLP or PREP proteins were generated and analyzed by quantitative proteomics and N-terminal proteomics (terminal amine isotopic labeling of substrates (TAILS)). Strong synergistic interactions were observed between the CLP protease system (clpr1-2, clpr2-1, clpc1-1, clpt1, clpt2) and both PREP homologs (prep1, prep2) resulting in embryo lethality or growth and developmental phenotypes. Synergistic interactions were observed even when only one of the PREP proteins was lacking, suggesting that PREP1 and PREP2 have divergent substrates. Proteome phenotypes were driven by the loss of CLP protease capacity, with little impact from the PREP peptidases. Chloroplast N-terminal proteomes showed that many nuclear encoded chloroplast proteins have alternatively processed N-termini in prep1prep2, clpt1clpt2 and prep1prep2clpt1clpt2. Loss of chloroplast protease capacity interferes with stromal processing peptidase (SPP) activity due to folding stress and low levels of accumulated cleaved cTP fragments. PREP1,2 proteolysis of cleaved cTPs is complemented by unknown proteases. A model for CLP and PREP activity within a hierarchical chloroplast proteolysis network is proposed.
Collapse
Affiliation(s)
- Elden Rowland
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, NY, 14853, USA
| | - Jitae Kim
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, NY, 14853, USA
- S-Korea Bioenergy Research Center, Chonnam National University, Gwangju, 61186, South Korea
| | - Giulia Friso
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, NY, 14853, USA
| | - Anton Poliakov
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, NY, 14853, USA
| | | | - Qi Sun
- Computational Biology Service Unit, Cornell University, Ithaca, NY, 14853, USA
| | - Klaas J van Wijk
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, NY, 14853, USA
| |
Collapse
|
11
|
Chloroplast envelope ATPase PGA1/AtFtsH12 is required for chloroplast protein accumulation and cytosol-chloroplast protein homeostasis in Arabidopsis. J Biol Chem 2022; 298:102489. [PMID: 36113581 PMCID: PMC9574505 DOI: 10.1016/j.jbc.2022.102489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 11/20/2022] Open
Abstract
The establishment of photosynthetic protein complexes during chloroplast development requires the influx of a large number of chloroplast proteins that are encoded by the nuclear genome, which is critical for cytosol and chloroplast protein homeostasis and chloroplast development. However, the mechanisms regulating this process are still not well understood in higher plants. Here, we report the isolation and characterization of the pale green Arabidopsis pga1-1 mutant, which is defective in chloroplast development and chloroplast protein accumulation. Using genetic and biochemical evidence, we reveal that PGA1 encodes AtFtsH12, a chloroplast envelope-localized protein of the FtsH family proteins. We determined a G703R mutation in the GAD motif of the conserved ATPase domain renders the pga1-1 a viable hypomorphic allele of the essential gene AtFtsH12. In de-etiolation assays, we showed that the accumulation of photosynthetic proteins and the expression of photosynthetic genes were impaired in pga1-1. Using the FNRctp-GFP and pTAC2-GFP reporters, we demonstrated that AtFtsH12 was required for the accumulation of chloroplast proteins in vivo. Interestingly, we identified an increase in expression of the mutant AtFtsH12 gene in pga1-1, suggesting a feedback regulation. Moreover, we found that cytosolic and chloroplast proteostasis responses were triggered in pga1-1. Together, taking advantage of the novel pga1-1 mutant, we demonstrate the function of AtFtsH12 in chloroplast protein homeostasis and chloroplast development.
Collapse
|
12
|
A proteostasis network safeguards the chloroplast proteome. Essays Biochem 2022; 66:219-228. [PMID: 35670042 PMCID: PMC9400067 DOI: 10.1042/ebc20210058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/17/2022] [Accepted: 05/25/2022] [Indexed: 12/12/2022]
Abstract
Several protein homeostasis (proteostasis) pathways safeguard the integrity of thousands of proteins that localize in plant chloroplasts, the indispensable organelles that perform photosynthesis, produce metabolites, and sense environmental stimuli. In this review, we discuss the latest efforts directed to define the molecular process by which proteins are imported and sorted into the chloroplast. Moreover, we describe the recently elucidated protein folding and degradation pathways that modulate the levels and activities of chloroplast proteins. We also discuss the links between the accumulation of misfolded proteins and the activation of signalling pathways that cope with folding stress within the organelle. Finally, we propose new research directions that would help to elucidate novel molecular mechanisms to maintain chloroplast proteostasis.
