The first isolated cytokinin, 6-furfurylaminopurine (kinetin or Kin), was identified almost 55years ago. Its biological effects on plant cells and tissues include influences on such processes as gene expression, cell cycle, chloroplast development, chlorophyll biosynthesis, stimulation of vascular development, delay of senescence, and mobilization of nutrients. In the present study we prepared a series of eight N9-substituted Kin derivatives, and characterized them with available physicochemical methods such as CI+ mass spectrometry and (1)H NMR spectroscopy. All compounds were tested in three classical cytokinin bioassays: a tobacco callus assay, an Amaranthus assay, and a senescence assay with excised wheat leaves. The ability of the compounds to interact with Arabidopsis cytokinin receptors CRE1/AHK4 and AHK3 was tested in a bacterial receptor assay. Prepared derivatives with certain substitutions of the N9-atom of the purine moiety enhanced the cytokinin activity of the parent compound in the bioassays to a remarkable degree but negatively affected its perception by CRE1/AHK4 and AHK3. The ability of compounds to delay the senescence of excised wheat leaves in both dark and light conditions, was highly correlated with their ability to influence membrane lipid peroxidation, which is a typical symptom of senescence. Our results were corroborated by gene expression profiling of those genes involved in cytokinin metabolism and perception, plant senescence, and the stress response, and suggest that prepared kinetin derivatives might be used as potent anti-senescence agents.

Centre of the Region Haná for Biotechnological and Agricultural Research Faculty of Science Palacký University Olomouc Czech Republic

Citace poskytuje Crossref.org

Plant hormone cytokinin at the crossroads of stress priming and control of photosynthesis

Cytokinin N-glucosides: Occurrence, Metabolism and Biological Activities in Plants

Hormopriming to Mitigate Abiotic Stress Effects: A Case Study of N 9-Substituted Cytokinin Derivatives With a Fluorinated Carbohydrate Moiety

Naturally Occurring and Artificial N9-Cytokinin Conjugates: From Synthesis to Biological Activity and Back

Role of Cytokinins in Senescence, Antioxidant Defence and Photosynthesis

Cytokinin-Specific Glycosyltransferases Possess Different Roles in Cytokinin Homeostasis Maintenance

N9-substituted aromatic cytokinins with negligible side effects on root development are an emerging tool for in vitro culturing

Novel cytokinin derivatives do not show negative effects on root growth and proliferation in submicromolar range