Abstract: Arginine methylation is a kind of post-translational modifications existing widely in eukaryotes,of which the main process is to transfer methyl groups provided by S-adenosylmethionine（SAM）to the guanidino group of protein arginine side chain while catalyzed by protein arginine methyltransferases（PRMTs）. Rice blast fungus（Magnaporthe oryzae）infects rice under the suitable conditions,causing severe rice blast and resulting in serious loss of rice yield per year. In recent years,rice blast fungus and rice have already become the ideal model for the study of interaction between plant pathogenic fungi and their host plants. Bioinformatics analysis showed that the rice blast fungus contained four PRMTgenes（MoPRMT1-4）,and PRMTs protein sequence alignment revealed that they contained conservative methyltransferase domains. The PRMTs were demonstrated to be very conservative in filamentous fungi through phylogenetic tree analysis. Extracting the mRNAs of MoPRMT1-4 at various growth and infection stages,we used real time fluorescence quantitative PCR to analyze the expression profiles of the genes,and discovered that the expression of MoPRMT1 reached peak at 24 h post infection,while almost the same at other stages. Compared with other three genes,the expression of MoPRMT2 was low and showed no obvious variation at each stage. MoPRMT3 expressed in high level at germ tube and appressorium developmental stages,while both MoPRMT3 and MoPRMT4 reached peak expressions at mature appressorium stage,and MoPRMT4 also presented peak at 42 h post infection. These data implied that PRMTs genes may play an important regulation role in the pathogenicity of M. oryzae.

Key words: Magnaporthe oryzae, PRMTs, expression analysis