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Hill RD, Igamberdiev AU, Stasolla C. Preserving root stem cell functionality under low oxygen stress: the role of nitric oxide and phytoglobins. PLANTA 2023; 258:89. [PMID: 37759033 DOI: 10.1007/s00425-023-04246-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023]
Abstract
MAIN CONCLUSION The preservation of quiescent center stem cell integrity in hypoxic roots by phytoglobins is exercised through their ability to scavenge nitric oxide and attenuate its effects on auxin transport and cell degradation. Under low oxygen stress, the retention or induction of phytoglobin expression maintains cell viability while loss or lack of induction of phytoglobin leads to cell degradation. Plants have evolved unique attributes to ensure survival in the environment in which they must exist. Common among the attributes is the ability to maintain stem cells in a quiescent (or low proliferation) state in unfriendly environments. From the seed embryo to meristematic regions of the plant, quiescent stem cells exist to regenerate the organism when environmental conditions are suitable to allow plant survival. Frequently, plants dispose of mature cells or organs in the process of acclimating to the stresses to ensure survival of meristems, the stem cells of which are capable of regenerating cells and organs that have been sacrificed, a feature not generally available to mammals. Most of the research on plant stress responses has dealt with how mature cells respond because of the difficulty of specifically examining plant meristem responses to stress. This raises the question as to whether quiescent stem cells behave in a similar fashion to mature cells in their response to stress and what factors within these critical cells determine whether they survive or degrade when exposed to environmental stress. This review attempts to examine this question with respect to the quiescent center (QC) stem cells of the root apical meristem. Emphasis is put on how varying levels of nitric oxide, influenced by the expression of phytoglobins, affect QC response to hypoxic stress.
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Affiliation(s)
- Robert D Hill
- Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Claudio Stasolla
- Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.
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2
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Komatsu S, Hamada K, Furuya T, Nishiuchi T, Tani M. Membrane Proteomics to Understand Enhancement Effects of Millimeter-Wave Irradiation on Wheat Root under Flooding Stress. Int J Mol Sci 2023; 24:ijms24109014. [PMID: 37240359 DOI: 10.3390/ijms24109014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/13/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
Millimeter-wave irradiation of wheat seeds enhances the growth of roots under flooding stress, but its mechanism is not clearly understood. To understand the role of millimeter-wave irradiation on root-growth enhancement, membrane proteomics was performed. Membrane fractions purified from wheat roots were evaluated for purity. H+-ATPase and calnexin, which are protein markers for membrane-purification efficiency, were enriched in a membrane fraction. A principal-component analysis of the proteomic results indicated that the millimeter-wave irradiation of seeds affects membrane proteins in grown roots. Proteins identified using proteomic analysis were confirmed using immunoblot or polymerase chain reaction analyses. The abundance of cellulose synthetase, which is a plasma-membrane protein, decreased under flooding stress; however, it increased with millimeter-wave irradiation. On the other hand, the abundance of calnexin and V-ATPase, which are proteins in the endoplasmic reticulum and vacuolar, increased under flooding stress; however, it decreased with millimeter-wave irradiation. Furthermore, NADH dehydrogenase, which is found in mitochondria membranes, was upregulated due to flooding stress but downregulated following millimeter-wave irradiation even under flooding stress. The ATP content showed a similar trend toward change in NADH dehydrogenase expression. These results suggest that millimeter-wave irradiation improves the root growth of wheat via the transitions of proteins in the plasma membrane, endoplasmic reticulum, vacuolar, and mitochondria.
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Affiliation(s)
- Setsuko Komatsu
- Faculty of Environment and Information Sciences, Fukui University of Technology, Fukui 910-8505, Japan
| | - Kazuna Hamada
- Faculty of Environment and Information Sciences, Fukui University of Technology, Fukui 910-8505, Japan
| | - Takashi Furuya
- Research Center for Development of Far-Infrared Region, University of Fukui, Fukui 910-8507, Japan
| | - Takumi Nishiuchi
- Institute for Gene Research, Kanazawa University, Kanazawa 920-8640, Japan
| | - Masahiko Tani
- Research Center for Development of Far-Infrared Region, University of Fukui, Fukui 910-8507, Japan
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3
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Xie J, Wang W, Yang T, Zhang Q, Zhang Z, Zhu X, Li N, Zhi L, Ma X, Zhang S, Liu Y, Wang X, Li F, Zhao Y, Jia X, Zhou J, Jiang N, Li G, Liu M, Liu S, Li L, Zeng A, Du M, Zhang Z, Li J, Zhang Z, Li Z, Zhang H. Large-scale genomic and transcriptomic profiles of rice hybrids reveal a core mechanism underlying heterosis. Genome Biol 2022; 23:264. [PMID: 36550554 PMCID: PMC9773586 DOI: 10.1186/s13059-022-02822-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Heterosis is widely used in agriculture. However, its molecular mechanisms are still unclear in plants. Here, we develop, sequence, and record the phenotypes of 418 hybrids from crosses between two testers and 265 rice varieties from a mini-core collection. RESULTS Phenotypic analysis shows that heterosis is dependent on genetic backgrounds and environments. By genome-wide association study of 418 hybrids and their parents, we find that nonadditive QTLs are the main genetic contributors to heterosis. We show that nonadditive QTLs are more sensitive to the genetic background and environment than additive ones. Further simulations and experimental analysis support a novel mechanism, homo-insufficiency under insufficient background (HoIIB), underlying heterosis. We propose heterosis in most cases is not due to heterozygote advantage but homozygote disadvantage under the insufficient genetic background. CONCLUSION The HoIIB model elucidates that genetic background insufficiency is the intrinsic mechanism of background dependence, and also the core mechanism of nonadditive effects and heterosis. This model can explain most known hypotheses and phenomena about heterosis, and thus provides a novel theory for hybrid rice breeding in future.
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Affiliation(s)
- Jianyin Xie
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Weiping Wang
- grid.496830.00000 0004 7648 0514State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, 410125 China
| | - Tao Yang
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Quan Zhang
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Zhifang Zhang
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Xiaoyang Zhu
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Ni Li
- grid.496830.00000 0004 7648 0514State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, 410125 China
| | - Linran Zhi
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Xiaoqian Ma
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Shuyang Zhang
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Yan Liu
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Xueqiang Wang
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Fengmei Li
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China ,grid.428986.90000 0001 0373 6302Sanya Nanfan Research Institute of Hainan University, Sanya, 572024 China
| | - Yan Zhao
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Xuewei Jia
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Jieyu Zhou
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Ningjia Jiang
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China ,Sanya Institute of China Agricultural University, Sanya, 572024 China
| | - Gangling Li
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Miaosong Liu
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Shijin Liu
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Lin Li
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - An Zeng
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China ,grid.428986.90000 0001 0373 6302Sanya Nanfan Research Institute of Hainan University, Sanya, 572024 China ,Sanya Institute of China Agricultural University, Sanya, 572024 China
| | - Mengke Du
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China ,grid.428986.90000 0001 0373 6302Sanya Nanfan Research Institute of Hainan University, Sanya, 572024 China
| | - Zhanying Zhang
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Jinjie Li
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China
| | - Ziding Zhang
- grid.22935.3f0000 0004 0530 8290State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing, 100193 China
| | - Zichao Li
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China ,Sanya Institute of China Agricultural University, Sanya, 572024 China ,grid.22935.3f0000 0004 0530 8290State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing, 100193 China
| | - Hongliang Zhang
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Crop Heterosis and Utilization, the Ministry of Education / Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193 China ,grid.428986.90000 0001 0373 6302Sanya Nanfan Research Institute of Hainan University, Sanya, 572024 China ,Sanya Institute of China Agricultural University, Sanya, 572024 China
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4
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Meyer EH, Letts JA, Maldonado M. Structural insights into the assembly and the function of the plant oxidative phosphorylation system. THE NEW PHYTOLOGIST 2022; 235:1315-1329. [PMID: 35588181 DOI: 10.1111/nph.18259] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 05/05/2022] [Indexed: 05/23/2023]
Abstract
One of the key functions of mitochondria is the production of ATP to support cellular metabolism and growth. The last step of mitochondrial ATP synthesis is performed by the oxidative phosphorylation (OXPHOS) system, an ensemble of protein complexes embedded in the inner mitochondrial membrane. In the last 25 yr, many structures of OXPHOS complexes and supercomplexes have been resolved in yeast, mammals, and bacteria. However, structures of plant OXPHOS enzymes only became available very recently. In this review, we highlight the plant-specific features revealed by the recent structures and discuss how they advance our understanding of the function and assembly of plant OXPHOS complexes. We also propose new hypotheses to be tested and discuss older findings to be re-evaluated. Further biochemical and structural work on the plant OXPHOS system will lead to a deeper understanding of plant respiration and its regulation, with significant agricultural, environmental, and societal implications.
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Affiliation(s)
- Etienne H Meyer
- Institute of Plant Physiology, Martin-Luther-University Halle-Wittenberg, Weinbergweg 10, 06120, Halle (Saale), Germany
| | - James A Letts
- Department of Molecular and Cellular Biology, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Maria Maldonado
- Department of Molecular and Cellular Biology, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA
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5
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Measuring the Mitochondrial Ubiquinone (Q) Pool Redox State in Isolated Respiring Mitochondria. Methods Mol Biol 2022; 2497:291-299. [PMID: 35771450 DOI: 10.1007/978-1-0716-2309-1_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The ubiquinone (Q) pool represents a node in the mitochondrial electron transport chain (ETC) onto which the electrons of all respiratory dehydrogenases converge. The redox state of the Q pool correlates closely with the electron flux through the ETC and is thus a parameter of great metabolic value for both the mitochondrial and cellular metabolism. Here, we describe the simultaneous measurement of respiratory rates of isolated mouse heart mitochondria and the redox state of their Q pool using a custom-made combination of a Clark-type oxygen electrode and a Q electrode.
