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.).

Changes in Rosmarinic Acid Accumulation and Rosmarinic Acid Synthase Gene Expression in Thymus vulgaris L. Influenced by Phenology and Environmental Factors

“…The effect of a water shortage on the elevation of the RA content is more pronounced in warmer conditions. Previous studies demonstrated variable results regarding this topic (Németh-Zámbori et al, 2017). A short-term heat treatment (38°C for 5 h) elevated the RA content of Melissa officinalis L. (Pistelli et al, 2019).…”

“…Lamiaceae species react due to a significant elevation of the RA content stemming from a lack of water (Manukyan, 2011;Németh-Zámbori et al, 2017). The effects of a water shortage on RAS gene expression and RA content outcomes in intact Thymus vulgaris plants have not yet been studied.…”

“…Several studies have presented the effects of environmental factors on the production of secondary metabolites (Bettaieb et al, 2011;Manukyan, 2011;Gharibi et al, 2019). The water supply may influence the accumulation of polyphenols, including that of RA, and the effect is species-specific (Németh-Zámbori et al, 2017). Temperature also greatly affects the production of secondary metabolites.…”

Inducing the Production of Secondary Metabolites by Foliar Application of Methyl Jasmonate in Peppermint

“…It has been established that dry conditions stimulate their production. According to several reports, the total phenolic content (TPC) of peppermint samples seems to increase significantly in stressed plants [ 11 , 12 , 14 , 15 ]. Moreover, the ratio of the major phenolic compounds seems to increase remarkably, (such as rosmarinic acid and rutin compounds) [ 16 ].…”