Phytoextraction of Cu, Cd, Zn and As in four shrubs and trees growing on soil contaminated with mining waste

A rapid and specific fluorescent probe based on ESIPT-AIE-active for copper ion quantitative detection in food and environmental samples

In the field of food safety, the identification and measurement of active components in food is a pressing issue. The concentration of copper ions (Cu2+) in the environment is closely linked to food safety, and overall biological health. Therefore, developing rapid and accurate analytical techniques to monitor Cu2+ in food is of great significance. In this study, two fluorescent probes L-2 and L-3 were synthesized through a simple Schiff base condensation reaction. And L-3 demonstrated better anti-interference ability to Cu2+ than that of L-2. Meanwhile, spectroscopic experiments showed that L-3 possessed an extremely low detection limit (LOD) and low limits of quantification (LOQ) (LOD = 92.79 nM, LOQ = 309.33 nM), and quickly respond time (<30 s). Probe L-3 for monitoring effectively quantitatively identified Cu2+ in food and environmental samples, achieving an accuracy rate ranging from 84.42% to 117.45% and precision with a relative standard deviation (RSD) of less than 6.0%. The accuracy had been validated using the inductively coupled plasma-mass spectrometry (ICP-MS). Simultaneously, a WeChat Mini Program has been developed to detect total copper content in food samples based on fluorescence values, enabling consumers to evaluate food safety more intuitively. Moreover, L-3 also facilitated the quantitative visualization of Cu2+ in biological systems, underscoring its compatibility and practicality.

Enhancing Cd and Pb tolerance of Robinia pseudoacacia (black locust) by regulating antioxidant defense system, macroelement uptake and microstructure

Woody plants have received considerable attention for the phytoremediation of heavy metal-contaminated soil. This study aimed to investigate the changes in antioxidant enzyme activity, macroelement uptake and microstructure of the woody plant Robinia pseudoacacia (black locust) for the phytoremediation of cadmium (Cd) and lead (Pb) co-contaminated soil based on dynamic sampling. The results show that black locust demonstrates strong tolerance in Cd and Pb co-contaminated soil. After 30-120 days of cultivation, the activities of superoxide dismutase, peroxidase and the macroelement (potassium [K] and calcium [Ca]) content in plant leaves significantly declined in response to Cd and Pb. However, after 160 d of cultivation, the antioxidant enzyme activities, chlorophyll, sulfhydryl and soluble protein contents, as well as Ca and magnesium content in plant leaves were returned to normal levels under the 40 mg kg-1 Cd and 1000 mg kg-1 Pb contaminated soil (CdPb3). Meanwhile, K content in plant leaves under the CdPb3 treatment was significantly (P < 0.05) increased by 68.9% compared with the control. Cadmium and Pb were primarily accumulated in black locust roots. Scanning electron microscope analysis indicated that the sieve tubes in the roots and stems of plant might block the transport of Cd and Pb. Transmission electron microscope analysis indicated that the number and volume of osmiophilic particles in plant leaves were increased and the cell walls were thickened in response to Cd and Pb stress. Path analysis further indicated that the growth of plant was related to macroelements uptake and physiological change (photosynthesis, antioxidant enzyme activity and chelation). Thus, black locust could effectively regulate the antioxidant defense system, macroelement absorption and microstructure to enhance plant tolerance to Cd and Pb stress. Moreover, black locust could maintain the normal urease, acid phosphatase and sucrase activities in the Cd and Pb co-contaminated soil. These findings suggest that black locust could be considered as a useful woody plant for the phytostabilization in Cd- and Pb-contaminated soil.

Nitrogen and Phosphorus Co-Fertilization Affects Pinus yunnanensis Seedling Distribution of Non-Structural Carbohydrates in Different Organs After Coppicing

The effects of nutritional additions on the non-structural carbohydrates (NSCs) of Pinus yunnanensis Franch. following coppicing were examined in this work. Three levels of phosphorous (P) addition, namely P0 (0 g/plant), P (2 g/plant), and P+ (4 g/plant), and two levels of nitrogen (N) additions, namely N0 (0 g/plant) and N+ (0.6 g/plant) The treatments consisted of D1 (N0P), D2 (N+P0), D3 (N0P), D4 (N+P), D5 (N0P), and D6 (N+P+), utilizing an orthogonal design to assess how these nutrients influence NSC levels and their components throughout many plant organs in P. yunnanensis. The findings showed that fertilization enhanced NSCs and their components' contents in P. yunnanensis. P treatment greatly raised NSC levels in sprouts as well as starch (ST) content in stems and sprouts. N treatment greatly raised soluble sugar (SS) and NSC content in stems and greatly accelerated the contents of NSCs and their components in sprouts. The combined application of N and P further improved SS content in stems. Fertilization effects varied over time, with significant increases in NSC content observed at different stages: at 0 d, fertilization significantly raised NSCs and their components in needles; at 90 d, roots and stems showed increases in both NSCs and their components' contents; at 180 d, stem ST content significantly increased; and at 270 d, NSCs and their components' contents across all organs were significantly increased. Especially in roots, stems, and sprouts, the combined N (0.6 g/plant) and P (2.0 g/plant) treatment (D4) produced the highest NSC concentration among the treatments. This suggested that NSC formation in plants might be greatly promoted by a balanced N and P fertilization ratio acting in concert. Moreover, fertilizer, as part of a general management plan, has long-term and significant benefits on plant development, especially after coppicing, accelerating recovery, expanding growth potential, and thereby strengthening the plant's capacity to adapt to environmental changes.

