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Sodium sulfate stress is known to improve cadmium (Cd) mobilization in soil and microbial sulfur oxidation, Cd resistance, and the accumulation of stress tolerance-associated metabolites has been correlated with increased soil Cd availability and toxicity. In this study, aerobic soil microcosms with Cd-contamination were stimulated with sodium sulfate to investigate its effects on soil microbial community structure, functional genes, and associated metabolite profiles. Metagenomic analysis revealed that sulfur oxidizing and Cd-resistant bacteria carried gene clusters encoding sox, dsr, and sqr genes, and znt, czc, and cad genes, respectively. Exposure to sodium sulfate resulted in the reprogram of soil metabolites. In particular, intensification of sulfur metabolism triggered an up-regulation in the tricarboxylic acid (TCA) cycle, which promoted the secretion of carboxylic acids and their precursors by soil bacteria. The accumulation of organic acids induced in response to high sodium sulfate dosages potentially drove an observed increase in Cd mobility. Pseudomonas and Erythrobacter spp. exhibited a high capacity for adaptation to heavy metal- or sulfur-induced stress, evident by an increased abundance of genes and metabolites for sulfur cycling and Cd resistance. These results provide valuable insights towards understanding the microbial mechanisms of sulfur transformation and Cd dissolution under saline stress.
Meng Wang; Lifu Wang; Huading Shi; Yongbing Liu; Shibao Chen. Soil bacteria, genes, and metabolites stimulated during sulfur cycling and cadmium mobilization under sodium sulfate stress. Environmental Research 2021, 201, 111599 .
AMA StyleMeng Wang, Lifu Wang, Huading Shi, Yongbing Liu, Shibao Chen. Soil bacteria, genes, and metabolites stimulated during sulfur cycling and cadmium mobilization under sodium sulfate stress. Environmental Research. 2021; 201 ():111599.
Chicago/Turabian StyleMeng Wang; Lifu Wang; Huading Shi; Yongbing Liu; Shibao Chen. 2021. "Soil bacteria, genes, and metabolites stimulated during sulfur cycling and cadmium mobilization under sodium sulfate stress." Environmental Research 201, no. : 111599.
Periodic flooding in paddy soils impacts redox behavior and induces variations in pe+pH levels. Manganese (Mn) is capable of reducing cadmium (Cd) uptake by rice. However, the processes involved in how Mn alters Cd mobilization under different pe+pH environments remain poorly understood. To investigate the mechanisms of Mn-mediated soil Cd-stabilization and subsequent inhibition of Cd uptake from flooded soils, we examined Cd immobilization in soil pot incubations, transcriptional changes in Cd-transport genes, and metabolomic analyses of roots and rhizosphere soils with or without Mn application. We found a decrease in extractable Cd concentration largely depended on irrigation-associated low pe+pH, exogenous Mn enhancement of Fe−Mn (oxyhydro)oxide-mediated Cd transformation, and Cd deposition in rice Fe/Mn plaques. Mn application led to striking effects on the expression of Cd-related genes eg. IRT, HMA, and NRAMP in rice root tissue. Exposure to Mn under variable pe+pH levels resulted in metabolic reprogramming of soil and rice roots. Mn induced amino acid synthesis in rice roots, leading to rhizosphere accumulation of free L-lysine, glycine, and glutamine, which can reportedly bind metal ions, forming complexes with Cd. Thus, secreted amino acids, low pe+pH, and free Mn can together comprise a multi-faceted approach to managing Cd toxicity in rice.
Meng Wang; Lifu Wang; Shuwen Zhao; Shanshan Li; Xiaoqin Lei; Luyao Qin; Xiaoyi Sun; Shibao Chen. Manganese facilitates cadmium stabilization through physicochemical dynamics and amino acid accumulation in rice rhizosphere under flood-associated low pe+pH. Journal of Hazardous Materials 2021, 416, 126079 .
AMA StyleMeng Wang, Lifu Wang, Shuwen Zhao, Shanshan Li, Xiaoqin Lei, Luyao Qin, Xiaoyi Sun, Shibao Chen. Manganese facilitates cadmium stabilization through physicochemical dynamics and amino acid accumulation in rice rhizosphere under flood-associated low pe+pH. Journal of Hazardous Materials. 2021; 416 ():126079.
