蝴蝶兰蔗糖合成酶基因的cDNA克隆及其表达分析  

cDNA Cloning and Sequence Analysis of a Sucrose Synthase Gene From Phalaenopsis Hybrid

作　　者：李冬梅[1] 朱根发[1] 操君喜[1] 孙映波[1] 王真[1] 吕复兵[1] 

机构地区：[1]广东省农业科学院环境园艺研究所广东省园林花卉种质创新与利用重点实验室,广东广州510640

出　　处：《热带作物学报》2013年第4期662-668,共7页Chinese Journal of Tropical Crops

基　　金：广东省农业科学院院长基金项目(No.201019)

摘　　要：利用低夜温诱导的蝴蝶兰花芽的抑制消减杂交文库中分离的蔗糖合成酶基因的ESTs片段,采用RT-PCR和RACE技术,从蝴蝶兰花芽中克隆得到蔗糖合成酶基因的全长cDNA,命名为PhSUS,GenBank登录号JX162557。该基因全长2 816 bp,包含147 bp的5′非编码区、218 bp的3′非编码区和一个长度为2 451 bp编码816个氨基酸的开放阅读框。PhSUS预测的分子量为93.30 ku,等电点为5.95。蛋白同源性分析结果表明,PhSUS与兰科植物的文心兰、石斛兰和莫氏兰(Mokara)等的蔗糖合成酶有很高同源性。保守结构域分析结果表明,PhSUS含有蔗糖合成酶和葡糖基转移酶两个保守功能域及4个ADP结合位点。表达分析结果表明,PhSUS在检测的组织中都有表达,但表达丰度不同。PhSUS在花蕾发育中后期、成熟花和花器官的表达量都较营养阶段根和叶中的表达量高。PhSUS的克隆为研究其参与花芽分化和发育的表达调控奠定了重要基础。Based on the sequences of expressed sequence tags（ESTs） of a sucrose synthase gene,which obtained from a suppression subtractive hybridization（SSH） cDNA library of cool-night temperature induced floral buds of Phalaenopsis hybrid,gene-specific primers were designed to clone the full-length cDNA of the sucrose synase gene.By using reverse transcriptase-polymerase chain reaction（RT-PCR） and rapid amplification of cDNA ends（RACE）,the full-length cDNA of the sucrose synase gene was obtained from the floral buds of P.hybrid,named PhSUS,GenBank accession number JX162557.Sequence analysis indicated that PhSUS was 2 816 bp in full-length,containing a 5＇-untranslated region（5＇-UTR） of 147 bp,a 3＇-UTR of 218 bp,and an opening reading frame（ORF） of 2 451 bp encoding a 816 predicted amino acids residues.PhSUS had a calculated molecular mass of 93.30 ku and a theoretical isoelectric point of 5.95.Sequence alignment revealed that PhSUS shared 88% -94% identities with SUS proteins of the cultivars from Oncidium,Dendrobium and Mokara in Orchidaceae.Protein conserved domain searching results showed that PhSUS contained a GT1 sucrose synthase domain,a GTB type superfamily of glycosyltransferase and four putative ADP-binding pockets.Expression analyses revealed that PhSUS was expressed in all tested tissues,but showed different expression patterns in tissues examined.The transcripts of PhSUS was higher levels in the middle and later floral bud development stages,mature flowers and floral organs than in vegetative stage of roots and leaves.The cloning of PhSUS was of great importance for further studies on the expression and regulation of which was involved in the differentiation and development of floral buds.

关 键 词：蝴蝶兰 蔗糖合成酶基因 基因克隆 序列分析 基因表达 

分 类 号：S682.31[农业科学—观赏园艺]