Comparison among ‘Benitaka’ grape, ABA-treated ‘Benitaka’, and its deeper-colored bud mutation revealed the coloring mechanisms on grapes

ABSTRACTTo investigate the deeper coloring mechanism of berry, the ‘Benitaka’ (Be) grape, ABA treatment on ‘Benitaka’ (Be (ABA)), and its deeper coloring bud mutation ‘Brasil’ (Br) grape were compared three weeks post-ABA treatment (11 weeks post-flowering, 200 mg/g ABA). Firstly, the ABA-treated group exhibited a deeper coloring at three weeks post-ABA treatment than the ‘Brasil’. Deeper color in ‘Brasil’ was caused by higher content of peonidin-3-O-monoglucoside, malvidin-3-O-monoglucoside, and malvidin-3-O-coumarylglucoside, while the deeper color in ABA-treated group was mainly caused by higher content of cyanidin-3-O-monoglucoside and peonidin-3-O-monoglucoside. In addition, the results revealed that ‘Brasil’ showed deeper coloring than ‘Benitaka’ was probably due to the higher expression of the VvmybA1 and VvmybA1-1 genes, similar with ABA-treated group. Compared with ‘Benitaka’, the distinction between the ABA-treated group and ‘Brasil’ was the expression of VvmybA1 gene. The gene expression was de...