PSX-B-25 Milk productivity and zinc species analysis in cattle depending on the level of lead accumulation

The aim was to study the milk productivity and zinc species in dairy Holstein cow blood serum depending on the level of lead accumulation. Fat and protein content in milk was assessed by the FIL-IDF procedure. The major zinc species in dairy cow blood serum were tested using a hybrid high-performance liquid chromatography-inductively coupled plasma-mass spectrometry technique. The lead content in the blood serum of all animals was in the intervals of the physiological standard. Animals with low-normal values (Pb concentration up to the 25th percentile) and high-normal values (Pb concentration above the 75th percentile) were taken to form comparison groups. Animals with high-normal values of lead had a statistically significant decrease of milk yield by 21.8% and daily production of fat by 16.4%. There was a tendency towards a decrease in the yield of protein and its percentage. It was found that the zinc content in all studied fractions (α 2-macro-globulin tetramer, α 2-macro-globulin dimer, albumin, citrates, total content) was statistically significantly lower (more than 4.8 times) in the group with high-normal values of lead. The change in the redistribution of zinc-binding ligands was found depending on the level of lead in the blood. The relative content of the α2-macro-globulin tetramer and α2-macro-globulin dimer was significantly higher by 7% and by 13% in the group with high-normal values of lead. There was the decrease in the level of animal productivity, the metal-ligand forms of zinc underwent changes despite the absence of a significant difference in the total level of lead in the blood serum. This indicates a high potential for the use of speciation analysis in the laboratory diagnosis and allows predicting and correcting zinc metabolism. The studies were performed in accordance with the research plan for 2019–2021 of the Federal Research Center of Biological Systems and Agrotechnologies RAS No. 0526-2019-0001.

Accumulation and distribution of lead (Pb) in different tissues of Lucky bamboo plants (Dracaena sanderiana)

Lucky bamboo plants (Dracaena sanderiana) were used to study the accumulation and distribution of lead (Pb) in tissues of root, stem and leaf, as well as the impact of lead accumulation on the anatomical structure of these tissues. Dracaena sanderiana plants were exposed to Pb(NO3)2 solution at the Pb concentrations of 0; 200; 400; 600; 800; 1,000; 2,000; 3,000 and 4,000 mg/L for 60 days. The results showed that the more the Pb concentration was used, the more the amount of lead was accumulated and deposited. The tolerance limit of Dracaena sanderiana was 800 mg/L of Pb in water. The lethal concentration for plants was 4,000 mg/L Pb. When the concentrations of Pb in the solution were higher than the tolerance limit of the plant, the growth of Dracaena sanderiana could be inhibited. Dracaena sanderiana could accumulate up to 39,235 mg/kg Pb in the presence of Pb at 800 mg/L. Lead was accumulated mainly in roots (97.5%) and deposited mainly in the cell walls and the spaces between cells in tissues of roots. In the stems and leaves of Dracaena sanderiana, lead accumulation was limited and distributed mainly around vascular bundles. Lead accumulation caused changes in the anatomical structure of root, stem and leaf tissues. The accumulation and distribution of Pb is mainly in the cell walls and the space of cells; it could be a detoxification

Biochar and alternate partial root-zone irrigation greatly enhance the effectiveness of mulberry in remediating lead-contaminated soils

Aims Soil lead contamination has become increasingly serious and phytoremediation can provide an effective way to reclaim the contaminated soils. This study aims to examine the growth, lead resistance and lead accumulation of mulberry (Morus alba L.) seedlings at four levels of soil lead contamination with or without biochar addition under normal or alternative partial root-zone irrigation (APRI). Methods We conducted a three-factor greenhouse experiment with biochar (with vs. without biochar addition), irrigation method (APRI vs. normal irrigation) and four levels of soil lead (0, 50, 200 and 800 mg·kg−1). The performance of the seedlings under different treatments was evaluated by measuring growth traits, osmotic substances, antioxidant enzymes and lead accumulation and translocation. Important Findings The results reveal that mulberry had a strong ability to acclimate to soil lead contamination, and that biochar and APRI synergistically increased the biomass and surface area of absorption root across all levels of soil lead. The seedlings were able to resist the severe soil lead contamination (800 mg·kg−1 Pb) by adjusting glutathione metabolism, and enhancing the osmotic and oxidative regulating capacity via increasing proline content and the peroxidase activity. Lead ions in the seedlings were primarily concentrated in roots and exhibited a dose–effect associated with the lead concentration in the soil. Pb, biochar and ARPI interactively affected Pb concentrations in leaves and roots, translocation factor and bioconcentration. Our results suggest that planting mulberry trees in combination with biochar addition and APRI can be used to effectively remediate lead-contaminated soils.