Phase separation and biomolecular condensate formation drive plant endomembrane and autophagy crosstalk

Like other eukaryotes, plants are a rich hub of proteins, lipids, and nucleic acid biomolecules that undergo liquid-liquid phase separation to form liquid-like biomolecular condensates that facilitate diverse cellular functions, especially upon biotic and abiotic stresses. Current plant-related research highlights the emerging role of biomolecular condensates in stress sensing, modulation, and response as an intricate mechanism for rapid and efficient stress adaptation. The cellular functions of condensates and their localization emphasize the importance of endomembrane systems in bridging the understanding of membrane-bound and membrane-less organelles and their compartmentalization. This review provides an overview of the recent updates and findings in plant phase separation and biomolecular condensate formation. With the increasing evidence of research pointing to a link between membrane-less condensates, autophagy, and the endomembrane system, we discuss the crosstalk between the multivesicular body (MVB), autophagosome, and vacuole. We also elaborate on the functional and regulatory roles of biomolecular condensates in plant autophagosome formation at the early and late stages. Finally, we provide insights for future investigations on plant cellular biomolecular condensates to pave the way for new frontiers of studies in improving agricultural plant yield, resilience, and other biotechnological applications.