Figure 1.

Vascular patterning in Arabidopsis shoot inflorescence stem. (A) Radial section of DR5::GUS expression at the base of the inflorescence stem in Arabidopsis Col-0 plants. (B) Computer simulation result for auxin concentration ([Auxin]) in arbitrary units (a.u.) along a ring of cells; x and y stand for spatial coordinates. Auxin is distributed in maxima which, according to the model hypothesis, position vascular bundles. (C) Longitudinal section of Arabidopsis Col-0 wild-type plant at the most apical zone, immediately below the shoot apical meristem. Arrows point to xylem strains coming from the lateral organs.