CgCDA3基因缺失对胶孢炭疽菌生长和侵染致病的影响  

Effects of knocking out CgCDA3 gene on growth and pathogenesis of Colletotrichum gloeosporioides

作　　者：孟祥春[1] 郑肖祎 黄泽鹏[1] 王小菁[2] MENG Xiang-chun;ZHENG Xiao-yi;HUANG Ze-peng;WANG Xiao-jing(Institute of Fruit Tree Research,Guangdong Academy of Agricultural Sciences/Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization,Ministry of Agriculture,Guangzhou 510640,China;College of Life Science,South China Normal University,Guangzhou 510631,China)

机构地区：[1]广东省农业科学院果树研究所/农业部南亚热带果树生物学与遗传资源利用重点实验室,广东广州510640 [2]华南师范大学生命科学学院,广东广州510631

出　　处：《江苏农业学报》2018年第5期1013-1021,共9页Jiangsu Journal of Agricultural Sciences

基　　金：国家自然科学基金项目(31301824);广东省农业厅项目(2017LM4161)

摘　　要：为了明确CgCDA3基因在胶孢炭疽菌(Colletotrichum gloeosporioides)生长及侵染致病过程中的功能,从C. gloeosporioides基因组中克隆CgCDA3基因,首先进行生物信息学分析,然后利用基因同源重组的方法获得CgCDA3基因缺失突变体(△cda3),最后分析了△cda3的孢子萌发、附着胞形成和侵染致病性变化。结果表明,CgCDA3基因ORF全长1 470 bp,编码含489个氨基酸的蛋白质,其含有一个聚多糖去乙酰化酶保守结构域。CgCDA3蛋白与已知的西瓜炭疽菌(C. orbiculare)、禾生炭疽菌(C. graminicda)和睡莲炭疽菌(C. nymphaeae)的CDA蛋白同源性较高,同源性分别为63%、60%和80%。CgCDA3基因缺失突变体同野生型相比,生长及产孢正常,但表现为孢子萌发能力下降,附着胞形成率降低,同时侵染芒果的致病性也显著减弱。推测CgCDA3基因参与调控胶孢炭疽菌孢子萌发和附着胞形成等形态生长和建成过程,从而对其致病性产生一定的影响。In order to know functions of CgCDA3 in Colletotrichum gloeosporioides development,inoculation and pathogenesis,chitin deacetylase gene CgCDA3 was firstly in silico cloned and analyzed by bioinformatics methods.Then CgCDA3 gene deficient strains(△cda3)in which CgCDA3 gene was disrupted were obtained through homologous recombination way.Finally,spore germination,appressoria formation and pathogenicity of the△cda3 strains were evaluated compared with the wild type.Results showed that the complete gene contained an open reading frame of 1 470 nucleotides which encoded a sequence of 489 amino acid residues.The gene sequence consisted of nucleotides encoding a conserved polysaccharide deacetylase function domain.The deduced amino acid sequence of the mature enzyme revealed 63%,60%and 80%similarity with a chitin deacetylase from C.orbiculare,C.graminicda and C.nymphaeae respectively.Null mutants of CgCDA3 gene were stable and showed patterns similar to the wild-type with respect to growth rate and sporulation,but decreased efficiency of spore germination and appressoria formation decreased,which was accompanied with weakened pathogenicity on mango fruit.Speculation from this research is CgCDA3 gene involved in regulating spore germination and appressoria formation of C.gloeosporioides,which is partly the reason of the decreased pathogenicity of CgCDA3 gene deficient mutant.

关 键 词：胶胞炭疽菌 几丁质脱乙酰酶 孢子萌发 附着孢 突变体 致病性 

分 类 号：S436.67[农业科学—农业昆虫与害虫防治]