葡萄活性赤霉素合成关键基因VvGA3ox家族的克隆和表达分析

在植物赤霉素合成代谢中，GA3ox可将几种非活性赤霉素转化为具生理活性的赤霉素。以葡萄有核品种‘黑比诺’和无核品种‘无核白’为材料，克隆葡萄的VvGA3ox基因家族成员，分析基因结构、进行染色体定位和系统发育树构建，检测其组织器官表达特性和在胚珠（幼种子）发育过程的表达变化。结果表明，葡萄基因组VvGA3ox家族有3个成员，cDNA长度分别为1 313、1 225和1 480 bp，都包含2个外显子和1个内含子结构。组织器官特异性表达分析表明，VvGA3ox1在胚珠中的表达很低，在根中高表达；VvGA3ox2和VvGA3ox3在花和胚珠中的表达较高。在受精后胚珠（幼种子）发育过程中，VvGA3ox家族基因的表达趋势存在差异，其中VvGA3ox1在‘黑比诺’与‘无核白’中均是在盛花后30 d时上调之后下降；VvGA3ox2在‘黑比诺’中20 ~ 30 d极速上调之后下降，相应地‘无核白’中是先缓慢下降之后上升；VvGA3ox3在‘黑比诺’中逐渐下降，对应地‘无核白’中是在10 ~ 15 d先上升后在20 ~ 45 d呈下降趋势并逐渐与‘黑比诺’中的表达持平。VvGA3ox在有核和无核葡萄品种中表现较大差异表达，与葡萄无核性状有一定关系。

Cloning and Expression Analysis of the Key Genes Family VvGA3ox in Active Gibberellin Synthesis of Grapevine

GA3ox genes can transform several inactive gibberellin to the physiological active in plant gibberellin anabolism. VvGA3ox gene families were cloned from seed（cv. Pinot Noir）and seedless（cv. Thompson Seedless）grape varieties. We performed gene structure analysis，chromosome mapping analysis and phylogenetic analysis，and also investigated expression patterns of VvGA3ox genes in various grape organs and at different stages of ovule development. In this study，3 GA3ox genes（VvGA3ox1–VvGA3ox3）were identified in the grape genome. These 3 genes all contain two extrons and one intron  whose cDNA sequence length was 1 313，1 225 and 1 480 bp，respectively. Expression analysis of the grape VvGA3ox genes in various organs demonstrated that VvGA3ox1 exhibited a low level in ovule tissue which expressed a high level in root tissue，while VvGA3ox2 and VvGA3ox3 exhibited a higher level in flower and ovule tissues. The expression patterns of VvGA3ox genes were distinct during ovule development，VvGA3ox1 showed expression that up-regulated at the 30 DAF（day after full-bloom）and then down-regulated in cv. Pinot Noir and cv. Thompson Seedless grape. Expression of VvGA3ox2 in cv. Pinot Noir significantly up-regulated at the 20–30 DAF and down-regulated later，while the ovule expression in cv. Thompson Seedless was slowly down-regulated and then up-regulated. Expression of VvGA3ox2 in cv. Pinot Noir was gradually down-regulated. However，the expression in cv. Thompson Seedless was up-regulated at the 10–15 DAF and then down-regulated to the level that in cv. Pinot Noir. This research shows that VvGA3ox genes exist significant differences between seedless and seed varieties，which may be related to grape seedlessness.