盐胁迫条件下转录因子RAP2L14调控杨树生长研究

The regulation of poplar growth by transcription factor RAP2L14 under salt stress conditions

[目的]ERF(ethylene response factor)转录因子家族基因能够调控植物应答高盐等逆境胁迫,参与植物生长发育等生物学过程。RAP2L14是ERF转录因子家族重要成员,本研究旨在探究其在杨树生长及应答盐胁迫过程中的功能。[方法]利用RT-qPCR及转录组测序技术分析‘84K杨’(Populus alba×P.glandulosa)转录因子RAP2L14基因应答盐胁迫表达模式。从‘84K杨’中克隆RAP2L14基因,对RAP2L14基因编码氨基酸序列及上游2000 bp区域启动子结构进行生物信息学分析,构建RAP2L14-RNAi植物表达载体,使用农杆菌叶盘介导法获得转基因84K杨,鉴定表明获得5个RAP2L14-RNAi抑制表达杨树转基因株系。并对盐胁迫条件下转基因株系基础生长指标进行分析。[结果]RAP2L14基因cDNA全长465 bp,共编码154个氨基酸,其表达受盐胁迫诱导。RAP2L14基因上游2000 bp启动子序列含有ABRE、ARE、CGTCA-motif等11个逆境胁迫相关作用元件。盐胁迫后,RAP2L14-RNAi转基因株系的生根率及株高明显低于对照,且生根起始时间推迟了2 d。[结论]杨树ERF转录因子基因RAP2L14为盐胁迫相关基因,其抑制表达提高了转基因株系对于盐胁迫的敏感性,限制了根的发生。本研究为揭示ERF转录因子在杨树分子育种及应答逆境胁迫方面提供候选基因及基础材料。

[Objective]Ethylene response factor(ERF)transcription factors play important roles in regulating plant response to biotic and abiotic stress,such as high salinity,and participating in biological processes such as plant growth and development.RAP2 L14 is an important member of the ERF transcription factor family.The purpose of this study was to explore its functions in the growth and salt stress response of poplar.[Methods]In this study,RT-qPCR and transcriptome sequencing were used to analyze the expression pattern of transcription factor RAP2 L14 gene of’84 K poplar’(Populus Alba×P.glandulosa)in response to salt stress.RAP2 L14 gene was cloned from’84 K poplar’,and the coding sequence and upstream promoter of RAP2 L14 gene were analyzed by bioinformatics.The expression vector of RAP2 L14-RNAi was constructed,and transgenic poplars were obtained by Agrobacterium tumefaciens leaf plate mediated method.Five poplar transgenic lines of RAP2 L14-RNAi were identified.In addition,the basic growth indexes of transgenic lines under salt stress were analyzed.[Results]RAP2 L14 cDNA was 465 bp in length,encoding a total of 154 amino acids,and its expression was induced by salt stress.The2000 bp promoter sequence upstream of RAP2 L14 gene contained 11 stress-related elements,including ABRE,ARE and CGTCA-motif.After salt stress,the rooting rate and plant height of RAP2 L14-RNAi transgenic lines were significantly lower than those in the control group,and the rooting initiation time was delayed by 2 days.[Conclusion]The inhibited expression of RAP2 L14,increased the sensitivity of transgenic lines to salt stress and restricted root development.This study provided candidate genes and basic materials to further reveal the role of ERF transcription factor in poplar molecular breeding and response to adversity stress.