Summary
Plant development relies on the ability of cells to coordinate growth with the cell wall’s biomechanical status. Rapid alkalinization factors (RALFs) and their Catharanthus roseus RLK1-like (CrRLK1L) kinase receptors form a dynamic signaling system linking wall sensing to growth regulation. RALF–CrRLK1L signaling triggers subminute responses, ion fluxes, wall stiffening, and receptor clustering, positioning it as a core regulator of real-time growth modulation. RALFs also act structurally by compacting pectins, introducing a feedback loop between wall composition and signaling. Frequent co-expression and heteromerization of CrRLK1Ls with multiple RALFs argue for a flexible, combinatorial logic rather than simple one-ligand-one-receptor models. This Tansley Insight outlines a conceptual framework in which flexible, modular receptor–ligand networks could underlie dynamic cell wall monitoring.
