Detoxication Mechanism of Exogenous Monatomic Phenols in Pea Seedlings

The conversion of exogenous monatomic phenols (O-[1-14C]nitrophenol, 2,4-[1-14C]dinitrophenol, and α–[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. The part of exogenous monatomic phenols is irreversibly bound to proteins via quinone–protein interaction. The amino acid content of the peptides involved in the conjugation process has been established. Penetration into the plant of monatomic exogenous phenols with a high dissociation constant leads to the stimulation of peptide formation.