Cell wall remodeling and vesicle trafficking mediate the root clock in Arabidopsis

Signaling for a weakness in cell walls Lateral roots form at regular intervals in the small mustard plantArabidopsis thaliana . Wachsmanet al. have now identified both pectin and subcellular vesicle trafficking as part of the oscillating signaling system that initiates lateral roots. Esterification of pectin regulates its function at the nascent lateral root site, altering the stiffness of cell walls and the strength of cell-cell adhesion. Because lateral root primordia must push through overlying cell layers, reduced cell adhesion at these sites might aid in the formation of lateral roots.Science , this issue p.819