棉花中GhTFL1a和GhTFL1c基因的表达及启动子分析

从陆地棉中克隆了磷脂酰乙醇胺结合蛋白GhTFL1a和GhTFL1c基因,并对该基因进行表达分析、启动子预测和启动子活性研究。利用启动子分析软件PlantCARE预测得出,GhTFL1a启动子区域有脱落酸响应元件、干旱诱导的MYB结合位点和顶芽特异表达响应元件等;GhTFL1c启动子区域有乙烯响应元件、干旱诱导的MYB结合位点和水杨酸响应元件。因此,将pGhTFL1a和pGhTFL1c分别构建到启动子检测载体pBI121-GUS上形成融合表达载体,通过烟草瞬时转化检测得出这2个基因的启动子都具有活性。实时荧光定量PCR分析表明, GhTFL1a和GhTFL1c在光周期处理和不同材料的陆地棉(栽培种和半野生种)中表达模式呈相反趋势。GhTFL1a基因受脱落酸(abscisic acid, ABA)、水杨酸(salicylic acid, SA)和盐胁迫诱导,而GhTFL1c可以响应赤霉素(gibberellin, GA)、SA和ABA胁迫。研究结果初步表明,GhTFL1a和GhTFL1c可能参与了植物逆境胁迫脱落酸和水杨酸响应的调控,为在棉花中进一步阐明其功能奠定了基础。

Expression and promoter activity of GhTFL1a and GhTFL1c in Upland cotton

In this study, we cloned the phosphatidylethanolamine-binding protein GhTFL1a and GhTFL1c genes from Upland cotton, and analyzed their expression and promoter activity. The results of promoter structure prediction revealed that GhTFL1a promoter contains abscisic acid (ABA) responsiveness elements, drought-induced MYB binding sites and shoot-specific expression and light responsiveness elements, and the promoter region of GhTFL1c contains ethylene-responsive element, drought-induced MYB binding sites and salicylic acid (SA) responsiveness elements. Thus, we constructed the fusion vector pBI121-GhTFL1a-GUS and pBI121-GhTFL1c-GUS, respectively. Transient transformation of tobacco showed that both promoters had the activity to drive the expression of target gene GUS. Quantitative Real-time PCR result indicated that the expression profile of GhTFL1a and GhTFL1c was opposite during different photoperiod treatments of cultivated and semi-wild cotton. Meanwhile, the expression of GhTFL1a was induced by ABA, SA, and salt (NaCl), while GhTFL1c expression was induced by SA, gibberellin (GA) and ABA. Taken together, the results suggest that GhTFL1a and GhTFL1c might be involved in the regulation of response to abiotic stresses (SA and ABA), which could provide a solid foundation for further function identification.