关键词: 橡胶树胶孢炭疽菌, NADPH氧化酶, 致病力

Abstract: The rubber anthrax caused by Colletotrichum gloeosporioides is the major reason resulting in the yield reduction of rubber in Hainan. Research on the molecular pathogenic mechanism of C. gloeosporioides provides theoretical basis for the control strategy on rubber anthrax. Using the homologous recombination principle and the protoplast transformation method,the mutants of the genes encoding NADPH oxidase in C. gloeosporioides deleted was constructed,and the physiological phenotypes such as its growth and pathogenicity etc. were analyzed. As results,there were three genes encoding NADPH oxidases（Nox）,including CgNoxA,CgNoxB,and CgNoxC,and the one CgNoxR encoding the regulatory protein of NADPH oxidases. PCR analysis confirmed that the mutants with above 4 genes knocked out were constructed successfully. Compared to the wild strain,the conidia and pathogenicity of the mutants varied. The mutant with CgNoxA deleted impaired conidia generation,the CgNoxR knocked-out mutant showed abnormal conidia germination behavior,and knocking out of CgNoxB led to significant decrease in the pathogenicity of the mutant to H. brasiliensis leaves. The detection by staining observation suggested that CgNoxA and CgNoxB were involved in the ROS（reactive oxygen species）metabolism. These results demonstrated that NADPH oxidases play important roles in regulating the conidia generation and pathogenicity of C. gloeosporioides.

Key words: Colletotrichum gloeosporioides, NADPH oxidases, pathogenicity