西瓜ClPDF2.6基因的鉴定与表达谱分析  

Identification and expression analysis of ClPDF2.6 gene in 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,江苏南京210014 [2]江西农业大学农学院,江西南昌330045

出　　处：《江苏农业学报》2013年第4期831-836,共6页Jiangsu Journal of Agricultural Sciences

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项目[CX(11)1001];江苏省农业科学院博士后基金项目(006046511105)

摘　　要：为了明确西瓜防御素基因在防御反应中的作用,本研究从西瓜中分离出类防御素基因ClPDF2.6(GenBank登录号KC481272),并利用实时荧光定量PCR检测该基因在西瓜不同器官及不同胁迫处理条件下的表达情况。结果显示,从西瓜中克隆到开放阅读框(ORF)全长为225 bp的ClPDF2.6 cDNA序列,编码74个氨基酸,该序列具有植物防御素蛋白质的特异性结构特征,即含有8个保守的半胱氨酸。系统进化分析结果显示,ClPDF2.6与拟南芥PDF2类蛋白质聚为一类。ClPDF2.6基因在西瓜不同器官中都有表达,其中以叶中表达量最高;在水杨酸、茉莉酸和乙烯利胁迫下表达模式存在差异,但均上调表达,且表达量显著高于未进行胁迫处理的对照;枯萎病菌侵染下ClPDF2.6基因表达下调。表明激素等信号分子在激活ClPDF2.6基因的表达中起重要作用。To investigate the underlying molecular mechanism of watermelon defensin gene, a defensin-like gene ClPDF2. 6 （GenBank accession No. KC481272） was isolated from watermelon, and its transcription in different organs and under various stresses were analyzed using real-time PCR. The results showed that, ClPDF2. 6 contained a 225-bp open reading frame （ORF） encoding 74 amino acids. Alignment of ClPDF2. 6 with other plant defensins revealed that ClPDF2. 6 had 8 conserved cysteines, which was the potential substrate for plant defensin proteins. Phylogenetic analysis suggested that ClPDF2.6 belonged to the family of Arabidopsis PDF2. Real time PCR analysis revealed that ClPDF2. 6 was expressed constitutively in all organs of watermelon, with the highest expression in leaves. The expression of ClPDF2. 6 was up-regulated under abscisic acid （SA）, methyl jasmonate （JA） and ethephon （ETH） stresses, and was down-regulated in watermelon infected with Fusarium wilt. The results suggested that the signaling molecules played an important role in the activation of ClPDF2. 6 gene in watermelon.

关 键 词：西瓜 植物防御素 表达 逆境胁迫 

分 类 号：S651[农业科学—果树学]