Characterization Of FgCPKA Gene In Fusarium Graminearum

Fusarium graminearum is one of the most important fungal pathogens, which causes Fusarium head blight or scab in warm and humid and semi-humid area of the world. In recent years, this disease bursts in Europe, Asia and North America and also is the major wheat disease in China. It seriously reduces the quality and yield of wheat. Fusarium graminearum infects not only the wheat, but also other plants, such as barley, oats, rye, rice, maize, sorghum. Moreover, it produces the mycotoxins, such as zearalenone and deoxynivalenol which causes fever, vomiting, diarrhea and abortion for human or animal by eating uncarefully. Commonly, chemical fungicide is used for prevention and treatment of Fusarium head blight. But from the food safety and environment protection, developing effective biological method or cultivating resistant wheet variety to the pathogen based on the principle of the molecular biology has more important significance.In this study, the deletion cassette of FgCPKA gene of Fusarium graminearum was constructed by Split-marker strategy. After transformation mediated by PEG method into the protoplast of wild type PH-1 strain, positive transformants were selected on the medium containing hygromyin. To obtain the real knock-out mutant, positive and negative screening by PCR and Southern blot analysis were carried out for the 6 single-spored transformants. The positive knock-out mutant obtained was applied to be observed the phenotype and analyzed the function of the FgCPKA gene.TheΔfgcpka mutant is significantly different from the wild type strain. The hyphea of the mutant is short and dense and the growth rate of it is much less than wild-type strains. In the CMC liquid medium, the number of spore of theΔfgcpka mutant is less than the wild-type strains. Test of the sexual reproduction demonstrated that theΔfgcpka mutant produces a small amount of perithecia in the carrot medium. Virulence assay showed that when the cornsilk was completely infected by the wild-type strain, theΔfgcpka mutant was only a little, suggesting that pathogenicity of theΔfgcpka was significantly reduced and FgCPKA was an important pathogenic gene.The experiments explored the basic functions of the FgCPKA gene and offer some clues for elucidating the molecular mechanism of pathogenesis of Fusarium graminearum.