木薯MePYL8基因克隆及表达分析

Cloning and Expression Analysis of MePYL8 Gene in Cassava

脱落酸介导的核心信号通路在植物应答非生物胁迫的过程中具有重要功能,而PYL蛋白是该信号通路中ABA的受体,因此研究PYL家族基因有助于完善对该信号通路的理解。本研究利用PCR技术从木薯栽培种KU50中克隆得到一个PYL家族基因,命名为MePYL8,该基因的开放阅读框全长为579 bp,编码193个氨基酸。对其进行序列比对表明MePYL8与橡胶树和麻疯树中的氨基酸序列同源性最高,进化树分析显示MePYL8与拟南芥PYL8/RCAR3的亲缘关系最近。此外,利用荧光定量PCR对MePYL8进行多种处理下的表达分析,结果显示:MePYL8在转录水平受到ABA、高盐胁迫和干旱胁迫的诱导作用,同时受到氧化胁迫的抑制作用,表明MePYL8在多种非生物胁迫下的信号转导通路中可能具有重要的功能。本研究为后续深入研究该基因的功能和分子调控机制提供理论依据,为作物抗逆育种提供潜在的资源。

Abscisic acid（ABA） mediated core signaling pathway plays vital roles in plant responses to abiotic stresses,and PYL proteins are the receptor for ABA in this signaling pathway.Therefore,the research of PYL family genes can help improve the understanding of this signaling pathway.This study cloned and obtained a PYL family gene named MePYL8 from the cassava cultivar KU50 by RT-PCR method,which had a 579 bp open reading frame and encoded 193 amino acids.Multiple sequence alignment showed that the highest homology of amino acid sequences with MePYL8 mainly came from Hevea brasiliensis and Jatropha curcas.Phylogenetic tree analysis revealed that MePYL8 had the closest genetic distance with Arabidopsis PYL8/RCAR3.In addition,the expression patterns of MePYL8 under various treatments were investigated by fluorescent quantitative PCR.The result indicated that MePYL8 was induced by ABA,salt stress and drought stress,but inhibited by oxidative stress at the transcriptional level,which suggested that MePYL8 might play an important role in signal transduction pathways under various abiotic stresses.This study might provide a theoretical foundation for further investigation on the specific functions and molecular regulation mechanisms of MePYL8 and provide potential resources for stress resistance breeding of crop.