An anthocyanin regulator from grapes, VlmybA1-2, produces reddish-purple plants

A cDNA, VlmybA1-2, for an anthocyanin regulatory gene of grape was constructed under the control of the cauliflower mosaic virus (CaMV) 35SRNA promoter and introduced into leaf disks and petioles of kiwifruit (Actinidia deliciosa) plants by Agrobacterium-mediated gene transfer. When the tissues were cultured on selection medium, red cells visible to the naked eye formed at the cut ends of the segments after approximately 2 weeks. The cells developed into calluses, adventitious buds, and reddish-purple plantlets after 2, 3, and 6 months of culture, respectively. The pigment produced in the leaves of the transformed plants was determined to be cyanidin 3-O-(2-O-beta-xylosyl)-beta-glucoside (cyanidin 3-O-sambubioside). As VlmybA1-2 can also produce red cells in tomato and eggplant, it may be useful as a visible marker to confirm efficient transformation in dicots.