金花茶查尔酮异构酶基因全长克隆与表达的初步研究

摘要

A full-length cDNA sequence of chalcone isomerase ( CHI) gene was obtained from petals of Camellia nitidissima using the methods of Reverse Transcription PCR and RACE, named Cn-CHI ( GenBank accession No. HQ269805. 1). Sequence analysis indicated that Cn-CHI is 953bp in full length and contains a 5'-untranslated region (5'-UTR) of 56 bp,a 3'-UTR of 204 bp,and an opening reading frame (ORF) of 693bp encoding a 230 predicted amino acids. Sequence alignment of amino acids revealed that Cn-CHI shared more than 75% homology with CHI from plants of Rosaceae, Ericaceae, Solanaceae and 99% homology with C. Sinensis. Relative real-time PCR analysis indicated that Cn-CHI showed the tendency of a sharp increase at the early stage and then decreased slowly; the highest transcript abundance in carpels, and the second in stamens, the transcript of Cn-CHI in sepals and petals were almost at the same level.%利用RT -PCR和RACE技术,从我国珍稀濒危植物金花茶花瓣中获得了查尔酮异构酶(Chalcone isomerase,CHI)基因的cDNA全长,命名为Cn-CHI,GenBank登录号HQ269805.1.碱基序列分析表明,Cn-CHI基因全长953bp,包含56 bp的5’非翻译区、204 bp的3’非翻译区和一个长为693 bp编码230个氨基酸的开放阅读框.氨基酸序列比对分析表明,Cn-CHI基因编码蛋白与蔷薇科、杜鹃花科、茄科等植物的CHI蛋白同源性都在75％以上,与山茶科山茶属茶树CHI蛋白同源性高达99％.相对荧光定量PCR分析表明,Cn-CHI基因在金花茶花蕾发育过程中呈现先急剧上升后平缓下降的趋势;在花器官的不同部位中,Cn-CHI基因表达量最高的是雌蕊,其次是雄蕊,在萼片和花瓣中的表达量较低且相差不大.