UvMPS1 Is Impormant For Vegetative Growth And Stress Responses In The Rice False Smut Fungus Ustilaginoidea Virens

Rice false smut is also known as green powder disease, green smut, false smut, valley flower disease and it is a late rice panicle diseases caused by the Ustilaginoidea virens(Cooke.) Takah.With the promotion of high-yield rice varieties and the change of field tillage measure,the disease is becoming popular all over the world and more and more serious,and it has become one of the most important diseases of rice which is harmful to the rice production and food security.With the announcement of rice aspergillus genome database,the research of gene function in this pathogen has become possible, but because the low efficiency of false smut bacteria recombination,the current research on the pathogen gene function is rarely reported.In this study,we used the Agrobacterium tumefaciens mediated transformation(ATMT) to knock out the UvMPS1 gene. We used the Ustilaginoidea virens gene knockout vector PCBDW and back mutation carrier PCBDW-GEN in our laboratory to construct UvMPS1 gene knockout vector and reversion mutation carrier; using the established ATMT,we obtained 568 transformants, and screened a UvMPS1 mutants. Through the study we found that the nutrition growth rate of UvMPS1 mutants slowed down, the hyphae of UvMPS1 mutant was more dense; compared with wild type Uv-8b, the conidia production of UvMPS1 mutant decreased 69.51% and 1% forms of variable length spores were formed, but the spore germination of UvMPS1 mutant was normal.Through the stress analysis we found that the UvMPS1 mutant had stronger toleranceis to NaCl and sorbitol, SDS and H2O2, Congo red and calcofluor; the deletion of UvMPS1 gene can affect the expression of oxidative stress related genes UvAP1, UvSKN7,UvATF1 and osmotic pressure related gene UvCTT1,Uv GPD1 in Ustilaginoidea virens. The effect of secondary metabolites in the culture filtrate of UvMPS1 gene deletion mutant on the growth inhibition of root and leaf in rice seed germination was enhanced.In this study we successfully obtained the UvMPS1 mutant and we systematically analysised the UvMPS1 mutants from the colony of nutrition growth, conidia production and germination, stress responses, cell wall integrity and the production of secondary metabolites and other aspects. These results of the study also provide certain theoretical basis for the prevention and control of the occurrence of the rice false smut.