Collapse
|
13
|
Luo X, Zhang M, Xu P, Liu G, Wei S. The Intron Retention Variant CsClpP3m Is Involved in Leaf Chlorosis in Some Tea Cultivars. FRONTIERS IN PLANT SCIENCE 2022; 12:804428. [PMID: 35154195 PMCID: PMC8831552 DOI: 10.3389/fpls.2021.804428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
Tea products made from chlorotic or albino leaves are very popular for their unique flavor. Probing into the molecular mechanisms underlying the chlorotic leaf phenotype is required to better understand the formation of these tea cultivars and aid in future practical breeding. In this study, transcriptional alterations of multiple subunit genes of the caseinolytic protease complex (Clp) in the chlorotic tea cultivar 'Yu-Jin-Xiang' (YJX) were found. Cultivar YJX possessed the intron retention variant of ClpP3, named as CsClpP3m, in addition to the non-mutated ClpP3. The mutated variant results in a truncated protein containing only 166 amino acid residues and lacks the catalytic triad S182-H206-D255. Quantitative analysis of two CsClpP3 variants in different leaves with varying degrees of chlorosis in YJX and analyses of different chlorotic tea cultivars revealed that the transcript ratios of CsClpP3m over CsClpP3 were negatively correlated with leaf chlorophyll contents. The chlorotic young leaf phenotype was also generated in the transgenic tobacco by suppressing ClpP3 using the RNAi method; complementation with non-mutated CsClpP3 rescued the wild-type phenotype, whereas CsClpP3m failed to complement. Taken together, CsClpP3m is involved in leaf chlorosis in YJX and some other tea cultivars in a dose-dependent manner, likely resulting from the failure of Clp complex assembly due to the truncated sequence of CsClpP3m. Our data shed light on the mechanisms controlling leaf chlorosis in tea plants.
Collapse
Affiliation(s)
- Xueyin Luo
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Mengxian Zhang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Pei Xu
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| | - Guofeng Liu
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
- Henan Provincial Key Laboratory of Tea Plant Biology, Xinyang Normal University, Xinyang, China
| | - Shu Wei
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
| |
Collapse
|
14
|
Gámez-Arcas S, Baroja-Fernández E, García-Gómez P, Muñoz FJ, Almagro G, Bahaji A, Sánchez-López ÁM, Pozueta-Romero J. Action mechanisms of small microbial volatile compounds in plants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:498-510. [PMID: 34687197 DOI: 10.1093/jxb/erab463] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 10/21/2021] [Indexed: 05/22/2023]
Abstract
Microorganisms communicate with plants by exchanging chemical signals throughout the phytosphere. Before direct contact with plants occurs, beneficial microorganisms emit a plethora of volatile compounds that promote plant growth and photosynthesis as well as developmental, metabolic, transcriptional, and proteomic changes in plants. These compounds can also induce systemic drought tolerance and improve water and nutrient acquisition. Recent studies have shown that this capacity is not restricted to beneficial microbes; it also extends to phytopathogens. Plant responses to microbial volatile compounds have frequently been associated with volatile organic compounds with molecular masses ranging between ~ 45Da and 300Da. However, microorganisms also release a limited number of volatile compounds with molecular masses of less than ~45Da that react with proteins and/or act as signaling molecules. Some of these compounds promote photosynthesis and growth when exogenously applied in low concentrations. Recently, evidence has shown that small volatile compounds are important determinants of plant responses to microbial volatile emissions. However, the regulatory mechanisms involved in these responses remain poorly understood. This review summarizes current knowledge of biochemical and molecular mechanisms involved in plant growth, development, and metabolic responses to small microbial volatile compounds.
Collapse
Affiliation(s)
- Samuel Gámez-Arcas
- Instituto de Agrobiotecnología (CSIC/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Edurne Baroja-Fernández
- Instituto de Agrobiotecnología (CSIC/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Pablo García-Gómez
- Plant Nutrition Department, Centro de Edafología y Biología Aplicada (CEBAS-CSIC), Campus Universitario de Espinardo, Espinardo, 30100 Murcia, Spain
| | - Francisco José Muñoz
- Instituto de Agrobiotecnología (CSIC/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Goizeder Almagro
- Instituto de Agrobiotecnología (CSIC/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Abdellatif Bahaji
- Instituto de Agrobiotecnología (CSIC/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Ángela María Sánchez-López
- Instituto de Agrobiotecnología (CSIC/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Javier Pozueta-Romero
- Institute for Mediterranean and Subtropical Horticulture 'La Mayora' (IHSM-UMA-CSIC), Campus de Teatinos, Avda. Louis Pasteur, 49, 29010 Málaga, Spain
| |
Collapse
|
15
|
Rei Liao JY, Friso G, Forsythe ES, Michel EJS, Williams AM, Boguraev SS, Ponnala L, Sloan DB, van Wijk KJ. Proteomics, phylogenetics, and co-expression analyses indicate novel interactions in the plastid CLP chaperone-protease system. J Biol Chem 2022; 298:101609. [PMID: 35065075 PMCID: PMC8889267 DOI: 10.1016/j.jbc.2022.101609] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 01/13/2022] [Accepted: 01/16/2022] [Indexed: 12/20/2022] Open
Abstract
The chloroplast chaperone CLPC1 unfolds and delivers substrates to the stromal CLPPRT protease complex for degradation. We previously used an in vivo trapping approach to identify interactors with CLPC1 in Arabidopsis thaliana by expressing a STREPII-tagged copy of CLPC1 mutated in its Walker B domains (CLPC1-TRAP) followed by affinity purification and mass spectrometry. To create a larger pool of candidate substrates, adaptors, or regulators, we carried out a far more sensitive and comprehensive in vivo protein trapping analysis. We identified 59 highly enriched CLPC1 protein interactors, in particular proteins belonging to families of unknown functions (DUF760, DUF179, DUF3143, UVR-DUF151, HugZ/DUF2470), as well as the UVR domain proteins EXE1 and EXE2 implicated in singlet oxygen damage and signaling. Phylogenetic and functional domain analyses identified other members of these families that appear to localize (nearly) exclusively to plastids. In addition, several of these DUF proteins are of very low abundance as determined through the Arabidopsis PeptideAtlas http://www.peptideatlas.org/builds/arabidopsis/ showing that enrichment in the CLPC1-TRAP was extremely selective. Evolutionary rate covariation indicated that the HugZ/DUF2470 family coevolved with the plastid CLP machinery suggesting functional and/or physical interactions. Finally, mRNA-based coexpression networks showed that all 12 CLP protease subunits tightly coexpressed as a single cluster with deep connections to DUF760-3. Coexpression modules for other trapped proteins suggested specific functions in biological processes, e.g., UVR2 and UVR3 were associated with extraplastidic degradation, whereas DUF760-6 is likely involved in senescence. This study provides a strong foundation for discovery of substrate selection by the chloroplast CLP protease system.
