甘薯耐旱和耐盐基因的挖掘和表达分析

Mining and expression analyses of genes tolerance to drought and salt stresses in sweet potato

甘薯是世界第7大粮食作物,具有产量高、营养丰富、耐干旱和盐碱等优点.通过转录组学方法,基于国内3个甘薯品种的综合转录组数据库中进行耐旱和耐盐相关转录本序列的挖掘,共获得238个转录本,随机选取9条具有全长编码序列的转录本进行PCR扩增、克隆和测序后,测定序列与组装序列相似度均高于98%,表明转录本序列是可靠的.分析这些转录本在不同甘薯品种间的表达水平时发现,耐旱基因在京薯6号中表达量普遍较高,而在徐薯18中则普遍偏低,而耐盐相关基因的差异表达模式却与之相反.利用数字基因表达谱数据进一步分析耐旱和耐盐基因在徐薯18的6个组织或生长发育阶段中的差异和特异表达,结果显示:耐旱和耐盐基因在成熟叶和膨大期块根中相对于其他组织具有高表达且差异显著.采用荧光定量PCR方法验证结果表明,耐旱和耐盐基因在徐薯18不同组织器官或发育阶段表达情况与数字基因表达谱分析结果基本一致.

Sweet potato [Ipomoea batatas] is the worlds seventh largest food crop cultivated worldwide due to its high yield, rich nutrition and strong resistance. Based on the integrated transcriptome database represented by 3 cultivars in China, totally 238 transcripts related to drought- and salt-tolerance were obtained, of which 9 transcripts with full-length open reading frame were selected randomly for cloning and sequencing. The similari- ty between assembled and cloned sequences was higher than 98 ~, demonstrating that the assembled transcripts are reliability. Moreover, the expression levels of these resistant genes among cultivars were analyzed and the results showed that the expressions of drought-tolerant genes were generally high in Jingshu 6 and relatively low in XushulS, while the salt-tolerant genes had opposite expression patterns. The digital gene expression profiling was also used for analyzing these gene expressions among six tissues and development stages of XushulS. The results displayed that these resistant genes had relatively high-expression levels in mature leaves and expanding tuberous roots. The results from q-RT PCR verified the differential expression patterns of genes detected in the digital gene expression profiling.