Chicago/Turabian StyleMeng Wang; Lifu Wang; Shuwen Zhao; Shanshan Li; Xiaoqin Lei; Luyao Qin; Xiaoyi Sun; Shibao Chen. 2021. "Manganese facilitates cadmium stabilization through physicochemical dynamics and amino acid accumulation in rice rhizosphere under flood-associated low pe+pH." Journal of Hazardous Materials 416, no. : 126079.
Salt stress can cause significant changes to soil microbial community structure, metabolic processes, and the surrounding micro-environments. However, how these processes affect the availability of cadmium (Cd) remains poorly understood. Changes in soil microbial communities within different soil micro-environments (large-, macro-, small-aggregate and silt plus clay fractions) and their metabolic responses to saline stress in Cd contaminated soils were analyzed. Salt addition negatively affected the stability of soil aggregates and promoted Cd translocation from large soil aggregates into smaller clay/silt sized fractions. Comparatively, soil bacteria were more sensitive than fungi in their responses to salt addition, as more prominent variations in bacterial community structure were observed between AS (added salt) and CK (no added salt) treatments, determined via non-metric multidimensional scaling analysis. Both bacteria and fungi showed greater diversity and richness in microaggregate fractions than in large aggregates, and salt addition decreased overall alpha diversity and altered microbial community composition. Among the node taxa, Sphingomonadaceae, Pyrinomonadaceae, Nitriliruptoraceae, Bacillaceae, Halomonadaceae and Pseudomonadaceae likely played critical roles in mediating Cd availability in soil micro-environments under saline stress. Furthermore, exposure to salt stress resulted in soil microbe metabolic reprogramming. The accumulation of tricarboxylic acid (TCA) cycle components and membrane lipid metabolites potentially contributed to observed increases in soil Cd availability and microbial Cd resistance.
Meng Wang; Shuwen Zhao; Lifu Wang; Shibao Chen; Shanshan Li; Xiaoqin Lei; Xiaoyi Sun; Luyao Qin. Salt stress-induced changes in microbial community structures and metabolic processes result in increased soil cadmium availability. Science of The Total Environment 2021, 782, 147125 .
AMA StyleMeng Wang, Shuwen Zhao, Lifu Wang, Shibao Chen, Shanshan Li, Xiaoqin Lei, Xiaoyi Sun, Luyao Qin. Salt stress-induced changes in microbial community structures and metabolic processes result in increased soil cadmium availability. Science of The Total Environment. 2021; 782 ():147125.
Chicago/Turabian StyleMeng Wang; Shuwen Zhao; Lifu Wang; Shibao Chen; Shanshan Li; Xiaoqin Lei; Xiaoyi Sun; Luyao Qin. 2021. "Salt stress-induced changes in microbial community structures and metabolic processes result in increased soil cadmium availability." Science of The Total Environment 782, no. : 147125.
The purpose of this study was to examine the efficacy of the algicidal bacterium Sagittula stellata on the cell lysis of Nannochloropsis oceanica, a microalga found in the marine environment, in order to extract intracellular valuables. Algicidal bacteria are capable of lysing algal cell walls while keeping lipids and proteins intact yet separated. We obtained these microbes from locations with consistent algae blooms and found that the bacterium Sagittula stellata displayed significant algicidal properties toward Nannochloropsis oceanica, achieving an algicidal rate of 80.1%. We detected a decrease of 66.2% in in vivo fluorescence intensity in algae cultures, obtained a recoverable crude lipid content of 23.3% and a polyunsaturated fatty acid (PUFA) ratio of 29.0% of bacteria-treated algae, and observed the lysis of the cell membrane and the structure of the nucleus of algae. We also identified the inhibited transcription of the ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (rbcS) gene and proliferating cell nuclear antigen (PCNA)–related genes and the upregulated heat shock protein (hsp) gene in algal cells during bacterial exposure. Our results indicate that Sagittula stellata effectively lysed microalgae cells, allowing the recovery of intracellular valuables. The algicidal method of Sagittula stellata on Nannochloropsis oceanica cells was confirmed to be a direct attack (or predation), followed by an indirect attack through the secretion of extracellular algicidal compounds. This study provides an important framework for the broad application of algicidal microorganisms in algal cell disruption and the production of intracellular valuables.
