MicroRNAs associated with spot blotch in bread wheat (Triticum aestivum)

Abstract

Spot blotch, caused by the fungal pathogen Bipolaris sorokiniana, poses a significant threat to wheat production worldwide, particularly in warm and humid regions. Recent advances in molecular biology have highlighted the pivotal role of microRNAs (miRNAs) in regulating plant defense responses against various biotic stresses, including fungal infections. In the present study, miRNAs in wheat were examined during spot blotch infection. High-throughput sequencing and bioinformatics analysis were employed to identify differentially expressed miRNAs in resistant and susceptible wheat genotypes (YS#54 and YS#83) following B. sorokiniana inoculation. As many as 572 conserved and 632 additional miRNAs (potentially novel) were identified; some of them were upregulated and others downregulated, suggesting their involvement in defense signaling pathways, including those targeting transcription factors and resistance-related genes. Targets for miRNAs were also identified for 467 miRNAs, which included 7937 transcripts; the expression profiles of transcripts generally had a negative correlation with miRNA expression. The results of the present study provide new insights into the miRNA-mediated regulatory networks in wheat-pathogen interactions and lay the groundwork for the development of miRNA-based markers or strategies for enhancing resistance to spot blotch disease. © 2025 Elsevier Ltd