Maturation of the Ground Tissue of the Root Is Regulated by Gibberellin and <i>SCARECROW</i> and Requires <i>SHORT-ROOT</i>

As the root of Arabidopsis ( Arabidopsis thaliana ) ages, a third layer of ground tissue forms that we find rapidly takes on cortex character. We show that GA and SCARECROW ( SCR ) regulate the timing of this developmental transition and that SHORT-ROOT ( SHR ) is required for it. The Arabidopsis