Differential effects of light and nitrogen on production of hypericins and leaf glands in Hypericum perforatum

摘要: Abstract The effect of light intensity and root nitrogen supply on the levels leaf hypericins was examined for St. John’s wort ( Hypericum perforatum L.) grown in a sand culture system with artificial lighting. Increasing illuminating plants from 106 to 402 μmol·m –2 ·s –1 resulted continuous increase level hypericins. Using dissection approach, association dark glands leaves shown, it found that increasing parallel number glands. In this respect, linear relationship observed between gland R  = 0.901). While decrease also yielded an hypericins, response occurred discontinuous manner over range tested no significant upon observed. Overall, these effects increased decreased appear be independent additive, may reflect differences sites processes where environmental parameters impact production phytochemicals.