Strategies of physiological, morpho-anatomical and biochemical adaptation in seedlings of native species exposed to mining waste

Seeds of four native species of trees and shrubs (Larrea cuneifolia, Bulnesia retama, Plectrocarpa tetracantha and Prosopis flexuosa) were exposed to soil contaminated with As, Cu, Cd, and Zn from an abandoned gold mine to identify adaptation strategies. Several physiological, morpho-anatomical, and biochemical parameters were determined. The seed germination of L. cuneifolia, B. retama, and P. tetracantha was fully inhibited in 100 % contaminated soil. Toxicological endpoints as NOEC, LOEC and IC50 ranged from 10 % to 25 % of soil contaminated with mining waste. Radicle elongation was the most sensitive variable to high metal(loid) concentrations, except for L. cuneifolia that hypocotyl elongation was the most affected parameter. P. flexuosa was selected to evaluate biochemical biomarkers and morpho-anatomical parameters. It showed an increase in radicle diameter and central radicle cylinder. A concentration-dependent increase in the O2·- production was observed in radicle and cotyledon. A peak of the enzymatic activity of guaiacol peroxidase, ascorbate peroxidase and catalase enzymes in P. flexuosa seedlings showed a negative relationship between metal(loid) concentration and exposure time. After a drop in the enzymatic activity, an increase in the malondialdehyde content (lipid peroxidation) was observed. The tested native species could be useful for phytoremediation of soils with a very high degree of metal contamination. A further investigation should focus on strategies to improve soil physicochemical characteristics for plant survival at highest contamination levels.

The efficient applications of native flora for phytorestoration of mine tailings: a pan-global survey

Mine tailings are the discarded materials resulting from mining processes after minerals have been extracted. They consist of leftover mineral fragments, excavated land masses, and disrupted ecosystems. The uncontrolled handling or discharge of tailings from abandoned mine lands (AMLs) poses a threat to the surrounding environment. Numerous untreated mine tailings have been abandoned globally, necessitating immediate reclamation and restoration efforts. The limited feasibility of conventional reclamation methods, such as cost and acceptability, presents challenges in reclaiming tailings around AMLs. This study focuses on phytorestoration as a sustainable method for treating mine tailings. Phytorestoration utilizes existing native plants on the mine sites while applying advanced principles of environmental biotechnology. These approaches can remediate toxic elements and simultaneously improve soil quality. The current study provides a global overview of phytorestoration methods, emphasizing the specifics of mine tailings and the research on native plant species to enhance restoration ecosystem services.

Assessment of heavy metals bioaccumulation in Silver Birch (Betula pendula Roth) from an AMD active, abandoned gold mine waste

Acid mine drainage (AMD) is generally outlined as one of the largest environmental concerns, characterized by very low pH value of mine waste, heavy metals and high sulphate content. This extremely hostile environment reduces plant ability to develop and grow. Present study focuses on a silver birch (Betula pendula Roth), a pioneer species that grows on an extremely hostile gold mine waste, to investigate the bioaccumulation of rare metals (thallium (Tl) and indium (In)), as well as nine other more common heavy metals (bismuth (Bi), cadmium (Cd), cobalt (Co), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni), silver (Ag) and zinc (Zn)), and to asses phytoextraction and phytostabilization potential of silver birch. Additionally, parameters determining AMD process and overall contamination (pH, electrical conductivity (EC), sulphates (SO42-), arsenic (As), iron (Fe), oxidation-reduction potential (ORP), turbidity, dissolved oxygen (DO), total dissolved solids (TDS), acidity, hardness, X-ray diffraction (XRD) and radioactivity) were determined in mine waste and drainage water samples. To assess the heavy metals bioaccumulation and mine waste status, statistical geochemical indices were determined: bioaccumulation factor (BCF), pollution load index (PLI), geochemical abundance index (GAI) and exposure index (EI). The results show that silver birch bioaccumulates the essential elements Cu, Ni, Mn and Zn, and the nonessential elements Tl (average BCF = 24.99), In (average BC = 23.01) and Pb (average BCF = 0.84). Investigated mine waste was enriched by Bi, Ag and Cd according to positive values of GAI index. Present research provides a novel insight into bioaccumulation of nonessential heavy metals in silver birches who grow on the extremely hostile mine waste, and they exhibit significant phytoremediation potential.