Collapse
Affiliation(s)
- Jui-Yun Rei Liao
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York, USA
| | - Giulia Friso
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York, USA
| | - Evan S Forsythe
- Graduate Program in Cell and Molecular Biology, Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Elena J S Michel
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York, USA
| | - Alissa M Williams
- Graduate Program in Cell and Molecular Biology, Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Sasha S Boguraev
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York, USA
| | | | - Daniel B Sloan
- Graduate Program in Cell and Molecular Biology, Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Klaas J van Wijk
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York, USA.
| |
Collapse
|
16
|
Birdseye D, de Boer LA, Bai H, Zhou P, Shen Z, Schmelz EA, Springer NM, Briggs SP. Plant height heterosis is quantitatively associated with expression levels of plastid ribosomal proteins. Proc Natl Acad Sci U S A 2021; 118:e2109332118. [PMID: 34782463 PMCID: PMC8617506 DOI: 10.1073/pnas.2109332118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2021] [Indexed: 11/25/2022] Open
Abstract
The use of hybrids is widespread in agriculture, yet the molecular basis for hybrid vigor (heterosis) remains obscure. To identify molecular components that may contribute to trait heterosis, we analyzed paired proteomic and transcriptomic data from seedling leaf and mature leaf blade tissues of maize hybrids and their inbred parents. Nuclear- and plastid-encoded subunits of complexes required for protein synthesis in the chloroplast and for the light reactions of photosynthesis were expressed above midparent and high-parent levels, respectively. Consistent with previous reports in Arabidopsis, ethylene biosynthetic enzymes were expressed below midparent levels in the hybrids, suggesting a conserved mechanism for heterosis between monocots and dicots. The ethylene biosynthesis mutant, acs2/acs6, largely phenocopied the hybrid proteome, indicating that a reduction in ethylene biosynthesis may mediate the differences between inbreds and their hybrids. To rank the relevance of expression differences to trait heterosis, we compared seedling leaf protein levels to the adult plant height of 15 hybrids. Hybrid/midparent expression ratios were most positively correlated with hybrid/midparent plant height ratios for the chloroplast ribosomal proteins. Our results show that increased expression of chloroplast ribosomal proteins in hybrid seedling leaves is mediated by reduced expression of ethylene biosynthetic enzymes and that the degree of their overexpression in seedlings can quantitatively predict adult trait heterosis.
Collapse
Affiliation(s)
- Devon Birdseye
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093
| | - Laura A de Boer
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093
| | - Hua Bai
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093
| | - Peng Zhou
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108
| | - Zhouxin Shen
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093
| | - Eric A Schmelz
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093
| | - Nathan M Springer
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108
| | - Steven P Briggs
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093;
| |
Collapse
|
17
|
Arabidopsis PII Proteins Form Characteristic Foci in Chloroplasts Indicating Novel Properties in Protein Interaction and Degradation. Int J Mol Sci 2021; 22:ijms222312666. [PMID: 34884470 PMCID: PMC8657445 DOI: 10.3390/ijms222312666] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 11/16/2021] [Accepted: 11/21/2021] [Indexed: 11/16/2022] Open
Abstract
The PII protein is an evolutionary, highly conserved regulatory protein found in both bacteria and higher plants. In bacteria, it modulates the activity of several enzymes, transporters, and regulatory factors by interacting with them and thereby regulating important metabolic hubs, such as carbon/nitrogen homeostasis. More than two decades ago, the PII protein was characterized for the first time in plants, but its physiological role is still not sufficiently resolved. To gain more insights into the function of this protein, we investigated the interaction behavior of AtPII with candidate proteins by BiFC and FRET/FLIM in planta and with GFP/RFP traps in vitro. In the course of these studies, we found that AtPII interacts in chloroplasts with itself as well as with known interactors such as N-acetyl-L-glutamate kinase (NAGK) in dot-like aggregates, which we named PII foci. In these novel protein aggregates, AtPII also interacts with yet unknown partners, which are known to be involved in plastidic protein degradation. Further studies revealed that the C-terminal component of AtPII is crucial for the formation of PII foci. Altogether, the discovery and description of PII foci indicate a novel mode of interaction between PII proteins and other proteins in plants. These findings may represent a new starting point for the elucidation of physiological functions of PII proteins in plants.
