Search Results (224)

Wild edible mushrooms are increasingly recognised for their nutritional and therapeutic potential, owing to their richness in bioactive compounds and antioxidant properties. This study assessed the chemical composition, antioxidant capacity, and bioaccumulation of heavy metals (Cd, Pb, Ni) in Boletus edulis, Imleria badia, and Leccinum scabrum collected from two forested regions of north-western Poland differing in anthropogenic influence and soil characteristics. The analysis encompassed structural polysaccharides (β- and α-glucans, chitin), carotenoids, L-ascorbic acid, phenolic and organic acids. B. edulis exhibited the highest β-glucan and lycopene contents, but also the greatest cadmium accumulation. I. badia was distinguished by elevated ascorbic and citric acid levels and the strongest DPPH radical scavenging activity, while L. scabrum showed the highest ABTS and FRAP antioxidant capacities and accumulated quinic acid and catechin. Principal component analysis indicated strong correlations between antioxidant activity and phenolic acids, while cadmium levels were inversely associated with antioxidant potential and positively correlated with chitin. Although all metal concentrations remained within EU food safety limits, B. edulis showed consistent cadmium bioaccumulation. From a practical perspective, the results highlight the importance of species selection and sourcing location when considering wild mushrooms for consumption or processing, particularly in the context of nutritional value and contaminant load. Importantly, regular or excessive consumption of B. edulis may result in exceeding the tolerable weekly intake (TWI) levels for cadmium and nickel, which warrants particular attention from a food safety perspective. These findings underscore the influence of species-specific traits and environmental conditions on mushroom biochemical profiles and support their potential as functional foods, provided that metal contents are adequately monitored. Full article

Suaeda salsa is relatively tolerant to cadmium (Cd) contamination. In order to investigate the bioaccumulation and stress responses of S. salsa under chronic exposure, we explored the growth, accumulation, and changes in antioxidant enzymes and glutathione (GSH) under different Cd concentrations over a 30-day soil culture experiment. Seedling height and weight in the 13.16 mg/kg Cd group were 13.26 cm and 0.21 g, significantly higher than the control group. Growth was significantly inhibited under high Cd concentration exposure, with a seedling and root length of 9.65 cm and 3.77 cm. The Cd concentration in all tissues was positively related to Cd treatment concentration, with the Cd contents in the roots being higher than in the other tissues. At a subcellular level, Cd was mainly concentrated in the cell walls, organelles, and soluble components within the range of 0.05–8.29, 0.02–2.40 and 0.08–1.35 μg/g, respectively. The accumulation of Cd in the roots tracked its proportion in the cell walls. The malondialdehyde (MDA) content of the plant tissues increased with increasing Cd concentration, indicating that Cd stress caused oxidative damage. The GSH content increased with increasing Cd concentration, with maximum values of 0.515 μmol/g in the stem in the 66.07 mg/kg Cd group. The catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) activity showed different change trends under Cd exposure. The results in this study could provide useful information on the tolerance mechanism of Cd in S. salsa, which provides information for exploiting S. salsa as a candidate for phytoremediation of Cd contamination. Full article

Phytoremediation is a green economic method to address soil cadmium (Cd) pollution, and Solanum americanum is considered a potential phytoremediation candidate. However, the underlying Cd response mechanisms of S. americanum remain unclear. In the current study, a hydroponic experiment with 160 μmol/L Cd stress was conducted, physiological and molecular indices were measured to explore the response of S. americanum leaves to Cd stress at different time points (0, 3, and 7 days). Our findings revealed that Cd stress inhibited plant growth. Moreover, Cd stress significantly increased Cd accumulation, as well as Chla content, Chla/b, activities of SOD and POD, and elevated MDA content in the leaves. Furthermore, transcriptomics, proteomics, and metabolomics analyses revealed 17,413 differentially expressed genes (DEGs), 1421 differentially expressed proteins (DEPs), and 229 differentially expressed metabolites (DEMs). Meanwhile, integrative analyses of multi-omics data revealed key proteins involved in response to Cd stress, including POD, PAL, F5H, COMT, and CAD for phenylpropanoid biosynthesis, as well as GAPA, FBP, and FBA for photosynthesis pathways. Additionally, conjoint analyses highlighted that upregulated phenylpropanoid metabolism and photosynthesis alleviated Cd toxicity, playing vital roles in enhancing Cd tolerance in leaves. A conceptual molecular regulatory network of leaves in the response to Cd toxicity was proposed. This comprehensive study will provide detailed molecular-scale insights into the Cd response mechanisms in S. americanum. Full article

