1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Garmash EV. Suppression of mitochondrial alternative oxidase can result in upregulation of the ROS scavenging network: some possible mechanisms underlying the compensation effect. PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:43-53. [PMID: 36245276 DOI: 10.1111/plb.13477] [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: 08/05/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Mitochondrial alternative oxidase is an important protein involved in maintaining cellular metabolic and energy balance, especially under stress conditions. AOX genes knockout is aimed at revealing the functions of AOX genes. Under unfavourable conditions, AOX-suppressed plants (mainly based on Arabidopsis AOX1a-knockout lines) usually experience strong oxidative stress. However, a compensation effect, which consists of the absence of AOX1a leading to an increase in defence response mechanisms, concomitant with a decrease in ROS content, has also been demonstrated. This review briefly describes the possible mechanisms underlying the compensation effect upon the suppression of AOX1a. Information about mitochondrial retrograde regulation of AOX is given. The importance of ROS and mitochondrial membrane potential in triggering the signal transmission from mitochondria in the absence of AOX or disturbance of mitochondrial electron transport chain functions is indicated. The few available data on the response of the cell to the absence of AOX at the level of changes in the hormonal balance and the reactions of chloroplasts are presented. The decrease in the relative amount of reduced ascorbate at stable ROS levels as a result of compensation in AOX1a-suppressed plants is proposed as a sign of stress development. Obtaining direct evidence on the mechanisms and signalling pathways involved in AOX modulation in the genome should facilitate a deeper understanding of the role of AOX in the integration of cellular signalling pathways.
Collapse
Affiliation(s)
- E V Garmash
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| |
Collapse
|
3
|
Garmash EV, Dymova OV, Silina EV, Malyshev RV, Belykh ES, Shelyakin MA, Velegzhaninov IO. AOX1a Expression in Arabidopsis thaliana Affects the State of Chloroplast Photoprotective Systems under Moderately High Light Conditions. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11223030. [PMID: 36432760 PMCID: PMC9697105 DOI: 10.3390/plants11223030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/27/2022] [Accepted: 11/02/2022] [Indexed: 06/01/2023]
Abstract
Alternative oxidase (AOX) in the mitochondrial electron transport chain is considered important for sustaining photosynthesis under high light conditions. Here, we examined the effects of the AOX pathway on the state of chloroplast photoprotective systems. Arabidopsis thaliana plants (4 weeks old), comprising three genotypes (wild type [WT], overexpressing [XX-2] and antisense [AS-12] lines for AOX1a), were exposed to moderately high light conditions (MHL, 400 μmol m-2 s-1) in a short-term experiment (8 h). After 8 h of MHL, the WT and XX-2 plants showed stable non-photochemical quenching (qN) and violaxanthin cycle activity. Antisense plants displayed the lowest level of qN and a lower de-epoxidation state (DEPS) relative to plants of the same line after 4-6 h MHL, as well as compared to WT and XX-2 plants after 8 h MHL. The decline in DEPS in AS-12 plants was attributed to an insufficient violaxanthin de-epoxidase activity, which in turn was associated with a decrease in reduced ascorbate levels in the chloroplasts and leaves. Simultaneously, gene expression and the activity of ascorbate peroxidase in the antisense line increased after 8 h of MHL, supporting the compensatory effect of the antioxidant system when AOX1a expression is suppressed. This study emphasizes the role played by AOX in modulating the photoprotection processes and in the maintenance of relationships between mitochondria and chloroplasts by influencing ascorbate content.
Collapse
|
4
|
Zafari S, Vanlerberghe GC, Igamberdiev AU. The Role of Alternative Oxidase in the Interplay between Nitric Oxide, Reactive Oxygen Species, and Ethylene in Tobacco ( Nicotiana tabacum L.) Plants Incubated under Normoxic and Hypoxic Conditions. Int J Mol Sci 2022; 23:7153. [PMID: 35806157 PMCID: PMC9266549 DOI: 10.3390/ijms23137153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 06/24/2022] [Indexed: 02/05/2023] Open
Abstract
The transgenic tobacco (Nicotiana tabacum L.) plants with the modified levels of alternative oxidase (AOX) were used to evaluate the physiological roles of AOX in regulating nitro-oxidative stress and metabolic changes after exposing plants to hypoxia for 6 h. Under normoxia, AOX expression resulted in the decrease of nitric oxide (NO) levels and of the rate of protein S-nitrosylation, while under hypoxia, AOX overexpressors exhibited higher NO and S-nitrosylation levels than knockdowns. AOX expression was essential in avoiding hypoxia-induced superoxide and H2O2 levels, and this was achieved via higher activities of catalase and glutathione reductase and the reduced expression of respiratory burst oxidase homolog (Rboh) in overexpressors as compared to knockdowns. The AOX overexpressing lines accumulated less pyruvate and exhibited the increased transcript and activity levels of pyruvate decarboxylase and alcohol dehydrogenase under hypoxia. This suggests that AOX contributes to the energy state of hypoxic tissues by stimulating the increase of pyruvate flow into fermentation pathways. Ethylene biosynthesis genes encoding 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, ACC oxidase, and ethylene-responsive factors (ERFs) were induced during hypoxia and correlated with AOX and NO levels. We conclude that AOX controls the interaction of NO, reactive oxygen species, and ethylene, triggering a coordinated downstream defensive response against hypoxia.
Collapse
Affiliation(s)
- Somaieh Zafari
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
| | - Greg C. Vanlerberghe
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada;
- Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada
| | - Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
| |
Collapse
|
5
|
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.
Collapse
Affiliation(s)
| | | | | | | | - Elias Feitosa Araujo
- Institute of Plant Biology and Biotechnology (IBBP), Westfälische Wilhelms-Universität Münster, D-48143 Münster, Germany
| | | | | | | | | | - Andreas J Meyer
- Institute of Crop Science and Resource Conservation (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, D-53113 Bonn, Germany
| | | |
Collapse
|
6
|
Exogenous Melatonin Protects Lime Plants from Drought Stress-Induced Damage by Maintaining Cell Membrane Structure, Detoxifying ROS and Regulating Antioxidant Systems. HORTICULTURAE 2022. [DOI: 10.3390/horticulturae8030257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lime is an important commercial product in tropical and subtropical regions, where drought stress is becoming one of the most severe environmental challenges in the agricultural sector. Melatonin is an antioxidant molecule that helps plants regulate their development and respond to a variety of stresses. In this research, the effects of exogenous melatonin treatments were evaluated at different concentrations (0, 50, 100, and 150 μM) on biochemical aspects and gene expression in two species of lime plants (“Mexican lime” and “Persian lime”) under normal (100% field capacity (FC)) and drought stress conditions (75% and 40% FC). The experiments were factorial and based on a completely randomized design (CRD) with four replicates. Drought stress caused electrolyte leakage (EL) as well as accumulations of hydrogen peroxide (H2O2) and malondialdehyde (MDA), indicating the occurrence of damage to cellular membranes. In contrast, the melatonin pretreatment at various concentrations reduced the levels of EL, H2O2 and MDA while mitigating the negative effects of drought stress on the two lime species. The application of melatonin (100-μM) significantly increased the level of proline content and activity of antioxidant enzymes in plants under drought stress compared to control plants. According to real-time PCR analysis, drought stress and melatonin treatment enhanced the expression of genes involved in ROS scavenging, proline biosynthesis, and cell redox regulation in both species, as compared to their respective controls. According to these findings, melatonin is able to detoxify ROS and regulate antioxidant systems, thereby protecting lime plants from drought stress-induced damages.
Collapse
|
7
|
Kerchev PI, Van Breusegem F. Improving oxidative stress resilience in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:359-372. [PMID: 34519111 DOI: 10.1111/tpj.15493] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/02/2021] [Accepted: 09/08/2021] [Indexed: 05/22/2023]
Abstract
Originally conceived as harmful metabolic byproducts, reactive oxygen species (ROS) are now recognized as an integral part of numerous cellular programs. Thanks to their diverse physicochemical properties, compartmentalized production, and tight control exerted by the antioxidant machinery they activate signaling pathways that govern plant growth, development, and defense. Excessive ROS levels are often driven by adverse changes in environmental conditions, ultimately causing oxidative stress. The associated negative impact on cellular constituents have been a major focus of decade-long research efforts to improve the oxidative stress resilience by boosting the antioxidant machinery in model and crop species. We highlight the role of enzymatic and non-enzymatic antioxidants as integral factors of multiple signaling cascades beyond their mere function to prevent oxidative damage under adverse abiotic stress conditions.
