东方百合查尔酮异构酶基因 LhCHI的克隆及表达1）

摘要

The gene LhCHI encoding chalcone isomerase (CHI) involved into flavonoids synthesis was cloned from inner tepals of Oriental hybrid lily ‘Sorbonne ’ ( LhCHI, GenBank accession No .KJ784468 ) .The cDNA of LhCHI was obtained by RT-PCR and Rapid Amplification of cDNA Ends techniques .The open reading frame of LhCHI was 702 bp in length, enco-ding a protein polypeptide of 233 amino acids with a predicted molecular weight of 25 kD and a theoretical pI of 4.7.The deduced amino acid sequence of LhCHI shared 83.3%identity with CHI from Tulipa fosteriana, and contained typical con-served catalytic chalcone elements .Quantitative real-time PCR analyzed the expression profiles of LhCHI in different tis-sues.LhCHI was constitutively expressed in root , stem, leaf, bulb, tepal, anther, style and stigma with particularly high expression in flowers .The expression level of LhCHI in later stage flowers is generally higher than that in the early stage flowers.%利用RT－PCR结合RACE的方法从东方百合‘索邦’花被片中克隆了查尔酮异构酶（CHI）基因，命名为LhCHI（GenBank登录号为KJ784468）。该基因开放阅读框702 bp，编码233个氨基酸，预测该蛋白相对分子质量25 KD，等电点（ pI）为4．7。同源比对和系统进化分析表明，LhCHI基因编码的氨基酸序列具有查尔酮异构酶典型的催化活性保守位点，与百合科郁金香（ Tulipa fosteriana）查尔酮异构酶序列一致性为83．3％。半定量PCR和荧光实时定量PCR分析结果表明，LhCHI基因在百合的根、茎、叶片、鳞茎、开放花被片、花药以及柱头中均有表达，花器官中相对表达量较高，花发育后期的柱头、花柱、花被片等组织中LhCHI基因表达水平普遍高于花发育早期。