Background: Phytoremediation is an efficient approach for remediating heavy metal-contaminated soils. Heavy metal-associated isoprenylated plant proteins (HIPPs)—crucial for metal ion homeostasis—are unique to vascular plants, featuring a heavy metal-associated (HMA) domain and an isoprenylated CaaX motif. However, ZmHIPP genes have not been systematically or functionally characterized in maize. Methods: This study characterizes ZmHIPP at the genome-wide level, including phylogenetic classification, motif/gene structure, chromosome location, gene duplication events, promoter elements, and tissue expression patterns. Cadmium (Cd) responses were evaluated by specific ZmHIPP expression and Cd accumulation in shoots and roots under Cd treatment. Results: A total of 66 ZmHIPPs were distributed unevenly across ten chromosomes, classified into five phylogenetic groups phylogenetically. Gene collinearity revealed 26 pairs of segmental duplications in ZmHIPPs. Numerous synteny genes were detected in rice and sorghum, but none in Arabidopsis, suggesting high conservation of HIPP genes in crop evolution. Transcriptomic analysis revealed tissue-specific expression patterns of ZmHIPP members in maize. Cis-acting element analysis linked several binding elements to abscisic acid, MeJA response, and MYB and MYC transcription factors. Under Cd stress, 53 out of 66 ZmHIPP genes were significantly induced, exhibiting three expression patterns. Cd exposure confirmed that the expression of ZmHIPP11, ZmHIPP30, and ZmHIPP48 was generally higher in shoots than roots, while ZmHIPP02 and ZmHIPP57 exhibited the opposite. Cd accumulation was higher in roots than shoots, peaking at 72 h (96 mg/kg) in shoots and exceeding 1000 mg/kg in roots after 120 h. Conclusions: This study not only provides fundamental genetic and molecular insights into HIPP function in maize but also identifies specific ZmHIPP genes as promising genetic resources for breeding Cd-tolerant maize, aiding in phytoremediation of Cd-contaminated soils. Full article

Cadmium (Cd) contamination in agricultural soils severely threatens rice production and food safety. To address this issue, this study developed transgenic rice lines co-expressing three Vitis vinifera genes: the ABCC transporter Vvmrp1 and metallothioneins Vvmt1 and Vvmt2. AlphaFold computational modeling confirmed the conserved ABCC-type transporter domain in VvMRP1. Under hydroponic conditions, transgenic rice showed remarkable Cd tolerance, surviving 30 mM Cd (lethal to wildtype, WT) without growth penalties, and exhibited 62.5% survival at 1 mM Cd vs. complete wild-type mortality. Field-relevant Cd exposure (1 mM) reduced Cd accumulation to 35.8% in roots, 83% in stems, and 76.8% in grains compared to WT. Mechanistic analyses revealed that Vvmrp1 mediates cellular Cd efflux while Vvmt1 and 2 chelate free Cd ions, synergistically inhibiting Cd translocation. Transgenic plants also maintained better Fe, P, and Mg homeostasis under Cd stress. This study pioneers the co-expression of a transporter with metallothioneins in rice, demonstrating their complementary roles in Cd detoxification without pleiotropic effects from endogenous gene modification. The findings provide an effective genetic strategy for cultivating low-Cd rice in contaminated soils, offering significant implications for food safety and sustainable agriculture. Full article

Cadmium (Cd) significantly influences the morphological, physiological traits, and transport capacity of plants, but the underlying mechanism of Cd stress still remains to be further studied. In this study, physiological, transcriptomic, and metabolomic analyses were conducted to examine the morphological and physiological traits of two elite maize inbred lines, Chang7_2 (C7_2, a Cd-resistant line) and Zheng58 (Z58, a Cd-sensitive line) under control and Cd stress conditions. The results of morphological traits indicated that C7_2 reduced by 9.50–29.60% under Cd stress, whereas Z58 displayed more pronounced morphological changes ranging from 10.12 to 41.72% under Cd stress. Physiological assessments revealed that C7_2 maintained relatively stable antioxidant enzyme activity, while Z58 demonstrated more rapid alterations in the antioxidant system under Cd stress. Transcriptomic analysis identified 3030 differentially expressed genes (DEGs) unique to C7_2 and 4298 DEGs unique to Z58, with 1746 common DEGs shared between the two lines. Functional annotation revealed that the unique DEGs in C7_2 were mainly enriched in plant hormone signal transduction, plant–pathogen interactions, and the MAPK signaling pathway, while the unique DEGs in Z58 were mainly enriched in ribosome-related functions, plant hormone signal transduction, and phenylpropanoid biosynthesis. Metabolomic analysis identified 12 superclasses encompassing 896 metabolites in C7_2 and Z58, primarily including lipids and lipid-like molecules, organic acids and derivatives, as well as organoheterocyclic compounds. Analysis of differentially accumulated metabolites (DAMs) revealed fewer DAMs were accumulated in C7_2 under Cd stress. Further analysis identified that the three pathways of GPI anchor biosynthesis, glycerophospholipid metabolism, and purine metabolism were among the top 10 metabolic pathways in C7_2 and Z58. The integrative analysis highlighted the crucial roles of phenylpropanoid biosynthesis and zeatin biosynthesis in C7_2 for resistance to Cd stress. This study provides novel insights into the molecular and metabolic pathways underlying Cd tolerance in maize by integrating transcriptomic and metabolomic analyses of two contrasting inbred lines, providing a theoretical foundation for the future breeding of Cd-tolerant varieties. Full article

Cadmium (Cd) is a highly hazardous heavy metal that has an extensive impact throughout the world. 2,4-Epibrassinolide (BR) is an endogenous hormone that can enhance plant tolerance to various abiotic stresses. Herein, Vigna angularis cultivar “Zhen Zhuhong” was grown hydroponically and treated with 0, 1, and 2 mg·L⁻¹ cadmium chloride (CdCl₂) at the V1 stage, and foliar sprayed with or without 1 μM BR solution to analyze the effects of BR treatment on the physiology of Vigna angularis seedling leaves under Cd stress. BR treatment significantly alleviated the growth inhibition induced by Cd stress, which was associated with an increase in the plant height (11.15–17.83%), leaf area (35.59–56.72%), leaf dry weight (45.57–50.65%), and above-ground dry weight (50.86–55.17%). In addition, BR treatment induced significant reductions in Cd accumulation across different tissues of V. angularis, with decreases of 20.38–35.93% in leaves, 21.24–32.74% in stems, and 15.38–16.00% in petioles. Compared with the Cd treatment, BR treatment significantly enhanced the activities of peroxidase (5.02–13.22%), ascorbate peroxidase (27.13–70.28%), catalase (20.46–32.30%), and superoxide dismutase (16.54–21.81%), and increased the ascorbic acid content (27.55–45.52%), which contributed to a reduction in the accumulation of reactive oxygen species, cellular membrane damage, and cytoplasmic exosmosis. RNA-seq and real-time quantitative reverse transcription PCR analyses revealed that the BR treatment under Cd stress significantly upregulated the expression of genes involved in chlorophyll biosynthesis, transformation, and degradation, thereby enhancing the chlorophyll cycle. Furthermore, the BR treatment significantly increased the number of grana lamellae in the mesophyll cells, which enhanced the biosynthesis of chloroplasts. The increase in the chlorophyll content improved the capture of light energy, electron transport in photosynthesis, and the biosynthesis and metabolism of carbohydrates in the leaves of V. angularis under Cd stress. Full article

