The Mechanisms and Effects of Plant-Activation of Chemicals in the Environment

Abstract

Plants can activate promutagens into stable mutagens and these genotoxic agents may be hazardous to the environment and to the public health. Using m-phenylenediamine (m-PDA) as a archetype compound we developed a working model for plant-activation. (1) The aromatic amine is transported into the plant cell, (2) intracellular peroxidase oxidizes the molecule (3) the metabolite is conjugated to a macromolecule, (4) the amine-conjugate is secreted into the extracellular medium, (5) the conjugate or a deconjugated plant-activated metabolite is absorbed by the Salmonella tester strains, (6) the plant-activated N-hydroxylated product is acetylated and deacetylated by the bacterial ACETYLCoA: N-hydroxyarylamine 0-acetyltransferase, and (7) the deacetylation results in a highly reactive nitrenium ion that can react with or adduct to DNA. The relative potency of six plant-activated aromatic amines is 2-aminofluorene > benzidine > m-phenylenediamine > 4aminobiphenyl > 2,4-diaminotoluene. 2- Naphthylarmine was not plant-activated. From a structure-function perspective, there appears to be some correlation between free diamino functional groups. These structure-function relationships are expressed by the relative plant- activation potency of m-PDA and 2,4-diaminotoluene, and benzidine and 4aminobiphenyl. The plant-activated products are stable, and are associated with a macromolecule (>300 kDa). The plant-activated product is further metabolized by cells with high acetyl-CoA: N-hydroxyarylamine 0-acetyltransferase activity. The possibility exists that these plant-activated products maybe formed into non-toxic proximal mutagens in intact plants that can be metabolized back into potent frameshift mutagens in organisms that consume the plants.

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Document Details

Document Type
Technical Report
Publication Date
Apr 20, 1992
Accession Number
ADA251876

Entities

People

  • Michael J. Plewa

Organizations

  • University of Illinois Urbana–Champaign

Tags

DTIC Thesaurus Topics

  • Air Force
  • Air Force Facilities
  • Amines
  • Cells
  • Ecology
  • Ecotoxicology
  • Environment
  • Food Chains
  • Illinois
  • Inhibitors
  • Macromolecules
  • Metabolites
  • Microorganisms
  • Molecular Weight
  • Molecules
  • Plant Cells
  • Public Health

Fields of Study

  • Chemistry

Readers

  • Allergy and Immunology.
  • Analytical Chemistry
  • Toxicology/Environmental Toxicology