| Magnaporthe oryzae is a devastating rice pathogenic fungus that causes regional reduced rice production or even no crop.With the continuous growth of the world's population and the reduction of cultivated land area,the surge in food demands.However,due to the variable race of M oryzae,breeding resistant varieties or pharmaceutical control is not the best way to prevent rice blast.In recent years,the complete genome sequence of M.oryzae has been published,and the research on molecular mechanism of its pathogenicity is becoming more and more extensive.It is a scientific basis for exploring new and reliable pharmaceutical targets to control rice blast and guarantee rice yield.The transcriptional process,which regulates the expression of downstream genes by transcription factors,is an important biological process in which cells respond to physiological or environmental stimuli to carry on differentiation and development.Zinc finger structure transcription factor is the transcription factor that is most widely distributed and the most widely studied in fungi.Our previous study demonstrated that the transcription factor MoMsn2 plays important roles in growth,conidiation,stress responses,cell wall integrity and virulence by modulating the transcription levels of a series of genes in Magnaporthe oryzae.However,its regulatory mechanism was unclear.Studying its downstream regulatory gene function and regulation mechanism is of great significance to explore the pathogenesis of M.oryzae and other biological processes.Here,we identified by proteomic analysis a 3-methylglutaconyl-CoA hydratase-encoding gene,named MoAUH,which is downregulated in the ?Momsn2 mutant.Auh is present in many eukaryotes as a mitochondrial protein involved in regulation of the normal development of human cells.Auh is conserved in various species,working as a mitochondrial protein to control the synthesis respiratory complexes and the binding of RNA.However,no study of Auh proteins in phytopathogens has been reported to date.In this study,we demonstrated that MoAUH is a target of MoMsn2,and its binding site is different from that in yeast.Targeted deletion of MoAUH led to a reduction in growth,increased conidial production,alterations of the stress response and cell wall integrity and attenuation of virulence,most similar to the ?Momsn2 mutant.Further investigation revealed that MoAuh is localized in mitochondria and modulates the mitochondrial fusion/fission balance,and mitophagy,which is essential for infectious hyphal growth of the pathogen.Overall,our results provide new evidence for the regulatory mechanisms of MoMsn2,which targets the promoter of MoAUH to modulate its transcript levels,thereby disturbing the mitochondrial fusion/fission balance.This ultimately affects the development and virulence of the rice blast fungus.Fusarium head blight(FHB)caused by Fusarium graminearum is a devastating fungal disease.Recent years,the annual loss of wheat yield is increasing,and the occurrence of FHB is increasing year by year with the change of climate and agricultural farming system.Its incidence area was even as high as 80%,its outbreak caused serious decline in production and huge economic losses,such as in 2012 10 billion yuan of economic lossing in China.Apart from this,toxins production,for example,DON,ZEA,are extremely stable in humans and animals,and even carcinogenic,teratogenic,endangering the lives of organisms.However,due to the variable race of F.graminearum and environmental burden,pharmaceutical control is not the best way to prevent FHB.Therefore,it is very urgent and necessary to study the pathogenic mechanism of F.graminearum.There are a series of membrane structure organelles in eukaryotic cells.Vesicular transport plays an irreplaceable key guiding role for the transport of a series of macromolecules,including proteins,between different organelles.SNARE protein works as an vital role in the vesicle transport.According to their positioning mode,SNARE protein can be divided into the following two categories:v-SNARE protein,which located on the transport vesicle,t-SNARE protein,which located on the target membrane.In Saccharomyces cerevisiae,Sso1 is a t-SNARE protein,which involves in membrane fusion.In this study,we explored the basic function of a SNARE protein FgSsol in F.graminearum and we found ?Fgssol can not produce lush aerial mycelium,what's more,its sporulation capacity also appears to a certain degree of decline.And the DON-type toxins synthesis capacity of mutant strain decreased,Fusarium graminearum pathogenicity shows a large degree of damage.The above results indicate that FgSso1 plays an important role in vegetative growth,asexual reproduction,stress response and pathogenicity of Fusarium graminearum.In conclusion,the results of this study on the biological function of MoAuh and FgSsol will expand the study of pathogenicity mechanism in M oryzae and F.graminearum.What's more,our study may provide new targets for pharmaceutical control. |
PDF Full Text Request