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6
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Finger-Teixeira A, Ishii-Iwamoto EL, Marchiosi R, Coelho ÉMP, Constantin RP, Dos Santos WD, Soares AR, Ferrarese-Filho O. Cadmium uncouples mitochondrial oxidative phosphorylation and induces oxidative cellular stress in soybean roots. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:67711-67723. [PMID: 34263402 DOI: 10.1007/s11356-021-15368-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
Cadmium (Cd) inhibits soybean root growth, but its exact mode of action is still not completely understood. We evaluated the effects of Cd on growth, mitochondrial respiration, lipid peroxidation, total phenols, glutathione, and activities of lipoxygenase (LOX), superoxide dismutase (SOD), and catalase (CAT) in soybean roots. In primary roots, Cd stimulated KCN-insensitive respiration and KCN-SHAM-insensitive respiration, indicating the involvement of the alternative oxidase (AOX) pathway, while it decreased KCN-sensitive respiration, suggesting an inhibition of the cytochrome oxidase pathway (COX). In isolated mitochondria, Cd uncoupled the oxidative phosphorylation since it decreased state III respiration (coupled respiration) and ADP/O and respiratory control ratios, while it increased state IV respiration (depletion of exogenously added ADP). The uncoupling effect increased extramitochondrial LOX activity, lipid peroxidation, and oxidized and reduced glutathione, which induced an antioxidant response with enhanced SOD and CAT activities. In brief, our findings reveal that Cd acts as an uncoupler of the mitochondrial oxidative phosphorylation in soybean roots, disturbing cellular respiration and inducing oxidative cellular stress.
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Affiliation(s)
- Aline Finger-Teixeira
- Laboratory of Plant Biochemistry, Department of Biochemistry, University of Maringá, Maringá, PR, 87020-900, Brazil
| | - Emy Luiza Ishii-Iwamoto
- Laboratory of Biological Oxidations, Department of Biochemistry, University of Maringá, Maringá, PR, 87020-900, Brazil
| | - Rogério Marchiosi
- Laboratory of Plant Biochemistry, Department of Biochemistry, University of Maringá, Maringá, PR, 87020-900, Brazil
| | - Érica Marusa Pergo Coelho
- Laboratory of Biochemistry, Department of Agronomic Sciences, University of Maringá, Umuarama, PR, 87500-000, Brazil
| | - Rodrigo Polimeni Constantin
- Laboratory of Biological Oxidations, Department of Biochemistry, University of Maringá, Maringá, PR, 87020-900, Brazil
| | - Wanderley Dantas Dos Santos
- Laboratory of Plant Biochemistry, Department of Biochemistry, University of Maringá, Maringá, PR, 87020-900, Brazil
| | - Anderson Ricardo Soares
- Laboratory of Plant Biochemistry, Department of Biochemistry, University of Maringá, Maringá, PR, 87020-900, Brazil
| | - Osvaldo Ferrarese-Filho
- Laboratory of Plant Biochemistry, Department of Biochemistry, University of Maringá, Maringá, PR, 87020-900, Brazil.
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7
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Degradation of mitochondrial alternative oxidase in the appendices of Arum maculatum. Biochem J 2021; 477:3417-3431. [PMID: 32856714 PMCID: PMC7505559 DOI: 10.1042/bcj20200515] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 01/09/2023]
Abstract
Cyanide-resistant alternative oxidase (AOX) is a nuclear-encoded quinol oxidase located in the inner mitochondrial membrane. Although the quality control of AOX proteins is expected to have a role in elevated respiration in mitochondria, it remains unclear whether thermogenic plants possess molecular mechanisms for the mitochondrial degradation of AOX. To better understand the mechanism of AOX turnover in mitochondria, we performed a series of in organello AOX degradation assays using mitochondria from various stages of the appendices of Arum maculatum. Our analyses clearly indicated that AOX proteins at certain stages in the appendices are degraded at 30°C, which is close to the maximum appendix temperature observed during thermogenesis. Interestingly, such temperature-dependent protease activities were specifically inhibited by E-64, a cysteine protease inhibitor. Moreover, purification and subsequent nano LC–MS/MS analyses of E-64-sensitive and DCG-04-labeled active mitochondrial protease revealed an ∼30 kDa protein with an identical partial peptide sequence to the cysteine protease 1-like protein from Phoenix dactylifera. Our data collectively suggest that AOX is a potential target for temperature-dependent E-64-sensitive cysteine protease in the appendices of A. maculatum. A possible retrograde signalling cascade mediated by specific degradation of AOX proteins and its physiological significance are discussed.
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8
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Granados-Arvizu JA, Canizal-García M, Madrigal-Pérez LA, González-Hernández JC, Regalado-González C. Inhibition of alternative respiration system of Scheffersomyces stipitis and effect on glucose or xylose fermentation. FEMS Yeast Res 2021; 21:6119908. [PMID: 33493281 DOI: 10.1093/femsyr/foab005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 01/22/2021] [Indexed: 11/13/2022] Open
Abstract
Scheffersomyces stipitis is a Crabtree-negative pentose fermenting yeast, which shows a complex respiratory system involving a cytochrome and an alternative salicylhydroxamic acid (SHAM)-sensitive respiration mechanism that is poorly understood. This work aimed to investigate the role of the antimycin A (AA) sensitive respiration and SHAM-sensitive respiration in the metabolism of xylose and glucose by S. stipitis, upon different agitation conditions. Inhibition of the SHAM-sensitive respiration caused a significant (P < 0.05) decrease in glycolytic flux and oxygen consumption when using glucose and xylose under agitation conditions, but without agitation, only a mild reduction was observed. The combination of SHAM and AA abolished respiration, depleting the glycolytic flux using both carbon sources tested, leading to increased ethanol production of 21.05 g/L at 250 rpm for 0.5 M glucose, and 8.3 g/L ethanol using xylose. In contrast, inhibition of only the AA-sensitive respiration, caused increased ethanol production to 30 g/L using 0.5 M glucose at 250 rpm, and 11.3 g/L from 0.5 M xylose without agitation. Results showed that ethanol production can be induced by respiration inhibition, but the active role of SHAM-sensitive respiration should be considered to investigate better conditions to increase and optimize yields.
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Affiliation(s)
- J A Granados-Arvizu
- DIPA, PROPAC. Facultad de Química, Universidad Autónoma de Querétaro, C.U. Cerro de las Campanas s/n. Col. Las Campanas, C.P. 76010 Querétaro, Qro., México
| | - M Canizal-García
- Laboratorio de Biotecnología Microbiana, Tecnológico Nacional de México/ Instituto Tecnológico Superior de Ciudad Hidalgo, Av. Ing Carlos Rojas Gutiérrez #2120, 61100 Ciudad Hidalgo, Michoacán, México
| | - L A Madrigal-Pérez
- Laboratorio de Biotecnología Microbiana, Tecnológico Nacional de México/ Instituto Tecnológico Superior de Ciudad Hidalgo, Av. Ing Carlos Rojas Gutiérrez #2120, 61100 Ciudad Hidalgo, Michoacán, México
| | - J C González-Hernández
- Laboratorio de Bioquímica, Tecnológico Nacional de México/ Instituto Tecnológico de Morelia, Av. Tecnológico de Morelia #1500, 58120 Morelia, Michoacán, México
| | - C Regalado-González
- DIPA, PROPAC. Facultad de Química, Universidad Autónoma de Querétaro, C.U. Cerro de las Campanas s/n. Col. Las Campanas, C.P. 76010 Querétaro, Qro., México
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9
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Sweetman C, Miller TK, Booth NJ, Shavrukov Y, Jenkins CL, Soole KL, Day DA. Identification of Alternative Mitochondrial Electron Transport Pathway Components in Chickpea Indicates a Differential Response to Salinity Stress between Cultivars. Int J Mol Sci 2020; 21:E3844. [PMID: 32481694 PMCID: PMC7312301 DOI: 10.3390/ijms21113844] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 11/16/2022] Open
Abstract
All plants contain an alternative electron transport pathway (AP) in their mitochondria, consisting of the alternative oxidase (AOX) and type 2 NAD(P)H dehydrogenase (ND) families, that are thought to play a role in controlling oxidative stress responses at the cellular level. These alternative electron transport components have been extensively studied in plants like Arabidopsis and stress inducible isoforms identified, but we know very little about them in the important crop plant chickpea. Here we identify AP components in chickpea (Cicer arietinum) and explore their response to stress at the transcript level. Based on sequence similarity with the functionally characterized proteins of Arabidopsis thaliana, five putative internal (matrix)-facing NAD(P)H dehydrogenases (CaNDA1-4 and CaNDC1) and four putative external (inter-membrane space)-facing NAD(P)H dehydrogenases (CaNDB1-4) were identified in chickpea. The corresponding activities were demonstrated for the first time in purified mitochondria of chickpea leaves and roots. Oxidation of matrix NADH generated from malate or glycine in the presence of the Complex I inhibitor rotenone was high compared to other plant species, as was oxidation of exogenous NAD(P)H. In leaf mitochondria, external NADH oxidation was stimulated by exogenous calcium and external NADPH oxidation was essentially calcium dependent. However, in roots these activities were low and largely calcium independent. A salinity experiment with six chickpea cultivars was used to identify salt-responsive alternative oxidase and NAD(P)H dehydrogenase gene transcripts in leaves from a three-point time series. An analysis of the Na:K ratio and Na content separated these cultivars into high and low Na accumulators. In the high Na accumulators, there was a significant up-regulation of CaAOX1, CaNDB2, CaNDB4, CaNDA3 and CaNDC1 in leaf tissue under long term stress, suggesting the formation of a stress-modified form of the mitochondrial electron transport chain (mETC) in leaves of these cultivars. In particular, stress-induced expression of the CaNDB2 gene showed a striking positive correlation with that of CaAOX1 across all genotypes and time points. The coordinated salinity-induced up-regulation of CaAOX1 and CaNDB2 suggests that the mitochondrial alternative pathway of respiration is an important facet of the stress response in chickpea, in high Na accumulators in particular, despite high capacities for both of these activities in leaf mitochondria of non-stressed chickpeas.
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Affiliation(s)
- Crystal Sweetman
- College of Science & Engineering, Flinders University, GPO Box 5100, Adelaide SA 5001, Australia; (T.K.M.); (N.J.B.); (Y.S.); (C.L.D.J.); (K.L.S.); (D.A.D.)