Crop productivity is severely constrained by abiotic and biotic stresses, necessitating innovative strategies to enhance stress resilience. Glycerol-3-phosphate (G3P) is a central metabolite in carbohydrate and lipid metabolism, playing crucial roles in stress responses. In this study, we engineered a novel glycerol-3-phosphate dehydrogenase (GPDH) gene, designated OEGD, by fusing the N-terminal NAD-binding domain of rice OsGPDH1 with the feedback-resistant C-terminal catalytic domain of Escherichia coli gpsA. Overexpression of OEGD in rice enhanced tolerance to drought, phosphorus deficiency, high temperature, and cadmium (Cd²⁺) stresses, while also improving plant growth and yield under drought stress at the adult stage. Notably, the accumulation of glycerol-3-phosphate (G3P) and activities of antioxidant enzymes (SOD, POD, CAT) were significantly elevated in the transgenic plants following osmotic stimuli, and fatty acid profiles were altered, favoring stress adaptation. Transcriptomic analyses revealed that OEGD modulates cell wall biogenesis, reactive oxygen species (ROS) scavenging, and lipid metabolism pathways, with minimal disruption to core G3P metabolic genes. These findings highlight the potential of OEGD as a valuable genetic resource for improving stress resistance in rice. Full article

Cadmium (Cd) contamination in agricultural soils is increasing due to anthropogenic activities, posing a significant threat to plant growth and productivity. Phosphorus (P) has been suggested as a potential mitigator of Cd toxicity, yet the role of cotton genotypes with contrasting low-P tolerance in contaminated soils remains largely unexplored. A hydroponic experiment was conducted to assess the effects of Cd stress (5 μM) on Jimian169 (strong-low-P tolerant) and DES926 (weak-low-P tolerant) cotton genotypes under low-P (0.01 mM KH₂PO₄) and normal P (1 mM KH₂PO₄) conditions. The results revealed that Cd stress, especially under low-P, significantly reduced plant growth, dry matter, photosynthetic rate, and P use efficiency (PUE), while increasing oxidative damage through increased malonaldehyde levels and reactive oxygen species accumulation. These adverse impacts were very much evident in DES926 compared to Jimian169. In contrast, Jimian169 demonstrated greater resilience to Cd stress by mitigating oxidative damage through enhanced antioxidant enzyme activity, improved photosynthetic performance, and increased accumulation of osmoprotectants. These findings indicate that Jimian169 can better withstand Cd toxicity by enhancing photosynthesis, antioxidant defense mechanisms, and osmotic adjustment. This makes them a promising candidate for cultivation in Cd-contaminated, P-deficient soils. Full article

Cadmium (Cd) contamination in soil poses a serious threat to plant growth and productivity, while arbuscular mycorrhizal (AM) fungi play a vital role in enhancing plant growth, improving tolerance to heavy metals, and restoring polluted ecosystems. To enhance the tolerance of Astragalus sinicus to Cd stress, a pot experiment was conducted to investigate the effects of inoculation and copper (Cu) addition on growth, Cd accumulation, and translocation under Cd-stressed soil conditions. The results showed that Cd inhibited the root growth of A. sinicus, and AM fungi inoculation and Cu + AM significantly increased root biomass and root volume (p < 0.05). Under Cd stress, AM fungi inoculation reduced Cd concentration by 72.40% in the shoots, while it increased by 92.69% in the roots. Both AM fungi inoculation and Cu + AM enhanced Cd uptake in the roots, while inhibiting Cd translocation to the shoots. After the application of Cu and inoculation with AM fungi, the roots have a strong absorption and enrichment ability for Cd; the bioconcentration factor of Cd in the roots of A. sinicus reached 1018.59% and 366.08%, respectively. Cu + AM increased the enrichment of Cd in the roots and restricted its translocation to the shoots. Moreover, the combination of AM fungi inoculation and Cu addition significantly increased soluble sugar (by 77.29%) and proline contents (by 445.62%) and reduced CAT activity (by 74.67%) under Cd stress. In summary, both Cu addition and AM fungi inoculation promoted the growth of A. sinicus under Cd stress, improved its physiological metabolism, and reduced Cd content in the soil, with the combined Cu and AM fungi treatment showing the most significant effect. Full article

