ISHS Acta Horticulturae 629: XXVI International Horticultural Congress: The Future for Medicinal and Aromatic Plants
ROLE OF INDOLEAMINES IN REGULATION OF MORPHOGENESIS IN IN VITRO CULTURES OF ST. JOHN'S WORT (HYPERICUM PERFORATUM L.) |
| Authors: | S.J. Murch, P.K. Saxena |
| Keywords: | Medicinal plant, melatonin, shoot organogenesis, serotonin, thidiazuron |
| Abstract:
The presence of indoleamines and their potential role in morphogenesis in vitro was investigated in axenic cultures of St. John’s wort (Hypericum perforatum L. New Stem). De novo shoot regeneration was induced on etiolated hypocotyl explants after 9 days of exposure to thidiazuron (5 µmol/L). Melatonin, a tryptophan-derived mammalian neurohormone was quantified in leaf, flower, stem, and etiolated hypocotyls. Radiolabel from 14C-tryptophan was recovered as 14C-melatonin in sterile plantlets indicating endogenous synthesis of this compound in St. John’s wort. Application of inhibitors of mammalian neuro-processes including: p-chlorophenylalanine, d-amphetamine, Prozac™, Ritalin™ and hydralazine modulated regeneration and levels of endogenous auxin and indoleamines. Although there is no known role for melatonin in plant tissues, these data provide an indication that the balance of the endogenous concentrations of serotonin and melatonin may play a role in in vitro plant morphogenesis. | |
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