Transcriptomic and metabolomic analyses on the Piz-t-mediated resistance in rice against Magnaporthe oryzae

Magnaporthe oryzae causes devastating rice blast disease, significantly impacting rice production in many countries. While various practices have been employed to minimize the damage caused by rice blast, genetic resistance is considered the most economical and effective strategy for controlling the disease. Among the many known resistance (R) genes, Piz-t confers broad-spectrum resistance to M. oryzae isolates and encodes a nucleotide-binding site leucine-rich repeat receptor (NLR). Although Piz-t-interacting proteins and those in the signal transduction pathway have been identified over the last decade, the Piz-t-mediated resistance has not been fully understood at the transcriptomic and metabolomic levels. In this study, we performed transcriptomic and metabolomic analyses in the Piz-t plants after inoculation with M. oryzae. The transcriptomic analysis identified a total of 15,571 differentially expressed genes (DEGs) between Piz-t and wild-type plants, with 2,791 specifically induced in the Piz-t plants. K-means clustering, GO analysis, and KEGG enrichment pathway analyses of the total DEGs identified five groups of DEGs with distinct gene expression patterns at different time points post-inoculation. The gene expression patterns in the transcriptomic datasets were well correlated with the metabolomic profiling. Broad-spectrum metabolomic analyses indicated that terpenoid, phenylpropanoid, flavonoid, fatty acid, amino acid, glycolysis/TCA, and phenylalanine pathways were altered in the M. oryzae-infected plants. This study offers new insights into the molecular dynamics of transcripts and metabolites in R-gene-mediated resistance against M. oryzae and provides candidates for enhancing rice blast resistance through the engineering of metabolic pathways.