Comparative transcriptomic analysis reveals coordinated mechanisms of different genotypes of common vetch root in response to Al stress

Due to its exceptional resistance to abiotic stress, common vetch (Vicia sativa L.) is widely cultivated as an alternative methane source and a potentially healthy food and feed option. However, the comprehensive molecular processes behind various cultivars of common vetch's response to Al stress remain largely unexplored. In this study, a total of 35,969 unigenes, with an average length of 1302.79 bp and an N50 length of 2109 bp, were identified. Among these, 1965 and 6684 differentially expressed genes (DEGs) were detected in the Al-sensitive (Lanjian No.2) and Al-tolerant (Lanjian No.3) cultivars, respectively, with 331 DEGs commonly expressed in both cultivars. KEGG enrichment analysis revealed substantial enrichment of the citrate cycle (TCA cycle) and plant hormone signal transduction in Lanjian No.3, whereas "Plant-pathogen interaction" was significantly enriched in Lanjian No.2. Moreover, Al toxicity is suggested to be regulated through sodium-potassium channels, demethylation and esterification of cell wall pectin, as well as Ca2+-mediated CBL-CIPK signaling, hormone signaling, and TF binding. The candidate genes discovered in this study could be useful for breeding Al-tolerant pea cultivars in locations with acidic soil and may also reveal new insights into the molecular mechanism of Al stress in legumes. •MDH-mediated malate synthesis and secretion play an important role in Al tolerance in common vetch.•CBL-CIPK signal transduction confers Al ion detoxification ability in common vetch.•Al stress alters phytohormone signal transduction and inhibits common vetch root tip growth.