Functional Characterization Of The MGV1 Associated Gene FGSG₀9297 In Fusarium Graminearum

Fusarium head blight is a fungal disease prevalent in warm and humid areas around the world,which seriously threatens the yield and quality of wheat and other cereals.The main pathogen causing Fusarium head blight is Fusarium graminearum,and the multiple secondary metabolites produced by the fungus have a great deal of harm to crops and humans and animals.Therefore,it is very important to explore the pathogenesis of Fusarium head blight related genes through molecular biology.The MGV1 gene was knocked out on the MAPK signal pathway of Fusarium head blight,and the knockout mutant was sequenced.Compared with the wild type strain of Fusarium graminearum,there were 3791 genes expression changed,with 1729 up-regulated genes and 2062 down-regulated genes.The gene differential expression analysis showed that the expression of FGSG₀9297 gene was found to be 0 when the MGV1 gene was present.When the MGV1 gene was deleted,the expression of the gene was significantly up-regulated.GO annotation gives out that the gene exists in membrane and involves in transmembrane transport of amino acids in molecular function and biological process.Because of its high association with the MGV1,we choosed it as the study object to identify its function by gene substitution technique.In this study,we used the Split-Marker technique to construct a knockout cassette containing the hygromycin resistance gene hph.The protoplast transformation of wild type PH-1 was mediated by PEG,and the resulting transformants were selected on the medium containing hygromycin,and the knockout mutants were finally identified by PCR.The phenotypic and pathogenicity of the knockout mutants were detected.Finally,four positive knockout mutants were obtained after multiple tests.The results showed that the colony morphology,filtrate color,conidial morphology,sporulation rate and pathogenicity of △FGSG₀9297 were notchanged compared with wild type PH-1.In the growth rate,△FGSG₀9297colony initially relatively slow,then basically the same as PH-1.Finally,the release rate of △FGSG₀9297 protoplasts was slightly higher than that of wild-type PH-1,at 25 ℃,△FGSG₀9297 hyphae were thin and fractured.At32 ℃,the hyphea tip of the mutant was also enlarged and the edge of the protrusion was transparent and the mycelium was broken,indicating that the cell wall was changed in △FGSG₀9297.These results suggested that the FGSG₀9297 gene associated with MGV1 and might be involved in the synthesis of cell wall of Fusarium graminearum.