Expression and signal regulation of the alternative oxidase genes under abiotic stresses

Hong, Feng; Guan, Dongdong; Sun, Kun; Wang, Yifeng; Zhang, Tengguo; Wang, Rongfang

doi:10.1093/abbs/gmt094

Cited by 40 publications

(24 citation statements)

References 98 publications

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“…AOX was shown to be involved in the defense against drought in N. tabacum leaves due to its ability to reduce oxidative damage (Dahal & Vanlerberghe, ). Conditions reported to modulate AOX expression or activity include chilling, drought, light stress, high salt, nutrient limitation, ozone, metal toxicity and heat stress (see Feng et al ., ; Del‐Saz et al ., , and references therein). Several signaling molecules have been reported to regulate AOX under stress, including calcium, nitric oxide (NO), abscisic acid, salicylic acid, ethylene, H 2 O 2 , superoxide, cyanide and citrate (Feng et al ., ; Vanlerberghe, ).…”

Section: Introductionmentioning

confidence: 99%

Downregulation of mitochondrial alternative oxidase affects chloroplast function, redox status and stress response in a marine diatom

et al. 2018

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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 H O , 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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Section: Introductionmentioning

confidence: 99%

Downregulation of mitochondrial alternative oxidase affects chloroplast function, redox status and stress response in a marine diatom

et al. 2018

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“…In Arabidopsis thaliana, five genes encode AOX isoproteins, which can be divided into two subfamilies, AOX1 (isoforms A, B, C and D) and AOX2 (Polidoros et al 2009). The expression of AOX genes is tissue-specific and depends on the developmental stage of the plant, changes in cellular metabolism as well as various biotic and abiotic stress conditions such as drought, high temperature, chilling, salinity, hypoxia and pathogen attack (Juszczuk and Rychter 2003, Millenaar and Lambers 2003, Van Aken et al 2009, Feng et al 2013, Vanlerberghe 2013. AOX1A represents the major isoform in A. thaliana.…”

Section: Introductionmentioning

confidence: 99%

Refined method to study the posttranslational regulation of alternative oxidases from Arabidopsis thaliana in vitro

Selinski

Hartmann

Höfler

et al. 2016

Physiologia Plantarum

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In isolated membranes, posttranslational regulation of quinol oxidase activities can only be determined simultaneously for all oxidases - quinol oxidases as well as cytochrome c oxidases - because of their identical localization. In this study, a refined method to determine the specific activity of a single quinol oxidase is exemplarily described for the alternative oxidase (AOX) isoform AOX1A from Arabidopsis thaliana and its corresponding mutants, using the respiratory chain of an Escherichia coli cytochrome bo and bd-I oxidase double mutant as a source to provide electrons necessary for O2 reduction via quinol oxidases. A highly sensitive and reproducible experimental set-up with prolonged linear time intervals of up to 60 s is presented, which enables the determination of constant activity rates in E. coli membrane vesicles enriched in the quinol oxidase of interest by heterologous expression, using a Clark-type oxygen electrode to continuously follow O2 consumption. For the calculation of specific quinol oxidase activity, activity rates were correlated with quantitative signal intensity determinations of AOX1A present in a membrane-bound state by immunoblot analyses, simultaneously enabling normalization of specific activities between different AOX proteins. In summary, the method presented is a powerful tool to study specific activities of individual quinol oxidases, like the different AOX isoforms, and their corresponding mutants upon modification by addition of effectors/inhibitors, and thus to characterize their individual mode of posttranslational regulation in a membranous environment.

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“…The gene expression of these isoforms is tissue specific, depends on the developmental stage of the plant, changes in cellular metabolism as well as various abiotic and biotic stress conditions, and is highly responsive to dysfunctions in the mitochondrial respiratory metabolism (Juszczuk and Rychter, 2003;Millenaar and Lambers, 2003;Zarkovic et al, 2005;Clifton et al, 2006;Van Aken et al, 2009;Feng et al, 2013;Vanlerberghe, 2013). Arabidopsis (Arabidopsis thaliana) possesses five genes encoding AOX proteins that can be divided into two subfamilies: AOX1A to AOX1D and AOX2 (Polidoros et al, 2009;Pu et al, 2015).…”

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confidence: 99%

Analysis of Posttranslational Activation of Alternative Oxidase Isoforms

et al. 2017

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ORCID IDs: 0000-0002-1247-7282 (J.S.); 0000-0001-5754-025X (J.W.); 0000-0002-6140-6181 (R.S.).Mitochondrial alternative oxidase (AOX) in plants is a non-proton-motive ubiquinol oxidase that is activated by redox mechanisms and 2-oxo acids. A comparative analysis of the AOX isoenzymes AOX1A, AOX1C, and AOX1D from Arabidopsis (Arabidopsis thaliana) revealed that cysteine residues, CysI and CysII, are both involved in 2-oxo acid activation, with AOX1A activity being more increased by 2-oxo acids than that of AOX1C and AOX1D. Substitution of cysteine in AOX1A by glutamate mimicked its activation by pyruvate or glyoxylate, but not in AOX1C and AOX1D. CysIII, only present in AOX1A, is not involved in activation by reduction or metabolites, but substitutions at this position affected activity. AOX1A carrying a serine residue at position CysI was activated by succinate, while correspondingly substituted variants of AOX1C and AOX1D were insensitive. Activation by glutamate at CysI and CysII is consistent with the formation of the thiohemiacetal, while succinate activation after changing CysI to serine suggests hemiacetal formation. Surprisingly, in AOX1A, replacement of CysI by alanine, which cannot form a (thio)hemiacetal, led to even higher activities, pointing to an alternative mechanism of activation. Taken together, our results demonstrate that AOX isoforms are differentially activated and that activation at CysI and CysII is additive.

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Expression and signal regulation of the alternative oxidase genes under abiotic stresses

Cited by 40 publications

References 98 publications

Downregulation of mitochondrial alternative oxidase affects chloroplast function, redox status and stress response in a marine diatom

Downregulation of mitochondrial alternative oxidase affects chloroplast function, redox status and stress response in a marine diatom

Refined method to study the posttranslational regulation of alternative oxidases from Arabidopsis thaliana in vitro

Analysis of Posttranslational Activation of Alternative Oxidase Isoforms

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