Fig. 7
From: Asymmetric distribution of cytokinins determines root hydrotropism in Arabidopsis thaliana
A current model explaining how root hydrotropism is achieved. When roots are growing in an environment with unequal water potential, cytokinins are accumulated at the lower water potential side, up-regulating the expression of ARRs such as ARR16 and ARR17, causing more cell division at the lower water potential side of the root tip. As a consequence, the root tip bends towards the higher water potential side of the root. MIZ1 is required for the formation of cytokinin asymmetric distribution and the expression levels of ARRs