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10
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Yu LL, Liu Y, Liu CJ, Zhu F, He ZQ, Xu F. Overexpressed β-cyanoalanine synthase functions with alternative oxidase to improve tobacco resistance to salt stress by alleviating oxidative damage. FEBS Lett 2020; 594:1284-1295. [PMID: 31858584 DOI: 10.1002/1873-3468.13723] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 12/03/2019] [Accepted: 12/05/2019] [Indexed: 11/09/2022]
Abstract
β-Cyanoalanine synthase (β-CAS) is an enzyme involved in cyanide detoxification. However, little information is available regarding the effects of β-CAS activity changes on plant resistance to environmental stress. Here, we found that β-CAS overexpression (CAS-OE) improves the resistance of tobacco plants to salt stress, whereas plants with β-CAS silencing suffer more oxidative damage than wild-type plants. Notably, blocking respiration by the alternative oxidase (AOX) pathway significantly aggravates stress injury and impairs the salt stress tolerance mediated by CAS-OE. These findings present novel insights into the synergistic effect between β-CAS and AOX in protecting plants from salt stress, where β-CAS plays a vital role in restraining cyanide accumulation, and AOX helps to alleviate the toxic effect of cyanide.
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Affiliation(s)
- Lu-Lu Yu
- Applied Biotechnology Center, Wuhan University of Bioengineering, China
| | - Yang Liu
- Applied Biotechnology Center, Wuhan University of Bioengineering, China
| | - Cui-Jiao Liu
- Applied Biotechnology Center, Wuhan University of Bioengineering, China
| | - Feng Zhu
- College of Horticulture and Plant Protection, Yangzhou University, China
| | - Zheng-Quan He
- The Key Laboratory of Plant Genetics Development and Germplasm Innovation in the Three Gorges Region, Biotechnology Research Center, China Three Gorges University, Yichang, China
| | - Fei Xu
- Applied Biotechnology Center, Wuhan University of Bioengineering, China
- The Key Laboratory of Plant Genetics Development and Germplasm Innovation in the Three Gorges Region, Biotechnology Research Center, China Three Gorges University, Yichang, China
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11
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Bioenergetic consequences from xenotopic expression of a tunicate AOX in mouse mitochondria: Switch from RET and ROS to FET. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2020; 1861:148137. [PMID: 31825809 DOI: 10.1016/j.bbabio.2019.148137] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 12/01/2019] [Accepted: 12/05/2019] [Indexed: 12/23/2022]
Abstract
Electron transfer from all respiratory chain dehydrogenases of the electron transport chain (ETC) converges at the level of the quinone (Q) pool. The Q redox state is thus a function of electron input (reduction) and output (oxidation) and closely reflects the mitochondrial respiratory state. Disruption of electron flux at the level of the cytochrome bc1 complex (cIII) or cytochrome c oxidase (cIV) shifts the Q redox poise to a more reduced state which is generally sensed as respiratory stress. To cope with respiratory stress, many species, but not insects and vertebrates, express alternative oxidase (AOX) which acts as an electron sink for reduced Q and by-passes cIII and cIV. Here, we used Ciona intestinalis AOX xenotopically expressed in mouse mitochondria to study how respiratory states impact the Q poise and how AOX may be used to restore respiration. Particularly interesting is our finding that electron input through succinate dehydrogenase (cII), but not NADH:ubiquinone oxidoreductase (cI), reduces the Q pool almost entirely (>90%) irrespective of the respiratory state. AOX enhances the forward electron transport (FET) from cII thereby decreasing reverse electron transport (RET) and ROS specifically when non-phosphorylating. AOX is not engaged with cI substrates, however, unless a respiratory inhibitor is added. This sheds new light on Q poise signaling, the biological role of cII which enigmatically is the only ETC complex absent from respiratory supercomplexes but yet participates in the tricarboxylic acid (TCA) cycle. Finally, we delineate potential risks and benefits arising from therapeutic AOX transfer.
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12
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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.
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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,
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13
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Havird JC, Noe GR, Link L, Torres A, Logan DC, Sloan DB, Chicco AJ. Do angiosperms with highly divergent mitochondrial genomes have altered mitochondrial function? Mitochondrion 2019; 49:1-11. [PMID: 31229574 PMCID: PMC6885534 DOI: 10.1016/j.mito.2019.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/07/2019] [Accepted: 06/17/2019] [Indexed: 02/06/2023]
Abstract
Angiosperm mitochondrial (mt) genes are generally slow-evolving, but multiple lineages have undergone dramatic accelerations in rates of nucleotide substitution and extreme changes in mt genome structure. While molecular evolution in these lineages has been investigated, very little is known about their mt function. Some studies have suggested altered respiration in individual taxa, although there are several reasons why mt variation might be neutral in others. Here, we develop a new protocol to characterize respiration in isolated plant mitochondria and apply it to species of Silene with mt genomes that are rapidly evolving, highly fragmented, and exceptionally large (~11 Mbp). This protocol, complemented with traditional measures of plant fitness, cytochrome c oxidase activity assays, and fluorescence microscopy, was also used to characterize inter- and intraspecific variation in mt function. Contributions of the individual "classic" OXPHOS complexes, the alternative oxidase, and external NADH dehydrogenases to overall mt respiratory flux were found to be similar to previously studied angiosperms with more typical mt genomes. Some differences in mt function could be explained by inter- and intraspecific variation. This study suggests that Silene species with peculiar mt genomes still show relatively normal mt respiration. This may be due to strong purifying selection on mt variants, coevolutionary responses in the nucleus, or a combination of both. Future experiments should explore such questions using a comparative framework and investigating other lineages with unusual mitogenomes.
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Affiliation(s)
- Justin C Havird
- Department of Biology, Colorado State University, Fort Collins, CO, USA; Department of Integrative Biology, The University of Texas, Austin, TX, USA.
| | - Gregory R Noe
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Luke Link
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Amber Torres
- Department of Biology, Colorado State University, Fort Collins, CO, USA.
| | - David C Logan
- IRHS, INRA, Université d'Angers, AGROCAMPUS-Ouest, SFR 4207 QUASAV, 49071 Beaucouzé cedex, France
| | - Daniel B Sloan
- Department of Biology, Colorado State University, Fort Collins, CO, USA.
| | - Adam J Chicco
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
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14
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Nitric Oxide Regulates Seedling Growth and Mitochondrial Responses in Aged Oat Seeds. Int J Mol Sci 2018; 19:ijms19041052. [PMID: 29614792 PMCID: PMC5979601 DOI: 10.3390/ijms19041052] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 03/24/2018] [Accepted: 03/26/2018] [Indexed: 01/09/2023] Open
Abstract
Mitochondria are the source of reactive oxygen species (ROS) in plant cells and play a central role in the mitochondrial electron transport chain (ETC) and tricarboxylic acid cycle (TCA) cycles; however, ROS production and regulation for seed germination, seedling growth, as well as mitochondrial responses to abiotic stress, are not clear. This study was conducted to obtain basic information on seed germination, embryo mitochondrial antioxidant responses, and protein profile changes in artificial aging in oat seeds (Avena sativa L.) exposed to exogenous nitric oxide (NO) treatment. The results showed that the accumulation of H2O2 in mitochondria increased significantly in aged seeds. Artificial aging can lead to a loss of seed vigor, which was shown by a decline in seed germination and the extension of mean germination time (MGT). Seedling growth was also inhibited. Some enzymes, including catalase (CAT), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR), maintained a lower level in the ascorbate-glutathione (AsA-GSH) scavenging system. Proteomic analysis revealed that the expression of some proteins related to the TCA cycle were down-regulated and several enzymes related to mitochondrial ETC were up-regulated. With the application of 0.05 mM NO in aged oat seeds, a protective effect was observed, demonstrated by an improvement in seed vigor and increased H2O2 scavenging ability in mitochondria. There were also higher activities of CAT, GR, MDHAR, and DHAR in the AsA-GSH scavenging system, enhanced TCA cycle-related enzymes (malate dehydrogenase, succinate-CoA ligase, fumarate hydratase), and activated alternative pathways, as the cytochrome pathway was inhibited. Therefore, our results indicated that seedling growth and seed germinability could retain a certain level in aged oat seeds, predominantly depending on the lower NO regulation of the TCA cycle and AsA-GSH. Thus, it could be concluded that the application of 0.05 mM NO in aged oat seeds improved seed vigor by enhancing the mitochondrial TCA cycle and activating alternative pathways for improvement.
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15
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Del-Saz NF, Ribas-Carbo M, McDonald AE, Lambers H, Fernie AR, Florez-Sarasa I. An In Vivo Perspective of the Role(s) of the Alternative Oxidase Pathway. TRENDS IN PLANT SCIENCE 2018; 23:206-219. [PMID: 29269217 DOI: 10.1016/j.tplants.2017.11.006] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 10/18/2017] [Accepted: 11/15/2017] [Indexed: 05/02/2023]
Abstract
Despite intense research on the in vitro characterization of regulatory factors modulating the alternative oxidase (AOX) pathway, the regulation of its activity in vivo is still not fully understood. Advances concerning in vivo regulation of AOX based on the oxygen-isotope fractionation technique are reviewed, and regulatory factors that merit future research are highlighted. In addition, we review and discuss the main biological functions assigned to the plant AOX, and suggest future experiments involving in vivo activity measurements to test different hypothesized physiological roles.
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Affiliation(s)
- Néstor Fernández Del-Saz
- Grup de Recerca en Biologia de les Plantes en Condicions Mediterranies, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122 Palma de Mallorca, Spain
| | - Miquel Ribas-Carbo
- Grup de Recerca en Biologia de les Plantes en Condicions Mediterranies, Universitat de les Illes Balears, Carretera de Valldemossa Km 7.5, 07122 Palma de Mallorca, Spain
| | - Allison E McDonald
- Department of Biology, Wilfrid Laurier University, Science Building, 75 University Avenue West, Waterloo, ON N2L 3C5, Canada
| | - Hans Lambers
- School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Crawley (Perth), Western Australia 6009, Australia
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Igor Florez-Sarasa
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
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16
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Planchet E, Lothier J, Limami AM. Hypoxic Respiratory Metabolism in Plants: Reorchestration of Nitrogen and Carbon Metabolisms. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/978-3-319-68703-2_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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17
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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: 35] [Impact Index Per Article: 5.0] [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.
