黄瓜CsGPX基因克隆与细菌性角斑病胁迫下的表达分析

Cloning of Glutathione Peroxidase Gene from Cucumber and Expression Analysis after Infected by Pseudomonas syringae pv. Lachrymans

[目的]克隆CsGPX基因并研究其与黄瓜抗病性的关系。[方法]采用RT-PCR技术克隆黄瓜CsGPX基因cDNA序列全长,并对其进行生物信息学分析;采用荧光定量PCR的方法分析CsGPX基因在细菌性角斑病侵染0~96 h下的表达情况。[结果]CsGPX基因cDNA序列全长914 bp,包含一个513 bp的开放阅读框,编码170个氨基酸,该基因编码蛋白的相对分子质量约为19.02 kD,理论等电点是8.66,为亲水性蛋白,不具有跨膜结构,不含信号肽序列。实时荧光定量PCR分析表明,CsGPX在黄瓜叶中有表达。在黄瓜细菌性角斑病菌侵染下,该基因在黄瓜叶中表达增高,明显受黄瓜细菌性角斑病菌的诱导。[结论]CsGPX基因的分子鉴定为进一步解析该基因在黄瓜抗病机制方面的作用提供重要依据。

[Objective]To clone CsGPX gene and study the relationship between CsGPX gene and disease resistance of cucumber.[Method]The CsGPX gene cDNA full-length sequence was cloned by RT-PCR technology.Characteristics including the physicochemical properties and conserved domain of the deduced CsGPX protein were determined by a series of bioinformatics tools.qRT-PCR technology was performed to measure the transcript levels of CsGPX gene induced by P.syringae pv.Lachrymans.[Result]The full-length nucleotide sequence of CsGPX was 914 bp,containing a complete open reading frame of 513 bp which encoded a polypeptide of 170 amino acids.Bioinformatics analysis of the amino acid sequence showed that the molecular weight of encoded protein was 19.02 kD,and theoretical isoelectric point was 8.66.This protein was a hydrophilic protein,without transmembrane and signal peptide sequence.The expression analyses of the gene by qRT-PCR showed that the CsGPX expressd in Cucumber leaves.Induced by P.syringae pv.Lachrymans,the transcript levels of CsGPX in cucumber leaves remarkably increased with the extension of induction time.[Conclusion]This study laid a foundation for providing important basis for CsGPX gene on disease resistance mechanism of cucumber.