Comprehensive Transcriptomic Analysis of the Molecular Mechanisms Conferring Resistance to Rice Blast in the Elite Restorer Line Fuhui2165

Rice blast, caused by <i>Magnaporthe oryzae</i> (<i>M. oryzae</i>), severely threatens global rice production with substantial yield losses, endangering food security and driving demand for resistant varieties. Fuhui2165 (FH2165), an elite restorer line with stable blast resistance, superior agronomic traits, and high grain quality, is valuable for hybrid breeding, but its resistance mechanisms remain unclear. In this study, we investigated the rice blast resistance and underlying mechanisms in FH2165 and its parental lines (Huahangsimiao/HHSM, Minghui86/MH86, and Shuhui527/SH527) using transcriptome sequencing analysis. Phenotypic analysis revealed that FH2165 and HHSM exhibited stronger resistance compared to MH86 and SH527. Differential expression analysis identified 3886, 2513, 3390, and 4678 differentially expressed genes (DEGs) in FH2165, HHSM, MH86, and SH527, respectively. Gene Ontology (GO) enrichment analysis highlighted DEGs associated with chloroplasts, plastids, thylakoids, and related cellular components. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified significant enrichment in pathways such as carbon metabolism, amino acid biosynthesis, and photosynthesis. This suggested that defense strategies could involve energy reprogramming and the synthesis of secondary metabolites. Additionally, the DEGs co-expressed specifically in FH2165 and HHSM were enriched in functions related to RNA processing, GTP binding, and L-ascorbic acid binding, with purine metabolism playing a role in the regulation of energy and signaling. These findings elucidated the critical metabolic and signaling networks that underlie the blast resistance of FH2165 and offered potential targets for breeding high-yield, disease-resistant hybrid rice varieties.