Cytokinins are naturally occurring substances that act as plant growth regulators promoting plant growth and development, including shoot initiation and branching, and also affecting apical dominance and leaf senescence. Aromatic cytokinin 6-benzylaminopurine (BAP) has been widely used in micropropagation systems and biotechnology. However, its 9-glucoside (BAP9G) accumulates in explants, causing root inhibition and growth heterogenity. To overcome BAP disadvantages, a series of ring-substituted 2'-deoxy-9-(β)-d-ribofuranosylpurine derivatives was prepared and examined in different classical cytokinin bioassays. Amaranthus, senescence and tobacco callus bioassays were employed to provide details of cytokinin activity of 2'-deoxy-9-(β)-d-ribosides compared to their respective free bases and ribosides. The prepared derivatives were also tested for their recognition by cytokinin receptors of Arabidopsis thaliana AHK3 and CRE1/AHK4. The ability of aromatic N6-substituted adenine-2'-deoxy-9-(β)-d-ribosides to promote plant growth and delay senescence was increased considerably and, in contrast to BAP, no loss of cytokinin activity at higher concentrations was observed. The presence of a 2'-deoxyribosyl moiety at the N9-position led to an increase in cytokinin activities in comparison to the free bases and ribosides. The antioxidant capacity, cytotoxicity and effect on the MHV-68 gammaherpesvirus strain were also examined.

• MeSH
• antioxidancia chemická syntéza   chemie   farmakologie   MeSH
• Arabidopsis účinky léků   metabolismus   MeSH
• Cercopithecus aethiops MeSH
• molekulární struktura MeSH
• purinové nukleosidy chemická syntéza   chemie   farmakologie   MeSH
• regulátory růstu rostlin chemická syntéza   chemie   farmakologie   MeSH
• Vero buňky MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Isoprenoid cytokinins play a number of crucial roles in the regulation of plant growth and development. To study cytokinin receptor properties in plants, we designed and prepared fluorescent derivatives of 6-[(3-methylbut-2-en-1-yl)amino]purine (N6-isopentenyladenine, iP) with several fluorescent labels attached to the C2 or N9 atom of the purine moiety via a 2- or 6-carbon linker. The fluorescent labels included dansyl (DS), fluorescein (FC), 7-nitrobenzofurazan (NBD), rhodamine B (RhoB), coumarin (Cou), 7-(diethylamino)coumarin (DEAC) and cyanine 5 dye (Cy5). All prepared compounds were screened for affinity for the Arabidopsis thaliana cytokinin receptor (CRE1/AHK4). Although the attachment of the fluorescent labels to iP via the linkers mostly disrupted binding to the receptor, several fluorescent derivatives interacted well. For this reason, three derivatives, two rhodamine B and one 4-chloro-7-nitrobenzofurazan labeled iP were tested for their interaction with CRE1/AHK4 and Zea mays cytokinin receptors in detail. We further showed that the three derivatives were able to activate transcription of cytokinin response regulator ARR5 in Arabidopsis seedlings. The activity of fluorescently labeled cytokinins was compared with corresponding 6-dimethylaminopurine fluorescently labeled negative controls. Selected rhodamine B C2-labeled compounds 17, 18 and 4-chloro-7-nitrobenzofurazan N9-labeled compound 28 and their respective negative controls (19, 20 and 29, respectively) were used for in planta staining experiments in Arabidopsis thaliana cell suspension culture using live cell confocal microscopy.

• MeSH
• 4-chlor-7-nitrobenzofurazan farmakologie   MeSH
• adenin analogy a deriváty   chemie   MeSH
• Arabidopsis metabolismus   MeSH
• barvicí látky chemie   MeSH
• cytokininy chemie   farmakologie   MeSH
• fluorescenční barviva chemie   MeSH
• isopentenyladenosin chemická syntéza   chemie   farmakologie   MeSH
• karbocyaniny chemie   MeSH
• konfokální mikroskopie MeSH
• kukuřice setá metabolismus   MeSH
• molekulární struktura MeSH
• proteiny huseníčku metabolismus   MeSH
• puriny chemie   MeSH
• receptory cytokinové antagonisté a inhibitory   chemie   MeSH
• regulace genové exprese u rostlin MeSH
• regulátory růstu rostlin metabolismus   MeSH
• rhodaminy chemie   MeSH
• semenáček metabolismus   MeSH
• terpeny metabolismus   MeSH
• vývoj rostlin MeSH
• Publikační typ
• časopisecké články MeSH