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Cacefo V, Ribas AF, Vieira LGE. Proline metabolism as a mechanism for the energy dissipation in VaP5CSF129A transgenic tobacco plants under water deficit. JOURNAL OF PLANT PHYSIOLOGY 2023; 283:153964. [PMID: 36917876 DOI: 10.1016/j.jplph.2023.153964] [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: 08/20/2022] [Revised: 02/28/2023] [Accepted: 03/02/2023] [Indexed: 06/18/2023]
Abstract
In plants, proline accumulation in cells is a common response to alleviate the stress caused by water deficits. It has been shown that foliar proline spraying, as well as its overaccumulation in transgenic plants can increase drought tolerance, as proline metabolism plays important roles in cell redox balance and on energy dissipation pathways. The aim of this work was to evaluate the role of exogenous proline application or its endogenous overproduction as a potential mechanism for energy dissipation. For this, wild-type and VaP5CSF129A transgenic tobacco plants were sprayed with proline (10 mM) and submitted to water deficit. Changes in plant physiology and biochemistry were evaluated. Transcriptional changes in the relative expression of genes involved in proline synthesis and catabolism, NAD (P)-dependent malate dehydrogenase (NAD(P)-MDH), alternative oxidase (AOX), and VaP5CSF129A transgene were measured. Exogenous proline reduced the negative effects of water deficit on photosynthetic activity in both genotypes; with the transgenic plants even less affected. Water deficit caused an increase in the relative expression of proline biosynthesis genes. On the other hand, the expression of catabolism genes decreased, primarily in transgenic plants. Exogenous proline reduced activity of the NADP-MDH enzyme and decreased expression of the AOX and NADP-MDH genes, mainly in transgenic plants under water stress. Finally, our results suggest that proline metabolism could act as a complementary/compensatory mechanism for the energy dissipation pathways in plants under water deficit.
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Affiliation(s)
- Viviane Cacefo
- Universidade do Oeste Paulista (UNOESTE), Pós Graduação em Produção Vegetal. Rodovia Raposo Tavares, Km 572, CEP 19067-175, Presidente Prudente, SP, Brazil; Universidade do Oeste Paulista (UNOESTE), Centro de Estudos em Ecofisiologia Vegetal do Oeste Paulista (CEVOP), Rodovia Raposo Tavares, Km 572, CEP 19067-175, Presidente Prudente, SP, Brazil.
| | - Alessandra Ferreira Ribas
- Universidade do Oeste Paulista (UNOESTE), Pós Graduação em Produção Vegetal. Rodovia Raposo Tavares, Km 572, CEP 19067-175, Presidente Prudente, SP, Brazil; Universidade Federal do Paraná (UFPR), Departamento de Fitotecnia e Fitossanidade, Rua dos Funcionários, 1540, Cabral, CEP 80035-050, Brazil.
| | - Luiz Gonzaga Esteves Vieira
- Universidade do Oeste Paulista (UNOESTE), Pós Graduação em Produção Vegetal. Rodovia Raposo Tavares, Km 572, CEP 19067-175, Presidente Prudente, SP, Brazil.
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2
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Garcia A, Gaju O, Bowerman AF, Buck SA, Evans JR, Furbank RT, Gilliham M, Millar AH, Pogson BJ, Reynolds MP, Ruan Y, Taylor NL, Tyerman SD, Atkin OK. Enhancing crop yields through improvements in the efficiency of photosynthesis and respiration. THE NEW PHYTOLOGIST 2023; 237:60-77. [PMID: 36251512 PMCID: PMC10100352 DOI: 10.1111/nph.18545] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/15/2022] [Indexed: 06/06/2023]
Abstract
The rate with which crop yields per hectare increase each year is plateauing at the same time that human population growth and other factors increase food demand. Increasing yield potential (Y p ) of crops is vital to address these challenges. In this review, we explore a component ofY p that has yet to be optimised - that being improvements in the efficiency with which light energy is converted into biomass (ε c ) via modifications to CO2 fixed per unit quantum of light (α), efficiency of respiratory ATP production (ε prod ) and efficiency of ATP use (ε use ). For α, targets include changes in photoprotective machinery, ribulose bisphosphate carboxylase/oxygenase kinetics and photorespiratory pathways. There is also potential forε prod to be increased via targeted changes to the expression of the alternative oxidase and mitochondrial uncoupling pathways. Similarly, there are possibilities to improveε use via changes to the ATP costs of phloem loading, nutrient uptake, futile cycles and/or protein/membrane turnover. Recently developed high-throughput measurements of respiration can serve as a proxy for the cumulative energy cost of these processes. There are thus exciting opportunities to use our growing knowledge of factors influencing the efficiency of photosynthesis and respiration to create a step-change in yield potential of globally important crops.
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Affiliation(s)
- Andres Garcia
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - Oorbessy Gaju
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- College of Science, Lincoln Institute for Agri‐Food TechnologyUniversity of LincolnLincolnshireLN2 2LGUK
| | - Andrew F. Bowerman
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - Sally A. Buck
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - John R. Evans
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
- ARC Centre of Excellence for Translational Photosynthesis, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
| | - Robert T. Furbank
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
- ARC Centre of Excellence for Translational Photosynthesis, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
| | - Matthew Gilliham
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine & Waite Research InstituteUniversity of AdelaideGlen OsmondSA5064Australia
| | - A. Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences & Institute of AgricultureThe University of Western AustraliaCrawleyWA6009Australia
| | - Barry J. Pogson
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - Matthew P. Reynolds
- International Maize and Wheat Improvement Center (CIMMYT)Km. 45, Carretera Mexico, El BatanTexcoco56237Mexico
| | - Yong‐Ling Ruan
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
| | - Nicolas L. Taylor
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Sciences & Institute of AgricultureThe University of Western AustraliaCrawleyWA6009Australia
| | - Stephen D. Tyerman
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine & Waite Research InstituteUniversity of AdelaideGlen OsmondSA5064Australia
| | - Owen K. Atkin
- ARC Centre of Excellence in Plant Energy Biology, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
- Division of Plant Sciences, Research School of BiologyAustralian National UniversityCanberraACT2601Australia
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Qiao K, Yao X, Zhou Z, Xiong J, Fang K, Lan J, Xu F, Deng X, Zhang D, Lin H. Mitochondrial alternative oxidase enhanced ABA-mediated drought tolerance in Solanum lycopersicum. JOURNAL OF PLANT PHYSIOLOGY 2023; 280:153892. [PMID: 36566671 DOI: 10.1016/j.jplph.2022.153892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/04/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
The phytohormone abscisic acid (ABA) plays essential roles in modulating drought stress responses. Mitochondrial alternative oxidase (AOX) is critical for reactive oxygen species (ROS) scavenging in drought stress responses. However, whether ABA signal in concert with AOX to moderate drought stress response remains largely unclear. In our study, we uncover the positive role of AOX in ABA-mediated drought tolerance in tomato (Solanum lycopersicum). Here, we report that ABA participates in the regulation of alternative respiration, and the increased AOX was found to improve drought tolerance by reducing total ROS accumulation. We also found that transcription factor ABA response element-binding factor 1 (SlAREB1) can directly bind to the promoter of AOX1a to activate its transcription. Virus-induced gene silencing (VIGS) of SlAREB1 compromised the ABA-induced alternative respiratory pathway, disrupted redox homeostasis and decreased plant resistance to drought stress, while overexpression of AOX1a in TRV2-SlAREB1 plants partially rescued the severe drought phenotype. Taken together, our results indicated that AOX1a plays an essential role in ABA-mediated drought tolerance partially in a SlAREB1-dependent manner, providing new insights into how ABA modulates ROS levels to cope with drought stress by AOX.
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Affiliation(s)
- Kang Qiao
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, China
| | - Xiuhong Yao
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, China
| | - Zuxu Zhou
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, China
| | - Jiawei Xiong
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, China
| | - Ke Fang
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, China
| | - Jiayi Lan
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, China
| | - Fei Xu
- Life Science and Biotechnology, Wuhan Bioengineering Institute, Wuhan, China
| | - Xingguang Deng
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, China
| | - Dawei Zhang
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, China.
| | - Honghui Lin
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, China.
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Wang X, Geng X, Bi X, Li R, Chen Y, Lu C. Genome-wide identification of AOX family genes in Moso bamboo and functional analysis of PeAOX1b_2 in drought and salinity stress tolerance. PLANT CELL REPORTS 2022; 41:2321-2339. [PMID: 36063182 DOI: 10.1007/s00299-022-02923-5] [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: 07/11/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
Five PeAOX genes from Moso bamboo genome were identified. PeAOX1b_2-OE improved tolerance to drought and salinity stress in Arabidopsis, indicating it is involved in positive regulation of abiotic stress response. Mitochondrial alternative oxidase (AOX), the important respiratory terminal oxidase in organisms, catalyzes the energy wasteful cyanide (CN)-resistant respiration, which can improve abiotic stresses tolerance and is considered as one of the functional markers for plant resistance breeding. Here, a total of five putative AOX genes (PeAOXs) were identified and characterized in a monocotyledonous woody grass Moso bamboo (Phyllostachys edulis). Phylogenetic analysis revealed that PeAOXs belonged to AOX1 subfamily, and were named PeAOX1a_1, PeAOX1a_2, PeAOX1b_1, PeAOX1b_2 and PeAOX1c, respectively. Evolutionary and divergence patterns analysis revealed that the PeAOX, OsAOX, and BdAOX families experienced positive purifying selection and may have undergone a large-scale duplication event roughly 1.35-155.90 million years ago. Additionally, the organ-specific expression analysis showed that 80% of PeAOX members were mainly expressed in leaf. Promoter sequence analysis of PeAOXs revealed cis-acting regulatory elements (CAREs) responding to abiotic stress. Most PeAOX genes were significantly upregulated after methyl jasmonate (MeJA) and abscisic acid (ABA) treatment. Moreover, under salinity and drought stresses, the ectopic overexpression of PeAOX1b_2 in Arabidopsis enhanced seed germination and seedling establishment, increased the total respiratory rate and the proportion of AOX respiratory pathway in leaf, and enhanced antioxidant ability, suggesting that PeAOX1b_2 is crucial for abiotic stress resistance in Moso bamboo.
