title: Cytokinin oxidase is involved in the regulation of cytokinin content by 24-epibrassinolide in wheat seedlings.
abstract: Fast and stable 2-fold accumulation of cytokinins (CKs) was detected initially in roots and then in shoots of 4-day-old wheat (Triticum aestivum L.) seedlings in the course of their treatment with 0.4μM 24-epibrassinolide (EBR). Elevated cytokinin level has been maintained only in the presence of EBR, while the hormone removal has led to return of cytokinin concentration to the control level initially in the roots and then in the shoots. EBR-induced accumulation of cytokinins was accompanied by inhibition of both cytokinin oxidase (CKX) (cytokinin oxidase/dehydrogenase, EC 1.5.99.12) activity and expression of the gene coding for this enzyme, and on the contrary the decline in CKs level resulted in increase in these characteristics up to the control level in roots and then in shoots. Sharp accumulation of cytokinin O-glucosides has been discovered in response to EBR-treatment suggesting fast EBR-induced activation of production of cytokinins, which excessive amounts were transferred into the storage forms. The obtained data provide evidence for the involvement of EBR in regulation of cytokinin level in wheat seedlings.
authors.affiliation: Institute of Biochemistry and Genetics, Ufa Scientific Centre, Russian Academy of Sciences, Pr. Oktyabrya 71, Ufa 450054, Russia.
authors.forename: Ruslan
authors.initials: R
authors.lastname: Yuldashev
authors.forename: Azamat
authors.initials: A
authors.lastname: Avalbaev
authors.forename: Marina
authors.initials: M
authors.lastname: Bezrukova
authors.forename: Lidia
authors.initials: L
authors.lastname: Vysotskaya
authors.forename: Vladimir
authors.initials: V
authors.lastname: Khripach
authors.forename: Farida
authors.initials: F
authors.lastname: Shakirova
mesh_terms: D060406:Brassinosteroids / Q000494:pharmacology*; D003583:Cytokinins / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005960:Glucosides / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D013260:Steroids, Heterocyclic / Q000494:pharmacology*; D013997:Time Factors; D014908:Triticum / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
chemical_list: D060406:Brassinosteroids; D003583:Cytokinins; D005960:Glucosides; D010940:Plant Proteins; D013260:Steroids, Heterocyclic; D010088:Oxidoreductases; C019984:cytokinin oxidase; C023623:brassinolide