Cd has high activity and bioavailability and is a poisonous element to plants. As a critical ecosysterm, mangroves are subjected to serious Cd pollution. In this research, the hypothesis was ...presented that improving Fe bioavailability would alleviate Cd phytotoxicity to Avicennia marina (Forsk.) Vierh. To test this, we examined the effect of four exogenous Fe and three Cd concentrations on A. marina. The results showed that a significant positive correlation excited between moderate exogenous Fe concentration and Cd tolerance of A. marina. Moderate exogenous Fe concentration directly or indirectly promoted the formation of Fe plaque, which immobilised more Cd on the root surface and decreased Cd absorption in roots. Furthermore, an exogenous Fe application increased plant biomass and Fe accumulation in A. marina tissues. This improved the competition between Fe and Cd within the plants. Therefore, an Fe application facilitated a decrease in Cd toxicity within A. marina. Simultaneously, a moderate Fe concentration caused an increase in low-molecular-weight organic acid (LMWOA) secretion from the roots. Meanwhile, Cd can be chelated/complexed by LMWOAs. It also played a crucial role in Cd detoxification in A. marina. In conclusion, Fe application accelerated the growth and enhanced Cd tolerance of A. marina. Therefore, improving Fe bioavailability will protect mangroves from Cd contamination.
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•Fe promoted Fe plaque to immobilise more Cd and decrease Cd absorption.•Fe improved competition between Fe and Cd, and facilitated a decrease in Cd toxicity.•Fe caused LMWOA secretion increase and played a crucial role in Cd detoxification.•Significant positive correlation existed between Fe concentration and Cd tolerance.•Fe application accelerated the growth and enhanced Cd tolerance of A. marina.
Improving Fe bioavailability would alleviate Cd phytotoxicity to mangrove plants.
Sensitive and rapid analysis of zearalenone (ZEN) in grains and feed is essential to guarantee the food security for human health. Herein a chemiluminescence method was demonstrated to measure the ...content of zearalenone in food samples. An immunomagnetic beads-anti-ZEN monoclonal antibody complex was prepared. Besides, the immunomagnetic beads were utilized as the solid support for rendering the immunoassay through the rapid formation of immune complexes in the solution, rapid separation and efficient heterogeneous detection. Under the optimal experimental parameters, the standard curve of ZEN detection is
y
= − 0.3839x + 0.1565 (
R
2
= 0.9978), the signal ratio has a well linear relationship with the logarithm of ZEN concentration in the range of 0.03–2.43 ng/mL. The limit detection of zearalenone in the developed assay was 0.01 ng/mL. The applicability of the reported approach for zearalenone detection in grains was demonstrated. In addition, the good recoveries of zearalenone were obtained, ranging from 85.15 to 102.60% at 5, 50, 150 ng/g spiked ZEN concentrations. The relative standard deviation was < 10%. The proposed chemiluminescence immunoassay is sensitive, simple, rapid and reliable for monitoring of zearalenone contamination, which provides a powerful avenue for further application of other mycotoxin in food analysis.
Copper oxide nanoparticles (CuO NPs) were regarded as the versatile materials in daily life and the in-depth evaluation of their biological effects is of great concern. Herein the female and male ...zebrafishes were chosen as the model animals to analyze the reproductive toxicity caused by CuO NPs at low concentration (10, 50 and 100 μg/L) After 20-days exposure, the structure of zebrafish ovary and testis were impaired. Moreover, the contents of 17β-estradiol (E2) in both females and males were increased, while the contents of testosterone (T) were decreased, indicating the imbalanced sex hormones caused by CuO NPs. The expression of genes along the hypothalamic pituitary-gonad (HPG) axis, were examined with quantitative real-time PCR to further evaluate the toxic mechanisms. Meanwhile, the levels of erα/er2β and cyp19a in female zebrafishes and erα/er2β, lhr, hmgra/hmgrb, 3βhsd and 17βhsd in male zebrafishes were obviously up-regulated. While, the level of αr was obviously down-regulated in female and male zebrafishes. Thus, the obtained data uncovered that long-term exposure of CuO NPs with low dose could trigger the endocrine disorder, resulting in the disturbance of E2 and T level, inhibition of gonad development, and alteration of HPG axis genes. In brief, this study enriched the toxicological data of NPs on aquatic vertebrates and provided the theoretical support for assessing the environmental safety of NPs.
●The reproductive system of female and male zebrafishes were damaged by CuO NMs at low dose.●Pathological lesions of ovaries and testis was triggered, accompanied with the disturbed level of E2 and T.●The alteration of HPG axis genes (e.g., erα/er2β, cyp19a, lhr, hmgra/hmgrb, 3βhsd/17βhsd, αr) reinforced the nanotoxicity.
