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Chustecki JM, Johnston IG. Collective mitochondrial dynamics resolve conflicting cellular tensions: From plants to general principles. Semin Cell Dev Biol 2024; 156:253-265. [PMID: 38043948 DOI: 10.1016/j.semcdb.2023.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/18/2023] [Accepted: 09/15/2023] [Indexed: 12/05/2023]
Abstract
Mitochondria play diverse and essential roles in eukaryotic cells, and plants are no exception. Plant mitochondria have several differences from their metazoan and fungal cousins: they often exist in a fragmented state, move rapidly on actin rather than microtubules, have many plant-specific metabolic features and roles, and usually contain only a subset of the complete mtDNA genome, which itself undergoes frequent recombination. This arrangement means that exchange and complementation is essential for plant mitochondria, and recent work has begun to reveal how their collective dynamics and resultant "social networks" of encounters support this exchange, connecting plant mitochondria in time rather than in space. This review will argue that this social network perspective can be extended to a "societal network", where mitochondrial dynamics are an essential part of the interacting cellular society of organelles and biomolecules. Evidence is emerging that mitochondrial dynamics allow optimal resolutions to competing cellular priorities; we will survey this evidence and review potential future research directions, highlighting that plant mitochondria can help reveal and test principles that apply across other kingdoms of life. In parallel with this fundamental cell biology, we also highlight the translational "One Health" importance of plant mitochondrial behaviour - which is exploited in the production of a vast amount of crops consumed worldwide - and the potential for multi-objective optimisation to understand and rationally re-engineer the evolved resolutions to these tensions.
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Affiliation(s)
- Joanna M Chustecki
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Iain G Johnston
- Department of Mathematics, University of Bergen, Bergen, Norway; Computational Biology Unit, University of Bergen, Bergen, Norway.
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Bhattacharya O, Ortiz I, Hendricks N, Walling LL. The tomato chloroplast stromal proteome compendium elucidated by leveraging a plastid protein-localization prediction Atlas. FRONTIERS IN PLANT SCIENCE 2023; 14:1020275. [PMID: 37701797 PMCID: PMC10493611 DOI: 10.3389/fpls.2023.1020275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 06/22/2023] [Indexed: 09/14/2023]
Abstract
Tomato (Solanum lycopersicum) is a model species for studying fruit development, wounding, herbivory, and pathogen attack. Despite tomato's world-wide economic importance and the role of chloroplasts as metabolic hubs and integrators of environmental cues, little is known about the stromal proteome of tomato. Using a high-yielding protocol for chloroplast and stromal protein isolation, MudPIT nano-LC-MS/MS analyses, a robust in-house protein database (the Atlas) for predicting the plastid localization of tomato proteins, and rigorous selection criteria for inclusion/exclusion in the stromal proteome, we identified 1,278 proteins of the tomato stromal proteome. We provide one of the most robust stromal proteomes available to date with empirical evidence for 545 and 92 proteins not previously described for tomato plastids and the Arabidopsis stroma, respectively. The relative abundance of tomato stromal proteins was determined using the exponentially modified protein abundance index (emPAI). Comparison of the abundance of tomato and Arabidopsis stromal proteomes provided evidence for the species-specific nature of stromal protein homeostasis. The manual curation of the tomato stromal proteome classified proteins into ten functional categories resulting in an accessible compendium of tomato chloroplast proteins. After curation, only 91 proteins remained as unknown, uncharacterized or as enzymes with unknown functions. The curation of the tomato stromal proteins also indicated that tomato has a number of paralogous proteins, not present in Arabidopsis, which accumulated to different levels in chloroplasts. As some of these proteins function in key metabolic pathways or in perceiving or transmitting signals critical for plant adaptation to biotic and abiotic stress, these data suggest that tomato may modulate the bidirectional communication between chloroplasts and nuclei in a novel manner. The stromal proteome provides a fertile ground for future mechanistic studies in the field of tomato chloroplast-nuclear signaling and are foundational for our goal of elucidating the dynamics of the stromal proteome controlled by the solanaceous-specific, stromal, and wound-inducible leucine aminopeptidase A of tomato.
