Characterization of the BPC Genes in Alfalfa and Functional Verification of MsBPC10 in Salt Tolerance

This study systematically analyzed the BPC family in alfalfa (Medicago sativa) for the first time, identifying 18 MsBPC genes randomly distributed on 14 chromosomes. Their encoded proteins are mostly alkaline and classified into three subgroups. Cis-acting element analysis of promoters showed that the promoter region of MsBPC contains various cis-acting elements related to hormone response, growth and development, as well as stress response. Expression pattern analysis in different tissues revealed that 7 were expressed in all 6 tissues, 4 were only expressed in a single tissue, and the remaining genes were expressed in 3-5 tissues, suggesting that MsBPC genes may be involved in the regulation of different growth and developmental stages of Medicago sativa. Transcriptome analysis under salt, drought, and cold stresses showed that 12, 11, and 12 genes responded, respectively. RT-qPCR detection confirmed that MsBPC genes responded to salt and drought treatments, further verifying their important roles in abiotic stress responses Subcellular localization analysis revealed that MsBPC5 and MsBPC10 are localized in the nucleus, which is consistent with the predicted results. heterologous expression in yeast was employed to characterize the function of MsBPC10, which was upregulated in response to salt stress. The study conducted a comprehensive identification and analysis of the BPC gene family in Medicago sativa. Through the analysis of RNA-seq data, candidate genes related to abiotic stress were screened out, providing candidate genes for Medicago sativa stress-resistant breeding.