Effect of Various Herbicides on Glucose Metabolism in Root Tissue of Garden Peas, Pisum sativum. I. 2,4-Dichlorophenoxyacetic Acid & Its Analogs

Abstract

Carbon-14 labeled glucose was used to measure the effect of several phenoxyacetic acids on absorption, respiratory metabolism and assimilation of carbon atoms into cellular residue. Although the phenoxy acids inhibit glucose absorption the herbicidal properties of some of them are not due to a simple absorption inhibition. Both herbicidal active and inactive compounds inhibit glucose absorption. Low concentrations of 2,4-D acid cause a slight stimulation of glycolysis while high concentrations inhibit both glycolysis and pentose pathway activity. Glycolysis, however, was more strongly inhibited. No significant difference was observed with respect to the tissue components except at high concentrations there was an accumulation of soluble intermediates and a decrease in metabolic end products. The amount of glucose carbon (C-1, C-6 or C-U) utilized for cell wall synthesis was dependent on 2,4-D concentration. The C6/C1 ratio for cellular synthesis was generally not affected. The herbicidal activity of 2,4-D and 2,4,5-T is not singularly due to their effects on glucose metaboism since both herbicidally active and inactive compounds caused similar effects.