Collapse
Affiliation(s)
- Pavel I Kerchev
- Phytophthora Research Centre, Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, 61300, Brno, Czech Republic
| | - Frank Van Breusegem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052, Gent, Belgium
| |
Collapse
|
8
|
Rodrigues L, Nogales A, Hansen LD, Santos F, Rato AE, Cardoso H. Exploring the Applicability of Calorespirometry to Assess Seed Metabolic Stability Upon Temperature Stress Conditions- Pisum sativum L. Used as a Case Study. FRONTIERS IN PLANT SCIENCE 2022; 13:827117. [PMID: 35574105 PMCID: PMC9094064 DOI: 10.3389/fpls.2022.827117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/24/2022] [Indexed: 05/17/2023]
Abstract
The availability of phenotyping tools to assist breeding programs in the selection of high-quality crop seeds is of obvious interest with consequences for both seed producers and consumers. Seed germination involves the activation of several metabolic pathways, such as cellular respiration to provide the required ATP and reducing power. This work tested the applicability of calorespirometry, the simultaneous measurement of heat and CO2 rates, as a phenotyping tool to assess seed respiratory properties as a function of temperature. The effect of temperature on seed germination was evaluated after 16 h of seed imbibition by calorespirometric experiments performed in isothermal mode at 15, 20, 25, and 28°C on the seeds of three cultivars of peas (Pisum sativum L.) commonly used in conventional agriculture (cvs. 'Rondo', 'Torta de Quebrar', and 'Maravilha d'América'). Significant differences in metabolic heat rate and CO2 production rate (R CO2 ) as well as in the temperature responses of these parameters were found among the three cultivars. A seed germination trial was conducted during the 6 days of imbibition to evaluate the predictive power of the parameters derived from the calorespirometric measurements. The germination trial showed that the optimal germination temperature was 20°C and low germination rates were observed at extreme temperatures (15 or 28°C). The cv. 'Torta de Quebrar' showed significantly higher germination in comparison with the other two cultivars at all three temperatures. In comparison with the other two cultivars, 'Torta de Quebrar' has the lowest metabolic heat and CO2 rates and the smallest temperature dependence of these measured parameters. Additionally, 'Torta de Quebrar' has the lowest values of growth rate and carbon use efficiency calculated from the measured variables. These data suggest that calorespirometry is a useful tool for phenotyping physiologic efficiency at different temperatures during early germination stages, and can determine the seeds with the highest resilience to temperature variation, in this case 'Torta de Quebrar'.
Collapse
Affiliation(s)
- Lénia Rodrigues
- Mediterranean Institute for Agriculture, Environment and Development, Instituto de Formação e Investigação Avançada, Universidade de Évora, Évora, Portugal
| | - Amaia Nogales
- Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon, Portugal
| | - Lee D. Hansen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, United States
| | - Fátima Santos
- Centro Nacional de Biotecnología, Unidad de Proteomica, CSIC, Calle Darwin 3, Madrid, Spain
| | - Ana Elisa Rato
- Mediterranean Institute for Agriculture, Environment and Development, Departamento de Fitotecnia, Escola de Ciências e Tecnologia, Universidade de Évora, Évora, Portugal
| | - Hélia Cardoso
- Mediterranean Institute for Agriculture, Environment and Development, Instituto de Formação e Investigação Avançada, Universidade de Évora, Évora, Portugal
- *Correspondence: Hélia Cardoso,
| |
Collapse
|
9
|
Tussipkan D, Manabayeva SA. Employing CRISPR/Cas Technology for the Improvement of Potato and Other Tuber Crops. FRONTIERS IN PLANT SCIENCE 2021; 12:747476. [PMID: 34764969 PMCID: PMC8576567 DOI: 10.3389/fpls.2021.747476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/04/2021] [Indexed: 05/07/2023]
Abstract
New breeding technologies have not only revolutionized biological science, but have also been employed to generate transgene-free products. Genome editing is a powerful technology that has been used to modify genomes of several important crops. This review describes the basic mechanisms, advantages and disadvantages of genome editing systems, such as ZFNs, TALENs, and CRISPR/Cas. Secondly, we summarize in detail all studies of the CRISPR/Cas system applied to potato and other tuber crops, such as sweet potato, cassava, yam, and carrot. Genes associated with self-incompatibility, abiotic-biotic resistance, nutrient-antinutrient content, and post-harvest factors targeted utilizing the CRISPR/Cas system are analyzed in this review. We hope that this review provides fundamental information that will be useful for future breeding of tuber crops to develop novel cultivars.
Collapse
Affiliation(s)
| | - Shuga A. Manabayeva
- Plant Genetic Engineering Laboratory, National Center for Biotechnology, Nur-Sultan, Kazakhstan
| |
Collapse
|
10
|
Hou L, Zhao M, Huang C, He Q, Zhang L, Zhang J. Alternative oxidase gene induced by nitric oxide is involved in the regulation of ROS and enhances the resistance of Pleurotus ostreatus to heat stress. Microb Cell Fact 2021; 20:137. [PMID: 34281563 PMCID: PMC8287771 DOI: 10.1186/s12934-021-01626-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 07/04/2021] [Indexed: 12/13/2022] Open
Abstract
Background In China, during the cultivation process of Pleurotus ostreatus, the yield and quality of fruiting bodies are easily affected by high temperatures in summer. Nitric oxide (NO) plays an important regulatory role in the response to abiotic stress, and previous studies have found that NO can induce alternative oxidase (aox) experssion in response to heat stress (HS) by regulating aconitase. However, the regulatory pathway of NO is complex, and the function and regulation of the aox gene in the response to HS remain unclear. Results In this study, we found that NO affected nicotinamide adenine dinucleotide (NADH) and adenosine triphosphate (ATP) levels, reduced hydrogen peroxide (H2O2) and superoxide anion (O2−) contents, and slowed O2− production. Further RNA-Seq results showed that NO regulated the oxidation-reduction process and oxidoreductase activity, affected the cellular respiration pathway and activated aox gene expression. The function of aox was determined by constructing overexpression (OE) and RNA interference (RNAi) strains. The results showed that the OE-aox strains exhibited obviously improved growth recovery after exposure to HS. During exposure to HS, the OE-aox strains exhibited reduced levels of NADH, the product of the tricarboxylic acid (TCA) cycle, and decreased synthesis of ATP, which reduced the production and accumulation of reactive oxygen species (ROS), whereas the RNAi-aox strains exhibited the opposite result. In addition, aox mediated the expression of antioxidant enzyme genes in the mycelia of P. ostreatus under HS through the retrograde signaling pathway. Conclusions This study shows that the expression of the aox gene in P. ostreatus mycelia can be induced by NO under HS, that it regulates the TCA cycle and cell respiration to reduce the production of ROS, and that it can mediate the retrograde signaling pathway involved in the mycelial response to HS. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01626-y.
Collapse
Affiliation(s)
- Ludan Hou
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China
| | - Mengran Zhao
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China
| | - Chenyang Huang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China
| | - Qi He
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China.,Jilin Agricultural University, 130118, Jilin, China
| | - Lijiao Zhang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China
| | - Jinxia Zhang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China. .,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China.
| |
Collapse
|
11
|
Liu Y, Yu LL, Peng Y, Geng XX, Xu F. Alternative Oxidase Inhibition Impairs Tobacco Root Development and Root Hair Formation. FRONTIERS IN PLANT SCIENCE 2021; 12:664792. [PMID: 34249036 PMCID: PMC8264555 DOI: 10.3389/fpls.2021.664792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 04/13/2021] [Indexed: 06/13/2023]
Abstract
Alternative oxidase (AOX) is the terminal oxidase of the mitochondrial respiratory electron transport chain in plant cells and is critical for the balance of mitochondrial hemostasis. In this study, the effect of inhibition of AOX with different concentrations of salicylhydroxamic acid (SHAM) on the tobacco root development was investigated. We show here that AOX inhibition significantly impaired the development of the main root and root hair formation of tobacco. The length of the main root of SHAM-treated tobacco was significantly shorter than that of the control, and no root hairs were formed after treatment with a concentration of 1 mM SHAM or more. The transcriptome analysis showed that AOX inhibition by 1 mM SHAM involved in the regulation of gene expression related to root architecture. A total of 5,855 differentially expressed genes (DEGs) were obtained by comparing SHAM-treated roots with control. Of these, the gene expression related to auxin biosynthesis and perception were significantly downregulated by 1 mM SHAM. Similarly, genes related to cell wall loosening, cell cycle, and root meristem growth factor 1 (RGF1) also showed downregulation on SHAM treatment. Moreover, combined with the results of physiological measurements, the transcriptome analysis demonstrated that AOX inhibition resulted in excessive accumulation of reactive oxygen species in roots, which further induced oxidative damage and cell apoptosis. It is worth noting that when indoleacetic acid (20 nM) and dimethylthiourea (10 mM) were added to the medium containing SHAM, the defects of tobacco root development were alleviated, but to a limited extent. Together, these findings indicated that AOX-mediated respiratory pathway plays a crucial role in the tobacco root development, including root hair formation.
Collapse
Affiliation(s)
- Yang Liu
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
| | - Lu-Lu Yu
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
| | - Ye Peng
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
- Biotechnology Research Center, China Three Gorges University, Yichang, China
| | - Xin-Xin Geng
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
| | - Fei Xu
- Applied Biotechnology Center, Wuhan University of Bioengineering, Wuhan, China
| |
Collapse
|
12
|
Garmash EV, Belykh ES, Velegzhaninov IO. The gene expression profiles of mitochondrial respiratory components in Arabidopsis plants with differing amounts of ALTERNATIVE OXIDASE1a under high intensity light. PLANT SIGNALING & BEHAVIOR 2021; 16:1864962. [PMID: 33369529 PMCID: PMC7889022 DOI: 10.1080/15592324.2020.1864962] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We compared the expression of mitochondrial alternative oxidase (AOX) and other non-phosphorylating respiratory components (NPhPs) in wild type and AOX1a transgenic Arabidopsis thaliana following short-term transfer of plants to higher irradiance conditions to gain more insight into the mechanisms of AOX functioning under light. The AOX1a overexpressing line (XX-2) showed the highest amount of AOX1a transcripts and AOX1A synthesis during the entire experiment, and many NPhPs genes were down-regulated after 6-8 h under the higher light conditions. Antisense AS-12 plants displayed a compensatory effect, typically after 8 h of exposure to higher irradiance, by up-regulating their expression of the majority of genes encoding AOX and other respiratory components. In addition, AS-12 plants displayed 'overcompensation effects' prior to their transfer to high light conditions, i.e., they showed a higher expression level of certain genes. As a result, the ROS content in AS-12, as in XX-2, was consistently lower than in the wild type. All NPhPs genes share, in common with AOX1a, light- and stress-related cis-acting regulatory elements (CAREs) in their promoters. However, the expression of respiratory genes does not always depend on the level of AOX1a expression. This suggests the presence of multiple combinations of signaling pathways in gene induction. Based on our results, we outline possible directions for future research.
