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Xu J, Zhao X, Zhong Y, Qu T, Sun B, Zhang H, Hou C, Zhang Z, Tang X, Wang Y. Acclimation of intertidal macroalgae Ulva prolifera to UVB radiation: the important role of alternative oxidase. BMC PLANT BIOLOGY 2024; 24:143. [PMID: 38413873 PMCID: PMC10900725 DOI: 10.1186/s12870-024-04762-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 01/23/2024] [Indexed: 02/29/2024]
Abstract
BACKGROUND Solar radiation is primarily composed of ultraviolet radiation (UVR, 200 - 400 nm) and photosynthetically active radiation (PAR, 400 - 700 nm). Ultraviolet-B (UVB) radiation accounts for only a small proportion of sunlight, and it is the primary cause of plant photodamage. The use of chlorofluorocarbons (CFCs) as refrigerants caused serious ozone depletion in the 1980s, and this had led to an increase in UVB. Although CFC emissions have significantly decreased in recent years, UVB radiation still remains at a high intensity. UVB radiation increase is an important factor that influences plant physiological processes. Ulva prolifera, a type of macroalga found in the intertidal zone, is intermittently exposed to UVB. Alternative oxidase (AOX) plays an important role in plants under stresses. This research examines the changes in AOX activity and the relationships among AOX, photosynthesis, and reactive oxygen species (ROS) homeostasis in U. prolifera under changes in UVB and photosynthetically active radiation (PAR). RESULTS UVB was the main component of solar radiation impacting the typical intertidal green macroalgae U. prolifera. AOX was found to be important during the process of photosynthesis optimization of U. prolifera due to a synergistic effect with non-photochemical quenching (NPQ) under UVB radiation. AOX and glycolate oxidase (GO) worked together to achieve NADPH homeostasis to achieve photosynthesis optimization under changes in PAR + UVB. The synergism of AOX with superoxide dismutase (SOD) and catalase (CAT) was important during the process of ROS homeostasis under PAR + UVB. CONCLUSIONS AOX plays an important role in the process of photosynthesis optimization and ROS homeostasis in U. prolifera under UVB radiation. This study provides further insights into the response of intertidal macroalgae to solar light changes.
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Grants
- No. LSKJ202203605 Laoshan Laboratory
- Nos. 41906120, 42176204, 41976132, and 41706121 National Natural Science Foundation of China
- Nos. 41906120, 42176204, 41976132, and 41706121 National Natural Science Foundation of China
- Nos. 41906120, 42176204, 41976132, and 41706121 National Natural Science Foundation of China
- Nos. 41906120, 42176204, 41976132, and 41706121 National Natural Science Foundation of China
- Nos. U1806213 and U1606404 NSFC-Shandong Joint Fund
- Nos. U1806213 and U1606404 NSFC-Shandong Joint Fund
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Affiliation(s)
- Jinhui Xu
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
| | - Xinyu Zhao
- Laoshan Laboratory, 1 Wenhai Road, Qingdao, 266237, China.
| | - Yi Zhong
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
| | - Tongfei Qu
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
| | - Baixue Sun
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
| | - Huanxin Zhang
- College of Geography and Environment, Shandong Normal University, 1 Daxue Road, Jinan, 250000, China
| | - Chengzong Hou
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
| | - Zhipeng Zhang
- Tianjin Research Institute for Water Transport Engineering, Ministry of Transport, Tianjin, 300456, China
| | - Xuexi Tang
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, 1 Wenhai Road, Qingdao, 266237, China
| | - Ying Wang
- College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China.
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, 1 Wenhai Road, Qingdao, 266237, China.
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2
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Kuo WH, Small LL, Olsen KM. Variable expression of cyanide detoxification and tolerance genes in cyanogenic and acyanogenic white clover (Trifolium repens). AMERICAN JOURNAL OF BOTANY 2023; 110:e16233. [PMID: 37661820 DOI: 10.1002/ajb2.16233] [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: 05/05/2023] [Revised: 08/04/2023] [Accepted: 08/04/2023] [Indexed: 09/05/2023]
Abstract
PREMISE β-Cyanoalanine synthase (β-CAS) and alternative oxidase (AOX) play important roles in the ability of plants to detoxify and tolerate hydrogen cyanide (HCN). These functions are critical for all plants because HCN is produced at low levels during basic metabolic processes, and especially for cyanogenic species, which release high levels of HCN following tissue damage. However, expression of β-CAS and Aox genes has not been examined in cyanogenic species, nor compared between cyanogenic and acyanogenic genotypes within a species. METHODS We used a natural polymorphism for cyanogenesis in white clover to examine β-CAS and Aox gene expression in relation to cyanogenesis-associated HCN exposure. We identified all β-CAS and Aox gene copies present in the genome, including members of the Aox1, Aox2a, and Aox2d subfamilies previously reported in legumes. Expression levels were compared between cyanogenic and acyanogenic genotypes and between damaged and undamaged leaf tissue. RESULTS β-CAS and Aox2a expression was differentially elevated in cyanogenic genotypes, and tissue damage was not required to induce this increased expression. Aox2d, in contrast, appeared to be upregulated as a generalized wounding response. CONCLUSIONS These findings suggest a heightened constitutive role for HCN detoxification (via elevated β-CAS expression) and HCN-toxicity mitigation (via elevated Aox2a expression) in plants that are capable of cyanogenesis. As such, freezing-induced cyanide autotoxicity is unlikely to be the primary selective factor in the evolution of climate-associated cyanogenesis clines.
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Affiliation(s)
- Wen-Hsi Kuo
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Linda L Small
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Kenneth M Olsen
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
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Garmash EV. Suppression of mitochondrial alternative oxidase can result in upregulation of the ROS scavenging network: some possible mechanisms underlying the compensation effect. PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:43-53. [PMID: 36245276 DOI: 10.1111/plb.13477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Mitochondrial alternative oxidase is an important protein involved in maintaining cellular metabolic and energy balance, especially under stress conditions. AOX genes knockout is aimed at revealing the functions of AOX genes. Under unfavourable conditions, AOX-suppressed plants (mainly based on Arabidopsis AOX1a-knockout lines) usually experience strong oxidative stress. However, a compensation effect, which consists of the absence of AOX1a leading to an increase in defence response mechanisms, concomitant with a decrease in ROS content, has also been demonstrated. This review briefly describes the possible mechanisms underlying the compensation effect upon the suppression of AOX1a. Information about mitochondrial retrograde regulation of AOX is given. The importance of ROS and mitochondrial membrane potential in triggering the signal transmission from mitochondria in the absence of AOX or disturbance of mitochondrial electron transport chain functions is indicated. The few available data on the response of the cell to the absence of AOX at the level of changes in the hormonal balance and the reactions of chloroplasts are presented. The decrease in the relative amount of reduced ascorbate at stable ROS levels as a result of compensation in AOX1a-suppressed plants is proposed as a sign of stress development. Obtaining direct evidence on the mechanisms and signalling pathways involved in AOX modulation in the genome should facilitate a deeper understanding of the role of AOX in the integration of cellular signalling pathways.
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Affiliation(s)
- E V Garmash
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
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Matos IF, Morales LMM, Santana DB, Silva GMC, Gomes MMDA, Ayub RA, Costa JH, de Oliveira JG. Ascorbate synthesis as an alternative electron source for mitochondrial respiration: Possible implications for the plant performance. FRONTIERS IN PLANT SCIENCE 2022; 13:987077. [PMID: 36507441 PMCID: PMC9727407 DOI: 10.3389/fpls.2022.987077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/31/2022] [Indexed: 06/01/2023]
Abstract
The molecule vitamin C, in the chemical form of ascorbic acid (AsA), is known to be essential for the metabolism of humans and animals. Humans do not produce AsA, so they depend on plants as a source of vitamin C for their food. The AsA synthesis pathway occurs partially in the cytosol, but the last oxidation step is physically linked to the respiratory chain of plant mitochondria. This oxidation step is catalyzed by l-galactono-1,4-lactone dehydrogenase (l-GalLDH). This enzyme is not considered a limiting step for AsA production; however, it presents a distinguishing characteristic: the l-GalLDH can introduce electrons directly into the respiratory chain through cytochrome c (Cytc) and therefore can be considered an extramitochondrial electron source that bypasses the phosphorylating Complex III. The use of Cytc as electron acceptor has been debated in terms of its need for AsA synthesis, but little has been said in relation to its impact on the functioning of the respiratory chain. This work seeks to offer a new view about the possible changes that result of the link between AsA synthesis and the mitochondrial respiration. We hypothesized that some physiological alterations related to low AsA may be not only explained by the deficiency of this molecule but also by the changes in the respiratory function. We discussed some findings showing that respiratory mutants contained changes in AsA synthesis. Besides, recent works that also indicate that the excessive electron transport via l-GalLDH enzyme may affect other respiratory pathways. We proposed that Cytc reduction by l-GalLDH may be part of an alternative respiratory pathway that is active during AsA synthesis. Also, it is proposed that possible links of this pathway with other pathways of alternative electron transport in plant mitochondria may exist. The review suggests potential implications of this relationship, particularly for situations of stress. We hypothesized that this pathway of alternative electron input would serve as a strategy for adaptation of plant respiration to changing conditions.
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Affiliation(s)
- Isabelle Faria Matos
- Plant Genetic Breeding Laboratory, Center for Agricultural Sciences and Technologies, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil
| | | | - Diederson Bortolini Santana
- Plant Genetic Breeding Laboratory, Center for Agricultural Sciences and Technologies, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil
| | - Gláucia Michelle Cosme Silva
- Plant Genetic Breeding Laboratory, Center for Agricultural Sciences and Technologies, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil
| | - Mara Menezes de Assis Gomes
- Plant Genetic Breeding Laboratory, Center for Agricultural Sciences and Technologies, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil
| | - Ricardo Antônio Ayub
- Laboratory of Biotechnology Applied to Fruit Growing, Department of Phytotechny and Phytosanitary, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brazil
| | - José Hélio Costa
- Functional Genomics and Bioinformatics, Department of Biochemistry and Molecular Biology, Universidade Federal do Ceará, Fortaleza, CE, Brazil
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), coordinated from Foros de Vale de Figueira, Alentejo, Portugal
| | - Jurandi Gonçalves de Oliveira
- Plant Genetic Breeding Laboratory, Center for Agricultural Sciences and Technologies, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ, Brazil
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Sweetman C, Waterman CD, Wong DC, Day DA, Jenkins CL, Soole KL. Altering the balance between AOX1A and NDB2 expression affects a common set of transcripts in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2022; 13:876843. [PMID: 36466234 PMCID: PMC9716356 DOI: 10.3389/fpls.2022.876843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 10/24/2022] [Indexed: 06/17/2023]
Abstract
Stress-responsive components of the mitochondrial alternative electron transport pathway have the capacity to improve tolerance of plants to abiotic stress, particularly the alternative oxidase AOX1A but also external NAD(P)H dehydrogenases such as NDB2, in Arabidopsis. NDB2 and AOX1A can cooperate to entirely circumvent the classical electron transport chain in Arabidopsis mitochondria. Overexpression of AOX1A or NDB2 alone can have slightly negative impacts on plant growth under optimal conditions, while simultaneous overexpression of NDB2 and AOX1A can reverse these phenotypic effects. We have taken a global transcriptomic approach to better understand the molecular shifts that occur due to overexpression of AOX1A alone and with concomitant overexpression of NDB2. Of the transcripts that were significantly up- or down- regulated in the AOX1A overexpression line compared to wild type (410 and 408, respectively), the majority (372 and 337, respectively) reverted to wild type levels in the dual overexpression line. Several mechanisms for the AOX1A overexpression phenotype are proposed based on the functional classification of these 709 genes, which can be used to guide future experiments. Only 28 genes were uniquely up- or down-regulated when NDB2 was overexpressed in the AOX1A overexpression line. On the other hand, many unique genes were deregulated in the NDB2 knockout line. Furthermore, several changes in transcript abundance seen in the NDB2 knockout line were consistent with changes in the AOX1A overexpression line. The results suggest that an imbalance in AOX1A:NDB2 protein levels caused by under- or over-expression of either component, triggers a common set of transcriptional responses that may be important in mitochondrial redox regulation. The most significant changes were transcripts associated with photosynthesis, secondary metabolism and oxidative stress responses.
