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

Abstract

Abiotic and biotic stresses constitute substantial challenges to global agricultural productivity. Plants have evolved complex regulatory mechanisms to mitigate these stresses, including signaling networks that govern physiological, biochemical, and molecular responses. Among these, protein phosphorylation plays a pivotal role in stress adaptation; protein phosphatase 2C (PP2C) proteins serve as key regulators across multiple signaling pathways. PP2Cs influence plant stress responses through interactions with various proteins, including SNF1-RELATED PROTEIN KINASE 2s (SnRK2s), abscisic acid (ABA) receptors, transcription factors, and ion channels, thereby fine-tuning signaling cascades and physiological adaptations under stress conditions. This review provides a comprehensive analysis of the PP2C gene family in plants, emphasizing their structural characteristics, regulatory mechanisms, and functional roles in abiotic and biotic stress responses. We highlight the biological significance of PP2Cs in modulating critical pathways such as ABA, mitogen-activated protein kinase (MAPK), and calcium signaling. Additionally, we explore the roles of PP2Cs in regulating root development, stomatal behavior, ion homeostasis, and immune responses, demonstrating their roles in coordinating plant developmental processes with adaptive responses to environmental challenges, particularly under resource-limited conditions. Finally, we identify current knowledge gaps and propose future research directions to advance the broader understanding of PP2C-mediated regulation of physiological functions, stress responses, and developmental signaling. Deeper insights into PP2C functions may facilitate novel strategies to promote crop resilience and enhance agricultural sustainability.