Peroxidase in variant cell lines of Haplopappus gracilis

A comparative study on growth characteristics, phenolic content, protein content and peroxidase activity revealed differences between a wild type cell suspension culture of Haplopappus gracilis and three cell lines, varying in nitrogen metabolism. The variant cell lines showed enhanced growth and protein when compared to the wild type but reduced peroxidase activity, peroxidase isoenzyme polymorphism and phenolic content. Peroxidase activity and growth of Haplopappus cells were inversely related. Furthermore, the data indicated that peroxidase activity and phenolic content are not causally related and that the peroxidase is not involved in cell aggregation by polymerization of phenols. On the other hand, peroxidase probably oxidizes phenols to polymeric substances, causing browning during senescence.