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Affiliation(s)
- Oindrila Bhattacharya
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
| | - Irma Ortiz
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
| | - Nathan Hendricks
- Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | - Linda L. Walling
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
- Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
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Lee S, Vemanna RS, Oh S, Rojas CM, Oh Y, Kaundal A, Kwon T, Lee HK, Senthil-Kumar M, Mysore KS. Functional role of formate dehydrogenase 1 (FDH1) for host and nonhost disease resistance against bacterial pathogens. PLoS One 2022; 17:e0264917. [PMID: 35594245 PMCID: PMC9122214 DOI: 10.1371/journal.pone.0264917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 02/21/2022] [Indexed: 11/24/2022] Open
Abstract
Nonhost disease resistance is the most common type of plant defense mechanism against potential pathogens. In the present study, the metabolic enzyme formate dehydrogenase 1 (FDH1) was identified to associate with nonhost disease resistance in Nicotiana benthamiana and Arabidopsis thaliana. In Arabidopsis, AtFDH1 was highly upregulated in response to both host and nonhost bacterial pathogens. The Atfdh1 mutants were compromised in nonhost resistance, basal resistance, and gene-for-gene resistance. The expression patterns of salicylic acid (SA) and jasmonic acid (JA) marker genes after pathogen infections in Atfdh1 mutant indicated that both SA and JA are involved in the FDH1-mediated plant defense response to both host and nonhost bacterial pathogens. Previous studies reported that FDH1 localizes to mitochondria, or both mitochondria and chloroplasts. Our results showed that the AtFDH1 mainly localized to mitochondria, and the expression level of FDH1 was drastically increased upon infection with host or nonhost pathogens. Furthermore, we identified the potential co-localization of mitochondria expressing FDH1 with chloroplasts after the infection with nonhost pathogens in Arabidopsis. This finding suggests the possible role of FDH1 in mitochondria and chloroplasts during defense responses against bacterial pathogens in plants.
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Affiliation(s)
- Seonghee Lee
- Noble Research Institute, LLC, Ardmore, OK, United States of America
- Gulf Coast Research and Education Center, Institute of Food and Agricultural Science, University of Florida, Wimauma, FL, United States of America
| | - Ramu S. Vemanna
- Noble Research Institute, LLC, Ardmore, OK, United States of America
| | - Sunhee Oh
- Noble Research Institute, LLC, Ardmore, OK, United States of America
| | | | - Youngjae Oh
- Gulf Coast Research and Education Center, Institute of Food and Agricultural Science, University of Florida, Wimauma, FL, United States of America
| | - Amita Kaundal
- Noble Research Institute, LLC, Ardmore, OK, United States of America
| | - Taegun Kwon
- Noble Research Institute, LLC, Ardmore, OK, United States of America
| | - Hee-Kyung Lee
- Noble Research Institute, LLC, Ardmore, OK, United States of America
| | | | - Kirankumar S. Mysore
- Noble Research Institute, LLC, Ardmore, OK, United States of America
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, United States of America
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, United States of America
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Bhattacharya O, Ortiz I, Walling LL. Methodology: an optimized, high-yield tomato leaf chloroplast isolation and stroma extraction protocol for proteomics analyses and identification of chloroplast co-localizing proteins. PLANT METHODS 2020; 16:131. [PMID: 32983250 PMCID: PMC7513546 DOI: 10.1186/s13007-020-00667-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/04/2020] [Indexed: 06/09/2023]
Abstract
BACKGROUND Chloroplasts are critical organelles that perceive and convey metabolic and stress signals to different cellular components, while remaining the seat of photosynthesis and a metabolic factory. The proteomes of intact leaves, chloroplasts, and suborganellar fractions of plastids have been evaluated in the model plant Arabidopsis, however fewer studies have characterized the proteomes of plastids in crops. Tomato (Solanum lycopersicum) is an important world-wide crop and a model system for the study of wounding, herbivory and fruit ripening. While significant advances have been made in understanding proteome and metabolome changes in fruit ripening, far less is known about the tomato chloroplast proteome or its subcompartments. RESULTS With the long-term goal of understanding chloroplast proteome dynamics in response to stress, we describe a high-yielding method to isolate intact tomato chloroplasts and stromal proteins for proteomic studies. The parameters that limit tomato chloroplast yields were identified and revised to increase yields. Compared to published data, our optimized method increased chloroplast yields by 6.7- and 4.3-fold relative to published spinach and Arabidopsis leaf protocols, respectively; furthermore, tomato stromal protein yields were up to 79-fold higher than Arabidopsis stromal proteins yields. We provide immunoblot evidence for the purity of the stromal proteome isolated using our enhanced methods. In addition, we leverage our nanoliquid chromatography tandem mass spectrometry (nanoLC-MS/MS) data to assess the quality of our stromal proteome. Using strict criteria, proteins detected by 1 peptide spectral match, by one peptide, or were sporadically detected were designated as low-level contaminating proteins. A set of 254 proteins that reproducibly co-isolated with the tomato chloroplast stroma were identified. The subcellular localization, frequency of detection, normalized spectral abundance, and functions of the co-isolating proteins are discussed. CONCLUSIONS Our optimized method for chloroplast isolation increased the yields of tomato chloroplasts eightfold enabling the proteomics analysis of the chloroplast stromal proteome. The set of 254 proteins that co-isolate with the chloroplast stroma provides opportunities for developing a better understanding of the extensive and dynamic interactions of chloroplasts with other organelles. These co-isolating proteins also have the potential for expanding our knowledge of proteins that are co-localized in multiple subcellular organelles.
