胶孢炭疽菌CgRGS4调控营养生长、渗透压响应、氧化应激反应和致病性

CgRGS4 regulates vegetative growth,osmotic pressure response,oxidative stress response and pathogenicity in Colletotrichum gloeosporioides

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,在植物病原真菌生长发育及致病过程中起着重要的作用,然而目前还未有关于胶孢炭疽菌(Colletotrichum gloeosporioides)RGS蛋白生物学功能的研究。试验利用PCR技术扩增了胶孢炭疽菌的CgRGS4基因,通过同源重组的方法获得CgRGS4基因的敲除突变体,通过表型分析初步确定了CgRGS4的生物学功能。结果表明,CgRGS4编码一个1 224个氨基酸的蛋白,包含RGS、PXA和PX功能域,该基因敲除突变体在营养相对贫瘠的条件下生长较野生型缓慢,对高渗透胁迫的耐受性增强,黑色素减少,对H_2O_2更加敏感,胞外漆酶及过氧化氢酶活性降低以及致病性减弱。由此可见,CgRGS4参与调控胶孢炭疽菌的营养生长、渗透压响应、氧化应激反应和致病性等多个过程。

Regulators of G-protein signaling（ RGS） are a kind of negative regulatory factor of G protein,which play an important role in growth development and pathogenicity of plant pathogen. However,there has been no research on biological functions of RGS in Colletotrichum gloeosporioides up to now. The aim of this study was to clone the gene of CgRGS4 and analyze its biological function in C. gloeosporioides. The CgRGS4 was cloned by PCR,and its gene-knockout mutant was obtained by homologous recombination. The biological functions of CgRGS4 were preliminarily determined through phenotypic analysis. The results showed CgRGS4 encoded a 1 224-amino acids protein,containing RGS,PXA and PX function domains. Compared with the wild type,the knockout mutant of CgRGS4 had slow growth on poor medium,enhanced tolerance to osmotic stress,low melanin content,sensitivity to H_2O_2,decrease in extracellular laccase and catalase activity,decreased pathogenicity. In conclusion,CgRGS4 is involved in regulation of vegetative growth,osmotic pressure response,oxidative stress response and pathogenicity of C. gloeosporioides.