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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
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18
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Colombié S, Beauvoit B, Nazaret C, Bénard C, Vercambre G, Le Gall S, Biais B, Cabasson C, Maucourt M, Bernillon S, Moing A, Dieuaide‐Noubhani M, Mazat J, Gibon Y. Respiration climacteric in tomato fruits elucidated by constraint-based modelling. THE NEW PHYTOLOGIST 2017; 213:1726-1739. [PMID: 27861943 PMCID: PMC6079640 DOI: 10.1111/nph.14301] [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] [Received: 07/20/2016] [Accepted: 09/22/2016] [Indexed: 05/18/2023]
Abstract
Tomato is a model organism to study the development of fleshy fruit including ripening initiation. Unfortunately, few studies deal with the brief phase of accelerated ripening associated with the respiration climacteric because of practical problems involved in measuring fruit respiration. Because constraint-based modelling allows predicting accurate metabolic fluxes, we investigated the respiration and energy dissipation of fruit pericarp at the breaker stage using a detailed stoichiometric model of the respiratory pathway, including alternative oxidase and uncoupling proteins. Assuming steady-state, a metabolic dataset was transformed into constraints to solve the model on a daily basis throughout tomato fruit development. We detected a peak of CO2 released and an excess of energy dissipated at 40 d post anthesis (DPA) just before the onset of ripening coinciding with the respiration climacteric. We demonstrated the unbalanced carbon allocation with the sharp slowdown of accumulation (for syntheses and storage) and the beginning of the degradation of starch and cell wall polysaccharides. Experiments with fruits harvested from plants cultivated under stress conditions confirmed the concept. We conclude that modelling with an accurate metabolic dataset is an efficient tool to bypass the difficulty of measuring fruit respiration and to elucidate the underlying mechanisms of ripening.
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Affiliation(s)
- Sophie Colombié
- UMR 1332 Biologie du Fruit et PathologieINRAVillenave d'OrnonF‐33883France
| | - Bertrand Beauvoit
- UMR 1332 Biologie du Fruit et PathologieINRAVillenave d'OrnonF‐33883France
- Université de Bordeaux146 rue Léo‐SaignatBordeaux CedexF‐33076France
| | - Christine Nazaret
- ENSTBB‐Institut Polytechnique de BordeauxInstitut de Mathématiques de Bordeaux351 Cours de la LiberationTalence33400France
| | - Camille Bénard
- UMR 1332 Biologie du Fruit et PathologieINRAVillenave d'OrnonF‐33883France
| | - Gilles Vercambre
- UR 1115 Plantes et Systèmes de culture HorticolesINRAAvignon Cedex 9F84914France
| | - Sophie Le Gall
- UR 1268 Biopolymères, Interactions, AssemblagesINRANantesF‐44316France
| | - Benoit Biais
- UMR 1332 Biologie du Fruit et PathologieINRAVillenave d'OrnonF‐33883France
- Université de Bordeaux146 rue Léo‐SaignatBordeaux CedexF‐33076France
| | - Cécile Cabasson
- UMR 1332 Biologie du Fruit et PathologieINRAVillenave d'OrnonF‐33883France
- Université de Bordeaux146 rue Léo‐SaignatBordeaux CedexF‐33076France
| | - Mickaël Maucourt
- UMR 1332 Biologie du Fruit et PathologieINRAVillenave d'OrnonF‐33883France
- Université de Bordeaux146 rue Léo‐SaignatBordeaux CedexF‐33076France
| | - Stéphane Bernillon
- UMR 1332 Biologie du Fruit et PathologieINRAVillenave d'OrnonF‐33883France
| | - Annick Moing
- UMR 1332 Biologie du Fruit et PathologieINRAVillenave d'OrnonF‐33883France
| | - Martine Dieuaide‐Noubhani
- UMR 1332 Biologie du Fruit et PathologieINRAVillenave d'OrnonF‐33883France
- Université de Bordeaux146 rue Léo‐SaignatBordeaux CedexF‐33076France
| | - Jean‐Pierre Mazat
- Université de Bordeaux146 rue Léo‐SaignatBordeaux CedexF‐33076France
- IBGC‐CNRS1 rue Camille Saint‐SaënsBordeaux CedexF‐33077France
| | - Yves Gibon
- UMR 1332 Biologie du Fruit et PathologieINRAVillenave d'OrnonF‐33883France
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19
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Atkin OK, Bahar NHA, Bloomfield KJ, Griffin KL, Heskel MA, Huntingford C, de la Torre AM, Turnbull MH. Leaf Respiration in Terrestrial Biosphere Models. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2017. [DOI: 10.1007/978-3-319-68703-2_6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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20
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Affourtit C, Bailey SJ, Jones AM, Smallwood MJ, Winyard PG. On the mechanism by which dietary nitrate improves human skeletal muscle function. Front Physiol 2015; 6:211. [PMID: 26283970 PMCID: PMC4518145 DOI: 10.3389/fphys.2015.00211] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 07/14/2015] [Indexed: 12/26/2022] Open
Abstract
Inorganic nitrate is present at high levels in beetroot and celery, and in green leafy vegetables such as spinach and lettuce. Though long believed inert, nitrate can be reduced to nitrite in the human mouth and, further, under hypoxia and/or low pH, to nitric oxide. Dietary nitrate has thus been associated favorably with nitric-oxide-regulated processes including blood flow and energy metabolism. Indeed, the therapeutic potential of dietary nitrate in cardiovascular disease and metabolic syndrome-both aging-related medical disorders-has attracted considerable recent research interest. We and others have shown that dietary nitrate supplementation lowers the oxygen cost of human exercise, as less respiratory activity appears to be required for a set rate of skeletal muscle work. This striking observation predicts that nitrate benefits the energy metabolism of human muscle, increasing the efficiency of either mitochondrial ATP synthesis and/or of cellular ATP-consuming processes. In this mini-review, we evaluate experimental support for the dietary nitrate effects on muscle bioenergetics and we critically discuss the likelihood of nitric oxide as the molecular mediator of such effects.
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Affiliation(s)
- Charles Affourtit
- School of Biomedical and Healthcare Sciences, Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth University Plymouth, UK
| | - Stephen J Bailey
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
| | - Andrew M Jones
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
| | - Miranda J Smallwood
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter Exeter, UK
| | - Paul G Winyard
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter Exeter, UK
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21
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Mitochondrial Signaling in Plants Under Hypoxia: Use of Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS). SIGNALING AND COMMUNICATION IN PLANTS 2015. [DOI: 10.1007/978-3-319-10079-1_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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22
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Fu J, Sun Y, Chu X, Xu Y, Hu T. Exogenous 5-aminolevulenic acid promotes seed germination in Elymus nutans against oxidative damage induced by cold stress. PLoS One 2014; 9:e107152. [PMID: 25207651 PMCID: PMC4160216 DOI: 10.1371/journal.pone.0107152] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 08/10/2014] [Indexed: 11/18/2022] Open
Abstract
The protective effects of 5-aminolevulenic acid (ALA) on germination of Elymus nutans Griseb. seeds under cold stress were investigated. Seeds of E. nutans (Damxung, DX and Zhengdao, ZD) were pre-soaked with various concentrations (0, 0.1, 0.5, 1, 5, 10 and 25 mg l−1) of ALA for 24 h before germination under cold stress (5°C). Seeds of ZD were more susceptible to cold stress than DX seeds. Both seeds treated with ALA at low concentrations (0.1–1 mg l−1) had higher final germination percentage (FGP) and dry weight at 5°C than non-ALA-treated seeds, whereas exposure to higher ALA concentrations (5–25 mg l−1) brought about a dose dependent decrease. The highest FGP and dry weight of germinating seeds were obtained from seeds pre-soaked with 1 mg l−1 ALA. After 5 d of cold stress, pretreatment with ALA provided significant protection against cold stress in the germinating seeds, significantly enhancing seed respiration rate and ATP synthesis. ALA pre-treatment also increased reduced glutathione (GSH), ascorbic acid (AsA), total glutathione, and total ascorbate concentrations, and the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR), whereas decreased the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2), and superoxide radical (O2•−) release in both germinating seeds under cold stress. In addition, application of ALA increased H+-ATPase activity and endogenous ALA concentration compared with cold stress alone. Results indicate that ALA considered as an endogenous plant growth regulator could effectively protect E. nutans seeds from cold-induced oxidative damage during germination without any adverse effect.
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Affiliation(s)
- Juanjuan Fu
- Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi Province, P. R. China
| | - Yongfang Sun
- Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi Province, P. R. China
| | - Xitong Chu
- Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi Province, P. R. China
| | - Yuefei Xu
- Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi Province, P. R. China
- * E-mail: (YX); (TH)
| | - Tianming Hu
- Department of Grassland Science, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi Province, P. R. China
- * E-mail: (YX); (TH)
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23
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Li Z, Liang WS, Carr JP. Effects of modifying alternative respiration on nitric oxide-induced virus resistance and PR1 protein accumulation. J Gen Virol 2014; 95:2075-2081. [PMID: 24903327 DOI: 10.1099/vir.0.066662-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Nitric oxide (NO) is an important defensive signal in plants but its effects on virus infection are not well understood. Administration of NO-releasing compounds immediately before inoculation of tobacco leaves with potato virus X and tobacco mosaic virus decreased the accumulation of virus, indicating that NO can induce resistance rapidly. Resistance induction was inhibited by co-administration with an NO-scavenging compound or when experiments were done in transgenic tobacco plants expressing increased alternative respiratory pathway capacity due to constitutive expression of the plant mitochondrial enzyme, alternative oxidase (AOX). These results indicate that NO, which inhibits electron transport chain activity, is triggering defensive signalling by inducing changes in mitochondrial reactive oxygen species levels that are in turn regulated by AOX. Experiments using nahG-transgenic plants, which cannot accumulate the defensive plant hormone salicylic acid (SA) showed that NO rapidly induces resistance to virus infection independently of SA. However, this initial state of resistance may be transient. Subsequently, by 5 days post-treatment, NO had caused an increase in pathogenesis-related protein 1 (PR1) expression (a proxy for increased SA biosynthesis), which correlated with a longer-term state of resistance to virus infection. The induction by NO of PR1 accumulation was modified in AOX-transgenic plants. This indicates that the influence of NO on defensive gene expression is in part mediated through its effects on mitochondria.
