Proteomics Analysis Of Rice Response To Magnaporthe Oryzae And Osglo1 Mediates Disease Resistance Against Rice Blast

Rice blast disease caused by Magnoporthe oryzae is the most serious disease in many rice-growing regions of the world.Based on the significant economic importance,investigating and understanding the interaction mechanism between rice and M.oryzae means a lot.According to the gene-for-gene hypothesis,the defense responses are often activated by the action of a host resistance gene(R)and a pathogen avirulence gene(Avr).Therefore,we are interested in identifying rice resistance genes in rice defense process.Meanwhile,in the post-genomic era,proteomics begins to play vital roles.As proteins are directly related to functions,more and more proteomic technology are used for finding resistance proteins.In this study,we used two high-throughput proteomic technology,iTRAQ and dimethyl labeling,to analyze the rice proteins after infection by M.oryzae,and focused on potential rice resistance-related genes,such as OsGLO1.Besides,we validated the functions of OsGLOl through rice protoplast transformation system,and found that OsGLO1 can mediate disease resistance against rice blast.Proteomics analysis of rice response to M.oryzae:To investigate the protein profiles during the process of rice response to rice blast and relevant biological processes,in this study,both a compatible strain(Guy11)and an incompatible strain(2539)were used to infect Oryza sativa L.japonica.cv.Nipponbare,and then collected protein samples at two time points:Oh,96h.By combining iTRAQ and stable isotope dimethyl(dimethyl labeling),we tried to identify proteins involved in rice innate immunity against M.oryzae infection.From the results of iTRAQ,200 proteins were identified as up-regulated proteins(cut-off≥1.5)and 114 proteins were identified as down-regulated proteins(cut off≤0.67)in both compatible and incompatible infections.Besides,19 proteins were identified as Guyll-induced proteins(Guy11≥1.5 AND 2539<1.5),and 14 proteins were identified as Guyl 1-supressed proteins(Guy11≤0.67 AND 2539>0.67).To validate the above results,the same set of samples were examined by dimethyl labeling and we found that nearly 1/3 of proteins were identified and 54.5%of proteins present similar expression profiles.These proteins are involved in metabolic,oxidation-reduction,response to stimulus,and biological regulation.In all,through two high-throughput protein analysis and bioinformatics information,we narrowed down to individual protein,such as OsGLO,which would help us further understand the mechanism of interaction between rice and M.oryzae.OsGLO1 mediates disease resistance against rice blast:Glycolate-oxidase(GLO)mediating H2O2 formation is one of the two processes producing H2O2 during photosynthesis.It has been reported that GLO mediating H2O2 production is associated with abiotic stresses such as drought and salt.Here we showed that OsGLO1 is also involved in resistance against biotic stress.OsGLO1 is specifically suppressed by the infection of a compatible,but not an incompatible,M.oryzae strain.The expression of OsGLO1 is positively correlated with H2O2 accumulation and callose deposition in vivo,and resistance related genes such as OsPBZl,OsPAD4,and OsAOS2.Our results indicate that OsGLO1 is suppressed after Guy11 infection and plays a vital role during the process against rice blast.