Rhythmic fluctuation in the basipetal movement of auxin occurs in corn (Zea mays) coleoptiles oriented either in the vertical or in the horizontal position. This periodicity of transport rate varies from region to region in a horizontal coleoptile. Between an upper and lower half coleoptile (with respect to gravity), the comparable regions in the coleoptile do not exhibit similar periods. The v...

Three auxin analogs, 4-, 5-, and 6-azido-3-indoleacetic acid (4-N(3)-IAA, 5-N(3)-IAA, and 6-N(3)-IAA) have been synthesized for use as fluorescent photoaffinity labeling agents. The pK(a) values of these compounds (4-N(3)-IAA, 4.67; 5-N(3)-IAA, 4.65; 6-N(3)-IAA, 4.66; all +/- 0.04) are experimentally indistinguishable from the pK(a) of 3-indoleacetic acid (IAA, 4.69 +/- 0.04). The auxin activit...

This paper describes a new method for qualitative and quantitative assay of abscisic acid and other acidic plant hormones, such as indoleacetic acid and the gibberellins, by the gas-liquid chromatography of their trimethylsilyl derivatives. Interfering substances in plant extracts were largely removed by preliminary column chromatography with carbon-celite and elution of the abscisic acid with ...

Microelectrode and tracer techniques were used to test for possible amino acid-H(+) co-transport in coleoptiles of Avena sativa L. cv. "Garry." The amino acid analogue alpha-aminoisobutyric acid (AIB) caused transient depolarization of the membrane potential. The absolute magnitude of the maximum depolarization was affected by the same factors that affected AIB transport. Both increased with hi...

Abstract Melatonin ( N -acetyl-5-methoxytriptamine) is a novel plant regulatory molecule currently under study. Its role as biostimulator and protector against abiotic biotic stressors, through the regulation of redox network change in expression many elements primary secondary metabolism, great interest. The possible protective effect melatonin mungbean seedlings, previously primed seed treate...

Four new metabolites related to IAA (indole-3-acetic acid) were isolated from an aqueous methanol extract of rice bran and were elucidated by spectroscopic methods to be a pair of diastereomers of 5-O-β-D-glucopyranosyl 3,5-dihydroxy-2-indolinone-3-acetic acid (A-1 and A-2) and of 5-O-β-D-cellobiosyl 3,5-dihydroxy-2-indolinone-3-acetic acid (B-1 and B-2). Compound B-1 was also a diastereomer of...