Acta Scientiarum Polonorum: Hortorum Cultus (Aug 2017)
VARIABILITY OF PHENOLIC COMPOUNDS OF FOUR AROMATIC Lamiaceae SPECIES IN CONSEQUENCE OF DIFFERENT WATER SUPPLY
Abstract
The reactions of lemon balm, marjoram, peppermint, thyme were investigated and compared in a pot experiment, adjusting 70% and 40% of soil water capacity (SWC). Biomass, total phenolic content (TPC), rosmarinic acid content (RA) and antioxidant capacity (FRAP, DPPH) of both the shoots and roots were measured. As an universal phenomenon the water stress (40% SWC) decreased the total biomass production of all species drastically. The highest increase was observed in the shoot mass of peppermint and lemon balm (decreased from 52.6 g·plant–1 to 11.3 g·plant–1 and from 236.8 g·plant–1 to 58 g·plant–1, respectively). The reaction of marjoram was much more moderate. The accumulation level of TPC was accelerated in the aboveground parts of the studied species, universally. The reactions in the roots were less characteristic. The largest increase of TPC was measured in the shoots of lemon balm (from 359.015 mg GAE· g–1 d.w. up to 412.44 GAE·g–1 d.w.). The reaction of marjoram was the less characteristic in this respect, as well. The parallel changes of biomass and TPC level might allow the total phenolic content to function as an adequate marker in predicting the lack of appropriate water supply. RA content showed species characteristics. Thyme, marjoram and peppermint reacted by a significant elevation (by 23–127%) of the RA content to the lack of water. The highest proportions were accumulated in shoots of the stressed thyme plants (3.45% d.w.).
