The effects of different harvest periods on the consolidation of tropan alkaloids and phenolic compounds in the root cultures of the black henbane (Hyoscyamus niger)

This study was carried out to determine the effects of different harvest periods on root growth and secondary metabolite accumulation in adventitious roots obtained from leaf stems of black henbane (Hyoscyamus niger). Fort his aim, adventitious roots cultured in nutrient media containing 1mM methyl jasmonate (MeJA) were harvested in 11 different periods starting from the first day to the 30th day. After harvest, fresh root weights, dry root weights and root growth indexes as root growth attributes and tropane alkaloids and phenolic compounds as secondary metabolites were investigated. As a result of the study, the greatest values of root growth attributes including fresh root weights, dry root weights and root growth indexes were obtained in the roots harvested from the 12th day to the 30th day. While the highest amounts of scopolamine were obtained from the roots harvested on the 15th, 18th and 21st days, the greatest values in terms of the amounts of hyocyamine were determined in the roots harvested on the 12th and 15th days. The greatest total phenolic contents was found in the roots harvested on the 15th day as 19.33 mg/g. In the phenolic analysis made by HPLC, ferulic acid, caffeic acid, o-coumaric acid, p-coumaric acid, rutin and quercetin were not be detected in the roots. On the other hand, it was shown that the amounts of gallic acid, catechin, epicatechin, vanillin, cinnamic acid, rosmarinic acid and chlorogenic acid showed significant changes depending on the harvest dates. As a conclusion, the 15th day was found as the most suitable harvesting date providing the highest values in terms of all the criteria examined in the study, for the adventitious roots applied with 1 mM MeJA in black henbane.