Retrotransposon-Induced Mutations in Grape Skin Color

The color of grape skins is determined by the accumulation of red plant pigments called anthocyanins. White cultivars of grape are thought to have arisen from dif-ferent red cultivars by independent muta-tions (1), but the molecular bases of these color mutations are unknown. Myb-related genes (such as VlmybA1-1, VlmybA1-2, and VlmybA2) regulate anthocyanin biosynthe-sis in Kyoho, a black-skinned cultivar of Vitis labruscana (2). We show that a retrotransposon-induced mutation in VvmybA1, a homolog of VlmybA1-1, is associated with the loss of pigmentation in white cultivars of V. vinifera. Two red-skinned cultivars of V. vinif-era, Ruby Okuyama (Ru) and Flame Mus-cat (Fl), are derived by bud mutation from the…