关键词: 葡萄, GAMYB, miR159, 赤霉素, 花发育, 基因表达

Abstract: VvGAMYB plays an important role in grape flower development. A MYB transcription factor gene in gibberellic acid（GA）signaling pathway，designated as VvGAMYB，was cloned using homology-based cloning and reverse transcription-PCR（RT-PCR） from Vitis vinifera L.‘Wink’. The open reading frame of VvGAMYB was 1 680 bp，encoding a protein of 559 amino acids. Sequence alignement showed that VvGAMYB protein contained a highly conserved R2R3 domain. In addition，VvGAMYB also contained 3 conserved motifs Box1，Box2 and Box3，which are typical structures in the GAMYB family. The VvGAMYB protein was mainly localized in the nucleus of onion epidermal cell. The expression of VvGAMYB and its downstream gene VvLFY increased and subsequently decreased during the development of grape flower. The GA3 treatment induced the expression of VvGAMYB and VvLFY，which promoted the development of grape flower. VvGAMYB was the target gene of miR159，and its expression was regulated by miR159. The miR159 could negatively regulate expression of VvGAMYB by cleavage. The expression of miR159 and its target gene VvGAMYB showed a negative correlation，and its expression was decreased by GA3 treatment，which also reduced the cleavage of VvGAMYB. These results suggest that VvGAMYB might paly a crucial role in grape flower development through the gibberellin pathway. In this process，the expression of miR159 was down-regulated while VvGAMYB and VvLFY was up-regulated.

Key words: grapevine, GAMYB, miR159, gibberellic acid, flower development, gene expression