Phytoene synthase 2 in tomato fruits remains functional and contributes to abscisic acid formation
Copyright © 2022 Elsevier B.V. All rights reserved.
| Veröffentlicht in: | Plant science : an international journal of experimental plant biology. - 1985. - 316(2022) vom: 01. März, Seite 111177 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2022
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| Zugriff auf das übergeordnete Werk: | Plant science : an international journal of experimental plant biology |
| Schlagworte: | Journal Article Abscisic acid CPTA Carotenoid biosynthesis Chromoplasts Fruit ripening Phytoene synthase Tomato Carotenoids 36-88-4 mehr... |
| Zusammenfassung: | Copyright © 2022 Elsevier B.V. All rights reserved. In ripening tomato fruits, the leaf-specific carotenoids biosynthesis mediated by phytoene synthase 2 (PSY2) is replaced by a fruit-specific pathway by the expression of two chromoplast-specific genes: phytoene synthase 1 (PSY1) and lycopene-β-cyclase (CYCB). Though both PSY1 and PSY2 genes express in tomato fruits, the functional role of PSY2 is not known. To decipher whether PSY2-mediated carotenogenesis operates in ripening fruits, we blocked the in vivo activity of lycopene-β-cyclases in fruits of several carotenoids and ripening mutants by CPTA (2-(4-Chlorophenylthio)triethylamine hydrochloride), an inhibitor of lycopene-β-cyclases. The CPTA-treatment induced accumulation of lycopene in leaves, immature-green and ripening fruits. Even in psy1 mutants V7 and r that are deficient in fruit-specific carotenoid biosynthesis, CPTA triggered lycopene accumulation but lowered the abscisic acid level. Differing from fruit-specific carotenogenesis, CPTA-treated V7 and r mutant fruits accumulated lycopene but not phytoene and phytofluene. The lack of phytoene and phytofluene accumulation was reminiscent of PSY2-mediated leaf-like carotenogenesis, where phytoene and phytofluene accumulation is never seen. The lycopene accumulation was associated with the partial transformation of chloroplasts to chromoplasts bearing thread-like structures. Our study uncovers the operation of a parallel carotenogenesis pathway mediated by PSY2 that provides precursors for abscisic acid biosynthesis in ripening tomato fruits |
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| Beschreibung: | Date Completed 15.02.2022 Date Revised 07.12.2022 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1873-2259 |
| DOI: | 10.1016/j.plantsci.2022.111177 |