Collapse
Affiliation(s)
- Elena V. Garmash
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
- CONTACT Elena V. Garmash Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Elena S. Belykh
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Ilya O. Velegzhaninov
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| |
Collapse
|
13
|
Garmash EV. Role of mitochondrial alternative oxidase in the regulation of cellular homeostasis during development of photosynthetic function in greening leaves. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:221-228. [PMID: 33190385 DOI: 10.1111/plb.13217] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/08/2020] [Indexed: 05/27/2023]
Abstract
Here, recent publications on the role of mitochondrial non-phosphorylating pathways (NPhPs) in the electron transport chain during the de-etiolation of wheat leaves are reviewed. Among NPhPs, the alternative oxidase (AOX) pathway is the most effective pathway in maintaining cellular redox and energy balance, especially under stress conditions, including light stress. AOX is considered to dissipate excess reductants produced in the chloroplasts, and thereby prevent photooxidation. However, when etiolated wheat plants were exposed to a physiologically relevant light level, AOX was rapidly induced and increased, although the etioplasts did not produce excess reductants and have their own strong photoprotective mechanisms. The present study provides further insights into the role of AOX in greening cells and highlights the importance of AOX in the integration of cellular signalling pathways.
Collapse
Affiliation(s)
- E V Garmash
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, 167982, Russian Federation
| |
Collapse
|
14
|
Zafari S, Vanlerberghe GC, Igamberdiev AU. Nitric Oxide Turnover Under Hypoxia Results in the Rapid Increased Expression of the Plastid-Localized Phosphorylated Pathway of Serine Biosynthesis. FRONTIERS IN PLANT SCIENCE 2021; 12:780842. [PMID: 35173748 PMCID: PMC8841671 DOI: 10.3389/fpls.2021.780842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/28/2021] [Indexed: 05/03/2023]
Abstract
The plant mitochondrial electron transport chain influences carbon and nitrogen metabolism under near anoxic conditions through its involvement in the phytoglobin-nitric oxide cycle, where the respiratory chain reduces nitrite to nitric oxide (NO), followed by NO conversion to nitrate by class 1 phytoglobin. Wild type (WT) and transgenic tobacco (Nicotiana tabacum L.) with differing amounts of alternative oxidase (AOX) were used to manipulate NO generation under hypoxia, and to examine whether this in turn influenced the gene expression of two stress-related amino acid biosynthetic pathways, the plastid-localized phosphorylated pathway of serine biosynthesis (PPSB), and the γ-aminobutyric acid (GABA) shunt. Under hypoxia, leaf NO emission rate was highest in AOX overexpressors and lowest in AOX knockdowns, with WT showing an intermediate rate. In turn, the rate of NO emission correlated with the degree to which amino acids accumulated. This amino acid accumulation was associated with the increased expression of the enzymes of the stress-related amino acid biosynthetic pathways. However, induction of the PPSB occurred much earlier than the GABA shunt. This work shows that high rates of NO turnover associate with rapid gene induction of the PPSB, establishing a clear link between this pathway and the maintenance of carbon, nitrogen and energy metabolism under hypoxia.
Collapse
Affiliation(s)
- Somaieh Zafari
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Greg C. Vanlerberghe
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
- *Correspondence: Abir U. Igamberdiev,
| |
Collapse
|
15
|
Romero-Aguilar L, Cárdenas-Monroy C, Garrido-Bazán V, Aguirre J, Guerra-Sánchez G, Pardo JP. On the use of n-octyl gallate and salicylhydroxamic acid to study the alternative oxidase role. Arch Biochem Biophys 2020; 694:108603. [PMID: 32986977 DOI: 10.1016/j.abb.2020.108603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/28/2020] [Accepted: 09/24/2020] [Indexed: 10/23/2022]
Abstract
The alternative oxidase (AOX) catalyzes the transfer of electrons from ubiquinol to oxygen without the translocation of protons across the inner mitochondrial membrane. This enzyme has been proposed to participate in the regulation of cell growth, sporulation, yeast-mycelium transition, resistance to reactive oxygen species, infection, and production of secondary metabolites. Two approaches have been used to evaluate AOX function: incubation of cells for long periods of time with AOX inhibitors or deletion of AOX gene. However, AOX inhibitors might have different targets. To test non-specific effects of n-octyl gallate (nOg) and salicylhydroxamic acid (SHAM) on fungal physiology we measured the growth and respiratory capacity of two fungal strains lacking (Ustilago maydis-Δaox and Saccharomyces cerevisiae) and three species containing the AOX gene (U. maydis WT, Debaryomyces hansenii, and Aspergillus nidulans). For U. maydis, a strong inhibition of growth and respiratory capacity by SHAM was observed, regardless of the presence of AOX. Similarly, A. nidulans mycelial growth was inhibited by low concentrations of nOg independently of AOX expression. In contrast, these inhibitors had no effect or had a minor effect on S. cerevisiae and D. hansenii growth. These results show that nOg and SHAM have AOX independent effects which vary in different microorganisms, indicating that studies based on long-term incubation of cells with these inhibitors should be considered as inconclusive.
Collapse
Affiliation(s)
- Lucero Romero-Aguilar
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, 04510, Ciudad de México, Mexico
| | - Christian Cárdenas-Monroy
- Ciencia Forense, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, 04510, Ciudad de México, Mexico
| | - Verónica Garrido-Bazán
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, 04510, Ciudad de México, Mexico
| | - Jesus Aguirre
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, 04510, Ciudad de México, Mexico
| | - Guadalupe Guerra-Sánchez
- Departamento de Microbiología, Laboratorio de Bioquímica y Biotecnología de Hongos, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Carpio y Plan de Ayala S/N., Miguel Hidalgo, 11350, Ciudad de México, Mexico
| | - Juan Pablo Pardo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, 04510, Ciudad de México, Mexico.
| |
Collapse
|
16
|
Chadee A, Vanlerberghe GC. Distinctive mitochondrial and chloroplast components contributing to the maintenance of carbon balance during plant growth at elevated CO 2. PLANT SIGNALING & BEHAVIOR 2020; 15:1795395. [PMID: 32705929 PMCID: PMC8550537 DOI: 10.1080/15592324.2020.1795395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Plant carbon balance depends upon the difference between photosynthetic carbon gain and respiratory carbon loss. In C3 plants, growth at an elevated atmospheric concentration of CO2 (ECO2) stimulates photosynthesis and raises the leaf carbohydrate status, but how respiration responds is less understood. In this study, growth of Nicotiana tabacum at ECO2 increased the protein amount of the non-energy conserving mitochondrial alternative oxidase (AOX). Growth at ECO2 increased AOX1a transcript amount, and the transcript amount of a putative sugar-responsive gene encoding a chloroplast glucose-6-phosphate/phosphate translocator (GPT3). We suggest that the elevated amounts of AOX and GPT3 represent distinctive mitochondrial and chloroplast mechanisms to manage an excessive cytosolic pool of sugar phosphates. AOX respiration could consume cytosolic sugar phosphates, without this activity being restricted by rates of ATP turnover. GPT3 could allow accumulating cytosolic glucose-6-phosphate to return to the chloroplast. This could feed starch synthesis or a glucose-6-phosphate shunt in the Calvin cycle. AOX and GPT3 activities could buffer against Pi depletions that might otherwise disrupt mitochondrial and chloroplast electron transport chain activities. AOX and GPT3 activities could also buffer against a down-regulation of photosynthetic capacity by preventing a persistent imbalance between photosynthetic carbon gain and the activity of carbon utilizing sinks.
