萼脊兰AGAMOUS(AG)基因的克隆与表达分析

摘要

The structure,function,clone of AGAMOUS(AG) gene as well as its expression regulation were studied in this paper.It's found that the amino acid sequence of AG belonged to plant type peculiar MIKC,C gene of MADS-box class. The full length cDNA of AG was 1 002 bp with an ORF of 702 bp encoding 233 putative amino acid residues(GenBank:KY744276). Multiple sequence alignments and phylogenetic tree analyses showed that AG was close to the phalaenopsis amabilis with an overall se-quence similarity. The encoded protein was hydrophilic and contained 48.93% of α-helical domains, 11.59% of extended strand,39.48% of random coil. The highest expression of the gene analyzed by real-time fluorescent quantitative PCR was in bud and stigma. It indicated that AG gene expression was tissue specificity,belonged to the class C gene characteristics in ABCDE model,and controlled the de-velopment of stamen and pistil.%通过对萼脊兰AGAMOUS(AG)基因进行结构、功能分析、克隆和AG基因的表达调控等方面的探究,发现,萼脊兰AG的氨基酸序列属于植物特有的MIKC型MADS-box的C类基因,该基因cDNA全长1002 bp,包含一个702 bp的开放阅读框,该基因命名为AG(登录号KY744276),共编码233个氨基酸.蛋白序列比对和进化树分析表明,AG蛋白与蝴蝶兰蛋白一致性最高,进化距离最近.二级结构分析表明,该蛋白分子属于亲水性蛋白,其中α螺旋占48.93%,延伸链占11.59%,不规则卷曲占39.48%.实时荧光定量PCR(qRT-PCR)分析表明, AG基因在花蕾和蕊柱中表达量很高,说明AG基因的表达具有组织特异性,在ABCDE模型中属于C类基因的特征非常明显,控制着雄蕊和雌蕊的发育.