Meng Wang; Wen Qiao Yuan; Shibao Chen; Lifu Wang; Shuwen Zhao; Shanshan Li. Algal Lysis by Sagittula stellata for the Production of Intracellular Valuables. Applied Biochemistry and Biotechnology 2021, 193, 2516 -2533.
AMA StyleMeng Wang, Wen Qiao Yuan, Shibao Chen, Lifu Wang, Shuwen Zhao, Shanshan Li. Algal Lysis by Sagittula stellata for the Production of Intracellular Valuables. Applied Biochemistry and Biotechnology. 2021; 193 (8):2516-2533.
Chicago/Turabian StyleMeng Wang; Wen Qiao Yuan; Shibao Chen; Lifu Wang; Shuwen Zhao; Shanshan Li. 2021. "Algal Lysis by Sagittula stellata for the Production of Intracellular Valuables." Applied Biochemistry and Biotechnology 193, no. 8: 2516-2533.
Effect of Fe redox state caused by low soil pe+pH levels on Cd uptake by rice is unclear. Rice grown in pots of Cd-contaminated paddy soil were subjected to different irrigation regimes: flooding, intermittent flooding (Int-FL), and sustained soil moisture at 70% water holding capacity (WHC). Results showed low pe+pH (5.52 and 7.09) in flooding treatment significantly increased relative abundances of Fe-reducing bacteria (FeRB) (6.29% and 4.51%), especially members within the Clostridium, Geobacter and Desulfuromonadia genera. Stimulation of FeRB activity induced Fe(III) reduction and increased Fe2+ content in flooded soils, which promoted Cd sequestration in low-crystalline fraction of IP (IP-Feh-Cd) and Cd bonded to amorphous Fe-oxides (amFeox-Cd). The 24.9%-62.4% higher amFeox-Cd content was the important factor for 20.4%–44.2% lower CaCl2-extractable Cd content in flooding treatment than those in other treatments. Soil submergence reduced Cd uptake by rice at tillering and booting stages, the critical periods of Cd transport in the soil-rice system, which was attributed to the increases in dissolved Fe2+ and IP-Feh-Cd contents and decrease in CaCl2-Cd content. Therefore, maintaining flooding during the tillering and booting stages may be an effective strategy to reduce Cd uptake by rice cultivated in Cd-contaminated soil.
Shanshan Li; Xiaoqin Lei; Luyao Qin; Xiaoyi Sun; Lifu Wang; Shuwen Zhao; Meng Wang; Shibao Chen. Fe(III) reduction due to low pe+pH contributes to reducing Cd transfer within a soil-rice system. Journal of Hazardous Materials 2021, 415, 125668 .
AMA StyleShanshan Li, Xiaoqin Lei, Luyao Qin, Xiaoyi Sun, Lifu Wang, Shuwen Zhao, Meng Wang, Shibao Chen. Fe(III) reduction due to low pe+pH contributes to reducing Cd transfer within a soil-rice system. Journal of Hazardous Materials. 2021; 415 ():125668.
Chicago/Turabian StyleShanshan Li; Xiaoqin Lei; Luyao Qin; Xiaoyi Sun; Lifu Wang; Shuwen Zhao; Meng Wang; Shibao Chen. 2021. "Fe(III) reduction due to low pe+pH contributes to reducing Cd transfer within a soil-rice system." Journal of Hazardous Materials 415, no. : 125668.