Collapse
Affiliation(s)
- Avesh Chadee
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Greg C. Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
- CONTACT Greg C. Vanlerberghe Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ONM1C1A4, Canada
| |
Collapse
|
17
|
Bartholomew DC, Bittencourt PRL, da Costa ACL, Banin LF, de Britto Costa P, Coughlin SI, Domingues TF, Ferreira LV, Giles A, Mencuccini M, Mercado L, Miatto RC, Oliveira A, Oliveira R, Meir P, Rowland L. Small tropical forest trees have a greater capacity to adjust carbon metabolism to long-term drought than large canopy trees. PLANT, CELL & ENVIRONMENT 2020; 43:2380-2393. [PMID: 32643169 DOI: 10.1111/pce.13838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
The response of small understory trees to long-term drought is vital in determining the future composition, carbon stocks and dynamics of tropical forests. Long-term drought is, however, also likely to expose understory trees to increased light availability driven by drought-induced mortality. Relatively little is known about the potential for understory trees to adjust their physiology to both decreasing water and increasing light availability. We analysed data on maximum photosynthetic capacity (Jmax , Vcmax ), leaf respiration (Rleaf ), leaf mass per area (LMA), leaf thickness and leaf nitrogen and phosphorus concentrations from 66 small trees across 12 common genera at the world's longest running tropical rainfall exclusion experiment and compared responses to those from 61 surviving canopy trees. Small trees increased Jmax , Vcmax , Rleaf and LMA (71, 29, 32, 15% respectively) in response to the drought treatment, but leaf thickness and leaf nutrient concentrations did not change. Small trees were significantly more responsive than large canopy trees to the drought treatment, suggesting greater phenotypic plasticity and resilience to prolonged drought, although differences among taxa were observed. Our results highlight that small tropical trees have greater capacity to respond to ecosystem level changes and have the potential to regenerate resilient forests following future droughts.
Collapse
Affiliation(s)
- David C Bartholomew
- School of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Paulo R L Bittencourt
- School of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | | | | | | | - Sarah I Coughlin
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Tomas F Domingues
- Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - André Giles
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | - Maurizio Mencuccini
- ICREA, Barcelona, Spain
- CREAF, Universidad Autonoma de Barcelona, Barcelona, Spain
| | - Lina Mercado
- School of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
- UK Centre for Ecology and Hydrology, Wallingford, UK
| | - Raquel C Miatto
- Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Rafael Oliveira
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | - Patrick Meir
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - Lucy Rowland
- School of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| |
Collapse
|
18
|
Zhao Y, Yu H, Zhou JM, Smith SM, Li J. Malate Circulation: Linking Chloroplast Metabolism to Mitochondrial ROS. TRENDS IN PLANT SCIENCE 2020; 25:446-454. [PMID: 32304657 DOI: 10.1016/j.tplants.2020.01.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/29/2019] [Accepted: 01/27/2020] [Indexed: 05/02/2023]
Abstract
In photosynthetic cells, chloroplasts and mitochondria are the sites of the core redox reactions underpinning energy metabolism. Such reactions generate reactive oxygen species (ROS) when oxygen is partially reduced. ROS signaling leads to responses by cells which enable them to adjust to changes in redox status. Recent studies in Arabidopsis thaliana reveal that chloroplast NADH can be used to generate malate which is exported to the mitochondrion where its oxidation regenerates NADH. Oxidation of this NADH produces mitochondrial ROS (mROS) which can activate signaling systems to modulate energy metabolism, and in certain cases can lead to programmed cell death (PCD). We propose the term 'malate circulation' to describe such redistribution of reducing equivalents to mediate energy homeostasis in the cell.
Collapse
Affiliation(s)
- Yannan Zhao
- State Key Laboratory of Plant Genomics, and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Hong Yu
- State Key Laboratory of Plant Genomics, and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Jian-Min Zhou
- State Key Laboratory of Plant Genomics, and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Steven M Smith
- State Key Laboratory of Plant Genomics, and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia.
| | - Jiayang Li
- State Key Laboratory of Plant Genomics, and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Garmash EV, Velegzhaninov IO, Ermolina KV, Rybak AV, Malyshev RV. Altered levels of AOX1a expression result in changes in metabolic pathways in Arabidopsis thaliana plants acclimated to low dose rates of ultraviolet B radiation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 291:110332. [PMID: 31928662 DOI: 10.1016/j.plantsci.2019.110332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/28/2019] [Accepted: 11/02/2019] [Indexed: 05/27/2023]
Abstract
UV-B is a damaging component of solar radiation that inevitably reaches the Earth's surface. Plants have developed response mechanisms to adapt to UVB exposure. The alternative oxidase (AOX) catalyzes the ATP-uncoupling cyanide-resistant alternative pathway (AP) in plant mitochondria and is thought to be an important part of the cellular defense network under stress conditions. This study aimed to unravel the poorly understood functional significance of AOX1a induction in Arabidopsis thaliana leaves exposed to ecologically relevant doses of UVB radiation, by comparing wild-type (WT) plants with plants with modified expression of the AOX1a gene, either downregulated by antisense (AS-12) or overexpressed (XX-2). UVB exposure resulted in a phenotypic difference between lines. AOX1a overexpression resulted in the highest induction of AOX1A synthesis and MnSOD activity, and the lowest ROS level without pronounced changes in the phenotype relative to other genotypes. In AS-12 plants, expression of the majority of the genes encoding AOX was detected, other non-phosphorylating pathway components and antioxidant enzymes increased along with anthocyanin accumulation in leaves, and the ROS content was lower than in the WT. In addition to the expected AOX1 protein size (34 kDa), an AOX1 30 kDa band appeared under UVB exposure in all genotypes. However, in AS-12, the alterations in the transcript level and in the abundance of AOX1 protein isoforms induced by UVB could not fully functionally compensate for the lack of AOX1A. This was confirmed by the observed low AP capacity and increased levels of the oxidized form of ascorbate. These results highlight the importance of AOX in plant response to UVB for the control of a balanced metabolism, and indicate that AOX1a plays a key role in the regulation of the stress response.
Collapse
Affiliation(s)
- Elena V Garmash
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia.
| | - Ilya O Velegzhaninov
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Ksenia V Ermolina
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Anna V Rybak
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Ruslan V Malyshev
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| |
Collapse
|
21
|
Jayawardhane J, Cochrane DW, Vyas P, Bykova NV, Vanlerberghe GC, Igamberdiev AU. Roles for Plant Mitochondrial Alternative Oxidase Under Normoxia, Hypoxia, and Reoxygenation Conditions. FRONTIERS IN PLANT SCIENCE 2020; 11:566. [PMID: 32499803 PMCID: PMC7243820 DOI: 10.3389/fpls.2020.00566] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/16/2020] [Indexed: 05/19/2023]
Abstract
Alternative oxidase (AOX) is a non-energy conserving terminal oxidase in the plant mitochondrial electron transport chain (ETC) that has a lower affinity for oxygen than does cytochrome (cyt) oxidase. To investigate the role(s) of AOX under different oxygen conditions, wild-type (WT) Nicotiana tabacum plants were compared with AOX knockdown and overexpression plants under normoxia, hypoxia (near-anoxia), and during a reoxygenation period following hypoxia. Paradoxically, under all the conditions tested, the AOX amount across plant lines correlated positively with leaf energy status (ATP/ADP ratio). Under normoxia, AOX was important to maintain respiratory carbon flow, to prevent the mitochondrial generation of superoxide and nitric oxide (NO), to control lipid peroxidation and protein S-nitrosylation, and possibly to reduce the inhibition of cyt oxidase by NO. Under hypoxia, AOX was again important in preventing superoxide generation and lipid peroxidation, but now contributed positively to NO amount. This may indicate an ability of AOX to generate NO under hypoxia, similar to the nitrite reductase activity of cyt oxidase under hypoxia. Alternatively, it may indicate that AOX activity simply reduces the amount of superoxide scavenging of NO, by reducing the availability of superoxide. The amount of inactivation of mitochondrial aconitase during hypoxia was also dependent upon AOX amount, perhaps through its effects on NO amount, and this influenced carbon flow under hypoxia. Finally, AOX was particularly important in preventing nitro-oxidative stress during the reoxygenation period, thereby contributing positively to the recovery of energy status following hypoxia. Overall, the results suggest that AOX plays a beneficial role in low oxygen metabolism, despite its lower affinity for oxygen than cytochrome oxidase.
Collapse
Affiliation(s)
| | - Devin W. Cochrane
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Poorva Vyas
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Natalia V. Bykova
- Morden Research and Development Centre, Agriculture and Agri-Food Canada, Morden, MB, Canada
| | - Greg C. Vanlerberghe
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
- *Correspondence: Abir U. Igamberdiev,
| |
Collapse
|
22
|
Kolupaev YE, Karpets YV, Kabashnikova LF. Antioxidative System of Plants: Cellular Compartmentalization, Protective and Signaling Functions, Mechanisms of Regulation (Review). APPL BIOCHEM MICRO+ 2019. [DOI: 10.1134/s0003683819050089] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
23
|
Acevedo RM, Avico EH, González S, Salvador AR, Rivarola M, Paniego N, Nunes-Nesi A, Ruiz OA, Sansberro PA. Transcript and metabolic adjustments triggered by drought in Ilex paraguariensis leaves. PLANTA 2019; 250:445-462. [PMID: 31055624 DOI: 10.1007/s00425-019-03178-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 04/27/2019] [Indexed: 06/09/2023]
Abstract
Abscisic acid is involved in the drought response of Ilex paraguariensis. Acclimation includes root growth stimulation, stomatal closure, osmotic adjustment, photoprotection, and regulation of nonstructural carbohydrates and amino acid metabolisms. Ilex paraguariensis (yerba mate) is cultivated in the subtropical region of South America, where the occurrence of drought episodes limit yield. To explore the mechanisms that allow I. paraguariensis to overcome dehydration, we investigated (1) how gene expression varied between water-stressed and non-stressed plants and (2) in what way the modulation of gene expression was linked to physiological status and metabolite composition. A total of 4920 differentially expressed transcripts were obtained through RNA-Seq after water deprivation. Drought induced the expression of several transcripts involved in the ABA-signalling pathway. Stomatal closure and leaf osmotic adjustments were promoted to minimize water loss, and these responses were accompanied by a high transcriptional remodeling of stress perception, signalling and transcriptional regulation, the photoprotective and antioxidant systems, and other stress-responsive genes. Simultaneously, significant changes in metabolite contents were detected. Glutamine, phenylalanine, isomaltose, fucose, and malate levels were shown to be positively correlated with dehydration. Principal component analysis showed differences in the metabolic profiles of control and stressed leaves. These results provide a comprehensive overview of how I. paraguariensis responds to dehydration at transcriptional and metabolomic levels and provide further characterization of the molecular mechanisms associated with drought response in perennial subtropical species.
