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At least 19 recordsLinked to original sources
PubMed1978

Soil and plant factors influencing the accumulation of heavy metals by plants.

The use of plants to monitor heavy metal pollution in the terrestrial environment must be based on a cognizance of the complicated, integrated effects of pollutant source and soil-plant variables. To be detectable in plants, pollutant sources must significantly increase the plant available metal concentration in soil. The major factor governing metal availability to plants in soils is the solubility of the metal associated with the solid phase, since in order for root uptake to occur, a soluble species must exist adjacent to the root membrane for some finite period. The rate of release and form of this soluble species will have a strong influence on the rate and extent of uptake and, perhaps, mobility and toxicity in the plant and consuming animals. The factors influencing solubility and form of available metal species in soil vary widely geographically and include the concentration and chemical form of the element entering soil, soil properties (endogenous metal concentration, mineralogy, particle size distribution), and soil processes (e.g., mineral weathering, microbial activity), as these influence the kinetics of sorption reactions, metal concentration in solution and the form of soluble and insoluble chemical species. The plant root represents the first barrier to the selective accumulation of ions present in soil solution. Uptake and kinetic data for nutrient ions and chemically related nonnutrient analogs suggest that metabolic processes associated with root absorption of nutrients regulate both the affinity and rate of absorption of specific nonnutrient ions. Detailed kinetic studies of Ni, Cd, and Tl uptake by intact plants demonstrate multiphasic root absorption processes over a broad concentration range, and the use of transport mechanisms in place for the nutrient ions Cu, Zn, and K. Advantages and limitations of higher plants as indicators of increased levels of metal pollution are discussed in terms of these soil and plant phenomena.

Absorption↗
PubMed2026

Biomonitoring of industrial heavy metal pollution via enzymatic and metabolic responses in desert ants (Cataglyphis savignyi) and beetles (Tentyrum sp) as bioindicators.

The current work seeks to evaluate the effectiveness of Cataglyphis saviginyi and Tentyrum sp as indicators of pollution in the city's main industrial regions by analyzing their enzymatic activity and primary metabolites. Soil samples were collected at each site under investigation to analyze soil characteristics and heavy metal content. C. saviginyi and Tentyrum sp were collected across four consecutive seasons (2023-2024) to investigate enzymatic (GPT, GOT, ALP, ACP, LDH) and metabolic (lipid, protein, carbohydrate) biomarkers. The physicochemical properties of the soil differed substantially between the industrial areas and the control site. Soil heavy metal buildup was highest at industrial sites (1 and 4) compared to the control site, with the order being Zn > Cr > Cd > Cu. Heavy metal pollution indices were determined. Increased industrial activity from metal industries, ceramics, and chemical painting companies defines this area, as seen by the high Cdeg, mCd, PI, and PLI values derived for industrial sites 1 and 4. While C. saviginyi and Tentyrum sp deconcentrated and released Cr, Cd, and Zn into the soil via the biological accumulation factor (BAF), Cu acted as a macro-concentrator. Compared with the control site, industrial environments were shown to increase levels of GPT, GOT, LDH, ACP, protein, and carbohydrates in C. saviginyi. However, lipid and ALP activity was suppressed. at industrial sites, Tentyrum sp carbohydrate content was higher than at control sites, but GPT, GOT, ALP, ACP, LDH, protein, and lipid activities were all suppressed. Consequently, enzymatic and metabolic biomarkers proved to be sensitive indicators for assessing industrial heavy metal pollution in desert ecosystems.

Animals↗
PubMed2026

The removal of iron and phosphate from culture medium by Rhodococcus ruber SiAl.

The microbial accumulation of heavy metals and phosphate is of interest for the bioremediation of polluted waters. In this work, we showed that at cultivation of the bacterium Rhodococcus ruber SiAl in the medium with 2.0 mM Fe³⁺ for stationary growth stage, up to 99% of the iron was associated with the biomass. Magnesium ion accumulation from the medium with 2 mM Mg²⁺ did not exceed 5% of the initial content. The cells did not remove manganese ions from the medium; moreover, the presence of MnSO4 inhibited growth. The cells of Rhodococcus ruber SiAl removed phosphate from the medium: 75, 20, and 10% of the initial phosphate content was removed during cultivation in the presence of 6 mM phosphate and 2 mM Fe³⁺, 2 mM Mg²⁺, or 2 mM Mn²⁺, respectively. In the genome of R. ruber SiAl, genes encoding proteins of the siderophore synthesis systems and phosphate transport systems were identified. The strain was the most efficient for iron accumulation, which suggests a promising application for the removal of phosphate and iron from polluted waters.

Rhodococcus ruber↗
PubMed1977

Microorganisms as indices of environmental pollution by smelting industry.

The aim of the study was to prove suitability of some microbiological tests for determination of the degree of soil pollution by copper industry. The microbiological tests reveal sensitivity to metal compounds present in dusts emitted by smelters. The sensitivity of the selected strains to the dust present in the agar medium and soil has been determined and 30 strains, of which 50% reacted to the presence of 1--2 g of the dust in medium, were recommended for the tests. The tests showed accumulation of heavy metals contained in the dust mainly in the upper soil horizons and the highest pollution with the dust approximately 800 m away from the emitor in northeastern direction, which is the direction of prevailing winds of that area. The results obtained are in accordance with theoretical assumption as well as with the literature based on chemical analyses of polluted soil.

Bacteria↗
PubMed1979

Cadmium in forest ecosystems around lead smelters in Missouri.

The development of Missouri's new lead belt within the past decase has provided an excellent opportunity to study the dissemination and effects of heavy metals in a deciduous forest ecosystem. Primary lead smelters within the new lead belt have been identified as potential sources of cadmium as well as lead, zinc, and copper. Sintering and blast furnace operations tend to produce significant quantities of small particulates highly enriched in cadmium and other heavy metals. At one smelter, samples of stack particulate emissions indicate that as ms accompanied by 0.44 lb zinc, 4.66 lb lead, and 0.01 lb copper/hr. These point-source emissions, as well as a number of other sources of fugitive (wind blown) and waterborne emissions contribute to a significant deposition of cadmium in the surrounding forest and stream beds. Mobilization of vagrant heavy metals may be significantly increased by contact of baghouse dusts or scrubber slurries with acidic effluents emanating from acid plants designed to produce H2SO4 as a smelter by-product. Two separate drainage forks within the Crooked Creek watershed permit some comparisons of the relative contributions of cadmium by air-borne versus water-borne contaminants. Cadmium and other heavy metals have been found to accumulate in the forest litter and partially decomposed litter along stream beds. Greater solubility, lower levels of complexation with organic ligands in the litter, and greater overall mobility of cadmium compared with lead, zinc, and copper result in appreciable contributions of dissolved cadmium to the watershed runoff. The present paper attempts to define the principle sources and current levels of heavy metal contamination and summarizes the efforts undertaken by the industry to curtail the problem.

Air Pollutants↗
PubMed2026

From ecological threats to environmental solutions: a critical review of invasive plant species for heavy metal phytoremediation.

Heavy metal contamination represents a persistent environmental challenge threatening ecosystem stability, agricultural productivity, and human health. Therefore, the development of sustainable and cost-effective remediation strategies is essential. Phytoremediation, an environmentally compatible approach that utilizes plants and their associated biological processes to reduce contaminant mobility, bioavailability, and toxicity, has gained increasing attention as an alternative to conventional remediation techniques. Among potential phytoremediation candidates, invasive plant species (IPS) have attracted interest due to their rapid growth, high biomass production, extensive root systems, physiological plasticity, and tolerance to stressful environments, including heavy metal contamination. Species such as Alternanthera philoxeroides, Arundo donax, Eichhornia crassipes, and Pistia stratiotes have demonstrated potential for metal uptake, accumulation, immobilization, or tolerance in contaminated ecosystems. This review critically examines the role of invasive plants in heavy metal phytoremediation by evaluating the physiological, biochemical, and ecological traits that influence remediation outcomes. Key mechanisms, including phytoextraction, phytostabilization, rhizosphere-mediated processes, and plant-microbe interactions, are discussed using evidence from contaminated soil and aquatic environments. The potential advantages of invasive plants, particularly their high biomass production and environmental adaptability, are evaluated alongside ecological concerns associated with their utilization. Importantly, invasion success does not necessarily translate into remediation success, and the effectiveness of invasive plants depends on contaminant characteristics, ecosystem conditions, and management practices. Major challenges, including uncontrolled spread, ecosystem disruption, contaminated biomass management, and limited field-scale validation, are critically assessed. Overall, invasive plants represent context-dependent remediation resources rather than universal solutions. Their application requires integrated risk assessment, containment strategies, long-term monitoring, and evidence-based management frameworks to maximize remediation benefits while minimizing ecological risks.