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Affiliation(s)
- Crystal Sweetman
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
| | | | - Darren C.J. Wong
- College of Science, Australian National University, Canberra, ACT, Australia
| | - David A. Day
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
| | - Colin L.D. Jenkins
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
| | - Kathleen L. Soole
- College of Science & Engineering, Flinders University, Bedford Park, SA, Australia
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Wen Y, Zhang D. RETRACTED: Alternative oxidase is involved in leaf senescence via regulation of Salicylic acid accumulation in tomato. Biochem Biophys Res Commun 2022; 625:81-86. [PMID: 35952611 DOI: 10.1016/j.bbrc.2022.07.080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 07/20/2022] [Indexed: 11/02/2022]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the corresponding author, Yu Wen, and the Editor-in-Chief. The corresponding author requested retraction, due to multiple self-reported issues and breaches of scientific ethical standards. The Editor-in-Chief no longer has trust in the veracity of the findings in the paper and therefore decided to retract it. This paper was submitted to the journal by Yu Wen without the knowledge or permission of the co-author Dawei Zhang. Authors submitting to the journal warrant that the publication is approved by all authors. As Dawei Zhang did not agree to be a co-author on the paper, this is a clear breach of the submission requirements for the journal, as well a breach of scientific ethical standards. As well as the issue with the authorship, there are problems with the veracity of the data published in the article. Specifically, there is a duplication of Fig 1g and Fig 2a. The corresponding author Yu Wen has indicated that the relevant experiments in the article are inadequate and the conclusions cannot be characterized by physiological data alone, especially in the fourth figure where further relevant molecular experiments need to be designed to refine the conclusion.
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Affiliation(s)
- Yu Wen
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China.
| | - Dawei Zhang
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China.
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7
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Zafari S, Vanlerberghe GC, Igamberdiev AU. The Role of Alternative Oxidase in the Interplay between Nitric Oxide, Reactive Oxygen Species, and Ethylene in Tobacco ( Nicotiana tabacum L.) Plants Incubated under Normoxic and Hypoxic Conditions. Int J Mol Sci 2022; 23:7153. [PMID: 35806157 PMCID: PMC9266549 DOI: 10.3390/ijms23137153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 06/24/2022] [Indexed: 02/05/2023] Open
Abstract
The transgenic tobacco (Nicotiana tabacum L.) plants with the modified levels of alternative oxidase (AOX) were used to evaluate the physiological roles of AOX in regulating nitro-oxidative stress and metabolic changes after exposing plants to hypoxia for 6 h. Under normoxia, AOX expression resulted in the decrease of nitric oxide (NO) levels and of the rate of protein S-nitrosylation, while under hypoxia, AOX overexpressors exhibited higher NO and S-nitrosylation levels than knockdowns. AOX expression was essential in avoiding hypoxia-induced superoxide and H2O2 levels, and this was achieved via higher activities of catalase and glutathione reductase and the reduced expression of respiratory burst oxidase homolog (Rboh) in overexpressors as compared to knockdowns. The AOX overexpressing lines accumulated less pyruvate and exhibited the increased transcript and activity levels of pyruvate decarboxylase and alcohol dehydrogenase under hypoxia. This suggests that AOX contributes to the energy state of hypoxic tissues by stimulating the increase of pyruvate flow into fermentation pathways. Ethylene biosynthesis genes encoding 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, ACC oxidase, and ethylene-responsive factors (ERFs) were induced during hypoxia and correlated with AOX and NO levels. We conclude that AOX controls the interaction of NO, reactive oxygen species, and ethylene, triggering a coordinated downstream defensive response against hypoxia.
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Affiliation(s)
- Somaieh Zafari
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
| | - Greg C. Vanlerberghe
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada;
- Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada
| | - Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
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8
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Arce RC, Carrillo N, Pierella Karlusich JJ. The chloroplast redox-responsive transcriptome of solanaceous plants reveals significant nuclear gene regulatory motifs associated to stress acclimation. PLANT MOLECULAR BIOLOGY 2022; 108:513-530. [PMID: 35044587 DOI: 10.1007/s11103-022-01240-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
Transcriptomes of solanaceous plants expressing a plastid-targeted antioxidant protein were analysed to identify chloroplast redox networks modulating the expression of nuclear genes associated with stress acclimation. Plastid functions depend on the coordinated expression of nuclear genes, many of them associated to developmental and stress response pathways. Plastid-generated signals mediate this coordination via retrograde signaling, which includes sensing of chloroplast redox state and levels of reactive oxygen species (ROS), although it remains a poorly understood process. Chloroplast redox poise and ROS build-up can be modified by recombinant expression of a plastid-targeted antioxidant protein, i.e., cyanobacterial flavodoxin, with the resulting plants displaying increased tolerance to multiple environmental challenges. Here we analysed the transcriptomes of these flavodoxin-expressing plants to study the coordinated transcriptional responses of the nucleus to the chloroplast redox status and ROS levels during normal growth and stress responses (drought or biotic stress) in tobacco and potato, members of the economically important Solanaceae family. We compared their transcriptomes against those from stressed and mutant plants accumulating ROS in different subcellular compartments and found distinct ROS-related imprints modulated by flavodoxin expression and/or stress. By introducing our datasets in a large-scale interaction network, we identified transcriptional factors related to ROS and stress responses potentially involved in flavodoxin-associated signaling. Finally, we discovered identical cis elements in the promoters of many genes that respond to flavodoxin in the same direction as in wild-type plants under stress, suggesting a priming effect of flavodoxin before stress manifestation. The results provide a genome-wide picture illustrating the relevance of chloroplast redox status on biotic and abiotic stress responses and suggest new cis and trans targets to generate stress-tolerant solanaceous crops.
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Affiliation(s)
- Rocío C Arce
- Instituto de Biología Molecular y Celular de Rosario (IBR-UNR/CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), 2000, Rosario, Argentina
| | - Néstor Carrillo
- Instituto de Biología Molecular y Celular de Rosario (IBR-UNR/CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), 2000, Rosario, Argentina
| | - Juan J Pierella Karlusich
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, 75005, Paris, France.
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Arnholdt-Schmitt B, Mohanapriya G, Bharadwaj R, Noceda C, Macedo ES, Sathishkumar R, Gupta KJ, Sircar D, Kumar SR, Srivastava S, Adholeya A, Thiers KL, Aziz S, Velada I, Oliveira M, Quaresma P, Achra A, Gupta N, Kumar A, Costa JH. From Plant Survival Under Severe Stress to Anti-Viral Human Defense - A Perspective That Calls for Common Efforts. Front Immunol 2021; 12:673723. [PMID: 34211468 PMCID: PMC8240590 DOI: 10.3389/fimmu.2021.673723] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/13/2021] [Indexed: 12/11/2022] Open
Abstract
Reprogramming of primary virus-infected cells is the critical step that turns viral attacks harmful to humans by initiating super-spreading at cell, organism and population levels. To develop early anti-viral therapies and proactive administration, it is important to understand the very first steps of this process. Plant somatic embryogenesis (SE) is the earliest and most studied model for de novo programming upon severe stress that, in contrast to virus attacks, promotes individual cell and organism survival. We argued that transcript level profiles of target genes established from in vitro SE induction as reference compared to virus-induced profiles can identify differential virus traits that link to harmful reprogramming. To validate this hypothesis, we selected a standard set of genes named 'ReprogVirus'. This approach was recently applied and published. It resulted in identifying 'CoV-MAC-TED', a complex trait that is promising to support combating SARS-CoV-2-induced cell reprogramming in primary infected nose and mouth cells. In this perspective, we aim to explain the rationale of our scientific approach. We are highlighting relevant background knowledge on SE, emphasize the role of alternative oxidase in plant reprogramming and resilience as a learning tool for designing human virus-defense strategies and, present the list of selected genes. As an outlook, we announce wider data collection in a 'ReprogVirus Platform' to support anti-viral strategy design through common efforts.
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Affiliation(s)
- Birgit Arnholdt-Schmitt
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Functional Genomics and Bioinformatics Group, Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
| | - Gunasekaran Mohanapriya
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, India
| | - Revuru Bharadwaj
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, India
| | - Carlos Noceda
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Cell and Molecular Biotechnology of Plants (BIOCEMP)/Industrial Biotechnology and Bioproducts, Departamento de Ciencias de la Vida y de la Agricultura, Universidad de las Fuerzas Armadas-ESPE, Sangolquí, Ecuador
| | - Elisete Santos Macedo
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
| | - Ramalingam Sathishkumar
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, India
| | - Kapuganti Jagadis Gupta
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | - Debabrata Sircar
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Department of Biotechnology, Indian Institute of Technology, Roorkee, Uttarakhand, India
| | - Sarma Rajeev Kumar
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, India
| | - Shivani Srivastava
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Centre for Mycorrhizal Research, Sustainable Agriculture Division, The Energy and Resources Institute (TERI), TERI Gram, Gual Pahari, Gurugram, India
| | - Alok Adholeya
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Centre for Mycorrhizal Research, Sustainable Agriculture Division, The Energy and Resources Institute (TERI), TERI Gram, Gual Pahari, Gurugram, India
| | - KarineLeitão Lima Thiers
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Functional Genomics and Bioinformatics Group, Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
| | - Shahid Aziz
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Functional Genomics and Bioinformatics Group, Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
| | - Isabel Velada
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- MED—Mediterranean Institute for Agriculture, Environment and Development, Instituto de Investigação e Formação Avançada, Universidade de Évora, Évora, Portugal
| | - Manuela Oliveira
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Department of Mathematics and CIMA - Center for Research on Mathematics and its Applications, Universidade de Évora, Évora, Portugal
| | - Paulo Quaresma
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- NOVA LINCS – Laboratory for Informatics and Computer Science, University of Évora, Évora, Portugal
| | - Arvind Achra
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Department of Microbiology, Atal Bihari Vajpayee Institute of Medical Sciences & Dr Ram Manohar Lohia Hospital, New Delhi, India
| | - Nidhi Gupta
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
| | - Ashwani Kumar
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Hargovind Khorana Chair, Jayoti Vidyapeeth Womens University, Jaipur, India
| | - José Hélio Costa
- Non-Institutional Competence Focus (NICFocus) ‘Functional Cell Reprogramming and Organism Plasticity’ (FunCROP), Coordinated from Foros de Vale de Figueira, Alentejo, Portugal
- Functional Genomics and Bioinformatics Group, Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
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10
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Turnell BR, Kumpitsch L, Reinhardt K. Production and scavenging of reactive oxygen species both affect reproductive success in male and female Drosophila melanogaster. Biogerontology 2021; 22:379-396. [PMID: 33903991 PMCID: PMC8266701 DOI: 10.1007/s10522-021-09922-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/30/2021] [Indexed: 10/27/2022]
Abstract
Sperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.
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Affiliation(s)
- Biz R Turnell
- Applied Zoology, Faculty Biology, Technische Universität Dresden, 01069, Dresden, Germany.
| | - Luisa Kumpitsch
- Applied Zoology, Faculty Biology, Technische Universität Dresden, 01069, Dresden, Germany
| | - Klaus Reinhardt
- Applied Zoology, Faculty Biology, Technische Universität Dresden, 01069, Dresden, Germany
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11
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Garmash EV, Belykh ES, Velegzhaninov IO. The gene expression profiles of mitochondrial respiratory components in Arabidopsis plants with differing amounts of ALTERNATIVE OXIDASE1a under high intensity light. PLANT SIGNALING & BEHAVIOR 2021; 16:1864962. [PMID: 33369529 PMCID: PMC7889022 DOI: 10.1080/15592324.2020.1864962] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We compared the expression of mitochondrial alternative oxidase (AOX) and other non-phosphorylating respiratory components (NPhPs) in wild type and AOX1a transgenic Arabidopsis thaliana following short-term transfer of plants to higher irradiance conditions to gain more insight into the mechanisms of AOX functioning under light. The AOX1a overexpressing line (XX-2) showed the highest amount of AOX1a transcripts and AOX1A synthesis during the entire experiment, and many NPhPs genes were down-regulated after 6-8 h under the higher light conditions. Antisense AS-12 plants displayed a compensatory effect, typically after 8 h of exposure to higher irradiance, by up-regulating their expression of the majority of genes encoding AOX and other respiratory components. In addition, AS-12 plants displayed 'overcompensation effects' prior to their transfer to high light conditions, i.e., they showed a higher expression level of certain genes. As a result, the ROS content in AS-12, as in XX-2, was consistently lower than in the wild type. All NPhPs genes share, in common with AOX1a, light- and stress-related cis-acting regulatory elements (CAREs) in their promoters. However, the expression of respiratory genes does not always depend on the level of AOX1a expression. This suggests the presence of multiple combinations of signaling pathways in gene induction. Based on our results, we outline possible directions for future research.
