Searching for the Virulence-contributing Genes of the Magnaporthe oryzae by Transcriptome Analysis

Magnaporthe oryzae is a fungal pathogen that causes rice blast. Plant metabolites such as plant hormones and phytoalexin can promote or inhibit the rice blast infection. To study the effect of plant metabolites on M. oryzae, we selected salicylic acid (SA), abscisic acid (ABA), and a phytoalexin sakuranetin to treat M. oryzae grown on the medium. Through the analysis of transcriptome data, 185 and 38 genes, 803 and 156 genes, and 1525 and 428 genes were up- or down-regulated after SA, ABA, or sakuranetin treatment. Among these differentially expressed genes (DEGs), most of them were annotated to the cellular process and metabolic process in the biological process category and binding and catalytic activity in the molecular function category by GO analysis. According to KEGG pathway analysis, metabolism is the pathway with the highest number of DEGs, and the main enriched pathway is carbohydrate, lipid, and amino acid metabolism. In addition, we also found two ABA-induced up-regulated genes that may contribute to M. oryzae infection from the transcriptome data. We verified their expressions in M. oryzae that infected rice.