Collapse
Affiliation(s)
- Raúl M Acevedo
- Laboratorio de Biotecnología Aplicada y Genómica Funcional. Facultad de Ciencias Agrarias, Instituto de Botánica del Nordeste (IBONE-CONICET), Universidad Nacional del Nordeste, W3402BKG, Corrientes, Argentina
| | - Edgardo H Avico
- Laboratorio de Biotecnología Aplicada y Genómica Funcional. Facultad de Ciencias Agrarias, Instituto de Botánica del Nordeste (IBONE-CONICET), Universidad Nacional del Nordeste, W3402BKG, Corrientes, Argentina
| | - Sergio González
- Instituto de Biotecnología, CICVyA (INTA), 1686, Hurlingham, Buenos Aires, Argentina
| | | | - Máximo Rivarola
- Instituto de Biotecnología, CICVyA (INTA), 1686, Hurlingham, Buenos Aires, Argentina
| | - Norma Paniego
- Instituto de Biotecnología, CICVyA (INTA), 1686, Hurlingham, Buenos Aires, Argentina
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, MG, Brazil
| | - Oscar A Ruiz
- Unidad de Biotecnología 1, IIB-INTECH (UNSAM-CONICET), B7130IWA, Chascomús, Argentina
- Instituto de Fisiología y Recursos Genéticos Vegetales (IFRGV) "Ing. Victorio S. Trippi" (CIAP-INTA), X5020ICA, Córdoba, Argentina
| | - Pedro A Sansberro
- Laboratorio de Biotecnología Aplicada y Genómica Funcional. Facultad de Ciencias Agrarias, Instituto de Botánica del Nordeste (IBONE-CONICET), Universidad Nacional del Nordeste, W3402BKG, Corrientes, Argentina.
| |
Collapse
|
24
|
He H, Oo TL, Huang W, He LF, Gu M. Nitric oxide acts as an antioxidant and inhibits programmed cell death induced by aluminum in the root tips of peanut (Arachis hypogaea L.). Sci Rep 2019; 9:9516. [PMID: 31267033 PMCID: PMC6606607 DOI: 10.1038/s41598-019-46036-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 06/17/2019] [Indexed: 11/09/2022] Open
Abstract
Aluminum (Al) causes programmed cell death (PCD) in plants. Our previous studies have confirmed that nitric oxide (NO) inhibits Al-induced PCD in the root tips of peanut. However, the mechanism by which NO inhibits Al-induced PCD is unclear. Here the effects of NO on mitochondrial reactive oxygen species (ROS), malondialdehyde (MDA), activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX), expression of alternative oxidase (AhAOX) and cytochrome oxidase (AhCOX) were investigated in peanut (Arachis hypogaea L.) root tips treated with Al. The results showed that Al stress induced rapid accumulation of H2O2 and MDA and increased the ratio of SOD/APX. The up-regulation of AhAOX and AhCOX expressions was not enough to inhibit PCD occurrence. Sodium nitroprusside (SNP, a NO donor) decreased the ratio of SOD/APX and eliminated excess H2O2 and MDA, thereby inhibiting Al-induced PCD in the root tips of peanut. The expression of AhAOX and AhCOX was significantly enhanced in Al-induced PCD treated with SNP. But cPTIO (a NO specific scavenger) supply had the opposite effect. Taken together, these results suggested that lipid peroxidation induced by higher levels of H2O2 was an important cause of Al-induced PCD. NO-mediated inhibition of Al-induced PCD was related to a significant elimination of H2O2 accumulation by decreasing the ratio of SOD/APX and up-regulating the expression of AhAOX and AhCOX.
Collapse
Affiliation(s)
- Huyi He
- College of Agronomy, Guangxi University, Nanning, 530004, P.R. China.,Cash Crops Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, 530007, P.R. China
| | - Thet Lwin Oo
- College of Agronomy, Guangxi University, Nanning, 530004, P.R. China
| | - Wenjing Huang
- College of Agronomy, Guangxi University, Nanning, 530004, P.R. China
| | - Long-Fei He
- College of Agronomy, Guangxi University, Nanning, 530004, P.R. China. .,Guangxi Key Laboratory for Agro-Environment and Agro-Product Safety, Nanning, 530004, P.R. China.
| | - Minghua Gu
- College of Agronomy, Guangxi University, Nanning, 530004, P.R. China
| |
Collapse
|
25
|
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.
Collapse
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
| |
Collapse
|
26
|
Woldesemayat AA, Van Heusden P, Ndimba BK, Christoffels A. An integrated and comparative approach towards identification, characterization and functional annotation of candidate genes for drought tolerance in sorghum (Sorghum bicolor (L.) Moench). BMC Genet 2017; 18:119. [PMID: 29273003 PMCID: PMC5741957 DOI: 10.1186/s12863-017-0584-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 12/06/2017] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Drought is the most disastrous abiotic stress that severely affects agricultural productivity worldwide. Understanding the biological basis of drought-regulated traits, requires identification and an in-depth characterization of genetic determinants using model organisms and high-throughput technologies. However, studies on drought tolerance have generally been limited to traditional candidate gene approach that targets only a single gene in a pathway that is related to a trait. In this study, we used sorghum, one of the model crops that is well adapted to arid regions, to mine genes and define determinants for drought tolerance using drought expression libraries and RNA-seq data. RESULTS We provide an integrated and comparative in silico candidate gene identification, characterization and annotation approach, with an emphasis on genes playing a prominent role in conferring drought tolerance in sorghum. A total of 470 non-redundant functionally annotated drought responsive genes (DRGs) were identified using experimental data from drought responses by employing pairwise sequence similarity searches, pathway and interpro-domain analysis, expression profiling and orthology relation. Comparison of the genomic locations between these genes and sorghum quantitative trait loci (QTLs) showed that 40% of these genes were co-localized with QTLs known for drought tolerance. The genome reannotation conducted using the Program to Assemble Spliced Alignment (PASA), resulted in 9.6% of existing single gene models being updated. In addition, 210 putative novel genes were identified using AUGUSTUS and PASA based analysis on expression dataset. Among these, 50% were single exonic, 69.5% represented drought responsive and 5.7% were complete gene structure models. Analysis of biochemical metabolism revealed 14 metabolic pathways that are related to drought tolerance and also had a strong biological network, among categories of genes involved. Identification of these pathways, signifies the interplay of biochemical reactions that make up the metabolic network, constituting fundamental interface for sorghum defence mechanism against drought stress. CONCLUSIONS This study suggests untapped natural variability in sorghum that could be used for developing drought tolerance. The data presented here, may be regarded as an initial reference point in functional and comparative genomics in the Gramineae family.
Collapse
Affiliation(s)
- Adugna Abdi Woldesemayat
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Belleville, 7535, South Africa.
- Department of Life and Consumer Sciences, College of Agriculture and Environmental Sciences, University of South Africa, UNISA Science Campus, Corner of Christiaan De Wet Road and Pioneer Avenue, Johannesburg, Florida, 1710, South Africa.
| | - Peter Van Heusden
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Belleville, 7535, South Africa
| | - Bongani K Ndimba
- Department of Biotechnology, University of the Western Cape, Private Bag X17, Belleville, Cape Town, 7535, South Africa
- Agricultural Research Council, Infruitech-Nietvoorbij, Private Bag X5026, Stellenbosch, 7599, South Africa
| | - Alan Christoffels
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Belleville, 7535, South Africa
| |
Collapse
|
27
|
Zegaoui Z, Planchais S, Cabassa C, Djebbar R, Belbachir OA, Carol P. Variation in relative water content, proline accumulation and stress gene expression in two cowpea landraces under drought. JOURNAL OF PLANT PHYSIOLOGY 2017; 218:26-34. [PMID: 28763706 DOI: 10.1016/j.jplph.2017.07.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/02/2017] [Accepted: 07/03/2017] [Indexed: 05/09/2023]
Abstract
Many landraces of cowpea [Vigna unguiculata (L.) Walp.] are adapted to particular geographical and climatic conditions. Here we describe two landraces grown respectively in arid and temperate areas of Algeria and assess their physiological and molecular responses to drought stress. As expected, when deprived of water cowpea plants lose water over time with a gradual reduction in transpiration rate. The landraces differed in their relative water content (RWC) and whole plant transpiration rate. The landrace from Menia, an arid area, retained more water in adult leaves. Both landraces responded to drought stress at the molecular level by increasing expression of stress-related genes in aerial parts, including proline metabolism genes. Expression of gene(s) encoding proline synthesis enzyme P5CS was up regulated and gene expression of ProDH, a proline catabolism enzyme, was down regulated. Relatively low amounts of proline accumulated in adult leaves with slight differences between the two landraces. During drought stress the most apical part of plants stayed relatively turgid with a high RWC compared to distal parts that wilted. Expression of key stress genes was higher and more proline accumulated at the apex than in distal leaves indicating that cowpea has a non-uniform stress response at the whole plant level. Our study reveals a developmental control of water stress through preferential proline accumulation in the upper tier of the cowpea plant. We also conclude that cowpea landraces display physiological adaptations to water stress suited to the arid and temperate climates in which they are cultivated.
