2,7-Diaminofluorene is a sensitive substrate for detection and characterization of plant root peroxidase activities

The 2,7-diaminofluorene (DAF) was a far more sensitive substrate for lucerne root peroxidases than were guaiacol or pyrogallol. All the peroxidase assays had an optimum pH of 6. The optimum temperature for the activity of DAF-peroxidase was 35 degreesC, far lower than those of guaiacol- and pyrogallol-peroxidases (60 degreesC). Electrophoresis of lucerne root peroxidases revealed the presence of eight isoenzymes using DAF as substrate. and only two with guaiacol. The influence of four organic solvents on peroxidase activity was also assessed. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.