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Phytoremediation coupled with agroproduction (PCA) model contributes to sustainable agriculture and environmental management. This study investigated the impact of continuous cropping early/late season rice (RR) and Sedum alfredii-rice rotation (SR) on soil physical and chemical properties, as well as their relationships with soil microbial community. In 2022, SR treatment significantly increased pH value and organic matter content by 7 % and 17 %, respectively, compared to the levels in 2020, while RR treatment showed no change. RR treatment resulted in a significant decrease in soil concentrations of Ca, Mg, and K by 18.42 %, 29.01 %, and 7.77 %, respectively. Furthermore, SR treatment saw reductions of 29.62 % in total Cd and 38.30 % in DTPA extractable Cd in the soil. Over the two years, both treatments notably influenced the diversity, structure, and network of the rhizosphere bacterial and fungal communities, which are crucial for nutrient cycling and plant health. Notably, SR treatment exhibited a more complex network compared to RR, suggesting a greater impact on the interconnected systems. Therefore, these findings highlight the potential of Sedum rotation system to rehabilitate contaminated soils while supporting agricultural practices, which is essential for food security and environmental sustainability. This research direction holds promise for future exploration and application in the fields of phytoremediation and agroecology.
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Polystyrene nanoplastics (PS NPs) and dibutyl phthalate (DBP) pollution pose significant risks to ecosystems and contribute to bioaccumulation in plants, yet uptake mechanisms and combined toxicity are poorly understood. We used fluorescent labeling and europium-doped PS NPs to reveal the absorption and translocation of NPs by dandelions and conducted a transcriptomic analysis under PS NPs and DBP exposure. The results indicated that NPs are transported horizontally through the intercellular gaps at the root tips and primary root-lateral root junctions via the apoplastic pathway, followed by longitudinal transport through the xylem vessels under the transpiration stream. Co-exposure significantly reduced the bioconcentration factors of dandelion seedlings by 113 % but increased the NP transfer factors by 33.8 %. Transcriptomic analysis confirmed that exposure to PS NPs and DBP activated gene expression in dandelion shoots and roots. The differentially expressed genes were primarily involved in the photosynthesis, plant hormone signal transduction, and phenylpropanoid biosynthesis pathways. Weighted gene co-expression network analysis identified key genes and hub transcription factors playing crucial roles in regulating dandelion's response to combined stress. Our study provides new insights into the plant toxicity mechanism underlying the interaction between PS NPs and DBP, highlighting the adverse effects of the combined pollution on plant health.
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Dibutil Ftalato , Poliestirenos , Taraxacum , Transcriptoma , Dibutil Ftalato/toxicidad , Poliestirenos/toxicidad , Taraxacum/metabolismo , Taraxacum/genética , Contaminantes del Suelo/toxicidad , Contaminantes del Suelo/metabolismo , Raíces de Plantas/metabolismo , Raíces de Plantas/efectos de los fármacosRESUMEN
Biodegradable plastics, such as poly(butylene adipate terephthalate) (PBAT) and polylactic acid (PLA), are potential alternatives to conventional polyethylene (PE), both of which are associated with the production of microplastics (MPs). However, the toxicity of these compounds on medicinal plants and their differential effects on plant morphophysiology remain unclear. This study supplemented soils with MPs sized at 200 µm at a rate of 1% w/w and incubated them for 50 days to investigate the impact of MPs on the growth and metabolites of dandelion (Taraxacum mongolicum Hand.-Mazz.). The results demonstrated that the investigated MPs decreased the growth of dandelion seedlings, induced oxidative stress, and altered the activity of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase). Based on the comprehensive toxicity assessment results, the ecological toxicity was in the following order: PE MPs > PBAT MPs > PLA MPs. Metabolomics analyses revealed metabolic reprogramming in dandelion plants, leading to the enrichment of numerous differentially accumulated metabolites (DAMs) in the leaves. These pathways include carbohydrate metabolism, energy metabolism, and biosynthesis of secondary metabolites, suggesting that dandelions respond to MP stress by enhancing the activity of sugar, organic acid, and amino acid metabolic pathways. In addition, phenolic acids and flavonoids are critical for maintaining the balance in the antioxidant defense system. Our results provide substantial insights into the toxicity of biodegradable MPs to plants and shed light on plant defense and adaptation strategies. Further assessment of the safety of biodegradable MPs in terrestrial ecosystems is essential to provide guidance for environmentally friendly management.
