Functional Study Of Acetyltransferase Genes FvGcn5 And FvRtt109 In Fusarium Verticillioides

Ear rot of maize caused by Fusarium verticillioides is an important disease on maize,which produces fumonisin（FB1）that can be harmful to human and animal health.The histone acetyltransferase plays a very critical role in the regulation of eukaryotic gene expression and in various biological processes,among which the histone acetylase genes Gcn5 and Rtt109 are associated with normal cell function and growth and development.In this experiment,the basic biological functions of Fusarium acetyltransferase genes FvGcn5 and FvRtt109 were determined to provide some theoretical basis for the control of corn cob rot.The main results of the study were as follows.The main results of the study were as follows.1.Knockout mutants of histone acetyltransferase genes FvGcn5 and FvRtt109 were obtained.Knockout and back-complementation of Fusarium verticillioides genes FvGcn5 and FvRtt109 were carried out,and knockout mutantsΔFvGcn5 andΔFvRtt109 and back-complementationΔFvGcn5-C andΔFvRtt109-C were obtained.2.The histone acetyltransferase genes FvGcn5 and FvRtt109 are necessary for the vegetative growth of Fusarium verticillioides.The colony diameters of knockout mutantΔFvGcn5 andΔFvRtt109 strains were measured compared to wild-type 7600strains,and it was clear that the knockout mutantsΔFvGcn5 andΔFvRtt109 had reduced growth rates,and the marginal hyphae became curved and more branched compared to the growth rates of wild-type 7600.3.The histone acetyltransferase genes FvGcn5 and FvRtt109 are necessary for asexual reproduction of Fusarium verticillioides.The conidiospore yield was measured and it was shown that the conidiospore yields ofΔFvGcn5 andΔFvRtt109were decreased by 53.1%and 65.3%,respectively,compared with that of wild-type7600.4.The histone acetyltransferase genes FvGcn5 and FvRtt109 had the ability to affect cell wall integrity pathways,osmotic pressure,tolerance to oxidants and metal ions,and had strong resistance to the fungicide tebuconazole..The results of the external stress sensitivity assay showed thatΔFvGcn5 had enhanced tolerance to tebuconazole,Congo red,Na Cl,KCl,and Li Cl,andΔFvRtt109 had enhanced tolerance to tebuconazole and enhanced sensitivity to H₂O₂,Na Cl,and KCl.5.The histone acetyltransferase genes FvGcn5 and FvRtt109 are necessary for the biosynthesis of fumonisin in Fusarium verticillioides and have the ability to regulate the pathogenicity of Fusarium verticillioides.The inoculation results of corn ear in laboratory and corn stalk in field showed that compared with the pathogenicity of wild-type 7600 on corn ear and corn stalk,the pathogenicity ofΔFvGcn5 andΔFvRtt109 on corn ear and corn stalk was significantly reduced.The yield of fumonisin was determined and the results showed that compared with the yield of wild-type 7600 toxin,the yields ofΔFvGcn5 andΔFvRtt109 toxins were significantly decreased.These results indicated that the absence of FvGcn5 and FvRtt109 inhibited the biosynthesis of fumonisin in Fusarium verticillioides,and further led to the decline of pathogenicity of Fusarium verticillioides.6.Phenazine-1-carboxamide（PCN）was selected to further study the basic functions of histone acetyltransferase genes FvGcn5 and FvRtt109.PCN had inhibitory effect on wild-type 7600,knockout mutantsΔFvGcn5 andΔFvRtt109.Compared with wild-type 7600,the sensitivity ofΔFvGcn5 andΔFvRtt109 was increased,and the growth rate,spore germination rate,fumonisin yield and pathogenicity of the strain were significantly decreased,with significant antibacterial effect.