The effect of auxin application on auxin metabolism was investigated in excised hypocotyl cultures of carrot (Daucus carota). Concentrations of both free and conjugated indole-3-acetic acid (IAA), [2H4]IAA, 2,4-dichlorophenoxyacetic acid, and naphthaleneacetic acid (NAA) were measured by mass spectroscopy using stable-isotope-labeled internal standards. [13C1]NAA was synthesized for this purpos...

Chlorophenoxy herbicides are widely used in agriculture and forestry, for the control of broad-leaved weeds in pastures, cereal crops, as well as along public rights of way. Structurally, these herbicides consist of a simple aliphatic carboxylic acid moiety attached to a chlorine-substituted aromatic ring via an ether linkage. One of the most commonly used herbicides of this type is 2,4-dichlor...

The concentrations of indole-3-acetic acid (IAA), naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) were followed for 35 days in cell-free liquid medium containing 100, 50, or 0% Murashige-Skoog (MS) salt base. Although the concentrations of NAA or 2,4-D remained constant the level of IAA decreased to only 11% of the original concentration after 35 days in the presence of ...