Biomolecular Condensates in Combined and Recurrent Plant Stresses: Integrating Phase Separation, Signal Prioritization, and Cross-Stress Memory

Plants frequently encounter overlapping, sequential, and recurrent stresses, but the cellular mechanisms that organize responses to these complex conditions remain incompletely understood. Biomolecular condensates are membrane-less assemblies formed through phase separation and multivalent molecular interactions, and they can regulate RNA metabolism, protein sequestration, signaling specificity, transcriptional control, and stress recovery. This review evaluates the hypothesis that plant condensates may contribute to the organization of combined and recurrent stress responses by modulating molecular accessibility, transcript fate, proteostasis, and regulatory crosstalk. We synthesize current knowledge on stress granules, processing bodies, nuclear condensates, plastid-associated condensate-like assemblies, and other stress-responsive compartments, with emphasis on their possible roles in signal filtering, RNA triage, and recovery-associated reprogramming. We also distinguish established evidence from emerging hypotheses, particularly regarding condensate-mediated signal prioritization and stress memory. Current data support condensates as rapid stress-responsive organizers, but direct evidence for their persistence after recovery or their causal roles under simultaneous multi-stress conditions remains limited. By integrating phase separation biology with plant multi-stress physiology, this review proposes a testable conceptual framework and identifies methodological priorities for future studies in plant stress resilience and crop improvement.