Identification and analysis of miRNA - mRNA regulatory modules associated with resistance to bacterial leaf streak in rice

BACKGROUND B: acterial leaf streak (BLS) is a bacterial disease that severely affects rice leaves, leading to significant yield reductions. microRNAs (miRNAs) are short non-coding RNAs extensively involved in the growth, development, and stress responses of plants and animals. However, miRNAs that regulate the response of rice to bacterial leaf streak are still relatively scarce. RESULTS: The indica rice variety Dular exhibits resistance to BLS, whereas the variety 9311 is highly susceptible to the disease. By conducting miRNA sequencing and transcriptome sequencing on both Dular and 9311 before and after BLS inoculation, we identified 19 miRNAs that were significantly downregulated at both 12 and 24 h post-inoculation in Dular, and 9 miRNAs that were significantly upregulated at the same time points in 9311. Additionally, through degradome sequencing, we identified 23 miRNA- mRNA regulatory modules that likely play crucial roles in rice resistance to BLS, and 4 miRNA- mRNA regulatory modules that may be important in rice susceptibility to the disease. DISCUSSION: Current studies on rice disease resistance miRNAs primarily focus on those involved in resistance to rice blast and bacterial blight, with the miRNA-target mRNA regulatory mechanisms for BLS remaining unclear. This study has identified miRNA-mRNA modules that may play significant roles in rice responses to BLS, contributing to the understanding of the miRNA regulatory network involved in rice defense against BLS infection.