Transcriptomic analysis of different alfalfa varieties under saline-alkali stress.
Alfalfa, a globally important leguminous forage crop, is valued for high yield, superior nutritional quality, and robust stress resistance. It is widely used in animal husbandry and ecological protection. However, soil salinization has become a major environmental factor limiting its yield and quality. In this study, two alfalfa cultivars, Zhongmu No.1 (ZM) and SK3010 (SK), were subjected to saline-alkali stress. Compared with SK, ZM exhibited less damage and stronger saline-alkali tolerance. Transcriptomic analysis revealed that the proportion of up-regulated differentially expressed mRNAs (DEMs) in ZM was significantly higher than in SK. The antioxidant systems and plant hormone signal transduction pathways are central to saline-alkali stress adaptation. Integrated transcriptome and small RNA sequencing indicated that alfalfa mitigates saline-alkali stress through the regulation of antioxidant system, hormone biosynthesis and signaling, phenylpropanoid biosynthesis, and the hydrolysis of starch to soluble sugars.This provides a new direction for the breeding of saline-alkali tolerant alfalfa varieties.