Lateral inhibition by a peptide hormone-receptor cascade during Arabidopsis lateral root founder cell formation (Devel. Cell)

The plant hormone auxin acts as a general coordinator of growth and development, transferring information over both long and short ranges. Among other roles, it promotes the formation of the founder cells in roots and it triggers the position of the lateral roots (LR). LR founder cells  are determined in the oscillation zone at the root apex for the LR formation,  but sometimes two pairs are formed in close proximaty yet only one persists. Toyokura et al. describe here how a peptide hormone-receptor cascade plays an essential role in the proper LR spacing. In fact, auxin affects LR spacing by inducing expression of the secreted peptide TOLS2/PIPL3 in the LR founder cells, which negatively regulates LR initiation through a lateral inhibition mechanism controlled by the signalling cascade TOLS2-RLK-PUCHI in a non-cell autonomous manner. (Summary by Francesca Resentini) Devel. Cell 10.1016/j.devcel.2018.11.031