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Affiliation(s)
- Zheng Li
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Wu-Sheng Liang
- Institute of Biotechnology, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - John P Carr
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
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24
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Young L, May B, Pendlebury-Watt A, Shearman J, Elliott C, Albury MS, Shiba T, Inaoka DK, Harada S, Kita K, Moore AL. Probing the ubiquinol-binding site of recombinant Sauromatum guttatum alternative oxidase expressed in E. coli membranes through site-directed mutagenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1219-25. [PMID: 24530866 DOI: 10.1016/j.bbabio.2014.01.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/23/2014] [Accepted: 01/28/2014] [Indexed: 11/16/2022]
Abstract
In the present paper we have investigated the effect of mutagenesis of a number of highly conserved residues (R159, D163, L177 and L267) which we have recently shown to line the hydrophobic inhibitor/substrate cavity in the alternative oxidases (AOXs). Measurements of respiratory activity in rSgAOX expressed in Escherichia coli FN102 membranes indicate that all mutants result in a decrease in maximum activity of AOX and in some cases (D163 and L177) a decrease in the apparent Km (O2). Of particular importance was the finding that when the L177 and L267 residues, which appear to cause a bottleneck in the hydrophobic cavity, are mutated to alanine the sensitivity to AOX antagonists is reduced. When non-AOX anti-malarial inhibitors were also tested against these mutants widening the bottleneck through removal of isobutyl side chain allowed access of these bulkier inhibitors to the active-site and resulted in inhibition. Results are discussed in terms of how these mutations have altered the way in which the AOX's catalytic cycle is controlled and since maximum activity is decreased we predict that such mutations result in an increase in the steady state level of at least one O2-derived AOX intermediate. Such mutations should therefore prove to be useful in future stopped-flow and electron paramagnetic resonance experiments in attempts to understand the catalytic cycle of the alternative oxidase which may prove to be important in future rational drug design to treat diseases such as trypanosomiasis. Furthermore since single amino acid mutations in inhibitor/substrate pockets have been found to be the cause of multi-drug resistant strains of malaria, the decrease in sensitivity to main AOX antagonists observed in the L-mutants studied in this report suggests that an emergence of drug resistance to trypanosomiasis may also be possible. Therefore we suggest that the design of future AOX inhibitors should have structures that are less reliant on the orientation by the two-leucine residues. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
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Affiliation(s)
- Luke Young
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Benjamin May
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Alice Pendlebury-Watt
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Julia Shearman
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Catherine Elliott
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Mary S Albury
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Tomoo Shiba
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Daniel Ken Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shigeharu Harada
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Anthony L Moore
- Biochemistry and Molecular Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK.
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Igamberdiev AU, Eprintsev AT, Fedorin DN, Popov VN. Phytochrome-mediated regulation of plant respiration and photorespiration. PLANT, CELL & ENVIRONMENT 2014; 37:290-299. [PMID: 23772790 DOI: 10.1111/pce.12155] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 06/02/2023]
Abstract
The expression of genes encoding various enzymes participating in photosynthetic and respiratory metabolism is regulated by light via the phytochrome system. While many photosynthetic, photorespiratory and some respiratory enzymes, such as the rotenone-insensitive NADH and NADPH dehydrogenases and the alternative oxidase, are stimulated by light, succinate dehydrogenase, subunits of the pyruvate dehydrogenase complex, cytochrome oxidase and fumarase are inhibited via the phytochrome mechanism. The effect of light, therefore, imposes limitations on the tricarboxylic acid cycle and on the mitochondrial electron transport coupled to ATP synthesis, while the non-coupled pathways become activated. Phytochrome-mediated regulation of gene expression also creates characteristic distribution patterns of photosynthetic, photorespiratory and respiratory enzymes across the leaf generating different populations of mitochondria, either enriched by glycine decarboxylase (in the upper part) or by succinate dehydrogenase (in the bottom part of the leaf).
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Affiliation(s)
- Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada, A1B 3X9
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26
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Cabrera-Orefice A, Chiquete-Félix N, Espinasa-Jaramillo J, Rosas-Lemus M, Guerrero-Castillo S, Peña A, Uribe-Carvajal S. The branched mitochondrial respiratory chain from Debaryomyces hansenii: Components and supramolecular organization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:73-84. [DOI: 10.1016/j.bbabio.2013.07.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/23/2013] [Accepted: 07/25/2013] [Indexed: 11/29/2022]
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Mallo N, Lamas J, Leiro JM. Evidence of an alternative oxidase pathway for mitochondrial respiration in the scuticociliate Philasterides dicentrarchi. Protist 2013; 164:824-36. [PMID: 24211656 DOI: 10.1016/j.protis.2013.09.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 09/25/2013] [Accepted: 09/28/2013] [Indexed: 11/17/2022]
Abstract
The presence of an alternative oxidase (AOX) in the mitochondria of the scuticociliate P. dicentrarchi was investigated. The mitochondrial oxygen consumption was measured in the presence of KCN, an inhibitor of cytochrome pathway (CP) respiration and salicylhydroxamic acid (SHAM), a specific inhibitor of alternative pathway (AP) respiration. AOX expression was monitored by western blotting with an AOX polyclonal antibody. The results showed that P. dicentrarchi possesses a branched mitochondrial electron transport chain with both cyanide-sensitive and -insensitive oxygen consumption. Mitochondrial respiration was partially inhibited by cyanide and completely inhibited by the combination of cyanide and SHAM, which is direct evidence for the existence of an AP in this ciliate. SHAM significantly inhibited in vitro growth of trophozoites both under normoxic and hypoxic conditions. AOX is a 42kD monomeric protein inducible by hypoxic conditions in experimental infections and by CP inhibitors such as cyanide and antimycin A, or by AP inhibitors such as SHAM. CP respiration was greatly stimulated during the exponential growth phase, while AP respiration increased during the stationary phase, in which AOX expression is induced. As the host does not possess AOX, and because during infection P. dicentrarchi respires via AP, it may be possible to develop inhibitors targeting the AP as a novel anti-scuticociliate therapy.
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Affiliation(s)
- Natalia Mallo
- Laboratorio de Parasitología, Departamento de Microbiología y Parasitología, Instituto de Investigación y Análisis Alimentarios, c/ Constantino Candeira s/n, 15782, Universidad de Santiago de Compostela; Santiago de Compostela (La Coruña, Spain)
| | - Jesús Lamas
- Departamento de Biología Celular y Ecología; Universidad de Santiago de Compostela; Santiago de Compostela, (La Coruña, Spain)
| | - José Manuel Leiro
- Laboratorio de Parasitología, Departamento de Microbiología y Parasitología, Instituto de Investigación y Análisis Alimentarios, c/ Constantino Candeira s/n, 15782, Universidad de Santiago de Compostela; Santiago de Compostela (La Coruña, Spain).
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Stanić M, Zakrzewska J, Hadžibrahimović M, Zižić M, Marković Z, Vučinić Z, Zivić M. Oxygen regulation of alternative respiration in fungus Phycomyces blakesleeanus: connection with phosphate metabolism. Res Microbiol 2013; 164:770-8. [PMID: 23542427 DOI: 10.1016/j.resmic.2013.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 03/11/2013] [Indexed: 11/27/2022]
Abstract
Environmental changes can often result in oxygen deficiency which influences cellular energy metabolism, but such effects have been insufficiently studied in fungi. The effects of oxygen deprivation on respiration and phosphate metabolites in Phycomyces blakesleeanus were investigated by oxygen electrode and (31)P NMR spectroscopy. Mycelium was incubated in hypoxic and anoxic conditions for 1.5, 3 and 5 h and then reoxygenated. Participation of alternative oxidase (AOX) in total respiration increased gradually in both treatments and after 5 h of anoxia exceeded a value 50% higher than in control. Shortly after reintroduction of oxygen into the system AOX level decreased close to the control level. Oxygen deprivation also caused a reversible decrease of polyphosphate/inorganic phosphate ratio (PPc/Pi), which was strongly correlated with the increase of AOX participation in total respiration. Unexpectedly, ATP content remained almost constant, probably due to the ability of PolyP to sustain energy and phosphate homeostasis of the cell under stress conditions. This was further substantiated by the effects of azide, a cytochrome c oxidase inhibitor, which also decreased PPc/Pi ratio, but to a smaller extent in oxygen deprived than control and reoxygenated specimens.
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Affiliation(s)
- Marina Stanić
- Department of Life Sciences, Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia.
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Moore AL, Shiba T, Young L, Harada S, Kita K, Ito K. Unraveling the heater: new insights into the structure of the alternative oxidase. ANNUAL REVIEW OF PLANT BIOLOGY 2013; 64:637-63. [PMID: 23638828 DOI: 10.1146/annurev-arplant-042811-105432] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The alternative oxidase is a membrane-bound ubiquinol oxidase found in the majority of plants as well as many fungi and protists, including pathogenic organisms such as Trypanosoma brucei. It catalyzes a cyanide- and antimycin-A-resistant oxidation of ubiquinol and the reduction of oxygen to water, short-circuiting the mitochondrial electron-transport chain prior to proton translocation by complexes III and IV, thereby dramatically reducing ATP formation. In plants, it plays a key role in cellular metabolism, thermogenesis, and energy homeostasis and is generally considered to be a major stress-induced protein. We describe recent advances in our understanding of this protein's structure following the recent successful crystallization of the alternative oxidase from T. brucei. We focus on the nature of the active site and ubiquinol-binding channels and propose a mechanism for the reduction of oxygen to water based on these structural insights. We also consider the regulation of activity at the posttranslational and retrograde levels and highlight challenges for future research.
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Affiliation(s)
- Anthony L Moore
- Biochemistry and Molecular Biology, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom.
