Effects of 2,4-Dichlorophenoxyacetic Acid, Antiauxins, and Metabolic Perturbations on Cytoplasmic and Vacuolar pH of Corn Root Tips Measured by in Vivo31P-NMR

Callus induction (CI) and later shoot induction (SI) were studied in Leucocoryne purpurea, a native and endemic Chilean geophyte species. Basal leaf portions (BL), bulb basal plate (BP), and root tips (RT) from in vitro plants were used as explants. Treatments for CI included all three explants and media containing different sources and concentrations of auxins and cytokinins as plant growth regulators (PGRs). Plant material was initiated on MS basal medium (Murashige and Skoog, 1962), supplemented with vitamins, 30 g·L-1 sucrose, 6.0 g·L-1 agar and pH adjusted to 5.7 before autoclaving. The experiments were carried on a growth chamber at 24 ± 1.5 °C. CI cultures were maintained in darkness for 16 weeks, and SI for 12 weeks in a 16-hour photoperiod. BL and RT explants did not respond to any of the CI treatments. BP explants cultured on MS basal medium without PGRs also did not produce any callus. The average frequency of callus induction for BP was 78% and the average fresh weight of callus was 10.06 g/explant after 16 weeks of culture. Best treatment for CI was BP cultured on 4.52 μm 2,4-dichlorophenoxyacetic acid (2,4-D) in combination with 0.45 μm 6-benzyladenine (BA), when they were compared to 2,4-D alone or picloram as auxin source. After 16 weeks of culture, calli were transferred to SI medium, supplemented with three different concentrations of thidiazuron (TDZ), either intact or subdivided (150 mg/explant). SI treatments had a greater and significant response when the callus came from a CI medium containing auxin and cytokinin combined, in comparison to those coming from a CI medium containing auxins only.

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Effect of Auxins (2,4-Dichlorophenoxyacetic acid, Indole-3-Acetic Acid and Naphthaleneacetic Acid) on the Accumulation of γ-Aminobutyric Acid in Excised Rice Root Tips

Plant and Cell Physiology ◽

10.1093/oxfordjournals.pcp.a077532 ◽

1988 ◽

Keyword(s):

Acetic Acid ◽

Rice Root ◽

Aminobutyric Acid ◽

Dichlorophenoxyacetic Acid ◽

Naphthaleneacetic Acid ◽

Root Tips ◽

2,4 Dichlorophenoxyacetic Acid ◽

Indole 3 Acetic Acid

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Substrate Specificity of Carboxylesterase from Vicia faba Roots

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19922181 ◽

1992 ◽

Vol 57 (10) ◽

pp. 2181-2186

Author(s):

Jana Barthová ◽

Hana Löfellmannová ◽

Karel Beneš

Keyword(s):

Substrate Specificity ◽

Vicia Faba ◽

Electrophoretic Analysis ◽

Dichlorophenoxyacetic Acid ◽

Root Tips ◽

Michaelis Constants ◽

2,4 Dichlorophenoxyacetic Acid ◽

Naphthyl Acetate

Michaelis constants values and limiting rates of the reaction catalyzed by carboxylesterase isolated from the root tips of Vicia faba were determined. 1-Naphthyl acetate, 1-naphthyl butyrate, 1-naphthyl ester of N-acetylglycine, 1-naphthyl ester of L-leucine and 1-naphthyl ester of N-acetyl-L-leucine were used as substrates. The values for the enzyme from control plants were compared with the data for carboxylesterase from plants exposed to the effect of 2,4-dichlorophenoxyacetic acid. An electrophoretic analysis of enzymes from control plants and the tested plants was carried out.

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THE EFFECTS OF INDOLEACETIC ACID AND 2,4-DICHLOROPHENOXYACETIC ACID ON THE UPTAKE AND METABOLISM OF 14C-GLUCOSE AND ON THE INCORPORATION OF 14C-LABELLED AMINO ACIDS INTO PROTEIN IN PEA ROOT TIPS

Canadian Journal of Botany ◽

10.1139/b67-181 ◽

1967 ◽

Vol 45 (9) ◽

pp. 1751-1760 ◽

Cited By ~ 6

Author(s):

W. K. Kim ◽

R. G. S. Bidwell

Keyword(s):

