The phenylquinazoline compound S-4893 is a non-competitive cytokinin antagonist that targets Arabidopsis cytokinin receptor CRE1 and promotes root growth in Arabidopsis and rice.
We identified two phenylquinazoline compounds in a large-scale screening for cytokinin antagonists in yeast expressing the Arabidopsis cytokinin receptor cytokinin response 1/histidine kinase 4 (CRE1). After chemical modifications, we obtained compound S-4893, which non-competitively inhibited binding of the natural ligand 2-isopentenyladenine to CRE1. S-4893 antagonized cytokinin-induced activation of the Arabidopsis response regulator 5 promoter in Arabidopsis. Importantly, S-4893 had no detectable intrinsic cytokinin agonist activity in Arabidopsis or in the transformed yeast system. Cytokinin bioassay further demonstrated that S-4893 antagonized cytokinin-induced stimulation of callus formation and inhibition of root elongation. S-4893 also promoted seminal, crown and lateral root growth in rice, suggesting that S-4893 could potentially promote root growth in a variety of agronomically important plants. We believe S-4893 will be a useful tool in functional studies of cytokinin action in a wide range of plants and a lead compound for the development of useful root growth promoters in agriculture.
Agricultural Chemicals Research Laboratory, Sumitomo Chemical Company Limited, Takarazuka, Hyogo, 665-8555 Japan. aratay@sc.sumitomo-chem.co.jp
Yuto
Y
Arata
Asako
A
Nagasawa-Iida
Hideki
H
Uneme
Hiroki
H
Nakajima
Tatsuo
T
Kakimoto
Ryo
R
Sato
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D003583:Cytokinins / Q000037:antagonists & inhibitors; D004353:Drug Evaluation, Preclinical; D007541:Isopentenyladenosine / Q000494:pharmacology; D012275:Oryza / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D010937:Plant Growth Regulators / Q000037:antagonists & inhibitors; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D011485:Protein Binding; D011494:Protein Kinases / Q000096:biosynthesis / Q000235:genetics; D011799:Quinazolines / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D036226:Seedlings / Q000254:growth & development; D015398:Signal Transduction; D054852:Small Molecule Libraries / Q000138:chemical synthesis; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D003583:Cytokinins; D010937:Plant Growth Regulators; D011799:Quinazolines; D011956:Receptors, Cell Surface; C568585:S-4893 compound; D054852:Small Molecule Libraries; C001478:N(6)-(delta(2)-isopentenyl)adenine; D007541:Isopentenyladenosine; D011494:Protein Kinases; C421783:WOL protein, Arabidopsis