Changes in free amino acid pools can predict the mode of action of herbicides

Abstract

Studies were conducted to determine the short‐term changes in free amino acid levels in the meristematic zone of maize after treatment with various herbicides with different modes of action. These herbicides included inhibitors of various amino acid biosynthetic pathways, photosynthesis, and fatty acids biosynthesis. Inhibitors of various amino acid biosynthetic pathways caused specific reduction in the pools of amino acids being produced by the particular pathway. Inhibitors of other metabolic pathways also caused significant changes in pools of various amino acids. Very similar changes in the pools of amino acids were seen in plants treated with different chemical classes of inhibitors affecting a certain metabolic pathway. However, the changes were quite different between inhibitors of different metabolic processes. The data generated from these studies could be used as a diagnostic tool to determine the mode of action of novel herbicides.

Iminodipropionic Acid as the Leaving Group for DNA Polymerization by HIV‐1 Reverse Transcriptase

“…Even so, it is difficult to establish whether it means that the origin of these increased proportions is biosynthesis. It has been proposed that the free amino acid profile after the inhibition of a specific biosynthetic pathway is characteristic 34. Nevertheless, while metabolite measurements provide some indication of a form of general amino acid control in plants,35 evidence in support of coordinated regulation of amino acid biosynthesis enzymes is scarce 36…”

Action of fentrazamide on protein metabolism and cell division in plants

“…[6][7][8] We examined the change of soluble amino acid composition in fentrazamide, cafenstrole or mefenacet-treated early watergrass and rice, because herbicides with the same mode of action show a similar pattern of changes in amino acid composition. 16) From the results of amino acid determination, fentrazamide seems to have a mode of action similar to that of cafenstrole in early watergrass ( Table 1), suggesting that this herbicide would inhibit fatty acid elongation; however, the inhibition of fatty acid elongation by fentrazamide in early watergrass required higher concentrations than that for the inhibition of plant growth (Fig. 3).…”

Chiral effects of (R)‐/(S)‐1‐(α‐methylbenzyl)‐3‐(p‐tolyl)urea on the free amino acid levels in the root tips of rice and wheat

“…Changes in the amount of each free amino acid in a living cell are an important indicator of the effect of drugs on metabolic pathways (Rhodes et al . 1986; Brunk & Rhodes 1988; Singh & Shaner 1995; Starratt & Lazarovits 1996; Wakabayashi & Böger 2002; Deng 2005; Hjorth et al . 2006).…”