Inducible depletion of PI(4,5)P2 by the synthetic iDePP system in Arabidopsis

International audiencePI(4,5)P-2 is importantly involved in a broad array of cellular processes, including polar auxin transport, vesicle trafficking and anisotropic cell growth. An inducible system is developed in Arabidopsis to conduct tunable depletion of PI(4,5)P-2 and reveal new roles of this membrane lipid.Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P-2) is a low-abundance membrane lipid essential for plasma membrane function(1,2). In plants, mutations in phosphatidylinositol 4-phosphate (PI4P) 5-kinases (PIP5K) suggest that PI(4,5)P-2 production is involved in development, immunity and reproduction(3-5). However, phospholipid synthesis is highly intricate(6). It is thus likely that steady-state depletion of PI(4,5)P-2 triggers confounding indirect effects. Furthermore, inducible tools available in plants allow PI(4,5)P-2 to increase(7-9) but not decrease, and no PIP5K inhibitors are available. Here, we introduce iDePP (inducible depletion of PI(4,5)P-2 in plants), a system for the inducible and tunable depletion of PI(4,5)P-2 in plants in less than three hours. Using this strategy, we confirm that PI(4,5)P-2 is critical for various aspects of plant development, including root growth, root-hair elongation and organ initiation. We show that PI(4,5)P-2 is required to recruit various endocytic proteins, including AP2-mu, to the plasma membrane, and thus to regulate clathrin-mediated endocytosis. Finally, we find that inducible PI(4,5)P-2 perturbation impacts the dynamics of the actin cytoskeleton as well as microtubule anisotropy. Together, we propose that iDePP is a simple and efficient genetic tool to test the importance of PI(4,5)P-2 in given cellular or developmental responses, and also to evaluate the importance of this lipid in protein localization