刺葡萄查尔酮合成酶基因CHS对不同光质的响应及转录因子调控分析

Response of Chalcone Synthase Gene(CHS)to Different Light Quality and Transcription Factor Regulation in Vitis davidii

查尔酮合成酶(chalcone synthase,CHS)是花青素合成途径的第一个关键酶,为探明CHS在不同光质下的表达模式及转录因子调控特征,以刺葡萄愈伤组织为材料,克隆了2个CHS基因(VdCHS2和VdCHS3),进行生物信息学分析和8种不同光质培养处理下的表达分析,并对CHS启动子顺式作用元件和转录因子结合位点进行预测。结果显示,VdCHS2和VdCHS3基因长度分别为1 382 bp和1 398 bp,均由2个外显子和1个内含子组成,编码蛋白均为无信号肽、定位于细胞质的亲水性蛋白。光照促进VdCHS的表达,VdCHS在短波光诱导下,先呈上调表达,当表达量达到一定水平后则呈现下调作用,而长波光抑制VdCHS的表达。靶向CHS的转录因子预测得到13个MYB成员,2个CHS启动子上存在23个MYB转录因子识别和结合元件。研究结果表明,不同光质的波长对VdCHS表达影响显著,13个MYB转录因子可能在刺葡萄花青素合成中参与CHS的转录调控。

Chalcone synthase(CHS)is the first key enzyme in anthocyanidin synthesis pathway.To explore the CHS expression pattern under different light quality and transcription factor regulation,2 CHS genes(VdCHS2 and VdCHS3)were cloned from Vitis davidii callus,and VdCHS bioinformatics and relative expression by 8 different light quality treatments were conducted.Moreover,CHS promoter cis-acting elements and transcription factor binding sites were predicted.The results showed that VdCHS2 and VdCHS3 were cloned with 1 382 bp and 1 398 bp length,respectively.Both CHS were composed of 2 exons and 1 intron,and they encoded hydrophilic proteins without signal peptide,and were predicted to be cytoplasm-located.Light promoted the expression of VdCHS,which was up-regulated under short wavelength light induction,then down-regulated when its expression level reached a certain level.But long wavelength light inhibited the expression of VdCHS.Total 13 MYB transcription factors targeted at CHS were predicted,and there were 23 MYB recognition and binding elements on the 2 CHS promoters.The above results revealed that light quality affected greatly the expression of CHS.Moreover,13 MYB transcription factors may be involved in CHS transcription regulation in anthocyanidin synthesis of V.davidii.