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Microplásticos , Polietileno , Contaminantes del Suelo , Taraxacum , Taraxacum/efectos de los fármacos , Taraxacum/metabolismo , Polietileno/toxicidad , Microplásticos/toxicidad , Contaminantes del Suelo/toxicidad , Contaminantes del Suelo/metabolismo , Metaboloma/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Biodegradación Ambiental , Poliésteres/metabolismo , Plásticos Biodegradables/metabolismo , Antioxidantes/metabolismoRESUMEN
Cadmium is the most prevalent heavy metal pollutant in the environment and can be readily combined with micro/nanoplastics (M/NPs) to change their bioavailability. In the present study, we comprehensively investigated the effect of polystyrene (PS) NPs on dandelion plants grown under Cd stress. Cd exposure significantly inhibited the growth of dandelion seedlings, resulting in a decrease in seedling elongation from 26.47% to 28.83%, a reduction in biomass from 29.76% to 54.14%, and an exacerbation of lipid peroxidation and oxidative stress. The interaction between PS NPs and Cd resulted in the formation of larger aggregates, with the Cd bioavailability reduced by 12.56%. PS NPs affect ion absorption by regulating reactive oxygen production and increasing superoxide dismutase activity, thereby mitigating the adverse effects of Cd. PSCd aggregates induced significant changes in the metabolic profiles of dandelions, affecting various carbohydrates related to alcohols, organic acids, sugar metabolism, and bioactive components related to flavonoids and phenolic acids. Furthermore, based on a structural equation model, exposure to PSCd activated oxidative stress and nutrient absorption, thereby affecting plant growth and Cd accumulation. Overall, our study provides valuable insights into the effects of PS NPs on Cd bioavailability, accumulation, and plant growth, which are crucial for understanding the food safety of medicinal plants in a coexistence environment.
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Antioxidantes , Cadmio , Estrés Oxidativo , Poliestirenos , Plantones , Taraxacum , Cadmio/metabolismo , Cadmio/toxicidad , Poliestirenos/toxicidad , Antioxidantes/metabolismo , Plantones/crecimiento & desarrollo , Plantones/metabolismo , Plantones/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Taraxacum/metabolismo , Taraxacum/efectos de los fármacos , Taraxacum/crecimiento & desarrollo , Nanopartículas/toxicidad , Contaminantes del Suelo/metabolismo , Contaminantes del Suelo/toxicidadRESUMEN
The application of soil amendment (SA) and the cultivation of low Cd-accumulating varieties have been a widely favored strategy to enable the safe utilization of Cd-contaminated arable land. However, little has been reported on the reciprocal effects of SA on the Cd mitigation and nutritional quality of different wheat varieties. In this study, we evaluated the impact of an SA on agronomic traits, Cd accumulation, translocation and mineral nutrition of 12 wheat varieties in an acidic field with a Cd concentration of 0.46 mg/kg. The results showed that the SA significantly reduced soil DTPA Cd (42.3 %) and resulted in a slight decrease in wheat grain yield (4.24-9.72 %, average 7.62 %). Similarly, the SA significantly reduced grain Cd concentrations (average 61.65 %) while increased the concentrations of beneficial elements such as Mo and Se in all wheat varieties. However, this intervention also led to a reduction in the concentration of essential mineral elements (such as Ca, Fe, and Mn) in whole wheat grain and starchy endosperm, as well as a reduction in their proportion in the bran. Based on genotypic differences, Huaimai 33, Zhenmai 168, Sumai 188 and Yangmai 28 were considered to be the relatively most promising wheat varieties for achieving a balance among food safety, nutritional quality, and economic yield in this region. Taken together, this study highlights the varietal differences in Cd mitigation and mineral accumulation in different wheat varieties in response to the SA, offering new perspectives for phytoremediation and biofortification strategies for Cd-contaminated farmland.
