Tomato fruit ascorbic acid content is linked with monodehydroascorbate reductase activity and tolerance to chilling stress
2008
Stevens, Rebecca | Page, David | Gouble, Barbara | Garchery, Cecile | Zamir, Daniel | Causse, Mathilde, M. | Génétique et Amélioration des Fruits et Légumes (GAFL) ; Institut National de la Recherche Agronomique (INRA) | Sécurité et Qualité des Produits d'Origine Végétale (SQPOV) ; Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | The Hebrew University of Jerusalem (HUJ)
International audience
显示更多 [+] 显示较少 [-]英语. Quantitative trait loci (QTL) mapping is a step towards the identification of factors regulating traits such as fruit ascorbic acid content.A previously identified QTL controlling variations in tomato fruit ascorbic acid has been fine mapped and reveals that the QTL has a polygenic and epistatic architecture. A monodehydroascorbate reductase (MDHAR) allele is a candidate for a proportion of the increase in fruit ascorbic acid content.TheMDHARenzyme is active in different stages of fruit ripening, shows increased activity in the introgression lines containing the wild-type (Solanum pennellii) allele, and responds to chilling injury in tomato along with the reduced/oxidized ascorbate ratio. Low temperature storage of different tomato introgression lines with all or part of the QTL for ascorbic acid and with or without the wild MDHAR allele shows that enzyme activity explains 84% of the variation in the reduced ascorbic acid levels of tomato fruit following storage at 4 °C, compared with 38% at harvest under non-stress conditions. A role is indicated for MDHAR in the maintenance of ascorbate levels in fruit under stress conditions. Furthermore, an increased fruitMDHARactivity and a lower oxidation level of the fruit ascorbate pool are correlated with decreased loss of firmness because of chilling injury
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