Experiments have been performed to investigate whether indoleacetic acid changes the balance between the rates of synthesis of different kinds of proteins. Sub-apical sections of etiolated peas were incubated with (14)C- or (3)H-labeled amino acid, and combined to give dual-labeled tissue. Cell fractions were prepared by differential centrifugation, and the dual-labeled protein of each fraction...

Several cell wall-bound glycosidases present in Avena sativa coleoptiles were assayed by following the hydrolysis of p-nitrophenyl-glycosides. Particular emphasis was placed on characterizing some parameters affecting the activity of beta-galactosidase. The pH optimum of this enzyme is 4.5 to 5.5; it is sensitive to copper ions and p-chloromercuribenzoate treatment and apparently has an excepti...

Root auxanometers were used to determine the growth rates of individual intact primary roots accurately and quickly. The growth of pea (Pisum sativum L.) roots was inhibited by both indoleacetic acid and ethylene within 20 minutes. A supramaximal concentration of ethylene inhibited root growth less than did 5 to 20 mum indoleacetic acid, indicating that inhibition of root growth by auxin was no...

The radioprotective ability of L-tryptophan, tryptamine, 3-indoleacetic and indole (10~4 m), on UV and gamma irradiated DNA (10-4 m) is studied. UV radioprotection is accomplished in the following order of efficiency: L-Tryptophan and 3-indoleacetic acid > indole and tryptamine. The corresponding DRF measured as absorbancy loss at 260 nm, were: L-Tryptophan and 3-indoleacetic acid around 3 and ...

E&acts of pineapple stem tissue constitute the most potent known source of indoleacetic acid oxidase, despite the presence of an inhibitor which is difficult to remove without simultaneously removing some other factor necessary for maximal activity (I). Dialysis invariably lowers the enzyme activity as compared with photolysis, and even prolonged photolysis is never completely effective in remo...

The objective of this study was to examine the substrate specificity of several ruminal strains of a Lactobacillus sp. which previously was shown to produce skatole (3-methylindole) by the decarboxylation of indoleacetic acid. A total of 13 compounds were tested for decarboxylase activity. The Lactobacillus strains produced p-cresol (4-methylphenol) by the decarboxylation of p-hydroxyphenylacet...

The possibility of an auxin effect on the permeability of pea (Pisum sativum L. ev. Alaska) segments to tritium-labeled water has been investigated by three separate laboratories, and the combined results are presented. We were unable to obtain any indication of a rapid effect of indoleacetic acid on the efflux of (3)HHO when pea segments previously "loaded" for 90 minutes with (3)HHO were tran...

Indoleacetic acid and gibberellic acid were added to decapitated lightgrown 'Alaska' pea seedlings as substitutes for the intact apex in the control of apical dotiinance. Of various concentrations and combinations tried, a conrbintation of 1 % indoleacetic acid 1 % gibberellic acid was the most inihibiting to side bud growth. The greatest degree of hormonally induced side bud inhibition was ach...