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Cadmio , Contaminantes del Suelo , Cadmio/análisis , Suelo , Triticum , Biofortificación , Contaminantes del Suelo/análisis , Minerales , Grano Comestible/químicaRESUMEN
The phytoremediation efficiency of plants in removing the heavy metals (HMs) might be influenced by their growth status and accumulation capacity of plants. Herein, we conducted a lab-scale experiment and a field try out to assess the optimal plant growth regulators (PGRs) including indole-3-acetic acid (IAA)/brassinolide (BR)/abscisic acid (ABA) in improving the phytoextraction potential of Sedum alfredii Hance (S. alfredii). The results of pot experiment revealed that application of IAA at 0.2 mg/L, BR at 0.4 mg/L, and ABA at 0.2 mg/L demonstrated notable potential as optimal dosage for Cd/Pb/Zn phytoextraction in S. alfredii. The findings of subcellular level of Cd/Pb/Zn in leaves showed that IAA (0.2 mg/L), BR (0.4 mg/L) or ABA (0.2 mg/L) promoted the HMs storage in the soluble and cell wall fraction, therefore contributing HMs subcellular compartmentation. In addition, application of PGRs notably enhanced the antioxidant system (SOD, CAT, POD, APX activities) while reducing lipid peroxidation (MDA content) in S. alfredii, consequently improving HMs tolerance and growth of S. alfredii. Moreover, the results of field trial showed that application of BR, IAA, or ABA+BR substantially improved the growth of S. alfredii by inducing plants biomass and augmenting the levels of photosynthetic pigment contents. Notably, ABA+BR noticed the highest theoretical biomass by 42.9 %, followed by IAA (41.6 %), and BR (36.4 %), as compared with CK. Additionally, ABA+BR treatment showed effectiveness in removing the Cd by 103.4 %, while BR and IAA led to a significant increase of Pb and Zn removal by 239 % and 116 %, respectively, when compared with CK. Overall, the results of this study highlights that the foliar application of IAA, BR, or ABA+BR can serve as viable strategy to boosting phytoremediation efficiency of S. alfredii in contaminated soil by improving the biomass and metal accumulation in harvestable parts.
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Metales Pesados , Sedum , Contaminantes del Suelo , Cadmio/análisis , Reguladores del Crecimiento de las Plantas , Plomo , Metales Pesados/análisis , Ácido Abscísico , Biodegradación Ambiental , Suelo , Contaminantes del Suelo/análisis , Raíces de Plantas/químicaRESUMEN
Micro/nanoplastics (M/NPs) and phthalates (PAEs) are emerging pollutants. Polystyrene (PS) MPs and dibutyl phthalate (DBP) are typical MPs and PAEs in the environment. However, how dandelion plants respond to the combined contamination of MPs and PAEs remains unclear. In this study, we evaluated the individual and combined effects of PS NPs (10 mg L-1) and DBP (50 mg L-1) on dandelion (Taraxacum officinale) seedlings. The results showed that compared to control and individual-treated plants, coexposure to PS NPs and DBP significantly affected plant growth, induced oxidative stress, and altered enzymatic and nonenzymatic antioxidant levels of dandelion. Similarly, photosynthetic attributes and chlorophyll fluorescence kinetic parameters were significantly affected by coexposure. Scanning electron microscopy (SEM) results showed that PS particles had accumulated in the root cortex of the dandelion. Metabolic analysis of dandelion showed that single and combined exposures caused the plant's metabolic pathways to be profoundly reprogrammed. As a consequence, the synthesis and energy metabolism of carbohydrates, amino acids, and organic acids were affected because galactose metabolism, the citric acid cycle, and alanine, aspartic acid and glutamic acid metabolism pathways were significantly altered. These results provide a new perspective on the phytotoxicity and environmental risk assessment of MPs and PAEs in individual or coexposures.
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Dibutil Ftalato , Taraxacum , Dibutil Ftalato/análisis , Poliestirenos/toxicidad , Microplásticos/análisis , Biometría , PlásticosRESUMEN
The toxicity of microplastics (MPs) to aquatic organisms has been extensively studied recently. However, few studies have investigated the effects of MPs in sediments on aquatic ecosystem functioning. In the present study, we conducted an in situ experiment to explore the concentration-dependent effects (0.025%, 0.25%, 2.5%) and size-dependent effects (150-300 µm and 500-1000 µm) of polypropylene microplastics (PP MPs) on Vallisneria natans litter decomposition dynamics, in particular, the process associated with macroinvertebrates, microorganisms, as well as microalgae and/or cyanobacteria. The results showed that exposure to high concentrations and large sizes of PP MPs can accelerate leaf litter biomass loss and nutrition release. Moreover, microbial respiration, microalgal and/or cyanobacteria chlorophyll-a were also significantly affected by PP MPs. However, PP MPs have no effect on the abundance of associated macroinvertebrate during the experiment, despite the collection of five macroinvertebrate taxa from two functional feeding groups (i.e., collectors and scrapers). Therefore, our experiment demonstrated that PP MPs may enhance leaf litter decomposition through effected microbial metabolic activity, microalgal and/or cyanobacteria biomass in the sedimentary lake. Overall, our findings highlight that PP MPs have the potential to interfere with the basic ecological functions such as plant litter decomposition in aquatic environments.
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Microalgas , Contaminantes Químicos del Agua , Ecosistema , Microplásticos , Plásticos , Lagos , China , Contaminantes Químicos del Agua/toxicidadRESUMEN
There is a growing body of evidence that suggests that both biodegradable and conventional (non-degradable) microplastics (MP) are hazardous to soil health by affecting the delivery of key ecological functions such as litter decomposition, nutrient cycling and water retention. Specifically, soil fauna may be harmed by the presence of MPs while also being involved in their disintegration, degradation, migration and transfer in soil. Therefore, a comprehensive understanding of the interactions between MPs and soil fauna is essential. Here, we conducted a 120-day soil microcosm experiment applying polyethylene (PE) and polylactic acid (PLA), in the absence/presence of the earthworm Eisenia nordenskioldi to estimate the relative singular and combined impact of MPs and earthworms on the soil bacterial community. Our findings revealed contrasting effects of PE and PLA on the composition and diversity of soil bacteria. All treatments affected the community and network structure of the soil bacterial community. Compared to the control (no MPs or earthworms), PE decreased bacterial alpha diversity, while PLA increased it. Patescibacteria were found to be significantly abundant in the PE group whereas Actinobacteria and Gemmatimonadetes were more abundant in PE, and PLA and earthworms groups. The presence of earthworms appeared to mediate the impact of PE/PLA on soil bacteria, potentially through bacterial consumption or by altering soil properties (e.g., pH, aeration, C availability). Earthworm presence also appeared to promote the chemical aging of PLA. Collectively, our results provide novel insights into the soil-fauna-driven impact of degradable/nondegradable MPs exposure on the long-term environmental risks associated with soil microorganisms.
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Oligoquetos , Polietileno , Animales , Polietileno/toxicidad , Microplásticos , Plásticos , Poliésteres , Bacterias , SueloRESUMEN
Modeling plants for biomass production and metal uptake from surrounding environment is strongly dependent on the moisture content of soil. Therefore, experiments were conducted to find out how soil moisture affects the phenotypic traits, photosynthetic efficiency, metabolic profile, and metal accumulation in the hyperaccumulating ecotype of Sedum alfredii (S. alfredii). A total of six water potential gradients were set: 0 ~ -15 kPa (T1), -15 ~ -30 kPa (T2), -30 ~ -45 kPa (T3), -45 ~ -60 kPa (T4), -60 ~ -75 kPa (T5), and -75 ~ -90 kPa (T6). Different water potential treatments had a significant effect on plant growth and metal uptake efficiency. Compared to T3, T2 was more effective in promoting plant growth and development, with an increase in biomass of 23% and 17% in both fresh weight (FW) and dry weight (DW), respectively. T2 and T3 had the highest cadmium (Cd) content in the shoot (280.2 mg/kg) and (283.3 mg/kg), respectively, whereas T1 had the lowest values (204.7 mg/kg). Cd availability for plants in the soil was affected by moving soil moisture cycles. Changes in soil moisture that were either too high or too low compared to the ideal soil water content for S. alfredii growth resulted in a significant reduction in Cd accumulation in shoots. Tryptophan, phenylalanine, and other amino acids were accumulated in T5, whereas only tryptophan and phenylalanine slightly increased in T1. Sugars and alcohols such as sucrose, trehalose, mannitol, galactinol, and mannobiose increased in T5, while they decreased significantly in T1. Interestingly, in contrast to T1, the two impaired metabolic pathways in T5 (galactose and starch metabolism) were identified to be glucose metabolic pathways. These findings provide scientific information (based on experiments) to improve biomass production and metal uptake efficiency in hyperaccumulating ecotype of S. alfredii for phytoremediation-contaminated agricultural fields.
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Sedum , Contaminantes del Suelo , Cadmio/análisis , Sedum/metabolismo , Ecotipo , Suelo/química , Deshidratación/metabolismo , Triptófano , Contaminantes del Suelo/análisis , Raíces de Plantas/metabolismo , Fotosíntesis , Biodegradación AmbientalRESUMEN
Sustainable strategies are essential for zinc (Zn) biofortification and cadmium (Cd) reduction in staple food crops. Herein, we evaluated the phytotoxicity of Glyzinc under foliar and root application (FA&RA) in a lab-scale experiment, and then investigated its Zn efficiency and Cd reduction through foliar application on wheat (Triticum aestivum L.) under field conditions. Compared to RA, FA of Glyzinc exhibited no adverse effect on wheat growth and oxidative stresses at all doses. In field conditions, FA of Glyzinc remarkably increased Zn (28.7 %), S (10.4 %), Cu (17.3 %) and crude protein (9.1 %) content in wheat grain at 100 mg/L without damaging wheat yield. Furthermore, FA of Glyzinc significantly reduced the grain phytic acid (PA) (23.7 %) and Cd level (19.5 %), as well as PA to Zn molar ratio (32.3 %). Overall, our results indicate that Glyzinc has great potential as a high-efficiency foliar fertilizer for Zn biofortification and safe crop production in nano-enabled agriculture.
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Contaminantes del Suelo , Triticum , Triticum/metabolismo , Fertilizantes , Zinc/análisis , Cadmio/análisis , Biofortificación , Contaminantes del Suelo/análisis , Suelo , Ácido Fítico/metabolismo , Grano Comestible/químicaRESUMEN
Soil organic matter (SOM) is of vital importance to soil health, and also plays a crucial role in the quality of the crops such as tobacco. However, the link between tobacco quality and SOM chemical compositions is still not well understood. To fill the information gap, we analyzed the quality of tobacco leaves and the corresponding SOM molecular compositions by electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), that were collected from six different sites in Bijie, Guizhou Province, China. The tobacco quality variedin six sites based on their chemical compositions. SOM compounds had a remarked impact on the quality of tobacco leaves and a distinct difference in SOM composition between low-quality and high-quality tobacco leaves was observed as well. Specifically, 105 common molecular formulas were detected in three SOM compounds of high-quality tobacco, which were more than those in low-quality samples. Although amino sugar, proteins, lipids, tannins, and carbohydrates had a collective influence on the chemical composition of tobacco leaves, the effect contributed by amino sugar and tannins was more prominent. In summary, fully understanding the association between tobacco chemical composition and SOM compounds can provide new insight into the regulation of tobacco quality and the sustainable development of agriculture.
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Nicotiana , Suelo , Agricultura , Amino Azúcares , Compuestos Orgánicos/análisis , Suelo/química , TaninosRESUMEN
An acidified magnetic sludge-biochar (MSB) was prepared to enhance ammonium nitrogen (AN) removal efficiency in eutrophic water, and MSB was obtained by secondary pyrolysis of sludge biochar powder. A series of MSB were prepared under 300, 400, 500, 600 °C and different valence states of iron ions by impregnation pyrolysis, which is based on the deposition of unstable iron minerals on biochar matrix. Physicochemical properties of pristine biochar and MSB were revealed through characterization analysis, suggesting that MSB prepared by ferric chloride at 400 °C presented the largest adsorption capacity, and the acid-modification enhanced the ammonium adsorption capacity by 10.7%. Electrostatic attraction and ion-exchange processes were identified as the main adsorption mechanisms of MSB on AN. As the most dominant mechanism, ion exchange of AN with functional groups containing -OH and CO on the surface of MSB resulted in the relative content of -OH (61.3%) and CO (11.5%) bonds reduced to 34.2% and 7.0% respectively. The novel magnetic sludge-biochar with acid-modification possessed enhanced electron transfer capacity, revealing a removal pathway of ammonium by nitrification. The findings above demonstrated that MSB is a promising adsorbent for ammonium removal and can be applied to the natural nitrogen-rich water regulation.
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Compuestos de Amonio , Contaminantes Químicos del Agua , Adsorción , Compuestos de Amonio/análisis , Carbón Orgánico , Desnitrificación , Hierro/análisis , Fenómenos Magnéticos , Nitrógeno/análisis , Percepción , Aguas del Alcantarillado , Agua , Contaminantes Químicos del Agua/análisisRESUMEN
Zinc oxide nanoparticles (ZnO NPs) widely used have caught the attention of researchers, nevertheless, phytotoxicity, bioaccumulation, and potential risks thereof to the green leafy still have knowledge defects. A pot experiment was intended to cultivate pakchoi (Brassica chinensis L.) following root exposure to ZnO NPs and Zn2+. ZnO NPs promoted plant growth and Zn accumulation, formed a dose-dependent effect on chlorophyll and carotenoids, and induced fluctuations in antioxidant enzyme activities and alleviated the oxidative damage of pakchoi. Particularly, 1000 mg kg-1 ZnO NPs resulted in malondialdehyde (MDA) content of pakchoi shoots that was 87% higher than control. TEM was used to observe ZnO NPs of root cells and found that its possible way to enter the plant was endocytosis. Research on the content of several co-existing nutrients showed that 100 mg kg-1 ZnO NPs significantly (p < 0.05) promoted the absorption of Ca, P and Fe by pakchoi shoots. In parallel, the hazard quotient (HQ) was used to assess the potential health risk of ZnO NPs.
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Brassica , Nanopartículas , Óxido de Zinc , Bioacumulación , Nanopartículas/toxicidad , Raíces de Plantas , Suelo , Óxido de Zinc/toxicidadRESUMEN
At present, the uptake and accumulation of nanoplastics by plants have raised particular concerns. However, molecular mechanisms underlying nanoplastic phytotoxicity are still vague and insufficient. To address this scientific gap, we analyzed the transcriptome response of hydroponically grown wheat (Triticum aestivum L.) to polystyrene nanoplastics (PSNPs) (100 nm) by integrating the differentially expressed gene analysis (DEGA) and the weighted gene correlation network analysis (WGCNA). PSNPs could significantly shape the gene expression patterns of wheat in a tissue-specific manner. Four candidate modules and corresponding hub genes associated with plant traits were identified using WGCNA. PSNPs significantly altered carbon metabolism, amino acid biosynthesis, mitogen-activated protein kinase (MAPK) signaling pathway-plant, plant hormone signal transduction, and plant-pathogen interaction Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. In addition, some Gene Ontology (GO) terms associated with the metal ion transport were further screened. These findings shed new light on the phytotoxic mechanism and environmental implication behind the interaction of nanoplastics and crop plants, and advance our understanding of the potential adverse effect induced by the presence of nanoplastics in agricultural systems.
