Guanine-nucleotide exchange factor (GEF) that acts as an activator of Rop (Rho of plants) GTPases by promoting the exchange of GDP for GTP. In postembryonic roots, modulates root stem cell maintenance by regulating the expression of PLT1 and PLT2, which are key transcription factors that mediate the patterning of the root stem cell niche. May connect RopGEF-regulated Rac/Rop signaling and auxin-dependent PLT-regulated root pattern formation. Interacts with ARAC1/ROP3, PLT1 and PLT2. Interacts with ARAC1/ROP3 on plasma membrane. During embryogenesis, specifically expressed in the precursor cells of the quiescent center (QC) at the heart, torpedo, bent-cotyledon, and mature embryo stages. At the seedling stage, expressed in the QC and vascular bundles of root differentiated zones and lateral root primordia. Expressed in the vasculature of hypocotyls, and meristemoids and guard cells of cotyledons. By auxin. The PRONE (plant-specific Rop nucleotide exchanger) domain is responsible for the GEF activity. Plants silencing ROPGEF7 show defects in embryo patterning and maintenance of the quiescent center (QC), and postembryonic loss of root stem cell population.