Correlation between inactivation of 2,4-dichlorophenoxyacetic acid & cessation of callus growth in bean stem sections

Abstract

The fate of 2,4-D in bean stem sections in vitro was followed by means of carboxyl-C14-2,4-D. It was found that in the system employed cessation of growth corresponded to the disappearance of any chromatographically demonstrable amounts of free 2,4-D with the concomitant appearance of metabolites of 2,4-D which had different chromatographic characteristics. Reapplication of 2,4-D resulted in a 2d increment of growth equal in magnitude to the first. Very little radioactivity was converted to CO2 in this system and very little was bound to the tissue or transported into the medium. The metabolites mentioned above accounted for better than 80% of the total radioactivity which was absorbed.