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Affiliation(s)
- Elena V. Garmash
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
- CONTACT Elena V. Garmash Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Elena S. Belykh
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Ilya O. Velegzhaninov
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
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12
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Garmash EV. Role of mitochondrial alternative oxidase in the regulation of cellular homeostasis during development of photosynthetic function in greening leaves. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:221-228. [PMID: 33190385 DOI: 10.1111/plb.13217] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/08/2020] [Indexed: 05/27/2023]
Abstract
Here, recent publications on the role of mitochondrial non-phosphorylating pathways (NPhPs) in the electron transport chain during the de-etiolation of wheat leaves are reviewed. Among NPhPs, the alternative oxidase (AOX) pathway is the most effective pathway in maintaining cellular redox and energy balance, especially under stress conditions, including light stress. AOX is considered to dissipate excess reductants produced in the chloroplasts, and thereby prevent photooxidation. However, when etiolated wheat plants were exposed to a physiologically relevant light level, AOX was rapidly induced and increased, although the etioplasts did not produce excess reductants and have their own strong photoprotective mechanisms. The present study provides further insights into the role of AOX in greening cells and highlights the importance of AOX in the integration of cellular signalling pathways.
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Affiliation(s)
- E V Garmash
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, 167982, Russian Federation
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13
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Li CZ, Yang L, Lin YJ, Zhang H, Rad S, Yu XZ. Assimilation of exogenous cyanide cross talk in Oryza sativa L. to the key nodes in nitrogen metabolism. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:1552-1564. [PMID: 32803565 DOI: 10.1007/s10646-020-02265-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
Exogenous cyanide (CN-) effects on nitrogen (N) uptake, transport, and assimilation in rice seedlings were investigated at the biochemical and molecular levels. Seedlings were treated with either a 2-d or 4-d supply of potassium cyanide (KCN) in the nutrient solution containing nitrate (NO3-) or ammonium (NH4+). Although a KCN-induced increase was recorded in the activity of β-cyanoalanine synthase (β-CAS) in rice tissues of both NH4+-fed and NO3--fed seedlings, the former showed a significantly greater assimilation rate for CN- than the latter. The addition of KCN decreased NO3- uptake and assimilation, whereas a negligible impact was observed in NH4+ treatments. Enzymatic assays showed a marked activities enhancement of glutamine synthetase (GS), glutamate synthase (GOGAT), and glutamate dehydrogenase (GDH) in NH4+-fed seedlings after KCN exposure. Similarly, the rises occurring in nitrate reductase (NR) and GDH activity in NO3--fed seedlings were also detected after 2-d exposure to KCN, whereas a significant reduction of GS and GOGAT activities was determined. The results suggest that although exogenous KCN at moderate or high concentrations caused repressively effects on biomass growth of both NH4+-fed and NO3--fed rice seedlings, the nontoxic concentration of KCN supplied can serve as a supplemental N source in plant nutrition and N metabolism.
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Affiliation(s)
- Cheng-Zhi Li
- College of Environmental Science & Engineering, Guilin University of Technology, Guilin, 541004, People's Republic of China
| | - Li Yang
- College of Environmental Science & Engineering, Guilin University of Technology, Guilin, 541004, People's Republic of China
| | - Yu-Juan Lin
- College of Environmental Science & Engineering, Guilin University of Technology, Guilin, 541004, People's Republic of China
| | - Hua Zhang
- College of Environmental Science & Engineering, Guilin University of Technology, Guilin, 541004, People's Republic of China
| | - Saeed Rad
- College of Environmental Science & Engineering, Guilin University of Technology, Guilin, 541004, People's Republic of China
| | - Xiao-Zhang Yu
- College of Environmental Science & Engineering, Guilin University of Technology, Guilin, 541004, People's Republic of China.
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14
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Analin B, Mohanan A, Bakka K, Challabathula D. Cytochrome oxidase and alternative oxidase pathways of mitochondrial electron transport chain are important for the photosynthetic performance of pea plants under salinity stress conditions. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 154:248-259. [PMID: 32570012 DOI: 10.1016/j.plaphy.2020.05.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
The flexible plant mitochondrial electron transport chain with cytochrome c oxidase (COX) and alternative oxidase (AOX) pathways is known to be modulated by abiotic stress conditions. The effect of salinity stress on the mitochondrial electron transport chain and the importance of COX and AOX pathways for optimization of photosynthesis under salinity stress conditions is not clearly understood. In the current study, importance of COX and AOX pathways for photosynthetic performance of pea plants (Pisum sativum L. Pea Arkel cv) was analysed by using the mitochondrial electron transport chain inhibitors Antimycin A (AA) and salicylhydroxamic acid (SHAM) which restrict the electron flow through COX and AOX pathways respectively. Salinity stress resulted in decreased CO2 assimilation rates, leaf stomatal conductance, transpiration and leaf intercellular CO2 concentration in a stress dependent manner. Superimposition of leaves of salt stressed plants with AA and SHAM caused cellular H2O2 and O2- accumulation along with cell death. Additionally, aggravation in decrease of CO2 assimilation rates, leaf stomatal conductance, transpiration and leaf intercellular CO2 concentration upon superimposition with AA and SHAM during salinity stress suggests the importance of mitochondrial oxidative electron transport for photosynthesis. Increased expression of AOX1a and AOX2 transcripts along with AOX protein levels indicated up regulation of AOX pathway in leaves during salinity stress. Chlorophyll fluorescence measurements revealed enhanced damage to Photosystem (PS) II in the presence of AA and SHAM during salinity stress. Results suggested the beneficial role of COX and AOX pathways for optimal photosynthetic performance in pea leaves during salinity stress conditions.
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Affiliation(s)
- Benedict Analin
- Plant Molecular Stress Physiology Research Group, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India
| | - Akhil Mohanan
- Plant Molecular Stress Physiology Research Group, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India
| | - Kavya Bakka
- Plant Molecular Stress Physiology Research Group, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India
| | - Dinakar Challabathula
- Plant Molecular Stress Physiology Research Group, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India.
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15
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Burke R, Schwarze J, Sherwood OL, Jnaid Y, McCabe PF, Kacprzyk J. Stressed to Death: The Role of Transcription Factors in Plant Programmed Cell Death Induced by Abiotic and Biotic Stimuli. FRONTIERS IN PLANT SCIENCE 2020; 11:1235. [PMID: 32903426 PMCID: PMC7434935 DOI: 10.3389/fpls.2020.01235] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/28/2020] [Indexed: 05/20/2023]
Abstract
Programmed cell death (PCD) is a genetically controlled pathway that plants can use to selectively eliminate redundant or damaged cells. In addition to its fundamental role in plant development, PCD can often be activated as an essential defense response when dealing with biotic and abiotic stresses. For example, localized, tightly controlled PCD can promote plant survival by restricting pathogen growth, driving the development of morphological traits for stress tolerance such as aerenchyma, or triggering systemic pro-survival responses. Relatively little is known about the molecular control of this essential process in plants, especially in comparison to well-described cell death models in animals. However, the networks orchestrating transcriptional regulation of plant PCD are emerging. Transcription factors (TFs) regulate the clusters of stimuli inducible genes and play a fundamental role in plant responses, such as PCD, to abiotic and biotic stresses. Here, we discuss the roles of different classes of transcription factors, including members of NAC, ERF and WRKY families, in cell fate regulation in response to environmental stresses. The role of TFs in stress-induced mitochondrial retrograde signaling is also reviewed in the context of life-and-death decisions of the plant cell and future research directions for further elucidation of TF-mediated control of stress-induced PCD events are proposed. An increased understanding of these complex signaling networks will inform and facilitate future breeding strategies to increase crop tolerance to disease and/or abiotic stresses.
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Affiliation(s)
| | | | | | | | | | - Joanna Kacprzyk
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
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16
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Emami H, Kumar A, Kempken F. Transcriptomic analysis of poco1, a mitochondrial pentatricopeptide repeat protein mutant in Arabidopsis thaliana. BMC PLANT BIOLOGY 2020; 20:209. [PMID: 32397956 PMCID: PMC7216612 DOI: 10.1186/s12870-020-02418-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 04/29/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Flowering is a crucial stage during plant development. Plants may respond to unfavorable conditions by accelerating reproductive processes like flowering. In a recent study, we showed that PRECOCIOUS1 (POCO1) is a mitochondrial pentatricopeptide repeat (PPR) protein involved in flowering time and abscisic acid (ABA) signaling in Arabidopsis thaliana. Here, we use RNA-seq data to investigate global gene expression alteration in the poco1 mutant. RESULTS RNA-seq analysis was performed during different developmental stages for wild-type and poco1 plants. The most profound differences in gene expression were found when wild-type and poco1 plants of the same developmental stage were compared. Coverage analysis confirmed the T-DNA insertion in POCO1, which was concomitant with truncated transcripts. Many biological processes were found to be enriched. Several flowering-related genes such as FLOWERING LOCUS T (FT), which may be involved in the early-flowering phenotype of poco1, were differentially regulated. Numerous ABA-associated genes, including the core components of ABA signaling such as ABA receptors, protein phosphatases, protein kinases, and ABA-responsive element (ABRE) binding proteins (AREBs)/ABRE-binding factors (ABFs) as well as important genes for stomatal function, were mostly down-regulated in poco1. Drought and oxidative stress-related genes, including ABA-induced stress genes, were differentially regulated. RNA-seq analysis also uncovered differentially regulated genes encoding various classes of transcription factors and genes involved in cellular signaling. Furthermore, the expression of stress-associated nuclear genes encoding mitochondrial proteins (NGEMPs) was found to be altered in poco1. Redox-related genes were affected, suggesting that the redox state in poco1 might be altered. CONCLUSION The identification of various enriched biological processes indicates that complex regulatory mechanisms underlie poco1 development. Differentially regulated genes associated with flowering may contribute to the early-flowering phenotype of poco1. Our data suggest the involvement of POCO1 in the early ABA signaling process. The down-regulation of many ABA-related genes suggests an association of poco1 mutation with the ABA signaling deficiency. This condition further affects the expression of many stress-related, especially drought-associated genes in poco1, consistent with the drought sensitivity of poco1. poco1 mutation also affects the expression of genes associated with the cellular regulation, redox, and mitochondrial perturbation.
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Affiliation(s)
- Hossein Emami
- Department of Botany, Christian-Albrechts-University, Olshausenstr. 40, 24098, Kiel, Germany
| | - Abhishek Kumar
- Present address: Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
- Present address: Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, 576104, India
| | - Frank Kempken
- Department of Botany, Christian-Albrechts-University, Olshausenstr. 40, 24098, Kiel, Germany.
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17
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Vanlerberghe GC, Dahal K, Alber NA, Chadee A. Photosynthesis, respiration and growth: A carbon and energy balancing act for alternative oxidase. Mitochondrion 2020; 52:197-211. [PMID: 32278748 DOI: 10.1016/j.mito.2020.04.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/28/2020] [Accepted: 04/06/2020] [Indexed: 12/26/2022]
Abstract
This review summarizes knowledge of alternative oxidase, a mitochondrial electron transport chain component that lowers the ATP yield of plant respiration. Analysis of mutant and transgenic plants has established that alternative oxidase activity supports leaf photosynthesis. The interaction of alternative oxidase respiration with chloroplast metabolism is important under conditions that challenge energy and/or carbon balance in the photosynthetic cell. Under such conditions, alternative oxidase provides an extra-chloroplastic means to optimize the status of chloroplast energy pools (ATP, NADPH) and to manage cellular carbohydrate pools in response to changing rates of carbon fixation and carbon demand for growth and maintenance. Transcriptional and post-translational mechanisms ensure that alternative oxidase can respond effectively when carbon and energy balance are being challenged. This function appears particularly significant under abiotic stress conditions such as water deficit, high salinity, or temperature extremes. Under such conditions, alternative oxidase respiration positively affects growth and stress tolerance, despite it lowering the energy yield and carbon use efficiency of respiration. In part, this beneficial effect relates to the ability of alternative oxidase respiration to prevent excessive reactive oxygen species generation in both mitochondria and chloroplasts. Recent evidence suggests that alternative oxidase respiration is an interesting target for crop improvement.
