Expression of genes involved in ethylene and abscisic acid metabolism and early ripening for Yaghooti grape of Sistan

Abstract

ObjectiveGiven that grape is of economic importance, some studies are needed to examine different aspects of the processes causing early ripening. In this study, the genes involved in metabolism of the hormones were investigated which are effective in early ripening process of grape. MethodsTwo genes of SEP1 and NCED6 were selected as early ripening genes and the GAPDH was selected as the reference gene. The expression of these genes was investigated in different physiological stages and in leaf samples of early and late repining cultivars of Sistan grape. ResultsThe results showed that SEP1 gene expression (related to the ethylene transfer signal) was increased in the late ripening cultivars (Fakhri and Cheshm gavi) significantly during the processing stage and there is a significant difference in two stages of berry filling and ripening; whereas this gene was down-regulated in Red Yaghooti cultivar. The results also showed that the level of expression of NCED6 (ABA synthesis) was higher in the stage of ripening compared to the unripe stage in all cultivars; the up-regulation was much higher in late ripening cultivars. It seems that the expression of these two genes is necessary for ripening process in grape. SEP1 and NCED6 are necessary to initialize the veraison stage and to complete ripening process, respectively. The two genes, SEP1 and NCED6, can be considered to improve Yaghooti grape as early ripening to escape environmental stresses.