Metabolism of 2,4-Dichlorophenoxyacetic Acid (2,4-D) in Soybean Root Callus 1: EVIDENCE FOR THE CONVERSION OF 2,4-D AMINO ACID CONJUGATES TO FREE 2,4-D
Davidonis, Gayle H.
An auxin-requiring soybean root callus metabolized [1-14C]-2,4-dichlorophenoxyacetic acid (2,4-D) to diethyl ether-soluble amino acid conjugates and water-soluble metabolites. The uptake in tissue varied with incubation time, concentration, and amount of tissue. Uptake was essentially complete (80%) after a 24-hour incubation and the percentage of free 2,4-D in the tissue fell to its lowest point at this time. At later times, the percentage of free 2,4-D increased and the percentage of amino acid conjugates decreased, whereas the percentage of water-soluble metabolites increased only slightly. Similar trends were seen if the tissue was incubated for 24 hours in radioactive 2,4-D, followed by incubation in media without 2,4-D for 24 hours. Inclusion of nonlabeled 2,4-D during the 24-hour chase period did not reduce amino acid conjugate disappearance but did reduce the percentage of free [1-14C]2,4-D. Thus, an external supply of 2,4-D does not directly prevent amino acid conjugate metabolism in this tissue. It is concluded that 2,4-D amino acid conjugates were actively metabolized by this tissue to free 2,4-D and water-soluble metabolites.
ACESSO AO ARTIGOhttp://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=440673
- Mineralization of 2,4-Dichlorophenoxyacetic Acid (2,4-D) and Mixtures of 2,4-D and 2,4,5-Trichlorophenoxyacetic Acid by Phanerochaete chrysosporium
- Effect of Dissemination of 2,4-Dichlorophenoxyacetic Acid (2,4-D) Degradation Plasmids on 2,4-D Degradation and on Bacterial Community Structure in Two Different Soil Horizons
- Comparative Metabolism of 2,4-Dichlorophenoxyacetic Acid in Cotyledon and Leaf Callus from Two Varieties of Soybean 1
- Monitoring of the harmful concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) in soils with and without organic matter
- The Relative Amounts and Identification of Some 2,4-Dichlorophenoxyacetic Acid Metabolites Isolated from Soybean Cotyledon Callus Cultures 1