Cadmium (Cd) contamination in agricultural soils poses a significant threat to human health through the food chain. It is of great significance to address safe wheat production in Cd-contaminated agricultural soils. This study employed foliar spraying of ferulic acid (FA) in both hydroponic and field trials to investigate its potential in alleviating Cd toxicity and reducing Cd accumulation in wheat grains. Our findings revealed that FA application at 20 and 50 μM promoted plant growth, increased photosynthetic efficiency, and enhanced root tolerance to Cd by increasing mean root diameter, surface area, and root tip number, as well as enhancing antioxidant defense in roots. Especially, 20 μM FA foliar application significantly alleviated Cd-induced growth inhibition in seedlings and reduced grain Cd content by 66.3% compared to Cd-stressed alone. Mechanistically, FA downregulated the Cd transporter gene TaHAM2 to reduce Cd translocation from roots to shoots, while upregulated the Cd cellular compartment gene TaHAM3 to increase root Cd retention, of which 82.9% was sequestered in roots. During the grain-filling period in the field trial, FA application reduced Cd transport from roots to stems and stems to rachides, but enhanced Cd retention in rachides and roots. Additionally, FA downregulated the phloem Cd loading gene LCT1, limiting Cd allocation to bracts and grains, which in turn lowered the Cd content in the grains. Collectively, FA foliar application modulated Cd transport pathways by coordinately downregulating xylem and phloem transporter genes and enhancing root Cd retention capacity. These findings established FA as a promising strategy for Cd detoxification and reduced accumulation in crop grains through integrated physiological and molecular interventions. Overall, it holds potential for the future development of safe crop production in soils polluted with Cd. Full article

Cadmium (Cd) is an extremely toxic heavy metal that can move from the soil to plants and enter the human body via the food chain, causing severe health issues for humans. Phytoremediation uses hyperaccumulators to extract heavy metals from polluted soil. Phytohormones, wildly used plant growth regulators, have been explored to improve phytoremediation efficiency. Abscisic acid (ABA) is also an essential regulator of plant tolerance to biotic and abiotic stresses, including heavy metal-induced toxicity. Previous research has revealed that Phytolacca acinosa Roxb. (P. acinosa) has a strong ability to enrich Cd and can be used as a Cd hyperaccumulator. In this study, physiological and biochemical analysis revealed that under Cd stress, exogenous ABA application alleviated oxidative stress, increased the Cd²⁺ concentration in P. acinosa, especially in the roots, and changed the phytohormone concentration in P. acinosa. Transcriptome analysis was conducted to explore the molecular mechanisms by which ABA regulates Cd uptake and accumulation in P. acinosa, and to further understand the regulatory role of ABA. The results show that ABA treatment affected gene expression in P. acinosa roots under Cd stress. This study identified 5788 differentially expressed genes (DEGs) (2541 up-regulated and 3247 down-regulated). Moreover, 96 metal transport-related DEGs, 54 phytohormone-related DEGs, 89 cell wall-related DEGs, 113 metal chelation-related DEGs, and 102 defense system-related DEGs cooperated more closely under exogenous ABA application to regulate Cd uptake and accumulation in P. acinosa under Cd stress. These results may help to elucidate the mechanisms by which ABA regulates Cd uptake and accumulation in plants, and provide a reference for developing a phytohormone-based strengthening strategy to improve the phytoremediation ability of other hyperaccumulators or accumulator species. The key genes involved in ABA’s regulation of Cd uptake and accumulation in P. acinosa need to be further analyzed and functionally verified. This may expand our understanding of the molecular regulatory mechanisms underlying heavy metal uptake and accumulation in hyperaccumulators. Full article

To explore the phytoremediation effect of ornamental chrysanthemums on cadmium (Cd)-contaminated farmland soil, a 2-year field trial was conducted on 23 chrysanthemum cultivars in Cd-contaminated soil in Zhejiang Province, China. The biomass yields, Cd content of the plants, Cd enrichment coefficient, and remediation efficiency were evaluated. The aboveground biomass of the tested chrysanthemums was 67.10–166.08 g/plant, the aboveground Cd content was 1.97–5.92 mg kg⁻¹, and the Cd enrichment coefficient was 2.98–9.84. In a screening test of twenty-three chrysanthemum cultivars, six cultivars, such as marigolds, were characterized by high cadmium accumulation, with the average cadmium accumulation of chrysanthemums exceeding 0.6 mg per plant, and the remediation of rhizosphere-contaminated soils took only 4–5 years. Fourteen chrysanthemum cultivars have good multiple-cropping characteristics, and five multiple-cropping chrysanthemum cultivars, such as QX-yz, have high heavy metal tolerance. The multiple-cropping JL-yg cultivars with higher Cd accumulation could be recommended for the remediation of Cd-contaminated farmland. The application of bamboo vinegar to the chrysanthemum rhizosphere effectively promoted Cd absorption. After estimating the economic benefits of artificially planting five dominant varieties of chrysanthemums for polluted farmland remediation, it is concluded that the annual income of a worker can be slightly higher than the average annual income level of local residents. Full article

