The multifaceted roles of PP2C phosphatases in plant growth, signaling, and response to abiotic and biotic stress.

Abiotic and biotic stresses pose significant challenges to global agricultural productivity. Plants have developed complex regulatory mechanisms to mitigate these stresses, involving signaling networks that mediate physiological, biochemical, and molecular responses. Among these mechanisms, protein phosphorylation plays a crucial role in plant stress adaptation, with protein phosphatase 2C (PP2C) proteins acting as key regulators in various signaling pathways. PP2Cs modulate plant stress responses through interactions with a range of proteins, including SnRK2 kinases, ABA receptors, transcription factors, and ion channels, allowing them to fine-tune signaling pathways and physiological responses under stress conditions. This review provides a comprehensive analysis of the PP2C gene family in plants, focusing on their characteristics, regulatory mechanisms, and functional roles in abiotic and biotic stress responses. We highlight the biological significance of PP2Cs, and their involvement in modulating key pathways, including abscisic acid (ABA), MAP kinase (MAPK), and calcium signaling. Furthermore, we discuss the role of PP2Cs in controlling root development, stomatal regulation, ion homeostasis, and immune responses, highlighting their roles in coordinating plant developmental programs with adaptive mechanisms activated during stress conditions, particularly under limited resources. We also identified key research gaps and outlined future directions that could enhance our understanding of PP2Cs' regulatory roles in physiological processes, stress responses, and developmental signaling pathways. Gaining deeper insights into PP2C-mediated functions may open new opportunities for advancing agricultural sustainability.