Radioactivity level in relation to geological substrate: dynamics of natural and artificial radionuclides on Teucrium montanum L. (Lamiaceae) habitats.

There are no results of comparative ecological studies of the radionuclide activity concentration in the plants and soil in relation to geological substrate. Presented research encompasses the comparative analysis of the concentration of four radionuclides, three natural (40K, 226Ra, 232Th) and one artificial (137Cs) in soil samples and aerial plant parts of Teucrium montanum from different natural habitats on serpentinite and calcareous geological substrate. The activity concentrations of radionuclides were measured with high purity germanium (HPGe) detector and expressed as Bq kg-1. The calculated activity concentrations of 40K, 226Ra, 232Th, and 137Cs in soil samples from serpentinite/calcareous habitats are in range 39.6-91.0/59.3-1018.8, 1.7-5.5/4.3-52.4, 2.4-10.9/5.9-72.9, and 57.2-844.9/29.6-701.5 Bq kg-1, respectively. The activity concentrations of 40K, 226Ra, 232Th, and 137Cs in plant samples are in range 152.9-445.9/228.0-521.4, n.d.-1.2/0.6-5.6, n.d./0.2-0.9, and 1.0-46.4/1.7-7.0 Bq kg-1, respectively. The obtained results showed that the quantities of 137Cs are greater in the soil and plant material from the serpentinite habitats, while quantities of 40K, 226Ra, and 232Th are greater in the soil and plant material from calcareous habitats. In general, the level of radioactivity in plants and soil depends on the type of the geological substrate. The content of radionuclides in plants is correlated with the radionuclide content in the soil. In addition to other specifics in physical and chemical properties, serpentinite habitats are characterized by an increased amount of Cs in the soil, which causes an increased amount of this radionuclide in plants such as Teucrium montanum.

Effects of calcareous and serpentinite parent material on the mineral characteristics of soils and plant material of Teucrium montanum L. (Lamiaceae).

The objective of this study was to determine eco-edaphic characteristics and influence of different substrates on mineral characteristics of facultative serpentinophyte. The total concentration of 20 elements Al, As, B, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Se, and Zn in soil samples and aboveground parts of medicinal plant species Teucrium montanum from various calcareous and serpentinite habitats in the territory of Serbia was determined. The concentration of the elements was established by inductively coupled plasma optical emission spectrometry-ICP-OES. The obtained results showed that the quantities of certain elements Al, As, B, Ca, Cd, Cu, K, Li, P, Se, and Zn were detected more in the soil samples from calcareous habitats in comparison to the quantities of other metals Co, Cr, Fe, Mg, Mn, Na, Ni, which were more frequently found in the soil samples from the serpentinite habitats. Analyzed plant samples from calcareous habitats contained higher concentrations of Al, Ca, Li, and Zn as opposed to serpentinite containing higher concentrations of Co, Cr, Fe, Mg, Mn, Na, Ni, and Se. Examined species can accumulate macro- and microelements in different quantities, depending on the substrate type. Differences in the concentration of certain elements in the soil samples and aboveground parts of the T. montanum from calcareous and serpentinite habitats indicate significant phenotypic plasticity of the investigated species as well as the existence of specific serpentinite ecotypes developed by the activity of various edaphic factors.

Variability of Secondary Metabolites of the Species Cichorium intybus L. from Different Habitats.

The principal aim of this paper is to show the influence of soil characteristics on the quantitative variability of secondary metabolites. Analysis of phenolic content, flavonoid concentrations, and the antioxidant activity was performed using the ethanol and ethyl acetate plant extracts of the species Cichorium intybus L. (Asteraceae). The samples were collected from one saline habitat and two non-saline habitats. The values of phenolic content from the samples taken from the saline habitat ranged from 119.83 to 120.83 mg GA/g and from non-saline habitats from 92.44 to 115.10 mg GA/g. The amount of flavonoids in the samples from the saline locality varied between 144.36 and 317.62 mg Ru/g and from non-saline localities between 86.03 and 273.07 mg Ru/g. The IC50 values of antioxidant activity in the samples from the saline habitat ranged from 87.64 to 117.73 µg/mL and from 101.44 to 125.76 µg/mL in the samples from non-saline habitats. The results confirmed that soil types represent a significant influence on the quantitative content of secondary metabolites. The greatest concentrations of phenols and flavonoids and the highest level of antioxidant activity were found in the samples from saline soil. This further corroborates the importance of saline soil as an ecological factor, as it is proven to give rise to increased biosynthesis of secondary metabolites and related antioxidant activity.

Secondary metabolites and metal content dynamics in Teucrium montanum L. and Teucrium chamaedrys L. from habitats with serpentine and calcareous substrate.

The purpose of this comparative analysis is the determination of the total quantity of metals (Mg, Ca, K, Ni, Fe, Mn, Zn, Cu, Cr and Pb) in soil samples, above ground plant parts and tea made of plants Teucrium montanum and T. chamaedrys from different serpentine and calcareous habitats as well as of the total quantity of phenolic compounds and antioxidant activity. The obtained results showed that the quantities of certain metals (Mg, Fe, Ni and Mn) in the soil from the serpentine habitats were greater in comparison with other metals (Ca, Zn and Pb) which were more frequently found in the soil from the calcareous habitats. The results demonstrated that the analysed plant samples from the serpentine habitats contained higher quantity of Fe, Ni and Cr as opposed to the plant samples from the calcareous habitats which contained greater quantity of Ca and Zn. Although the studied species accumulate analysed metals in different quantities, depending on the substrate type, they are not hyperaccumulators of these metals. The use of these species from serpentine habitats for tea preparation is safe to a great extent, because in spite of the determined metal absorption by plant organs, the tea does not contain dangerous quantity of heavy metals. The results showed greater total quantity of phenolic compounds and the higher level of antioxidant activity in the plant samples from serpentine habitats in comparison with the samples from calcareous habitats, which is an indicator of one of the mechanisms of adaptation to the serpentine habitat conditions.