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Affiliation(s)
- Xiaojing Wang
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China
| | - Xin Geng
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China
| | - Xiaorui Bi
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China
| | - Rongchen Li
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China
| | - Yuzhen Chen
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.
| | - Cunfu Lu
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.
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Sweetman C, Waterman CD, Wong DC, Day DA, Jenkins CL, Soole KL. Altering the balance between AOX1A and NDB2 expression affects a common set of transcripts in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2022; 13:876843. [PMID: 36466234 PMCID: PMC9716356 DOI: 10.3389/fpls.2022.876843] [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: 02/15/2022] [Accepted: 10/24/2022] [Indexed: 06/17/2023]
Abstract
Stress-responsive components of the mitochondrial alternative electron transport pathway have the capacity to improve tolerance of plants to abiotic stress, particularly the alternative oxidase AOX1A but also external NAD(P)H dehydrogenases such as NDB2, in Arabidopsis. NDB2 and AOX1A can cooperate to entirely circumvent the classical electron transport chain in Arabidopsis mitochondria. Overexpression of AOX1A or NDB2 alone can have slightly negative impacts on plant growth under optimal conditions, while simultaneous overexpression of NDB2 and AOX1A can reverse these phenotypic effects. We have taken a global transcriptomic approach to better understand the molecular shifts that occur due to overexpression of AOX1A alone and with concomitant overexpression of NDB2. Of the transcripts that were significantly up- or down- regulated in the AOX1A overexpression line compared to wild type (410 and 408, respectively), the majority (372 and 337, respectively) reverted to wild type levels in the dual overexpression line. Several mechanisms for the AOX1A overexpression phenotype are proposed based on the functional classification of these 709 genes, which can be used to guide future experiments. Only 28 genes were uniquely up- or down-regulated when NDB2 was overexpressed in the AOX1A overexpression line. On the other hand, many unique genes were deregulated in the NDB2 knockout line. Furthermore, several changes in transcript abundance seen in the NDB2 knockout line were consistent with changes in the AOX1A overexpression line. The results suggest that an imbalance in AOX1A:NDB2 protein levels caused by under- or over-expression of either component, triggers a common set of transcriptional responses that may be important in mitochondrial redox regulation. The most significant changes were transcripts associated with photosynthesis, secondary metabolism and oxidative stress responses.
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Affiliation(s)
- Crystal Sweetman
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
| | | | - Darren C.J. Wong
- College of Science, Australian National University, Canberra, ACT, Australia
| | - David A. Day
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
| | - Colin L.D. Jenkins
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
| | - Kathleen L. Soole
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
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Barreto P, Koltun A, Nonato J, Yassitepe J, Maia IDG, Arruda P. Metabolism and Signaling of Plant Mitochondria in Adaptation to Environmental Stresses. Int J Mol Sci 2022; 23:ijms231911176. [PMID: 36232478 PMCID: PMC9570015 DOI: 10.3390/ijms231911176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/29/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
The interaction of mitochondria with cellular components evolved differently in plants and mammals; in plants, the organelle contains proteins such as ALTERNATIVE OXIDASES (AOXs), which, in conjunction with internal and external ALTERNATIVE NAD(P)H DEHYDROGENASES, allow canonical oxidative phosphorylation (OXPHOS) to be bypassed. Plant mitochondria also contain UNCOUPLING PROTEINS (UCPs) that bypass OXPHOS. Recent work revealed that OXPHOS bypass performed by AOXs and UCPs is linked with new mechanisms of mitochondrial retrograde signaling. AOX is functionally associated with the NO APICAL MERISTEM transcription factors, which mediate mitochondrial retrograde signaling, while UCP1 can regulate the plant oxygen-sensing mechanism via the PRT6 N-Degron. Here, we discuss the crosstalk or the independent action of AOXs and UCPs on mitochondrial retrograde signaling associated with abiotic stress responses. We also discuss how mitochondrial function and retrograde signaling mechanisms affect chloroplast function. Additionally, we discuss how mitochondrial inner membrane transporters can mediate mitochondrial communication with other organelles. Lastly, we review how mitochondrial metabolism can be used to improve crop resilience to environmental stresses. In this respect, we particularly focus on the contribution of Brazilian research groups to advances in the topic of mitochondrial metabolism and signaling.
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Affiliation(s)
- Pedro Barreto
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências, Universidade Estadual Paulista, Botucatu 18618-970, Brazil
| | - Alessandra Koltun
- Genomics for Climate Change Research Center, Universidade Estadual de Campinas, Campinas 13083-875, Brazil
- Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas, Campinas 13083-862, Brazil
| | - Juliana Nonato
- Genomics for Climate Change Research Center, Universidade Estadual de Campinas, Campinas 13083-875, Brazil
- Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas, Campinas 13083-862, Brazil
| | - Juliana Yassitepe
- Genomics for Climate Change Research Center, Universidade Estadual de Campinas, Campinas 13083-875, Brazil
- Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas, Campinas 13083-862, Brazil
- Embrapa Agricultura Digital, Campinas 13083-886, Brazil
| | - Ivan de Godoy Maia
- Departamento de Ciências Químicas e Biológicas, Instituto de Biociências, Universidade Estadual Paulista, Botucatu 18618-970, Brazil
| | - Paulo Arruda
- Genomics for Climate Change Research Center, Universidade Estadual de Campinas, Campinas 13083-875, Brazil
- Departamento de Genética e Evolução, Instituto de Biologia, Universidade Estadual de Campinas, Campinas 13083-862, Brazil
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas 13083-875, Brazil
- Correspondence:
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Alhajhoj MR, Munir M, Sudhakar B, Ali-Dinar HM, Iqbal Z. Common and novel metabolic pathways related ESTs were upregulated in three date palm cultivars to ameliorate drought stress. Sci Rep 2022; 12:15027. [PMID: 36056140 PMCID: PMC9440037 DOI: 10.1038/s41598-022-19399-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
Date palm is an important staple crop in Saudi Arabia, and about 400 different date palm cultivars grown here, only 50-60 of them are used commercially. The most popular and commercially consumed cultivars of these are Khalas, Reziz, and Sheshi, which are also widely cultivated across the country. Date palm is high water-demanding crop in oasis agriculture, with an inherent ability to tolerate drought stress. However, the mechanisms by which it tolerates drought stress, especially at the transcriptomic level, are still elusive. This study appraised the physiological and molecular response of three commercial date palm cultivars Khalas, Reziz, and Sheshi at two different field capacities (FC; 100% and 25%) levels. At 25% FC (drought stress), leaf relative water content, chlorophyll, photosynthesis, stomatal conductance, and transpiration were significantly reduced. However, leaf intercellular CO2 concentration and water use efficiency increased under drought stress. In comparison to cvs. Khalas and Reziz, date palm cv. Sheshi showed less tolerance to drought stress. A total of 1118 drought-responsive expressed sequence tags (ESTs) were sequenced, 345 from Khalas, 391 from Reziz, and 382 from Sheshi and subjected to functional characterization, gene ontology classification, KEGG pathways elucidation, and enzyme codes dissemination. Three date palm cultivars deployed a multivariate approach to ameliorate drought stress by leveraging common and indigenous molecular, cellular, biological, structural, transcriptional and reproductive mechanisms. Approximately 50% of the annotated ESTs were related to photosynthesis regulation, photosynthetic structure, signal transduction, auxin biosynthesis, osmoregulation, stomatal conductance, protein synthesis/turnover, active transport of solutes, and cell structure modulation. Along with the annotated ESTs, ca. 45% of ESTs were novel. Conclusively, the study provides novel clues and opens the myriads of genetic resources to understand the fine-tuned drought amelioration mechanisms in date palm.
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Affiliation(s)
- Mohammed Refdan Alhajhoj
- Department of Arid Land Agriculture, College of Agriculture and Food Sciences, King Faisal University, PO Box 31982, Al-Ahsa, Saudi Arabia
| | - Muhammad Munir
- Date Palm Research Center of Excellence, King Faisal University, PO Box 31982, Al-Ahsa, Saudi Arabia
| | - Balakrishnan Sudhakar
- Date Palm Research Center of Excellence, King Faisal University, PO Box 31982, Al-Ahsa, Saudi Arabia
| | - Hassan Muzzamil Ali-Dinar
- Date Palm Research Center of Excellence, King Faisal University, PO Box 31982, Al-Ahsa, Saudi Arabia
| | - Zafar Iqbal
- Central Laboratories, King Faisal University, PO Box 31982, Al-Ahsa, Saudi Arabia.
