| Hot-dry wind is a major meteorological disaster threatening wheat production in Northwest China, often causing premature senescence during grain filling, impaired grain development, and significant yield loss. MicroRNAs (miRNAs) are non-coding small RNAs with regulatory functions in plants and can respond to abiotic stresses to regulate plant growth and development. However, the molecular mechanisms of miRNAs in wheat tolerance to hot-dry wind stress remain largely unexplored. This study used wheat cultivars Xinchun 14 (sensitive to hot-dry wind) and Xinchun 46 (tolerant to hot-dry wind) as materials. Artificial hot-dry wind stress was applied during the grain-filling stage (daytime 35°C/night 25°C, relative humidity 20%, wind speed 8 m/s, continuous treatment for 5 days). High-throughput sequencing was combined with qRT-PCR to identify differentially expressed miRNAs. A total of 203 miRNAs were involved in the response to hot-dry wind stress, with 136 co-expressed miRNAs. Under strict thresholds (FDR ≤ 0.01, |log2FC| ≥ 1), six core differentially expressed miRNAs (novel_miR_537, novel_miR_443, novel_miR_469, novel_miR_393, novel_miR_390, novel_miR_339) were identified. These miRNAs were significantly enriched in pathways such as manose-type O-glycan biosynthesis, polysaccharide degradation, peroxisome, and selenium compound metabolism. Target gene prediction revealed that these miRNAs regulate key genes such as β-1,2-xylosyltransferase, α-1,3-arabinosyltransferase, GDSL esterase/lipase, α-L-fucosidase, and peroxisomal membrane protein, involved in cell wall stability, reactive oxygen species scavenging, and osmotic regulation. This study provides the first systematic elucidation of the miRNA regulatory network in wheat under hot-dry wind stress, offering molecular targets for the development of new stress-tolerant germplasm. |
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