Studies On Polyubiquitin Gene Function Of Metarhizium Robertsii

Metarhizium robertsii is a kind of filamentous fungi that can simultaneously act on plant disease control and plant pest control.As a filamentous fungi,Metarhizium robertsii mainly has two different typical period of life history--period of conidiospore and period of mycelium.Additionally,In terms of genetic regulation mechanism,Pathogenic mechanism and biological control of entomopathogenic fungi,Metarhizium robertsii has been studied as a model organism of pathogenic fungi.Ubiquitin,A 76-amino acid and small molecular protein,is highly conserved and thermostable which is also an important gene regulates protein degradation in organism.Polyubiquitin is a highly conserved and small molecular protein which consists of different numbers of 76-amino acid in animals,Plants and filamentous fungi.Polyubiquitin mainly degrades damaged protein selectively through ubiquitination pathway,Participating in many stress responses such as drought,high temperature,high salt and heavy metal.This paper chooses Metarhizium robertsii as study object.Firstly,the author applied bioinformatics analysis on MrUBI4--gene of ubiquitin in Metarhizium robertsii;Then on the basis of the theory of homologous recombination,the author had obtained the MrUBI4 knockout strain(?MrUBI4)and the complementary strain(?MrUBI4::MrUBI4)by the use of the genetic transformation technique mediated by Agrobacterium tumefaciens;Finally,by comparing the knockout mutant strain(MT)with the wild type strain(WT),the complement mutant strain(Comp)in growth Differences in development,stress resistance,sporulation and virulence,etc.,thereby defining the specific biological function of MrUBI4.The specific findings are as follows:1.The polyubiquitin gene was analyzed in this experiment,and blast sequence analysis was performed to analyze the phylogenetic tree and protein in the ubiquitination pathway of Metarhizium robertsii.2.Knockout strains and replenishing strains of Metarhizium robertsii.3.Analysis of traits revealed that the spores of MT had obvious abnormal changes,and the growth rate and sporulation were decreased.Under the pressure of the external environment,the spore germination rate of MT was significantly reduced.Under chemical pressure stress and infestation There is no significant change in the ability of wax cocoons.In summary,the sporulation of MrUBI4 knockout strains was abnormal,the growth rate of colonies was weakened,sporulation was reduced,and spores were resistant to UV and heat stress;these results indicate that MrUBI4 is resistant to growth and development of Metarhizium spp.Stress plays an important role.