Cytokinins are a class of phytohormones, signalling molecules specific to plants. They act as regulators of diverse physiological processes in complex signalling pathways. It is necessary for plants to continuously regulate cytokinin distribution among different organs, tissues, cells, and compartments. Such regulatory mechanisms include cytokinin biosynthesis, metabolic conversions and degradation, as well as cytokinin membrane transport. In our review, we aim to provide a thorough picture of the latter. We begin by summarizing cytokinin structures and physicochemical properties. Then, we revise the elementary thermodynamic and kinetic aspects of cytokinin membrane transport. Next, we review which membrane-bound carrier proteins and protein families recognize cytokinins as their substrates. Namely, we discuss the families of "equilibrative nucleoside transporters" and "purine permeases", which translocate diverse purine-related compounds, and proteins AtPUP14, AtABCG14, AtAZG1, and AtAZG2, which are specific to cytokinins. We also address long-distance cytokinin transport. Putting all these pieces together, we finally discuss cytokinin distribution as a net result of these processes, diverse in their physicochemical nature but acting together to promote plant fitness.

• Klíčová slova
• ABCG14, AZG1, AZG2, PUP14, cytokinin distribution, cytokinin hydrophobicity, cytokinin transport, membrane transport,
• MeSH
• Arabidopsis metabolismus   MeSH
• biologický transport MeSH
• buněčná membrána metabolismus   MeSH
• cytokininy metabolismus   MeSH
• homeostáza MeSH
• hydrofobní a hydrofilní interakce MeSH
• kinetika MeSH
• kořeny rostlin metabolismus   MeSH
• membránové transportní proteiny metabolismus   MeSH
• proteiny huseníčku genetika   MeSH
• regulace genové exprese u rostlin MeSH
• regulátory růstu rostlin metabolismus   MeSH
• signální transdukce fyziologie   MeSH
• termodynamika MeSH
• výhonky rostlin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• cytokininy MeSH
• membránové transportní proteiny MeSH
• proteiny huseníčku MeSH
• regulátory růstu rostlin MeSH