The objective of this study was to explore potential microbial mechanisms associated with how water management may alter soil Cd availability under changing pe + pH environments. Four water regimes, aerobic [70% MWHC] + dissolved oxygen, aerobic, continuous flooding, and continuous flooding + N2, were applied to Cd-contaminated soil. The results show that the anoxic treatments were effective in decreasing soil pe + pH and in turn decreased Cd availability and increased soil S and Fe availability relative to those of the aerobic treatments. The decreased pe + pH enriched some anaerobic microorganisms such as those in the families Anaerolineaceae and Geobacteraceae. Conversely, other families, such as Gemmatimonadaceae and Sphingomonadaceae, appeared to be sensitive biomarkers that responded to aerobic treatments. Bacterial community structure and network interactions were altered to strengthen bacterial responses to different pe + pH environments as indicated by phylogenetic molecular ecological network (pMEN) analysis. The majority of predicted functional categories, such as metabolism, cell motility, and membrane transport, were affected by different irrigation regimes as indicated by a functional gene profile analysis. The categories were related to important traits that facilitated acclimation of bacteria to their local environment with altered soil pe + pH. Structural equation models revealed that soil pe + pH contributed significantly to soil enzyme activities and differences in bacterial community and function, and consequently, was responsible for the variation of soil Cd availability and iron or sulfur reduction.
Meng Wang; Shibao Chen; Li Chen; Duo Wang. Microbial mechanisms responsible for the variation of soil Cd availability under different pe+pH environments. Ecotoxicology and Environmental Safety 2020, 206, 111057 .
AMA StyleMeng Wang, Shibao Chen, Li Chen, Duo Wang. Microbial mechanisms responsible for the variation of soil Cd availability under different pe+pH environments. Ecotoxicology and Environmental Safety. 2020; 206 ():111057.
Chicago/Turabian StyleMeng Wang; Shibao Chen; Li Chen; Duo Wang. 2020. "Microbial mechanisms responsible for the variation of soil Cd availability under different pe+pH environments." Ecotoxicology and Environmental Safety 206, no. : 111057.
In this study, the effect of unstable pe + pH levels on the transformation of Fe oxides in different-sized soil fractions and its impact on Cd speciation were explored. Paddy soil samples collected from two locations in China were cultivated for two months under one of four pe + pH conditions: flooding + N2 (T1), flooding (T2), 70% water holding capacity (T3), and 70% water holding capacity + O2 (T4). Chemical analysis and X-ray diffraction (XRD) were used to identify the mineralogical phases and species of Fe and Cd in paddy soils. The results show that the decrease of soil pe + pH level favored the transformation of well-crystallized Fe oxides (Fec), such as hematite and goethite, into poorly-crystallized (Feo) and organically-complexed (Fep) forms. The transformation promoted the binding of Cd to Fe oxides and was primarily responsible for up to a 41.8% decrease of soil DTPA (diethylenetriaminepentaacetic acid)-extractable-Cd content. In addition, the decline in pe + pH value reduced Fe concentrations in soil particle fractions of 0.2–2-mm (17.8%–30.6%) and <0.002-mm (20.7%–31.7%) of the two flooding treatments. The decreased Fe concentrations were closely associated with less Fec contents in these same fractions and more Feo and Fep in coarser aggregates (P < 0.01). Importantly, the increase in contents of Feo and Fep in the 0.002–2 mm fraction were significantly correlated with content of Fe-/Mn-oxide-bound Cd (OX-Cd) in larger particle-size fractions (P < 0.01). Furthermore, the increasing content of OX-Cd played a crucial role in reducing DTPA-Cd content. This study demonstrates that low pe + pH values favor the transformation of crystalline Fe oxides into a poorly-crystallized and organically-complexed phase, which facilitates Cd accumulation in coarser aggregates and enhances Cd stability in paddy soils.
Shanshan Li; Shibao Chen; Meng Wang; Xiaoqin Lei; Han Zheng; Xiaoyi Sun; Lifu Wang; Yun Han. Redistribution of iron oxides in aggregates induced by pe + pH variation alters Cd availability in paddy soils. Science of The Total Environment 2020, 752, 142164 .
AMA StyleShanshan Li, Shibao Chen, Meng Wang, Xiaoqin Lei, Han Zheng, Xiaoyi Sun, Lifu Wang, Yun Han. Redistribution of iron oxides in aggregates induced by pe + pH variation alters Cd availability in paddy soils. Science of The Total Environment. 2020; 752 ():142164.
Chicago/Turabian StyleShanshan Li; Shibao Chen; Meng Wang; Xiaoqin Lei; Han Zheng; Xiaoyi Sun; Lifu Wang; Yun Han. 2020. "Redistribution of iron oxides in aggregates induced by pe + pH variation alters Cd availability in paddy soils." Science of The Total Environment 752, no. : 142164.
Iron (Fe) in soil is closely related to cadmium (Cd) uptake by rice plants, and soil pe + pH significantly influences Fe redox behavior. This study aimed to explore the influential mechanisms of varying pe + pH conditions on the transformation of iron oxides in the rhizosphere and the subsequent effect on Cd accumulation in rice plants. A two-month pot experiment was conducted to investigate the effect of soil pe + pH on the fractions of iron oxides and formation of iron plaque (IP), as well as the effect of these changes on Cd uptake by rice plants (Oryza sativa L.). Different irrigation strategies, 70% water holding capacity (DY), continuous flooding (FL), and alternate flooding/drying weekly (AWD), were used to achieve various soil pe + pH levels. The results showed that low pe + pH conditions (under the FL and AWD treatments) were more beneficial to the transformation of crystalline iron oxides into amorphous forms in rhizosphere soil and the precipitation of IP on rice roots. The increase of amorphous iron oxides resulted in the reduction of Cd availability in rhizosphere soil by immobilizing more Cd on Fe oxides. Moreover, Cd adsorbed on rice root surfaces reacted with IP, inhibiting Cd soil-to-root transport. The two mechanisms combinatively functioned at decreasing Cd concentration in rice shoots by 14.1–33.1% at low pe + pH conditions compared to that of the high pe + pH (DY treatment). These results indicate that lowering soil pe + pH effectively reduced Cd accumulation in rice plants, probably through the immobilization of amorphous Fe oxides on Cd and sequestration of iron-plaque on Cd.
Shanshan Li; Shibao Chen; Meng Wang; Xiaoqin Lei; Han Zheng; Xiaoyi Sun; Lifu Wang; Yun Han. Iron fractions responsible for the variation of Cd bioavailability in paddy soil under variable pe+pH conditions. Chemosphere 2020, 251, 126355 .
AMA StyleShanshan Li, Shibao Chen, Meng Wang, Xiaoqin Lei, Han Zheng, Xiaoyi Sun, Lifu Wang, Yun Han. Iron fractions responsible for the variation of Cd bioavailability in paddy soil under variable pe+pH conditions. Chemosphere. 2020; 251 ():126355.
Chicago/Turabian StyleShanshan Li; Shibao Chen; Meng Wang; Xiaoqin Lei; Han Zheng; Xiaoyi Sun; Lifu Wang; Yun Han. 2020. "Iron fractions responsible for the variation of Cd bioavailability in paddy soil under variable pe+pH conditions." Chemosphere 251, no. : 126355.
Long-term wastewater irrigation impacts soil geochemical properties (salinity, pH and soil aggregates) and promotes the bioaccumulation of heavy metals to plants, which may change soil function, decrease soil health, decrease the productivity of farmland, and even cause land degradation. In this study, we explored the impact of saline stress on soil bacterial communities and Cd availability in long-term wastewater-irrigated field soil. Different amounts of saline stress by adding 0.1, 0.3 and 0.5% salts in a fixed proportion (NaCl: Na2SO4: NaHCO3: Na2CO3 = 1:9:9:1) were applied in a 1-year, multiple cropping system with winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) in wastewater-polluted soil. Increased salinity in the soil increased Cd availability: compared with CK (no extra salts addition), addition of 0.5% mixed salts significantly increased soil available Cd up by 67.5% and grain Cd concentration by 43.7%, and adding 0.5% salts also resulted in the increases of soil pH (∼0.5 unit) and electric conductivity (97.4%). Soil saline stress significantly changed major soil microbes in Cd-contaminated soil. Increased saline stress enriched taxa in the Bacillaceae, Staphylococcaceae and Pseudomonadaceae bacterial families, while one family within Proteobacteria (Sphingomonadaceae) was the most sensitive biomarker, based on Cd contamination without saline stress in CK-treated soils. Structural equation modeling (SEM) analysis revealed that soil saline stress induced an increase in soil Cd availability that was regulated by the bacterial community.
Meng Wang; Shibao Chen; Li Chen; Duo Wang; Chunmei Zhao. The responses of a soil bacterial community under saline stress are associated with Cd availability in long-term wastewater-irrigated field soil. Chemosphere 2019, 236, 124372 .
