Salt stress-related function of the oil body-associated protein gene LcOBAP2B in Leymus chinensis

Oil bodies are dynamic organelles in plant seeds. Oil body-associated protein (OBAP) is involved in regulating the size and vitality of oil bodies in overwintering seeds, and affects lipid mobilization and stress resistance during seed germination. In this study, we cloned an oil body associated protein gene LcOBAP2B (Leymus chinensis oil body associated protein 2B). The LcOBAP2B coding sequence is 753 bp long, encoding a 250-amino acid protein. Expression analysis showed that LcOBAP2B was predominantly expressed in seeds, with lower levels in leaves and roots. Under salt stress, the expression of the gene was upregulated in both seeds and leaves, with the level of upregulation being higher in salt-tolerant germplasm compared to salt-sensitive germplasm in Leymus chinensis. Transgenic Arabidopsis expressing LcOBAP2B showed significantly improved salt resistance. Transgenic lines exhibited enhanced salt resistance, characterized by increased green cotyledon numbers, root length, plant biomass, and survival rates compared to wild type plants under salt stress conditions. These findings suggest that LcOBAP2B may play a role in resistance to salt stress in Leymus chinensis.