胡椒PnNPR1基因的克隆与表达分析

根据胡椒病程相关基因非表达子1(Nonexpressor of pathogenesis-related genes1,NPR1)基因的部分序列设计引物,运用RT-PCR方法获得其家族成员的1个全长c DNA,命名为Pn NPR1,长度1 712 bp,开放阅读框1 362 bp,编码454个氨基酸。预测Pn NPR1分子量为141.56 ku,理论等电点为4.98。该基因含有BTB/POT结构域、ANK锚蛋白重复序列、DUF和NPR1-like C等4个结构域,具有植物NPR1所共有的保守结构域。系统进化分析表明,Pn NPR1与苜蓿的同源性最高。Real-time RT-PCR结果表明,Pn NPR1在胡椒叶片、根、茎和花中均表达,在叶中的表达量最高。辣椒疫霉菌诱导后,Pn NPR1基因的表达量在抗/感2种胡椒中均出现先增加后减少的现象,并且在抗病种质中表达量较高。研究结果为Pn NPR1的功能研究提供了理论依据。

Cloning and Expression Analysis of PnNPR1 in Piper nigrum

The full-length cDNA encoding Nonexpressor of pathogenesis-related genes1(NPR1), designated as PnNPR1, was isolated from black pepper by using PCR. The sequence of PnNPR1 was 1 712 bp in length, containing a 1 362 bp open reading frame, and encoding a polypeptide of 454 amino acids with a calculated molecular weight of 114.56 ku and a pI of 4.98. The protein had four conserved domains of BTB/POT, ANK anchored protein repeat sequences, DUF and NPR1-like C. The phylogenetic analysis showed that PnNPR1 had a closer relationship with Medicago truncatala. Real time quantitative PCR analysis showed that the expressions of PnNPR1 were differentially expressed in the root, stem, leaf and flower of black pepper. When P. capsici infected, PnNPR1 was significantly higher in resistant germplasm than in susceptible germplasm, and all time point of expression of PnNPR1 were up-regulated by infected. This result would generate an important theoretical and practical significance for black pepper genetic improvements.