Mg-dechelation of chlorophyll a by Stay-Green activates chlorophyll b degradation through expressing Non-Yellow Coloring 1 in Arabidopsis thaliana
Copyright © 2018 Elsevier GmbH. All rights reserved.
| Publié dans: | Journal of plant physiology. - 1979. - 222(2018) vom: 10. März, Seite 94-102 |
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| Auteur principal: | |
| Autres auteurs: | , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2018
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| Accès à la collection: | Journal of plant physiology |
| Sujets: | Journal Article Arabidopsis thaliana Chlorophyll degradation Stay green Arabidopsis Proteins Chloroplast Proteins Membrane Proteins SGR1 protein, Arabidopsis Chlorophyll 1406-65-1 plus... |
| Résumé: | Copyright © 2018 Elsevier GmbH. All rights reserved. The first step in chlorophyll a degradation is the extraction of the central Mg. This reaction is catalyzed by Mg-dechelatase encoded by Stay-Green (SGR) in land plants. SGR extracts Mg from chlorophyll a but not from chlorophyll b, and chlorophyll b must be converted to chlorophyll a before degradation. The first reaction of the chlorophyll b to chlorophyll a conversion is catalyzed by chlorophyll b reductase. Non-Yellow Coloring 1 (NYC1) and NYC1 like (NOL) are isozymes of chlorophyll b reductase. When SGR was transiently overexpressed in Arabidopsis, both chlorophyll a and b were degraded, suggesting that the chlorophyll b to chlorophyll a conversion is activated by SGR overexpression. To examine the involvement of chlorophyll b reductases in SGR-induced chlorophyll b degradation, SGR was transiently overexpressed in nyc1, nol, and nyc1 nol double mutants by dexamethasone treatment. It was found that in the wild type and nol mutant, chlorophyll a and b were degraded and all the chlorophyll-binding proteins decreased. Meanwhile, in nyc1 and nyc1 nol mutants, chlorophyll b degradation was suppressed and the light-harvesting complex of photosystem II remained. The mRNA and protein levels of NYC1 increased after SGR overexpression in wild type plants. These results suggest that Mg-dechelation of chlorophyll a by SGR activates chlorophyll b degradation by inducing the expression of NYC1. This is an effective regulation of a metabolic pathway |
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| Description: | Date Completed 20.08.2018 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1618-1328 |
| DOI: | 10.1016/j.jplph.2018.01.010 |