玉蜀黍平脐蠕孢聚酮合酶基因BmPKS18的功能分析

Functional analysis of the polyketide synthase gene BmPKS18 in Bipolaris maydis

玉蜀黍平脐蠕孢(Bipolaris maydis)引起的玉米小斑病严重影响了玉米的产量与质量。聚酮合酶参与调控多种毒素和黑色素的合成,在植物病原真菌生长发育和致病性方面发挥重要作用。解析聚酮合酶基因在B.maydis中的作用,对玉米小斑病防治具有重要指导意义。本研究通过基因敲除与回补的方法获得了聚酮合酶基因BmPKS18敲除突变体和回补菌株。与野生型和回补菌株相比,突变体ΔBmPKS18产生白化菌落,菌丝生长速率、产孢量和孢子萌发率显著降低,分生孢子无色且长度增加,有性生殖能力存在缺陷,致病力明显减弱。结果表明,BmPKS18基因在玉蜀黍平脐蠕孢营养生长、有性和无性生殖、致病性等方面具有重要调控作用,研究结果为深入解析玉蜀黍平脐蠕孢致病机制提供重要依据。

Southern corn leaf blight(SCLB)caused by Bipolaris maydis is a serious disease on corn,which affects serious loss of the yield and the quality of corn.Polyketide synthase plays an important role in the growth,development and pathogenesis of plant pathogens by regulating the synthesis of various toxins and melanins.It is important to elucidate the roles of polyketide synthase genes in B.maydis,which can provide insights for SCLB disease control.In this study,BmPKS18 encoding polyketide synthase was knocked out,and then the complementary strain was obtained.Compared with the wild-type and complementary strain,theΔBmPKS18 mutant showed albino phenotype,significantly reduction in mycelium growth,spore production and germination rate,increasing conidia length with no pigmentation,defect in sexual reproduction and significantly reduction of pathogenicity to corn.These results demonstrated that BmPKS18 plays an important role in regulating vegetative growth,sexual and asexual reproduction,and pathogenicity of B.maydis.These results provide important basis for further elucidation the pathogenic mechanism of B.maydis.