Collapse
Affiliation(s)
- Zahia Zegaoui
- Sorbonne Universités, UPMC Univ Paris 06, iEES, UMR 7618, (UPEC, UPMC, CNRS, IRD, INRA, Paris Diderot), case 237, 4 place Jussieu, F-75252, Paris cedex 05, France; Laboratory of Biology and Physiology of Organisms, Faculty of Biological Sciences, Houari Boumediene University of Sciences and Technology, BP 32, El Alia 16111, Algeria
| | - Séverine Planchais
- Sorbonne Universités, UPMC Univ Paris 06, iEES, UMR 7618, (UPEC, UPMC, CNRS, IRD, INRA, Paris Diderot), case 237, 4 place Jussieu, F-75252, Paris cedex 05, France
| | - Cécile Cabassa
- Sorbonne Universités, UPMC Univ Paris 06, iEES, UMR 7618, (UPEC, UPMC, CNRS, IRD, INRA, Paris Diderot), case 237, 4 place Jussieu, F-75252, Paris cedex 05, France
| | - Reda Djebbar
- Laboratory of Biology and Physiology of Organisms, Faculty of Biological Sciences, Houari Boumediene University of Sciences and Technology, BP 32, El Alia 16111, Algeria
| | - Ouzna Abrous Belbachir
- Laboratory of Biology and Physiology of Organisms, Faculty of Biological Sciences, Houari Boumediene University of Sciences and Technology, BP 32, El Alia 16111, Algeria
| | - Pierre Carol
- Sorbonne Universités, UPMC Univ Paris 06, iEES, UMR 7618, (UPEC, UPMC, CNRS, IRD, INRA, Paris Diderot), case 237, 4 place Jussieu, F-75252, Paris cedex 05, France
| |
Collapse
|
28
|
Alber NA, Sivanesan H, Vanlerberghe GC. The occurrence and control of nitric oxide generation by the plant mitochondrial electron transport chain. PLANT, CELL & ENVIRONMENT 2017; 40:1074-1085. [PMID: 27987212 DOI: 10.1111/pce.12884] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 12/02/2016] [Accepted: 12/05/2016] [Indexed: 05/03/2023]
Abstract
The plant mitochondrial electron transport chain (ETC) is bifurcated such that electrons from ubiquinol are passed to oxygen via the usual cytochrome path or through alternative oxidase (AOX). We previously showed that knockdown of AOX in transgenic tobacco increased leaf concentrations of nitric oxide (NO), implying that an activity capable of generating NO had been effected. Here, we identify the potential source of this NO. Treatment of leaves with antimycin A (AA, Qi -site inhibitor of Complex III) increased NO amount more than treatment with myxothiazol (Myxo, Qo -site inhibitor) despite both being equally effective at inhibiting respiration. Comparison of nitrate-grown wild-type with AOX knockdown and overexpression plants showed a negative correlation between AOX amount and NO amount following AA. Further, Myxo fully negated the ability of AA to increase NO amount. With ammonium-grown plants, neither AA nor Myxo strongly increased NO amount in any plant line. When these leaves were supplied with nitrite alongside the AA or Myxo, then the inhibitor effects across lines mirrored that of nitrate-grown plants. Hence the ETC, likely the Q-cycle of Complex III generates NO from nitrite, and AOX reduces this activity by acting as a non-energy-conserving electron sink upstream of Complex III.
Collapse
Affiliation(s)
- Nicole A Alber
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C1A4, Canada
| | - Hampavi Sivanesan
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C1A4, Canada
| | - Greg C Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C1A4, Canada
| |
Collapse
|
29
|
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.
Collapse
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
| |
Collapse
|
30
|
Derevyanchuk M, Kretynin S, Iakovenko O, Litvinovskaya R, Zhabinskii V, Martinec J, Blume Y, Khripach V, Kravets V. Effect of 24-epibrassinolide on Brassica napus alternative respiratory pathway, guard cells movements and phospholipid signaling under salt stress. Steroids 2017; 117:16-24. [PMID: 27913097 DOI: 10.1016/j.steroids.2016.11.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 11/24/2016] [Accepted: 11/25/2016] [Indexed: 12/17/2022]
Abstract
Using Brassica napus roots we observed statistically significant increase in alternative respiratory pathway in response to exogenous 24-epibrassinolide (EBL) under optimal conditions and salinity. Also we observed activation of phospholipid signaling under the same conditions in response to EBL by measuring levels of lipid second messengers - diacylglycerol (DAG) and phosphatidic acid (PA). We found that brassinosteroids cause closure of stomata in isolated leaf disks while inhibitors of alternative oxidase cancelled these effects. This study demonstrates that BRs activate total respiration rate, alternative respiratory pathway, production of PA and DAG, stimulate stomata closure and growth under optimal conditions and salinity. Also, specific inhibitor of brassinosteroids biosynthesis decreased alternative respiratory pathway and production of lipid messengers in rape plants.
Collapse
Affiliation(s)
- Michael Derevyanchuk
- Department of the Molecular Mechanisms of Cell Metabolism Regulation, Institute of Bioorganic Chemistry and Petrochemistry, The National Academy of Sciences of Ukraine, 02660, Murmanska str., 1, Kyiv, Ukraine
| | - Sergii Kretynin
- Department of the Molecular Mechanisms of Cell Metabolism Regulation, Institute of Bioorganic Chemistry and Petrochemistry, The National Academy of Sciences of Ukraine, 02660, Murmanska str., 1, Kyiv, Ukraine
| | - Oksana Iakovenko
- Department of the Molecular Mechanisms of Cell Metabolism Regulation, Institute of Bioorganic Chemistry and Petrochemistry, The National Academy of Sciences of Ukraine, 02660, Murmanska str., 1, Kyiv, Ukraine
| | - Raisa Litvinovskaya
- Laboratory of Steroid Chemistry, Institute of Bioorganic Chemistry, The National Academy of Sciences of Belarus, 220141, Kuprevich str., 5, Minsk, Belarus
| | - Vladimir Zhabinskii
- Laboratory of Steroid Chemistry, Institute of Bioorganic Chemistry, The National Academy of Sciences of Belarus, 220141, Kuprevich str., 5, Minsk, Belarus
| | - Jan Martinec
- Department of Biology, Faculty of Sciences, Jan Evangelista Purkyne University, Usti nad Labem, Czech Republic
| | - Yaroslav Blume
- Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Osypovskogo 2a, Kyiv 04123, Ukraine
| | - Vladimir Khripach
- Laboratory of Steroid Chemistry, Institute of Bioorganic Chemistry, The National Academy of Sciences of Belarus, 220141, Kuprevich str., 5, Minsk, Belarus
| | - Volodymyr Kravets
- Department of the Molecular Mechanisms of Cell Metabolism Regulation, Institute of Bioorganic Chemistry and Petrochemistry, The National Academy of Sciences of Ukraine, 02660, Murmanska str., 1, Kyiv, Ukraine.
| |
Collapse
|
31
|
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.
Collapse
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
| |
Collapse
|
32
|
Hydrogen sulfide - cysteine cycle system enhances cadmium tolerance through alleviating cadmium-induced oxidative stress and ion toxicity in Arabidopsis roots. Sci Rep 2016; 6:39702. [PMID: 28004782 PMCID: PMC5177925 DOI: 10.1038/srep39702] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 11/25/2016] [Indexed: 11/28/2022] Open
Abstract
Cadmium (Cd2+) is a common toxic heavy metal ion. We investigated the roles of hydrogen sulfide (H2S) and cysteine (Cys) in plant responses to Cd2+ stress. The expression of H2S synthetic genes LCD and DES1 were induced by Cd2+ within 3 h, and endogenous H2S was then rapidly released. H2S promoted the expression of Cys synthesis-related genes SAT1 and OASA1, which led to endogenous Cys accumulation. The H2S and Cys cycle system was stimulated by Cd2+ stress, and it maintained high levels in plant cells. H2S inhibited the ROS burst by inducing alternative respiration capacity (AP) and antioxidase activity. H2S weakened Cd2+ toxicity by inducing the metallothionein (MTs) genes expression. Cys promoted GSH accumulation and inhibited the ROS burst, and GSH induced the expression of phytochelatin (PCs) genes, counteracting Cd2+ toxicity. In summary, the H2S and Cys cycle system played a key role in plant responses to Cd2+ stress. The Cd2+ tolerance was weakened when the cycle system was blocked in lcddes1-1 and oasa1 mutants. This paper is the first to describe the role of the H2S and Cys cycle system in Cd2+ stress and to explore the relevant and specificity mechanisms of H2S and Cys in mediating Cd2+ stress.
Collapse
|
33
|
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: 73] [Impact Index Per Article: 9.1] [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.
