The Relative Amounts and Identification of Some 2,4-Dichlorophenoxyacetic Acid Metabolites Isolated from Soybean Cotyledon Callus Cultures

Feung, Chao-Shieung; Hamilton, Robert H.; Witham, Francis H.; Mumma, Ralph O.

doi:10.1104/pp.50.1.80

Cited by 56 publications

(57 citation statements)

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“…In soybean callus cultures, one of the few plant cells in which 2,4-D metabolism has been studied, the pool of free 2,4-D was metabolized to form 2,4-D conjugates with glutamic (Feung et al, 1971) and aspartic acids (Feung et al, 1972). Like conjugates of IAA (Bialek et al, 1983), 2,4-D conjugates could presumably be hydrolyzed back to the free form.…”

Section: 4-dmentioning

confidence: 99%

“…Like conjugates of IAA (Bialek et al, 1983), 2,4-D conjugates could presumably be hydrolyzed back to the free form. The catabolism of 2,4-D into the predominant glycoside of 4-hydroxy-2,5-dichloroacetic acid and the less-abundant glycosíde of 2,3-dichlorophenoxyacetic acid is one welldefíned degradative pathway in soybean cultures (Feung et al, 1971(Feung et al, , 1972Hamilton et al, 1971). However, in general, 2,4-D is a relatively stable compound that has been shown to be very persistent in carrot cultures (Michalczuk et al, 1992b).…”

Section: 4-dmentioning

confidence: 99%

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The Effects of Exogenous Auxins on Endogenous Indole-3-Acetic Acid Metabolism (The Implications for Carrot Somatic Embryogenesis)

et al. 1996

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(D.M.R., N.I., T.J.C.)l h e effect of auxin application on auxin metabolism was investigated in excised hypocotyl cultures of carrot (Daucus carota). Concentrations of both free and conjugated indole-3-acetic acid (IAA), [2H,]IAA, 2,4-dichlorophenoxyacetic acid, and naphthaleneacetic acid (NAA) were measured by mass spectroscopy using stable-isotope-labeled interna1 standards.[l3C1]NAA was synthesized for this purpose, thus extending the range of auxins that can be assayed by stable-isotope techniques. 2,4-Dichlorophenoxyacetic acid promoted callus proliferation of the excised hypocotyls, accumulated as the free form in large quantities, and had minor effects on endogenous IAA concentrations. NAA promoted callus proliferation and the resulting callus became organogenic, producing both roots and shoots. NAA was found mostly in the conjugated form and had minor effects on endogenous IAA concentrations. [ZH,lIAA had no visible effect on the growth pattern of cultured hypocotyls, possibly because it was rapidly metabolized to form inactive conjugates or possibly because it mediated a decrease in endogenous IAA concentrations by an apparent feedback mechanism. l h e presente of exogenous auxins did not affect tryptophan labeling of either the endogenous tryptophan or IAA pools. This suggested that exogenous auxins did not alter the IAA biosynthetic pathway, but that synthetic auxins did appear to be necessary to induce callus proliferation, which was essential for excised hypocotyls to gain the competence to form somatic embryos.Since the 1940s (Thimann, 1974), exogenous auxins have been used frequently as experimental tools for studying their effects in developing structures (Schiavone and Cooke, 1987); for screening for mutants impaired in the uptake, metabolism, and physiology of endogenous auxins (Timpte et al., 1994); and even to find potential IAA receptors (Jones and Venis, 1989; LoSchiavo et al., 1991). One important use for the application of exogenous auxin is as a growth regulator for maintaining plant-cell-and tissue-

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Section: 4-dmentioning

confidence: 99%

Section: 4-dmentioning

confidence: 99%

The Effects of Exogenous Auxins on Endogenous Indole-3-Acetic Acid Metabolism (The Implications for Carrot Somatic Embryogenesis)

et al. 1996

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“…Some D-amino acid (glutamic acid, valine, or leucine) conjugates of 2,4,-dichlorophenoxyacetic acid (2,4-D) Soybean tissue cultures metabolize the auxin herbicide 2,4-D2 to amino acid and water-soluble (glycosides) conjugates (9,11,12,17,18) …”

Section: Introductionmentioning

confidence: 99%

“…Soybean tissue cultures metabolize the auxin herbicide 2,4-D2 to amino acid and water-soluble (glycosides) conjugates (9,11,12,17,18). Seven L-amino acid conjugates have been isolated and identified (2,4-D glutamic acid, 2,4-D aspartic acid, 2,4-D alanine, 2,4-D valine, 2,4-D leucine, 2,4-D phenylalanine, and 2,4-D tryptophan) (9).…”

mentioning

confidence: 99%

“…

ABSTRACTSome D-amino acid (glutamic acid, valine, or leucine) conjugates of 2,4,-dichlorophenoxyacetic acid (2,4-D) Soybean tissue cultures metabolize the auxin herbicide 2,4-D2 to amino acid and water-soluble (glycosides) conjugates (9,11,12,17,18)

MATERIALS AND METHODSCallus tissue used in these experiments was derived from soybean root (Glycine max L. var. Amsoy 71).

