Abstract.
The effect of benzyladenine (BA) and two phenylurea cytokinins, N-phenyl-N′-(2-chloro-4-pyridyl)urea (4-PU-30) and thidiazuron (TDZ), on the growth, photosynthetic pigment content, and activity of chlorophyllase (chlorophyll-chlorophylliodhydrolase, EC 3.1.1.14) of in vitro cultures of carnations was studied. All cytokinins caused a rise in the fresh weigth and a drop in the dry weight of leaf mass produced by the explanted buds. Both 4-PU-30 and TDZ increased the chlorophyll content and this correlated with changes in chlorophyllase activity. The effect of 4-PU-30 and TDZ was similar to that caused by BA but at 10-fold or 100-fold lower concentrations. The application of higher concentrations of the phenylurea cytokinins caused an increase in the chlorophyll a/chlorophyll b ratio. However, at equimolar concentrations, the purine and both phenylurea cytokinins had opposite effects, probably indirect and related to some malformations caused by phenylureas. 4-PU-30 increased, but TDZ decreased, photosynthetic membrane stability, which argues for a different molecular organization of the chloroplast membranes.
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Received February 26, 1996; accepted May 30, 1997
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Genkov, T., Tsoneva, P. & Ivanova, I. Effect of Cytokinins on Photosynthetic Pigments and Chlorophyllase Activity in in Vitro Cultures of Axillary Buds of Dianthus caryophyllus L.. J Plant Growth Regul 16, 169–172 (1997). https://doi.org/10.1007/PL00006992
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DOI: https://doi.org/10.1007/PL00006992