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Fuchs P, Bohle F, Lichtenauer S, Ugalde JM, Feitosa Araujo E, Mansuroglu B, Ruberti C, Wagner S, Müller-Schüssele SJ, Meyer AJ, Schwarzländer M. Reductive stress triggers ANAC017-mediated retrograde signaling to safeguard the endoplasmic reticulum by boosting mitochondrial respiratory capacity. THE PLANT CELL 2022; 34:1375-1395. [PMID: 35078237 PMCID: PMC9125394 DOI: 10.1093/plcell/koac017] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 12/18/2021] [Indexed: 05/16/2023]
Abstract
Redox processes are at the heart of universal life processes, such as metabolism, signaling, or folding of secreted proteins. Redox landscapes differ between cell compartments and are strictly controlled to tolerate changing conditions and to avoid cell dysfunction. While a sophisticated antioxidant network counteracts oxidative stress, our understanding of reductive stress responses remains fragmentary. Here, we observed root growth impairment in Arabidopsis thaliana mutants of mitochondrial alternative oxidase 1a (aox1a) in response to the model thiol reductant dithiothreitol (DTT). Mutants of mitochondrial uncoupling protein 1 (ucp1) displayed a similar phenotype indicating that impaired respiratory flexibility led to hypersensitivity. Endoplasmic reticulum (ER) stress was enhanced in the mitochondrial mutants and limiting ER oxidoreductin capacity in the aox1a background led to synergistic root growth impairment by DTT, indicating that mitochondrial respiration alleviates reductive ER stress. The observations that DTT triggered nicotinamide adenine dinucleotide (NAD) reduction in vivo and that the presence of thiols led to electron transport chain activity in isolated mitochondria offer a biochemical framework of mitochondrion-mediated alleviation of thiol-mediated reductive stress. Ablation of transcription factor Arabidopsis NAC domain-containing protein17 (ANAC017) impaired the induction of AOX1a expression by DTT and led to DTT hypersensitivity, revealing that reductive stress tolerance is achieved by adjusting mitochondrial respiratory capacity via retrograde signaling. Our data reveal an unexpected role for mitochondrial respiratory flexibility and retrograde signaling in reductive stress tolerance involving inter-organelle redox crosstalk.
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Affiliation(s)
- Philippe Fuchs
- Institute of Plant Biology and Biotechnology (IBBP), Westfälische Wilhelms-Universität Münster, D-48143 Münster, Germany
- Institute of Crop Science and Resource Conservation (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, D-53113 Bonn, Germany
| | - Finja Bohle
- Institute of Crop Science and Resource Conservation (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, D-53113 Bonn, Germany
| | - Sophie Lichtenauer
- Institute of Plant Biology and Biotechnology (IBBP), Westfälische Wilhelms-Universität Münster, D-48143 Münster, Germany
| | - José Manuel Ugalde
- Institute of Crop Science and Resource Conservation (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, D-53113 Bonn, Germany
| | - Elias Feitosa Araujo
- Institute of Plant Biology and Biotechnology (IBBP), Westfälische Wilhelms-Universität Münster, D-48143 Münster, Germany
| | - Berivan Mansuroglu
- Institute of Crop Science and Resource Conservation (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, D-53113 Bonn, Germany
| | - Cristina Ruberti
- Institute of Plant Biology and Biotechnology (IBBP), Westfälische Wilhelms-Universität Münster, D-48143 Münster, Germany
| | - Stephan Wagner
- Institute of Plant Biology and Biotechnology (IBBP), Westfälische Wilhelms-Universität Münster, D-48143 Münster, Germany
- Institute of Crop Science and Resource Conservation (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, D-53113 Bonn, Germany
| | - Stefanie J Müller-Schüssele
- Institute of Crop Science and Resource Conservation (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, D-53113 Bonn, Germany
| | - Andreas J Meyer
- Institute of Crop Science and Resource Conservation (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, D-53113 Bonn, Germany
| | - Markus Schwarzländer
- Institute of Plant Biology and Biotechnology (IBBP), Westfälische Wilhelms-Universität Münster, D-48143 Münster, Germany
- Institute of Crop Science and Resource Conservation (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, D-53113 Bonn, Germany
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9
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Oh GGK, O’Leary BM, Signorelli S, Millar AH. Alternative oxidase (AOX) 1a and 1d limit proline-induced oxidative stress and aid salinity recovery in Arabidopsis. PLANT PHYSIOLOGY 2022; 188:1521-1536. [PMID: 34919733 PMCID: PMC8896607 DOI: 10.1093/plphys/kiab578] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 11/12/2021] [Indexed: 05/24/2023]
Abstract
Proline (Pro) catabolism and reactive oxygen species production have been linked in mammals and Caenorhabditis elegans, while increases in leaf respiration rate follow Pro exposure in plants. Here, we investigated how alternative oxidases (AOXs) of the mitochondrial electron transport chain accommodate the large, atypical flux resulting from Pro catabolism and limit oxidative stress during Pro breakdown in mature Arabidopsis (Arabidopsis thaliana) leaves. Following Pro treatment, AOX1a and AOX1d accumulate at transcript and protein levels, with AOX1d approaching the level of the typically dominant AOX1a isoform. We therefore sought to determine the function of both AOX isoforms under Pro respiring conditions. Oxygen consumption rate measurements in aox1a and aox1d leaves suggested these AOXs can functionally compensate for each other to establish enhanced AOX catalytic capacity in response to Pro. Generation of aox1a.aox1d lines showed complete loss of AOX proteins and activity upon Pro treatment, yet full respiratory induction in response to Pro remained possible via the cytochrome pathway. However, aox1a.aox1d leaves displayed symptoms of elevated oxidative stress and suffered increased oxidative damage during Pro metabolism compared to the wild-type (WT) or the single mutants. During recovery from salt stress, when relatively high rates of Pro catabolism occur naturally, photosynthetic rates in aox1a.aox1d recovered slower than in the WT or the single aox lines, showing that both AOX1a and AOX1d are beneficial for cellular metabolism during Pro drawdown following osmotic stress. This work provides physiological evidence of a beneficial role for AOX1a but also the less studied AOX1d isoform in allowing safe catabolism of alternative respiratory substrates like Pro.
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Affiliation(s)
- Glenda Guek Khim Oh
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Crawley WA 6009, Australia
| | - Brendan M O’Leary
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Crawley WA 6009, Australia
- Saskatoon Research and Development Centre, Agriculture and Agri-food, Saskatoon, SK S7N 0X2, Canada
| | - Santiago Signorelli
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Crawley WA 6009, Australia
- Laboratorio de Bioquímica, Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Uruguay
| | - A Harvey Millar
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, Crawley WA 6009, Australia
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How to Cope with the Challenges of Environmental Stresses in the Era of Global Climate Change: An Update on ROS Stave off in Plants. Int J Mol Sci 2022; 23:ijms23041995. [PMID: 35216108 PMCID: PMC8879091 DOI: 10.3390/ijms23041995] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/30/2022] [Accepted: 02/06/2022] [Indexed: 02/06/2023] Open
Abstract
With the advent of human civilization and anthropogenic activities in the shade of urbanization and global climate change, plants are exposed to a complex set of abiotic stresses. These stresses affect plants’ growth, development, and yield and cause enormous crop losses worldwide. In this alarming scenario of global climate conditions, plants respond to such stresses through a highly balanced and finely tuned interaction between signaling molecules. The abiotic stresses initiate the quick release of reactive oxygen species (ROS) as toxic by-products of altered aerobic metabolism during different stress conditions at the cellular level. ROS includes both free oxygen radicals {superoxide (O2•−) and hydroxyl (OH−)} as well as non-radicals [hydrogen peroxide (H2O2) and singlet oxygen (1O2)]. ROS can be generated and scavenged in different cell organelles and cytoplasm depending on the type of stimulus. At high concentrations, ROS cause lipid peroxidation, DNA damage, protein oxidation, and necrosis, but at low to moderate concentrations, they play a crucial role as secondary messengers in intracellular signaling cascades. Because of their concentration-dependent dual role, a huge number of molecules tightly control the level of ROS in cells. The plants have evolved antioxidants and scavenging machinery equipped with different enzymes to maintain the equilibrium between the production and detoxification of ROS generated during stress. In this present article, we have focused on current insights on generation and scavenging of ROS during abiotic stresses. Moreover, the article will act as a knowledge base for new and pivotal studies on ROS generation and scavenging.
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Gervais T, Creelman A, Li XQ, Bizimungu B, De Koeyer D, Dahal K. Potato Response to Drought Stress: Physiological and Growth Basis. FRONTIERS IN PLANT SCIENCE 2021; 12:698060. [PMID: 34456939 PMCID: PMC8387673 DOI: 10.3389/fpls.2021.698060] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
Drought poses a major challenge to the production of potatoes worldwide. Climate change is predicted to further aggravate this challenge by intensifying potato crop exposure to increased drought severity and frequency. There is an ongoing effort to adapt our production systems of potatoes through the development of drought-tolerant cultivars that are appropriately engineered for the changing environment. The breeding of drought-tolerant cultivars can be approached through the identification of drought-related physiological and biochemical traits and their deployment in new potato cultivars. Thus, the main objective of this study was to develop a method to identify and characterize the drought-tolerant potato genotypes and the related key traits. To achieve this objective, first we studied 56 potato genotypes including 54 cultivars and 2 advanced breeding lines to assess drought tolerance in terms of tuber yield in the greenhouse experiment. Drought differentially reduced tuber yield in all genotypes. Based on their capacity to maintain percent tuber yield under drought relative to their well-watered controls, potato genotypes differed in their ability to tolerate drought. We then selected six genotypes, Bannock Russet, Nipigon, Onaway, Denali, Fundy, and Russet Norkotah, with distinct yield responses to drought to further examine the physiological and biochemical traits governing drought tolerance. The drought-induced reduction in tuber yield was only 15-20% for Bannock Russet and Nipigon, 44-47% for Onaway and Denali, and 83-91% for Fundy and Russet Norkotah. The tolerant genotypes, Bannock Russet and Nipigon, exhibited about a 2-3-fold increase in instantaneous water-use efficiency (WUE) under drought as compared with their well-watered controls. This stimulation was about 1.8-2-fold for moderately tolerant genotypes, Onaway and Denali, and only 1.5-fold for sensitive genotypes, Fundy, and Russet Norkotah. The differential stimulation of instantaneous WUE of tolerant and moderately tolerant genotypes vs. sensitive genotypes was accounted for by the differential suppression of the rates of photosynthesis, stomatal conductance, and transpiration rates across genotypes. Potato genotypes varied in their response to leaf protein content under drought. We suggest that the rates of photosynthesis, instantaneous WUE, and leaf protein content can be used as the selection criteria for the drought-tolerant potato genotypes.