Amino Acids ◽

Indoleacetic Acid ◽

Sugar Metabolism ◽

Dichlorophenoxyacetic Acid ◽

Root Tips ◽

Pea Root ◽

Main Effect ◽

2,4 Dichlorophenoxyacetic Acid ◽

Rates Of Growth ◽

Uptake And Metabolism

The effect of indoleacetic acid and 2,4-dichlorophenoxyacetic acid on the uptake and metabolism of 14C-labelled glucose and amino acids by excised pea root tips was studied. The intention was to determine whether the observed reduction of root growth by growth hormones was caused by interference in the uptake or in the metabolism of compounds by roots. The results indicate that the main effect of auxins on sugar metabolism in root tips is not on uptake, but on the subsequent metabolism of glucose. Auxins also had several specific rather than general effects on the synthesis of proteins. The production of certain amino acids from glucose was prevented, and the entry of others into protein was affected. This indicates that effects of auxin on protein metabolism were specific, and not necessarily merely consequences of decreased rates of growth and metabolism.

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In Vitro Shoot Regeneration from Callus Derived from Marubakaido Apple Rootstock under Different Aluminium Concentrations

HortScience ◽

10.21273/hortsci.33.3.460e ◽

1998 ◽

Vol 33 (3) ◽

pp. 460e-460 ◽

Cited By ~ 1

Author(s):

Marisa F. de Oliveira ◽

Gerson R. de L. Fortes ◽

João B. da Silva

Keyword(s):

Shoot Regeneration ◽

Dichlorophenoxyacetic Acid ◽

Apple Rootstock ◽

Under Five ◽

Significant Difference ◽

Previously Treated ◽

2,4 Dichlorophenoxyacetic Acid ◽

In Vitro Shoot Regeneration

The aim of this work was to evaluate the organogenesis of Marubakaido apple rootstock under different aluminium concentratons. The explants were calli derived from apple internodes treated with either 2,4-dichlorophenoxyacetic acid or pichloram at 0.5 and 1.0 μM and under five different aluminium concentrations (0, 5, 10, 15, 20 mg/L). These calli were then treated with aluminium at 0, 5, 10, 15, and 20 mg/L. It was observed shoot regeneration only for those calli previously treated with pichloram. There were no significant difference among the aluminium concentrations.

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Characterization of the Reproductive Mode in Guayule In Vitro

HortScience ◽

10.21273/hortsci.33.3.483a ◽

1998 ◽

Vol 33 (3) ◽

pp. 483a-483

Author(s):

Roy N. Keys ◽

Dennis T. Ray ◽

David A. Dierig

Keyword(s):

Field Experiments ◽

Reproductive Mode ◽

Dichlorophenoxyacetic Acid ◽

Initial Field ◽

Breeding Lines ◽

Reproductive Modes ◽

Desert Southwest ◽

2,4 Dichlorophenoxyacetic Acid

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

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The role of a metabolic intermediate in the biodegradation of inhibitory substrates

Water Science & Technology ◽

10.2166/wst.1997.0352 ◽

1997 ◽

Vol 36 (10) ◽

pp. 27-36 ◽

Cited By ~ 1

Author(s):

P. Mungkarndee ◽

S. M. Rao Bhamidimarri ◽

A. J. Mawson ◽

R. Chong

Keyword(s):

The Other ◽

Metabolic Product ◽

Dichlorophenoxyacetic Acid ◽

Mutual Inhibition ◽

Metabolic Intermediate ◽

Batch Cultures ◽

Ortho Cresol ◽

2,4 Dichlorophenoxyacetic Acid

Biodegradation of the mixed inhibitory substrates, 2,4-dichlorophenoxyacetic acid (2,4-D) and para-chloro-ortho-cresol (PCOC) was studied in aerobic batch cultures. Each substrate added beyond certain concentrations inhibited the degradation of the other. This mutual inhibition was found to be enhanced by 2,4-dichlorophenol (2,4-DCP) which is an intermediate metabolic product of 2,4-D. When 2,4-DCP accumulated to approximatelY 40 mg/l degradation of all compounds in the mixed 2,4-D and PCOC substrate system was completely inhibited. The degradation of 2,4-D and PCOC individually was also found to be inhibited by elevated concentrations of 2,4-DCP added externally, while PCOC inhibited the utilization of the intermediate.

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