Transcriptional and post-translational regulation of aquaporins in plants.

Abstract

Aquaporins (AQPs) are channel proteins belonging to the major intrinsic protein (MIP) superfamily that mediate the transport of water and other small uncharged molecules across biological membranes. They play essential roles in maintaining cellular homeostasis during plant growth and environmental adaptation. Studies on the molecular regulation of AQP expression and post-translational modification have unveiled an exquisite panorama. The expression of AQP genes is dynamically regulated in response to external and internal signals. Stress- and development-responsive transcription factors (TFs) from AP2/ERF, MYB, NAC, and WRKY families, govern the transcriptional reprogramming in response to drought, salinity stress and/or developmental cues. Besides, post-translational modifications (PTMs), such as residue-specific phosphorylation by kinases (e.g., CPKs, SnRK2s) and ubiquitination by E3 ligases (e.g., AtRma1, OsHIR1), precisely modulate AQP activity and/or stability. This review synthesizes current knowledge on the molecular mechanisms of transcriptional regulation and PTM-driven fine-tuning of AQPs, emphasizing their important roles in optimizing plant growth resilience under fluctuating environmental conditions.