胶孢炭疽菌G蛋白信号调控因子CgRGS3的生物学功能

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作用。为探究胶孢炭疽病菌1个RGS基因CgRGS3的生物学功能,利用PCR技术扩增CgRGS3基因并进行生物信息学分析,通过同源重组的方法获得该基因的敲除突变体,并在突变体的基础上获得互补株,通过表型分析确定CgRGS3的生物学功能。结果表明:CgRGS3编码1个含有367个氨基酸的蛋白,包含1个RGS功能域和3个跨膜区域,表型分析发现与野生型菌株相比,敲除突变体营养生长缓慢,分生孢子产量附着胞形成率显著降低,对Cu~(2+)、Fe~(2+)、Zn~(2+)离子更加敏感,细胞壁完整性发生改变,黑色素产量降低及致病力减弱等。由此可见,CgRGS3参与调控胶孢炭疽菌的营养生长,分生孢子产生及附着胞的分化、细胞壁完整性、黑色素产生及致病性等。

Biological function of a regulator of G-protein signaling CgRGS3 in Colletotrichum gloeosporioides

Regulators of G-protein signaling (RGS) are negative control factors of G protein, which play an important role in the growth and pathogenicity of plant pathogenic fungi. In order to explore the biological function of a RGS gene CgRGS3 from Colletotrichum gloeosporioides, the CgRGS3 gene was amplified by PCR and its bioinformatics analyses were carried out. The knockout mutant of the gene was obtained by using homologous recombination, and the biological function of CgRGS3 was determined with phenotypic analyses. The results showed that CgRGS3 encoded a protein containing 367 amino acids, including a RGS domain and three transmembrane regions. Phenotypic analyses showed that the knockout mutant had slow vegetative growth, low conidial production and appressorium formation, and was susceptible to Cu²⁺, Fe²⁺ and Zn²⁺. The cell wall integrity of the knockout mutant was changed, and it also had decreased melanin production and virulence. In conclusion, CgRGS3 is involved in the regulation of vegetative growth, conidial production and appressorium formation, cell wall integrity, melanin production and pathogenicity.