Metabolism of 2,4-dichlorophenoxyacetic acid in cell suspension cultures of soybean (Glycine max L.) and wheat (Triticum aestivum L.) : I. General results.

The metabolism of [2-(14)C]- and [ring-U-(14)C]2,4-dichlorophenoxyacetic acid (2,4-D) has been studied in cell suspension cultures of soybean (Glycine max L.) and wheat (Triticum aestivum L.). 2,4-D was extensively metabolized by both cultures, the rates of metabolism and the metabolite patterns remaining constant over at least 60 (soybean) and 25 (wheat) growth cycles. Amino acid conjugates were the predominant metabolite fraction in soybean cells whereas β-D-glucoside conjugates predominated in wheat cells. The two cell types studied also differed in the amino acid compositions of the amino acid conjugate fractions and in the aglycone patterns of the β-D-glucoside fractions. Novel metabolite fractions of both wheat and soybean cells included a polar water-soluble metabolite fraction and a covalently modified protein fraction of low molecular weight.