Collapse
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
| |
Collapse
|
34
|
Gardeström P, Igamberdiev AU. The origin of cytosolic ATP in photosynthetic cells. PHYSIOLOGIA PLANTARUM 2016; 157:367-79. [PMID: 27087668 DOI: 10.1111/ppl.12455] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 03/22/2016] [Accepted: 03/24/2016] [Indexed: 05/02/2023]
Abstract
In photosynthetically active cells, both chloroplasts and mitochondria have the capacity to produce ATP via photophosphorylation and oxidative phosphorylation, respectively. Thus, theoretically, both organelles could provide ATP for the cytosol, but the extent, to which they actually do this, and how the process is regulated, both remain unclear. Most of the evidence discussed comes from experiments with rapid fractionation of isolated protoplasts subjected to different treatments in combination with application of specific inhibitors. The results obtained indicate that, under conditions where ATP demand for photosynthetic CO2 fixation is sufficiently high, the mitochondria supply the bulk of ATP for the cytosol. In contrast, under stress conditions where CO2 fixation is severely limited, ATP will build up in chloroplasts and it can then be exported to the cytosol, by metabolite shuttle mechanisms. Thus, depending on the conditions, either mitochondria or chloroplasts can supply the bulk of ATP for the cytosol. This supply of ATP is discussed in relation to the idea that mitochondrial functions may be tuned to provide an optimal environment for the chloroplast. By balancing cellular redox states, mitochondria can contribute to an optimal photosynthetic capacity.
Collapse
Affiliation(s)
- Per Gardeström
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, Canada
| |
Collapse
|
35
|
Jian W, Zhang DW, Zhu F, Wang SX, Pu XJ, Deng XG, Luo SS, Lin HH. Alternative oxidase pathway is involved in the exogenous SNP-elevated tolerance of Medicago truncatula to salt stress. JOURNAL OF PLANT PHYSIOLOGY 2016; 193:79-87. [PMID: 26962709 DOI: 10.1016/j.jplph.2016.01.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 12/06/2015] [Accepted: 01/22/2016] [Indexed: 05/04/2023]
Abstract
Exogenous application of sodium nitroprusside (SNP) would enhance the tolerance of plants to stress conditions. Some evidences suggested that nitric oxide (NO) could induce the expression of alternative oxidase (AOX). In this study, Medicago truncatula (Medicago) was chosen to study the role of AOX in the SNP-elevated resistance to salt stress. Our results showed that the expression of AOX genes (especially AOX1 and AOX2b1) and cyanide-resistant respiration rate (Valt) could be significantly induced by salt stress. Exogenous application of SNP could further enhance the expression of AOX genes and Valt. Exogenous application of SNP could alleviate the oxidative damage and photosynthetic damage caused by salt stress. However, the stress resistance was significantly decreased in the plants which were pretreated with n-propyl gallate (nPG). More importantly, the damage in nPG-pretreated plants could not be alleviated by application of SNP. Further study showed that effects of nPG on the activities of antioxidant enzymes were minor. These results showed that AOX pathway played an important role in the SNP-elevated resistance of Medicago to salt stress. AOX could contribute to regulating the accumulation of reactive oxygen (ROS) and protect of photosystem, and we proposed that all these were depend on the ability of maintaining the homeostasis of redox state.
Collapse
Affiliation(s)
- Wei Jian
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Da-wei Zhang
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Feng Zhu
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Shuo-xun Wang
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Xiao-jun Pu
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Xing-guang Deng
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Shi-shuai Luo
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China
| | - Hong-hui Lin
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, State Key Laboratory of Hydraulics and Mountain River Engineering, Chengdu 610064, China.
| |
Collapse
|
36
|
Garcia L, Welchen E, Gey U, Arce AL, Steinebrunner I, Gonzalez DH. The cytochrome c oxidase biogenesis factor AtCOX17 modulates stress responses in Arabidopsis. PLANT, CELL & ENVIRONMENT 2016; 39:628-44. [PMID: 26436309 DOI: 10.1111/pce.12647] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/22/2015] [Indexed: 05/03/2023]
Abstract
COX17 is a soluble protein from the mitochondrial intermembrane space that participates in the transfer of copper for cytochrome c oxidase (COX) assembly in eukaryotic organisms. In this work, we studied the function of both Arabidopsis thaliana AtCOX17 genes using plants with altered expression levels of these genes. Silencing of AtCOX17-1 in a cox17-2 knockout background generates plants with smaller rosettes and decreased expression of genes involved in the response of plants to different stress conditions, including several genes that are induced by mitochondrial dysfunctions. Silencing of either of the AtCOX17 genes does not affect plant development or COX activity but causes a decrease in the response of genes to salt stress. In addition, these plants contain higher reactive oxygen and lipid peroxidation levels after irrigation with high NaCl concentrations and are less sensitive to abscisic acid. In agreement with a role of AtCOX17 in stress and abscisic acid responses, both AtCOX17 genes are induced by several stress conditions, abscisic acid and mutation of the transcription factor ABI4. The results indicate that AtCOX17 is required for optimal expression of a group of stress-responsive genes, probably as a component of signalling pathways that link stress conditions to gene expression responses.
Collapse
Affiliation(s)
- Lucila Garcia
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Elina Welchen
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Uta Gey
- Technische Universität Dresden, Department of Biology, 01062, Dresden, Germany
| | - Agustín L Arce
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Iris Steinebrunner
- Technische Universität Dresden, Department of Biology, 01062, Dresden, Germany
| | - Daniel H Gonzalez
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| |
Collapse
|
37
|
Arnholdt-Schmitt B, Ragonezi C, Cardoso H. Do Mitochondria Play a Central Role in Stress-Induced Somatic Embryogenesis? Methods Mol Biol 2016; 1359:87-100. [PMID: 26619859 DOI: 10.1007/978-1-4939-3061-6_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This review highlights a four-step rational for the hypothesis that mitochondria play an upstream central role for stress-induced somatic embryogenesis (SE): (1) Initiation of SE is linked to programmed cell death (PCD) (2) Mitochondria are crucially connected to cell death (3) SE is challenged by stress per se (4) Mitochondria are centrally linked to plant stress response and its management. Additionally the review provides a rough perspective for the use of mitochondrial-derived functional marker (FM) candidates to improve SE efficiency. It is proposed to apply SE systems as phenotyping tool for identifying superior genotypes with high general plasticity under severe plant stress conditions.
Collapse
Affiliation(s)
- Birgit Arnholdt-Schmitt
- EU Marie Curie Chair, ICAAM, IIFA, Universidade de Évora, Núcleo da Mitra, Ap. 94, Évora, 7002-554, Portugal.
| | - Carla Ragonezi
- EU Marie Curie Chair, ICAAM, IIFA, Universidade de Évora, Núcleo da Mitra, Ap. 94, Évora, 7002-554, Portugal
| | - Hélia Cardoso
- EU Marie Curie Chair, ICAAM, IIFA, Universidade de Évora, Núcleo da Mitra, Ap. 94, Évora, 7002-554, Portugal
| |
Collapse
|
38
|
Dahal K, Martyn GD, Vanlerberghe GC. Improved photosynthetic performance during severe drought in Nicotiana tabacum overexpressing a nonenergy conserving respiratory electron sink. THE NEW PHYTOLOGIST 2015; 208:382-95. [PMID: 26032897 DOI: 10.1111/nph.13479] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 04/23/2015] [Indexed: 05/02/2023]
Abstract
Chloroplasts have means to manage excess reducing power but these mechanisms may become restricted by rates of ATP turnover. Alternative oxidase (AOX) is a mitochondrial terminal oxidase that uncouples the consumption of reducing power from ATP synthesis. Physiological and biochemical analyses were used to compare respiration and photosynthesis of Nicotiana tabacum wild-type (WT) plants with that of transgenic lines overexpressing AOX, under both well-watered and drought stress conditions. With increasing drought severity, AOX overexpression acted to increase respiration in the light (RL ) relative to WT. CO2 and light response curves indicated that overexpression also improved photosynthetic performance relative to WT, as drought severity increased. This was not due to an effect of AOX amount on leaf water status or the development of the diffusive limitations that occur due to drought. Rather, AOX overexpression dampened photosystem stoichiometry adjustments and losses of key photosynthetic components that occurred in WT. The results indicate that AOX amount influences RL , particularly during severe drought, when cytochrome pathway respiration may become increasingly restricted. This impacts the chloroplast redox state, influencing how the photosynthetic apparatus responds to increasing drought severity. In particular, the development of biochemical limitations to photosynthesis are dampened in plants with increased nonenergy conserving RL .