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30
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Minagawa N. [Mitochondria as targets of chemotherapy]. YAKUGAKU ZASSHI 2012; 132:1093-8. [PMID: 23037693 DOI: 10.1248/yakushi.12-00220-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Living organisms have developed a wide variety of energy metabolism to survive within the specialized environments. There is a remarkable diversity in mitochondrial electron transport system, which might be potential targets for chemotherapy. Atovaquone, clinically used to treat malaria and pneumocystis pneumonia, is a specific inhibitor of Qo site in the cytochrome bc(1) complex of Plasmodium falciparum and Pneumocystis jirovecii. Phytopathogenic fungus, Ascochyta viciae produces two antibiotics, ascochlorin and ascofuranone. Ascochlorin specifically binds to inhibit the electron transport of both Qi and Qo sites in cytochrome bc(1) complex. Besides the unique respiratory inhibition, further investigation is in progress to elucidate the effects on cancer cells. On the other hand, ascofuranone specifically inhibits cyanide-insensitive trypanosome alternative oxidase, which is a sole terminal oxidase in the mitochondrion of Trypanosoma brucei, causative of African trypanosomiasis. In vivo study suggests that ascofuranone is a promising candidate for chemotherapeutic agents to treat African trypanosomiasis.
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Affiliation(s)
- Nobuko Minagawa
- Department of Health Chemistry, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha, Niigata, Japan.
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31
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Xu F, Yuan S, Zhang DW, Lv X, Lin HH. The role of alternative oxidase in tomato fruit ripening and its regulatory interaction with ethylene. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:5705-16. [PMID: 22915749 PMCID: PMC3444281 DOI: 10.1093/jxb/ers226] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Although the alternative oxidase (AOX) has been proposed to play a role in fruit development, the function of AOX in fruit ripening is unclear. To gain further insight into the role of AOX in tomato fruit ripening, transgenic tomato plants 35S-AOX1a and 35S-AOX-RNAi were generated. Tomato plants with reduced LeAOX levels exhibited retarded ripening; reduced carotenoids, respiration, and ethylene production; and the down-regulation of ripening-associated genes. Moreover, no apparent respiratory climacteric occurred in the AOX-reduced tomato fruit, indicating that AOX might play an important role in climacteric respiration. In contrast, the fruit that overexpressed LeAOX1a accumulated more lycopene, though they displayed a similar pattern of ripening to wild-type fruit. Ethylene application promoted fruit ripening and anticipated ethylene production and respiration, including the alternative pathway respiration. Interestingly, the transgenic plants with reduced LeAOX levels failed to ripen after 1-methylcyclopropene (1-MCP) treatment, while such inhibition was notably less effective in 35S-AOX1a fruit. These findings indicate that AOX is involved in respiratory climacteric and ethylene-mediated fruit ripening of tomato.
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Affiliation(s)
- Fei Xu
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan UniversityChengdu 610064China
- These authors contributed equally to this work
| | - Shu Yuan
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan UniversityChengdu 610064China
- These authors contributed equally to this work
| | - Da-Wei Zhang
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan UniversityChengdu 610064China
- These authors contributed equally to this work
| | - Xin Lv
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan UniversityChengdu 610064China
| | - Hong-Hui Lin
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan UniversityChengdu 610064China
- State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan UniversityChengdu 610065China
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32
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Lenaz G. Mitochondria and reactive oxygen species. Which role in physiology and pathology? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 942:93-136. [PMID: 22399420 DOI: 10.1007/978-94-007-2869-1_5] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Oxidative stress is among the major causes of toxicity due to interaction of Reactive Oxygen Species (ROS) with cellular macromolecules and structures and interference with signal transduction pathways. The mitochondrial respiratory chain, specially from Complexes I and III, is considered the main origin of ROS particularly under conditions of high membrane potential, but several other sources may be important for ROS generation, such as mitochondrial p66(Shc), monoamine oxidase, α-ketoglutarate dehydogenase, besides redox cycling of redox-active molecules. ROS are able to oxidatively modify lipids, proteins, carbohydrates and nucleic acids in mitochondria and to activate/inactivate signalling pathways by oxidative modification of redox-active factors. Cells are endowed with several defence mechanisms including repair or removal of damaged molecules, and antioxidant systems, either enzymatic or non-enzymatic. Oxidative stress is at the basis of ageing and many pathological disorders, such as ischemic diseases, neurodegenerative diseases, diabetes, and cancer, although the underlying mechanisms are not always completely understood.
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Affiliation(s)
- Giorgio Lenaz
- Dipartimento di Biochimica, Università di Bologna, Bologna, Italy.
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Inoue K, Tsurumi T, Ishii H, Park P, Ikeda K. Cytological evaluation of the effect of azoxystrobin and alternative oxidase inhibitors in Botrytis cinerea. FEMS Microbiol Lett 2011; 326:83-90. [PMID: 22092932 DOI: 10.1111/j.1574-6968.2011.02438.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 10/09/2011] [Accepted: 10/10/2011] [Indexed: 11/29/2022] Open
Abstract
Azoxystrobin (AZ), a strobilurin-derived fungicide, is known to inhibit mitochondrial respiration in fungi by blocking the electron transport chain in the inner mitochondrial membrane. Germination was strongly inhibited when Botrytis cinerea spore suspension was treated with AZ and the alternative oxidase (AOX) inhibitors, salicylhydroxamic acid (SHAM) and n-propyl gallate. However, chemical death indicators trypan blue and propidium iodide showed that those spores were still alive. When the spore suspension in the AZ and SHAM solution was replaced with distilled water, the germination rate almost recovered, at least during the first 2 days of incubation with AZ and SHAM solution. No morphological alteration was detected in the cells treated with AZ and SHAM, especially in mitochondria, using transmission electron microscopy. Therefore, simultaneous application of AZ and AOX inhibitors has a fungistatic, rather than a fungicidal, action.
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Affiliation(s)
- Kanako Inoue
- Stress Cytology Laboratory, Graduate School of Agriculture, Kobe University, Kobe, Japan
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34
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Meilhoc E, Boscari A, Bruand C, Puppo A, Brouquisse R. Nitric oxide in legume-rhizobium symbiosis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2011; 181:573-81. [PMID: 21893254 DOI: 10.1016/j.plantsci.2011.04.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 04/07/2011] [Accepted: 04/12/2011] [Indexed: 05/08/2023]
Abstract
Nitric oxide (NO) is a gaseous signaling molecule with a broad spectrum of regulatory functions in plant growth and development. NO has been found to be involved in various pathogenic or symbiotic plant-microbe interactions. During the last decade, increasing evidence of the occurrence of NO during legume-rhizobium symbioses has been reported, from early steps of plant-bacteria interaction, to the nitrogen-fixing step in mature nodules. This review focuses on recent advances on NO production and function in nitrogen-fixing symbiosis. First, the potential plant and bacterial sources of NO, including NO synthase-like, nitrate reductase or electron transfer chains of both partners, are presented. Then responses of plant and bacterial cells to the presence of NO are presented in the context of the N(2)-fixing symbiosis. Finally, the roles of NO as either a regulatory signal of development, or a toxic compound with inhibitory effects on nitrogen fixation, or an intermediate involved in energy metabolism, during symbiosis establishment and nodule functioning are discussed.
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Affiliation(s)
- Eliane Meilhoc
- INRA, Laboratoire des Interactions Plantes-Microorganismes, UMR441, F-31326 Castanet-Tolosan, France
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35
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Chen KM, Piippo M, Holmström M, Nurmi M, Pakula E, Suorsa M, Aro EM. A chloroplast-targeted DnaJ protein AtJ8 is negatively regulated by light and has rapid turnover in darkness. JOURNAL OF PLANT PHYSIOLOGY 2011; 168:1780-3. [PMID: 21592617 DOI: 10.1016/j.jplph.2011.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 04/12/2011] [Accepted: 04/12/2011] [Indexed: 05/20/2023]
Abstract
The DnaJ proteins (also called as J proteins, J domain proteins or HSP40 proteins) function as molecular co-chaperones for the HSP70 proteins. We assessed the expression of the small chloroplast-targeted DnaJ protein, the AtJ8 protein, by subjecting the wild type Arabidopsis plants to different illumination conditions. It is shown that the expression of the transcripts and proteins of the ATJ8 gene is primarily regulated at the level of transcription. When plants were incubated under high light for 3h, both the transcripts and proteins were completely abolished. Upon transfer of plants to darkness, the transcripts started rapidly accumulating, and subsequently, the AtJ8 protein became visible after 2h in darkness. Conversely, incubation of plants in darkness or under low light intensities induced expression of the ATJ8 transcripts and proteins. Feeding plants with sugars clearly decreased the transcript and protein levels, and incubation with cycloheximide revealed a rapid turnover for AtJ8 in darkness. Moreover, the AtJ8 protein was found to be nearly missing from the var1 mutant, which lacks the FTSH5 protease. It is concluded that AtJ8 is expressed mainly in darkness, is prone to a rapid turnover but is partially stabilized by the FTSH proteases.
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Affiliation(s)
- Kun-Ming Chen
- College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
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Lee WS, Fu SF, Verchot-Lubicz J, Carr JP. Genetic modification of alternative respiration in Nicotiana benthamiana affects basal and salicylic acid-induced resistance to potato virus X. BMC PLANT BIOLOGY 2011; 11:41. [PMID: 21356081 PMCID: PMC3058079 DOI: 10.1186/1471-2229-11-41] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 02/28/2011] [Indexed: 05/06/2023]
Abstract
BACKGROUND Salicylic acid (SA) regulates multiple anti-viral mechanisms, including mechanism(s) that may be negatively regulated by the mitochondrial enzyme, alternative oxidase (AOX), the sole component of the alternative respiratory pathway. However, studies of this mechanism can be confounded by SA-mediated induction of RNA-dependent RNA polymerase 1, a component of the antiviral RNA silencing pathway. We made transgenic Nicotiana benthamiana plants in which alternative respiratory pathway capacity was either increased by constitutive expression of AOX, or decreased by expression of a dominant-negative mutant protein (AOX-E). N. benthamiana was used because it is a natural mutant that does not express a functional RNA-dependent RNA polymerase 1. RESULTS Antimycin A (an alternative respiratory pathway inducer and also an inducer of resistance to viruses) and SA triggered resistance to tobacco mosaic virus (TMV). Resistance to TMV induced by antimycin A, but not by SA, was inhibited in Aox transgenic plants while SA-induced resistance to this virus appeared to be stronger in Aox-E transgenic plants. These effects, which were limited to directly inoculated leaves, were not affected by the presence or absence of a transgene constitutively expressing a functional RNA-dependent RNA polymerase (MtRDR1). Unexpectedly, Aox-transgenic plants infected with potato virus X (PVX) showed markedly increased susceptibility to systemic disease induction and virus accumulation in inoculated and systemically infected leaves. SA-induced resistance to PVX was compromised in Aox-transgenic plants but plants expressing AOX-E exhibited enhanced SA-induced resistance to this virus. CONCLUSIONS We conclude that AOX-regulated mechanisms not only play a role in SA-induced resistance but also make an important contribution to basal resistance against certain viruses such as PVX.
