盐胁迫下棉属野生种旱地棉(Gossypium aridum)差异表达基因的cDNA-AFLP分析

摘要

In this study, we used a salt-tolerant diploid G. Aridum species and the salt-sensitive G. Hirsutum cultivar Sumian 12 to investigate differential expression in the presence of salt stress. Using cDNA-AFLP, 25 transcript-derived fragments(TDFs) were isolated and confirmed to be present only in salt tolerant species G. Aridum under salt-stressed conditions. BLAST analysis with sequences assembled using an in-silico approach demonstrated that 23 of the cDNA fragments had homology to known proteins. The up-regulated genes were mainly involved in ion transport, ROS scavenging, cell signaling, cell division, transcription regulation, membrane protection, and penetration regulation. Quantitative real-time PCR(qRT-PCR) was used to analyze the expression patterns of nine of the 23 TDFs at different stages of salt stress in the tolerant species G. Aridum. Their expression showed a significant increase and reached a peak between 12 - 24 h of stress. These TDFs may serve as useful resources for future research on molecular mechanisms of salt stress response in cotton.%以一个耐盐的二倍体野生种旱地棉和对盐敏感的陆地棉栽培种苏棉12号为材料,运用cDNA-AFLP技术,比较两个材料分别在盐胁迫前后的表达情况,获得了25个仅在旱地棉盐胁迫下特异表达的转录片段(TDF).将这些片段进行电子克隆,延伸后的序列进行BLAST分析,结果显示23个转录片段推断的氨基酸序列与已知的蛋白同源,这些盐诱导表达的基因主要涉及离子转运、活性氧清除、细胞信号传导、细胞分裂、转录调节、膜保护、渗透调节等功能蛋白.从23个差异表达的转录片段中选择9个进行实时定量PCR(qRT-PCR)分析,结果表明这些基因在盐胁迫后表达显著增强,而且多数在12～24h达到高峰.这些cDNA克隆是开展棉花耐盐性分子基础研究的重要资源.