Figure 1.

The endodermis and its role in lateral root regulation. (A) An Arabidopsis seedling (left) showing magnification of a confocal section of the root tip (right) with the endodermal cell layer highlighted in green and the pericycle, from which lateral roots arise, in blue. The genes, phytohormones and environmental/stress signals currently known to impinge on the endodermis during lateral root development are shown. ABA, abscisic acid; SLs, strigolactones. (B) Confocal section of an Arabidopsis root showing a developing lateral root primordium (arrow) with expression of pAtMYB93::GUS (green) immediately adjacent to the primordium in the overlying endodermal cell (arrowhead). Image courtesy of George Bassel.