Regulation of the transporters required for the correct auxin pattern.

(A–D) The ‘DR5-like’ output of (A) static simulations with unregulated PIN expression in (B) wild type; (C) wol; or (D) cytokinin-treated roots. (E–G) The ‘DR5-like’ output of (E) ‘dynamic’ simulations, in which the PINs are regulated, in (F) wild type; (G) wol; or (H) cytokinin-treated roots. (I–K) The pattern of the auxin signalling reporter IAA2::GUS in (I) wild type; (J) wol; and (K) cytokinin-treated roots. Scale bars in cross sections represent 10μm. In the schematics, yellow arrows represent PIN transporters, pink arrows represent auxin influx via diffusive permeability, and red arrows represent an auxin influx transporter.