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Affiliation(s)
- Oindrila Bhattacharya
- Department of Botany and Plant Sciences, Center for Plant Cell Biology, University of California, Riverside, CA 92521 USA
| | - Irma Ortiz
- Department of Botany and Plant Sciences, Center for Plant Cell Biology, University of California, Riverside, CA 92521 USA
| | - Linda L. Walling
- Department of Botany and Plant Sciences, Center for Plant Cell Biology, University of California, Riverside, CA 92521 USA
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Zhang Y, Sampathkumar A, Kerber SML, Swart C, Hille C, Seerangan K, Graf A, Sweetlove L, Fernie AR. A moonlighting role for enzymes of glycolysis in the co-localization of mitochondria and chloroplasts. Nat Commun 2020; 11:4509. [PMID: 32908151 PMCID: PMC7481185 DOI: 10.1038/s41467-020-18234-w] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 08/11/2020] [Indexed: 12/15/2022] Open
Abstract
Glycolysis is one of the primordial pathways of metabolism, playing a pivotal role in energy metabolism and biosynthesis. Glycolytic enzymes are known to form transient multi-enzyme assemblies. Here we examine the wider protein-protein interactions of plant glycolytic enzymes and reveal a moonlighting role for specific glycolytic enzymes in mediating the co-localization of mitochondria and chloroplasts. Knockout mutation of phosphoglycerate mutase or enolase resulted in a significantly reduced association of the two organelles. We provide evidence that phosphoglycerate mutase and enolase form a substrate-channelling metabolon which is part of a larger complex of proteins including pyruvate kinase. These results alongside a range of genetic complementation experiments are discussed in the context of our current understanding of chloroplast-mitochondrial interactions within photosynthetic eukaryotes.
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Affiliation(s)
- Youjun Zhang
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
- Center of Plant Systems Biology and Biotechnology, 4000, Plovdiv, Bulgaria.
| | - Arun Sampathkumar
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Sandra Mae-Lin Kerber
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Corné Swart
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Carsten Hille
- Department of Physical Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476, Potsdam-Golm, Germany
- Technical University of Applied Sciences Wildau, Hochschulring 1, 15745, Wildau, Germany
| | - Kumar Seerangan
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Alexander Graf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Lee Sweetlove
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
- Center of Plant Systems Biology and Biotechnology, 4000, Plovdiv, Bulgaria.