Collapse
|
18
|
Torres-Montilla S, Rodriguez-Concepcion M. Making extra room for carotenoids in plant cells: New opportunities for biofortification. Prog Lipid Res 2021; 84:101128. [PMID: 34530006 DOI: 10.1016/j.plipres.2021.101128] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 09/06/2021] [Accepted: 09/09/2021] [Indexed: 12/22/2022]
Abstract
Plant carotenoids are essential for photosynthesis and photoprotection and provide colors in the yellow to red range to non-photosynthetic organs such as petals and ripe fruits. They are also the precursors of biologically active molecules not only in plants (including hormones and retrograde signals) but also in animals (including retinoids such as vitamin A). A carotenoid-rich diet has been associated with improved health and cognitive capacity in humans, whereas the use of carotenoids as natural pigments is widespread in the agrofood and cosmetic industries. The nutritional and economic relevance of carotenoids has spurred a large number of biotechnological strategies to enrich plant tissues with carotenoids. Most of such approaches to alter carotenoid contents in plants have been focused on manipulating their biosynthesis or degradation, whereas improving carotenoid sink capacity in plant tissues has received much less attention. Our knowledge on the molecular mechanisms influencing carotenoid storage in plants has substantially grown in the last years, opening new opportunities for carotenoid biofortification. Here we will review these advances with a particular focus on those creating extra room for carotenoids in plant cells either by promoting the differentiation of carotenoid-sequestering structures within plastids or by transferring carotenoid production to the cytosol.
Collapse
Affiliation(s)
- Salvador Torres-Montilla
- Institute for Plant Molecular and Cell Biology (IBMCP), Agencia Estatal Consejo Superior de Investigaciones Cientificas - Universitat Politècnica de València, 46022 Valencia, Spain
| | - Manuel Rodriguez-Concepcion
- Institute for Plant Molecular and Cell Biology (IBMCP), Agencia Estatal Consejo Superior de Investigaciones Cientificas - Universitat Politècnica de València, 46022 Valencia, Spain.
| |
Collapse
|
19
|
Li M, Guo G, Pidon H, Melzer M, Prina AR, Börner T, Stein N. ATP-Dependent Clp Protease Subunit C1, HvClpC1, Is a Strong Candidate Gene for Barley Variegation Mutant luteostrians as Revealed by Genetic Mapping and Genomic Re-sequencing. FRONTIERS IN PLANT SCIENCE 2021; 12:664085. [PMID: 33936155 PMCID: PMC8086601 DOI: 10.3389/fpls.2021.664085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
Implementation of next-generation sequencing in forward genetic screens greatly accelerated gene discovery in species with larger genomes, including many crop plants. In barley, extensive mutant collections are available, however, the causative mutations for many of the genes remains largely unknown. Here we demonstrate how a combination of low-resolution genetic mapping, whole-genome resequencing and comparative functional analyses provides a promising path toward candidate identification of genes involved in plastid biology and/or photosynthesis, even if genes are located in recombination poor regions of the genome. As a proof of concept, we simulated the prediction of a candidate gene for the recently cloned variegation mutant albostrians (HvAST/HvCMF7) and adopted the approach for suggesting HvClpC1 as candidate gene for the yellow-green variegation mutant luteostrians.
Collapse
Affiliation(s)
- Mingjiu Li
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Ganggang Guo
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hélène Pidon
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Michael Melzer
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Alberto R. Prina
- Institute of Genetics ‘Ewald A. Favret’ (IGEAF), INTA CICVyA/Argentina, Hurlingham, Buenos Aires, Argentina
| | - Thomas Börner
- Molecular Genetics, Institute of Biology, Humboldt University, Berlin, Germany
| | - Nils Stein
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
- Center for Integrated Breeding Research (CiBreed), Department of Crop Sciences, Georg-August-University, Göttingen, Germany
| |
Collapse
|
20
|
Rödiger A, Agne B, Dobritzsch D, Helm S, Müller F, Pötzsch N, Baginsky S. Chromoplast differentiation in bell pepper (Capsicum annuum) fruits. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:1431-1442. [PMID: 33258209 DOI: 10.1111/tpj.15104] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/20/2020] [Accepted: 11/24/2020] [Indexed: 05/21/2023]
Abstract
We report here a detailed analysis of the proteome adjustments that accompany chromoplast differentiation from chloroplasts during bell pepper (Capsicum annuum) fruit ripening. While the two photosystems are disassembled and their constituents degraded, the cytochrome b6 f complex, the ATPase complex, and Calvin cycle enzymes are maintained at high levels up to fully mature chromoplasts. This is also true for ferredoxin (Fd) and Fd-dependent NADP reductase, suggesting that ferredoxin retains a central role in the chromoplasts' redox metabolism. There is a significant increase in the amount of enzymes of the typical metabolism of heterotrophic plastids, such as the oxidative pentose phosphate pathway (OPPP) and amino acid and fatty acid biosynthesis. Enzymes of chlorophyll catabolism and carotenoid biosynthesis increase in abundance, supporting the pigment reorganization that goes together with chromoplast differentiation. The majority of plastid encoded proteins decline but constituents of the plastid ribosome and AccD increase in abundance. Furthermore, the amount of plastid terminal oxidase (PTOX) remains unchanged despite a significant increase in phytoene desaturase (PDS) levels, suggesting that the electrons from phytoene desaturation are consumed by another oxidase. This may be a particularity of non-climacteric fruits such as bell pepper that lack a respiratory burst at the onset of fruit ripening.
