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. During 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 expressed 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 differential 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-fucosidase, and peroxidase, and are involved in the maintenance of cell wall stability, reactive oxygen species 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.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |