Integrated survey on the heavy metal distribution, sources and risk assessment of soil in a commonly developed industrial area.

The Jiangzhe Area was relatively common area that rely on industrial process for rapid development with serious heavy metals contamination. This study investigated the spatial, vertical and speciation distribution, correlation of heavy metals, as well as assessed pollution and health risks in three representative contamination industries at Jingjiang (electroplating site), Taizhou (e-waste recycling site) and Wenzhou (leather production site) in the Jiangzhe Area. The results indicated that the Cr(VI) pollution was serious in all three sites and there was a tendency to gradually decrease with depth. As for other heavy metals, not only the total concentration, but also the addition of acid soluble and reducible speciation generally decreased with soil depth at Jingjiang and Taizhou sites. Significantly positive correlations supported by correlation analysis were detected between the following elements: Cu-Ni (p < 0.01), Cr(VI)-Ni (p < 0.05) and Cr(VI)-Cu (p < 0.05) at Jingjiang site, Cu-Ni (p < 0.01), Cu-Cd (p < 0.01) and Ni-Cd (p < 0.05) at Taizhou site indicating possibly the same sources and pathways of origin, while the significantly negative correlation of Cd-Ni (p < 0.05) at Wenzhou site meaning the different sources. As regards the pollution assessment of topsoil, the mean PI value indicated that Cr(VI) contaminated severe in all three sites. In general, Jingjiang site was severe pollution (4.06), while Taizhou and Wenzhou (2.27 and 2.66) were moderate pollution, as NIPI value shown. In terms of health risk assessment that received much attention, non-carcinogenic risks caused by Pb contamination were significant for children at Jingjiang and Taizhou sites, with the HI values of 3.42E+ 00 and 2.03E+ 00, respectively. Ni caused unacceptable carcinogenic risk for both adults and children at all three sites. The present study can help to better understand the contamination characteristics of heavy metals in the commonly developed industrial area, and thus to control the environmental quality, so as to truly achieve the goal of "Green Deal objectives ".

Cosmopolitan cadmium hyperaccumulator Solanum nigrum: Exploring cadmium uptake, transport and physiological mechanisms of accumulation in different ecotypes as a way of enhancing its hyperaccumulative capacity.

The non-essential element cadmium (Cd) is one of the most problematic priority soil pollutants due to multitude of pollution sources, mobility in the environment and high toxicity to all living organisms. This strongly limits also the number and occurrence of species - Cd hyperaccumulators to be used for soil phytoremediation. However, efficient Cd hyperaccumulator Solanum nigrum L. appeared to commonly occur worldwide as a representative of Solanum nigrum complex of a great taxonomic diversity. This led to the idea that the search among different ecotypes of Solanum nigrum L. may result in the identifying the most efficient Cd hyperaccumulator without applying to soil any additional measures such as chemical ligands. In this first pioneering comparative study, three randomly selected ecotypes of S. nigrum L. ssp. nigrum from Shenyang (SY) and Hanzhong (HZ) in China, and Kyoto (KY) in Japan were used in pot experiments at soil treatments from 0 to 50 mg Cd kg-1. The Cd accumulation capacity appeared to represent KY > HZ > SY range, KY ecotype accumulating up to 73%, and HZ ecotype up to 67% bigger total Cd load than SY ecotype. At Cd content in soil up to 10 mg kg-1, no significant effect on the all ecotype biomass, photosynthetic activities, contents of first line defense antioxidant enzymes (CAT, SOD, GPX), and scavenging antioxidants ASA, GSH, was observed. At Cd in soil>10 mg kg-1all these parameters showed decreasing, and cell damage indicator MDA increasing trend, however total accumulated Cd load further increased up to 30 mg kg Cd in soil in all ecotypes in the same KY > HZ > SY sequence. The study proved the great potential of enhancing Cd accumulation capacity of S. nigrum species by selecting the most efficient ecotypes among commonly occurring representatives of S. nigrum complex worldwide. Moreover, these first comparative experiments convinced that the cosmopolitan character and great variety of species/subspecies belonging to Solanum nigrum complex all over the world opens the new area for successful soil phytoremediation with the use of the most appropriate eco/genotypes of S. nigtum as a tool for the best Cd-contaminated soil management practice.