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Affiliation(s)
- Wing-Sham Lee
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Shih-Feng Fu
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Jeanmarie Verchot-Lubicz
- Oklahoma State University, Department of Entomology and Plant Pathology, 127 Noble Research Center, Stillwater, OK 74078, USA
| | - John P Carr
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
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Kruse J, Rennenberg H, Adams MA. Steps towards a mechanistic understanding of respiratory temperature responses. THE NEW PHYTOLOGIST 2011; 189:659-677. [PMID: 21223283 DOI: 10.1111/j.1469-8137.2010.03576.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Temperature crucially affects the speed of metabolic processes in poikilotherm organisms, including plants. The instantaneous temperature responses of O(2)-reduction and CO(2)-release can be approximated by Arrhenius kinetics, even though respiratory gas exchange of plants is the net effect of many constituent biochemical processes. Nonetheless, the classical Arrhenius equation must be modified to account for a dynamic response to measurement temperatures. We show that this dynamic response is readily explained by combining Arrhenius and Michaelis-Menten kinetics, as part of a fresh appraisal of metabolic interpretations of instantaneous temperature responses. In combination with recent experimental findings, we argue that control of mitochondrial electron flow is shared among cytochrome oxidase and alternative oxidase under in vivo conditions, and is continuously coordinated. In this way, upstream carbohydrate metabolism and downstream electron transport appear to be optimized according to the demand of ATP, TCA-cycle intermediates and anabolic reducing power under differing metabolic states. We provide a link to the 'Growth and Maintenance Paradigm' of respiration and argue that respiratory temperature responses can be used as a tool to probe metabolic states of plant tissue, such that we can learn more about the mechanisms that govern longer-term acclimatization responses of plant metabolism.
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Affiliation(s)
- Jörg Kruse
- Institute of Forest Botany, Chair of Tree Physiology, Albert-Ludwigs-University Freiburg, Georges-Koehler-Allee 53-54, D-79110 Freiburg, Germany
| | - Heinz Rennenberg
- Institute of Forest Botany, Chair of Tree Physiology, Albert-Ludwigs-University Freiburg, Georges-Koehler-Allee 53-54, D-79110 Freiburg, Germany
| | - Mark A Adams
- Faculty of Agriculture, Food and Natural Resources, The University of Sydney, Sydney, NSW 2006, Australia
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Horchani F, Prévot M, Boscari A, Evangelisti E, Meilhoc E, Bruand C, Raymond P, Boncompagni E, Aschi-Smiti S, Puppo A, Brouquisse R. Both plant and bacterial nitrate reductases contribute to nitric oxide production in Medicago truncatula nitrogen-fixing nodules. PLANT PHYSIOLOGY 2011; 155:1023-36. [PMID: 21139086 PMCID: PMC3032450 DOI: 10.1104/pp.110.166140] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 11/29/2010] [Indexed: 05/09/2023]
Abstract
Nitric oxide (NO) is a signaling and defense molecule of major importance in living organisms. In the model legume Medicago truncatula, NO production has been detected in the nitrogen fixation zone of the nodule, but the systems responsible for its synthesis are yet unknown and its role in symbiosis is far from being elucidated. In this work, using pharmacological and genetic approaches, we explored the enzymatic source of NO production in M. truncatula-Sinorhizobium meliloti nodules under normoxic and hypoxic conditions. When transferred from normoxia to hypoxia, nodule NO production was rapidly increased, indicating that NO production capacity is present in functioning nodules and may be promptly up-regulated in response to decreased oxygen availability. Contrary to roots and leaves, nodule NO production was stimulated by nitrate and nitrite and inhibited by tungstate, a nitrate reductase inhibitor. Nodules obtained with either plant nitrate reductase RNA interference double knockdown (MtNR1/2) or bacterial nitrate reductase-deficient (napA) and nitrite reductase-deficient (nirK) mutants, or both, exhibited reduced nitrate or nitrite reductase activities and NO production levels. Moreover, NO production in nodules was found to be inhibited by electron transfer chain inhibitors, and nodule energy state (ATP-ADP ratio) was significantly reduced when nodules were incubated in the presence of tungstate. Our data indicate that both plant and bacterial nitrate reductase and electron transfer chains are involved in NO synthesis. We propose the existence of a nitrate-NO respiration process in nodules that could play a role in the maintenance of the energy status required for nitrogen fixation under oxygen-limiting conditions.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Renaud Brouquisse
- UMR INRA 1301, CNRS 6243, Université Nice Sophia Antipolis, Interactions Biotiques et Santé Végétale, Institut Agrobiotech, 06903 Sophia Antipolis cedex, France (F.H., M.P., A.B., E.E., E.B., A.P., R.B.); Laboratoire des Interactions Plantes Microorganismes, UMR INRA 441, CNRS 2594, 31326 Castanet Tolosan, France (E.M., C.B.); UR d’Ecologie Végétale, Département des Sciences Biologiques, Faculté des Sciences de Tunis, 1060 Tunis, Tunisia (F.H., S.A.-S.); UMR INRA 619, Biologie du Fruit, F–33883 Villenave d’Ornon cedex, France (P.R.)
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39
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Albury MS, Elliott C, Moore AL. Ubiquinol-binding site in the alternative oxidase: Mutagenesis reveals features important for substrate binding and inhibition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1933-9. [DOI: 10.1016/j.bbabio.2010.01.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 01/11/2010] [Accepted: 01/12/2010] [Indexed: 11/16/2022]
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40
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Lenaz G, Genova ML. Structure and organization of mitochondrial respiratory complexes: a new understanding of an old subject. Antioxid Redox Signal 2010; 12:961-1008. [PMID: 19739941 DOI: 10.1089/ars.2009.2704] [Citation(s) in RCA: 186] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The enzymatic complexes of the mitochondrial respiratory chain have been extensively investigated in their structural and functional properties. A clear distinction is possible today between three complexes in which the difference in redox potential allows proton translocation (complexes I, III, and IV) and those having the mere function to convey electrons to the respiratory chain. We also have a clearer understanding of the structure and function of most respiratory complexes, of their biogenesis and regulation, and of their capacity to generate reactive oxygen species. Past investigations led to the conclusion that the complexes are randomly dispersed and functionally connected by diffusion of smaller redox components, coenzyme Q and cytochrome c. More-recent investigations by native gel electrophoresis and single-particle image processing showed the existence of supramolecular associations. Flux-control analysis demonstrated that complexes I and III in mammals and I, III, and IV in plants kinetically behave as single units, suggesting the existence of substrate channeling. This review discusses conditions affecting the formation of supercomplexes that, besides kinetic advantage, have a role in the stability and assembly of the individual complexes and in preventing excess oxygen radical formation. Disruption of supercomplex organization may lead to functional derangements responsible for pathologic changes.
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Affiliation(s)
- Giorgio Lenaz
- Dipartimento di Biochimica "G. Moruzzi," Alma Mater Studiorum, Università di Bologna, Bologna, Italy.
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41
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Colón AM, Sengupta N, Rhodes D, Dudareva N, Morgan J. A kinetic model describes metabolic response to perturbations and distribution of flux control in the benzenoid network of Petunia hybrida. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 62:64-76. [PMID: 20070567 DOI: 10.1111/j.1365-313x.2010.04127.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
In recent years there has been much interest in the genetic enhancement of plant metabolism; however, attempts at genetic modification are often unsuccessful due to an incomplete understanding of network dynamics and their regulatory properties. Kinetic modeling of plant metabolic networks can provide predictive information on network control and response to genetic perturbations, which allow estimation of flux at any concentration of intermediate or enzyme in the system. In this research, a kinetic model of the benzenoid network was developed to simulate whole network responses to different concentrations of supplied phenylalanine (Phe) in petunia flowers and capture flux redistributions caused by genetic manipulations. Kinetic parameters were obtained by network decomposition and non-linear least squares optimization of data from petunia flowers supplied with either 75 or 150 mm(2)H(5)-Phe. A single set of kinetic parameters simultaneously accommodated labeling and pool size data obtained for all endogenous and emitted volatiles at the two concentrations of supplied (2)H(5)-Phe. The generated kinetic model was validated using flowers from transgenic petunia plants in which benzyl CoA:benzyl alcohol/phenylethanol benzoyltransferase (BPBT) was down-regulated via RNAi. The determined in vivo kinetic parameters were used for metabolic control analysis, in which flux control coefficients were calculated for fluxes around the key branch point at Phe and revealed that phenylacetaldehyde synthase activity is the primary controlling factor for the phenylacetaldehyde branch of the benzenoid network. In contrast, control of flux through the beta-oxidative and non-beta-oxidative pathways is highly distributed.
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Affiliation(s)
- Amy Marshall Colón
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
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42
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Popov VN, Eprintsev AT, Fedorin DN, Igamberdiev AU. Succinate dehydrogenase in Arabidopsis thaliana
is regulated by light via phytochrome A. FEBS Lett 2009; 584:199-202. [DOI: 10.1016/j.febslet.2009.11.057] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 11/13/2009] [Indexed: 11/26/2022]
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43
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Lenaz G, Genova ML. Structural and functional organization of the mitochondrial respiratory chain: a dynamic super-assembly. Int J Biochem Cell Biol 2009; 41:1750-1772. [PMID: 19711505 DOI: 10.1016/j.biocel.2009.04.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The structural organization of the mitochondrial oxidative phosphorylation (OXPHOS) system has received large attention in the past and most investigations led to the conclusion that the respiratory enzymatic complexes are randomly dispersed in the lipid bilayer of the inner membrane and functionally connected by fast diffusion of smaller redox components, Coenzyme Q and cytochrome c. More recent investigations by native gel electrophoresis, however, have shown the existence of supramolecular associations of the respiratory complexes, confirmed by electron microscopy analysis and single particle image processing. Flux control analysis has demonstrated that Complexes I and III in mammalian mitochondria and Complexes I, III, and IV in plant mitochondria kinetically behave as single units with control coefficients approaching unity for each single component, suggesting the existence of substrate channelling within the supercomplexes. The reasons why the presence of substrate channelling for Coenzyme Q and cytochrome c was overlooked in the past are analytically discussed. The review also discusses the forces and the conditions responsible for the formation of the supramolecular units. The function of the supercomplexes appears not to be restricted to kinetic advantages in electron transfer: we discuss evidence on their role in the stability and assembly of the individual complexes and in preventing excess oxygen radical formation. Finally, there is increasing evidence that disruption of the supercomplex organization leads to functional derangements responsible for pathological changes.