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Microplásticos , Triticum , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Poliestirenos/toxicidad , Transcriptoma , Triticum/genéticaRESUMEN
Microfibers (MFs) and cadmium (Cd) are widely distributed in soil ecosystems, posing a potential threat to soil biota. To explore potential risks of single MFs and in combination with Cd (co-PMFs/Cd) to soil environment, we systematically investigated the effects of PMFs and co-PMFs/Cd treatments on physio-biochemical performance and metabolomic profile of lettuce (Lactuca sativa), as well as the rhizospheric bacterial communities. Our results showed that both PMFs and co-PMFs/Cd treatments adversely disturbed the plant shoot length, photosynthetic, and chlorophyll content. Co-PMFs/Cd specifically increased the activities of antioxidant enzymes. The metabolites in lettuce leaf were significantly altered by PMFs and co-PMFs/Cd treatments. A significant reduction in the relative abundance of amino acids sugar and sugar alcohols indicated the altered nitrogen and carbohydrates related metabolic pathways. Additionally, PMFs and co-PMFs/Cd treatments altered the structure of rhizospheric bacterial communities and caused significant changes in some key beneficial/functional bacteria involved in the C, and N cycles. The present study provides a novel insight into the potential effects of PMFs on plant and rhizosphere bacterial communities and highlights that PMFs can threaten the terrestrial ecosystem and should be further explored in future research.
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Microbiota , Contaminantes del Suelo , Cadmio/análisis , Cadmio/toxicidad , Lactuca , Poliésteres , Suelo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidadRESUMEN
To explore the pollution status of heavy metals and potential risks in the Yongding New River of Tianjin, China, a comparative study of concentrations of heavy metals (Cd, Cr, Cu, Pb, Zn, As, and Hg) in surface sediments from submerged areas (SA), fluctuant flooded district (FFD), and non-flooded district (NFD) was conducted. In the present study, a modified three-stage European Community Bureau of Reference sequential extraction procedure and EDTA-Na2 single extraction were used to determine the heavy metal distribution in different sediment samples. Results showed that Cd was the metal with the highest contamination level compared to a background value of Tianjin soils, particularly in SA, followed by As. The concentrations of Cr, Pb, Cu, and Zn were relatively higher in upstream. Cu and Pb had higher bioavailability when compared with the other metals, indicating the two metals were easier to be mobilized. The Pearson correlation coefficient is applied to assess the degree of correlation between heavy metals. As, Cu, Zn, and Hg had the strong correlation, implying they may have common sources. Human activity in the riparian such as agricultural production, vehicle, and burning coal increased inputs of heavy metals in the surface sediments and influenced their distribution spatially. Besides, we also calculated geo-accumulation indexes (Igeo) and eco-risk index to assess the degree of risk of heavy metals in sediments. The Igeo were higher in SA than in FFD and NFD. Based on Igeo and potential eco-risk index, Cd has the highest risk, followed by As and Hg.
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Metales Pesados , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Sedimentos Geológicos , Humanos , Metales Pesados/análisis , Medición de Riesgo , Ríos , Agua , Contaminantes Químicos del Agua/análisisRESUMEN
Currently, there is a lack of information about the influence of foliar-applied nanoplastics on crop growth and nutritional quality. To fill the knowledge gap, soil-grown lettuces (Lactuca sativa L.) were foliar-exposed to polystyrene nanoplastics (PSNPs) at 0, 0.1 and 1 mg/L for one month. Foliar exposure to PSNPs significantly decreased the dry weight, height, and leaf area of lettuce by 14.3%-27.3%, 24.2%-27.3%, and 12.7%-19.2%, respectively, compared with the control. Similarly, plant pigment content (chlorophyll a, b and carotenoid) was considerably reduced (9.1%, 8.7%, 12.5%) at 1 mg/L PSNPs. However, the significant increase in electrolyte leakage rate (18.6%-25.5%) and the decrease in total antioxidant capacity (12.4%-26%) were the key indicators of oxidative stress in lettuce leaves, demonstrating the phytotoxicity of PSNPs by foliar exposure. In addition, the remarkable reduction in micronutrients and essential amino acids demonstrated a decrease in nutritional quality of lettuce caused by PSNPs. Besides, SEM and TEM analysis indicated the possible absorption of PSNPs through leaves stoma and the translocation downwards to plant roots. This study provides new information about the interaction of airborne NPs with plants. It also warns against atmospheric NPs pollution that the adverse effects of airborne NPs on crop production and food quality should be assessed as a matter of urgency.
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Lactuca , Poliestirenos , Clorofila A , Microplásticos , Valor Nutritivo , Hojas de la PlantaRESUMEN
To reduce cadmium (Cd) pollution of food chains, screening and breeding of low-Cd-accumulating genotypes have received increasing attention. However, the mechanisms involving Cd tolerance and accumulation are not fully understood. Here, we investigated the physiological responses and metabolomics profiling on two wheat (Triticum aestivum L.) genotypes, a low-Cd-accumulating genotype in grains (Aikang58, AK58) and a high-Cd-accumulating genotype in grains (Zhenmai10, ZM10), in hydroponic culture treated without/with Cd for 7 days. The results showed that AK58 was a Cd tolerant genotype with higher capacity of antioxidant systems in root. In addition, the concentrations of Cd bound to root cell walls were higher in AK58 than ZM10, of which pectin and hemicellulose played important roles in Cd binding. Moreover, subcellular distribution manifested that Cd sequestrated in the vacuoles was another tolerance mechanism in AK58. Simultaneously, metabolomics profiling showed that, in AK58, phenylalanine metabolism, alanine, aspartate and glutamate metabolism, isoquinoline alkaloid biosynthesis, arginine and proline metabolism, arginine biosynthesis and glyoxylate and dicarboxylate metabolism are highly related to antioxidant defense system, cell wall biosynthesis and metabolisms of phytochelatins together with other organic ligands, playing crucial roles in Cd tolerance and Cd fixation mechanisms in roots. These novel findings should be useful for molecular assisted screening and breeding of low Cd-accumulating genotypes for wheat crop.
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Cadmio , Contaminantes del Suelo , Cadmio/análisis , Genotipo , Metabolómica , Fitomejoramiento , Raíces de Plantas/química , Contaminantes del Suelo/análisis , Triticum/genéticaRESUMEN
Continuous cropping obstacle (CCO) is a common phenomenon in agricultural production and extremely threatens the sustainable development of agriculture. To clarify the potential keystone factors causing tobacco (Nicotiana tabacum L.) CCO, tobacco plants, topsoil, and rhizosphere soil were sampled from the fields with no, slight, and severe tobacco disease in Dali and Yuxi of Yunnan province in China. The physicochemical properties of topsoil and rhizosphere soil, the phenolic acids (PAs) contents in rhizosphere soil, and elemental contents in topsoil, rhizosphere soil, and tobacco plants were analyzed. Microbial diversity in rhizosphere soil was determined by the metagenomic sequencing method. The results showed that soil pH, texture, cation exchange capacity, organic matter, TC, TN, and available K contents showed a significant difference (p < 0.05) in soil physicochemical properties. There was a deficiency of B, K, Mg, and Mn contents in soil and/or tobacco plants. The contents of PAs, especially syringic acid in rhizosphere soil, varied significantly among the three sampling groups (p < 0.05). Meanwhile, microbial communities and functional genes changed from beneficial to harmful, showing an intimate correlation with soil pH and syringic acid content. It can be concluded that tobacco CCO could be allocated to the imbalance of soil micro-ecology, which possessed a regional feature at the two sampling sites.