Redox Regulation of Monodehydroascorbate Reductase by Thioredoxin y in Plastids Revealed in the Context of Water Stress
Thioredoxins (TRXs) are key players within the complex response network of plants to environmental constraints. Here, the physiological implication of the plastidial y-type TRXs in Arabidopsis drought tolerance was examined. We previously showed that TRXs y1 and y2 have antioxidant functions, and he...
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-12-01
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| Series: | Antioxidants |
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| Online Access: | https://www.mdpi.com/2076-3921/7/12/183 |
| _version_ | 1797709414816284672 |
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| author | Hélène Vanacker Marjorie Guichard Anne-Sophie Bohrer Emmanuelle Issakidis-Bourguet |
| author_facet | Hélène Vanacker Marjorie Guichard Anne-Sophie Bohrer Emmanuelle Issakidis-Bourguet |
| author_sort | Hélène Vanacker |
| collection | DOAJ |
| description | Thioredoxins (TRXs) are key players within the complex response network of plants to environmental constraints. Here, the physiological implication of the plastidial y-type TRXs in Arabidopsis drought tolerance was examined. We previously showed that TRXs y1 and y2 have antioxidant functions, and here, the corresponding single and double mutant plants were studied in the context of water deprivation. TRX y mutant plants showed reduced stress tolerance in comparison with wild-type (WT) plants that correlated with an increase in their global protein oxidation levels. Furthermore, at the level of the main antioxidant metabolites, while glutathione pool size and redox state were similarly affected by drought stress in WT and <i>trxy1y2</i> plants, ascorbate (AsA) became more quickly and strongly oxidized in mutant leaves. Monodehydroascorbate (MDA) is the primary product of AsA oxidation and NAD(P)H-MDA reductase (MDHAR) ensures its reduction. We found that the extractable leaf NADPH-dependent MDHAR activity was strongly activated by TRX y2. Moreover, activity of recombinant plastid Arabidopsis MDHAR isoform (MDHAR6) was specifically increased by reduced TRX y, and not by other plastidial TRXs. Overall, these results reveal a new function for y-type TRXs and highlight their role as major antioxidants in plastids and their importance in plant stress tolerance. |
| first_indexed | 2024-03-12T06:37:09Z |
| format | Article |
| id | doaj.art-7d705b4af4914a5ab108d442035832ae |
| institution | Directory Open Access Journal |
| issn | 2076-3921 |
| language | English |
| last_indexed | 2024-03-12T06:37:09Z |
| publishDate | 2018-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Antioxidants |
| spelling | doaj.art-7d705b4af4914a5ab108d442035832ae2023-09-03T01:16:26ZengMDPI AGAntioxidants2076-39212018-12-0171218310.3390/antiox7120183antiox7120183Redox Regulation of Monodehydroascorbate Reductase by Thioredoxin y in Plastids Revealed in the Context of Water StressHélène Vanacker0Marjorie Guichard1Anne-Sophie Bohrer2Emmanuelle Issakidis-Bourguet3Institute of Plant Sciences Paris-Saclay (IPS2), UMR Université Paris Sud—CNRS 9213—INRA 1403, Bât. 630, 91405 Orsay CEDEX, FranceInstitute of Plant Sciences Paris-Saclay (IPS2), UMR Université Paris Sud—CNRS 9213—INRA 1403, Bât. 630, 91405 Orsay CEDEX, FranceInstitute of Plant Sciences Paris-Saclay (IPS2), UMR Université Paris Sud—CNRS 9213—INRA 1403, Bât. 630, 91405 Orsay CEDEX, FranceInstitute of Plant Sciences Paris-Saclay (IPS2), UMR Université Paris Sud—CNRS 9213—INRA 1403, Bât. 630, 91405 Orsay CEDEX, FranceThioredoxins (TRXs) are key players within the complex response network of plants to environmental constraints. Here, the physiological implication of the plastidial y-type TRXs in Arabidopsis drought tolerance was examined. We previously showed that TRXs y1 and y2 have antioxidant functions, and here, the corresponding single and double mutant plants were studied in the context of water deprivation. TRX y mutant plants showed reduced stress tolerance in comparison with wild-type (WT) plants that correlated with an increase in their global protein oxidation levels. Furthermore, at the level of the main antioxidant metabolites, while glutathione pool size and redox state were similarly affected by drought stress in WT and <i>trxy1y2</i> plants, ascorbate (AsA) became more quickly and strongly oxidized in mutant leaves. Monodehydroascorbate (MDA) is the primary product of AsA oxidation and NAD(P)H-MDA reductase (MDHAR) ensures its reduction. We found that the extractable leaf NADPH-dependent MDHAR activity was strongly activated by TRX y2. Moreover, activity of recombinant plastid Arabidopsis MDHAR isoform (MDHAR6) was specifically increased by reduced TRX y, and not by other plastidial TRXs. Overall, these results reveal a new function for y-type TRXs and highlight their role as major antioxidants in plastids and their importance in plant stress tolerance.https://www.mdpi.com/2076-3921/7/12/183thioredoxinmonodehydroascorbate reductasewater stressprotein oxidationantioxidantsascorbateglutathione |
| spellingShingle | Hélène Vanacker Marjorie Guichard Anne-Sophie Bohrer Emmanuelle Issakidis-Bourguet Redox Regulation of Monodehydroascorbate Reductase by Thioredoxin y in Plastids Revealed in the Context of Water Stress Antioxidants thioredoxin monodehydroascorbate reductase water stress protein oxidation antioxidants ascorbate glutathione |
| title | Redox Regulation of Monodehydroascorbate Reductase by Thioredoxin y in Plastids Revealed in the Context of Water Stress |
| title_full | Redox Regulation of Monodehydroascorbate Reductase by Thioredoxin y in Plastids Revealed in the Context of Water Stress |
| title_fullStr | Redox Regulation of Monodehydroascorbate Reductase by Thioredoxin y in Plastids Revealed in the Context of Water Stress |
| title_full_unstemmed | Redox Regulation of Monodehydroascorbate Reductase by Thioredoxin y in Plastids Revealed in the Context of Water Stress |
| title_short | Redox Regulation of Monodehydroascorbate Reductase by Thioredoxin y in Plastids Revealed in the Context of Water Stress |
| title_sort | redox regulation of monodehydroascorbate reductase by thioredoxin y in plastids revealed in the context of water stress |
| topic | thioredoxin monodehydroascorbate reductase water stress protein oxidation antioxidants ascorbate glutathione |
| url | https://www.mdpi.com/2076-3921/7/12/183 |
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