Abstract:Rice blast causes serious damage to rice growth and great economic losses in rice production yearly. Compared to the wild type plants, OsDCL1-RNAi knock-down mutant plants showed enhanced resistance to rice blast. To investigate the resistant mechanism of the mutant to rice blast, we analyzed and compared the transcriptome profiling in the wild type and OsDCL1-RNAi mutant plants upon challenge with the rice blast pathogen. Out of 7 129 differentially expressed genes (DEGs) responsive to the infection of rice blast pathogen, 5 382 and 5 180 were identified in NPB and OsDCL1-RNAi mutant, respectively. The genes involved in 4 pathway groups including biotic stress response, signaling, protein metabolism, and RNA regulation were significantly identified in the DEGs. Moreover, we identified 1 318 DEGs in OsDCL1-RNAi mutant compared to the wild type plants without pathogen infection. Of those DEGs in OsDCL1-RNAi mutant plants, 70% were up-regulated and most of them were involved in two pathway groups, i.e., biotic stress response and signaling. Interestingly, the genes encoding various families of pathogenesis related (PR) and cell wall related proteins were frequently identified in biotic stress response genes. We also identified 10 jasmonic acid and 11 salicylic acid related genes that were down- and up- regulated in OsDCL1-RNAi mutant plants, respectively. The genes encoding transcription factors, e.g., WRKY and MYB families, and some receptor kinases were also abundantly identified in OsDCL1-RNAi mutant plants. Some differentially expressed genes were selected for qRT-PCR validation, the result is consistent with the DEGs. The altered transcriptome profiling of OsDCL1-RNAi mutant plants documented in this study could provide new insights into the enhanced resistance mediated by the silencing of OsDCL1 in rice.