Protein stability, which is precisely regulated by the ubiquitin-proteasome system (UPS), constitutes a fundamental mechanism in plant physiology under drought stress. While drought signaling cascades are well-studied, the specificity and molecular basis of the UPS-mediated protein degradation remain relatively fragmented. Plants harness ubiquitination-related components, especially E3 ubiquitin ligases, as they are central signal integrators to regulate drought stress responses. These E3 ligases directly modulate the abscisic acid (ABA) cascade pathway and orchestrate crosstalk with mitogen-activated protein kinase (MAPK) and jasmonic acid (JA) signaling, always acting downstream of ABA. Being an integral part of the UPS, the structural stability of the 26S proteasome significantly affects plant responses to dehydration conditions. Furthermore, SUMOylation serves as an additional regulatory layer in shaping plant drought tolerance. The current review summarizes the mechanisms of drought response regulation governed by the UPS and offers perspectives for breeding elite drought-tolerant crop varieties.
Yan et al. (2026) studied this question.