The Oxidative Stress Regulating Factor Yap 1 Mediates Virulence And Deoxynivalenol Biosynthesis In Fusarium

Wheat is the food crop which is only second to rice in the Plant Area and production in our country. Wheat Scab caused huge losses to wheat production, affecting the quality of wheat seriously. Fusarium is the primary strains to cause head blight of wheat, and deoxynivalenol (Deoxynivalenol, DON) produced by the bacteria poses a serious threat to food safety. DON toxin is an important pathogenic factor, which is the secondary metabolites of Fusarium graminearum, Fusarium Tritinctum, Fusarium oxysporum and other filamentous fungi bacteria. And it presents in a variety of grains (wheat, corn, barley, oats and rye) and their products widely. The generation of DON can affect the infection process. Light, pH, carbon, nitrogen, oxidative stress and other environmental factors and genes other than the synthetic gene cluster can affect the expression of toxin genes or regulate synthetic of the toxins. The vivo accumulation of reactive oxygen species (ROS) is the initial reaction for plant to defense against pathogen infection, the presence of the system of Fusarium ROS Stress has very important significance in Fusarium infection and toxin generation.In this study, we firstly knocked out the Yap1 gene by homologous recombination, and validated the obtained mutants, then we did a research of knockout mutant phenotypes, including the growth rate, spore production volume, production amount, mycelial morphology, reaction to the oxidant, and toxin-producing expression of related genes.Focus on the analysis of oxygen pressure regulation factor 1 gene Yap biology function. Through the experiment research, we get the following conclusions:1、Yap 1 has regulation function to the Fusarium spore production, lack of Yap 1 will make the spore production quantity a small rise.2、Yap 1 has effects on surface of hypha growth form, after missing Yap 1, both under normal conditions to cultivate and under the condition of oxygen pressure, mycelium surface compared with wild type, have the fold.3、Toxin-producing amount of mutant is lower than that of wild type, which means Yap 1 and toxin-producing genes interact, regulating the toxin-producing of Fusarium.4、Yapl has no obvious effect on pathogenicity of Fusarium by blade infection experiment.5、By real-time fluorescent quantitative PCR analysis of Tri gene (Tri 4, Tri5, Tri 6, Tri 10, Tri 101) and the expression of Yap 1,it is not hard to find by the chart, compared with wild type, knock-out of Yap1 is slightly expressed compared to wild type. And toxin-producing related gene Tri 4, Tri 5, Tri 6 Tri 10 are lower expressed, Tri 101 gene directly related to toxin-producing are expressed in 4 h relatively high, but then tend to be lower.Through previous literatures, Tri 6, Tri 10 are transcription factors, which can play a role by adjusting the Tri 101, but after knocking out of Yapl, how Tri 4, Tri 5, Tri 6, Tri 10, Tri 101of Tri gene cluster regulate toxin-producing, we need to do follow-up experiments to find out.