The effects of different electrode materials on seed germination of Solanum nigrum L. and its Cd accumulation in soil.

The effects of different electrode on Solanum nigrum L. seed germination were determined. The result showed that germination percentage (GP) of seeds in treatment T2 (titanium electrode) was 26.6% higher than in control (CK, without electric field). High potassium and calcium concentrations were beneficial for seed enzymatic activity in treatment T2, which could partly explain the increase in GP. Cd accumulation (µg/pot) in S. nigrum treated with any electric field was significantly higher (p<0.05) than in CK without electric field. Specifically, Cd accumulation under the treatment T3 (stainless steel electrode) was the highest both in roots and shoots; this accumulation in shoots and roots were 74.7 % and 67.4 % higher for stainless steel than in CK. This increase must have been associated with a higher Cd concentration in plants and did not exert a significant effect on the biomass. In particular, Cd concentrations in roots and shoots under stainless steel treatment were both significantly higher than in CK (p<0.05), which had to be related to the higher available Cd concentration in the soil in the middle region. Furthermore, it could be attributed to altered soil pH and other soil properties. Moreover, none of the biomasses were significantly affected (p<0.05) by different electrode materials compared to CK.

The cadmium accumulation differences of two Bidens pilosa L. ecotypes from clean farmlands and the changes of some physiology and biochemistry indices.

Bidens pilosa L. is a widely distributed Cd-hyperaccumulator species in the world with large biomass and fast growth rate. The Cd accumulating differences between different ecotypes of B. pilosa is not clear. This experiment firstly compared the Cd concentrations and relative physio-biochemical indices using two B. pilosa ecotypes collected from clean soils. The results showed that the Cd concentrations of stems and leaves of Hanzhong ecotype of B. pilosa (HZ) and Shenyang ecotype (SY) were all higher than their root Cd concentrations in different Cd concentration gradient experiment (from 2.57 mg kg-1 to 37.17 mg kg-1 in soils). Cd concentrations of the roots, stems and leaves of HZ and SY were all higher than in the soils either. However, HZ accumulated higher Cd concentrations than SY, i.e. roots increased by 32.7-45.8%, stems increased by 32.3-46.6% and leaves increased by 33.4-68.4%, respectively. Furthermore, the biomasses of HZ were all higher than the SY either. Compared to SY, higher Cd accumulation of HZ might be relevant with its higher photosynthetic pigment content, stomatal conductance, intercellular CO2 concentration, some antioxidant enzyme activities, H+-ATPase, Ca2+-ATPase and 5'-AMPase activities, and lower malondialdehyde (MDA) content. Particularly, the changes of extractable Cd concentrations in rhizospheric soils of HZ and SY were corresponding to their Cd concentrations. Considering the two different ecotypes of HZ and SY were all collected from different clean farmlands, the new foundings that different mechanisms of HZ and SY accumulating Cd from the soil might be very important for screening and constructing ideal hyperaccumulator aimed at improving phytoremediation capacities in the future.

The potential of medicinal plant extracts in improving the phytoremediation capacity of Solanum nigrum L. for heavy metal contaminated soil.

This study focused on the effects of eight medicinal plant extracts on Solanum nigrum L. potential to accumulate Cd and Pb from soil. These medicinal plants were common and relatively cheap. The eight 10% water extracts were made from the peel of Citrus reticulata Blanco (PCR), fruit of Phyllanthus emblica L. (FPE), root of Pueraria Lobata (Willd.) Ohwi (RPL), rhizome of Polygonatum sibiricum Red (RPS), root of Astragalus propinquus Schischkin (RAP), bud of Hemerocallis citrina Baroni (BHC), seed of Nelumbo nucifera Gaertn (SNN) and fruit of Prunus mume (Sieb.) Sieb.etZuce (FPM). The results showed that among all exposures, the treatment with FPE resulted in the significant increase (p < 0.05) of Cd and Pb concentration in shoots and roots of S. nigrum by 32.5% and 65.2% for Cd, and 38.7% and 39.6% for Pb. The biomasses of S. nigrum in all plant extract treatments were not significantly changed (p < 0.05) compared to the control (CK). The Cd and Pb extraction rates of S. nigrum in FPE treatment were increased respectively by 60.5% and 40.5% compared to CK. Though the treatment with EDTA significantly improved (p < 0.05) the concentration of Cd and Pb of S. nigrum, the Cd and Pb masses (ug plant-1) of S. nigrum did not show any significant difference compared to the CK due to the significant decrease in the shoot (20.4%) and root (22.0%) biomasses. The chelative role of FPE might be relation with its higher polyphenolic compounds. However, not sure if the contents of polyphenolic compounds was the only differences between FPE and other additives. Thus, some unknown organic matters might also play active role. This study provided valuable information on improving the phytoremediation potential of hyperaccumulator.

Exogenous jasmonic acid decreased Cu accumulation by alfalfa and improved its photosynthetic pigments and antioxidant system.

Jasmonic acid (JA) is an important phytohormone, which among others may be involved in the regulation of plant accumulating heavy metal. This experiment was designed to explore the effects of exogenous JA on the responses of alfalfa to Cu stress (100 µM) in Hoagland solution. When 1, 5 or 10 mM JA was added to the treatment with Cu addition, Cu concentrations in roots and leaves of alfalfa were significantly decreased (p < 0.05) to some extents compared to the treatment without JA addition. The biomasses of roots and leaves of alfalfa in treatments of JA additions were significantly increased (p < 0.05) compared to the Cu stress treatment. Similarly, the concentrations of Chlorophyll, antioxidant enzyme activities, MDA and H2O2 were improved accordingly. But these factors of JA were not improved further when its concentration added in media was the highest (10 mM), indicating its improvement roles were limited. These results suggested that there were positive roles of exogenous JA on alfalfa decreased its Cu accumulation and toxicities might via reduced oxidative stress.

A repeat region from the Brassica juncea HMA4 gene BjHMA4R is specifically involved in Cd2+ binding in the cytosol under low heavy metal concentrations.

BACKGROUND: HMA4 transporters are involved in the transport and binding of divalent heavy metals (Cd, Zn, Pb [lead] and Co [cobalt]). In general, as efflux pumps, HMA4 transporters can increase the heavy metal tolerance of yeast and Escherichia coli. Additional research has shown that the C-terminus of HMA4 contains a heavy metal-binding domain and that heterologous expression of a portion of peptides from this C-terminal domain in yeast provides a high level of Cd tolerance and Cd hyperaccumulation. RESULTS: We cloned BjHMA4 from Brassica juncea, and quantitative real-time PCR analysis revealed that BjHMA4 was upregulated by Zn and Cd in the roots, stems and leaves. Overexpression of BjHMA4 dramatically affects Zn/Cd distribution in rice and wheat seedlings. Interestingly, BjHMA4 contains a repeat region named BjHMA4R within the C-terminal region; this repeat region is not far from the last transmembrane domain. We further characterized the detailed function of BjHMA4R via yeast and E. coli experiments. Notably, BjHMA4R greatly and specifically improved Cd tolerance, and BjHMA4R transformants both grew on solid media that contained 500 µM CdCl2 and presented improved Cd accumulation (approximately twice that of wild-type [WT] strains). Additionally, visualization via fluorescence microscopy indicated that BjHMA4R clearly localizes in the cytosol of yeast. Overall, these findings suggest that BjHMA4R specifically improves Cd tolerance and Cd accumulation in yeast by specifically binding Cd2+ in the cytosol under low heavy metal concentrations. Moreover, similar results in E. coli experiments corroborate this postulation. CONCLUSION: BjHMA4R can specifically bind Cd2+ in the cytosol, thereby substantially and specifically improving Cd tolerance and accumulation under low heavy metal concentrations.

Strengthening role and the mechanism of optimum nitrogen addition in relation to Solanum nigrum L. Cd hyperaccumulation in soil.

Solanum nigrum L. has a high potential for the remediation of Cd-contaminated soil, and nitrogen fertilizer supply is an effective method to further improve its phytoremediation potential. The soil pot culture experiment was used to explore 4 kinds of nitrogen fertilizers the best fertilizer addition concentrations and their strengthening mechanisms. The results showed that S. nigrum biomass increased with increasing N doses until 800 mg kg-1, where the biomass reached maximum and no longer improved (p < 0.05). However, Cd concentration accumulated by S. nigrum and the extractable Cd concentration in soil did not show a significant decrease (p < 0.05). In this experiment, when N fertilizer was added at 800 mg kg-1 (NH4HCO3, NH4Cl, (NH4)2SO4 and CH4N2O fertilizers), the biomass of the aboveground S. nigrum parts improved to the maximum under (NH4)2SO4 and CH4N2O treatments, i.e. 5.86 g pot-1 and 5.83 g pot-1, increased by 5.92- and 5.89-fold, respectively (p < 0.05), compared to the controls without N fertilizers addition. At the same time, Cd phytoaccumulation in plants was elevated to 128.40 µg pot-1 and 129.14 µg pot-1, increased by 6.20- and 6.24-fold, respectively (p < 0.05), compared to control with no fertilizer added. The results of this experiment demonstrated that Cd phytoextraction capacity (µg pot-1) was the strongest under (NH4)2SO4 and CH4N2O treatments at N content of 800 mg kg-1, when plant nutrient recovery reached the maximum, and these 2 types of nitrogen fertilizers could be utilized to remediate Cd-contaminated soil in field experiments or even in practice.

Selenium spiked in soil promoted zinc accumulation of Chinese cabbage and improved its antioxidant system and lipid peroxidation.

Selenium (Se) and zinc (Zn) are necessary mineral nutrients for human body but millions of people have an inadequate intake of them, and eat food enriched with Se and Zn may minimize these problems. Chinese cabbage is an important food in people's daily life. The aim of this study was to evaluate the effects of single Se, Zn and their combination treatment in soil on their accumulation, antioxidant system and lipid peroxidation in roots and leaves of Chinese cabbage using soil pot culture experiment. When 0.5 mg kg-1 Se +30 mg kg-1 Zn and 1.0 mg kg-1 Se +30 mg kg-1 Zn were spiked in soils, Zn concentrations in roots and leaves of Chinese cabbage were significantly increased (p < 0.05) by 20.2%, 37.8% and 17.9%, 34.1% respectively compared to the treatment of 30 mg kg-1 Zn added, and the latter was significantly higher (p < 0.05) than that of former, indicating Se significantly promoted Zn accumulation. Almost all physiological indexes including POD, SOD, CAT, APX, GR, Chlorophyll a, Chlorophyll b, Carotenoids, MDA and Free proline in the treatments of Se or Zn spiked were significantly improved (p < 0.05) or basically unaffected compared to the control without Se or Zn added. The biomass change trends were similar with these indexes either. These results showed that the addition in soil of Se and Zn significantly increased their accumulation in Chinese cabbage without affected its formal growth. Particularly, the addition of Se promoted Zn accumulation. The conclusions were more important reference for the production practice of cash crop enriched of Se and Zn either.

Enhanced phytoremediation of cadmium and/or benzo(a)pyrene contaminated soil by hyperaccumlator Solanum nigrum L.

The role of same amendment on phytoremediating different level contaminated soils is seldom known. Soil pot culture experiment was used to compare the strengthening roles of cysteine (CY), EDTA, salicylic acid (Sa), and Tween 80 (TW) on hyperaccumulator Solanum nigrum L. phytoremediating higher level of single cadmium (Cd) or Benzo(a)pyrene (BAP) and their co-contaminated soils. Results showed that the Cd capacities (ug pot-1) in shoots of S. nigrum in the combined treatment T0.1EDTA+0.9CY were the highest for the 5 and 15 mg kg-1 Cd contaminated soils. When S. nigrum remediating co-contaminated soils with higher levels of Cd and BAP, that is, 5 mg kg-1 Cd + 1 mg kg-1 BAP and 15 mg kg-1 Cd + 2 mg kg-1 BAP, the treatment T0.9CY+0.9Sa+0.3TW showed the best enhancing remediation role. This results were different with co-contaminated soil with 0.771 mg kg-1 Cd + 0.024 mg kg-1 BAP. These results may tell us that the combine used of CY, SA, and TW were more useful for the contaminated soils with higher level of Cd and/or BAP. In the combined treatments of Sa+TW, CY was better than EDTA.

The difference in antioxidant capacity of four alfalfa cultivars in response to Zn.