Collapse
Affiliation(s)
- Anja Rödiger
- Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
- Biochemistry of Plants, Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | - Birgit Agne
- Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
- Biochemistry of Plants, Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | - Dirk Dobritzsch
- Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
| | - Stefan Helm
- Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
| | - Fränze Müller
- Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
- Biochemistry and Functional Proteomics, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | - Nina Pötzsch
- Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
| | - Sacha Baginsky
- Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
- Biochemistry of Plants, Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
| |
Collapse
|
21
|
Bouchnak I, van Wijk KJ. Structure, function, and substrates of Clp AAA+ protease systems in cyanobacteria, plastids, and apicoplasts: A comparative analysis. J Biol Chem 2021; 296:100338. [PMID: 33497624 PMCID: PMC7966870 DOI: 10.1016/j.jbc.2021.100338] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/22/2021] [Accepted: 01/22/2021] [Indexed: 02/08/2023] Open
Abstract
ATPases Associated with diverse cellular Activities (AAA+) are a superfamily of proteins that typically assemble into hexameric rings. These proteins contain AAA+ domains with two canonical motifs (Walker A and B) that bind and hydrolyze ATP, allowing them to perform a wide variety of different functions. For example, AAA+ proteins play a prominent role in cellular proteostasis by controlling biogenesis, folding, trafficking, and degradation of proteins present within the cell. Several central proteolytic systems (e.g., Clp, Deg, FtsH, Lon, 26S proteasome) use AAA+ domains or AAA+ proteins to unfold protein substrates (using energy from ATP hydrolysis) to make them accessible for degradation. This allows AAA+ protease systems to degrade aggregates and large proteins, as well as smaller proteins, and feed them as linearized molecules into a protease chamber. This review provides an up-to-date and a comparative overview of the essential Clp AAA+ protease systems in Cyanobacteria (e.g., Synechocystis spp), plastids of photosynthetic eukaryotes (e.g., Arabidopsis, Chlamydomonas), and apicoplasts in the nonphotosynthetic apicomplexan pathogen Plasmodium falciparum. Recent progress and breakthroughs in identifying Clp protease structures, substrates, substrate adaptors (e.g., NblA/B, ClpS, ClpF), and degrons are highlighted. We comment on the physiological importance of Clp activity, including plastid biogenesis, proteostasis, the chloroplast Protein Unfolding Response, and metabolism, across these diverse lineages. Outstanding questions as well as research opportunities and priorities to better understand the essential role of Clp systems in cellular proteostasis are discussed.
Collapse
Affiliation(s)
- Imen Bouchnak
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York, USA
| | - Klaas J van Wijk
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York, USA.
| |
Collapse
|
22
|
Ameztoy K, Sánchez-López ÁM, Muñoz FJ, Bahaji A, Almagro G, Baroja-Fernández E, Gámez-Arcas S, De Diego N, Doležal K, Novák O, Pěnčík A, Alpízar A, Rodríguez-Concepción M, Pozueta-Romero J. Proteostatic Regulation of MEP and Shikimate Pathways by Redox-Activated Photosynthesis Signaling in Plants Exposed to Small Fungal Volatiles. FRONTIERS IN PLANT SCIENCE 2021; 12:637976. [PMID: 33747018 PMCID: PMC7973468 DOI: 10.3389/fpls.2021.637976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/28/2021] [Indexed: 05/07/2023]
Abstract
Microorganisms produce volatile compounds (VCs) with molecular masses of less than 300 Da that promote plant growth and photosynthesis. Recently, we have shown that small VCs of less than 45 Da other than CO2 are major determinants of plant responses to fungal volatile emissions. However, the regulatory mechanisms involved in the plants' responses to small microbial VCs remain unclear. In Arabidopsis thaliana plants exposed to small fungal VCs, growth promotion is accompanied by reduction of the thiol redox of Calvin-Benson cycle (CBC) enzymes and changes in the levels of shikimate and 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway-related compounds. We hypothesized that plants' responses to small microbial VCs involve post-translational modulation of enzymes of the MEP and shikimate pathways via mechanisms involving redox-activated photosynthesis signaling. To test this hypothesis, we compared the responses of wild-type (WT) plants and a cfbp1 mutant defective in a redox-regulated isoform of the CBC enzyme fructose-1,6-bisphosphatase to small VCs emitted by the fungal phytopathogen Alternaria alternata. Fungal VC-promoted growth and photosynthesis, as well as metabolic and proteomic changes, were substantially weaker in cfbp1 plants than in WT plants. In WT plants, but not in cfbp1 plants, small fungal VCs reduced the levels of both transcripts and proteins of the stromal Clp protease system and enhanced those of plastidial chaperonins and co-chaperonins. Consistently, small fungal VCs promoted the accumulation of putative Clp protease clients including MEP and shikimate pathway enzymes. clpr1-2 and clpc1 mutants with disrupted plastidial protein homeostasis responded weakly to small fungal VCs, strongly indicating that plant responses to microbial volatile emissions require a finely regulated plastidial protein quality control system. Our findings provide strong evidence that plant responses to fungal VCs involve chloroplast-to-nucleus retrograde signaling of redox-activated photosynthesis leading to proteostatic regulation of the MEP and shikimate pathways.
