The rate of incorporation of glucose into the galacturonic acid residues of pectin has been shown to be modified by the auxin, indoleacetic acid (1). In recent experiments, Loewus, Kelly, and Neufeld (2, 3) have shown that myo-inositol is also a good precursor of the uranic acid of pectin. These workers suggest that myo-inositol is oxidatively cleaved to form glucuronic acid. The latter might b...

For several years we have studied the metabolism of applied indoleacetic acid (IAA) by plant tissues to determine whether growth stimulation or inhibition by IAA could be in any way related to its metabolism. So far we have been chiefly concerned with IAA metabolism by pea epicotyls, and in previous publications (2, 3, 4) have suggested that the toxic action of IAA might be related to the accum...

During indoleacetic acid (IAA) oxidation by horseradish peroxidase the water soluble model polyene, crocin, is bleached. IAA-oxidation and crocin bleaching are stimulated at acidic pH as well as by the monophenol p-hydroxyacetophenone. IAA oxidation and crocin bleaching are neither influenced by catalase or superoxide dismutase nor by different OH-radical scavengers, whereas both ascorbate and ...

We report the nucleotide sequences of iaaM and iaaH, the genetic determinants for, respectively, tryptophan 2-monooxygenase and indoleacetamide hydrolase, the enzymes that catalyze the conversion of L-tryptophan to indoleacetic acid in the tumor-forming bacterium Pseudomonas syringae pv. savastanoi. The sequence analysis indicates that the iaaM locus contains an open reading frame encoding 557 ...

Protein extracts were obtained from climacteric fruits (pear, tomato) and nonclimacteric fruits (blueberry) during various stages of ripening. The use of a gel electrophoresis technique revealed a consistent reinforcement in indoleacetic acid oxidase but not in peroxidase isozymes during ripening. The significance of the results is discussed in relation to the resistance of fruits to ripening a...

We have shown that amide-linked IAA (indole-3-acetic acid) conjugates accumulated to high levels during maturation of bean seeds (K. Bialek and J.D. Cohen [1989] Plant Physiol 91: 775-779). In the present study, we were interested in the fate of these and other IAA conjugates during seed germination. The content of amide-linked conjugates of IAA in cotyledons declined dramatically during the fi...

To study the effect of low molecular weight antioxidants on respiration process, content auxins and abscisic acid, 15-day-old potato (Solanum tuberosum) tubers grown under laboratory conditions were sprayed with 5.8 μM sodium selenite solution or 0.1 mM caffeic acid solution. Control runners treated water. Hypothermia (-2 °C) simulating freezing was created for 2 hours. 21-day-old analyzed. Und...

The objective of this work was to assess the regulatory effects of auxin‐priming on gas exchange and hormonal homeostasis in spring wheat subjected to saline conditions. Seeds of MH‐97 (salt‐intolerant) and Inqlab‐91 (salt‐tolerant) cultivars were subjected to 11 priming treatments (three hormones x three concentrations + two controls) and evaluated under saline (15 dS m‐1) and nonsaline (2.84 ...

A test mixture of five phytohormones [naphthaleneacetic acid (NAA), naphthoxyacetic acid (NOA), indoleacetic acid (IAA), indolebutyric acid (IBA), and indolepropionic acid (IPA)] was investigated. These compounds were cleanly separated with good resolution by capillary zone electrophoresis with a UV diode array detector using 20 mM sodium phosphate buffer (pH 7.25). The lowest detection limit w...