ABA signaling plays a key role in regulated deficit irrigation-driven anthocyanins accumulation in ‘Cabernet Sauvignon’ grape berries

Abstract Regulated deficit irrigation (RDI) induces anthocyanins biosynthesis in grape berries; however, the mechanisms involved remain unclear. Here, we compared the change in endogenous hormones in grape berries under RDI treatment and analyzed the effect of nordihydroguaiaretic acid (NDGA), an abscisic acid (ABA) synthesis inhibitor, on anthocyanins biosynthesis in grape berries under RDI treatment. ABA showed the greatest change under RDI treatment; cluster analysis revealed the shortest distance with anthocyanins content. It is noteworthy that NDGA also inhibited the increase in anthocyanins content and the expression of synthesis-related genes in grape berries. ABA promoted anthocyanins accumulation by enhancing the expression of VvMYBPA1 and VvOMT in RDI-treated grape berries. In addition, RDI mainly promoted the synthesis and accumulation of monoglycosides anthocyanins, as well as the accumulation of malvidin-3-O-glucoside and its derivatives. These results indicated that ABA signaling plays key roles in RDI-induced anthocyanins accumulation in grape berries.