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Affiliation(s)
- Greg C Vanlerberghe
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C1A4, Canada.
| | - Keshav Dahal
- Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, 850 Lincoln Road, P.O. Box 20280, Fredericton, New Brunswick E3B4Z7, Canada
| | - Nicole A Alber
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C1A4, Canada
| | - Avesh Chadee
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C1A4, Canada
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18
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Lin YJ, Yu XZ, Li YH, Yang L. Inhibition of the mitochondrial respiratory components (Complex I and Complex III) as stimuli to induce oxidative damage in Oryza sativa L. under thiocyanate exposure. CHEMOSPHERE 2020; 243:125472. [PMID: 31995896 DOI: 10.1016/j.chemosphere.2019.125472] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/22/2019] [Accepted: 11/24/2019] [Indexed: 05/24/2023]
Abstract
Repression of the electron transport in mitochondria can result in an increase of reactive oxygen species (ROS) in plant cells. This study was to clarify inhibition of the mitochondrial respiratory components (Complex I and Complex III) as stimuli to induce oxidative damage in Oryza sativa L. under exogenous SCN- exposure with special emphasis on lipid peroxidation, protein modification, and DNA damage at the biochemical and molecular levels. Our results showed that enzymatic activity and gene expression of cytochrome c reductase (Complex III) in roots and shoots of rice seedlings were significantly repressed by SCN- exposure, where significant inhibition of NADH dehydrogenase (Complex I) was only detected in shoots, suggesting that Complex III was the main target attacked by SCN- ligand in rice roots, and both components were arrested in shoots. ROS analysis in tissues indicated that SCN- exposure caused significant accumulation of H2O2 and O2-•, increased malondialdehyde (MDA) and carbonyl content in rice materials in a dose-dependent manner. Similarly, a remarkable elevation of electrolyte leakage was observed in rice tissue samples. The comet assay indicated a positive correlation between DNA damage and external SCN- exposure. In conclusion, oxidative burst generated from the inhibitions of the electron transport in mitochondria in rice seedlings under SCN- exposure can cause lipid peroxidation, protein modification and DNA damage, eventually decreasing fresh weight of rice seedlings.
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Affiliation(s)
- Yu-Juan Lin
- College of Environmental Science & Engineering, Guilin University of Technology, Guilin, 541004, People's Republic of China
| | - Xiao-Zhang Yu
- College of Environmental Science & Engineering, Guilin University of Technology, Guilin, 541004, People's Republic of China; Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin, 541004, People's Republic of China.
| | - Yan-Hong Li
- College of Environmental Science & Engineering, Guilin University of Technology, Guilin, 541004, People's Republic of China
| | - Li Yang
- College of Environmental Science & Engineering, Guilin University of Technology, Guilin, 541004, People's Republic of China
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19
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Garmash EV, Velegzhaninov IO, Ermolina KV, Rybak AV, Malyshev RV. Altered levels of AOX1a expression result in changes in metabolic pathways in Arabidopsis thaliana plants acclimated to low dose rates of ultraviolet B radiation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 291:110332. [PMID: 31928662 DOI: 10.1016/j.plantsci.2019.110332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/28/2019] [Accepted: 11/02/2019] [Indexed: 05/27/2023]
Abstract
UV-B is a damaging component of solar radiation that inevitably reaches the Earth's surface. Plants have developed response mechanisms to adapt to UVB exposure. The alternative oxidase (AOX) catalyzes the ATP-uncoupling cyanide-resistant alternative pathway (AP) in plant mitochondria and is thought to be an important part of the cellular defense network under stress conditions. This study aimed to unravel the poorly understood functional significance of AOX1a induction in Arabidopsis thaliana leaves exposed to ecologically relevant doses of UVB radiation, by comparing wild-type (WT) plants with plants with modified expression of the AOX1a gene, either downregulated by antisense (AS-12) or overexpressed (XX-2). UVB exposure resulted in a phenotypic difference between lines. AOX1a overexpression resulted in the highest induction of AOX1A synthesis and MnSOD activity, and the lowest ROS level without pronounced changes in the phenotype relative to other genotypes. In AS-12 plants, expression of the majority of the genes encoding AOX was detected, other non-phosphorylating pathway components and antioxidant enzymes increased along with anthocyanin accumulation in leaves, and the ROS content was lower than in the WT. In addition to the expected AOX1 protein size (34 kDa), an AOX1 30 kDa band appeared under UVB exposure in all genotypes. However, in AS-12, the alterations in the transcript level and in the abundance of AOX1 protein isoforms induced by UVB could not fully functionally compensate for the lack of AOX1A. This was confirmed by the observed low AP capacity and increased levels of the oxidized form of ascorbate. These results highlight the importance of AOX in plant response to UVB for the control of a balanced metabolism, and indicate that AOX1a plays a key role in the regulation of the stress response.
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Affiliation(s)
- Elena V Garmash
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia.
| | - Ilya O Velegzhaninov
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Ksenia V Ermolina
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Anna V Rybak
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Ruslan V Malyshev
- Institute of Biology, Komi Scientific Centre, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
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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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Alternative Pathway is Involved in Nitric Oxide-Enhanced Tolerance to Cadmium Stress in Barley Roots. PLANTS 2019; 8:plants8120557. [PMID: 31795459 PMCID: PMC6963264 DOI: 10.3390/plants8120557] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/13/2019] [Accepted: 11/25/2019] [Indexed: 12/27/2022]
Abstract
Alternative pathway (AP) has been widely accepted to be involved in enhancing tolerance to various environmental stresses. In this study, the role of AP in response to cadmium (Cd) stress in two barley varieties, highland barley (Kunlun14) and barley (Ganpi6), was investigated. Results showed that the malondialdehyde (MDA) content and electrolyte leakage (EL) level under Cd stress increased in two barley varieties. The expressions of alternative oxidase (AOX) genes (mainly AOX1a), AP capacity (Valt), and AOX protein amount were clearly induced more in Kunlun14 under Cd stress, and these parameters were further enhanced by applying sodium nitroprussid (SNP, a NO donor). Moreover, H2O2 and O2− contents were raised in the Cd-treated roots of two barley varieties, but they were markedly relieved by exogenous SNP. However, this mitigating effect was aggravated by salicylhydroxamic acid (SHAM, an AOX inhibitor), suggesting that AP contributes to NO-enhanced Cd stress tolerance. Further study demonstrated that the effect of SHAM application on reactive oxygen species (ROS)-related scavenging enzymes and antioxidants was minimal. These observations showed that AP exerts an indispensable function in NO-enhanced Cd stress tolerance in two barley varieties. AP was mainly responsible for regulating the ROS accumulation to maintain the homeostasis of redox state.
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22
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Murik O, Tirichine L, Prihoda J, Thomas Y, Araújo WL, Allen AE, Fernie AR, Bowler C. Downregulation of mitochondrial alternative oxidase affects chloroplast function, redox status and stress response in a marine diatom. THE NEW PHYTOLOGIST 2019; 221:1303-1316. [PMID: 30216452 DOI: 10.1111/nph.15479] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 09/03/2018] [Indexed: 05/20/2023]
Abstract
Diatom dominance in contemporary aquatic environments indicates that they have developed unique and effective mechanisms to cope with the rapid and considerable fluctuations that characterize these environments. In view of their evolutionary history from a secondary endosymbiosis, inter-organellar regulation of biochemical activities may be of particular relevance. Diatom mitochondrial alternative oxidase (AOX) is believed to play a significant role in supplying chloroplasts with ATP produced in the mitochondria. Using the model diatom Phaeodactylum tricornutum we generated AOX knockdown lines, and followed sensitivity to stressors, photosynthesis and transcriptome and metabolome profiles of wild-type and knockdown lines. We show here that expression of the AOX gene is upregulated by various stresses including H2 O2 , heat, high light illumination, and iron or nitrogen limitation. AOX knockdown results in hypersensitivity to stress. Knockdown lines also show significantly reduced photosynthetic rates and their chloroplasts are more oxidized. Comparisons of transcriptome and metabolome profiles suggest a strong impact of AOX activity on gene expression, which is carried through to the level of the metabolome. Our data provide evidence for the involvement of mitochondrial AOX in processes central to the cell biology of diatoms, revealing that cross-talk between mitochondria and chloroplasts is crucial for maintaining sensitivity to changing environments.
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Affiliation(s)
- Omer Murik
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
| | - Leila Tirichine
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
| | - Judit Prihoda
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
| | - Yann Thomas
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
| | - Wagner L Araújo
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Andrew E Allen
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA, 92037, USA
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, 92037, USA
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Chris Bowler
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
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Zhu T, Zou L, Li Y, Yao X, Xu F, Deng X, Zhang D, Lin H. Mitochondrial alternative oxidase-dependent autophagy involved in ethylene-mediated drought tolerance in Solanum lycopersicum. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:2063-2076. [PMID: 29729068 PMCID: PMC6230944 DOI: 10.1111/pbi.12939] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 04/01/2018] [Accepted: 04/04/2018] [Indexed: 05/02/2023]
Abstract
Mitochondrial alternative oxidase (AOX) is involved in a large number of plant physiological processes, such as growth, development and stress responses; however, the exact role of AOX in response to drought remains unclear. In our study, we provide solid evidences that the activated AOX capacity positively involved in ethylene-induced drought tolerance, in tomato (Solanum lycopersicum), accompanied by the changing level of hydrogen peroxide (H2 O2 ) and autophagy. In AOX1a-RNAi plants, the ethylene-induced drought tolerance was aggravated and associated with decreasing level of autophagy. The H2 O2 level was relatively higher in AOX1a-RNAi plants, whereas it was lower in AOX1a-overexpressing (35S-AOX1a-OE) plants after 1-(aminocarbonyl)-1-cyclopropanecarboxylic acid (ACC) pretreatment in the 14th day under drought stress. Interestingly, the accumulation of autophagosome was accompanied by the changing level of reactive oxygen species (ROS) in AOX transgenic tomato under drought stress whether or not pretreated with ACC. Pharmacological scavenging of H2 O2 accumulation in AOX1a-RNAi (aox19) stimulated autophagy acceleration under drought stress, and it seems that AOX-dependent ROS signalling is critical in triggering autophagy. Lower levels of ROS signalling positively induce autophagy activity, whereas higher ROS level would lead to rapid programmed cell death (PCD), especially in ethylene-mediated drought tolerance. Moreover, ethylene-induced autophagy during drought stress also can be through ERF5 binding to the promoters of ATG8d and ATG18h. These results demonstrated that AOX plays an essential role in ethylene-induced drought tolerance and also played important roles in mediating autophagy generation via balancing ROS level.