The aim of this study was to evaluate antioxidative responses in roots, stem and leaves of four alfalfa cultivars to different concentrations of zinc (Zn) (0, 300, 600 and 900 µM) for 23 days. Among the four cultivars, Aohan displayed the highest Zn concentrations in tissues and the largest Zn amount in aerial parts. Zn stress induced the production of H2O2 and increased the content of free proline and activities of antioxidative enzymes in roots, stem and leaves of Aohan. Based on the above results, we concluded that Aohan is superior to other three cultivars for Zn phyto-remediation, which indicated that Aohan is a novel Zn accumulator and able to tolerate Zn-induced toxicity by activating the antioxidative defense system.

The effect of exogenous plant growth regulators on elevated Cd phytoremediation by Solanum nigrum L. in contaminated soil.

Maximizing amendment potential is an emphasis in the HM-contaminated field of phytoremediation by hyperaccumulators due to the low bioavailability of HMs in soils and small biomass yields of plants. This study investigated the influence of different types and concentrations of plant growth regulators on Cd phytoremediation by Solanum nigrum in contaminated soil. Our conclusions showed that the shoot Cd extractions (µg plant-1) and the root and shoot biomasses at all the treatments remarkedly increased compared with that of the CK (p < 0.05), while the Cd concentrations at root and aboveground parts by S. nigrum, the extractable Cd concentrations, and pH value of soils did not change significantly compared with the CK (p < 0.05). Furthermore, correlation analysis showed that the shoot Cd phytoaccumulation and the root and aboveground biomasses of S. nigrum were particularly dependent upon the application of CTK and GA3 concentration gradient (p < 0.05). Moreover, some related physicochemical indexes were determined for supervising the growth conditions of plants, and these results pointed out that after exogenous PGRs treatments, the chlorophyll content and antioxidative enzymes POD and SOD activities in vivo of plants clearly advanced, while the H2O2 and MDA contents and CAT apparently declined. These consequence demonstrated that the exogenous PGR addition prominently reinforced the Cd phytoextraction capacity of S. nigrum in contaminated soil by stimulating plant growth and increasing shoot yields.

High-efficiency combination washing agents with eco-friendliness simultaneously removing Cd, Cu and Ni from soil of e-waste recycling site: A lab-scale experiment.

Soil washing technology plays an important role in the removal of heavy metals, and the efficacy of this process depends on the washing agent used. Due to the difficulty in treating soils contaminated by multiple heavy metals, there is still a need for further exploration of efficient washing agents with low environmental impact. Although single washing agents, such as chelators, can also effectively remove heavy metals from soil, combining efficient washing agents and determining their optimal washing conditions can effectively improve their removal efficiency for multiple heavy metals in soil simultaneously. Based on the previous research, the present study was carried out to combine different types of washing agents to remediate contaminated soils at a commonly e-waste recycling site. The objectives were to investigate their efficient washing conditions and assess the impact of the washing process on the speciation distribution and pollution level associated with heavy metals in soil. The results showed that the combination of HEDP (1-hydroxyethylidene-1,1-diphosphonic acid) and FeCl3 at a ratio of 6:4 exhibited the most effective removal of Cd, Cu and Ni from the contaminated soil at an e-waste recycling site. Under optimal washing conditions, with a soil-to-liquid ratio of 1:20 and a washing time of 48 h, the removal rates of Cd, Cu and Ni were 96.72%, 69.91% and 76.08%, respectively. It needed to be emphasized that the combination washing agents were able to remove most of the acid-soluble, reducible and oxidizable fractions of heavy metals, and even the removal rates of the stable residual fraction (e.g., of Cd) was at a relatively high level. In addition, the washing process significantly reduced the pollution level associated with heavy metals in soil. This study aid in the development of combined efficient washing agents and explores optimal washing strategies for the remediation of Cd, Cu, and Ni-contaminated soil at e-waste recycling sites. The findings may play a role in enhancing the remediation capabilities for soils contaminated with multiple heavy metals, due to its characteristics of and high-efficiency and environmental friendliness.

Effect of ammonium sulfate combined with aqueous bio-chelator on Cd uptake by Cd-hyperaccumulator Solanum nigrum L.

The efficacy of using plants to phytoremediate heavy metal (HM) contaminated soils can be improved using soil amendments. These amendments may both increase plant biomasses and HMs uptake. We aimed to determine the composite effect of ammonium sulfate ((NH4)2SO4) combined with the application of an aqueous stem-extracted bio-chelator (Bidens tripartita L) on the plant biomasses and cadmium (Cd) phytoextraction by Solanum nigrum L. The constant (NH4)2SO4 application mode plus bio-chelator additives collectively enhanced the shoot Cd extraction ability owing to the increased plant biomass and shoot Cd concentration by S. nigrum. The shoot Cd extraction and the soil Cd decreased concentration confirmed the optimal Cd phytoextraction pattern in K8 and K9 treatments (co-application of (NH4)2SO4 and twofold/threefold bio-chelators). Accordingly, Cd contamination risk in the soil (2 mg kg-1) could be completely eradicated (<0.2 mg kg-1) after three rounds of phytoremediation by S.nigrum based on K8 and K9 treatments through calculating soil Cd depletion. The microorganism counts and enzyme activities in rhizosphere soils at treatments with the combined soil additives apparently advanced. In general, co-application mode of (NH4)2SO4 and aqueous bio-chelator was likely to be a perfect substitute for conventional scavenger agents on account of its environmental friendliness and cost saving for field Cd contamination phytoremediation by S. nigrum.

Effects of combined microplastics and heavy metals pollution on terrestrial plants and rhizosphere environment: A review.

Microplastics (MPs) can enter the soil environment through industry, agricultural production and daily life sources. Their interaction with heavy metals (HMs) poses a significant threat to a variety of terrestrial ecosystems, including agricultural ones, thereby affecting crop quality and threatening human health. This review initially addresses the impact of single and combined contamination with MPs and HMs on soil environment, including changes in soil physicochemical properties, microbial community structure and diversity, fertility, enzyme activity and resistance genes, as well as alterations in heavy metal speciation. The article further explores the effects of this pollution on the growth characteristics of terrestrial plants, such as plant biomass, antioxidant systems, metabolites and photosynthesis. In general, the combined contaminants tend to significantly affect soil environment and terrestrial plant growth, i.e., the impact of combined contaminants on plants weight ranged from -87.5% to 4.55%. Similarities and differences in contamination impact levels stem from the variations in contaminant types, sizes and doses of contaminants and the specific plant growth environments. In addition, MPs can not only infiltrate plants directly, but also significantly affect the accumulation of HMs in terrestrial plants. The heavy metals concentration in plants under the treatment of MPs were 70.26%-36.80%. The co-occurrence of these two pollution types can pose a serious threat to crop productivity and safety. Finally, this study proposes suggestions for future research aiming to address current gaps in knowledge, raises awareness about the impact of combined MPs + HMs pollution on plant growth and eco-environmental security.

A comparative study on cadmium tolerance and applicability of two Solanum lycopersicum L. cultivars.

Solanum lycopersicum L. can be classified into low Cd-accumulating and high Cd-accumulating types based on their accumulation characteristics of cadmium (Cd). There are many common S. lycopersicum varieties available in the market, but their specific Cd tolerance and enrichment abilities are not well understood. This article uses two S. lycopersicum cultivars, Yellow Cherry and Yellow Pearl, as experimental materials. The experimental method of soil pot planting was adopted, and Cd concentrations in the soil were added at 0, 0.6, 1.5, 2.5, 5, and 10 mg/kg. The changes in Cd content, biomass, photosynthetic pigment content, and photosynthetic parameters of the two S. lycopersicum cultivars were analyzed to screen for low-accumulation S. lycopersicum cultivars. The results showed that S. lycopersicum are Cd-sensitive plants. The Cd accumulation, photosynthetic parameters, and other basic indicators of Yellow Cherry basically showed significant differences when the soil Cd concentration was 0.6 mg/kg, and the biomass showed significant differences when the soil Cd concentration was 1.5 mg/kg. Except for the Cd accumulation in the roots and leaves of Yellow Pearl, which showed significant differences at a soil Cd concentration of 0.6 mg/kg, the other indicators basically showed significant differences when the soil Cd concentration was 1.5 mg/kg. When the soil Cd concentration was 0.6 mg/kg, the Cd accumulation in the fruit of Yellow Pearl was 0.04 mg/kg, making it a low-accumulation S. lycopersicum variety suitable for promoting cultivation in Cd-contaminated soil at 0.6 mg/kg. In conclusion, the Cd accumulation in the fruit of Yellow Pearl is significantly lower than that of Yellow Cherry and even below the Cd limit value for fresh vegetables specified in GB2762-2017. Therefore, Yellow Pearl can be grown as edible crops in soils with Cd concentrations ≤0.6 mg/kg. Furthermore, Yellow Cherry demonstrate strong Cd tolerance and can be used for the remediation of Cd-contaminated soils.

