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

The effects of zinc (Zn) on the physiology of spinach (Spinacia oleracea L.) were investigated in a pot experiment with increasing Zn contents in the horticultural substrate (0, 75, 150, and 300 mg Zn kg-1). Interactions among nutrients in the substrate solution affected plant vitality, biomass yield, and nutrient content in plants. The water-soluble Zn fraction increased with the Zn dose, rising from 0.26 mg kg-1 in the Control to 0.98 mg kg-1 in the Zn300 treatment. The most pronounced effects of elevated Zn content were observed for Ca, Mg, and Mn. In spinach, the dual role of Zn was evident through its impact on yield, particularly regarding aboveground biomass. The positive effects of Zn doses up to 150 mg kg-1 were supported by the tolerance index (TI). In contrast, the 300 mg kg-1 Zn dose exhibited toxic effects, resulting in a 33.3% decrease in the yield of aboveground biomass and a TI value of 0.7. The effects of Zn on nutrient content in aboveground biomass varied with the dose, and the relationship between Zn and P, Fe, Mn, Ca, and K content confirmed a correlation. The toxic effect of the Zn300 treatment was evidenced by a decrease in Ca, Cu, and Fe contents. Additionally, the results of the Zn300 treatment indicated a negative effect on the synthesis of photosynthetic pigments and photosynthesis, likely due to induced oxidative stress. The production of oxalic acid also suggested a toxic effect of the highest Zn dose on spinach.

• Keywords
• hormesis, micronutrient, photosynthesis, spinach, stress, toxicity,
• Publication type
• Journal Article 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