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Affiliation(s)
- Tong Zhu
- Key Laboratory of Bio‐Resources and Eco‐Environment of Ministry of EducationCollege of Life SciencesSichuan UniversityChengduSichuanChina
| | - Lijuan Zou
- Life Science and Technology College and Ecological Security and Protection Key Laboratory of Sichuan ProvinceMianyang Normal UniversityMianyangChina
| | - Yan Li
- Key Laboratory of Bio‐Resources and Eco‐Environment of Ministry of EducationCollege of Life SciencesSichuan UniversityChengduSichuanChina
| | - Xiuhong Yao
- Key Laboratory of Bio‐Resources and Eco‐Environment of Ministry of EducationCollege of Life SciencesSichuan UniversityChengduSichuanChina
| | - Fei Xu
- Life Science and BiotechnologyWuhan Bioengineering InstituteWuhanChina
| | - Xingguang Deng
- Key Laboratory of Bio‐Resources and Eco‐Environment of Ministry of EducationCollege of Life SciencesSichuan UniversityChengduSichuanChina
| | - Dawei Zhang
- Key Laboratory of Bio‐Resources and Eco‐Environment of Ministry of EducationCollege of Life SciencesSichuan UniversityChengduSichuanChina
| | - Honghui Lin
- Key Laboratory of Bio‐Resources and Eco‐Environment of Ministry of EducationCollege of Life SciencesSichuan UniversityChengduSichuanChina
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Ding CQ, Ng S, Wang L, Wang YC, Li NN, Hao XY, Zeng JM, Wang XC, Yang YJ. Genome-wide identification and characterization of ALTERNATIVE OXIDASE genes and their response under abiotic stresses in Camellia sinensis (L.) O. Kuntze. PLANTA 2018; 248:1231-1247. [PMID: 30097722 DOI: 10.1007/s00425-018-2974-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 08/05/2018] [Indexed: 06/08/2023]
Abstract
Four typical ALTERNATIVE OXIDASE genes have been identified in tea plants, and their sequence features and gene expression profiles have provided useful information for further studies on function and regulation. Alternative oxidase (AOX) is a terminal oxidase located in the respiratory electron transport chain. AOX catalyzes the oxidation of quinol and the reduction of oxygen into water. In this study, a genome-wide search and subsequent DNA cloning were performed to identify and characterize AOX genes in tea plant (Camellia sinensis (L.) O. Kuntze cv. Longjing43). Our results showed that tea plant possesses four AOX genes, i.e., CsAOX1a, CsAOX1d, CsAOX2a and CsAOX2b. Gene structure and protein sequence analyses revealed that all CsAOXs share a four-exon/three-intron structure with highly conserved regions and amino acid residues, which are necessary for AOX secondary structures, catalytic activities and post-translational regulations. All CsAOX were shown to localize in mitochondria using the green fluorescent protein (GFP)-targeting assay. Both CsAOX1a and CsAOX1d were induced by cold, salt and drought stresses, and with different expression patterns in young and mature leaves. Reactive oxygen species (ROS) accumulated strongly after 72 and 96 h cold treatments in both young and mature leaves, while the polyphenol and total catechin decreased significantly only in mature leaves. In comparison to AtAOX1a in Arabidopsis thaliana, CsAOX1a lost almost all of the stress-responsive cis-acting regulatory elements in its promoter region (1500 bp upstream), but possesses a flavonoid biosynthesis-related MBSII cis-acting regulatory element. These results suggest a link between CsAOX1a function and the metabolism of some secondary metabolites in tea plant. Our studies provide a basis for the further elucidation of the biological function and regulation of the AOX pathway in tea plants.
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Affiliation(s)
- Chang-Qing Ding
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China
| | - Sophia Ng
- ARC Centre of Excellence Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
- Institut de Biosciences et Biotechnologies, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Cadarache, 13108, St Paul-Lez-Durance, France
| | - Lu Wang
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China
| | - Yu-Chun Wang
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China
| | - Na-Na Li
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China
| | - Xin-Yuan Hao
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China
| | - Jian-Ming Zeng
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China
| | - Xin-Chao Wang
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China.
| | - Ya-Jun Yang
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310008, People's Republic of China.
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25
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Hou L, Liu L, Zhang H, Zhang L, Zhang L, Zhang J, Gao Q, Wang D. Functional analysis of the mitochondrial alternative oxidase gene (aox1) from Aspergillus niger CGMCC 10142 and its effects on citric acid production. Appl Microbiol Biotechnol 2018; 102:7981-7995. [DOI: 10.1007/s00253-018-9197-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 05/10/2018] [Accepted: 05/14/2018] [Indexed: 11/28/2022]
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26
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Vishwakarma A, Kumari A, Mur LAJ, Gupta KJ. A discrete role for alternative oxidase under hypoxia to increase nitric oxide and drive energy production. Free Radic Biol Med 2018; 122:40-51. [PMID: 29604396 DOI: 10.1016/j.freeradbiomed.2018.03.045] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 03/22/2018] [Accepted: 03/26/2018] [Indexed: 11/27/2022]
Abstract
Alternative oxidase (AOX) is an integral part of the mitochondrial electron transport and can prevent reactive oxygen species (ROS) and nitric oxide (NO) production under non-stressed, normoxic conditions. Here we assessed the roles of AOX by imposing stress under normoxia in comparison to hypoxic conditions using AOX over expressing (AOX OE) and anti-sense (AOX AS) transgenic Arabidopsis seedlings and roots. Under normoxic conditions stress was induced with the defence elicitor flagellin (flg22). AOX OE reduced NO production whilst this was increased in AOX AS. Moreover AOX AS also exhibited an increase in superoxide and therefore peroxynitrite, tyrosine nitration suggesting that scavenging of NO by AOX can prevent toxic peroxynitrite formation under normoxia. In contrast, during hypoxia interestingly we found that AOX is a generator of NO. Thus, the NO produced during hypoxia, was enhanced in AOX OE and suppressed in AOX AS. Additionally, treatment of WT or AOX OE with the AOX inhibitor SHAM inhibited hypoxic NO production. The enhanced levels of NO correlated with expression of non-symbiotic haemoglobin, increased NR activity and ATP production. The ATP generation was suppressed in nia1,2 mutant and non symbiotic haemoglobin antisense line treated with SHAM. Taken together these results suggest that hypoxic NO generation mediated by AOX has a discrete role by feeding into the haemoglobin-NO cycle to drive energy efficiency under conditions of low oxygen tension.
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Affiliation(s)
| | - Aprajita Kumari
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, 110067 New Delhi, India
| | - Luis A J Mur
- Institute of Environmental and Rural Science, Aberystwyth University, Edward Llwyd Building, Aberystwyth SY23 3DA, UK
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27
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Saha B, Borovskii G, Panda SK. Alternative oxidase and plant stress tolerance. PLANT SIGNALING & BEHAVIOR 2016; 11:e1256530. [PMID: 27830987 PMCID: PMC5225930 DOI: 10.1080/15592324.2016.1256530] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Alternative oxidase (AOX) is one of the terminal oxidases of the plant mitochondrial electron transport chain. AOX acts as a means to relax the highly coupled and tensed electron transport process in mitochondria thus providing and maintaining the much needed metabolic homeostasis by directly reducing oxygen to water. In the process AOX also act as facilitator for signaling molecules conveying the metabolic status of mitochondria to the nucleus and thus able to influence nuclear gene expression. Since AOX indirectly, is able to control the synthesis of important signaling molecules like hydrogen peroxide, superoxide, nitric oxide, thus it is also helping in stress signaling. AOX mediated signaling and metabolic activities are very much important for plant stress response. This include both biotic (fungal, bacterial, viral, etc.) and abiotic (drought, salinity, cold, heavy metal, etc.) stresses. The review provides a gist of regulation and functioning of AOX.
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Affiliation(s)
- Bedabrata Saha
- Plant Molecular Biotechnology Laboratory, Department of Life Science & Bioinformatics, Assam University, Silchar, India
| | - Gennadii Borovskii
- Siberian Institute of Plant Physiology & Biochemistry, RAS, Irkutsk, Russia
| | - Sanjib Kumar Panda
- Plant Molecular Biotechnology Laboratory, Department of Life Science & Bioinformatics, Assam University, Silchar, India
- CONTACT Sanjib Kumar Panda
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28
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Boulahia K, Carol P, Planchais S, Abrous-Belbachir O. Phaseolus vulgaris L. Seedlings Exposed to Prometryn Herbicide Contaminated Soil Trigger an Oxidative Stress Response. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:3150-60. [PMID: 27019272 DOI: 10.1021/acs.jafc.6b00328] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Herbicides from the family of S-triazines, such as prometryn, have been widely used in crop production and can constitute an environmental pollution in both water and soil. As a valuable crop, the common bean (Phaseolus vulgaris L.) is grown all over the world and could be exposed to such herbicides. We wanted to investigate the possible stress sustained by the common bean growing in prometryn-polluted soil. Two situations were observed: when soil was treated with ≥100 μM prometryn, some, but not all, measured growth parameters were affected in a dose-dependent manner. Growth was reduced, and photosynthetic pigments and photosynthetic products were less accumulated when soil was treated with ≥100 μM prometryn. Reactive oxygen species (ROS) produced had a deleterious effect, as seen by the accumulation of oxidized lipid in the form of malondialdehyde (MDA). Higher prometryn (500 μM) concentrations had a disastrous effect, reducing antioxidant activities. At a low (10 μM) concentration, prometryn increased antioxidant enzymatic activities without affecting plant growth or MDA production. Gene expression of proline metabolism genes and proline accumulation confirm that bean plants respond to a stress according to the prometryn concentration. Physiological responses such as antioxidative enzymes APX, CAT, and the enzyme implicated in the metabolization of xenobiotics, GST, were increased at 10 and 100 μM, which indicated a prevention of deleterious effects of prometryn, suggesting that bean is a suitable material both for herbicide pollution sensing and as a crop on a low level of herbicide pollution.
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Affiliation(s)
- Kerima Boulahia
- Biology Laboratory and Physiology of Organisms (LBPO), Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene , B.P. 32, El Alia, 16111 Bab Ezzouar, Algiers, Algeria
| | - Pierre Carol
- Institute of Ecology and Environmental Sciences of Paris (iEES), UMR 7618, UPMC CNRS, University Pierre et Marie Curie , Paris, France
| | - Séverine Planchais
- Institute of Ecology and Environmental Sciences of Paris (iEES), UMR 7618, UPMC CNRS, University Pierre et Marie Curie , Paris, France
| | - Ouzna Abrous-Belbachir
- Biology Laboratory and Physiology of Organisms (LBPO), Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene , B.P. 32, El Alia, 16111 Bab Ezzouar, Algiers, Algeria
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Wang F, Wang X, Zhao C, Wang J, Li P, Dou Y, Bi Y. Alternative pathway is involved in the tolerance of highland barley to the low-nitrogen stress by maintaining the cellular redox homeostasis. PLANT CELL REPORTS 2016; 35:317-328. [PMID: 26518429 DOI: 10.1007/s00299-015-1886-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/02/2015] [Accepted: 10/15/2015] [Indexed: 06/05/2023]
Abstract
Alternative pathway (AP) is involved in the tolerance of highland barley seedlings to the low-nitrogen stress by dissipating excessive reducing equivalents generated by photosynthesis and maintaining the cellular redox homeostasis. Low nitrogen (N) is a major limiting factor for plant growth and crop productivity. In this study, we investigated the roles of the alternative pathway (AP) in the tolerance of two barley seedlings, highland barley (Kunlun12) and barley (Ganpi6), to low-N stress. The results showed that the chlorophyll content and the fresh weight decreased more in Ganpi6 than those in Kunlun12 under low-N stress, suggesting that Kunlun12 has higher tolerance to low-N stress than Ganpi6. AP capacity was markedly induced by low-N stress; and it was higher in Kunlun12 than in Ganpi6. Comparatively, the cytochrome pathway capacity was not affected under all conditions. Western-blot analysis showed that the protein level of the alternative oxidase (AOX) increased under low-N stress in Kunlun12 but not in Ganpi6. Under low-N stress, the NAD(P)H content and the NAD(P)H to NAD(P)(+)+NAD(P)H ratio in Ganpi6 increased more than those in Kunlun12. Furthermore, photosynthetic parameters (Fv/Fm, qP, ETR and Yield) decreased markedly and qN increased, indicating photoinhibition occurred in both barley seedlings, especially in Ganpi6. When AP was inhibited by salicylhydroxamic acid (SHAM), the NAD(P)H content and the NAD(P)H to NAD(P)(+)+NAD(P)H ratio dramatically increased under all conditions, resulting in the marked accumulation of H(2)O(2) and malondialdehyde in leaves of both barley seedlings. Meanwhile, the malate-oxaloacetate shuttle activity and the photosynthetic efficiency were further inhibited. Taken together, AP is involved in the tolerance of highland barley seedlings to low-N stress by dissipating excess reducing equivalents and maintaining the cellular redox homeostasis.
