藤稔’葡萄VvGAI基因的克隆、亚细胞定位及时空表达分析

 以‘藤稔’葡萄（Vitis vinifera × V. labrusca‘Fujiminori’）的茎、叶、花和果为试材，采用RT-PCR结合RACE技术，克隆获得1个推测为葡萄赤霉素响应因子VvGAI基因的cDNA序列，全长2 295 bp，其编码590个氨基酸。该基因在GenBank基因数据库的登录号为HQ834311。序列分析表明：VvGAI与杨树、拟南芥、水稻的同源基因的氨基酸序列相似性分别为68.56%、62.79%和54.16%。半定量与定量PCR结果都表明，VvGAI在葡萄茎尖、叶、花和果等营养与生殖器官中均有表达，但在茎尖中的表达最高，是一个与快速生长和分裂关系密切的基因。50 mg · L^-1赤霉素处理后，各阶段果实中VvGAI表达量趋势与对照基本一致，但水平低于对照，其中幼果中表达量最高。洋葱表皮细胞的瞬时表达显示，VvGAI蛋白定位于细胞核。

Cloning,Subcellular Localization and Spatiotemporal Expression of a VvGAI Gene from Grapevine'Fujiminori'

Full length cDNA sequence of potential GA response factor gene（VvGAI）was cloned from grapevine ‘Fujiminori’（Vitis vinifera × V. labrusca）using RT-PCR and rapid amplification of cDNA ends（RACE）. The sequence has been deposited in GenBank database with the accession number of HQ834311. Sequence analysis showed that the nucleotide sequence of this gene is 2 295 bp，containing a complete open reading frame that encodes 590 amino acids. Amino acid sequence analysis revealed that this potential VvGAI shared relatively high identity with the orthologs from Populus trichocarpa（68.56%），Arabidopsis thaliana（62.79%），Oryza sativa Indica Group（54.16%）. Semi-quantitative RT-PCR and fluorescent quantitative PCR analysis showed that VvGAI was expressed ubiquitously in vegetative and reproductive organs，such as shoot，leaf，flower and fruit. However，it was expressed the highest in shoot，which suggested that VvGAI could be a gene related to the rapid growth and division. Its expression in the developing fruits from treated inflorescence with GA solution was lower than that of thecontrol，about which the highest expression level was shown in young fruits. Subcellular localization assays showed that the VvGAI protein appeared in the nucleus.