Genome-wide identification of the PR-1 gene family and functional analysis of MsPR-1-12 under drought stress in alfalfa (Medicago sativa L.)

Alfalfa (Medicago sativa L.), a vital leguminous forage crop, faces growth and distribution constraints due to abiotic stresses, such as drought. Pathogenesis-related protein 1 (PR-1) is a major class of plant defense proteins involved in responses to environmental stress. However, the distribution and functional roles of the PR-1 gene family in alfalfa under drought stress remain largely unexplored. Nineteen MsPR-1 genes were identified in the alfalfa genome through systematic screening, with phylogenetic clustering dividing these genes into three evolutionarily distinct clades. Expression profiling highlighted MsPR-1-12 as a candidate gene for drought tolerance. Subcellular localization indicated that MsPR-1-12 is localized to the nucleus membranes and cellular membranes. Furthermore, reverse transcription and quantitative PCR(RT-qPCR) analysis demonstrated a significant upregulation of MsPR-1-12 under drought stress. Heterologous expression of MsPR-1-12 in yeast conferred enhanced drought resistance. These findings provide novel insights into the MsPR-1 gene family in alfalfa and offer valuable genetic resources for the development of drought-tolerant alfalfa varieties through genetic engineering.