小麦条锈菌新菌系CYR34中CDK5基因的克隆及生物信息学分析

为探究细胞周期蛋白依赖性激酶（Cyclin-dependent kinase 5，CDK5）在小麦条锈菌（Puccinia striiformis f. sp. tritici）新菌系CYR34夏孢子萌发过程的毒性作用，以天水地区小麦条锈菌新菌系CYR34夏孢子标样为试材，通过RACE克隆 CDK5基因并对其进行生物信息学分析，获得长度为706 bp，编码190个氨基酸的cDNA序列。蛋白质结构预测显示，其二级结构主要以α-螺旋为主，且具有典型的STKC激酶结构域。同源性分析显示，CDK5与小麦杆锈菌（Puccinia graminis f. sp. tritici）中的CDK5亲缘关系较近。蛋白质互作数据库预测分析发现，CDK5可以与磷酸核酮糖3-差异构酶、荚膜生物合成蛋白、鸟苷酸激酶、丝氨酸/苏氨酸特异性蛋白激酶、16S rRNA 蛋白以及肌苷-5′-单磷酸脱氢酶6个蛋白互作关系；基因时序表达发现在孢子萌发0~6 h时，基因的表达量持续下调，6 h后表现为上调，萌发10 h后为对照的1.2倍，萌发14 h后基因的表达量达趋于平台期，为对照的1.36倍。综上所述，推测细胞周期蛋白依赖性激酶CDK5在小麦条锈菌（CYR34）夏孢子萌发过程中参与了适应环境的信号调控。

Cloning and Bioinformatics Analysis of CDK5 Gene from a New Wheat Stripe Rust Strain CYR34

In this study,we explored the toxic effect of cyclin-dependent kinase 5 (CDK5) on the germination of urediospores from the newly idencified CYR34 rust strain in Tianshui.The CDK5 gene was cloned ussing RACE (Rapid Amplifiction of cDNA Ends) and analyzed through bioinformatics tools.We successfully obtained a 706 bp cDNA sequence capable of encoding 190 amino acid.The structural prediction of protein showed a predominant α spiral secondary structure,with a characteristic STKC kinase domain.The homolology analysis demonstrated that CDK5 shared a closer relationship with the CDK5 found in Puccinia graminis f.sp. tritici.Moreover,based on the prediction and the analysis of CDK5 protein interaction network using PPIs database,CDK5 was shown to interact with six proteins,including ribose phosphate-3 isomerase,capsule biosynthetic protein,guanylate kinase,serine/threonine-specific protein kinase,16S rRNA protein and inosine-5′-monophosphate dehydrogenase.Furthermore,the gene expression analysis indicated that CDK5 expression was initially down-regulated during 0-6 hours post germination (hpg) of urediospores,followed by an up-regulated after 6 hpg,reaching a peak at 14 hpg,where was 1.36 times higher than the control.This suggests that CDK5 may paly a role in the regulating environmental signals during the germination of CYR34 urediospores.