胶孢炭疽菌CgRGS2基因的克隆及生物学功能

【目的】G蛋白信号调控因子(Regulators of G-protein signaling,RGS)是G蛋白的一类负调控因子,在植物病原菌生长发育及致病过程中发挥着重要的作用,然而目前还未有关于胶孢炭疽菌RGS蛋白生物学功能的研究。本试验的目的是克隆胶孢炭疽菌的一个RGS基因CgRGS2,并分析其生物学功能。【方法】利用PCR技术扩增CgRGS2的基因并进行生物信息学分析,利用同源重组的方法获得CgRGS2基因的敲除突变体,并在突变体的基础上获得互补株,通过表型分析确定该基因的生物学功能。【结果】通过PCR扩增获得了CgRGS2的基因,其编码一个574个氨基酸的蛋白,在N末端含有一个RGS功能域。该基因敲除突变体同野生型相比,表现为营养生长缓慢,气生菌丝浓密,分生孢子产量降低且孢子呈多端萌发,对氧化压力及SDS敏感,致病性减弱等。【结论】CgRGS2蛋白参与调控胶孢炭疽菌的营养生长,分生孢子产量及萌发,氧化应激反应及细胞壁完整性,对其致病性也具有一定的影响。

Gene cloning and biological function of CgRGS2 in Colletotrichum gloeosporioides

Abstract: Objective] Regulators of G-protein signaling (RGS) are negative regulatory factors of G protein and play important roles in growth development and pathogenicity of plant pathogen. However, biological functions of RGS in Colletotrichum gloeosporioides have not been studied so far. We cloned an RGS gene of CgRGS2 in C. gloeosporioides and analyzed its biological function. Methods] Gene CgRGS2 was cloned using PCR and analyzed. The gene-knockout mutant of CgRGS2 was obtained by homologous recombination, and the complementary strain was also built based on the mutant. Biological function of CgRGS2 was determined through phenotypic analysis. Results] CgRGS2 encoded a 574-amino acids protein, containing an RGS function domain in the N terminal. Comparing to the wild type, the knockout mutant of CgRGS2 had slow growth, thick aerial hyphae, reduced conidia with multi-end germination, sensitive to oxidative stress and SDS, decreased pathogenicity. Conclusion] Protein CgRGS2 was involved in regulation of vegetative growth, conidium production and germination, oxidative stress response, cell wall integrity and pathogenicity of C. gloeosporioides.