The epidermal pavement cell shape in Arabidopsis is driven by chemical and mechanical cues that direct partitioning mechanisms required for the establishment of the lobe- and indentation-defining polar sites. Brassinosteroid hormones promote pavement cell morphogenesis, but the underlying mechanism remains unclear. We used combination of proteomics, forward genetics, and visualization techniques to connect brassinosteroid and ROP2-GTPase signalling pathways via the regulation of RopGAPs and put forward the importance of spatiotemporal control of brassinosteroid signalling for pavement cell interdigitation