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Tcherkez G, Atkin OK. Unravelling mechanisms and impacts of day respiration in plant leaves: an introduction to a Virtual Issue. THE NEW PHYTOLOGIST 2021; 230:5-10. [PMID: 33650185 DOI: 10.1111/nph.17164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 12/23/2020] [Indexed: 06/12/2023]
Affiliation(s)
- Guillaume Tcherkez
- Division of Plant Sciences, Research School of Biology, ANU College of Science, Australian National University, Canberra, ACT, 2601, Australia
| | - Owen K Atkin
- Division of Plant Sciences, Research School of Biology, ANU College of Science, Australian National University, Canberra, ACT, 2601, Australia
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Li YT, Liu MJ, Li Y, Liu P, Zhao SJ, Gao HY, Zhang ZS. Photoprotection by mitochondrial alternative pathway is enhanced at heat but disabled at chilling. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:403-415. [PMID: 32683757 DOI: 10.1111/tpj.14931] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 07/01/2020] [Accepted: 07/06/2020] [Indexed: 05/02/2023]
Abstract
The mitochondrial alternative pathway (AP) represents an important photoprotective mechanism for the chloroplast, but the temperature sensitivity of its photoprotective role is unknown. In this study, using the aox1a Arabidopsis mutant, the photoprotective role of the AP was verified under various temperatures, and the mechanism underlying the temperature sensitivity of the AP's photoprotective role was clarified. It was observed that the photoprotective role of the AP increased with rising temperature but was absent at low temperature. The photoprotective role of the AP was severely reduced under non-photorespiratory conditions. Disturbance of the AP inhibited the conversion of glycine to serine in mitochondria, which may restrain upstream photorespiratory metabolism and aggravate photoinhibition. With rising temperatures, photorespiration accelerated and the restraint of photorespiration caused by disturbance of the AP also increased, determining the temperature sensitivity of the AP's photoprotective role. We also verified that not only the AP but also the cytochrome pathway in mitochondria contributes to photoprotection by maintaining photorespiration.
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Affiliation(s)
- Yu-Ting Li
- State Key Lab of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Mei-Jun Liu
- Key laboratory of Grassland Resources and Ecology of Xinjiang, College of Grassland and Environment Science, Xinjiang Agricultural University, Urumqi, Xinjiang, 830052, China
| | - Ying Li
- State Key Lab of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Peng Liu
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Shi-Jie Zhao
- State Key Lab of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Hui-Yuan Gao
- State Key Lab of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Zi-Shan Zhang
- State Key Lab of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
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Distinct roles of alternative oxidase pathway during the greening process of etiolated algae. SCIENCE CHINA-LIFE SCIENCES 2020; 64:816-827. [PMID: 32712832 DOI: 10.1007/s11427-020-1755-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 05/09/2020] [Indexed: 12/19/2022]
Abstract
The vital function of mitochondrial alternative oxidase (AOX) pathway in optimizing photosynthesis during plant de-etiolation has been well recognized. However, whether and how AOX impacts the chloroplast biogenesis in algal cells remains unclear. In the present study, the role of AOX in regulating the reassembly of chloroplast in algal cells was investigated by treating Auxenochlorella protothecoides with salicylhydroxamic acid (SHAM), the specific inhibitor to AOX, in the heterotrophy to autotrophy transition process. Several lines of evidences including delayed chlorophyll accumulation, lagged reorganization of chloroplast structure, altered PSI/PSII stoichiometry, and declined photosynthetic activities in SHAM treated cells indicated that the impairment in AOX activity dramatically hindered the development of functioning chloroplast in algal cells. Besides, the cellular ROS levels and activities of antioxidant enzymes were increased by SHAM treatment, and the perturbation on the balance of NAD+/NADH and NADP+/NADPH ratios was also observed in A. protothecoides lacking AOX activity, indicating that AOX was essential in promoting ROS scavenging and keeping the redox homeostasis for algal chloroplast development during greening. Overall, our study revealed the essentiality of mitochondrial AOX pathway in sustaining algal photosynthetic performance and provided novel insights into the physiological roles of AOX on the biogenesis of photosynthetic organelle in algae.
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Lv Y, Li Y, Liu X, Xu K. Photochemistry and proteomics of ginger (Zingiber officinale Roscoe) under drought and shading. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 151:188-196. [PMID: 32224390 DOI: 10.1016/j.plaphy.2020.03.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 03/17/2020] [Accepted: 03/17/2020] [Indexed: 05/20/2023]
Abstract
Drought has become an increasingly serious ecological problem that limits crop production. However, little is known about the response of ginger (Zingiber officinale Roscoe) to drought and shading, especially with respect to photosynthetic electron transport. Here, differential proteomics was used to study the response of ginger to four experimental treatments: control, drought, 50% shading, and the combination of 50% shading and drought. Proteomic analysis suggested that ginger increased cyclic electron flow under drought stress by enhancing the expression of proteins related to photosystem I and cytochrome b6f. Shading significantly increased the expression of proteins related to the light harvesting complex, even under drought stress. In addition, shading increased the expression of proteins related to the oxygen evolution complex, plastocyanin, and ferredoxin-NADP+ reductase (FNR), thereby enhancing the efficiency of photosynthetic electron utilization. The shading and drought combination treatment appeared to enhance ginger's drought tolerance by reducing the expression of FNR and enhancing cyclic electron flow. Photosynthetic and fluorescence parameters showed that drought stress caused non-stomatal limitation of photosynthesis in ginger leaves. Drought stress also significantly reduced the quantum efficiency of photosystem II (Fv/Fm), the non-cyclic electron transfer efficiency of photosystem II (ϕPSII), and photochemical quenching (qP), while simultaneously increasing nonphotochemical quenching (NPQ). The addition of shading improved photosynthetic efficiency under drought. These results provide important baseline information on the photosynthetic mechanisms by which ginger responds to drought and shading. In addition, they provide a theoretical basis for the study of shade cultivation during the arid season.
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Affiliation(s)
- Yao Lv
- College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, 271018, China
| | - Yanyan Li
- College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, 271018, China
| | - Xiaohui Liu
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Kun Xu
- College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, 271018, China.
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Sweetman C, Miller TK, Booth NJ, Shavrukov Y, Jenkins CL, Soole KL, Day DA. Identification of Alternative Mitochondrial Electron Transport Pathway Components in Chickpea Indicates a Differential Response to Salinity Stress between Cultivars. Int J Mol Sci 2020; 21:E3844. [PMID: 32481694 PMCID: PMC7312301 DOI: 10.3390/ijms21113844] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 11/16/2022] Open
Abstract
All plants contain an alternative electron transport pathway (AP) in their mitochondria, consisting of the alternative oxidase (AOX) and type 2 NAD(P)H dehydrogenase (ND) families, that are thought to play a role in controlling oxidative stress responses at the cellular level. These alternative electron transport components have been extensively studied in plants like Arabidopsis and stress inducible isoforms identified, but we know very little about them in the important crop plant chickpea. Here we identify AP components in chickpea (Cicer arietinum) and explore their response to stress at the transcript level. Based on sequence similarity with the functionally characterized proteins of Arabidopsis thaliana, five putative internal (matrix)-facing NAD(P)H dehydrogenases (CaNDA1-4 and CaNDC1) and four putative external (inter-membrane space)-facing NAD(P)H dehydrogenases (CaNDB1-4) were identified in chickpea. The corresponding activities were demonstrated for the first time in purified mitochondria of chickpea leaves and roots. Oxidation of matrix NADH generated from malate or glycine in the presence of the Complex I inhibitor rotenone was high compared to other plant species, as was oxidation of exogenous NAD(P)H. In leaf mitochondria, external NADH oxidation was stimulated by exogenous calcium and external NADPH oxidation was essentially calcium dependent. However, in roots these activities were low and largely calcium independent. A salinity experiment with six chickpea cultivars was used to identify salt-responsive alternative oxidase and NAD(P)H dehydrogenase gene transcripts in leaves from a three-point time series. An analysis of the Na:K ratio and Na content separated these cultivars into high and low Na accumulators. In the high Na accumulators, there was a significant up-regulation of CaAOX1, CaNDB2, CaNDB4, CaNDA3 and CaNDC1 in leaf tissue under long term stress, suggesting the formation of a stress-modified form of the mitochondrial electron transport chain (mETC) in leaves of these cultivars. In particular, stress-induced expression of the CaNDB2 gene showed a striking positive correlation with that of CaAOX1 across all genotypes and time points. The coordinated salinity-induced up-regulation of CaAOX1 and CaNDB2 suggests that the mitochondrial alternative pathway of respiration is an important facet of the stress response in chickpea, in high Na accumulators in particular, despite high capacities for both of these activities in leaf mitochondria of non-stressed chickpeas.
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Affiliation(s)
- Crystal Sweetman
- College of Science & Engineering, Flinders University, GPO Box 5100, Adelaide SA 5001, Australia; (T.K.M.); (N.J.B.); (Y.S.); (C.L.D.J.); (K.L.S.); (D.A.D.)
