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期 刊 ：植物遗传资源学报 2016年 17卷 5期

关键词：心里美萝卜；花青素合成酶；基因克隆；表达分析；

Keywords:‘Xinlimei’radish, anthocyanin synthase, gene cloning, expression analysis,

摘 要 ：花青素合成酶（Anthocyanidin synthase，ANS）是植物花青素合成的关键酶 ，催化无色花色素转变成有色花色素。本文从‘心里美’萝卜‘HX12Q-49’中克隆到花青素合成酶基因RsANS（GenBank 登录号：KR262954）。该基因全长1,137 bp，包含2个外显子和1个内含子；开放阅读框1,071 bp，编码 356 个氨基酸。同源性分析显示 RsANS 蛋白与大白菜、甘蓝和芥菜 ANS 蛋白同源性较高。qRT-PCR表明RsANS 在‘心里美’萝卜5个不同发育时期均有表达，且在破肚期表达量最高。通过对花青素合成途径其它8个结构基因和3个调控基因表达进行分析，结果显示‘心里美’萝卜中bHLH转录因子在不同发育时期的表达模式与RsANS、CHI、DFR和UFGT基本一致，即在破肚期的表达量最高；WD40转录因子的表达与CHS类似，其表达量在芽期、破肚期、膨大前期和膨大盛期逐渐上升，随后在成熟期下降。

Abstract:Anthocyanin synthase (ANS) catalyzes the conversion of colorless leucoanthocyanins into colored anthocyanins, which is a key enzyme in the anthocyanin biosynthetic pathway. The RsANS gene (GenBank accession number: KR262954) was isolated from‘Xinlimei’radish‘HX12Q-49’in present study. The full length of RsANS was 1,137 bp and included 2 exons and 1 intron. The cDNA length of RsANS was 1,071 bp and encoded a polypeptide of 356 amino acids. Homology analysis showed that RsANS has close relationship with ANS from Chinese cabbage, kohlrabi and mustard. qRT-PCR validation of RsANS revealed that it was expressed at five developmental stages and reached the peak at cortex splitting stage. Furthermore, the expression level of 8 other functional genes and 3 regulatory genes at different developmental stages were investigated. The results showed that the expression pattern of bHLH transcription factor was similar to that of RsANS, CHI, DFR and UFGT, which peaked at cortex splitting stage. The expression pattern of WD40 transcription factor was similar to that of CHS, which gradually increased at seedling, cortex splitting, early expanding and rapid expanding stages, then decreased at mature stage.

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