Go with the flow: ABCC4 mediates cytokinin efflux to control root development

The plant hormone cytokinin controls many developmental processes in plants, ranging from shoot apical establishment, flower development, leaf cell proliferation, root vascular development, lateral root initiation, and root meristem size Specifically in root tips, cytokinin plays an important role in establishing the meristem size by defining the proximal end of the meristem. For instance, cytokinin signaling induces the onset of the endocycle, a cell cycle where DNA replication is repeated several times without cytokinesis that is associated with cell differentiation and establishing the transition domain On the other hand, cytokinin acts as a negative regulator of polar auxin transport and promotes auxin degradation in that specific zone (Di Mambro et al.,