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Vanlerberghe GC, Dahal K, Alber NA, Chadee A. Photosynthesis, respiration and growth: A carbon and energy balancing act for alternative oxidase. Mitochondrion 2020; 52:197-211. [PMID: 32278748 DOI: 10.1016/j.mito.2020.04.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/28/2020] [Accepted: 04/06/2020] [Indexed: 12/26/2022]
Abstract
This review summarizes knowledge of alternative oxidase, a mitochondrial electron transport chain component that lowers the ATP yield of plant respiration. Analysis of mutant and transgenic plants has established that alternative oxidase activity supports leaf photosynthesis. The interaction of alternative oxidase respiration with chloroplast metabolism is important under conditions that challenge energy and/or carbon balance in the photosynthetic cell. Under such conditions, alternative oxidase provides an extra-chloroplastic means to optimize the status of chloroplast energy pools (ATP, NADPH) and to manage cellular carbohydrate pools in response to changing rates of carbon fixation and carbon demand for growth and maintenance. Transcriptional and post-translational mechanisms ensure that alternative oxidase can respond effectively when carbon and energy balance are being challenged. This function appears particularly significant under abiotic stress conditions such as water deficit, high salinity, or temperature extremes. Under such conditions, alternative oxidase respiration positively affects growth and stress tolerance, despite it lowering the energy yield and carbon use efficiency of respiration. In part, this beneficial effect relates to the ability of alternative oxidase respiration to prevent excessive reactive oxygen species generation in both mitochondria and chloroplasts. Recent evidence suggests that alternative oxidase respiration is an interesting target for crop improvement.
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Affiliation(s)
- Greg C Vanlerberghe
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C1A4, Canada.
| | - Keshav Dahal
- Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, 850 Lincoln Road, P.O. Box 20280, Fredericton, New Brunswick E3B4Z7, Canada
| | - Nicole A Alber
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C1A4, Canada
| | - Avesh Chadee
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C1A4, Canada
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Yamada S, Ozaki H, Noguchi K. The Mitochondrial Respiratory Chain Maintains the Photosynthetic Electron Flow in Arabidopsis thaliana Leaves under High-Light Stress. PLANT & CELL PHYSIOLOGY 2020; 61:283-295. [PMID: 31603217 DOI: 10.1093/pcp/pcz193] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 10/07/2019] [Indexed: 05/02/2023]
Abstract
The plant respiratory chain includes the ATP-coupling cytochrome pathway (CP) and ATP-uncoupling alternative oxidase (AOX). Under high-light (HL) conditions, plants experience photoinhibition, leading to a damaged photosystem II (PSII). The respiratory chain is considered to affect PSII maintenance and photosynthetic electron transport under HL conditions. However, the underlying details remain unclear. In this study, we investigated the respiratory chain functions related to PSII maintenance and photosynthetic electron transport in plants exposed to HL stress. We measured the HL-induced decrease in the maximum quantum yield of PSII in the leaves of wild-type and AOX1a-knockout (aox1a) Arabidopsis thaliana plants in which CP was partially inhibited by a complex-III inhibitor. We also calculated PSII photodamage and repair rate constants. Both rate constants changed when CP was partially inhibited in aox1a plants, suggesting that the respiratory chain is related to both processes. Before HL stress, photosynthetic linear electron flow (LEF) decreased when CP was partially inhibited. After HL stress, aox1a in the presence of the CP inhibitor showed significantly decreased rates of LEF. The electron flow downstream from PSII and on the donor side of photosystem I may have been suppressed. The function of respiratory chain is required to maintain the optimal LEF as well as PSII maintenance especially under the HL stress.
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Affiliation(s)
- Shoya Yamada
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392 Japan
| | - Hiroshi Ozaki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392 Japan
| | - Ko Noguchi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392 Japan
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Vanlerberghe GC, Dahal K, Chadee A. Does the stromal concentration of P i control chloroplast ATP synthase protein amount in contrasting growth environments? PLANT SIGNALING & BEHAVIOR 2019; 14:1675473. [PMID: 31583956 PMCID: PMC6866698 DOI: 10.1080/15592324.2019.1675473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 05/16/2023]
Abstract
Changes in the growth environment can generate imbalances in chloroplast photosynthetic metabolism. Under water deficit, stomatal closure limits CO2 availability such that the production of ATP and NADPH by the thylakoid membrane-localized electron transport chain may not match the consumption of these energy intermediates by the stroma-localized Calvin-Benson cycle, thus challenging energy balance. Alternatively, in an elevated CO2 atmosphere, carbon fixation by the Calvin-Benson cycle may outpace the activity of downstream carbohydrate-utilizing processes, thus challenging carbon balance. Our previous studies have shown that, in both of the above scenarios, a mitochondrial alternative oxidase contributes to maintaining energy or carbon balance, highlighting the importance of photosynthesis-respiration interactions in optimizing photosynthesis in different growth environments. In these previous studies, we observed aberrant amounts of chloroplast ATP synthase protein across the different transgenic plant lines and growth conditions, compared to wild-type. Based on these observations, we develop here the hypothesis that an important determinant of chloroplast ATP synthase protein amount is the stromal concentration of inorganic phosphate. ATP synthase is a master regulator of photosynthesis. Coarse control of ATP synthase protein amount by the stromal inorganic phosphate status could provide a means to coordinate the electron transport and carbon fixation reactions of photosynthesis.
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Affiliation(s)
- Greg C. Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Keshav Dahal
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Avesh Chadee
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
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Dahal K, Li XQ, Tai H, Creelman A, Bizimungu B. Improving Potato Stress Tolerance and Tuber Yield Under a Climate Change Scenario - A Current Overview. FRONTIERS IN PLANT SCIENCE 2019; 10:563. [PMID: 31139199 PMCID: PMC6527881 DOI: 10.3389/fpls.2019.00563] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 04/12/2019] [Indexed: 05/06/2023]
Abstract
Global climate change in the form of extreme heat and drought poses a major challenge to sustainable crop production by negatively affecting plant performance and crop yield. Such negative impact on crop yield is likely to be aggravated in future because continued greenhouse gas emissions will cause further rise in temperature leading to increased evapo-transpiration and drought severity, soil salinity as well as insect and disease threats. This has raised a major challenge for plant scientists on securing global food demand, which urges an immediate need to enhance the current yield of major food crops by two-fold to feed the increasing population. As a fourth major food crop, enhancing potato productivity is important for food security of an increasing population. However, potato plant is highly prone to high temperature, drought, soil salinity, as well as insect and diseases. In order to maintain a sustainable potato production, we must adapt our cultivation practices and develop stress tolerant potato cultivars that are appropriately engineered for changing environment. Yet the lack of data on the underlying mechanisms of potato plant resistance to abiotic and biotic stress and the ability to predict future outcomes constitutes a major knowledge gap. It is a challenge for plant scientists to pinpoint means of improving tuber yield under increasing CO2, high temperature and drought stress including the changing patterns of pest and pathogen infestations. Understanding stress-related physiological, biochemical and molecular processes is crucial to develop screening procedures for selecting crop cultivars that can better adapt to changing growth conditions. Elucidation of such mechanism may offer new insights into the identification of specific characteristics that may be useful in breeding new cultivars aimed at maintaining or even enhancing potato yield under changing climate. This paper discusses the recent progress on the mechanism by which potato plants initially sense the changes in their surrounding CO2, temperature, water status, soil salinity and consequently respond to these changes at the molecular, biochemical and physiological levels. We suggest that future research needs to be concentrated on the identification and characterization of signaling molecules and target genes regulating stress tolerance and crop yield potential.
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Affiliation(s)
- Keshav Dahal
- Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, Fredericton, NB, Canada
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McClain AM, Sharkey TD. Triose phosphate utilization and beyond: from photosynthesis to end product synthesis. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1755-1766. [PMID: 30868155 PMCID: PMC6939825 DOI: 10.1093/jxb/erz058] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 03/07/2019] [Indexed: 05/18/2023]
Abstract
During photosynthesis, plants fix CO2 from the atmosphere onto ribulose-bisphosphate, producing 3-phosphoglycerate, which is reduced to triose phosphates (TPs). The TPs are then converted into the end products of photosynthesis. When a plant is photosynthesizing very quickly, it may not be possible to commit photosynthate to end products as fast as it is produced, causing a decrease in available phosphate and limiting the rate of photosynthesis to the rate of triose phosphate utilization (TPU). The occurrence of an observable TPU limitation is highly variable based on species and especially growth conditions, with TPU capacity seemingly regulated to be in slight excess of typical photosynthetic rates the plant might experience. The physiological effects of TPU limitation are discussed with an emphasis on interactions between the Calvin-Benson cycle and the light reactions. Methods for detecting TPU-limited data from gas exchange data are detailed and the impact on modeling of some physiological effects are shown. Special consideration is given to common misconceptions about TPU.
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Affiliation(s)
- Alan M McClain
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, East Lansing, MI, USA
- Plant Biotechnology for Health and Sustainability Program, East Lansing, MI, USA
| | - Thomas D Sharkey
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, East Lansing, MI, USA
- Plant Biotechnology for Health and Sustainability Program, East Lansing, MI, USA
- Plant Resilience Institute, Plant Biology Laboratories, East Lansing, MI, USA
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Sunil B, Saini D, Bapatla RB, Aswani V, Raghavendra AS. Photorespiration is complemented by cyclic electron flow and the alternative oxidase pathway to optimize photosynthesis and protect against abiotic stress. PHOTOSYNTHESIS RESEARCH 2019; 139:67-79. [PMID: 30187303 DOI: 10.1007/s11120-018-0577-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/24/2018] [Indexed: 05/02/2023]
Abstract
Optimization of photosynthetic performance and protection against abiotic stress are essential to sustain plant growth. Photorespiratory metabolism can help plants to adapt to abiotic stress. The beneficial role of photorespiration under abiotic stress is further strengthened by cyclic electron flow (CEF) and alternative oxidase (AOX) pathways. We have attempted to critically assess the literature on the responses of these three phenomena-photorespiration, CEF and AOX, to different stress situations. We emphasize that photorespiration is the key player to protect photosynthesis and upregulates CEF as well as AOX. Then these three processes work in coordination to protect the plants against photoinhibition and maintain an optimal redox state in the cell, while providing ATP for metabolism and protein repair. H2O2 generated during photorespiratory metabolism seems to be an important signal to upregulate CEF or AOX. Further experiments are necessary to identify the signals originating from CEF or AOX to modulate photorespiration. The mutants deficient in CEF or AOX or both could be useful in this regard. The mutual interactions between CEF and AOX, so as to keep their complementarity, are also to be examined further.