Collapse
Affiliation(s)
- Kinia Ameztoy
- Instituto de Agrobiotecnología (Consejo Superior de Investigaciones Científicas/Gobierno de Navarra), Mutilva, Spain
| | - Ángela María Sánchez-López
- Instituto de Agrobiotecnología (Consejo Superior de Investigaciones Científicas/Gobierno de Navarra), Mutilva, Spain
| | - Francisco José Muñoz
- Instituto de Agrobiotecnología (Consejo Superior de Investigaciones Científicas/Gobierno de Navarra), Mutilva, Spain
| | - Abdellatif Bahaji
- Instituto de Agrobiotecnología (Consejo Superior de Investigaciones Científicas/Gobierno de Navarra), Mutilva, Spain
| | - Goizeder Almagro
- Instituto de Agrobiotecnología (Consejo Superior de Investigaciones Científicas/Gobierno de Navarra), Mutilva, Spain
| | - Edurne Baroja-Fernández
- Instituto de Agrobiotecnología (Consejo Superior de Investigaciones Científicas/Gobierno de Navarra), Mutilva, Spain
| | - Samuel Gámez-Arcas
- Instituto de Agrobiotecnología (Consejo Superior de Investigaciones Científicas/Gobierno de Navarra), Mutilva, Spain
| | - Nuria De Diego
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Karel Doležal
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czechia
- Laboratory of Growth Regulators, Faculty of Science of Palackı University and Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, Czechia
| | - Ondřej Novák
- Laboratory of Growth Regulators, Faculty of Science of Palackı University and Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, Czechia
| | - Ales Pěnčík
- Laboratory of Growth Regulators, Faculty of Science of Palackı University and Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, Czechia
| | - Adán Alpízar
- Unidad de Proteómica Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | | | - Javier Pozueta-Romero
- Instituto de Agrobiotecnología (Consejo Superior de Investigaciones Científicas/Gobierno de Navarra), Mutilva, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC) Campus de Teatinos, Málaga, Spain
- *Correspondence: Javier Pozueta-Romero,
| |
Collapse
|
23
|
Plastid biogenesis in malaria parasites requires the interactions and catalytic activity of the Clp proteolytic system. Proc Natl Acad Sci U S A 2020; 117:13719-13729. [PMID: 32482878 DOI: 10.1073/pnas.1919501117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The human malaria parasite, Plasmodium falciparum, contains an essential plastid called the apicoplast. Most apicoplast proteins are encoded by the nuclear genome and it is unclear how the plastid proteome is regulated. Here, we study an apicoplast-localized caseinolytic-protease (Clp) system and how it regulates organelle proteostasis. Using null and conditional mutants, we demonstrate that the P. falciparum Clp protease (PfClpP) has robust enzymatic activity that is essential for apicoplast biogenesis. We developed a CRISPR/Cas9-based system to express catalytically dead PfClpP, which showed that PfClpP oligomerizes as a zymogen and is matured via transautocatalysis. The expression of both wild-type and mutant Clp chaperone (PfClpC) variants revealed a functional chaperone-protease interaction. Conditional mutants of the substrate-adaptor (PfClpS) demonstrated its essential function in plastid biogenesis. A combination of multiple affinity purification screens identified the Clp complex composition as well as putative Clp substrates. This comprehensive study reveals the molecular composition and interactions influencing the proteolytic function of the apicoplast Clp system and demonstrates its central role in the biogenesis of the plastid in malaria parasites.
Collapse
|
24
|
Ali MS, Baek KH. Co-suppression of NbClpC1 and NbClpC2 alters plant morphology with changed hormone levels in Nicotiana benthamiana. PLANT CELL REPORTS 2019; 38:1317-1328. [PMID: 31385037 DOI: 10.1007/s00299-019-02452-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 07/23/2019] [Indexed: 06/10/2023]
Abstract
KEY MESSAGE Co-suppression of chaperonic ClpC1 and ClpC2 in Nicotiana benthamiana significantly affect the development and exogenous application of gibberellin partially rescue the developmental defects. Over the past decade, the Clp protease complex has been identified as being implicated in plastid protein quality control in plant cells. CLPC1 and CLPC2 proteins form the chaperone subunits of the Clp protease complex and unfold protein substrates to thread them into the ClpP complex. Here, using the technique of virus-induced gene silencing (VIGS), we suppressed both Nicotiana benthamiana ClpC1 and ClpC2 (NbClpC1/C2) functioning as chaperone subunits in the protease complex. Co-suppression of NbClpC1/C2 caused chlorosis and retarded-growth phenotype with no seed formation and significantly reduced root length. We found that co-suppression of NbClpC1/C2 also affected stomata and trichome formation and vascular bundle differentiation and patterning. Analysis of phytohormones revealed significant alteration and imbalance of major hormones in the leaves of NbClpC1/C2 co-suppressed plant. We also found that application of gibberellin (GA3) partially rescued the developmental defects. Co-suppression of NbClpC1/C2 significantly affected the development of N. benthamiana and exogenous application of GA3 partially rescued the developmental defects. Overall, our findings demonstrate that CLPC1 and CLPC2 proteins have a pivotal role in plant growth and development.
