Genome-wide identification, functional characterization of protein phosphatase 2A (PP2A) gene family in Cicer arietinum reveals the potential role of CaPP2A-A1 under abiotic stress

Abstract

Drought and salt stress are among the primary abiotic factors that negatively impact crop productivity. To cope with these adverse conditions, plants have evolved various adaptive mechanisms, often mediated by specific genes that confer tolerance to different stresses. In this study, we performed a genome-wide identification of PP2A genes in Cicer arietinum using Arabidopsis thaliana genome as a reference. This study identified 21 CaPP2A members distributed across seven chromosomes. Phylogenetic analysis grouped these genes into six distinct subfamilies, each characterized by unique intron-exon structures and conserved motifs. Promoter analysis revealed the presence of cis-acting elements associated with hormone regulation and abiotic stress responsiveness. RNA sequencing analysis demonstrated that nine PP2A genes were significantly responsive to drought and salt stress which was corroborated by quantitative PCR. Notably, the CaPP2A-A1 gene was identified as a key stress responsive since it exhibited significant upregulation in a stress tolerant cultivar, whereas it was downregulated in a susceptible cultivar under both drought and salt stress conditions, suggesting its pivotal role in stress adaptation. Overall, these findings enhance our understanding of the PP2A gene family in chickpea providing a foundation for future functional studies to unravel the PP2A-mediated regulatory networks governing stress tolerance in C. arietinum and facilitate the development of improved breeding strategies for stress-resilient cultivars.