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Affiliation(s)
- Giorgio Lenaz
- Dipartimento di Biochimica G. Moruzzi, Università di Bologna, Via Irnerio 48, 40126 Bologna, Italy.
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44
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Characterization of Citrus sinensis type 1 mitochondrial alternative oxidase and expression analysis in biotic stress. Biosci Rep 2009; 30:59-71, 1 p following 71. [DOI: 10.1042/bsr20080180] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The higher plant mitochondrial electron transport chain contains an alternative pathway that ends with the AOX (alternative oxidase). The AOX proteins are encoded by a small gene family composed of two discrete gene subfamilies. Aox1 is present in both monocot and eudicot plants, whereas Aox2 is only present in eudicot plants. We isolated a genomic clone from Citrus sinensis containing the Aox1a gene. The orange Aox1a consists of four exons interrupted by three introns and its promoter harbours diverse putative stress-specific regulatory motifs including pathogen response elements. The role of the Aox1a gene was evaluated during the compatible interaction between C. sinensis and Xanthomonas axonopodis pv. citri and no induction of the Aox1a at the transcriptional level was observed. On the other hand, Aox1a was studied in orange plants during non-host interactions with Pseudomonas syringae pv. tomato and Xanthomonas campestris pv. vesicatoria, which result in hypersensitive response. Both phytopathogens produced a strong induction of Aox1a, reaching a maximum at 8 h post-infiltration. Exogenous application of salicylic acid produced a slight increase in the steady-state level of Aox1a, whereas the application of fungi elicitors showed the highest induction. These results suggest that AOX1a plays a role during biotic stress in non-host plant pathogen interaction.
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45
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Kowaltowski AJ, de Souza-Pinto NC, Castilho RF, Vercesi AE. Mitochondria and reactive oxygen species. Free Radic Biol Med 2009; 47:333-43. [PMID: 19427899 DOI: 10.1016/j.freeradbiomed.2009.05.004] [Citation(s) in RCA: 789] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 04/29/2009] [Accepted: 05/06/2009] [Indexed: 01/02/2023]
Abstract
Mitochondria are a quantitatively relevant source of reactive oxygen species (ROS) in the majority of cell types. Here we review the sources and metabolism of ROS in this organelle, including the conditions that regulate the production of these species, such as mild uncoupling, oxygen tension, respiratory inhibition, Ca2+ and K+ transport, and mitochondrial content and morphology. We discuss substrate-, tissue-, and organism-specific characteristics of mitochondrial oxidant generation. Several aspects of the physiological and pathological roles of mitochondrial ROS production are also addressed.
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Affiliation(s)
- Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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46
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Costa JH, Cardoso HG, Campos MD, Zavattieri A, Frederico AM, Fernandes de Melo D, Arnholdt-Schmitt B. Daucus carota L.--an old model for cell reprogramming gains new importance through a novel expansion pattern of alternative oxidase (AOX) genes. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2009; 47:753-9. [PMID: 19372042 DOI: 10.1016/j.plaphy.2009.03.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 03/19/2009] [Accepted: 03/24/2009] [Indexed: 05/13/2023]
Abstract
The paper highlights Daucus carota L. as an ideal model to complement plant stress research on Arabidopsis thaliana L. Recently, alternative oxidase (AOX) is discussed as functional marker candidate for cell reprogramming upon stress. Carrot is the most studied species for cell reprogramming and our current research reveals that it is the only one that has expanded both AOX sub-family genes. We point to recently published, but not discussed results on conserved differences in the vicinity of the most active functional site of AOX1 and AOX2, which indicate the importance of studying AOX sequence polymorphism, structure and functionality. Thus, stress-inducible experimental systems of D. carota are especially appropriate to bring research on stress tolerance a significant step forward.
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Affiliation(s)
- J H Costa
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, PO Box 6029, 60455-900, Fortaleza, Ceará, Brazil
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47
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The effect of substrate, ADP and uncoupler on the respiration of tomato pollen during incubation in vitro at moderately high temperature. ACTA ACUST UNITED AC 2009; 22:133-40. [PMID: 20033434 DOI: 10.1007/s00497-009-0098-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 05/11/2009] [Indexed: 10/20/2022]
Abstract
Pollen of tomato cv. Supermarmande was collected from greenhouse-grown plants at various intervals throughout the year and arbitrarily classified as of high, medium or low respiratory activity on the basis of CO(2) production during 8 h incubation in vitro at 30 degrees C, a temperature that is considered to be moderately high for tomato fruit set. After an initial burst of respiration during the first stage of hydration at 30 degrees C (>1 h), the respiration rate of pollen of all three categories declined, the decrease being greater in the lots with a low or medium respiratory activity than in the high category. During hydration (10 min after the start of incubation), the addition of succinate or reduced beta-nicotinamide adenine dinucleotide (NADH) to the substrate increased the respiratory rate of slowly-respiring pollen more than that of fast-respiring pollen, but carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and adenosine 5'-diphosphate (ADP) had less effect. After 1-4 h incubation, the respiration rate of the slow- or medium-respiring pollen lots had decreased, but was stimulated by succinate or NADH, and to a lesser degree by ADP. By 7 h, the respiration rate of all pollen lots had declined and was stimulated less by substrate, ADP or CCCP. The oxidation of NADH by tomato pollen contrasts with the failure of other pollen species to utilize this substrate; moreover, a synergistic effect of NADH and succinate was consistently observed. We conclude that the decline in respiration during incubation for up to 4 h at 30 degrees C may reflect a lack of respiratory substrate. After 7 h, however, the decreased response to substrate indicates a loss of mitochondrial integrity or an accumulation of metabolic inhibitors. It is concluded that at 30 degrees C (a moderately high temperature for tomato pollen), the initially high rate of respiration leads to exhaustion of the endogenous respiratory substrates (particularly in pollen with low to medium respiratory activity), but subsequently to ageing and a loss of mitochondrial activity.
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48
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Lenaz G, Genova ML. Mobility and function of Coenzyme Q (ubiquinone) in the mitochondrial respiratory chain. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:563-73. [DOI: 10.1016/j.bbabio.2009.02.019] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 02/23/2009] [Accepted: 02/23/2009] [Indexed: 11/29/2022]
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49
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Sierra-Campos E, Velázquez I, Matuz-Mares D, Villavicencio-Queijeiro A, Pardo JP. Functional properties of the Ustilago maydis alternative oxidase under oxidative stress conditions. Mitochondrion 2009; 9:96-102. [PMID: 19460302 DOI: 10.1016/j.mito.2009.01.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 12/09/2008] [Accepted: 01/05/2009] [Indexed: 11/28/2022]
Abstract
The mitochondrial respiratory chain of Ustilago maydis contains two terminal oxidases, the cytochrome c oxidase (COX) and the alternative oxidase (AOX). To understand the biochemical events that control AOX activity, we studied the regulation and function of AOX under oxidative stress. The activity of this enzyme was increased by both pyruvate (K(05)=2.6 mM) and purine nucleotides (AMP, K(05)=600 microM) in mitochondria using succinate as respiratory substrate. When U.maydis cells were grown in the presence of antimycin A, the amount of AOX in mitochondria was markedly increased and its selectivity towards AMP and pyruvate changed, suggesting that post-translational events may play a role in the regulation of AOX activity under stress conditions. Addition of antimycin A to isolated mitochondria induced the inactivation of AOX, the formation of lipid peroxides and the loss of glutathione from mitochondria. The two last processes are probably related with the time dependent inactivation of AOX, in agreement with the inhibition of the enzyme by tert-butyl hydroperoxide. Our results suggest that the in vivo operation of AOX in U. maydis depends on the mitochondrial antioxidant machinery, including the glutathione linked systems.
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Affiliation(s)
- E Sierra-Campos
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Apartado Postal 70-159, Coyoacán 04510, México DF, México
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50
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Igamberdiev AU, Hill RD. Plant mitochondrial function during anaerobiosis. ANNALS OF BOTANY 2009; 103:259-68. [PMID: 18586697 PMCID: PMC2707300 DOI: 10.1093/aob/mcn100] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 04/29/2008] [Accepted: 05/21/2008] [Indexed: 05/17/2023]
Abstract
BACKGROUND Under hypoxic conditions, plant mitochondria preserve the capacity to oxidize external NADH, NADPH and tricarboxylic acid cycle substrates. Nitrite serves as an alternative electron acceptor at the level of cytochrome oxidase, with possibly complex III and the alternative oxidase also being involved. Nitric oxide is a significant product of the reaction, which has a high affinity for cytochrome c oxidase, inhibiting it. The excess NO is scavenged by hypoxically induced class 1 haemoglobin in the reaction involving ascorbate. SCOPE By using nitrite, mitochondria retain a limited capacity for ATP synthesis. NADH, produced from glycolysis during anaerobiosis and oxidized in the mitochondrial electron transport chain, should shift the composition of metabolites formed during anaerobiosis with increased conversion of pyruvate to alanine and greater involvement of other transamination reactions, such as those involving gamma-aminobutyric acid formation. CONCLUSIONS Anaerobic mitochondrial metabolism may have a more significant role than previously thought in alleviating the effects of anoxia on plant cells. There is a need to re-examine mitochondrial carbon and nitrogen metabolism under anoxia to establish the extent of this involvement.
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Affiliation(s)
- Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St John's, NL, Canada, A1B 3X9
| | - Robert D. Hill
- Department of Plant Science, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2
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