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Affiliation(s)
- Bobba Sunil
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Deepak Saini
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Ramesh B Bapatla
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Vetcha Aswani
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Agepati S Raghavendra
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India.
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23
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Sweetman C, Soole KL, Jenkins CLD, Day DA. Genomic structure and expression of alternative oxidase genes in legumes. PLANT, CELL & ENVIRONMENT 2019; 42:71-84. [PMID: 29424926 DOI: 10.1111/pce.13161] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/22/2018] [Accepted: 01/25/2018] [Indexed: 05/26/2023]
Abstract
Mitochondria isolated from chickpea (Cicer arietinum) possess substantial alternative oxidase (AOX) activity, even in non-stressed plants, and one or two AOX protein bands were detected immunologically, depending on the organ. Four different AOX isoforms were identified in the chickpea genome: CaAOX1 and CaAOX2A, B and D. CaAOX2A was the most highly expressed form and was strongly expressed in photosynthetic tissues, whereas CaAOX2D was found in all organs examined. These results are very similar to those of previous studies with soybean and siratro. Searches of available databases showed that this pattern of AOX genes and their expression was common to at least 16 different legume species. The evolution of the legume AOX gene family is discussed, as is the in vivo impact of an inherently high AOX capacity in legumes on growth and responses to environmental stresses.
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Affiliation(s)
- Crystal Sweetman
- Australian Research Council Industrial Transformation Research Hub, Legumes for Sustainable Agriculture, College of Science and Engineering, Flinders University of South Australia, Adelaide, South Australia, GPO Box 2001, Australia
| | - Kathleen L Soole
- Australian Research Council Industrial Transformation Research Hub, Legumes for Sustainable Agriculture, College of Science and Engineering, Flinders University of South Australia, Adelaide, South Australia, GPO Box 2001, Australia
| | - Colin L D Jenkins
- Australian Research Council Industrial Transformation Research Hub, Legumes for Sustainable Agriculture, College of Science and Engineering, Flinders University of South Australia, Adelaide, South Australia, GPO Box 2001, Australia
| | - David A Day
- Australian Research Council Industrial Transformation Research Hub, Legumes for Sustainable Agriculture, College of Science and Engineering, Flinders University of South Australia, Adelaide, South Australia, GPO Box 2001, Australia
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24
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Kaye Y, Huang W, Clowez S, Saroussi S, Idoine A, Sanz-Luque E, Grossman AR. The mitochondrial alternative oxidase from Chlamydomonas reinhardtii enables survival in high light. J Biol Chem 2018; 294:1380-1395. [PMID: 30510139 DOI: 10.1074/jbc.ra118.004667] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/24/2018] [Indexed: 01/07/2023] Open
Abstract
Photosynthetic organisms often experience extreme light conditions that can cause hyper-reduction of the chloroplast electron transport chain, resulting in oxidative damage. Accumulating evidence suggests that mitochondrial respiration and chloroplast photosynthesis are coupled when cells are absorbing high levels of excitation energy. This coupling helps protect the cells from hyper-reduction of photosynthetic electron carriers and diminishes the production of reactive oxygen species (ROS). To examine this cooperative protection, here we characterized Chlamydomonas reinhardtii mutants lacking the mitochondrial alternative terminal respiratory oxidases, CrAOX1 and CrAOX2. Using fluorescent fusion proteins, we experimentally demonstrated that both enzymes localize to mitochondria. We also observed that the mutant strains were more sensitive than WT cells to high light under mixotrophic and photoautotrophic conditions, with the aox1 strain being more sensitive than aox2 Additionally, the lack of CrAOX1 increased ROS accumulation, especially in very high light, and damaged the photosynthetic machinery, ultimately resulting in cell death. These findings indicate that the Chlamydomonas AOX proteins can participate in acclimation of C. reinhardtii cells to excess absorbed light energy. They suggest that when photosynthetic electron carriers are highly reduced, a chloroplast-mitochondria coupling allows safe dissipation of photosynthetically derived electrons via the reduction of O2 through AOX (especially AOX1)-dependent mitochondrial respiration.
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Affiliation(s)
- Yuval Kaye
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305.
| | - Weichao Huang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Sophie Clowez
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Shai Saroussi
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Adam Idoine
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Emanuel Sanz-Luque
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
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25
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Locato V, Cimini S, De Gara L. ROS and redox balance as multifaceted players of cross-tolerance: epigenetic and retrograde control of gene expression. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:3373-3391. [PMID: 29722828 DOI: 10.1093/jxb/ery168] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 04/27/2018] [Indexed: 05/07/2023]
Abstract
Retrograde pathways occurring between chloroplasts, mitochondria, and the nucleus involve oxidative and antioxidative signals that, working in a synergistic or antagonistic mode, control the expression of specific patterns of genes following stress perception. Increasing evidence also underlines the relevance of mitochondrion-chloroplast-nucleus crosstalk in modulating the whole cellular redox metabolism by a controlled and integrated flux of information. Plants can maintain the acquired tolerance by a stress memory, also operating at the transgenerational level, via epigenetic and miRNA-based mechanisms controlling gene expression. Data discussed in this review strengthen the idea that ROS, redox signals, and shifts in cellular redox balance permeate the signalling network leading to cross-tolerance. The identification of specific ROS/antioxidative signatures leading a plant to different fates under stress is pivotal for identifying strategies to monitor and increase plant fitness in a changing environment. This review provides an update of the plant redox signalling network implicated in stress responses, in particular in cross-tolerance acquisition. The interplay between reactive oxygen species (ROS), ROS-derived signals, and antioxidative pathways is also discussed in terms of plant acclimation to stress in the short and long term.
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Affiliation(s)
- Vittoria Locato
- Unit of Food Science and Human Nutrition, Campus Bio-Medico University, Rome, Italy
| | - Sara Cimini
- Unit of Food Science and Human Nutrition, Campus Bio-Medico University, Rome, Italy
| | - Laura De Gara
- Unit of Food Science and Human Nutrition, Campus Bio-Medico University, Rome, Italy
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26
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Dahal K, Vanlerberghe GC. Improved chloroplast energy balance during water deficit enhances plant growth: more crop per drop. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:1183-1197. [PMID: 29281082 PMCID: PMC6018952 DOI: 10.1093/jxb/erx474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 12/07/2017] [Indexed: 05/02/2023]
Abstract
The non-energy-conserving alternative oxidase (AOX) respiration of plant mitochondria is known to interact with chloroplast photosynthesis. This may have consequences for growth, particularly under sub-optimal conditions when energy imbalances can impede photosynthesis. This hypothesis was tested by comparing the metabolism and growth of wild-type Nicotiana tabacum with that of AOX knockdown and overexpression lines during a prolonged steady-state mild to moderate water deficit. Under moderate water deficit, the AOX amount was an important determinant of the rate of both mitochondrial respiration in the light and net photosynthetic CO2 assimilation (A) at the growth irradiance. In particular, AOX respiration was necessary to maintain optimal proton and electron fluxes at the chloroplast thylakoid membrane, which in turn prevented a water-deficit-induced biochemical limitation of photosynthesis. As a result of differences in A, AOX overexpressors gained more biomass and knockdowns gained less biomass than wild-type during moderate water deficit. Biomass partitioning also differed, with the overexpressors having a higher percentage, and the knockdowns having a lower percentage, of total above-ground biomass in reproductive tissue than wild-type. The results establish that improving chloroplast energy balance by using a non-energy-conserving respiratory electron sink can increase photosynthesis and growth during prolonged water deficit.
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Affiliation(s)
- Keshav Dahal
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Greg C Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, Ontario, Canada
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27
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Barreto P, Yassitepe JECT, Wilson ZA, Arruda P. Mitochondrial Uncoupling Protein 1 Overexpression Increases Yield in Nicotiana tabacum under Drought Stress by Improving Source and Sink Metabolism. FRONTIERS IN PLANT SCIENCE 2017; 8:1836. [PMID: 29163573 PMCID: PMC5672497 DOI: 10.3389/fpls.2017.01836] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 10/10/2017] [Indexed: 05/18/2023]
Abstract
Mitochondrial uncoupling proteins (UCPs) sustain mitochondrial respiration independent of intracellular ATP concentration. Uncoupled respiration is particularly beneficial under stress conditions, during which both photosynthesis and respiration may be impaired. Sustaining carbon fixation during the reproductive phase is essential for plants to develop viable pollen grains and for seed setting. Here, we examined whether UCP1 overexpression (UCP1-oe) would help tobacco plants cope with drought stress during reproductive development. We observed that WT and UCP1-oe plants lost water at the same rate under moderate drought stress, but that UCP1-oe lines regained water faster upon rewatering. UCP1-oe plants maintained higher levels of respiration and photosynthesis and decreased H2O2 content in the leaves during the drought stress period. We examined whether UCP1-oe impacts reproductive tissues and seed production by monitoring the progress of flower development, focusing on the early stages of pollen formation. UCP1-oe lines induced the expression of mitochondrial genes and increased mtDNA content in reproductive tissues, which increased the consumption of carbohydrates and reduced H2O2 content and pollen disturbances. Finally, the beneficial impact of UCP1-oe on the source and sink organs resulted in an increased seed size and number under both control conditions and drought stress.
