2018年11月18日 星期日
紫丁香查尔酮异构酶基因SoCHI的克隆及表达分析
Cloning and expression analysis on chalcone isomerase gene SoCHI in Syringa oblata
2018年 第27卷 第3期 页码[11-17]
摘要

采用RACE技术从紫丁香(Syringa oblata Lindl.)花中克隆获得查尔酮异构酶基因(CHI)的cDNA全长序列,命名为SoCHI,其编码的蛋白质为SoCHI蛋白。序列分析结果表明:SoCHI基因的开放阅读框(ORF)长度为684 bp,编码227个氨基酸残基,并且,该基因全部由外显子构成,无内含子。SoCHI蛋白理论相对分子质量24 988,理论等电点pI 5.53,不稳定系数为47.58,平均亲水指数为-0.096,并包含2个氢键结合位点、2个活性催化位点和7个底物结合位点;在该蛋白质的二级结构中,α-螺旋、延伸链和无规则卷曲分别占该蛋白质氨基酸残基总数的31.7%、20.3%和48.0%。同源性比对结果表明:紫丁香与其他9种植物CHI蛋白的同源性很高(均在76%以上),与同科〔木犀科(Oleaceae)〕植物桂花(Osmanthus fragrans Lour.)和油橄榄(Olea europaea Linn.)CHI蛋白的同源性更高(达88%)。实时荧光定量PCR扩增结果表明:SoCHI基因的相对表达量在紫丁香的嫩叶中最高,在成熟叶中次之;该基因的相对表达量在紫丁香花发育过程中先上升后下降,并在花蕾期达到最高。研究结果显示:SoCHI基因编码的氨基酸序列相对保守,且其表达与紫丁香花呈色关系密切。

 

Abstract

 Fulllength sequence of cDNA of chalcone isomerase gene (CHI) was cloned from flower of Syringa oblata Lindl. by RACE technology, which was named as SoCHI, its encoding protein was SoCHI protein. The sequence analysis result shows that the length of open reading frame. (ORF) of SoCHI gene is 684 bp, which encodes 227 amino acid residues, and this gene is formed with entirely exons and without intron. The theoretical relative molecular mass of SoCHI protein is 24 988, its theoretical isoelectric point is pI 5.53, instability coefficient is 47.58, and average hydrophilic index is -0.096, which contains two hydrogen bond binding sites, two active catalytic sites, and seven substrate binding sites. In secondary structure of this protein, α-helix, extended strand, and random coil account for 31.7%, 20.3%, and 480% of total number of amino acid residues of this protein, respectively. The homology comparison result shows that there is a high homology of CHI protein in S. oblata with that in other nine species (more than 76%), and a much higher homology with that in the same family (Oleaceae) species Osmanthus fragrans Lour. and Olea europaea Linn. (up to 88%). The result of realtime fluorescence quantitative PCR amplification indicates that the relative expression level of SoCHI gene is the highest in tender leaf of S. oblata, and the second in mature leaf. The relative expression level of this gene increases firstly and then decreases during flower development process of S. oblata, and reaches the highest at budding stage. It is suggested that the amino acid sequence encoded by SoCHI gene is relatively conserved, and there is a close relationship between its expression and flower coloration of S. oblata.
 

关键词紫丁香; 查尔酮异构酶基因; 基因克隆; 序列分析; 同源性分析; 表达特性
Key wordsSyringa oblata Lindl.; chalcone isomerase gene; gene cloning; sequence analysis; homology analysis; expression characteristics
作者王蕊1,2, 李彦慧2, 郑健1
所在单位1. 北京农学院园林学院 北京林果业生态环境功能提升协同创新中心, 北京 102206; 2. 河北农业大学园林与旅游学院, 河北 保定 071000
点击量166
基金项目国家林木种质资源共享服务平台建设与运行服务项目(2005DKA21003); 城乡生态环境北京实验室建设项目(PXM2015_014207_000014)