To identify the SWEET genes in Avena sativa and its responses to drought and salinity-alkalinity stress， this study systematically characterized the AsSWEET gene family using bioinformatics approaches and analyzed their expression patterns under drought and salt-alkali stress conditions by RT-qPCR. A total of 37 AsSWEET genes were identified and mapped to 19 chromosomes. All AsSWEET proteins contained the conserved MtN3_saliva domain， most members possessed seven transmembrane helices （TMHs）， and subcellular localization prediction indicated that they were primarily located on the plasma membrane. Phylogenetic analysis revealed that AsSWEET proteins could be classified into four major clades and shared high homology with SWEET proteins from Hordeum vulgare. Promoter analysis showed that AsSWEET family members harbored numerous cis-acting elements associated with light responsiveness， hormone signaling， development， and abiotic stress responses. Expression profiling indicated that 10， 7 and 18 AsSWEETs genes were significantly upregulated in leaves under drought， salt and alkali stress， respectively. Among them， AsSWEET15a and AsSWEET15c exhibited consistently high expression levels across all stress conditions， suggesting that they might serve as key candidate genes involved in oat tolerance to drought and salt-alkali stress. These findings provide theoretical insights into the functional roles of the AsSWEET gene family in abiotic stress responses and offer potential gene resources for molecular breeding of stress-tolerant oat varieties.

Avena sativa  /  SWEET proteins  /  Bioinformatics  /  Abiotic stress  /  Gene expression