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Affiliation(s)
- Feng Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, People's Republic of China
| | - Xiaomin Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, People's Republic of China
| | - Chengzhou Zhao
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, People's Republic of China
| | - Jianfeng Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, People's Republic of China
| | - Ping Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, People's Republic of China
| | - Yanqin Dou
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, People's Republic of China
| | - Yurong Bi
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, People's Republic of China.
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Vishwakarma A, Dalal A, Tetali SD, Kirti PB, Padmasree K. Genetic engineering of AtAOX1a in Saccharomyces cerevisiae prevents oxidative damage and maintains redox homeostasis. FEBS Open Bio 2016; 6:135-46. [PMID: 27239435 PMCID: PMC4821348 DOI: 10.1002/2211-5463.12028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 12/31/2015] [Accepted: 12/31/2015] [Indexed: 02/02/2023] Open
Abstract
This study aimed to validate the physiological importance of Arabidopsis thaliana alternative oxidase 1a (AtAOX1a) in alleviating oxidative stress using Saccharomyces cerevisiae as a model organism. The AOX1a transformant (pYES2AtAOX1a) showed cyanide resistant and salicylhydroxamic acid (SHAM)‐sensitive respiration, indicating functional expression of AtAOX1a in S. cerevisiae. After exposure to oxidative stress, pYES2AtAOX1a showed better survival and a decrease in reactive oxygen species (ROS) when compared to S. cerevisiae with empty vector (pYES2). Furthermore, pYES2AtAOX1a sustained growth by regulating GPX2 and/or TSA2, and cellular NAD+/NADH ratio. Thus, the expression of AtAOX1a in S. cerevisiae enhances its respiratory tolerance which, in turn, maintains cellular redox homeostasis and protects from oxidative damage.
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Affiliation(s)
- Abhaypratap Vishwakarma
- Department of Plant Sciences School of Life Sciences University of Hyderabad Hyderabad India
| | - Ahan Dalal
- Department of Plant Sciences School of Life Sciences University of Hyderabad Hyderabad India
| | - Sarada Devi Tetali
- Department of Plant Sciences School of Life Sciences University of Hyderabad Hyderabad India
| | | | - Kollipara Padmasree
- Department of Biotechnology and Bioinformatics School of Life Sciences University of Hyderabad Hyderabad India
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Hedayati V, Mousavi A, Razavi K, Cultrera N, Alagna F, Mariotti R, Hosseini-Mazinani M, Baldoni L. Polymorphisms in the AOX2 gene are associated with the rooting ability of olive cuttings. PLANT CELL REPORTS 2015; 34:1151-64. [PMID: 25749737 DOI: 10.1007/s00299-015-1774-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 02/11/2015] [Accepted: 02/17/2015] [Indexed: 05/05/2023]
Abstract
Different rooting ability candidate genes were tested on an olive cross progeny. Our results demonstrated that only the AOX2 gene was strongly induced. OeAOX2 was fully characterised and correlated to phenotypical traits. The formation of adventitious roots is a key step in the vegetative propagation of trees crop species, and this ability is under strict genetic control. While numerous studies have been carried out to identify genes controlling adventitious root formation, only a few loci have been characterised. In this work, candidate genes that were putatively involved in rooting ability were identified in olive (Olea europaea L.) by similarity with orthologs identified in other plant species. The mRNA levels of these genes were analysed by real-time PCR during root induction in high- (HR) and low-rooting (LR) individuals. Interestingly, alternative oxidase 2 (AOX2), which was previously reported to be a functional marker for rooting in olive cuttings, showed a strong induction in HR individuals. From the OeAOX2 full-length gene, alleles and effective polymorphisms were distinguished and analysed in the cross progeny, which were segregated based on rooting. The results revealed a possible correlation between two single nucleotide polymorphisms of OeAOX2 gene and rooting ability.
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Affiliation(s)
- Vahideh Hedayati
- National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
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32
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Keunen E, Schellingen K, Van Der Straeten D, Remans T, Colpaert J, Vangronsveld J, Cuypers A. ALTERNATIVE OXIDASE1a modulates the oxidative challenge during moderate Cd exposure in Arabidopsis thaliana leaves. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2967-2977. [PMID: 25743159 DOI: 10.1093/jxb/erv035] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This study aims to unravel the functional significance of alternative oxidase1a (AOX1a) induction in Arabidopsis thaliana leaves exposed to cadmium (Cd) by comparing wild-type (WT) plants and aox1a knockout mutants. In the absence of AOX1a, differences in stress-responsive transcript and glutathione levels suggest an increased oxidative challenge during moderate (5 µM) and prolonged (72h) Cd exposure. Nevertheless, aox1a knockout leaves showed lower hydrogen peroxide (H2O2) accumulation as compared to the WT due to both acute (24h) and prolonged (72h) exposure to 5 µM Cd, but not to 10 µM Cd. Taken together, we propose a working model where AOX1a acts early in the response to Cd and activates or maintains a mitochondrial signalling pathway impacting on cellular antioxidative defence at the post-transcriptional level. This fine-tuning pathway is suggested to function during moderate (5 µM) Cd exposure while being overwhelmed during more severe (10 µM) Cd stress. Within this framework, ethylene is required - either directly or indirectly via NADPH oxidase isoform C - to fully induce AOX1 expression. In addition, reciprocal crosstalk between these components was demonstrated in leaves of A. thaliana plants exposed to Cd.
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Affiliation(s)
- Els Keunen
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek, Belgium
| | - Kerim Schellingen
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek, Belgium
| | - Dominique Van Der Straeten
- Laboratory of Functional Plant Biology, Ghent University, Karel Lodewijk Ledeganckstraat 35, B-9000 Ghent, Belgium
| | - Tony Remans
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek, Belgium
| | - Jan Colpaert
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek, Belgium
| | - Jaco Vangronsveld
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek, Belgium
| | - Ann Cuypers
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek, Belgium
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Erdal S, Genisel M, Turk H, Dumlupinar R, Demir Y. Modulation of alternative oxidase to enhance tolerance against cold stress of chickpea by chemical treatments. JOURNAL OF PLANT PHYSIOLOGY 2015; 175:95-101. [PMID: 25543861 DOI: 10.1016/j.jplph.2014.10.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/17/2014] [Accepted: 10/10/2014] [Indexed: 05/04/2023]
Abstract
The alternative oxidase (AOX) is the enzyme responsible for the alternative respiratory pathway. This experiment was conducted to examine the influence on cold tolerance ability of chickpea (Cicer aurentium cv. Müfitbey) seedlings of AOX activator (pyruvate), AOX inhibitor (salicylhydroxamic acid (SHAM)) and an inhibitor of the cytochrome pathway of respiration (antimycin A) treatments. 5mM pyruvate, 2μM antimycin A and 4mM SHAM solutions were exogenously applied to thirteen-day-old chickpea leaves and then the seedlings were transferred to a different plant growth chamber arranged to 10/5°C (day/night) for 48h. Cold stress markedly increased the activities of antioxidant enzymes compared to controls. Pyruvate and antimycin A significantly increased the cold-induced increase in antioxidant activity but SHAM decreased it. Cold-induced increases in superoxide anion, hydrogen peroxide, and lipid peroxidation levels were significantly reduced by pyruvate and antimycin A, but increased by SHAM treatment. Pyruvate and antimycin A application increased both the activity and protein expression of AOX in comparison to cold stress alone. However, SHAM significantly decreased activity of AOX but did not affect its expression. Total cellular respiration values (TCRV) supported the changes in activity and expression of AOX. While TCRV were increased by cold and pyruvate, they were significantly reduced by SHAM and especially antimycin A. These results indicate that pyruvate and antimycin A applications were effective in reducing oxidative stress by activating the alternative respiratory pathway as well as antioxidant activity. Furthermore, direct activation of AOX, rather than inhibition of the cytochrome pathway, was the most effective way to mitigate cold stress.
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Affiliation(s)
- Serkan Erdal
- Department of Biology, Science Faculty, Ataturk University, Erzurum, Turkey.
| | - Mucip Genisel
- Organic Agriculture Program, Vocational High School, Agri Ibrahim Cecen University, 04100 Agri, Turkey
| | - Hulya Turk
- Department of Biology, Science Faculty, Ataturk University, Erzurum, Turkey
| | - Rahmi Dumlupinar
- Department of Biology, Science Faculty, Ataturk University, Erzurum, Turkey
| | - Yavuz Demir
- Department of Biology, K. K. Education Faculty, Ataturk University, Erzurum, Turkey
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Li L, Hu L, Han LP, Ji H, Zhu Y, Wang X, Ge J, Xu M, Shen D, Dong H. Expression of turtle riboflavin-binding protein represses mitochondrial electron transport gene expression and promotes flowering in Arabidopsis. BMC PLANT BIOLOGY 2014; 14:381. [PMID: 25547226 PMCID: PMC4310184 DOI: 10.1186/s12870-014-0381-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 12/11/2014] [Indexed: 05/12/2023]
Abstract
BACKGROUND Recently we showed that de novo expression of a turtle riboflavin-binding protein (RfBP) in transgenic Arabidopsis increased H2O2 concentrations inside leaf cells, enhanced the expression of floral regulatory gene FD and floral meristem identity gene AP1 at the shoot apex, and induced early flowering. Here we report that RfBP-induced H2O2 presumably results from electron leakage at the mitochondrial electron transport chain (METC) and this source of H2O2 contributes to the early flowering phenotype. RESULTS While enhanced expression of FD and AP1 at the shoot apex was correlated with early flowering, the foliar expression of 13 of 19 METC genes was repressed in RfBP-expressing (RfBP+) plants. Inside RfBP+ leaf cells, cytosolic H2O2 concentrations were increased possibly through electron leakage because similar responses were also induced by a known inducer of electron leakage from METC. Early flowering no longer occurred when the repression on METC genes was eliminated by RfBP gene silencing, which restored RfBP+ to wild type in levels of FD and AP1 expression, H2O2, and flavins. Flowering was delayed by the external riboflavin application, which brought gene expression and flavins back to the steady-state levels but only caused 55% reduction of H2O2 concentrations in RfBP+ plants. RfBP-repressed METC gene expression remedied the cytosolic H2O2 diminution by genetic disruption of transcription factor NFXLl and compensated for compromises in FD and AP1 expression and flowering time. By contrast, RfBP resembled a peroxisomal catalase mutation, which augments the cytosolic H2O2, to enhance FD and AP1 expression and induce early flowering. CONCLUSIONS RfBP-repressed METC gene expression potentially causes electron leakage as one of cellular sources for the generation of H2O2 with the promoting effect on flowering. The repressive effect on METC gene expression is not the only way by which RfBP induces H2O2 and currently unappreciated factors may also function under RfBP+ background.
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Affiliation(s)
- Liang Li
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Li Hu
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Li-Ping Han
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Hongtao Ji
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Yueyue Zhu
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Xiaobing Wang
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Jun Ge
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Manyu Xu
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Dan Shen
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Hansong Dong
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
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Liu J, Li Z, Wang Y, Xing D. Overexpression of ALTERNATIVE OXIDASE1a alleviates mitochondria-dependent programmed cell death induced by aluminium phytotoxicity in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:4465-78. [PMID: 24863436 DOI: 10.1093/jxb/eru222] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Alternative oxidase (AOX) is a terminal oxidase found in all plants, and functions to maintain the electron flux and reduce the production of reactive oxygen species (ROS). Our previous study demonstrated that aluminium (Al) treatment could induce increased expression of the AOX1a gene, but the mechanism of how AOX1a participates in the regulation of Al-induced programmed cell death (PCD) is still not clear. To investigate the possible mechanism, mitochondrial ROS production and the behaviour of mitochondria, as well as caspase-3-like activation were monitored under Al treatment in wild-type (WT), AOX1a-lacking (aox1a), and AOX1a-overexpressing (AOX1a-OE) Arabidopsis. Our results showed that Al treatment increased the expression of AOX1a at both the transcriptional and translational levels. Overexpression of AOX1a reduced mitochondrial ROS production by maintaining the mitochondrial electron flux, and alleviated subsequent mitochondrial dysfunction and caspase-3-like activation in Al-induced PCD. Moreover, it was found that a change in AOX1a level could influence the expression levels of downstream functional genes that play protective roles in Al-induced PCD. Experiments using mutants and inhibitors demonstrated that superoxide anion (O2 (-)) derived from mitochondria was involved in Al-induced upregulation of AOX1a gene expression. Taken together, these results indicated that overexpression of AOX1a alleviated Al-induced PCD by maintaining mitochondrial function and promoting the expression of protective functional genes, providing new insights into the signalling cascades that modulate the Al phytotoxicity mechanism.
