Combined metabolism and transcriptome profiling reveals the novel role of abscisic acid during grape berry ripening

Although abscisic acid (ABA) plays versatile roles at the fruit development and ripening in the non-climacteric grapevine ( Vitis vinifera ), the ABA-regulated molecular mechanisms underlying the ripening of non-climacteric grape berry are still insufficient. Here, exogenous ABA application increased endogenous ABA contents by triggering its own biosynthetic and signaling pathway, especially VvNCEDs . Transient overexpression of VvNCED2 in tomato accelerated fruit ripening and ABA accumulation. ABA treatment also significantly affected the abundance of genes participated in ethylene and auxin signaling processes and their hormones cross-regulation ultimately activated the outbreak of ripening on grape berry. Furthermore, ABA obviously improved several ripening-associated procedures, including color development, sugar accumulation and berry softening, by coordinating a lot of genes elaborated in biosynthetic pathways of anthocyanin, sugar and cell wall, respectively. ABA also extensively mediated the transcription levels of several transcription factor family (e.g. MYB, ERF, bHLH, bZIP and WRKY), indicating a involvement of ABA-mediated transcriptional regulation during berry ripening. Our results of the ABA cascade not only help us better understanding the regulation mechanism of berry ripening but also contribute to other areas of viticultural interest. • ABA improved color development, sugar accumulation and berry softening through anthocyanin, sugar and cell wall genes. • ABA affected the hormones cross-regulation of ethylene and auxin and ultimately activated the onset of ripening. • Several transcription factors involve in ABA-mediated transcriptional regulation during berry ripening.