Abstract
Thidiazuron, a synthetic phenylurea-type cytokinin, has previously beenfound to induce somatic embryogenesis and organogenesis in a wide range ofplantspecies and to modulate the metabolism of endogenous auxins and cytokinins. Inspite of these findings, the precise mode of action of TDZ remainsundetermined.The current studies were undertaken to determine the fate of the TDZ moleculeand the effects of TDZ exposure on auxin transport in plants. The fate of tworadiolabelled versions of thidiazuron, [14C-5-thidiazol]-TDZ and[14C-U-phenyl]-TDZ, was investigated in sterile hypocotyl culturesofgeranium (Pelargonium × hortorumBailey). Radiolabelled TDZ was recovered from the tissue explants inethanol-insoluble, ethanol-soluble and chloroform fractions as well as inacidic, basic and neutral eluants from Dowex resins. Hypocotyl sections thathadbeen exposed to TDZ were found to accumulate more 14C-IAA from theculture medium and to translocate the auxin over a greater distance within thetissues. These data provide the first evidence that the TDZ molecule remainsintact in both a free and conjugated form within the plant tissues and providesome indication that TDZ-exposure enhances the accumulation and translocationofauxin within the tissues.
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Murch, S.J., Saxena, P.K. Molecular fate of thidiazuron and its effects on auxin transport in hypocotyls tissues of Pelargonium × hortorum Bailey. Plant Growth Regulation 35, 269–275 (2001). https://doi.org/10.1023/A:1014468905953
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DOI: https://doi.org/10.1023/A:1014468905953