| Rice（Oryza sativa）is one of the most important crops in the world.The hemibiotrophic filamentous ascomycete Pyricularia oryzae syn.Magnaporthe oryzae caused rice blast,threatened global food security seriously.To date,using chemical fungicides and utilizing resistant cultivars are the primary control strategies.But the perennial use of a single chemical agent will not only cause environmental pollution but also lead to the emergence of drug-resistant populations,which will cause the chemical agents to lose their utility value.Meanwhile,due to the high variation of the rice blast pathogen,resistant cultivars will lose resistance against M oryzae in a few years after their initial deployment in the field.So presenting efficient control strategies were crucial for stabilized production of rice.Hence,elaborating the molecular mechanism under the pathogenicity of M.oryzae is urgent which will support new ideas for resistant breeding,and provide new candidate targets for developing novel fungicides.In this study,we mainly analyzed the biological function of endoplasmic reticulum associated degradation（ERAD）related genes MoHRD1 and MoDER1 during the vegetative growth and pathogenesis development of M.oryae.And the main results are as followed.Previous studies have showed that unfolded protein response（UPR）plays an essential role in vegetative growth and pathogenesis development of M.oryzae.Endoplasmic reticulum（ER）membrane-anchored protein MoIre 1 and bZIP transcription factor MoHac1 regulate the ER stress and involve in control the growth,asexual reproduction,and pathogenesis of M.oryzae.In this study,we reported the identification and characterization of the ubiquitin ligase MoHrdl and the ER transmembrane protein MoDer1.MoHrd1 encoded by MGG09205,an orthologous protein of Hrd1 in Saccharomyces cerevisiae.The MoHrd1 protein contains a conserved RING domain and the MoDerl protein contains a DER1 domain,both MoHrdl and MoDerl were ERAD signaling pathway associated proteins.Real-time PCR results showed that MoHRD1 and MoDER1 were significantly upregulated during asexual development and host infection stages.Both MoHrdl and MoDerl were localized to the ER.In order to further study the functions of these two genes,we obtained the MoHRD1 and MoDER1 single deletion mutant △Mohrd1,△Moder1,and the double deletion mutant △Mohrd1△Moder1,respectively,via gene knock-out.Compared with the wild type strain Guyll,pathogenicity of the deletion mutant△Mohrd1 reduced obviously.However,pathogenicity of the deletion mutant △Moder1 was not impaired.In terms of asexual development,double deletion mutant △Mohrd1△Moder1 were apparently impaired,pathogenicity of this mutant was losed either.Further investigation showed that MoHRD1 synthesize with MoDER1 to regulate ER stress response,conidium morphogenesis,appressorium formation,melanin biosynthesis,UPR pathway and secretory pathway.Meanwhile,IP-MS,RNA-seq results showed that MoHrdl and MoDerl involved in control the secretory pathway and cellular metabolism.In summary,the ERAD signaling pathway plays an important role in the development of M.oryzae.The ERAD associated genes,MoHrdl and MoDerl,regulate the ERAD and are necessary for the growth,asexual reproduction and pathogenesis development of M.oryzae. |
