Induction of hypericins in Hypericum perforatum in response to chromium

Seedlings of Hypericum perforatum were grown with 0.01 and 0.1 mM of chromium added to the nutrient media. A treatment with 0.01 mM Cr(VI) for seven days resulted in an increased production of protopseudohypericin (+ 135%), hypericin (+ 38%) and pseudohypericin (+ 5%). Treatment with 0.1 mM Cr(VI) for two days also caused an increase of protopseudohypericin (+ 167%), hypericin (25%) and pseudohypericin (+ 5%). The greatest effect of chromium treatment was observed at a concentration of 0.1 mM for seven days: protopseudohypericin increased + 404% and pseudohypericin to + 379%. Hypericin was not affected by this treatment.