Lignification in Trees: Indication of Exclusive Peroxidase Participation

Syringaldazine did not turn purple on cross sections of tree branches or saplings or on cambial tissue cultures unless hydrogen peroxide was added; this indicated the absence of laccase but presence of peroxidase in lignifying cells. Peroxidase, therefore, apparently is the only enzyme that polymerizes p -coumaryl alcohols to lignin in trees.