In this study, a sensitive high-performance liquid chromatography method for zearalenone determination in feeds and grains was established based on the automatic immunomagnetic bead purifier analyzer ...(KY-AMI-I) for the one-step sample pre-treatment. Various parameters that may affect the analytical performance were investigated. Immunomagnetic bead separation system based on a monoclonal antibody (anti-ZEN antibody-immunomagnetic beads conjugation) was individually prepared for the ZEN purification. Besides, the average recoveries in spiked samples ranged from 75.23 to 102.62%, and the relative standard deviations were between 3.55 and 8.07% (< 10%). The method was used to analyze naturally contaminated positive feedstuff, and the results obtained by this method was in a good agreement with data obtained by immunoaffinity column-high-performance liquid chromatography (IAC-HPLC–FLD). The conformity and correlation of two methods was satisfactory. The comprehensive results showed that the proposed method was shown to be a suitable method for ZEN determination.
Growth behavior of different species under different habitats can be studied by comparing the production of biomass, plasticity index and relative competitive interaction. However, these functional ...traits of invasive species received rare consideration for determining the invasion success of invasive species at wetlands. Here, we examined the effect of water depth at 5 cm and 15 cm (static and fluctuated) with different nutrient concentrations (full-strength (n1), 1/4-strength (n2) and 1/8-strength (n3) Hoagland solution) on functional traits of invasive Wedelia trilobata and its congener native Wedelia chinensis under mono and mixed culture. Water depth of 5 cm with any of the nutrient treatments (n1, n2 and n3) significantly restrained the photosynthesis, leaf nitrogen and photosynthetic nitrogen use efficiency (PNU
) of both W. trilobata and W. chinensis. While, increase in the water depth to 15 cm with low nutrient treatment (n3) reduced more of biomass of W. chinensis under mixed culture. However, relative competition interaction (RCI) was recorded positive for W. trilobata and seemingly W. trilobata benefited more from RCI under high-fluctuated water depth at 15 cm in mixed culture. Therefore, higher PNU
, more competitive ability and higher plasticity may contribute to the invasiveness of W. trilobata in wetlands.
Biochar shows unique advantage in decreasing the bioavailability of phenanthrene and has huge potential into the in-situ remediation of contaminated sediment. The different order spiking influences ...the bioavailability and ecological risk of phenanthrene, this study provides a comprehensive investigation of biochar (derived from mangrove Kandelia obovata -sediment system under three conditions: I) co-addition of biochar and sediment; II) biochar and subsequently sediment addition (after biochar adsorption reached equilibrium); III) sediment and subsequently biochar addition (after sediment adsorption reached equilibrium). It was observed that the adsorption capability under model I and III was much smaller than that under model II (p < 0.05). Regardless of time, K. obovate - biochar significantly (p < 0.05) increase the sorption of phenanthrene in sediment -water system. The results provide valuable studies for further in-situ remediation of phenanthrene and engineering applications.
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•Different order spiking of PAH influences its PAH sorption onto biochar.•PAH bioavailability is limited by biochar addition that lowers PAH sorption.•With sediment first, PAH diffusion into biochar-inter-sites reduce its desorption.•PAH inter-phase transport involve pore-filling theory and exterior surface sites.
The molecular mechanisms underlying allelopathy and their role in the interactions between invasive weeds and native species remain unclear. In this study, we aimed to explore the physiological and ...molecular response of plant roots of a native species to allelopathy from an invasive weed. We examined the growth and development of roots of native
Arabidopsis thaliana
for a 2-week period after being treated with aqueous extracts at different concentrations from invasive
Conyza canadensis
. Extracts with higher concentration in the Murashige and Skoog (MS) media (i.e., 4 mg of extract/mL of MS) significantly affected the root growth of
A. thaliana
. Roots of
A. thaliana
displayed weakened root tip activity and an accumulation of reactive oxygen species (ROS) in response to extracts from
C. canadensis
. The transcriptome analysis of
A. thaliana
roots exposed to phytotoxicity revealed differentially expressed genes (DEGs) involved in cell wall formation, abiotic stress, transporter genes and signal transduction. We found that genes associated with nutrient transport, such as major facilitator superfamily (MFS) and amino acid permease (AAP3) transporters as well as genes involved in stress response, including leucine-rich repeat receptor-like protein kinases (LRR-RLKs) were down-regulated. In addition, we found that many transcription factors associated with plant stress (such as APETALA2/ethylene response factors) were up-regulated while others (e.g., zinc-finger proteins) were down-regulated. Allelochemicals from
C. canadensis
also induced the up-regulation of detoxification (DTX) genes, ROS related genes, calcineurin B-like interacting protein kinases (CIPKs) and calmodulin. Overall, our findings provided insights into allelopathy in
C. canadensis
at the molecular level, and contributes to our understanding of invasion mechanisms of alien plant species.
Clinical trials registration
This study does not contain any studies with clinical trials performed by any of the authors.
Molybdenum disulfide nanomaterials (MoS2 NMs) have shown significant role as photocatalysts, lubricating agents and sterilant due to their remarkable physicochemical properties. Because of the ...increasing demand for MoS2 NMs in numerous industrial domains, greater occupational exposure and subsequent NMs release into environment would be unavoidable. However, much efforts have been made to uncover the biological effects of NMs at unrealistic high concentration or acute duration, placing constraints on setting the realistic occupational exposure thresholds with confidence. In order to fill the current knowledge gap, this study aimed to evaluate the nanotoxicity of MoS2 NMs with or without surface defects under the more realistic exposure mode. Noteworthily, the artificial sweat transformed-occupational exposure-cytotoxicity investigation of MoS2 NMs was established as the main studied line. And the high cellular internalization and augmented oxidative stress triggered by surface defect could be recognized as the main factors for triggering serious cellular damage. Moreover, the HaCaTs exhibited loss of cell membrane integrity, dysfunction of mitochondria, disorder of endoplasmic reticulum and damages of nuclei after chronic exposure, compared with acute exposure. The study provided closely realistic exposure scenarios for NMs which exhibited significant difference from acute toxic investigation, enriching understanding towards real environmental safety of NMs.
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•The study provided real toxic investigation of MoS2 with or without defects.•The sweat transformed - occupational exposure - toxicity investigation was established as studied line.•Higher toxicity was triggered by sweat transformed MoS2 after chronic exposure than acute exposure.•High internalization and oxidative damage caused by defect were main factors for serious nanotoxicity.•The function of main organelles and cellular defense were disturbed after occupational exposure.
Allelochemicals released by exotic plants can affect neighboring plants. In this study, we examined the effects of leachate extracted from shoots of an invasive clonal plant (
Wedelia trilobata
) on ...its own growth and performance, and that of its native congener (
W. chinensis
). Leachate from
W. trilobata
was prepared at concentrations of 0, 50, 75, and 100% and was applied to both
Wedelia
species (which were grown in mono and mixed culture). We monitored the effects of the leachate on plant growth, physiological traits, and relative competition intensity (RCI) in each species. Leachate concentration significantly affected the majority of growth and physiological traits in both species. Higher leachate concentrations significantly increased most traits of
W. trilobata
under mono and mixed culture
.
In contrast, many growth and physiological parameters in
W. chinensis
were significantly reduced in response to higher concentrations of leachate. Growth and physiological traits were higher in
W. trilobata
than
W. chinensis
at higher leachate concentrations in both mono and mixed culture. In
W. trilobata,
RCI significantly increased with increasing leachate concentration. However, RCI in
W. chinensis
remained consistently low in response to higher leachate concentrations. Overall, the addition of leachate from invasive
W. trilobata
had a strong allelopathic effect on native
W. chinensis
under mono and mixed culture. Conversely, growth and competitive ability in
W. trilobata
was enhanced in response to the leachate. Thus, allelochemicals from
W. trilobata
promote its own performance while simultaneously suppressing that of a native congener, which has likely contributed to its invasion success.
Co-invasion by two invasive plant species (IPS) can occur in the same habitat. Diversified acid deposition may change the co-invasion process by altering litter decomposition and plant-soil feedback ...signalling. This study examined the co-decomposition of two Asteraceae IPS (Solidago canadensis L. and Bidens pilosa L.) on litter decomposition rate, soil enzyme activities, and soil N-fixing bacterial communities under diversified acid deposition (mixed acid deposition at pH 5.6 and at pH 4.5, sulfuric acid at pH 4.5, and nitric acid at pH 4.5). B. pilosa litter degraded faster than S. canadensis litter. Acid deposition at higher acidity accelerated the decomposition rate of both pure S. canadensis litter and the equally mixed litters from the two Asteraceae IPS. Antagonistic responses may occur during the co-decomposition of the two Asteraceae IPS with mixed acid deposition, regardless of the pH, as well as with nitric acid deposition at pH 4.5; in contrast, there may be neutral responses for the co-decomposition process with sulfuric acid at pH 4.5. The type of acid deposited may be one of the key factors affecting the intensity of the mixing effect affecting the co-decomposition. Acid deposition at higher acidity weakened the antagonistic responses for the co-decomposition of the two Asteraceae IPS compared with the response to weak acids. Together, these results indicate that acid deposition at higher acidity could facilitate the co-invasion of the two Asteraceae IPS mainly through accelerated litter decomposition as well as weakened antagonistic responses for co-decomposition.
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