荔枝漆酶基因LcLac的克隆与表达分析  

Cloning and Expression Analysis of the Laccase Gene from Litchi chinensis

作　　者：刘保华[1,2] 肖茜[2] 冯超[2] 孙进华[1] 王家保[1] 

机构地区：[1]中国热带农业科学院环境与植物保护研究所,海南儋州571737 [2]海南大学农学院,海南儋州571737

出　　处：《园艺学报》2012年第5期853-860,共8页Acta Horticulturae Sinica

基　　金：国家现代农业产业技术体系专项(nycytx-32-6);国家自然科学基金项目(30961740)

摘　　要：为了探明荔枝漆酶基因LcLac的表达与果皮褐变之间的关系,通过筛选‘妃子笑’荔枝果皮cDNA文库和3′-RACE技术,克隆获得了荔枝LcLac全长cDNA序列(EU527187.1)。该序列全长1779bp,5′-UTR长26bp,3′-UTR长52bp,含一个1701bp的完整开放阅读框,编码含566个氨基酸残基的多肽。该氨基酸残基序列与欧亚槭树等物种的漆酶蛋白相似性较高。荧光定量PCR结果表明,LcLac在荔枝花中表达量最高,果肉中表达量最低。在采后贮藏前期,随LcLac表达量上升果皮褐变指数升高,且褐变指数较高的‘妃子笑’果皮中LcLac表达量高于褐变指数低的‘紫娘喜’果皮。贮藏中后期严重褐变果皮中LcLac表达量比贮藏前期低。采后贮藏前期果皮中LcLac的上调表达可能对其褐变起促进作用。The relationship between postharvest browning and the expression of laccase gene（LcLac） in litchi pericarp was discussed in this work. The LcLac was cloned from‘Feizixiao’by screening cDNA libraries and 3′-RACE. The full-length cDNA sequence of LcLac was 1 779 bp in length,contained a 26 bp 5′-UTR,a 52 bp 3′-UTR and a 1 701 bp open reading frame（ORF）,which encoded a 566 amino acid polypeptide. The deduced amino acid sequence of LcLac had high identities with laccase protein from Acer pseudoplatanus. RT-PCR analysis revealed differences among the expression of LcLac,showing the highest and lowest levels,respectively,of transcripts in flower and pulp. During the early stage of postharvest storage,the browning index of pericarp increased along with the increasing expression of LcLac. Moreover,the expression of LcLac was higher in pericarp of Feizixiao（higher brown index）than Ziniangxi（lower brown index）. The expression of LcLac was decreased in severe browning pericarp during the middle and late stage of postharvest storage. The results suggested that the up-regulated expression of laccase gene in pericarp at early storage stage may contribute to the postharvest pericarp browning.

关 键 词：荔枝 果皮褐变 漆酶 基因 克隆 表达 

分 类 号：S667.1[农业科学—果树学]