花生干旱诱导型启动子Ah MYB44-11-Pro的克隆与功能分析

Cloning and functional analysis of drought-inducible promoter AhMYB44-11-Pro in peanut(Arachis hypogaea L.)

干旱是严重威胁我国花生产量与品质的主要环境因素之一。为阐明干旱胁迫响应基因AhMYB44-11的调控机制,揭示其启动子的功能,本研究从花生基因组中扩增获得该基因的启动子序列AhMYB44-11-Pro,分别构建全长及5'端部分缺失启动子的GUS融合表达载体,利用农杆菌介导的遗传转化体系,分析启动子的活性和表达模式。结果显示,相比于同源基因AhMYB44-01的启动子,AhMYB44-11-Pro具有更多的MBS、Myb-bindingsit等响应干旱胁迫的顺式作用元件;同时其拟南芥转基因阳性植株经脱水处理后GUS染色加深,GUS酶活性显著增加;表明启动子的活性受干旱胁迫诱导表达,证实AhMYB44-11-Pro是一个干旱诱导型启动子。此外, AhMYB44-11-Pro含有种子胚乳特异表达元件和赤霉素响应元件, GUS染色显示在角果发育过程中其活性呈上调趋势,由此推测AhMYB44-11可能在种子发育尤其是干物质积累过程中发挥重要作用。本研究结果将为全面解析AhMYB44的生物学功能奠定基础,也为作物抗旱遗传改良提供参考依据。

Drought is a significantly environmental factor that poses a serious threat to peanut yield and quality in China.Our study aims to elucidate the regulatory mechanism of the drought stress response gene AhMYB44-11 and uncover the function of its promoter.We isolated the promoter sequence AhMYB44-11-Pro from the peanut genome and constructed recombinant expression vectors comprising the full-length promoter and several 5'-terminal deletion promoters,each fused with the GUS reporter gene.These vectors were then introduced into plant tissue via Agrobacterium rhizogenes-mediated transformation to assess promoter activity and expression patterns.The results revealed that AhMYB44-11-Pro contains a higher number of drought-responsive cis-regulatory elements,including MBS and Myb-binding sites,compared to the promoter of its homologous gene AhMYB44-01.Furthermore,dehydration treatment significantly enhanced GUS staining and activity in AhMYB44-11-Pro transgenic Arabidopsis,indicating that the promoter’s activity is upregulated under drought stress.These findings confirm that AhMYB44-11-Pro functions as a drought-inducible promoter.Additionally,AhMYB44-11-Pro contains a seed endosperm-specific expression element and gib-berellin response elements,demonstrating an increased expression trend during pod development,as evidenced by GUS histo-chemical staining.This suggests that AhMYB44-11 may play a crucial role in seed development,particularly in dry matter accu-mulation.This research lays the groundwork for a comprehensive analysis of the biological functions of AhMYB44 and provides a valuable reference for genetically enhancing crop drought resistance.