东方百合LiMYB2基因克隆及表达分析

Cloning and Expression Analysis of Oriental Lily LiMYB2 Gene

MYB转录因子在植物次生代谢调控中发挥重要作用,但是对于其参与百合花香调控的影响尚不明确。本研究利用RT-PCR技术从东方百合‘索邦’中克隆了一个MYB基因家族成员LiMYB2,对其基因序列和蛋白结构、亚细胞定位以及表达模式进行了详细分析。LiMYB2基因开放阅读框(open reading frame, ORF)长度为573 bp,共编码190个氨基酸;网站预测LiMYB2蛋白无跨膜结构域;蛋白进化分析显示其与拟南芥(Arabidopsis thaliana)的At MYB21和AtMYB24同源性较高,亚细胞定位表明LiMYB2定位于细胞核。采用实时荧光定量PCR对LiMYB2在百合花器官不同部位和百合开花进程的5个时期表达量进行分析,结果表明其在花药、花丝、柱头、花瓣这几个部位都能表达,尤其在花药、柱头和花瓣中的表达量较高;LiMYB2在百合开花进程的五个时期里表达量从高逐渐降低,在花朵半开期至盛开期表达量骤降,随着花朵的衰败达到最低值。本研究表明,LiMYB2基因可能参与百合花香物质合成和释放的调控。

MYB transcription factors play an important role in the regulation of plant secondary metabolism,but the impact of their involvement in the regulation of lilium floral fragrance is unclear.In this study,a MYB gene family member,LiMYB2,was cloned from Oriental lilium'Sorbonne'by RT-PCR,and its gene sequence and protein structure,subcellular localization and expression pattern were analyzed in detail.The Open Reading Frame(ORF)of LiMYB2 gene is 573 bp in length and encodes 190 amino acids;the website predicts that LiMYB2 protein has no transmembrane structural domain;the protein evolutionary analysis shows that it has high homology with AtMYB21 and AtMYB24 of Arabidopsis thaliana,and the subcellular localization indicates that LiMYB2 is located in the nucleus.The expression of LiMYB2 in different parts of lily flower organs and five stages of lily flowering process was analyzed by real-time fluorescence quantitative PCR.The results showed that LiMYB2 could be expressed in anther,filament,stigma and petal,especially in anther,stigma and petal;the expression of LiMYB2 gradually decreased from high to low in the five stages of lily flowering process,and dropped sharply from the half-blooming stage to the blooming stage,reaching the lowest value with the decline of flowers.This study shows that LiMYB2 gene may be involved in the regulation of the synthesis and release of lily fragrance substances.