scholarly journals Studies on 3-indoleacetic acid metabolism. VII. Metabolism of radioactive 3-indoleacetic acid by pea roots

1961 ◽  
Vol 36 (6) ◽  
pp. 783-787 ◽  
Author(s):  
W. A. Andreae ◽  
J. R. Robinson ◽  
M. W. H. Van Ysselstein
Keyword(s):  
Indoleacetic Acid ◽  
Acid Metabolism ◽  
Pea Roots

scholarly journals Rapid Effects of Indoleacetic Acid and Ethylene on the Growth of Intact Pea Roots

1975 ◽  
Vol 55 (3) ◽  
pp. 443-447 ◽  
Author(s):  
Wilfried E. Rauser ◽  
Roger F. Horton
Keyword(s):  
Indoleacetic Acid ◽  
Pea Roots

Amino Acid Metabolism in Plants. V. Changes in Basic Indole Compounds and the Development of Tryptophan Decarboxylase Activity in Barley (Hordeum vulgare) during Germination and Seedling Growth

1974 ◽  
Vol 52 (8) ◽  
pp. 698-705 ◽  
Author(s):  
Elnora A. Schneider ◽  
F. Wightman
Keyword(s):  
Amino Acid ◽  
Shoot Growth ◽  
Indoleacetic Acid ◽  
Acid Metabolism ◽  
Indole Alkaloid ◽  
Tryptophan Decarboxylase ◽  
Decarboxylase Activity ◽  
Indole Compounds ◽  
Free Tryptophan ◽  
Potential Precursor

In barley seedlings, tryptophan is the precursor of the simple indole alkaloid gramine, and also of tryptamine, which is important as a potential precursor of the plant growth hormone 3-indoleacetic acid. The present investigation was designed to study the distribution of free tryptophan and its derivatives within the seedlings, and to follow the changes in these compounds with time. Development of the enzyme tryptophan decarboxylase, which catalyzes the conversion of tryptophan to tryptamine, was also studied. An increase in free tryptophan was detected within 2 h of soaking the seed; this compound reached high values in very young tissues, and then declined. Gramine and its precursors, 3-aminomethylindole and N-methyl-3-aminomethylindole, were confined to the shoots; all three compounds appeared together at the inception of shoot growth. Quantitatively, gramine was the most important compound present and reached a concentration of 623 μg/g fresh weight (25 times that of free tryptophan) on the 9th day, and then declined. Isolated embryos were capable of synthesizing gramine at about one quarter the normal rate, indicating that these embryos have a considerable inherent capacity for tryptophan synthesis and are not wholly dependent on tryptophan released by the endosperm. Tryptophan decarboxylase and tryptamine were found only in the shoot, and both enzyme and product appeared after the 1st week of growth, when the rate of gramine synthesis was beginning to decline. 5-Hydroxytryptamine began to accumulate in both shoot and root after about 2 weeks of growth, and N-methyl-5-hydroxytryptamine was also present in the roots. The close parallel between the gramine pathway of the barley shoot and the analagous hordenine pathway of the root, in which tyrosine is the precursor amino acid, is discussed.

scholarly journals Transgenic Tobacco Plants Coexpressing the Agrobacterium tumefaciens iaaM and iaaH Genes Display Altered Growth and Indoleacetic Acid Metabolism

1992 ◽  
Vol 99 (3) ◽  
pp. 1062-1069 ◽  
Author(s):  
Folke Sitbon ◽  
Stéphane Hennion ◽  
Björn Sundberg ◽  
C. H. Anthony Little ◽  
Olof Olsson ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Transgenic Tobacco ◽  
Indoleacetic Acid ◽  
Acid Metabolism ◽  
Transgenic Tobacco Plants ◽  
Tobacco Plants

STUDIES ON INDOLEACETIC ACID METABOLISM: I. THE EFFECT OF METHYL UMBELLIFERONE, MALEIC HYDRAZIDE, AND 2,4-D ON INDOLEACETIC ACID OXIDATION

1953 ◽  
Vol 31 (4) ◽  
pp. 426-437 ◽  
Author(s):  
W. A. Andreae ◽  
Shirley R. Andreae
Keyword(s):  
Hydrogen Peroxide ◽  
Indoleacetic Acid ◽  
Acid Metabolism ◽  
Maleic Hydrazide ◽  
Acid Oxidation ◽  
Coumarin Derivatives ◽  
Stimulatory Action

Evidence is presented that IAA is oxidized with the liberation of hydrogen peroxide, and that the rate of oxidation is limited by a light-activated step. Methyl umbelliferone, maleic hydrazide, and 2,4-D stimulate IAA oxidation, presumably by accelerating the light-activated step. The stimulatory action of all three substances is overcome to a greater or less extent by scopoletin, which competitively inhibits the oxidation of IAA. It is suggested that maleic hydrazide and methyl umbelliferone may inhibit growth by causing an excessive oxidation of IAA. The importance of fluorescent coumarin derivatives on the photooxidation of IAA in vivo is discussed.

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