Cytokinin-induced root growth involves actin filament reorganization

Abstract

Root architecture is developmentally plastic and affected by many intrinsic factors (e.g. plant hormones) and extrinsic factors (e.g. touch, gravity) in order to maximize nutrient and water acquisition. We have recently shown that asymmetrical exposure of cytokinin (CK) at the root tip causes root growth directional changes that is dependent on ethylene signaling and is potentiated by glucose signaling. Auxin homeostasis as maintained by auxin signaling and transport is also involved in CK-induced root cell elongation and differential growth. The signaling pathways eventually converge at actin filament organization since actin filament organization inhibitor latrunculin B (Lat B) can also induce similar growth. We, show that CK can actually alter actin filament organization as seen in actin binding protein 35S::GFP-ABD2-GFP transgenic lines as is also altered by auxin polar transport inhibitor 1-N-naphthylphthalamic acid (NPA) and Lat B in different manners.