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Affiliation(s)
- Pedro Barreto
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, Brazil
- Joint Research Center for Genomics Applied to Climate Change (UMIP GenClima), Campinas, Brazil
| | - Juliana E. C. T. Yassitepe
- Joint Research Center for Genomics Applied to Climate Change (UMIP GenClima), Campinas, Brazil
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Informática Agropecuária, Campinas, Brazil
| | - Zoe A. Wilson
- School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Paulo Arruda
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, Brazil
- Joint Research Center for Genomics Applied to Climate Change (UMIP GenClima), Campinas, Brazil
- Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
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28
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Xie XL, Xia XJ, Kuang S, Zhang XL, Yin XR, Yu JQ, Chen KS. A novel ethylene responsive factor CitERF13 plays a role in photosynthesis regulation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2017; 256:112-119. [PMID: 28167024 DOI: 10.1016/j.plantsci.2016.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 11/01/2016] [Accepted: 11/03/2016] [Indexed: 05/22/2023]
Abstract
Ethylene responsive factors (ERFs) act as critical downstream components of the ethylene signalling pathway in regulating plant development and stress responses. However little is known about its role in regulation of photosynthesis. Here, we identified an ethylene-inducible ERF gene in citrus, CitERF13. Transient over-expression of CitERF13 in N. tabacum leaves, resulted in a significant decrease in net photosynthetic rate. Closer examination of photosynthetic activity of PSII and PSI indicated that CitERF13 overexpression led to declines of Fv/Fm, Y(II) and Y(I). However, change in NPQ was less pronounced. CitERF13 overexpression also significantly reduced Vc,max, Jmax and AQY, indicating inhibition of the Calvin cycle. The expression of photosynthesis-related genes was suppressed to a variable extent in leaf blades transiently over-expressing CitERF13. CitERF13 transient overexpression in tobacco or citrus both resulted in a decline of Chlorophyll content and CitERF13 overexpressing tobacco leaf disc was more susceptible to chlorosis in response to MV-mediated oxidative stress. The results suggest that CitERF13 is potentially involved in suppressing photosynthesis through multiple pathways, for instance, inhibiting photochemical activity of photosynthesis, CO2 carboxylation capacity and chlorophyll metabolism.
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Affiliation(s)
- Xiu-Lan Xie
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China; The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China
| | - Xiao-Jian Xia
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China; The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China
| | - Sheng Kuang
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China
| | - Xi-Li Zhang
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China
| | - Xue-Ren Yin
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China; The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China
| | - Jing-Quan Yu
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China; The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China
| | - Kun-Song Chen
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China; The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058, PR China.
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29
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Zhang ZS, Liu MJ, Scheibe R, Selinski J, Zhang LT, Yang C, Meng XL, Gao HY. Contribution of the Alternative Respiratory Pathway to PSII Photoprotection in C3 and C4 Plants. MOLECULAR PLANT 2017; 10:131-142. [PMID: 27746301 DOI: 10.1016/j.molp.2016.10.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 09/29/2016] [Accepted: 10/05/2016] [Indexed: 05/02/2023]
Abstract
The mechanism by which the mitochondrial alternative oxidase (AOX) pathway contributes to photosystem II (PSII) photoprotection is in dispute. It was generally thought that the AOX pathway protects photosystems by dissipating excess reducing equivalents exported from chloroplasts through the malate/oxaloacetate (Mal/OAA) shuttle and thus preventing the over-reduction of chloroplasts. In this study, using the aox1a Arabidopsis mutant and nine other C3 and C4 plant species, we revealed an additional action model of the AOX pathway in PSII photoprotection. Although the AOX pathway contributes to PSII photoprotection in C3 leaves treated with high light, this contribution was observed to disappear when photorespiration was suppressed. Disruption or inhibition of the AOX pathway significantly decreased the photorespiration in C3 leaves. Moreover, the AOX pathway did not respond to high light and contributed little to PSII photoprotection in C4 leaves possessing a highly active Mal/OAA shuttle but with little photorespiration. These results demonstrate that the AOX pathway contributes to PSII photoprotection in C3 plants by maintaining photorespiration to detoxify glycolate and via the indirect export of excess reducing equivalents from chloroplasts by the Mal/OAA shuttle. This new action model explains why the AOX pathway does not contribute to PSII photoprotection in C4 plants.
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Affiliation(s)
- Zi-Shan Zhang
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an 271018, China; College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China
| | - Mei-Jun Liu
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an 271018, China; College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Renate Scheibe
- Department of Plant Physiology, FB5, University of Osnabrueck, 49069 Osnabrueck, Germany
| | - Jennifer Selinski
- Department of Plant Physiology, FB5, University of Osnabrueck, 49069 Osnabrueck, Germany
| | - Li-Tao Zhang
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an 271018, China; College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China; National and Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China
| | - Cheng Yang
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an 271018, China; College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China; Wheat Research Institute, Henan Academy of Agricultural Sciences, Zhengzhou, Henan 450002, China
| | - Xiang-Long Meng
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an 271018, China; College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Hui-Yuan Gao
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an 271018, China; College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China.
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30
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Dahal K, Vanlerberghe GC. Alternative oxidase respiration maintains both mitochondrial and chloroplast function during drought. THE NEW PHYTOLOGIST 2017; 213:560-571. [PMID: 27579773 DOI: 10.1111/nph.14169] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 07/29/2016] [Indexed: 05/19/2023]
Abstract
The mitochondrial electron transport chain (ETC) terminates at cytochrome (cyt) oxidase or alternative oxidase (AOX). In Nicotiana tabacum leaves, mitochondrial respiration in the light (RL ) declined with increasing drought severity but then increased under extreme drought, despite a steep decline in maximal cyt oxidase activity. This increased RL was absent in AOX knockdown lines, while AOX overexpression lines showed enhanced RL relative to the wild-type (WT). Cyt oxidase activity under extreme drought was higher in overexpressors and lower in knockdowns, compared with the WT, providing evidence that AOX acted to maintain cyt pathway function. The rate of RL was a strong determinant of the reduction state of the photosynthetic ETC during drought. As such, the maximal quantum yield of photosystem II was compromised in knockdowns, compared with the WT, during extreme drought. By contrast, overexpressors maintained their instantaneous leaf water-use efficiency equally as high during extreme drought as when they were well watered. In both mitochondria and chloroplasts, protein carbonyl accumulation during extreme drought was strongly increased in knockdowns, and decreased in overexpressors, relative to WT. Hence the ability of AOX to maintain critical mitochondrial and chloroplast functions during extreme drought is likely due, at least in part, to its ability to reduce oxidative damage.
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Affiliation(s)
- Keshav Dahal
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C1A4, Canada
| | - Greg C Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C1A4, Canada
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31
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Dahal K, Martyn GD, Alber NA, Vanlerberghe GC. Coordinated regulation of photosynthetic and respiratory components is necessary to maintain chloroplast energy balance in varied growth conditions. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:657-671. [PMID: 28011719 PMCID: PMC5441918 DOI: 10.1093/jxb/erw469] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Mitochondria have a non-energy-conserving alternative oxidase (AOX) proposed to support photosynthesis, perhaps by promoting energy balance under varying growth conditions. To investigate this, wild-type (WT) Nicotiana tabacum were compared with AOX knockdown and overexpression lines. In addition, the amount of AOX protein in WT plants was compared with that of chloroplast light-harvesting complex II (LHCB2), whose amount is known to respond to chloroplast energy status. With increased growth irradiance, WT leaves maintained higher rates of respiration in the light (RL), but no differences in RL or photosynthesis were seen between the WT and transgenic lines, suggesting that, under non-stress conditions, AOX was not critical for leaf metabolism, regardless of growth irradiance. However, under drought, the AOX amount became an important determinant of RL, which in turn was an important determinant of chloroplast energy balance (measured as photosystem II excitation pressure, EP), and photosynthetic performance. In the WT, the AOX amount increased and the LHCB2 amount decreased with increased growth irradiance or drought severity. These changes in protein amounts correlated strongly, in opposing ways, with growth EP. This suggests that a signal deriving from the photosynthetic electron transport chain status coordinately controls the amounts of AOX and LHCB2, which then both contribute to maintaining chloroplast energy balance, particularly under stress conditions.
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Affiliation(s)
- Keshav Dahal
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Military Trail, Toronto,
ON, Canada
| | - Greg D Martyn
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Military Trail, Toronto,
ON, Canada
| | - Nicole A Alber
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Military Trail, Toronto,
ON, Canada
| | - Greg C Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Military Trail, Toronto,
ON, Canada
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32
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Florez-Sarasa I, Ribas-Carbo M, Del-Saz NF, Schwahn K, Nikoloski Z, Fernie AR, Flexas J. Unravelling the in vivo regulation and metabolic role of the alternative oxidase pathway in C3 species under photoinhibitory conditions. THE NEW PHYTOLOGIST 2016; 212:66-79. [PMID: 27321208 DOI: 10.1111/nph.14030] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 04/23/2016] [Indexed: 06/06/2023]
Abstract
The mitochondrial alternative oxidase pathway (AOP) has been suggested to act as a sink for excess reducing power generated in the chloroplast under high-light (HL) stress and thus may reduce photoinhibition. The aim of this study was to compare different species to investigate the in vivo regulation and role of AOP under HL stress. The in vivo activities of AOP (νalt ) and the cytochrome oxidase pathway, chlorophyll fluorescence, metabolite profiles, alternative oxidase (AOX) capacity and protein amount were determined in leaves of five C3 species under growth light and after HL treatment. Differences in respiration and metabolite levels were observed among species under growth light conditions. The HL response of νalt was highly species dependent, correlated with the AOP capacity and independent of AOX protein content. Nevertheless, significant correlations were observed between νalt , levels of key metabolites and photosynthetic parameters. The results show that the species-specific response of νalt is caused by the differential post-translational regulation of AOX. Significant correlations between respiration, metabolites and photosynthetic performance across species suggest that AOP may permit stress-related amino acid synthesis, whilst maintaining photosynthetic activity under HL stress.
