The VAP1 gene expression in relation to GAs effect on tendrils, buds and flowers development in “Xiangfei” grapevine

The VAP1 expression and its relationship to GAs in tendrils, inflorescences and different buds of “Xiangfei” grapevine (Vitis vinifera L.) were investigated. Transcripts of VAP1 could be clearly detected in floral meristem primordia, ovule primordia, bracts of the apical buds and corolla of latent buds, but not in grown tendrils. These results suggested that VAP1 gene might affect the floral determination and the floral organ formation during development and growth of inflorescence and different buds. Applying GAs to shoot tips, tendrils, and inflorescence prolonged the length of tendrils, inflorescence and pedicels, which was due to the high immunohistochemical signals in these tissues. In addition, the expression of VAP1 could not be detected in the apical buds, latent buds, and inflorescences treated with exogenous GAs, suggesting that GAs might be one of the important plant hormones that regulated the transcripts of VAP1 during the development of latent or apical buds and floral induction in grapevine.