Uptake and Conversion of Three Different 5-Ring Polycyclic Aromatic Hydrocarbons (PAHs) in Cell Suspension Cultures of Various Chenopodiaceae-Species

Abstract

Three l4C-labelled 5-ring PAHs, benzo(a)pyrene, dibenz(a,h)anthracene and perylene were added to various cell suspension cultures of plants belonging to the Chenopodiaceae family. The differently configurated 5-ring systems varied in uptake and metabolism. The uptake of benzo(a)pyrene was highest in all cell cultures tested whereas the assimilation of dibenz(a,h)an­thracene and perylene was significantly less. The uptake of benzo(a)pyrene and dibenz(a,h)- anthracene was highest in those cultures which showed the highest increase in biomass. In contrast the uptake of perylene was highest in cultures whose increase in biomass was less. Previous investigations (H. Harms, W. Dehnen and W. Monch, Z. Naturforsch. 32 c, 321 -326 (1977)) showed that benzo(a)pyrene is metabolized to quinones and other oxygenated derivatives by Chenopodium rubrum cell cultures. It was demonstrated now that in further reactions these compounds are incorporated into insoluble fractions. With increasing time of incubation the amount of radioactivity in the extracted residue increased. The proportion of oxygenated derivatives formed seems to be correlated with the incorporation of radioactivity into insoluble fractions. Dibenz(a,h)anthracene turned out to be the most stable 5-ring system whereas perylene is metabolized to a certain extent but only small amounts of radioactivity could be detected in the extracted insoluble residue. The experiments showed that plant cell cultures maintain their specific behaviour over long periods. On the other hand each of the chemical compounds, because of its molecular size and configuration, is subject to its own specific metabolism in plant systems.