To better understand the physiological mechanisms underlying the variation of Cadmium (Cd) accumulation in wheat, Cd absorption, translocation, and distribution in five low grain-Cd-accumulating wheat (LCA) and five high grain-Cd-accumulating wheat (HCA) were studied at four growth stages under three soil Cd concentrations. Grain Cd concentration of HCA was 2.92 times, 1.61 times, and 1.40 times more than that of LCA under the soil with 0.3 mg/kg,1.5 mg/kg, and 7.5 mg/kg Cd concentrations, respectively. LCA was more tolerant of Cd pollution than HCA. Consequently, dry matter in LCA roots, stems + leaves, glumes, grains, and the entire plant was significantly higher than that of HCA at all growth stages under all three soil Cd concentrations, and the most pronounced difference was observed during the maturity stage. The critical period governing the disparity in Cd uptake between LCA and HCA primarily occurred before jointing and the maturity stage. LCA absorbed more Cd than HCA under the three Cd soil concentrations before the jointing stage, during which Cd uptake of LCA was 1.92 times, 1.86 times, and 1.46 times that of HCA under 0.3, 1.5 and 7.5 Cd soil concentrations. But LCA absorbed less Cd than HCA at the maturity stage, during which Cd uptake of LCA was 50%, 50%, and 49% of HCA under 0.3,1.5 and 7.5 mg/kg soil Cd concentrations, respectively. Cd uptake or accumulation per plant in LCA was significantly lower than that of HCA throughout the entire growth period, but the difference between them becomes increasingly smaller as the concentration of Cd contamination increases. Early absorption and accumulation of Cd played a limited role in grain Cd accumulation, and Cd transport played a critical role in determining grain Cd content at maturity. In addition, tolerance to Cd was higher, and grain Cd concentration was lower. Full article

In China, soil contamination by heavy metals is a widespread issue, with substantial increases in lead(Pb), cadmium(Cd), copper(Cu), and zinc(Zn) levels observed across various regions. Particularly, the concentrations of Pb and Cd significantly exceed their natural background levels. P-ATPases, a group of proteins, utilize energy from ATP hydrolysis to support the transmembrane movement of metal ions. This group encompasses several Heavy Metal Associated Transporter (HMA) ATPases. Studies on hyperaccumulators have shown the critical role of HMAs in the movement and reduction in Zn and Cd toxicity in plant systems. This research identifies a protein encoded by the SpHMA gene from Sedum plumbizincicola, a species noted for aiding Zn/Cd hyperaccumulators, which enhances tolerance to Cd and Zn. We detail a protein encoded by SpH/A within the HMA family that enhances Cd tolerance. Real-time fluorescence quantification (RT-PCR) indicates that SpHMA3 expression in Arabidopsis thaliana and Zea mays KN5585 correlates with high Cd tolerance, linked to Cd accumulation in Zea mays. In addition, homozygous Arabidopsis thaliana AtHMA3 mutants exhibited increased Cd sensitivity compared to the wild type (WT). Notably, plants of Arabidopsis thaliana and maize overexpressing SpHMA3 showed enhanced Cd stress tolerance compared to WT. Enhanced Cd accumulation in tissues was observed when SpHMA3 was overexpressed, as revealed by subcellular distribution analysis. We propose that SpHMA3 augments maize tolerance to Cd and Zn stresses through enhanced cellular uptake and translocation of Cd ions. This investigation clarifies the gene function of SpHMA3 in Cd and Zn stress response, offering insights for enhancing heavy metal absorption traits in maize varieties and phytoremediation methods for soils contaminated with heavy metals. Full article