Tissue-specific expression and genome-wide analysis of RALF gene family in pea (Pisum sativum L.) under different stresses

The rapid alkalinization factor (RALF) gene family plays a crucial role in plant growth, development, and stress responses, yet its characterization in pea (Pisum sativum L.), an agronomically important legume, remains limited. This study identified eight PsRALF genes in the pea genome, phylogenetically clustered into 8 distinct groups, and analyzed their structural features, evolutionary relationships, and expression patterns under various abiotic stresses. Chromosomal localization and collinearity analyses revealed both conserved and lineage-specific duplication events, while promoter analysis identified stress- and hormone-responsive cis-elements, suggesting their roles in stress adaptation. Under abiotic stress conditions such as drought, salinity, and aluminum toxicity, PsRALF2 exhibits significant upregulation, highlighting the potential of this gene as a stress-responsive candidate. Subcellular localization predictions indicate that members of this family are predominantly localized extracellularly, with one member targeted to the chloroplast, suggesting that they may possess diverse functional roles. Additionally, All analyzed PsRALFs possesed prion-like domain (PrD) features with varying prominence, suggesting their potential to drive protein aggregation or liquid-liquid phase separation (LLPS) that may mechanistically regulate signaling functions. These findings provide foundational insights into the PsRALF family, offering valuable targets for breeding climate-resilient pea varieties to enhance sustainable agriculture and meet the growing demand for plant-based proteins.