Uptake and Transformation of Benzene and Toluene by Plant Leaves

• Published in: Ecotoxicology and environmental safety 1997-06, Vol.37 (1), p.24-29
• Main Authors: Ugrekhelidze, Devi, Korte, Friedhelm, Kvesitadze, George
• Format: Article
• Language: English
• Subjects: Absorption; ACER CAMPESTRE; Amino Acids - metabolism; Animal, plant and microbial ecology; Applied ecology; AROMATIC HYDROCARBONS; Benzene - pharmacokinetics; Biological and medical sciences; Biotransformation; Chloroplasts - enzymology; Chloroplasts - metabolism; CONTAMINANTES; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; FEUILLE; Fruit - metabolism; Fundamental and applied biological sciences. Psychology; HIDROCARBUROS AROMATICOS; HOJAS; HYDROCARBURE AROMATIQUE; Hydroxylation; LEAVES; MALUS PUMILA; Non agrochemicals pollutants; Oxidation-Reduction; Phytopathology. Animal pests. Plant and forest protection; Plant Leaves - enzymology; Plant Leaves - growth & development; Plant Leaves - metabolism; POLLUANT; POLLUTANTS; Pollution effects and side effects of agrochemicals on crop plants and forest trees. Other anthropogenic factors; Pollution effects. Side effects of agrochemicals; SPINACIA OLERACEA; Spinacia oleracea - metabolism; Subcellular Fractions - enzymology; Subcellular Fractions - metabolism; Toluene - pharmacokinetics; Trees - metabolism; VITIS VINIFERA
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1006/eesa.1996.1512

The [1-6 14C]benzene and [1- 14C]toluene vapors penetrate into hypostomatous leaves of Acer campestre, Malus domestica,and Vitis viniferafrom both sides, whereas hydrocarbons are more intensively absorbed by the stomatiferous side and more actively taken up by young leaves. Benzene and toluene conversion in leaves occurs with the aromatic ring cleavage and their carbon atoms are mainly incorporated into nonvolatile organic acids, while their incorporation into amino acids is less intensive. Intact spinach chloroplasts oxidize benzene, and this process is strongly stimulated in light. Oxidation of benzene by spinach chloroplasts or by enzyme preparation from spinach leaves is almost completely inhibited by 8-oxyquinoline or sodium diethyldithiocarbamate, and slightly affected by α,α′-dipyridyl. Benzene oxidation by enzyme preparation is significantly stimulated by NADH and NADPH; in their presence, the benzene hydroxylation product, phenol, is formed in a determinable amount. It is supposed that the enzyme performing the first step of oxidative transformation of benzene in plant leaves contains copper as the prosthetic group.