西瓜防御素基因ClPDF2.1的克隆及表达分析  

Cloning and Expression Analysis of Plant Defensin-like Gene (ClPDF2.1) from Watermelon

作　　者：张曼[1] 羊杏平[1] 王薇薇[1,2] 徐锦华[1] 刘广[1] 姚协丰[1] 李苹芳[1] 

机构地区：[1]江苏省农业科学院蔬菜研究所,南京210014 [2]江西农业大学农学院,南昌330045

出　　处：《西北植物学报》2013年第5期872-877,共6页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家西甜瓜产业技术体系(CARS-NO.8);江苏省农业科技自主创新基金[cx(11)1001];江苏省农业科学院博士后基金(006046511105)

摘　　要：该研究从西瓜中克隆了西瓜防御素基因ClPDF2.1(GenBank登录号为KC481267)。序列分析结果表明,ClPDF2.1基因开放阅读框为225bp,编码75个氨基酸,预测蛋白质分子质量为8.237kD,等电点为9.375。蛋白质结构分析表明,ClPDF2.1蛋白含有防御素特有的8个半胱氨酸结构域。进化分析显示,ClPDF2.1与拟南芥PDF2归为一类,与五彩椒的亲缘关系最近(59%)。荧光定量PCR分析表明,ClPDF2.1在西瓜根、茎、叶器官中都有表达,叶中表达量高于根,茎中表达量最低。ClPDF2.1基因的表达也受到外源植物激素水杨酸、茉莉酸甲酯、乙烯利和西瓜枯萎病菌的诱导上调,表明ClPDF2.1基因通过信号传导途径参与对西瓜枯萎病菌株的防御反应。西瓜防御素基因的克隆及表达分析为其功能鉴定奠定了基础。In this work, a defensin like cDNA sequence was cloned trom watermelon, ilaliletl （Gengank accession No. KC481267）. Bioinformatics analysis showed that CIPDF2. 1 encodes a putative polypeptide of 75 amino acids with a calculated molecular mass of 8. 237 kD and a theoretical pI of 9. 375. Sequence alignment showed that C1PDF2. 1 had high homology to known PDF proteins from other plant species and contained the conserved eight cysteines motif. Phylogenetic analysis indicated that C1PDF2. 1 belonged to the Arabidopsis PDF2 cluster,and was close to Capsicum annuutn PDF gene with an overall sequence identity of 59%. Real-time PCR analysis revealed that CIPDF2. 1 expressed in all tissues exam ined, with the highest in leaves, second in roots and the lowest in stems. Expression profiles under different treatments such as abscisic acid （SA）,methyl jasmonate （JA）,ethephon （ETH） and Fusarium wilt were compared,and the results revealed that transcriptional level of CIPDF2. 1 was obviously up-regulated. These results suggested that CIPDF2.1 is probably employed the signal pathways to defense against Fu- sarium wilt pathogen.

关 键 词：西瓜 植物防御素 基因克隆 表达分析 

分 类 号：Q786[生物学—分子生物学]