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Affiliation(s)
- Igor Florez-Sarasa
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Miquel Ribas-Carbo
- Grup de Recerca en Biologia de les Plantes en Condicions Mediterranies, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Spain
| | - Néstor Fernández Del-Saz
- Grup de Recerca en Biologia de les Plantes en Condicions Mediterranies, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Spain
| | - Kevin Schwahn
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Zoran Nikoloski
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Jaume Flexas
- Grup de Recerca en Biologia de les Plantes en Condicions Mediterranies, Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Spain
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33
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Watanabe CKA, Yamori W, Takahashi S, Terashima I, Noguchi K. Mitochondrial Alternative Pathway-Associated Photoprotection of Photosystem II is Related to the Photorespiratory Pathway. PLANT & CELL PHYSIOLOGY 2016; 57:1426-1431. [PMID: 26903530 DOI: 10.1093/pcp/pcw036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 02/10/2016] [Indexed: 05/21/2023]
Abstract
Respiratory electron transport has two ubiquinol-oxidizing pathways, the cytochrome pathway (CP) and the alternative pathway (AP). The AP, which is catalyzed by the alternative oxidase (AOX), is energetically wasteful but may alleviate PSII photoinhibition under light conditions excessive for photosynthesis. However, its mechanism remains unknown. We used Arabidopsis aox1a mutants lacking AOX activity and studied the mutation's effects on photoinhibition by measuring the decrease in the maximum quantum yield of PSII (Fv/Fm) after high light exposure. Since the CP compensates for the lack of AOX, we monitored the extent of photoinhibition under conditions where CP activity is partially inhibited by antimycin A. When leaves were exposed to high light at 350 µmol m-2 s-1, the decline in Fv/Fm was significantly faster in the aox1a mutants than in the wild type. However, under conditions where photorespiration was suppressed by high CO2 or low O2 levels, the decline in Fv/Fm was suppressed in the aox1a mutants, but not in the wild type, making the difference between the wild type and mutants small. Our results demonstrate that the lack of the AP causes an acceleration of PSII photoinhibition in relation to the photorespiratory pathway, suggesting that the AP can support the activity of the photorespiratory pathway under high light conditions.
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Affiliation(s)
- Chihiro K A Watanabe
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Wataru Yamori
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
- Center for Environment, Health and Field Sciences, Chiba University, Kashiwa, Chiba, 277-0882 Japan
| | - Shunichi Takahashi
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, 2601 Australia
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, 444-8585 Japan
| | - Ichiro Terashima
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Ko Noguchi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392 Japan
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Vanlerberghe GC, Martyn GD, Dahal K. Alternative oxidase: a respiratory electron transport chain pathway essential for maintaining photosynthetic performance during drought stress. PHYSIOLOGIA PLANTARUM 2016; 157:322-37. [PMID: 27080742 DOI: 10.1111/ppl.12451] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 03/11/2016] [Indexed: 05/19/2023]
Abstract
Photosynthesis and respiration are the hubs of energy metabolism in plants. Drought strongly perturbs photosynthesis as a result of both diffusive limitations resulting from stomatal closure, and in some cases biochemical limitations that are associated with a reduced abundance of key photosynthetic components. The effects of drought on respiration, particularly respiration in the light (RL ), are less understood. The plant mitochondrial electron transport chain includes a non-energy conserving terminal oxidase called alternative oxidase (AOX). Several studies have shown that drought increases AOX transcript, protein and maximum capacity. Here we review recent studies comparing wild-type (WT) tobacco to transgenic lines with altered AOX protein amount. Specifically during drought, RL was compromised in AOX knockdown plants and enhanced in AOX overexpression plants, compared with WT. Significantly, these differences in RL were accompanied by dramatic differences in photosynthetic performance. Knockdown of AOX increased the susceptibility of photosynthesis to drought-induced biochemical limitations, while overexpression of AOX delayed the development of such biochemical limitations, compared with WT. Overall, the results indicate that AOX is essential to maintaining RL during drought, and that this non-energy conserving respiration maintains photosynthesis during drought by promoting energy balance in the chloroplast. This review also outlines several areas for future research, including the possibility that enhancement of non-energy conserving respiratory electron sinks may be a useful biotechnological approach to increase plant performance during stress.
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Affiliation(s)
- Greg C Vanlerberghe
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, M1C1A4, Canada
- Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, M1C1A4, Canada
| | - Greg D Martyn
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, M1C1A4, Canada
- Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, M1C1A4, Canada
| | - Keshav Dahal
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, M1C1A4, Canada
- Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, M1C1A4, Canada
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Fromm S, Braun HP, Peterhansel C. Mitochondrial gamma carbonic anhydrases are required for complex I assembly and plant reproductive development. THE NEW PHYTOLOGIST 2016; 211:194-207. [PMID: 26889912 DOI: 10.1111/nph.13886] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 01/04/2016] [Indexed: 05/23/2023]
Abstract
Complex I of the mitochondrial electron transport chain (mETC) in plants contains an extra domain that is made up from proteins homologous to prokaryotic gamma-carbonic anhydrases (γCA). This domain has been suggested to participate in complex I assembly or to support transport of mitochondrial CO2 to the chloroplast. Here, we generated mutants lacking CA1 and CA2 - two out of three CA proteins in Arabidopsis thaliana. Double mutants were characterized at the developmental and physiological levels. Furthermore, the composition and activity of the mETC were determined, and mutated CA versions were used for complementation assays. Embryo development of double mutants was strongly delayed and seed development stopped before maturation. Mutant plants could only be rescued on sucrose media, showed severe stress symptoms and never produced viable seeds. By contrast, callus cultures were only slightly affected in growth. Complex I was undetectable in the double mutants, but complex II and complex IV were upregulated concomitant with increased oxygen consumption in mitochondrial respiration. Ectopic expression of inactive CA variants was sufficient to complement the mutant phenotype. Data indicate that CA proteins are structurally required for complex I assembly and that reproductive development is dependent on the presence of complex I.
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Affiliation(s)
- Steffanie Fromm
- Institute of Plant Genetics, Leibniz Universität Hannover, 30419, Hannover, Germany
- Institute of Botany, Leibniz Universität Hannover, 30419, Hannover, Germany
| | - Hans-Peter Braun
- Institute of Plant Genetics, Leibniz Universität Hannover, 30419, Hannover, Germany
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Yang JT, Preiser AL, Li Z, Weise SE, Sharkey TD. Triose phosphate use limitation of photosynthesis: short-term and long-term effects. PLANTA 2016; 243:687-98. [PMID: 26620947 DOI: 10.1007/s00425-015-2436-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 11/16/2015] [Indexed: 05/02/2023]
Abstract
MAIN CONCLUSION The triose phosphate use limitation was studied using long-term and short term changes in capacity. The TPU limitation caused increased proton motive force; long-term TPU limitation additionally reduced other photosynthetic components. Photosynthetic responses to CO2 can be interpreted primarily as being limited by the amount or activity of Rubisco or the capacity for ribulose bisphosphate regeneration, but at high rates of photosynthesis a third response is often seen. Photosynthesis becomes insensitive to CO2 or even declines with increasing CO2, and this behavior has been associated with a limitation of export of carbon from the Calvin-Benson cycle. It is often called the triose phosphate use (TPU) limitation. We studied the long-term consequences of this limitation using plants engineered to have reduced capacity for starch or sucrose synthesis. We studied short-term consequences using temperature as a method for changing the balance of carbon fixation capacity and TPU. A long-term and short-term TPU limitation resulted in an increase in proton motive force (PMF) in the thylakoids. Once a TPU limitation was reached, any further increases in CO2 was met with a further increase in the PMF but no increase or little increase in net assimilation of CO2. A long-term TPU limitation resulted in reduced Rubisco and RuBP regeneration capacity. We hypothesize that TPU, Rubisco activity, and RuBP regeneration are regulated so that TPU is normally in slight excess of what is required, and that this results in more effective regulation than if TPU were in large excess.
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Affiliation(s)
- Jennifer T Yang
- Department of Biochemistry and Molecular Biology, Michigan State University, 201 Biochemistry, 603 Wilson Rd, East Lansing, MI, 48824, USA
- Intercollege Program of Plant Biology, The Pennsylvania State University, State College, PA, 16802, USA
| | - Alyssa L Preiser
- Department of Biochemistry and Molecular Biology, Michigan State University, 201 Biochemistry, 603 Wilson Rd, East Lansing, MI, 48824, USA
| | - Ziru Li
- Department of Biochemistry and Molecular Biology, Michigan State University, 201 Biochemistry, 603 Wilson Rd, East Lansing, MI, 48824, USA
| | - Sean E Weise
- Department of Biochemistry and Molecular Biology, Michigan State University, 201 Biochemistry, 603 Wilson Rd, East Lansing, MI, 48824, USA
| | - Thomas D Sharkey
- Department of Biochemistry and Molecular Biology, Michigan State University, 201 Biochemistry, 603 Wilson Rd, East Lansing, MI, 48824, USA.
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