Collapse
Affiliation(s)
- Md Sarafat Ali
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea
| | - Kwang-Hyun Baek
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea.
| |
Collapse
|
25
|
Montandon C, Friso G, Liao JYR, Choi J, van Wijk KJ. In Vivo Trapping of Proteins Interacting with the Chloroplast CLPC1 Chaperone: Potential Substrates and Adaptors. J Proteome Res 2019; 18:2585-2600. [DOI: 10.1021/acs.jproteome.9b00112] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Cyrille Montandon
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York 14853, United States
| | - Giulia Friso
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York 14853, United States
| | - Jui-Yun Rei Liao
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York 14853, United States
| | - Junsik Choi
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York 14853, United States
| | - Klaas J. van Wijk
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, New York 14853, United States
| |
Collapse
|
26
|
Stael S, Van Breusegem F, Gevaert K, Nowack MK. Plant proteases and programmed cell death. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1991-1995. [PMID: 31222306 PMCID: PMC6460956 DOI: 10.1093/jxb/erz126] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- Simon Stael
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB-UGent Center for Plant Systems Biology, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- VIB-UGent Center for Medical Biotechnology, Ghent, Belgium
| | - Frank Van Breusegem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB-UGent Center for Plant Systems Biology, Ghent, Belgium
| | - Kris Gevaert
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- VIB-UGent Center for Medical Biotechnology, Ghent, Belgium
| | - Moritz K Nowack
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB-UGent Center for Plant Systems Biology, Ghent, Belgium
| |
Collapse
|
27
|
D’Andrea L, Rodriguez-Concepcion M. Manipulation of Plastidial Protein Quality Control Components as a New Strategy to Improve Carotenoid Contents in Tomato Fruit. FRONTIERS IN PLANT SCIENCE 2019; 10:1071. [PMID: 31543891 PMCID: PMC6739439 DOI: 10.3389/fpls.2019.01071] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 08/07/2019] [Indexed: 05/19/2023]
Abstract
Carotenoids such as β-carotene (pro-vitamin A) and lycopene accumulate at high levels during tomato (Solanum lycopersicum L.) fruit ripening, contributing to the characteristic color and nutritional quality of ripe tomatoes. Besides their role as pigments in chromoplast-harboring tissues such as ripe fruits, carotenoids are important for photosynthesis and photoprotection in the chloroplasts of photosynthetic tissues. Interestingly, recent work in Arabidopsis thaliana (L.) Heynh. has unveiled a critical role of chloroplast protein quality control components in the regulation of carotenoid biosynthesis. The accumulation (i.e. degradation rate) and activity (i.e. folding status) of phytoene synthase (PSY) and other Arabidopsis biosynthetic enzymes is modulated by chaperones such as Orange (OR) and Hsp70 in coordination with the stromal Clp protease complex. OR and Clp protease were recently shown to also influence PSY stability and carotenoid accumulation in tomato. Here we show how manipulating the levels of plastid-localized Hsp70 in transgenic tomato plants can also impact the accumulation of carotenoids in ripe fruit. The resulting carotenoid profile and chromoplast ultrastructure, however, are different from those obtained in tomatoes from transgenic lines with increased OR activity. These results suggest that different chaperone families target different processes related to carotenoid metabolism and accumulation during tomato ripening. We further discuss other possible targets for future manipulation in tomato based on the knowledge acquired in Arabidopsis.
Collapse
Affiliation(s)
- Lucio D’Andrea
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Manuel Rodriguez-Concepcion
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Barcelona, Spain
- Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
- *Correspondence: Manuel Rodriguez-Concepcion,
| |
Collapse
|
28
|
Feder A, Chayut N, Gur A, Freiman Z, Tzuri G, Meir A, Saar U, Ohali S, Baumkoler F, Gal-On A, Shnaider Y, Wolf D, Katzir N, Schaffer A, Burger J, Li L, Tadmor Y. The Role of Carotenogenic Metabolic Flux in Carotenoid Accumulation and Chromoplast Differentiation: Lessons From the Melon Fruit. FRONTIERS IN PLANT SCIENCE 2019; 10:1250. [PMID: 31736986 PMCID: PMC6833967 DOI: 10.3389/fpls.2019.01250] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 09/09/2019] [Indexed: 05/19/2023]
Abstract
Carotenoids have various roles in plant physiology. Plant carotenoids are synthesized in plastids and are highly abundant in the chromoplasts of ripening fleshy fruits. Considerable research efforts have been devoted to elucidating mechanisms that regulate carotenoid biosynthesis, yet, little is known about the mechanism that triggers storage capacity, mainly through chromoplast differentiation. The Orange gene (OR) product stabilizes phytoene synthase protein (PSY) and triggers chromoplast differentiation. OR underlies carotenoid accumulation in orange cauliflower and melon. The OR's 'golden SNP', found in melon, alters the highly evolutionary conserved Arginine108 to Histidine and controls β-carotene accumulation in melon fruit, in a mechanism yet to be elucidated. We have recently shown that similar carotenogenic metabolic flux is active in non-orange and orange melon fruit. This flux probably leads to carotenoid turnover but known carotenoid turnover products are not detected in non-orange fruit. Arrest of this metabolic flux, using chemical inhibitors or mutations, induces carotenoid accumulation and biogenesis of chromoplasts, regardless of the allelic state of OR. We suggest that the 'golden SNP' induces β-carotene accumulation probably by negatively affecting the capacity to synthesize downstream compounds. The accumulation of carotenoids induces chromoplast biogenesis through a metabolite-induced mechanism. Carotenogenic turnover flux can occur in non-photosynthetic tissues, which do not accumulate carotenoids. Arrest of this flux by the 'golden SNP' or other flux-arrest mutations is a potential tool for the biofortification of agricultural products with carotenoids.