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Sharaf A, Füssy Z, Tomčala A, Richtová J, Oborník M. Isolation of plastids and mitochondria from Chromera velia. PLANTA 2019; 250:1731-1741. [PMID: 31422509 DOI: 10.1007/s00425-019-03259-3] [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: 06/19/2019] [Accepted: 08/08/2019] [Indexed: 06/10/2023]
Abstract
We present an easy and effective procedure to purify plastids and mitochondria from Chromera velia. Our method enables downstream analyses of protein and metabolite content of the organelles. Chromerids are alveolate algae that are the closest known phototrophic relatives to apicomplexan parasites such as Plasmodium or Toxoplasma. While genomic and transcriptomic resources for chromerids are in place, tools and experimental conditions for proteomic studies have not been developed yet. Here we describe a rapid and efficient protocol for simultaneous isolation of plastids and mitochondria from the chromerid alga Chromera velia. This procedure involves enzymatic treatment and breakage of cells, followed by differential centrifugation. While plastids sediment in the first centrifugation step, mitochondria remain in the supernatant. Subsequently, plastids can be purified from the crude pellet by centrifugation on a discontinuous 60%/70% sucrose density gradient, while mitochondria can be obtained by centrifugation on a discontinuous 33%/80% Percoll density gradient. Isolated plastids are autofluorescent, and their multi-membrane structure was confirmed by transmission electron microscopy. Fluorescent optical microscopy was used to identify isolated mitochondria stained with MitoTrackerTM green, while their intactness and membrane potential were confirmed by staining with MitoTrackerTM orange CMTMRos. Total proteins were extracted from isolated organellar fractions, and the purity of isolated organelles was confirmed using immunoblotting. Antibodies against the beta subunit of the mitochondrial ATP synthase and the plastid protochlorophyllide oxidoreductase did not cross-react on immunoblots, suggesting that each organellar fraction is free of the residues of the other. The presented protocol represents an essential step for further proteomic, organellar, and cell biological studies of C. velia and can be employed, with minor optimizations, in other thick-walled unicellular algae.
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Affiliation(s)
- Abdoallah Sharaf
- Institute of Parasitology, Biology Centre CAS, Branišovská 31, 37005, České Budějovice, Czech Republic.
- Genetic Department, Faculty of Agriculture, Ain Shams University, Cairo, 11241, Egypt.
| | - Zoltán Füssy
- Institute of Parasitology, Biology Centre CAS, Branišovská 31, 37005, České Budějovice, Czech Republic
| | - Aleš Tomčala
- Institute of Parasitology, Biology Centre CAS, Branišovská 31, 37005, České Budějovice, Czech Republic
| | - Jitka Richtová
- Institute of Parasitology, Biology Centre CAS, Branišovská 31, 37005, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 37005, České Budějovice, Czech Republic
| | - Miroslav Oborník
- Institute of Parasitology, Biology Centre CAS, Branišovská 31, 37005, České Budějovice, Czech Republic.
- Faculty of Science, University of South Bohemia, Branišovská 31, 37005, České Budějovice, Czech Republic.
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Oikawa K, Hayashi M, Hayashi Y, Nishimura M. Re-evaluation of physical interaction between plant peroxisomes and other organelles using live-cell imaging techniques. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2019; 61:836-852. [PMID: 30916439 DOI: 10.1111/jipb.12805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
The dynamic behavior of organelles is essential for plant survival under various environmental conditions. Plant organelles, with various functions, migrate along actin filaments and contact other types of organelles, leading to physical interactions at a specific site called the membrane contact site. Recent studies have revealed the importance of physical interactions in maintaining efficient metabolite flow between organelles. In this review, we first summarize peroxisome function under different environmental conditions and growth stages to understand organelle interactions. We then discuss current knowledge regarding the interactions between peroxisome and other organelles, i.e., the oil bodies, chloroplast, and mitochondria from the perspective of metabolic and physiological regulation, with reference to various organelle interactions and techniques for estimating organelle interactions occurring in plant cells.
