小麦干热风胁迫下相关miRNA的筛选及其靶基因分析OA

To elucidate the molecular mechanism of miRNA in wheat's response to dry-hot wind stress,a sensitive germplasm Xinchun 14 and a tolerant variety Xinchun 46 were selected as materials.Dur-ing the grain-filling stage,artificial simulation of dry-hot wind stress(daytime temperature 35 ℃/nighttime temperature 25 ℃,relative humidity 20％,wind speed 5 m·s-1,continuous treatment for 5 days)was applied.High-throughput sequencing technology was used to screen differentially ex-pressed miRNAs,followed by validation via qRT-PCR.The results showed that 203 miRNAs were involved in the expression under dry-hot wind stress,with 136 co-expressed miRNAs.After differen-tial screening,six core differentially expressed miRNAs were ultimately identified,namely,novel_miR_537,novel_miR_443,novel_miR_469,novel_miR_393,novel_miR_390,and novel_miR_339.These miRNAs were significantly enriched in four pathways:the biosynthesis of mannose O-glycans,the degradation of polysaccharides,peroxisomes,and the metabolism of selenium compounds.Target gene predictions revealed that these miRNAs targeted and regulated key membrane protein-encoding genes,including β-1,2-xyltransferase,α-1,3-arabinosyltransferase,GDSL esterase/lipase,α-L-fucosi-dase,and peroxidase,and are involved in the maintenance of cell wall stability,reactive oxygen spe-cies clearance,and osmotic regulation processes.This indicates there is a miRNA regulatory network in the response of dry-hot wind in wheat,and it jointly participates in the resistance process of wheat to dry-hot wind stress in the form of a'miRNA-targeted gene'molecular module.