Contamination↗
PubMed1979

Bioavailability of Cd to Food crops in relation to heavy metal content of sludge-amended soil.

Results of greenhouse and laboratory experiments on factors influencing uptake and accumulation of Cd by economic crops are summarized.Tolerance to Cd is highly crop-specific. For example, 21 different economic crops were grown in pots filled with a calcareous soil treated with increasing amounts of Cd. Yields versus Cd addition rate relations showed yield reductions to occur with Cd sensitive plants (spinach, soybean, curlycress, and lettuce) at addition rates varying from 5 to 15 mug Cd/g soil, whereas tolerant crops (tomato, squash, cabbage, and rice) did not suffer a yield reduction when treated at rates less than 150 mug Cd/g soil. Nutrient solution experiments likewise revealed marked differences in growth of crops. Corn, turnip, beets, bean, and tomato plants grown in solution cultures containing 0.1 mug Cd/ml accumulated different amounts of Cd in leaf tissue depending upon crop species; leaf Cd concentrations ranged from a low of 9 mug Cd/g leaf for beans to 200 mug Cd/g leaf for beets. Large differences also occur with regard to distribution of Cd within the plant. Fruit and seed tissue contain less Cd than leaves. Experiments comparing the toxicity of Cd to Cu, Ni, and Zn in an acid soil +/- lime showed Cd to be the most phytotoxic. While interactive effects occur with regard to metal uptake and accumulation by plants, Cd uptake is essentially dependent upon the Cd concentration of the soil. Studies of chemical speciation of Cd in relation to Cd availability indicate that the free Cd(2+) concentration correlates better with Cd uptake than Cd total of the soil solution.

Agriculture↗
PubMed2026

Silicon-mediated alleviation of mercury toxicity requires coordinated regulation of antioxidant defense, metal homeostasis, and nodule function in mung bean.

Mercury (Hg) contamination and accumulation in agricultural soil represent a major hazardous environmental concern, posing serious threats to living organisms, including plants. Silicon (Si) has been widely recognized to mitigate heavy metal (loid) toxicity; however, the underlying mechanism of Si-mediated mitigation of Hg-stress in mung bean remains unclear. In this study, we addressed this research gap by thoroughly examining the potential effects of Si supplementation on Hg-stressed mung bean plants, with particular emphasis on investigating the possible effects of Si on plant biomass, nodulation traits, antioxidant defense, and expression of metal-transporter and detoxification genes. Our findings demonstrated that Hg stress significantly impaired plant growth by inducing oxidative stress and reducing biological nitrogen fixation efficiency whereas Si application significantly alleviated the Hg-induced toxicity. Specifically, Si increased shoot dry biomass by +113% (2.13-fold), root dry biomass by +60% (1.60-fold), nodule number by +152% (2.52-fold), and nodule dry weight by +273% (3.73-fold) under Hg stress compared to Hg treated plants only. Furthermore, Si enhanced antioxidant defense system, restricted the uptake and accumulation of Hg in different plant tissues, and regulated the expression of genes related to metal transport and detoxification, contributing to improved nodulation and nitrogen fixation under Hg stress. Overall, our findings demonstrate that Si application mitigates the Hg-induced toxicity in mung bean plants by enhancing antioxidant defense, improving nitrogen fixation, regulation of genes involved in metal transport and detoxification, and limiting Hg accumulation.

Vigna radiata↗
PubMed2026

ARR1 and ARR12 negatively regulate arsenic stress tolerance by controlling flavonoid metabolism in Arabidopsis.

ARR1/12-mediated cytokinin signaling negatively regulates the accumulation of glycosylated flavonoids, thereby increasing plant susceptibility to As(III) stress. Cytokinins negatively regulate arsenic stress tolerance in plants through cytokinin-signaling type-B Arabidopsis response regulators (B-ARRs), specifically ARR1 and ARR12. However, the mechanism by which cytokinin signaling regulates plant metabolite dynamics, particularly antioxidant flavonoids, in response to arsenic toxicity remains largely unknown. Here, we hypothesized that ARR1/12-mediated cytokinin signaling modulates flavonoid metabolism to regulate arsenite [As(III)] tolerance. By comparing the global metabolic changes in roots of the arr1 12 double mutant (rD) and wild-type (WT) plants, we found that As(III) stress globally reduced metabolite abundance in WT roots. Importantly, the rD mutant accumulated significantly more flavonoids, most in glycosylated forms, than WT under As(III) exposure, which was supported by the specific upregulation of UDP-glycosyltransferase genes involved in flavonoid glycosylation. Accordingly, exogenous application of the glycosylated quercitrin-enhanced As(III) tolerance in WT roots, strengthening that the increase of glycosylated flavonoids in rD roots was beneficial for plant survival under As(III) exposure. Our data collectively strongly support that the increased glycosylation of flavonoids in the rD mutant improves their antioxidant functionality, thereby enhancing the As(III) stress tolerance. This study provides a new insight into the negative role of cytokinin signaling in repressing glycosylated flavonoid accumulation, causing increased susceptibility of plants to As(III) stress. Manipulation of cytokinin signaling or flavonoid glycosylation is, therefore, a promising approach for heavy metal stress mitigation in crops.

Arabidopsis↗
PubMed1979

[Behaviour of the hepatic glutathione (GSH) in the rat in continuous administration of hexachlorobenzene (HCB) (author's transl)].

Adult male Wistar rats were fed with a diet containing 0.05% hexachlorobenzene (HCB) over a period of at least 90 days. At intervals group of 4 animals each were killed and the GSH- and cytochrom P-450-content, the 7-ethoxycoumarin-deethylation activity were measured in the liver. At the same time the urinary porphyrin excretion was determined. After ten days a massive induction of the microsomal mixed function monooxygenase system could be demonstrated, whereas the porphyria (e.g. an increased excretion of urinary porphyrins) became manifest after 56 days HCB-exposure. At the same time (56th day of experiment) the GSH content in the liver rapidly decreased. It is assumed that at the beginning of th HCB-feeding the microsomal mixed function monooxygenase are induced and the uroporphyrinogen decarboxylase is inhibited. This inhibition causes an accumulation of highly carboxylated porphyrins in the liver. Later on (around the 56th day of HCB exposure) a hepatic GSH decrease leads to an increase of heavy metal ions and to a disturbance of the heme biosynthesis that means the manifestation of the HCB-porphyria.

Animals↗
PubMed2026

Plant-derived and microbial biostimulants in sustainable agriculture: mechanisms, applications, and challenges.

Plant biostimulants have emerged as transformative and sustainable tools for improving crop productivity, resource-use efficiency, and resilience under rapidly intensifying environmental stresses. Unlike conventional agrochemicals, biostimulants function by activating physiological, biochemical, and molecular processes that optimize plant performance without directly supplying nutrients or exerting pesticidal effects. This review comprehensively examines the integrated roles of plant-derived and microbial biostimulants in sustainable agriculture, with particular emphasis on microbial-mediated mechanisms underlying plant stress adaptation and rhizosphere functioning. Plant-derived biostimulants, including seaweed extracts, humic substances, protein hydrolysates, amino acids, and chitosan, enhance nutrient acquisition, root architecture, hormonal regulation, and antioxidant defense systems. More importantly, microbial biostimulants, such as plant growth-promoting rhizobacteria (PGPR), endophytic microorganisms, mycorrhizal fungi, actinomycetes, yeasts, and cyanobacteria, exert multifunctional effects through biological nitrogen fixation, mineral solubilization, phytohormone biosynthesis, volatile signaling, osmolyte accumulation, pathogen suppression, and modulation of stress-responsive genes. These beneficial microorganisms reshape rhizosphere microbial communities, improve nutrient cycling, and enhance plant tolerance to drought, salinity, heat, and heavy metal toxicity. Emerging evidence from genomics, transcriptomics, metabolomics, and microbiome-based investigations has further revealed the molecular networks and signaling pathways governing biostimulant-induced resilience and plant-microbe interactions. Despite their substantial promise, inconsistent field performance, formulation instability, regulatory limitations, and inadequate mechanistic understanding continue to restrict their large-scale adoption. This review highlights recent advances in microbial and plant-derived biostimulants while identifying critical knowledge gaps and future opportunities for precision biostimulant engineering, microbiome manipulation, and climate-resilient crop management. The integration of next generation biostimulant technologies into sustainable agricultural systems may significantly reduce dependence on agrochemicals while improving crop productivity, environmental sustainability, and global food security.

Agriculture↗
PubMed1978

Occurrence and fate of organic and inorganic contaminants in marine animals.

Most chemical contaminants occur in highest concentrations in coastal waters, often maximized in very localized areas. In general, this situation represents the exposure pattern for marine animals. However, the availability of contaminant to an organism depends not only on its concentration but also on its chemical nature, its physical state, and whether the source of exposure is the surrounding seawater or the diet. Depending on the type of exposure, uptake occurs across absorptive surfaces, such as those of the respiratory apparatus or gastrointestinal tract, where selectivity may occur, even among neighboring homologs. Deposition in tissues, accumulation, degradation, or depuration depends on tissue type, metabolic processes, detoxification mechanisms, and the adaptive status of a particular animal. This hypothesis is examined briefly for hydrocarbons, pesticides, other miscellaneous organic contaminants, heavy metals, and radionuclides. It is concluded that most data relate to occurrence and distribution. Considerably less information is available on the underlying biochemical processes.

Animals↗
PubMed2026

Heavy metal stress in native plant species: investigating phytoremediation potential through physiological and ISSR/SCoT molecular assessments.

In emerging countries, increased industrial activity has a significant impact on economic growth and urban development. However, the acceleration of industrial processes is accompanied by the release of contaminants such as heavy metals. According to the World Health Organization, one-fourth of all human diseases are caused by environmental contaminants, including heavy metals, which can impair numerous organs such as the neurological system, liver, and reproductive systems. This increased efforts to find effective and sustainable methods to remove heavy metals. Phytoremediation is an environmentally benign method of removing heavy metals using specific plants. Thus, from industrially contaminated locations, common native plant species of Lactuca serriola, Sisymbrium irio, Chenopodium murale, and Cynanchum acutum were selected for this study to assess the mechanisms of their molecular and physiological tolerance. Soil and plants were tested for heavy metals (Cd, Pb, and Cu), and contaminated locations were classified as low and highly polluted. Measurements were made of soluble sugar, protein, secondary metabolites, malondialdehyde, and H2O2. Additionally, inter simple sequence repeat (ISSR), start codon targeted (SCoT), and genomic template stability GTS were used. In heavily polluted areas, all plant species exhibit elevated amounts of sugar, proteins, H2O2, MDA, and secondary metabolites, while total phenolics showed a unique significant interaction (plant-location), where Cynanchum exhibited a hyper-stress phenolic accumulation to cope with toxicity, whereas Chenopodium maintained genomic stability with balanced phenolic level. Based on these findings, both Cynanchum acutum and Chenopodium murale demonstrate superior potential for phytoremediation and warrant further investigation for ecological restoration.

Heavy metal↗
PubMed2026

Chemometric insights into Lactiplantibacillus plantarum effects on onion (Allium cepa L.) metabolism and antidiabetic activity under cadmium stress.

Cadmium (Cd) is a toxic heavy metal that causes severe physiological damage in plants, inhibiting growth and ultimately reducing crop yield. Lactic acid bacteria regulate Cd availability through bioaccumulation and biosorption. This study evaluated the Cd tolerance of Lactiplantibacillus plantarum 10CH by determining its survival capacity under Cd stress and its potential to mitigate Cd-induced stress in onion (Allium cepa L.). The bacterial strain tolerated Cd concentrations up to 100 µM, and whole-genome sequencing identified genes involved in Cd biosorption, accumulation, and efflux. Exposure of onion to increasing CdCl2 concentrations significantly reduced root and shoot biomass. Inoculation with Lb. plantarum 10CH alleviated Cd stress at 100 µM, enhancing root and shoot biomass, reducing Cd accumulation, lowering oxidative damage markers, and stimulating antioxidant enzyme activities. Metabolic profiling revealed that Cd stress significantly reduced primary metabolites and amino acids, particularly at 100 µM, while bacterial inoculation restored key amino acids and peptides, including arginine, tyrosine, and glutamic acid. Chemometric analysis using unsupervised (PCA) and supervised (OPLS-DA) models revealed clear metabolite variation among untreated, Cd-stressed, and bacterial inoculated Cd-stressed onion leaves. Furthermore, leaf extracts exhibited α-glucosidase inhibitory activity, with the highest activity in control plants (IC50 = 425.2 ± 0.5 µg/mL). Cd-stressed plants showed moderate antidiabetic activity, which was significantly reduced by bacterial inoculation. Overall, these findings demonstrate that Lb. plantarum 10CH can survive under Cd stress and alleviates Cd-induced stress in onion, highlighting its potential as a bioinoculant to mitigate heavy metal stress.

Onions↗