Detoxication mechanism of exogenous monatomic phenols in pea seedlings.

The conversion of exogenous monatomic phenols (O-[1-(14)C]nitrophenol, 2,4-[1-14C]dinitrophenol, and alpha-[1-14C]naphthol) in pea seedlings has been investigated. It has been found that in the pea seedlings glycosylation of these phenols does not occur, but the main pathway of their detoxication is conjugation with the low-molecular-weight peptides. Approximately 80% of phenols absorbed by seedlings form phenol-peptide conjugates.

[Intracellular localization and characteristics of monophenol monooxygenase in the leaves of tea plants].

The intracellular localization and some properties of monophenol monooxygenase (MPMO) from fresh tea leaves have been studied. It has been demonstrated that MPMO activity is located in cytosole and chloroplasts. These two forms have different properties.

Organic toxicants and plants.

Organic xenobiotics absorbed by roots and leaves of higher plants are translocated by different physiological mechanisms. The following pathways of xenobiotic detoxication have been observed in higher plants: conjugation with such endogenous compounds as peptides, sugars, amino acids, and organic acids; oxidative degradation and consequent oxidation of xenobiotics with the final participation of their carbon atoms in regular cell metabolism. The small parts of xenobiotics are excreted maintaining their original structure and configuration.

[Comparative study of soluble and immobilized phenol oxidase from the fungus Mycelia sterilia IBR 35219/2].

Phenol oxidase (EC 1.14.18.

Detoxication of phenol in annual plant seedlings.

Transformation of phenol (14C6H5OH) penetrating through the roots of mung bean (Phaseolus aureus) and wheat (Triticum vulgare) sterile seedlings has been studied. Phenol was coupled to low-molecular-weight peptides, producing phenol-peptide conjugates. Hydrolytic cleavage of the conjugates liberated initial labeled phenol and some unlabeled amino acids.

Effect of low-molecular-weight alkanes on the plant cell photosynthetic apparatus.

The effects of aliphatic hydrocarbons--methane, ethane, propane, butane, and their mixture--on the photosynthetic apparatus of maize (Zea mays) and raygrass (Arrhenetherum elatius) leaves have been studied. The pathology of subcellular organelles as well as of the whole architectonics of the cell was observed. An especially destructive action of alkanes is expressed on the granalamellae system of chloroplasts.

Uptake and transformation of benzene and toluene by plant leaves.

The [1-6(14)C]benzene and [1-(14)C]toluene vapors penetrate into hypostomatous leaves of Acer campestre, Malus domestica, and Vitis vinifera from 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.

Plant monooxygenases: participation in xenobiotic oxidation.

The induction of individual components of the plant microsomal monooxygenase system have been studied. Quantitative distribution of NADPH reducible equivalents at monooxygenase and oxidase reactions and rereduction of coenzyme have been exhibited when there is deficiency of oxygen. Xenobiotic oxidation specificity in NADPH and NADH synergism with NADPH have been detected.