Spatial control of plasma membrane domains: ROP GTPase-based symmetry breaking

Breaking of the cell membrane symmetry to form polarized or localized domains/regions of the plasma membrane (PM) is a fundamental cellular process that occurs in essentially all cellular organisms, and is required for a wide variety of cellular functions/behaviors including cell morphogenesis, cell division and cell differentiation. In plants, the development of localized or polarized PM domains has been linked to a vast array of cellular and developmental processes such as polar cell expansion, asymmetric cell division, cell morphogenesis, the polarization of auxin transporters (and thus auxin polar transport), secondary cell wall patterning, cell type specification, and tissue pattern formation. Rho GTPases from plants (ROPs) are known to be involved in many of these processes. Here, we review the current knowledge on ROP involvement in breaking symmetry and propose that ROP-based self-organizing signaling may provide a common mechanism for the spatial control of PM domains required in various cellular and developmental processes in plants.

► Symmetry breaking to generate distinct domains of the PM is a fundamental cellular process.
► Plant ROP GTPase signaling participates in symmetry breaking to generate polar/local PM domains.
► Tip growth domain generation and maintenance is achieved via ROP positive and negative feedbacks.
► Cortical MTs and ROP generate polar PM domains in cell wall patterning and cell morphogenesis.
► Polar distribution of PINs is modulated by a ROP-based auxin signaling to actin.