胶孢炭疽菌G蛋白α亚基CgGα2的生物学功能

摘要

G蛋白(G protein/GTP binding protein)是能与鸟嘌呤核苷酸结合,具有水解GTP生成GDP,即具有GTP酶(GTPase)活性的蛋白.G蛋白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G蛋白生物学功能的研究.本研究从胶孢炭疽菌中克隆了一个G蛋白α亚基中的基因CgGα2,该基因编码一个354个氨基酸的蛋白,合有一个G_alpha的功能域.利用同源重组的方法获得了该基因的敲除突变体,并且在此基础上得到了突变株的互补株,将两者与野生型相比,突变体表现为营养生长缓慢,产孢量减少,对NaCl和H2O2更加敏感,对SDS的耐受性增加,对致病力无明显影响.以上结果表明,CgGα2参与调控胶孢炭疽菌的营养生长及分生孢子产生,并可能与该病菌的渗透压响应及氧化应激反应有关.%G protein,which has the activity of GTPase,is able to bind to guanine nucleotide,and has the ability to hydrolyze GTP to GDP.G protein plays an important role in growth,development and pathogenicity of plant pathogens,but there has been no studies on the biological functions of G protein in Colletotrichum gloeosporioides so far.In this study,one of the G protein α-subunit gene CgGα2 was cloned from C.gloeosporioides.CgGα2 encoded a 354-amino acid protein and contained a functional domain of G_alpha.The knockout mutant of CgGα2 was obtained by homologous recombination,and the complementary strain was obtained from the knockout mutant.Compared to the wild type and complementary strain,the knockout mutant of CgGα2 resulted in slow vegetative growth,decreased conidium production,more sensitive to NaCl and H2O2,and more tolerant to SDS.CgGα2 had no effect on the virulence of C.gloeosporioides.These results suggest that CgGα2 is involved in regulating vegetative growth and conidiation,and it might also be involved in osmotic pressure and oxidative stress response of C.gloeosporioides.