Silencing of ascorbate oxidase results in reduced growth, altered ascorbic acid levels and ripening pattern in melon fruit
Copyright © 2020 Elsevier Masson SAS. All rights reserved.
| Publié dans: | Plant physiology and biochemistry : PPB. - 1991. - 156(2020) vom: 30. Nov., Seite 291-303 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , , , , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2020
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| Accès à la collection: | Plant physiology and biochemistry : PPB |
| Sujets: | Journal Article Ascorbate oxidase Ascorbic acid Cucumis melo Ethylene Ripening Ascorbate Oxidase EC 1.10.3.3 Ascorbic Acid PQ6CK8PD0R |
| Résumé: | Copyright © 2020 Elsevier Masson SAS. All rights reserved. Ascorbate oxidase (AO, EC 1.10.3.3) is a copper-containing enzyme localized at the apoplast, where it catalyzes the oxidation of ascorbic acid (AA) to dehydroascorbic acid (DHA) via monodehydroascorbic acid (MDHA) intermediate. Despite it has been extensively studied, no biological roles have been definitively ascribed. To understand the role of AO in plant metabolism, fruit growth and physiology, we suppressed AO expression in melon (Cucumis melo L.) fruit. Reduction of AO activity increased AA content in melon fruit, which is the result of repression of AA oxidation and simultaneous induction of certain biosynthetic and recycling genes. As a consequence, ascorbate redox state was altered in the apoplast. Interestingly, transgenic melon fruit displayed increased ethylene production rate coincided with elevated levels of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO, EC 1.14.17.4) activity and gene expression, which might contribute to earlier ripening. Moreover, AO suppressed transgenic melon fruit exhibited a dramatic arrest in fruit growth, due to a simultaneous decrease in fruit cell size and in plasmalemma (PM) ATPase activity. All the above, support for the first time, the in vivo AO participation in the rapid fruit growth of Cucurbitaceae and further suggest an alternative route for AA increase in ripening fruit |
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| Description: | Date Completed 19.01.2021 Date Revised 19.01.2021 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1873-2690 |
| DOI: | 10.1016/j.plaphy.2020.08.040 |