Collapse
Affiliation(s)
- Ari Feder
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Noam Chayut
- Germplasm Resource Unit, John Innes Center, Norwich, United Kingdom
| | - Amit Gur
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Zohar Freiman
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Galil Tzuri
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Ayala Meir
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Uzi Saar
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Shachar Ohali
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Fabian Baumkoler
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Amit Gal-On
- Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Yula Shnaider
- Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Dalia Wolf
- Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Nurit Katzir
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Ari Schaffer
- Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Joseph Burger
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Li Li
- Robert W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY, United States
| | - Yaakov Tadmor
- Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
- *Correspondence: Yaakov Tadmor,
| |
Collapse
|
29
|
Welsch R, Zhou X, Koschmieder J, Schlossarek T, Yuan H, Sun T, Li L. Characterization of Cauliflower OR Mutant Variants. FRONTIERS IN PLANT SCIENCE 2019; 10:1716. [PMID: 32038686 PMCID: PMC6985574 DOI: 10.3389/fpls.2019.01716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 12/05/2019] [Indexed: 05/19/2023]
Abstract
Cauliflower Orange (Or) mutant is characterized by high level of β-carotene in its curd. Or mutation affects the OR protein that was shown to be involved in the posttranslational control of phytoene synthase (PSY), a major rate-limiting enzyme of carotenoid biosynthesis, and in maintaining PSY proteostasis with the plastid Clp protease system. A transposon integration into the cauliflower wild-type Or gene (BoOR-wt) results in the formation of three differently spliced transcripts. One of them is characterized by insertion (BoOR-Ins), while the other two have exon-skipping deletions (BoOR-Del and BoOR-LD). We investigated the properties of individual BoOR variants and examined their effects on carotenoid accumulation. Using the yeast split-ubiquitin system, we showed that all variants were able to form OR dimers except BoOR-LD. The deletion in BoOR-LD eliminated the first of two adjacent transmembrane domains and was predicted to result in a misplacement of the C-terminal zinc finger domain to the opposite side of membrane, thus preventing OR dimerization. As interaction with PSY is mediated by the N-terminus of BoOR, which remains unaffected after splicing, all BoOR variants including BoOR-LD maintained interactions with PSY. Expression of individual BoOR mutant variants in Arabidopsis revealed that their protein stability varied greatly. While expression of BoOR-Del and BoOR-Ins resulted in increased BoOR protein levels as BoOR-wt, minimal amounts of BoOR-LD protein accumulated. Carotenoid accumulation showed correlated changes in calli of Arabidopsis expressing these variants. Furthermore, we found that OR also functions in E. coli to increase the proportion of native, enzymatically active PSY from plants upon co-expression, but not of bacterial phytoene synthase CrtB. Taken together, these results suggest that OR dimerization is required for OR stability in planta and that the simultaneous presence of PSY interaction-domains in both OR and PSY proteins is required for the holdase function of OR. The more pronounced effect of simultaneous expression of all BoOR variants in cauliflower Or mutant compared with individual overexpression on carotenoid accumulation suggests an enhanced activity with possible formation of various BoOR heterodimers.
Collapse
Affiliation(s)
- Ralf Welsch
- Faculty of Biology II, University of Freiburg, Freiburg, Germany
- *Correspondence: Ralf Welsch, ; Li Li,
| | - Xiangjun Zhou
- Robert W. Holley Center for Agriculture and Health, Agricultural Research Service, US Department of Agriculture, Cornell University, Ithaca, NY, United States
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | | | - Tim Schlossarek
- Faculty of Biology II, University of Freiburg, Freiburg, Germany
| | - Hui Yuan
- Robert W. Holley Center for Agriculture and Health, Agricultural Research Service, US Department of Agriculture, Cornell University, Ithaca, NY, United States
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Tianhu Sun
- Robert W. Holley Center for Agriculture and Health, Agricultural Research Service, US Department of Agriculture, Cornell University, Ithaca, NY, United States
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Li Li
- Robert W. Holley Center for Agriculture and Health, Agricultural Research Service, US Department of Agriculture, Cornell University, Ithaca, NY, United States
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
- *Correspondence: Ralf Welsch, ; Li Li,
| |
Collapse
|