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Biological Properties of d-Amino Acid Conjugates of 2,4-D

Davidonis

Hamilton²,

Vallejo³

et al. 1982

Plant Physiol.

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Some D-amino acid (glutamic acid, valine, or leucine) conjugates of 2,4,-dichlorophenoxyacetic acid (2,4-D) Soybean tissue cultures metabolize the auxin herbicide 2,4-D2 to amino acid and water-soluble (glycosides) conjugates (9,11,12,17,18) MATERIALS AND METHODSCallus tissue used in these experiments was derived from soybean root (Glycine max L. var. Amsoy 71). Callus cultures were grown on an agar-solidified medium (16) with 3% sucrose, kinetin (2.32 AM), and NAA (10 tM). Cultures were maintained at 25°C under continuous fluorescent light (0.5 ,uE/m2. s).For the cell elongation bioassay oat seeds, Avena sativa L. (var. Mariner) were dehusked, surface sterilized in 5% H202 for 20 min and rinsed five times with distilled H20. The sterilized seeds were spread over moist filter paper in glass trays and kept in the dark at approximately 25°C temperature for 24 h. The germinated seeds were then exposed to red light for 4 h (red filtered incandescent lamp) and then allowed to grow in the dark for an additional 48 h. The apical tips were removed (approximately 2 mm) from the coleoptiles and 6.5-mm sections were cut 2 h after the initial decapitation. Ten sections were added to each Petri dish containing 10 ml of basal medium (2% sucrose in 0.01 M KH2PO4) with or without 2,4-D or the amino acid conjugates at concentrations of 1 or 10 ,UM. The coleoptile sections were incubated in the dark for 20 h and then measured. Some experiments with 2,4-D-(D)-leucine were run under sterile conditions. The seeds were surface sterilized in 20%/o commercial bleach (1% NaOCI) plus Tween 20 (0.05%) for 20 min. The seeds were washed five times with sterile H20 and germinated in sterile Pyrex baking dishes. Sections were aseptically cut and transferred to sterile treatment solutions or nutrient agar for checking microbial contamination.For the soybean callus bioassay, four small clumps of tissue (approximately 10 mg each) were aseptically transferred to 125-ml flasks containing 50 ml of medium as previously described.

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Application of plant tissue cultures in phytoremediation research: Incentives and limitations

Doran

2009

Biotech & Bioengineering

154

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The aim of this review is to critically assess the benefits and limitations associated with the use of in vitro plant cell and organ cultures as research tools in phytoremediation studies. Plant tissue cultures such as callus, cell suspensions, and hairy roots are applied frequently in phytoremediation research as model plant systems. In vitro cultures offer a range of experimental advantages in studies aimed at examining the intrinsic metabolic capabilities of plant cells and their capacity for toxicity tolerance. The ability to identify the contributions of plant cells to pollutant uptake and detoxification without interference from microorganisms is of particular significance in the search for fundamental knowledge about plants. However, if the ultimate goal of plant tissue culture experiments is the development of practical phytoremediation technology, the limitations inherent in the use of in vitro cultures as a representative of whole plants in the field must be recognized. The bioavailability of contaminants and the processes of pollutant uptake and metabolite distribution are likely to be substantially different in the two systems; this can lead to qualitative as well as quantitative differences in metabolic profiles and tolerance characteristics. Yet, many studies have demonstrated that plant tissue cultures are an extremely valuable tool in phytoremediation research. The results derived from tissue cultures can be used to predict the responses of plants to environmental contaminants, and to improve the design and thus reduce the cost of subsequent conventional whole plant experiments.

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The Relative Amounts and Identification of Some 2,4-Dichlorophenoxyacetic Acid Metabolites Isolated from Soybean Cotyledon Callus Cultures

Cited by 56 publications

References 8 publications

The Effects of Exogenous Auxins on Endogenous Indole-3-Acetic Acid Metabolism (The Implications for Carrot Somatic Embryogenesis)

The Effects of Exogenous Auxins on Endogenous Indole-3-Acetic Acid Metabolism (The Implications for Carrot Somatic Embryogenesis)

Biological Properties of d-Amino Acid Conjugates of 2,4-D

Application of plant tissue cultures in phytoremediation research: Incentives and limitations

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