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Affiliation(s)
- Kazusato Oikawa
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Makoto Hayashi
- Department of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-Cho, Nagahama, 526-0829, Japan
| | - Yasuko Hayashi
- Department of Biology, Faculty of science, Niigata University, Niigata, 950-2181, Japan
| | - Mikio Nishimura
- Department of Cell Biology, National Institute for Basic Biology, Okazaki, 444-8585, Japan
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Welchen E, García L, Mansilla N, Gonzalez DH. Coordination of plant mitochondrial biogenesis: keeping pace with cellular requirements. FRONTIERS IN PLANT SCIENCE 2014; 4:551. [PMID: 24409193 PMCID: PMC3884152 DOI: 10.3389/fpls.2013.00551] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 12/23/2013] [Indexed: 05/20/2023]
Abstract
Plant mitochondria are complex organelles that carry out numerous metabolic processes related with the generation of energy for cellular functions and the synthesis and degradation of several compounds. Mitochondria are semiautonomous and dynamic organelles changing in shape, number, and composition depending on tissue or developmental stage. The biogenesis of functional mitochondria requires the coordination of genes present both in the nucleus and the organelle. In addition, due to their central role, all processes held inside mitochondria must be finely coordinated with those in other organelles according to cellular demands. Coordination is achieved by transcriptional control of nuclear genes encoding mitochondrial proteins by specific transcription factors that recognize conserved elements in their promoter regions. In turn, the expression of most of these transcription factors is linked to developmental and environmental cues, according to the availability of nutrients, light-dark cycles, and warning signals generated in response to stress conditions. Among the signals impacting in the expression of nuclear genes, retrograde signals that originate inside mitochondria help to adjust mitochondrial biogenesis to organelle demands. Adding more complexity, several nuclear encoded proteins are dual localized to mitochondria and either chloroplasts or the nucleus. Dual targeting might establish a crosstalk between the nucleus and cell organelles to ensure a fine coordination of cellular activities. In this article, we discuss how the different levels of coordination of mitochondrial biogenesis interconnect to optimize the function of the organelle according to both internal and external demands.
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Affiliation(s)
- Elina Welchen
- Instituto de Agrobiotecnología del Litoral–Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional del LitoralSanta Fe, Argentina
- Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del LitoralSanta Fe, Argentina
- *Correspondence: Elina Welchen and Daniel H. Gonzalez, Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, CC 242 Paraje El Pozo, 3000 Santa Fe, Argentina e-mail: ;
| | - Lucila García
- Instituto de Agrobiotecnología del Litoral–Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional del LitoralSanta Fe, Argentina
- Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del LitoralSanta Fe, Argentina
| | - Natanael Mansilla
- Instituto de Agrobiotecnología del Litoral–Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional del LitoralSanta Fe, Argentina
- Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del LitoralSanta Fe, Argentina
| | - Daniel H. Gonzalez
- Instituto de Agrobiotecnología del Litoral–Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional del LitoralSanta Fe, Argentina
- Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del LitoralSanta Fe, Argentina
- *Correspondence: Elina Welchen and Daniel H. Gonzalez, Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, CC 242 Paraje El Pozo, 3000 Santa Fe, Argentina e-mail: ;
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Brychkova G, Grishkevich V, Fluhr R, Sagi M. An essential role for tomato sulfite oxidase and enzymes of the sulfite network in maintaining leaf sulfite homeostasis. PLANT PHYSIOLOGY 2013; 161:148-64. [PMID: 23148079 PMCID: PMC3532248 DOI: 10.1104/pp.112.208660] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 11/12/2012] [Indexed: 05/19/2023]
Abstract
Little is known about the homeostasis of sulfite levels, a cytotoxic by-product of plant sulfur turnover. By employing extended dark to induce catabolic pathways, we followed key elements of the sulfite network enzymes that include adenosine-5'-phosphosulfate reductase and the sulfite scavengers sulfite oxidase (SO), sulfite reductase, UDP-sulfoquinovose synthase, and β-mercaptopyruvate sulfurtransferases. During extended dark, SO was enhanced in tomato (Solanum lycopersicum) wild-type leaves, while the other sulfite network components were down-regulated. SO RNA interference plants lacking SO activity accumulated sulfite, resulting in leaf damage and mortality. Exogenous sulfite application induced up-regulation of the sulfite scavenger activities in dark-stressed or unstressed wild-type plants, while expression of the sulfite producer, adenosine-5'-phosphosulfate reductase, was down-regulated. Unstressed or dark-stressed wild-type plants were resistant to sulfite applications, but SO RNA interference plants showed sensitivity and overaccumulation of sulfite. Hence, under extended dark stress, SO activity is necessary to cope with rising endogenous sulfite levels. However, under nonstressed conditions, the sulfite network can control sulfite levels in the absence of SO activity. The novel evidence provided by the synchronous dark-induced turnover of sulfur-containing compounds, augmented by exogenous sulfite applications, underlines the role of SO and other sulfite network components in maintaining sulfite homeostasis, where sulfite appears to act as an orchestrating signal molecule.
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Dynamic Behavior of Double-Membrane-Bounded Organelles in Plant Cells. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2011; 286:181-222. [DOI: 10.1016/b978-0-12-385859-7.00004-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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