辣椒疫霉CRN编码基因的克隆、转录特征及在与寄主互作中的作用  

Cloning,transcriptional profiles and roles of Phytophthora capsici CRN-encoding genes in the interaction with host plants

作　　者：陈孝仁[1] 李艳朋[1] 邢玉平[1] 徐敬友[1] 童蕴慧[1] 

机构地区：[1]扬州大学园艺与植物保护学院,扬州225009

出　　处：《植物病理学报》2015年第4期384-394,共11页Acta Phytopathologica Sinica

基　　金：国家自然科学基金(31101395);江苏省基础研究计划(自然科学基金)资助项目(BK2011443);江苏省高校自然科学研究项目(13KJB210009);江苏省普通高校研究生科研创新计划项目(KYLX_1354);国家公益性行业(农业)科研专项(201303018)

摘　　要：CRN(crinkling and necrosis-inducing protein)蛋白是一类卵菌特有的效应分子,然而目前对其功能和分子机制知之甚少。为分析CRN效应分子在辣椒疫霉(Phytophthora capsici)与植物互作中的作用,本研究利用前期转录组测序结果,对辣椒疫霉基因组数据库进行序列比对分析,获得了7个CRN编码基因的全长序列;采用RT-PCR方法分析其在辣椒疫霉生长发育阶段(菌丝、游动孢子囊、游动孢子、萌发的休止孢)和侵染寄主阶段(本氏烟(Nicotiana benthamiana)灌根1.5、3、6、12、24、36和72 h后)的转录水平,发现3个基因在辣椒疫霉生长发育阶段和侵染阶段上调表达;将这3个基因克隆测序,发现其编码蛋白均含有保守的LFLAK和HVLVVVP基序;在本氏烟上的基因瞬时表达结果表明,Pc559084和Pc570403能够抑制由致病疫霉elicitin蛋白INF1或老鼠促凋亡蛋白BAX诱发的植物程序性细胞死亡,并且Pc559084能够促进辣椒疫霉侵染植物。这些研究结果为理解CRN效应分子在辣椒疫霉致病过程中的作用提供了重要的实验数据。CRN （crinkling and necrosis-inducing protein） effectors are one class of effectors unique to oomycetes. However, their functions and molecular mechanisms in the interactions of oomycetes with host plants remain obscure. To understand the roles of these CRN effectors in the interactions between Phytophthora capsici and its host plants, a total of 7 CRN candidate genes with full lengths were obtained after blasting our previous transcriptome data against P. capsici genome database and analyzing the sequences. Transcriptional profiles of these genes were analyzed using RT-PCR approach during the stages of the pathogen development （ mycelium, sporangium, zoospore and germinating cyst） and infection of Nicotiana benthamiana roots （1.5, 3, 6, 12, 24, 36 and 72 h post-inoculation）. The results showed that three CRN-encoding genes were differentially expressed during the developmental and infection stages of P. capsici. Analyses of amino acid sequences derived from these three cloned genes demonstrated that all the sequences contain the conserved LFLAK and HVLVVVP motifs. Transient expression of the three genes in N. benthamiana displayed that two genes （Pc559084 and Pc570403） can sup- press plant programmed cell death triggered by the elicitin INF1 of Phytophthora infestans or pro-apoptotic mouse protein BAX. Furthermore, ectopic expression of Pc559084 increased susceptibility of N. bentharniana to P. capsici infection. This study provides essential experimental data for understanding the roles of CRN effectors involved in the pathogenicity of P. capsici.

关 键 词：辣椒疫霉 CRN编码基因 瞬时表达 程序性细胞死亡 毒力 

分 类 号：S436.418.1[农业科学—农业昆虫与害虫防治]