Redox basis of photosynthesis inhibition at supra-optimal bicarbonate in mesophyll protoplasts of Arabidopsis thaliana
Copyright © 2023 Elsevier GmbH. All rights reserved.
| Publié dans: | Journal of plant physiology. - 1979. - 287(2023) vom: 15. Aug., Seite 154047 |
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| Auteur principal: | |
| Autres auteurs: | , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2023
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| Accès à la collection: | Journal of plant physiology |
| Sujets: | Journal Article Antioxidant defense systems Arabidopsis Bicarbonate Redox status nadp-mdh mutant vtc1 mutant Antioxidants Bicarbonates NADP plus... |
| Résumé: | Copyright © 2023 Elsevier GmbH. All rights reserved. We examined the patterns of photosynthetic O2 evolution at 1 mM (optimal) and 10 mM (supra-optimal) bicarbonate in mesophyll protoplasts of Arabidopsis thaliana. The photosynthetic rate of protoplasts reached the maximum at an optimal concentration of 1 mM bicarbonate and got suppressed at supra-optimal levels of bicarbonate. We examined the basis of such photosynthesis inhibition by mesophyll protoplasts at supra-optimal bicarbonate. The wild-type protoplasts exposed to supra-optimal bicarbonate showed up signs of oxidative stress. Besides the wild-type, two mutants were used: nadp-mdh (deficient in chloroplastic NADP-MDH) and vtc1 (deficient in mitochondrial ascorbate biosynthesis). The protoplasts of the nadp-mdh mutant exhibited a higher photosynthetic rate and greater sensitivity to supra-optimal bicarbonate than the wild-type. The ascorbate-deficient vtc1 mutant had a low photosynthetic rate and no significant inhibition at high bicarbonate. The nadp-mdh mutants had elevated activities, protein, and transcript levels of key antioxidant enzymes. On the other hand, the antioxidant enzyme systems in vtc1 mutants were not much affected at supra-optimal bicarbonate. We propose that the inhibition of photosynthesis at supra-optimal bicarbonate depends on the redox state of mesophyll protoplasts. The robust antioxidant enzyme systems in protoplasts of nadp-mdh mutant might be priming the plants to sustain high photosynthesis at supra-optimal bicarbonate |
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| Description: | Date Completed 14.08.2023 Date Revised 14.08.2023 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1618-1328 |
| DOI: | 10.1016/j.jplph.2023.154047 |