Collapse
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 D Martyn
- 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
| |
Collapse
|
39
|
Rogov AG, Sukhanova EI, Uralskaya LA, Aliverdieva DA, Zvyagilskaya RA. Alternative oxidase: distribution, induction, properties, structure, regulation, and functions. BIOCHEMISTRY (MOSCOW) 2015; 79:1615-34. [PMID: 25749168 DOI: 10.1134/s0006297914130112] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The respiratory chain in the majority of organisms with aerobic type metabolism features the concomitant existence of the phosphorylating cytochrome pathway and the cyanide- and antimycin A-insensitive oxidative route comprising a so-called alternative oxidase (AOX) as a terminal oxidase. In this review, the history of AOX discovery is described. Considerable evidence is presented that AOX occurs widely in organisms at various levels of organization and is not confined to the plant kingdom. This enzyme has not been found only in Archaea, mammals, some yeasts and protists. Bioinformatics research revealed the sequences characteristic of AOX in representatives of various taxonomic groups. Based on multiple alignments of these sequences, a phylogenetic tree was constructed to infer their possible evolution. The ways of AOX activation, as well as regulatory interactions between AOX and the main respiratory chain are described. Data are summarized concerning the properties of AOX and the AOX-encoding genes whose expression is either constitutive or induced by various factors. Information is presented on the structure of AOX, its active center, and the ubiquinone-binding site. The principal functions of AOX are analyzed, including the cases of cell survival, optimization of respiratory metabolism, protection against excess of reactive oxygen species, and adaptation to variable nutrition sources and to biotic and abiotic stress factors. It is emphasized that different AOX functions complement each other in many instances and are not mutually exclusive. Examples are given to demonstrate that AOX is an important tool to overcome the adverse aftereffects of restricted activity of the main respiratory chain in cells and whole animals. This is the first comprehensive review on alternative oxidases of various organisms ranging from yeasts and protists to vascular plants.
Collapse
Affiliation(s)
- A G Rogov
- Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
| | | | | | | | | |
Collapse
|
40
|
Derevyanchuk MV, Grabelnyh OI, Litvinovskaya RP, Voinikov VK, Sauchuk AL, Khripach VA, Kravets VS. Influence of brassinosteroids on plant cell alternative respiration pathway and antioxidant systems activity under abiotic stress conditions. ACTA ACUST UNITED AC 2014. [DOI: 10.7124/bc.0008bd] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | - O. I. Grabelnyh
- Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch of the Russian Academy of Sciences
| | | | - V. K. Voinikov
- Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch of the Russian Academy of Sciences
| | | | | | - V. S. Kravets
- Institute of Bioorganic Chemistry and Petrochemistry, NAS of Ukraine
| |
Collapse
|
41
|
Dahal K, Wang J, Martyn GD, Rahimy F, Vanlerberghe GC. Mitochondrial alternative oxidase maintains respiration and preserves photosynthetic capacity during moderate drought in Nicotiana tabacum. PLANT PHYSIOLOGY 2014; 166:1560-74. [PMID: 25204647 PMCID: PMC4226348 DOI: 10.1104/pp.114.247866] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 09/07/2014] [Indexed: 05/18/2023]
Abstract
The mitochondrial electron transport chain includes an alternative oxidase (AOX) that is hypothesized to aid photosynthetic metabolism, perhaps by acting as an additional electron sink for photogenerated reductant or by dampening the generation of reactive oxygen species. Gas exchange, chlorophyll fluorescence, photosystem I (PSI) absorbance, and biochemical and protein analyses were used to compare respiration and photosynthesis of Nicotiana tabacum 'Petit Havana SR1' wild-type plants with that of transgenic AOX knockdown (RNA interference) and overexpression lines, under both well-watered and moderate drought-stressed conditions. During drought, AOX knockdown lines displayed a lower rate of respiration in the light than the wild type, as confirmed by two independent methods. Furthermore, CO2 and light response curves indicated a nonstomatal limitation of photosynthesis in the knockdowns during drought, relative to the wild type. Also relative to the wild type, the knockdowns under drought maintained PSI and PSII in a more reduced redox state, showed greater regulated nonphotochemical energy quenching by PSII, and displayed a higher relative rate of cyclic electron transport around PSI. The origin of these differences may lie in the chloroplast ATP synthase amount, which declined dramatically in the knockdowns in response to drought. None of these effects were seen in plants overexpressing AOX. The results show that AOX is necessary to maintain mitochondrial respiration during moderate drought. In its absence, respiration rate slows and the lack of this electron sink feeds back on the photosynthetic apparatus, resulting in a loss of chloroplast ATP synthase that then limits photosynthetic capacity.
Collapse
Affiliation(s)
- Keshav Dahal
- Departments of Biological Sciences and Cell and Systems Biology, University of Toronto, Scarborough, Toronto, Ontario, Canada M1C1A4
| | - Jia Wang
- Departments of Biological Sciences and Cell and Systems Biology, University of Toronto, Scarborough, Toronto, Ontario, Canada M1C1A4
| | - Greg D Martyn
- Departments of Biological Sciences and Cell and Systems Biology, University of Toronto, Scarborough, Toronto, Ontario, Canada M1C1A4
| | - Farkhunda Rahimy
- Departments of Biological Sciences and Cell and Systems Biology, University of Toronto, Scarborough, Toronto, Ontario, Canada M1C1A4
| | - Greg C Vanlerberghe
- Departments of Biological Sciences and Cell and Systems Biology, University of Toronto, Scarborough, Toronto, Ontario, Canada M1C1A4
| |
Collapse
|
42
|
Cvetkovska M, Dahal K, Alber NA, Jin C, Cheung M, Vanlerberghe GC. Knockdown of mitochondrial alternative oxidase induces the 'stress state' of signaling molecule pools in Nicotiana tabacum, with implications for stomatal function. THE NEW PHYTOLOGIST 2014; 203:449-461. [PMID: 24635054 DOI: 10.1111/nph.12773] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 02/19/2014] [Indexed: 05/18/2023]
Abstract
The mitochondrial electron transport chain (ETC) includes an alternative oxidase (AOX) that may control the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). ROS and RNS act as signaling intermediates in numerous plant processes, including stomatal movement. The role of AOX in controlling ROS and RNS concentrations under both steady-state and different stress conditions was evaluated using Nicotiana tabacum plants lacking AOX as a result of RNA interference. A potential functional implication of changes in ROS and RNS homeostasis was also evaluated by examining stomatal function. The leaves of nonstressed AOX knockdowns maintained concentrations of H2O2 and nitric oxide (NO) normally seen in wildtype plants only under stress conditions. Further, guard cell NO amounts were much higher in knockdowns. These guard cells were altered in size and were less responsive to NO as a signal for stomatal closure. This, in turn, compromised the stomatal response to changing irradiance. The results reveal a role for AOX in stomata. A working model is that guard cell AOX respiration maintains NO homeostasis by preventing over-reduction of the ETC, particularly during periods when high concentrations of NO acting as a signal for stomatal closure may also be inhibiting cyt oxidase respiration.
Collapse
Affiliation(s)
- Marina Cvetkovska
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Keshav Dahal
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Nicole A Alber
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Cathy Jin
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Melissa Cheung
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Greg C Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| |
Collapse
|
43
|
Noctor G, Mhamdi A, Foyer CH. The roles of reactive oxygen metabolism in drought: not so cut and dried. PLANT PHYSIOLOGY 2014; 164:1636-48. [PMID: 24715539 PMCID: PMC3982730 DOI: 10.1104/pp.113.233478] [Citation(s) in RCA: 289] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 03/05/2014] [Indexed: 05/18/2023]
Abstract
Drought is considered to cause oxidative stress, but the roles of oxidant-induced modifications in plant responses to water deficit remain obscure. Key unknowns are the roles of reactive oxygen species (ROS) produced at specific intracellular or apoplastic sites and the interactions between the complex, networking antioxidative systems in restricting ROS accumulation or in redox signal transmission. This Update discusses the physiological aspects of ROS production during drought, and analyzes the relationship between oxidative stress and drought from different but complementary perspectives. We ask to what extent redox changes are involved in plant drought responses and discuss the roles that different ROS-generating processes may play. Our discussion emphasizes the complexity and the specificity of antioxidant systems, and the likely importance of thiol systems in drought-induced redox signaling. We identify candidate drought-responsive redox-associated genes and analyze the potential importance of different metabolic pathways in drought-associated oxidative stress signaling.
Collapse
Affiliation(s)
| | - Amna Mhamdi
- Institut de Biologie des Plantes, Unité Mixte de Recherche 8618 Centre National de la Recherche Scientifique, Université de Paris-Sud, 91405 Orsay cedex, France (G.N., A.M.); and
- Centre for Plant Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom (C.H.F.)
| | - Christine H. Foyer
- Institut de Biologie des Plantes, Unité Mixte de Recherche 8618 Centre National de la Recherche Scientifique, Université de Paris-Sud, 91405 Orsay cedex, France (G.N., A.M.); and
- Centre for Plant Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom (C.H.F.)
| |
Collapse
|
44
|
Feng H, Guan D, Sun K, Wang Y, Zhang T, Wang R. Expression and signal regulation of the alternative oxidase genes under abiotic stresses. Acta Biochim Biophys Sin (Shanghai) 2013; 45:985-94. [PMID: 24004533 DOI: 10.1093/abbs/gmt094] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Plants in their natural environment frequently face various abiotic stresses, such as drought, high salinity, and chilling. Plant mitochondria contain an alternative oxidase (AOX), which is encoded by a small family of nuclear genes. AOX genes have been shown to be highly responsive to abiotic stresses. Using transgenic plants with varying levels of AOX expression, it has been confirmed that AOX genes are important for abiotic stress tolerance. Although the roles of AOX under abiotic stresses have been extensively studied and there are several excellent reviews on this topic, the differential expression patterns of the AOX gene family members and the signal regulation of AOX gene(s) under abiotic stresses have not been extensively summarized. Here, we review and discuss the current progress of these two important issues.
Collapse
Affiliation(s)
- Hanqing Feng
- College of Life Science, Northwest Normal University, Lanzhou 730070, China
| | | | | | | | | | | |
Collapse
|