The expression of VFL and VvTFL1 genes in relation to the effects of gibberellins in different organs of “Xiangfei” grapevine

The effects of gibberellins (GAs) on plant growth and the expression of VFL and VvTFL1 genes in different organs of “Xiangfei” grapevine (Vitis vinifera L.) were investigated. The endogenous GA content significantly increased in the apical bud, inflorescence and tendril after GA treatment ofgrapevine. The expression of the VFL gene was obviously reduced in the meristem of apical buds, tendrils with florets and small inflorescences after GA treatment, but VFL gene expression was clearly found during the middle and big inflorescence developmental stages. These results suggested that the exogenous GAs delayed floral development of grapevine by inhibiting VFL gene expression at the early stage of inflorescence development. VvTFL1 gene expression was detected in the meristem of apical bud and lateral bud, but not during the process of inflorescence development. After applying GAs on grapevine, VvTFL1 gene expression decreased in the apical bud. These results suggested thatexogenous GA treatments might repress differentiation of the inflorescence meristem primordia by reducing VvTFL1 expression in the apical bud but have no effect on VvTFL1 expression during floraldevelopment