biostudies-literatureUnknown111(19)Ko DCytokinins are phytohormones that induce cytokinesis and are essential for diverse developmental and physiological processes in plants. Cytokinins of the trans-zeatin type are mainly synthesized in root vasculature and transported to the shoot, where they regulate shoot growth. However, the mechanism of long-distance transport of cytokinin was hitherto unknown. Here, we report that the Arabidopsis ATP-binding cassette (ABC) transporter subfamily G14 (AtABCG14) is mainly expressed in roots and plays a major role in delivering cytokinins to the shoot. Loss of AtABCG14 expression resulted in severe shoot growth retardation, which was rescued by exogenous trans-zeatin application. Cytokinin content was decreased in the shoots of atabcg14 plants and increased in the roots, with consistent changProceedings of the National Academy of Sciences of the United States of America7150-5https://www.ebi.ac.uk/biostudies/studies/S-EPMC4024864biostudies-literatureArabidopsis ABCG14 is essential for the root-to-shoot translocation of cytokinin.PMC4024864Kiba TSong WYMartinoia EPark JKwon MKim KYKo DSakakibara HKojima MDo JEndler ALee YKang JfalseArabidopsis ABCG14 is essential for the root-to-shoot translocation of cytokinin.Cytokinins are phytohormones that induce cytokinesis and are essential for diverse developmental and physiological processes in plants. Cytokinins of the trans-zeatin type are mainly synthesized in root vasculature and transported to the shoot, where they regulate shoot growth. However, the mechanism of long-distance transport of cytokinin was hitherto unknown. Here, we report that the Arabidopsis ATP-binding cassette (ABC) transporter subfamily G14 (AtABCG14) is mainly expressed in roots and plays a major role in delivering cytokinins to the shoot. Loss of AtABCG14 expression resulted in severe shoot growth retardation, which was rescued by exogenous trans-zeatin application. Cytokinin content was decreased in the shoots of atabcg14 plants and increased in the roots, with consistent chang2014-01-01T00:00:00Z2014 May2025-04-05T13:37:34.241Z2019-03-27T01:28:26ZS-EPMC40248642477825710.1073/pnas.1321519111