Functional Characterization Of FGSG₁1341 Gene In Fusarium Graminearum

Fusarium head blight is one of the major diseases that cause wheat yield reduction and quality decline.Fusarium graminearum is the main pathogen causing Fusarium head blight.Fusarium graminearum produce mycotoxins,which are harmful to human and animal.Therefore,it is very important to understand the molecular mechanism of pathogenesis associated gene of Fusarium graminearum for providing some information in disease resistant breeding of wheat.The MGV1 is the key gene related the cell wall integration in the MAPK signal pathway of Fusarium graminearum.The transcriptome sequencing of MGV1 deletion mutant found that FGSG₁1341 gene was significantly up-regulated in MGV1 deletion mutant compared with the wild type.GO annotation gave out that the gene product was enzyme with transferase activity in metabolic process.Because of its high association with the MGV1,we knocked out FGSG₁1341 gene to identify its function in cell wall integration of Fusarium graminearum.In this study,the knockout boxes containing hygromycin resistant gene,hph,were construct by split-marker technique and transformed into the protoplast of wild type PH-1 mediated by PEG.The transformants were selected on the medium containing Hygromycin B and the knockout mutants were confirmed by PCR positively and negatively.Finally,we obtained two knockout mutants for functional analysis.The morphological observation and infection determination revealed that there was no obvious change on the colony morphology,conidial number and morphology,sexual reproduction ability and pathogenicity compared with wild type PH-1.However,the growth of FGSG₁1341-1 colony was slower than that of PH-1.If we treat the hyphea of the FGSG₁1341-1 with theprotoplasting enzyme,the release rate of FGSG₁1341-1 protoplasts were faster than PH-1.When FGSG₁1341-1 strain was cultured at 32℃,which was much higher than usual temperature,we found that the hyphea tip of the FGSG₁1341-1 was swollen and the edge changed into transparent at 32℃.These results indicated that the deletion of the FGSG₁1341 gene influenced the integrity of cell wall structure and function.So,we inferred that FGSG₁1341 gene involved in the integration of cell wall of Fusarium graminearum.