02832nam a2200469Ia 4500 MX-MdCICY 20260521091800.0 CICY B-21323 Cytokinin oxidase/dehydrogenase inhibitors: progress towards agricultural practice Journal of Experimental Botany. 75(16), 4873-4890, 2024, DOI: 10.1093/jxb/erae239 Cytokinin oxidase/dehydrogenase (CKX) inhibitors reduce the degradation of cytokinins in plants and thereby may improve the efficiency of agriculture and plant tissue culture-based practices. Here, we report a synthesis and structure-activity relationship study of novel urea derivatives concerning their CKX inhibitory activity. The most active compounds showed sub-nanomolar IC50 values with maize ZmCKX1, the lowest value yet documented. Other CKX isoforms of maize and Arabidopsis were also inhibited very effectively. The binding mode of four compounds was characterized based on high-resolution crystal complex structures. Using the soil nematode Caenorhabditis elegans, and human skin fibroblasts, key CKX inhibitors with low toxicity were identified. These compounds enhanced the shoot regeneration of Lobelia, Drosera, and Plectranthus, as well as the growth of Arabidopsis and Brassica napus. At the same time, a key compound (identified as 82) activated a cytokinin primary response gene, ARR5:GUS, and a cytokinin sensor, TCSv2:GUS, without activating the Arabidopsis cytokinin receptors AHK3 and AHK4. This strongly implies that the effect of compound 82 is due to the up-regulation of cytokinin signalling. Overall, this study identifies highly effective and easily prepared CKX inhibitors with a low risk of environmental toxicity for further investigation of their potential in agriculture and biotechnology. © The Author(s) 2024 AGRICULTURE ARABIDOPSIS BIOSTIMULANT BIOTECHNOLOGY CKX INHIBITOR CYTOKININ CYTOKININ OXIDASE/DEHYDROGENASE DIPHENYLUREA NUTRIENT USE EFFICIENCY OILSEED RAPE Nisler J. Klimeš P. Kon?itíková R. Kadlecová A. Voller J. Chalaki M. Karampelias M. Murvanidze N. Werbrouck S.P.O. Kope?ný D. Havlí?ek L. De Diego N. Briozzo P. Moréra S. Zalabák D. Spíchal L. https://drive.google.com/file/d/1Swf68ZqiP0Xtrhg9UvWv6DS-h2zefvwy/view?usp=drivesdk Para ver el documento ingresa a Google con tu cuenta @cicy.edu.mx Loc REF1 250602s9999 xx |||||s2 |||| ||und|d 31327 31327 0 0 Loc 0 0 F1 CICY CICY RE 2025-06-25 0 B-21323 2025-06-25 16:43:53 2025-06-25 REF1