title: N9-substituted aromatic cytokinins with negligible side effects on root development are an emerging tool for in vitro culturing.
abstract: Natural cytokinins as well as the majority of their synthetic derivatives show negative effects on root growth and development. Changes in morphology, primarily linked to the inhibition of the cell division in the meristematic zone, are manifested as thickening and shortening of the primary root and impaired lateral root branching. Rational design of cytokinin derivatives can partially overcome these drawbacks and reduce the negative effects. Using our database of cytokinin derivatives, we selected several aromatic cytokinin analogs with modifications at the N9 atom of the adenine moiety. We found that tetrahydropyranyl and tetrahydrofuranyl substitutions at the N9 atom led to enhanced acropetal transport of the modified cytokinin, and both derivatives also showed weak anticytokinin activity. Consequently, changes in the distribution of the active cytokinin pool together with gradual metabolic conversion of the modified cytokinin to its free form prevent root growth inhibition that limits cytokinin utilization in micropropagation techniques.
authors.affiliation: Centre of the Region Haná for Biotechnological and Agricultural Research; Faculty of Science; Palacký University; Olomouc, Czech Republic.
authors.forename: Ondřej
authors.initials: O
authors.lastname: Plíhal
authors.forename: Lucie
authors.initials: L
authors.lastname: Szüčová
authors.forename: Petr
authors.initials: P
authors.lastname: Galuszka
mesh_terms: D046508:Culture Techniques; D003583:Cytokinins / Q000737:chemistry* / Q000494:pharmacology*; D063245:Plant Development / Q000187:drug effects*; D018517:Plant Roots / Q000187:drug effects*; D003313:Zea mays
chemical_list: D003583:Cytokinins
keywords: N9-substituted cytokinins; biotechnology; cytokinin; inhibition; micropropagation; root; tissue culture