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Affiliation(s)
- Jian Liu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, PR China
| | - Zhe Li
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, PR China
| | - Yongqiang Wang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, PR China
| | - Da Xing
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, PR China
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Vishwakarma A, Bashyam L, Senthilkumaran B, Scheibe R, Padmasree K. Physiological role of AOX1a in photosynthesis and maintenance of cellular redox homeostasis under high light in Arabidopsis thaliana. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 81:44-53. [PMID: 24560882 DOI: 10.1016/j.plaphy.2014.01.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 01/27/2014] [Indexed: 05/27/2023]
Abstract
As plants are sessile, they often face high light (HL) stress that causes damage of the photosynthetic machinery leading to decreased photosynthesis. The importance of alternative oxidase (AOX) in optimizing photosynthesis is well documented. In the present study, the role of AOX in sustaining photosynthesis under HL was studied using AOX1a knockout mutants (aox1a) of Arabidopsis thaliana. Under growth light (GL; 50 μmol photons m(-2) s(-1)) conditions, aox1a plants did not show any changes in photosynthetic parameters, NAD(P)/H redox ratios, or respiratory O2 uptake when compared to wild-type (WT). Upon exposure to HL (700 μmol photons m(-2) s(-1)), respiratory rates did not vary between WT and aox1a. But, photosynthetic parameters related to photosystem II (PSII) and NaHCO3 dependent O2 evolution decreased, while the P700 reduction state increased in aox1a compared to WT. Further, under HL, the redox state of cellular NAD(P)/H pools increased with concomitant rise in reactive oxygen species (ROS) and malondialdehyde (MDA) content in aox1a compared to WT. In presence of HL, the transcript levels of several genes related to antioxidant, malate-oxaloacetate (malate-OAA) shuttle, photorespiratory and respiratory enzymes was higher in aox1a compared to WT. Taken together, these results demonstrate that under HL, in spite of significant increase in transcript levels of several genes mentioned above to maintain cellular redox homeostasis and minimize ROS production, Arabidopsis plants deficient in AOX1a were unable to sustain photosynthesis as is the case in WT plants.
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Affiliation(s)
- Abhaypratap Vishwakarma
- Department of Plant Sciences, School of Life Sciences, Centre for Advanced Studies, University of Hyderabad, Hyderabad 500 046, India
| | - Leena Bashyam
- Genomics Facility, University of Hyderabad, Hyderabad 500 046, India
| | - Balasubramanian Senthilkumaran
- Department of Animal Sciences, School of Life Sciences, Centre for Advanced Studies, University of Hyderabad, Hyderabad 500 046, India
| | - Renate Scheibe
- Department of Plant Physiology, FB5, University of Osnabrueck, 49069 Osnabrueck, Germany
| | - Kollipara Padmasree
- Department of Plant Sciences, School of Life Sciences, Centre for Advanced Studies, University of Hyderabad, Hyderabad 500 046, India; Department of Plant Physiology, FB5, University of Osnabrueck, 49069 Osnabrueck, Germany; Department of Biotechnology and Bioinformatics, School of Life Sciences, Centre for Advanced Studies, University of Hyderabad, Hyderabad 500 046, India.
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Cvetkovska M, Dahal K, Alber NA, Jin C, Cheung M, Vanlerberghe GC. Knockdown of mitochondrial alternative oxidase induces the 'stress state' of signaling molecule pools in Nicotiana tabacum, with implications for stomatal function. THE NEW PHYTOLOGIST 2014; 203:449-461. [PMID: 24635054 DOI: 10.1111/nph.12773] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 02/19/2014] [Indexed: 05/18/2023]
Abstract
The mitochondrial electron transport chain (ETC) includes an alternative oxidase (AOX) that may control the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). ROS and RNS act as signaling intermediates in numerous plant processes, including stomatal movement. The role of AOX in controlling ROS and RNS concentrations under both steady-state and different stress conditions was evaluated using Nicotiana tabacum plants lacking AOX as a result of RNA interference. A potential functional implication of changes in ROS and RNS homeostasis was also evaluated by examining stomatal function. The leaves of nonstressed AOX knockdowns maintained concentrations of H2O2 and nitric oxide (NO) normally seen in wildtype plants only under stress conditions. Further, guard cell NO amounts were much higher in knockdowns. These guard cells were altered in size and were less responsive to NO as a signal for stomatal closure. This, in turn, compromised the stomatal response to changing irradiance. The results reveal a role for AOX in stomata. A working model is that guard cell AOX respiration maintains NO homeostasis by preventing over-reduction of the ETC, particularly during periods when high concentrations of NO acting as a signal for stomatal closure may also be inhibiting cyt oxidase respiration.
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Affiliation(s)
- Marina Cvetkovska
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Keshav Dahal
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Nicole A Alber
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Cathy Jin
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Melissa Cheung
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Greg C Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
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Affiliation(s)
- Kapuganti J Gupta
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Luis A J Mur
- Institute of Environmental and Rural Science, Aberystwyth University, Edward Llwyd Building, Aberystwyth, SY23 3DA, UK
| | - R George Ratcliffe
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
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39
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40
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Wang J, Vanlerberghe GC. A lack of mitochondrial alternative oxidase compromises capacity to recover from severe drought stress. PHYSIOLOGIA PLANTARUM 2013; 149:461-73. [PMID: 23582049 DOI: 10.1111/ppl.12059] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 03/25/2013] [Accepted: 04/07/2013] [Indexed: 05/19/2023]
Abstract
Alternative oxidase (AOX) constitutes a nonenergy conserving branch of the mitochondrial electron transport chain. AOX activity may be important to avoid reactive oxygen species (ROS) generation by the chain, particularly during abiotic stress. We compared leaf AOX1a transcript and AOX protein amounts in wild-type (WT) Nicotiana tabacum plants experiencing mild to severe drought. Mild to moderate drought resulted in a progressive and modest increase in AOX amount, accompanied by a progressive increased expression of different ROS-scavenging components. Under these conditions, transgenic plants with suppressed AOX amount, due to an RNA interference construct, were not compromised in their ability to manage ROS load and prevent cellular damage. Severe drought stress, particularly when combined with increased irradiance, strongly increased AOX amount in WT tobacco and this coincided with an increase in total respiration and, despite further induction of ROS-scavenging systems, some evidence of cellular damage. Under these severe conditions, plants lacking AOX suffered more cellular damage than WT and, at the most severe stage, were found to downregulate rather than upregulate the transcript level of several important ROS-scavenging components. At this stage, WT plants could still recover rapidly after rewatering, but the recoverability of AOX knockdown plants was strongly compromised.
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Affiliation(s)
- Jia Wang
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada, M1C 1A4
| | - Greg C Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada, M1C 1A4
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41
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Keunen E, Peshev D, Vangronsveld J, Van Den Ende W, Cuypers A. Plant sugars are crucial players in the oxidative challenge during abiotic stress: extending the traditional concept. PLANT, CELL & ENVIRONMENT 2013; 36:1242-55. [PMID: 23305614 DOI: 10.1111/pce.12061] [Citation(s) in RCA: 355] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 12/20/2012] [Accepted: 12/26/2012] [Indexed: 05/18/2023]
Abstract
Plants suffering from abiotic stress are commonly facing an enhanced accumulation of reactive oxygen species (ROS) with damaging as well as signalling effects at organellar and cellular levels. The outcome of an environmental challenge highly depends on the delicate balance between ROS production and scavenging by both enzymatic and metabolic antioxidants. However, this traditional classification is in need of renewal and reform, as it is becoming increasingly clear that soluble sugars such as disaccharides, raffinose family oligosaccharides and fructans--next to their associated metabolic enzymes--are strongly related to stress-induced ROS accumulation in plants. Therefore, this review aims at extending the current concept of antioxidants functioning during abiotic stress, with special focus on the emanate role of sugars as true ROS scavengers. Examples are given based on their cellular location, as different organelles seem to exploit distinct mechanisms. Moreover, the vacuole comes into the picture as important player in the ROS signalling network of plants. Elucidating the interplay between the mechanisms controlling ROS signalling during abiotic stress will facilitate the development of strategies to enhance crop tolerance to stressful environmental conditions.
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Affiliation(s)
- Els Keunen
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590, Diepenbeek, Belgium
| | - Darin Peshev
- Laboratory of Molecular Plant Biology and Leuven Food Science and Nutrition Research Centre (LFoRCe), KULeuven, Kasteelpark Arenberg 31, B-3001, Leuven, Belgium
| | - Jaco Vangronsveld
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590, Diepenbeek, Belgium
| | - Wim Van Den Ende
- Laboratory of Molecular Plant Biology and Leuven Food Science and Nutrition Research Centre (LFoRCe), KULeuven, Kasteelpark Arenberg 31, B-3001, Leuven, Belgium
| | - Ann Cuypers
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, B-3590, Diepenbeek, Belgium
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Panda SK, Sahoo L, Katsuhara M, Matsumoto H. Overexpression of alternative oxidase gene confers aluminum tolerance by altering the respiratory capacity and the response to oxidative stress in tobacco cells. Mol Biotechnol 2013; 54:551-63. [PMID: 22965419 DOI: 10.1007/s12033-012-9595-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aluminum (Al) stress represses mitochondrial respiration and produces reactive oxygen species (ROS) in plants. Mitochondrial alternative oxidase (AOX) uncouples respiration from mitochondrial ATP production and may improve plant performance under Al stress by preventing excess accumulation of ROS. We tested respiratory changes and ROS production in isolated mitochondria and whole cell of tobacco (SL, ALT 301) under Al stress. Higher capacities of AOX pathways relative to cytochrome pathways were observed in both isolated mitochondria and whole cells of ALT301 under Al stress. AOX1 when studied showed higher AOX1 expression in ALT 301 than SL cells under stress. In order to study the function of tobacco AOX gene under Al stress, we produced transformed tobacco cell lines by introducing NtAOX1 expressed under the control of the cauliflower mosaic virus (CaMV) 35 S promoter in sensitive (SL) Nicotiana tabacum L. cell lines. The enhancement of endogenous AOX1 expression and AOX protein with or without Al stress was in the order of transformed tobacco cell lines > ALT301 > wild type (SL). A decreased respiratory inhibition and reduced ROS production with a better growth capability were the significant features that characterized AOX1 transformed cell lines under Al stress. These results demonstrated that AOX plays a critical role in Al stress tolerance with an enhanced respiratory capacity, reducing mitochondrial oxidative stress burden and improving the growth capability in tobacco cells.
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Affiliation(s)
- Sanjib Kumar Panda
- Department of Life Science & Bioinformatics, Assam University, Silchar, India.
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Vanlerberghe GC. Alternative oxidase: a mitochondrial respiratory pathway to maintain metabolic and signaling homeostasis during abiotic and biotic stress in plants. Int J Mol Sci 2013; 14:6805-47. [PMID: 23531539 PMCID: PMC3645666 DOI: 10.3390/ijms14046805] [Citation(s) in RCA: 405] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 03/08/2013] [Accepted: 03/12/2013] [Indexed: 02/07/2023] Open
Abstract
Alternative oxidase (AOX) is a non-energy conserving terminal oxidase in the plant mitochondrial electron transport chain. While respiratory carbon oxidation pathways, electron transport, and ATP turnover are tightly coupled processes, AOX provides a means to relax this coupling, thus providing a degree of metabolic homeostasis to carbon and energy metabolism. Beside their role in primary metabolism, plant mitochondria also act as "signaling organelles", able to influence processes such as nuclear gene expression. AOX activity can control the level of potential mitochondrial signaling molecules such as superoxide, nitric oxide and important redox couples. In this way, AOX also provides a degree of signaling homeostasis to the organelle. Evidence suggests that AOX function in metabolic and signaling homeostasis is particularly important during stress. These include abiotic stresses such as low temperature, drought, and nutrient deficiency, as well as biotic stresses such as bacterial infection. This review provides an introduction to the genetic and biochemical control of AOX respiration, as well as providing generalized examples of how AOX activity can provide metabolic and signaling homeostasis. This review also examines abiotic and biotic stresses in which AOX respiration has been critically evaluated, and considers the overall role of AOX in growth and stress tolerance.
