This study investigated the metabolic adaptive responses to As contamination and As co-contamination with cadmium, lead, and zinc in the leaves and tubers of cherry radish (Raphanus sativus var. sativus Pers.). The response was assessed by measuring malondialdehyde levels, total phenolic content (TPC), total anthocyanin pigment (TAC), growth and stress phytohormone concentration, and free amino acid content. The characteristic As accumulation of single contamination resulted in a decrease in tuber growth. However, in the case of co-contamination, As uptake was influenced by the presence of other potentially toxic elements (PTEs), mainly zinc, with no significant effect on growth. Both contaminated treatments exhibited significant differences in metabolite levels among the organs, along with notable changes in their contents. Increases in malondialdehyde, TPC, and TAC indicated induced oxidative stress and an antioxidant response that was more pronounced by As co-contamination. Also, the results for phytohormones, which showed both increases and decreases, along with selected free amino acids (which showed increases), demonstrated a more significant influence of As co-contamination. Based on these findings, it can be concluded that the response of cherry radish to contaminated treatments exhibited significant differences in the studied parameters, along with variability in the results, reflecting the extent of the effects of PTEs that induce oxidative stress.

• Keywords
• amino acids, hormones, metalloid, stress, vegetable,
• MeSH
• Amino Acids * metabolism   MeSH
• Arsenic * toxicity   MeSH
• Soil Pollutants toxicity   MeSH
• Plant Leaves metabolism   drug effects   MeSH
• Malondialdehyde metabolism   MeSH
• Oxidative Stress drug effects   MeSH
• Raphanus * metabolism   drug effects   growth & development   MeSH
• Plant Growth Regulators * metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Amino Acids * MeSH
• Arsenic * MeSH
• Soil Pollutants MeSH
• Malondialdehyde MeSH
• Plant Growth Regulators * MeSH

Many contaminated soils contain several toxic elements (TEs) in elevated contents, and plant-TE interactions can differ from single TE contamination. Therefore, this study investigated the impact of combined contamination (As, Cd, Pb, Zn) on the physiological and metabolic processes of lettuce. After 45 days of exposure, TE excess in soil resulted in the inhibition of root and leaf biomass by 40 and 48%, respectively. Oxidative stress by TE accumulation was indicated by markers-malondialdehyde and 5-methylcytosine-and visible symptoms of toxicity (leaf chlorosis, root browning) and morpho-anatomical changes, which were related to the change in water regime (water potential decrease). An analysis of free amino acids (AAs) indicated that TEs disturbed N and C metabolism, especially in leaves, increasing the total content of free AAs and their families. Stress-induced senescence by TEs suggested changes in gas exchange parameters (increase in transpiration rate, stomatal conductance, and intercellular CO2 concentration), photosynthetic pigments (decrease in chlorophylls and carotenoids), a decrease in water use efficiency, and the maximum quantum yield of photosystem II. These results confirmed that the toxicity of combined contamination significantly affected the processes of lettuce by damaging the antioxidant system and expressing higher leaf sensitivity to TE multicontamination.

• Keywords
• anthropogenic contamination, bioaccumulation, metals/metalloids, nitrogen metabolism, oxidative stress, stress response,
• Publication type
• Journal Article MeSH

A pot experiment was undertaken to investigate the effect of Cd, Pb and Zn multi-contamination on the physiological and metabolic response of carrot (Daucus carota L.) after 98 days of growth under greenhouse conditions. Multi-contamination had a higher negative influence on leaves (the highest Cd and Zn accumulation) compared to the roots, which showed no visible change in terms of anatomy and morphology. The results showed the following: (i) significantly higher accumulation of Cd, Zn, and Pb in the multi-contaminated variant (Multi) compared to the control; (ii) significant metabolic responses-an increase in the malondialdehyde content of the Multi variant compared to the control in the roots (by 20%), as well as in the leaves (by 53%); carotenoid content in roots decreased by 31% in the Multi variant compared with the control; and changes in free amino acids, especially those related to plant stress responses. The determination of hydroxyproline and sarcosine may reflect the higher sensitivity of carrot leaves to multi-contamination in comparison to roots. A similar trend was observed for the content of free methionine (significant increase of 31% only in leaves); (iii) physiological responses (significant decreases in biomass, changes in gas-exchange parameters and chlorophyll a); and (iv) significant changes in enzymatic activities (chitinase, alanine aminopeptidase, acid phosphatase) in the root zone.

• Keywords
• cadmium, free amino acids, lead, malondialdehyde, photosynthesis, root vegetable, soil enzymes, zinc,
• MeSH
• Chlorophyll A metabolism   MeSH
• Cadmium * metabolism   MeSH
• Daucus carota * metabolism   MeSH
• Lead metabolism   MeSH
• Soil MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Chlorophyll A MeSH
• Cadmium * MeSH
• Lead MeSH
• Soil MeSH

The effect of toxic element multicontamination on photosynthetic responses was observed in a greenhouse hydroponic culture of lettuce plants (Lactuca sativa var. capitata). The experiment focused only on the combined effect of selected toxic elements without the influence of soil, due to the hydroponic conditions. Pre-cultivated (six-true-leaf stage) plants were grown in control and contaminated hydroponic culture for 14 d. The mix of toxic elements (As, Cd, Pb, and Zn) in the contaminated solution corresponded to the water-soluble fraction of soil from the anthropogenically contaminated Litavka River area, Czech Republic. The plant response was measured by determining the toxic element contents, dry biomass, and gas-exchange parameters. Lettuce accumulated toxic elements predominantly in the roots, with low translocation to the leaves. The uptake of toxic elements harmed photosynthesis and caused a decrease in net photosynthetic rate, transpiration rate, and stomatal conductance. Consequently, the whole dry biomass of the plants decreased. The results show that contamination in hydroponic conditions had an irreversible effect on plant fitness due to direct contact between the roots and contaminated solutions.

• Keywords
• solution, stress, toxic element, translocation factor, transpiration rate,
• Publication type
• Journal Article MeSH

Three garden vegetables-radish, carrot and lettuce-were cultivated in a pot experiment using two soils from the Příbram area polluted mainly by cadmium (Cd), zinc (Zn), lead (Pb) and chromium (Cr). The soils of the Příbram district, Czech Republic, are heavily polluted as a result of the atmospheric deposition of toxic elements originating from historic lead-silver mining and smelting activities. The results showed that lettuce absorbed the highest amounts of toxic elements (Cd 28 and 30, Cr 12 and 13, Zn 92 and 205 mg·kg-1 DW), except Pb, which was higher in radish (30 and 49 mg·kg-1 DW). Changes in macronutrient contents in edible parts were not found, except for sulfur. A higher total free amino acids (fAAs) accumulation was shown in all vegetables in more contaminated soil, with the highest fAA content being in radish. A group of essential fAAs reached 7-24% of total fAAs in vegetables. The risk to human health was characterized using the target hazard quotient and total hazard index (HI). The cumulative effect of the consumption of vegetables with HI > 1 showed possible non-carcinogenic health effects for lettuce and carrot. HI decreased in the order Cd > Pb > Cr > Zn. The carcinogenic risk of toxic elements decreased in the order Cd > Cr > Pb (0.00054, 0.00026, 0.00003). These values showed a carcinogenic risk from the consumption of lettuce and carrot and confirmed that the adult population of the studied area is at high risk if lettuce and carrot cultivated in this area are consumed daily.

• Keywords
• Daucus carota, Lactuca sativa, Rapahanus sativus, cadmium, carcinogenic risk, lead, target hazard quotient, toxic elements, zinc,
• Publication type
• Journal Article MeSH