黄瓜LDC基因克隆及逆境胁迫下的表达分析  

Cloning of LDC gene and its expression analysis under several adversity stresses from Cucumis sativus L.

作　　者：苗永美[1,2] 宁宇[1] 沈佳[1] 贾利[1] 李季[1] 娄群峰[1] 翁益群[3] 陈劲枫[1] 

机构地区：[1]南京农业大学园艺学院/作物遗传与种质创新国家重点实验室,江苏南京210095 [2]安徽科技学院生命科学学院,安徽凤阳233100 [3]美国威斯康星大学园艺系,威斯康星麦迪逊53706

出　　处：《南京农业大学学报》2013年第3期8-14,共7页Journal of Nanjing Agricultural University

基　　金：国家973计划项目(2009CB119001);国家自然科学基金重点项目(30830079)

摘　　要：利用RT-PCR技术从耐冷黄瓜品种‘Chipper’中克隆鉴定了1个赖氨酸脱羧酶(LDC)基因的ORF,命名为CsLDC,在GenBank中的登录号为KC202438。该基因ORF全长为645 bp,编码215个氨基酸的肽链,相对分子质量为23 625.2,等电点为5.99。BLASTp发现该蛋白具有赖氨酸脱羧酶保守序列,与毛果杨的同源性最高,进化树分析表明CsLDC与矮牵牛LDC亲缘关系最近;该蛋白无信号肽但存在一个明显跨膜区,并存在多个蛋白质位点;SWISS-MODEL预测该蛋白的3D结构与拟南芥At2G37210基因编码赖氨酸脱羧酶蛋白2a33相似性为88.89%。荧光实时定量PCR检测结果显示,CsLDC是低温和盐快速响应基因,在处理4 h时表达量达峰值,分别是处理前的4.07和2.03倍,之后下降到原来水平,并长时间维持稳定;而干旱胁迫对该基因表达起到下调作用,24 h时又恢复到原来水平,推测CsLDC在黄瓜耐低温和耐盐中起重要作用。The open reading frame （ORF）of lysine decarboxylase （LDC）was isolated and identified from chilling tolerance cucumber ＇ Chipper＇ using RT-PCR technique, named as CsLDC. The accession number was KC202438 in GenBank. The gene had an ORF of 645 bp encoding a protein of 215 amino acids,had a relative molecular mass of 23 625.2,and its isoelectric point was 5.99. The putative amino acid sequence only contained LDC conserved sequence, and shared high identity with LDC in Popilus trichocarpa. CsLDC had the nearest genetic relationship with Petunia × hybrida by phylogenetic tree analysis. The predicted protein had no signal peptide, but had an obvious transmembrane domain and multifunction site. The similartity of forecasting 3 D structure of CsLDC with SWISS-MODEL and that of 2a33 encoded by AtLDC （ At2G37210 ） was 88. 89%. The responses of CsLDC expression to low temperature and salt stress was quick by quantitative real-time PCR, and the expression of CsLDC under treatments for 4 h reached the peak, which were 4.07 and 2.03 times of that controls, then dropped to the previous levels and maintained stable. But CsLDC was inhabited by drought, and got back the original when treated for 24 h. It was speculated that the CsLDC gene might be involved in the defence against low temperature and salt resistance in cucumber seedling.

关 键 词：黄瓜 赖氨酸脱羧酶(LDC) 基因克隆 生物信息学 基因表达 

分 类 号：S642.2[农业科学—蔬菜学]