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Affiliation(s)
- Greg C Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C1A4, Canada.
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44
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Cvetkovska M, Vanlerberghe GC. Alternative oxidase impacts the plant response to biotic stress by influencing the mitochondrial generation of reactive oxygen species. PLANT, CELL & ENVIRONMENT 2013; 36:721-32. [PMID: 22978428 DOI: 10.1111/pce.12009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Previously, we showed that inoculation of tobacco with Pseudomonas syringae incompatible pv. maculicola results in a rapid and persistent burst of superoxide (O(2) (-) ) from mitochondria, no change in amount of mitochondrial alternative oxidase (AOX) and induction of the hypersensitive response (HR). However, inoculation with incompatible pv. phaseolicola resulted in increased AOX, no O(2) (-) burst and no HR. Here, we show that in transgenic plants unable to induce AOX in response to pv. phaseolicola, there is now a strong mitochondrial O(2) (-) burst, similar to that normally seen only with pv. maculicola. This interaction did not however result in a HR. This indicates that AOX amount is a key determinant of the mitochondrial O(2) (-) burst but also that the burst itself is not sufficient to induce the HR. Surprisingly, the O(2) (-) burst normally seen towards pv. maculicola is delayed in plants lacking AOX. This delay is associated with a delayed HR, suggesting that the burst does promote the HR. A O(2) (-) burst can also be induced by the complex III inhibitor antimycin A (AA), but is again delayed in plants lacking AOX. The similar mitochondrial response induced by pv. maculicola and AA suggests that electron transport is a target during HR-inducing biotic interactions.
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Affiliation(s)
- Marina Cvetkovska
- Departments of Biological Sciences and Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
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Abstract
The recognition of phytophagous insects by plants induces a set of very specific responses aimed at deterring tissue consumption and reprogramming metabolism and development of the plant to tolerate the herbivore. The recognition of insects by plants requires the plant's ability to perceive chemical cues generated by the insects and to distinguish a particular pattern of tissue disruption. Relatively little is known about the molecular basis of insect perception by plants and the signalling mechanisms directly associated with this perception. Importantly, the insect feeding behaviour (piercing-sucking versus chewing) is a decisive determinant of the plant's defence response, and the mechanisms used to perceive insects from different feeding guilds may be distinct. During insect feeding, components of the saliva of chewing or piercing-sucking insects come into contact with plant cells, and elicitors or effectors present in this insect-derived fluid are perceived by plant cells to initiate the activation of specific signalling cascades. Although receptor-ligand interactions controlling insect perception have yet not been molecularly described, a significant number of regulatory components acting downstream of receptors and involved in the activation of defence responses against insects has been reported. Some of these regulators mediate changes in the phytohormone network, while others directly control gene expression or the redox state of the cell. These processes are central in the orchestration of plant defence responses against insects.
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Affiliation(s)
- G Bonaventure
- Department of Molecular Ecology, Max Planck Institute of Chemical Ecology, Jena, Germany.
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Comparison of intact Arabidopsis thaliana leaf transcript profiles during treatment with inhibitors of mitochondrial electron transport and TCA cycle. PLoS One 2012; 7:e44339. [PMID: 23028523 PMCID: PMC3445595 DOI: 10.1371/journal.pone.0044339] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 08/02/2012] [Indexed: 01/02/2023] Open
Abstract
Plant mitochondria signal to the nucleus leading to altered transcription of nuclear genes by a process called mitochondrial retrograde regulation (MRR). MRR is implicated in metabolic homeostasis and responses to stress conditions. Mitochondrial reactive oxygen species (mtROS) are a MRR signaling component, but whether all MRR requires ROS is not established. Inhibition of the cytochrome respiratory pathway by antimycin A (AA) or the TCA cycle by monofluoroacetate (MFA), each of which initiates MRR, can increase ROS production in some plant cells. We found that for AA and MFA applied to leaves of soil-grown Arabidopsis thaliana plants, ROS production increased with AA, but not with MFA, allowing comparison of transcript profiles under different ROS conditions during MRR. Variation in transcript accumulation over time for eight nuclear encoded mitochondrial protein genes suggested operation of both common and distinct signaling pathways between the two treatments. Consequences of mitochondrial perturbations for the whole transcriptome were examined by microarray analyses. Expression of 1316 and 606 genes was altered by AA and MFA, respectively. A subset of genes was similarly affected by both treatments, including genes encoding photosynthesis-related proteins. MFA treatment resulted in more down-regulation. Functional gene category (MapMan) and cluster analyses showed that genes with expression levels affected by perturbation from AA or MFA inhibition were most similarly affected by biotic stresses such as pathogens. Overall, the data provide further evidence for the presence of mtROS-independent MRR signaling, and support the proposed involvement of MRR and mitochondrial function in plant responses to biotic stress.
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Santos Macedo E, Sircar D, Cardoso HG, Peixe A, Arnholdt-Schmitt B. Involvement of alternative oxidase (AOX) in adventitious rooting of Olea europaea L. microshoots is linked to adaptive phenylpropanoid and lignin metabolism. PLANT CELL REPORTS 2012; 31:1581-90. [PMID: 22544084 DOI: 10.1007/s00299-012-1272-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 04/15/2012] [Indexed: 05/05/2023]
Abstract
UNLABELLED Alternative oxidase (AOX) has been proposed as a functional marker candidate in a number of events involving cell differentiation, including rooting efficiency in semi-hardwood shoot cuttings of olive (Olea europaea L.). To ascertain the general importance of AOX in olive rooting, the auxin-induced rooting process was studied in an in vitro system for microshoot propagation. Inhibition of AOX by salicylhydroxamic acid (SHAM) significantly reduced rooting efficiency. However, the inhibitor failed to exhibit any effect on the preceding calli stage. This makes the system appropriate for distinguishing dedifferentiation and de novo differentiation during root induction. Metabolite analyses of microshoots showed that total phenolics, total flavonoids and lignin contents were significantly reduced upon SHAM treatment. It was concluded that the influence of alternative respiration on root formation was associated to adaptive phenylpropanoid and lignin metabolism. Transcript profiles of two olive AOX genes (OeAOX1a and OeAOX2) were examined during the process of auxin-induced root induction. Both genes displayed stable transcript accumulation in semi-quantitative RT-PCR analysis during all experimental stages. In contrary, when the reverse primer for OeAOX2 was designed from the 3'-UTR instead of the ORF, differential transcript accumulation was observed suggesting posttranscriptional regulation of OeAOX2 during metabolic acclimation. This result confirms former observations in olive semi-hardwood shoot cuttings on differential OeAOX2 expression during root induction. It further points to the importance of future studies on the functional role of sequence and length polymorphisms in the 3'-UTR of this gene. KEY MESSAGE The manuscript reports the general importance of AOX in olive adventitious rooting and the association of alternative respiration to adaptive phenylpropanoid and lignin metabolism.
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Affiliation(s)
- E Santos Macedo
- Laboratory of Molecular Biology, ICAAM, University of Évora, 7002-554, Évora, Portugal
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Cvetkovska M, Vanlerberghe GC. Alternative oxidase modulates leaf mitochondrial concentrations of superoxide and nitric oxide. THE NEW PHYTOLOGIST 2012; 195:32-9. [PMID: 22537177 DOI: 10.1111/j.1469-8137.2012.04166.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
• The nonenergy-conserving alternative oxidase (AOX) has been hypothesized to modulate the amount of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in plant mitochondria but there is sparse direct in planta evidence to support this. • Laser scanning fluorescent confocal microscopy and biochemical methods were used to directly estimate in planta leaf concentrations of superoxide (O2(-)), nitric oxide (NO), peroxynitrite (ONOO(-)) and hydrogen peroxide (H(2)O(2)) in wildtype (Wt) tobacco (Nicotiana tabacum) and transgenic tobacco with altered amounts of AOX. • We found that plants lacking AOX have increased concentrations of leaf mitochondrial-localized O2(-) and leaf NO in comparison to the Wt, while leaf concentrations of H(2)O(2) were similar or lower in the AOX-suppressed plants. • Based on our results, we suggest that AOX respiration acts to reduce the generation of ROS and RNS in plant mitochondria by dampening the leak of single electrons from the electron transport chain to O(2) or nitrite. This may represent a universal role for AOX in plants. More work is now needed to establish the functional implications of this role, such as during abiotic and biotic stress.
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Affiliation(s)
- Marina Cvetkovska
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
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Chai TT, Simmonds D, Day DA, Colmer TD, Finnegan PM. A GmAOX2b antisense gene compromises vegetative growth and seed production in soybean. PLANTA 2012; 236:199-207. [PMID: 22307678 DOI: 10.1007/s00425-012-1601-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 01/20/2012] [Indexed: 05/21/2023]
Abstract
The alternative oxidase mediates the cyanide-resistant respiratory pathway in plant mitochondria. In non-thermogenic plants, the role of alternative oxidase in plant growth and development is not well understood. Soybean (Glycine max) lines carrying a GmAOX2b antisense gene had compromised vegetative growth and reproductive performance under typical glasshouse growth conditions. The reduction in vegetative growth was demonstrated by reduction in shoot height, the number of leaves per plant and the green leaf area. Antisense plants also had decreased pod formation and seed to pod ratios, which together led to a reduction in the number and total mass of seed produced. The negative effects of the antisense gene on pod set, seed set, ovule availability and total seed mass were primarily confined to the branches, rather than the main stem. The preferential effect of alternative oxidase suppression in the branches is discussed in relation to the reproductive potential of soybean under stress. Taken together, these results demonstrate that alternative oxidase provides the benefit of sustaining plant vegetative growth and reproductive capacity in soybean.
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Affiliation(s)
- Tsun-Thai Chai
- Faculty of Natural and Agricultural Sciences, School of Plant Biology and Institute of Agriculture, The University of Western Australia, Crawley, WA 6009, Australia
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Zhang BY, He LW, Jia ZJ, Wang GC, Peng G. CHARACTERIZATION OF THE ALTERNATIVE OXIDASE GENE IN PORPHYRA YEZOENSIS (RHODOPHYTA) AND CYANIDE-RESISTANT RESPIRATION ANALYSIS(1). JOURNAL OF PHYCOLOGY 2012; 48:657-663. [PMID: 27011081 DOI: 10.1111/j.1529-8817.2012.01129.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The full-length cDNA of the alternative oxidase (AOX) gene from Porphyra yezoensis Ueda (PyAOX) [currently assigned as Pyropia yezoensis (Ueda) M. S. Hwang et H. G. Choi (http://www.algaebase.org)] an ancient member of the Rhodphyta, was cloned by electronic cloning, rapid amplification of cDNA ends (RACE), and reverse transcription PCR. The nucleotide sequence of PyAOX consists of 1,650 bp, including a 5' untranslated region (UTR) of 170 bp, a 3' UTR of 148 bp, and an open reading frame (ORF) of 1,332 bp that can be translated into a 443-amino-acid residue with a molecular mass of 47.33 kDa and a putative isoelectric point (pI) of 9.71. The putative amino acids had 50%-61% identity with AOX genes in Eukaryota and higher plants and had AOX-like characteristics. The expression of PyAOX mRNA in different stages of the life cycle, conchospores, filamentous thalli (conchocelis stage), and leafy thalli, was detected by real-time quantitative PCR (qPCR). The highest level of expression, which was observed in filamentous thalli, was three times higher than that observed in leafy thalli. The next highest level, which was observed in the conchospores, was twice as high as that observed in leafy thalli. We showed that an alternative respiration pathway existed in P. yezoensis with a noninvasive microsensing system. The contribution of the alternative pathway to total respiration in filamentous thalli was greater than that in leafy thalli. This result was consistent with the level of AOX gene expression observed in different stages of the life cycle.
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Affiliation(s)
- Bao Y Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin, 300457, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Lin W He
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin, 300457, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Zhao J Jia
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin, 300457, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Guang C Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin, 300457, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Guang Peng
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin, 300457, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
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