Cadmium phytoextraction efficiency of hyperaccumulator as affected by harvest stage in three continuous years.

Phytoremediation which mainly using hyperaccumulator is a very popular and environmental-friendly clean method. Long term continuous test is very important due to its low remediation efficiency in a growth period. Cd hyperaccumulator Rorippa globosa (Turcz.) Thell. Was used to explore the effect of two remediation modes (harvests at flowering and maturity stages) on the continuous remediation efficiency in a 3-year experiment using pot experiment with real Cd contaminated soil. The results showed that the biomass in maturity-harvest treatments was 1.12 times of that in flowering-harvest treatments due to the short vegetation time. Shoot Cd concentrations in the flowering-harvest treatments were on average 15.4% lower compared to the maturity-harvest treatments either. However, the Cd phytoextraction efficiency (PE) in the flowering-harvest treatments was 13.8% higher compared to the harvests at the maturity stage due to the growth cycle of R. globosa harvested at the flowering was 34.5% of shorter compared to those in the maturity harvest treatments. After three consecutive years of R. globosa phytoextraction, the concentration of extractable Cd decreased on average by 28.7% and corresponding PEs lower either. It was suggested that cultivation modes of R. globosa and low-accumulation crop rotation, or three times flowering harvests of R. globosa per year seemed to be a good choice in practical solution.

Investigating subtypes of lung adenocarcinoma by oxidative stress and immunotherapy related genes.

Lung adenocarcinoma (LUAD) is one of the most widespread and fatal types of lung cancer. Oxidative stress, resulting from an imbalance in the production and accumulation of reactive oxygen species (ROS), is considered a promising therapeutic target for cancer treatment. Currently, immune checkpoint blockade (ICB) therapy is being explored as a potentially effective treatment for early-stage LUAD. In this research, we aim to identify distinct subtypes of LUAD patients by investigating genes associated with oxidative stress and immunotherapy. Additionally, we aim to propose subtype-specific therapeutic strategies. We conducted a thorough search of the Gene Expression Omnibus (GEO) datasets. From this search, we pinpointed datasets that contained both expression data and survival information. We selected genes associated with oxidative stress and immunotherapy using keyword searches on GeneCards. We then combined expression data of LUAD samples from both The Cancer Genome Atlas (TCGA) and 11 GEO datasets, forming a unified dataset. This dataset was subsequently divided into two subsets, Dataset_Training and Dataset_Testing, using a random bifurcation method, with each subset containing 50% of the data. We applied consensus clustering (CC) analysis to identify distinct LUAD subtypes within the Dataset_Training. Molecular variances associated with oxidative stress levels, the tumor microenvironment (TME), and immune checkpoint genes (ICGs) were then investigated among these subtypes. Employing feature selection combined with machine learning techniques, we constructed models that achieved the highest accuracy levels. We validated the identified subtypes and models from Dataset_Training using Dataset_Testing. A hub gene with the highest importance values in the machine learning model was identified. We then utilized virtual screening to discover potential compounds targeting this hub gene. In the unified dataset, we integrated 2,154 LUAD samples from TCGA-LUAD and 11 GEO datasets. We specifically selected 1,311 genes associated with immune and oxidative stress processes. The expression data of these genes were then employed for subtype identification through CC analysis. Within Dataset_Training, two distinct subtypes emerged, each marked by different levels of immune and oxidative stress pathway values. Consequently, we named these as the OX+ and IM+ subtypes. Notably, the OX+ subtype showed increased oxidative stress levels, correlating with a worse prognosis than the IM+ subtype. Conversely, the IM+ subtype demonstrated enhanced levels of immune pathways, immune cells, and ICGs compared to the OX+ subtype. We reconfirmed these findings in Dataset_Testing. Through gene selection, we identified an optimal combination of 12 genes for predicting LUAD subtypes: ACP1, AURKA, BIRC5, CYC1, GSTP1, HSPD1, HSPE1, MDH2, MRPL13, NDUFS1, SNRPD1, and SORD. Out of the four machine learning models we tested, the support vector machine (SVM) stood out, achieving the highest area under the curve (AUC) of 0.86 and an accuracy of 0.78 on Dataset_Testing. We focused on HSPE1, which was designated as the hub gene due to its paramount importance in the SVM model, and computed the docking structures for four compounds: ZINC3978005 (Dihydroergotamine), ZINC52955754 (Ergotamine), ZINC150588351 (Elbasvir), and ZINC242548690 (Digoxin). Our study identified two subtypes of LUAD patients based on oxidative stress and immunotherapy-related genes. Our findings provided subtype-specific therapeutic strategies.

