Membrane transport of root-borne trans-zeatin riboside maintains the cytokinin homeostasis in shoots.

ABSTRACT: Ribosylated forms of the plant hormones cytokinins (CKs) are the dominant CK species translocated over long distances. The irreplaceable role of root-to-shoot translocated trans-zeatin riboside in the mediation of shoot development implies the existence of a yet-uncharacterized CK riboside-specific membrane transport system. In this work, we report significant differences in the kinetics of the membrane transport of CK nucleobases and ribosides and the overall affinity of membrane-bound carriers towards the two CK forms. We further characterize the membrane transport of CK nucleobases and ribosides mediated by Arabidopsis EQULIBRATIVE NUCLEOSIDE TRANSPORTER 3 (AtENT3) in tobacco BY-2 cells. Combining experimental data with computational modelling, we show that residues Tyr61 and Asp129, wh

SUBMITTER: Nedved D 

PROVIDER: S-EPMC12675277 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature