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. 1980 Oct;66(4):537–540. doi: 10.1104/pp.66.4.537

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

Gayle H Davidonis 1,2,3, Robert H Hamilton 1,2,3, Ralph O Mumma 1,2,3
PMCID: PMC440673  PMID: 16661472

Abstract

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.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Andreae W. A., Good N. E. The Formation of Indoleacetylaspartic Acid in Pea Seedlings. Plant Physiol. 1955 Jul;30(4):380–382. doi: 10.1104/pp.30.4.380. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bandurski R. S., Schulze A., Cohen J. D. Photo-regulation of the ratio of ester to free indole-3-acetic acid. Biochem Biophys Res Commun. 1977 Dec 21;79(4):1219–1223. doi: 10.1016/0006-291x(77)91136-6. [DOI] [PubMed] [Google Scholar]
  3. Davidonis G. H., Hamilton R. H., Mumma R. O. Metabolism of 2,4-dichlorophenoxyacetic Acid in soybean root callus and differentiated soybean root cultures as a function of concentration and tissue age. Plant Physiol. 1978 Jul;62(1):80–83. doi: 10.1104/pp.62.1.80. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Feung C. S., Hamilton R. H., Witham F. H., Mumma R. O. The relative amounts and identification of some 2,4-dichlorophenoxyacetic Acid metabolites isolated from soybean cotyledon callus cultures. Plant Physiol. 1972 Jul;50(1):80–86. doi: 10.1104/pp.50.1.80. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Feung C., Hamilton R. H., Mumma R. O. Metabolism of 2,4-dichlorophenoxyacetic acid. 10. Identication of metabolites in rice root callus tissue cultures. J Agric Food Chem. 1976 Sep-Oct;24(5):1013–1015. doi: 10.1021/jf60207a011. [DOI] [PubMed] [Google Scholar]
  6. Feung C., Hamilton R. H., Mumma R. O. Metabolism of 2,4-dichlorophenoxyacetic acid. V. Identification of metabolites in soybean callus tissue cultures. J Agric Food Chem. 1973 Jul-Aug;21(4):637–640. doi: 10.1021/jf60188a058. [DOI] [PubMed] [Google Scholar]
  7. Feung C., Hamilton R. H., Mumma R. O. Metabolism of 2,4-dichlorophenoxyacetic acid. VII. Comparison of metabolities from five species of plant tissue cultures. J Agric Food Chem. 1975 May-Jun;23(3):373–376. doi: 10.1021/jf60199a065. [DOI] [PubMed] [Google Scholar]
  8. Kopcewicz J., Ehmann A., Bandurski R. S. Enzymatic Esterification of Indole-3-acetic Acid to myo-Inositol and Glucose. Plant Physiol. 1974 Dec;54(6):846–851. doi: 10.1104/pp.54.6.846. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Venis M. A. Auxin-induced Conjugation Systems in Peas. Plant Physiol. 1972 Jan;49(1):24–27. doi: 10.1104/pp.49.1.24. [DOI] [PMC free article] [PubMed] [Google Scholar]

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