Toxicity of emerging contaminant antibiotics in soil to Capsicum annuum L. growth and their effects on it accumulating copper.

Antibiotics are a kind of emerging contaminant in soil. Tetracycline (TC) and oxytetracycline (OTC) in soil are often detected, even with very high concentration in the soils of facility agriculture due to their good effect, low price and large usage. Copper (Cu) is common heavy metal pollutant in soil. The toxicity roles of TC, OTC and/or Cu in soil on a commonly consumed vegetable Capsicum annuum L. and its Cu accumulation were not clear till now. The results of pot experiment showed that the TC or OTC added in soil alone didn't produce poison effects for C. annuum after 6 weeks and 12 weeks growth reflected by some physiological index like SOD, CAT and APX activities changes, while the biomass changes affirmed them either. Cu contaminated soil significantly inhibited the growth of C. annuum. Furthermore, combined pollution of Cu with TC or OTC was with more serious suppression of C. annuum growth. The suppression role of OTC was heavier than TC in Cu and TC or OTC contaminated soil. Such phenomenon was relevant with the role of TC or OTC increased Cu concentration in C. annuum. The improvement role of TC or OTC on Cu accumulation in C. annuum caused by the increased extractable Cu concentration in soil. The study demonstrated that TC or OTC added in soil alone was without any toxicity to C. annuum. But they may aggravate the hurt of C. annuum caused by Cu through increased its accumulation from soil. Thus, such combine pollution should be avoided in safe agricultural product.

The effects of salinity and pH variation on hyperaccumulator Bidens pilosa L. accumulating cadmium with dynamic and real-time uptake of Cd2+ influx around its root apexes.

Bidens pilosa L. has been confirmed to be a potential Cd hyperaccumulator by some researchers, but the dynamic and real-time uptake of Cd2+ influx by B. pilosa root apexes was a conundrum up to now. The aim of our study was to investigate the effects of salinity and pH variations on the characteristics of Cd2+ influx around the root apexes of B. pilosa. The tested seedlings of B. pilosa were obtained by sand culture experiments in a greenhouse after 1 month from germination, and the Cd2+ influxes from the root apex of B. pilosa under Cd treatments with different salinity and pH levels were determined with application of non-invasive micro-test technology (NMT). The results showed that Cd2+ influxes at 300 µm from the root tips decreased under Cd treatments with 5 mM and 10 mM NaCl, as compared to Cd stress alone. However, Cd treatments with 2.5 mM NaCl had little effect on the net Cd2+ influxes, as compared to Cd treatments alone. Importantly, Cd treatments at pH = 4.0 markedly increased Cd2+ influxes in roots, and Cd treatment at pH = 7.0 had no significant effect on the net Cd2+ influxes compared to Cd treatments at pH = 5.5. Results also showed that Cd treatments with 10 mM NaCl significantly decreased concentrations of chlorophyll (Chl) a and b in leaves and root vigor of B. pilosa relative to Cd treatments alone, while there were no significant differences between Cd treatments with 2.5 mM NaCl and Cd treatments alone. But root vigor was inhibited significantly under Cd treatments with 5 mM and 10 mM NaCl. A significant increase of root vigor was observed in Cd treatments at pH = 4.0, as compared to pH = 5.5. The Cd treatments with high and medium concentrations of NaCl inhibited the uptake of Cd by B. pilosa roots and affected the Chl and root vigor further. But the Cd treatments at pH = 4.0 could promote the Cd uptake and root vigor. Our results revealed the uptake mechanisms of B. pilosa as a potential phytoremediator under different salinity and pH levels combined with Cd contamination and provided a new idea for screening ideal hyperaccumulator and constructing evaluation system.