Genome-wide identification of the pea protein Phosphatase 2C (PP2C) family and expression patterns during abiotic...

Protein phosphatase 2C (PP2C), a member of the largest family of phosphatases in plants, plays a crucial role in regulating stress response, growth and development, and hormone signaling. The pea (Pisum sativum) is globally cultivated legume crop of significant for both food and forage. In agricultural production, abiotic stresses such as drought, soil salinity, and extreme temperature severely limit pea yield. Although the PP2C gene family is known to be critically involved in growth regulation and abiotic stress response, no systematic studies on this gene family in peas have been reported to date.

In this study, 93 pea PP2C genes were identified on a genome-wide level and designated PsPP2C1 through PsPP2C93 according to their chromosomal locations. The 93 PsPP2C proteins were analyzed for parameters including amino acid sequence length, molecular weight, isoelectric point, predicted subcellular localization, exon number, and hydrophilicity. The pea PP2C gene family was divided into 13 subfamilies (A-L) and four tandem duplication and 23 segmental duplication events were identified. The expression levels of 20 selected PsPP2C genes were investigated under four types of abiotic stress and across different seed development stages. PsPP2C15 exhibited strong upregulation under all four stress conditions, with expression increasing more than 13-fold under cold stress. In contrast, expression of PsPP2C1 and PsPP2C58 was suppressed across all stress treatments. During seed development, PsPP2C7 showed notably high expression, while PsPP2C15 was highly expressed in 21-day-old leaves. Subcellular localization predictions indicated that PsPP2C15 is likely chloroplast-localized. Promoter analysis revealed an enrichment of cis-acting elements associated with photosynthesis and hormone regulation, suggesting that PsPP2C15 may play an important role in both developmental processes and abiotic stress responses in pea. This study presents the first genome-wide identification and characterization of the PP2C gene family in pea, comprising 93 members. The expression patterns of 20 PsPP2C genes were analyzed by quantitative real-time PCR (qRT-PCR), under abiotic stresses and during seed development, providing insights into their potential biological functions. Those findings suggest that the PP2C family is important for pea growth and development, with PsPP2C15 emerging as a key candidate for further investigation in abiotic stress tolerance and seed development.