AMA StyleMeng Wang, Shibao Chen, Li Chen, Duo Wang, Chunmei Zhao. The responses of a soil bacterial community under saline stress are associated with Cd availability in long-term wastewater-irrigated field soil. Chemosphere. 2019; 236 ():124372.
Chicago/Turabian StyleMeng Wang; Shibao Chen; Li Chen; Duo Wang; Chunmei Zhao. 2019. "The responses of a soil bacterial community under saline stress are associated with Cd availability in long-term wastewater-irrigated field soil." Chemosphere 236, no. : 124372.
The objective of this study was to investigate the responses of cadmium (Cd) availability and transfer in the soil-rice system to added sulfur (S) under unstable pe + pH conditions. Different water management conditions (flooding and aerobic treatments) cause changes in the soil pe + pH. We conducted a pot experiment to investigate the influence of S supply on soil Cd availability and Cd accumulation in rice plants (Oryza sativa L.), using three water regimes (continuous dryness, alternating dry-wet for one cycle, and continuous flooding) combined with two S concentrations (0 and 300 mg/kg). The results showed that the flooding treatment was more effective in decreasing soil pe + pH, Cd availability, and Cd accumulation in rice tissues than were the aerobic treatments. S-induced reduction in Cd uptake and translocation in rice was attributed to the decreased soil pe + pH values and enhanced biosynthesis of phytochelatins (PCs) and glutathione (GSH) in rice roots. Microscopic examination showed that the flooding treatment with added soil S resulted in better rice root growth. Element dispersive spectrometer (EDS) analysis indicated that S addition and flooding treatment promoted the formation of iron plaques and increases in Fe concentration in rice tissues. Conversely, partial disintegration of the root epidermis was observed in the dry treatment without added S.
Han Zheng; Meng Wang; Shibao Chen; Shanshan Li; Xiaoqin Lei. Sulfur application modifies cadmium availability and transfer in the soil-rice system under unstable pe+pH conditions. Ecotoxicology and Environmental Safety 2019, 184, 109641 .
AMA StyleHan Zheng, Meng Wang, Shibao Chen, Shanshan Li, Xiaoqin Lei. Sulfur application modifies cadmium availability and transfer in the soil-rice system under unstable pe+pH conditions. Ecotoxicology and Environmental Safety. 2019; 184 ():109641.
Chicago/Turabian StyleHan Zheng; Meng Wang; Shibao Chen; Shanshan Li; Xiaoqin Lei. 2019. "Sulfur application modifies cadmium availability and transfer in the soil-rice system under unstable pe+pH conditions." Ecotoxicology and Environmental Safety 184, no. : 109641.
An eight-year field trial was conducted to investigate the effects of four different N fertilization treatments of urea (CO(NH2)2, the control), ammonium sulfate ((NH4)2SO4), ammonium chloride (NH4Cl), and ammonium hydrogen phosphate [(NH4)2HPO4]) on cadmium (Cd) phytotoxicity in rice and soil microbial communities in a Cd-contaminated paddy of southern China. The results demonstrate that the different N treatments exerted different effects: the application of (NH4)2HPO4 and (NH4)2SO4 significantly increased rice grain yield and decreased soil-extractable Cd content when compared with those of the control, while NH4Cl had a converse effect. Expression of genes related to Cd uptake (IRT and NRAPM genes) and transport (HMA genes) by roots may be responsible for Cd phytotoxicity in rice grown in the different N fertilization treatments. Our results further demonstrate that N fertilization had stronger effects on soil bacterial communities than fungal communities. The bacterial and fungal keystone species were identified by phylogenetic molecular ecological network (pMEN) analysis and mainly fell into the categories of Gammaproteobacteria, Acidobacteria and Actinobacteria for the bacterial species and Ascomycota for the fungal species; all of these keystone species were highly enriched in the (NH4)2HPO4 treatment. Soil pH and soil available-Cd content emerged as the major determinants of microbial network connectors. These results could provide effective fertilizing strategies for alleviating Cd phytotoxicity in rice and enhance the understanding of its underlying microbial mechanisms.
Meng Wang; Shibao Chen; Han Zheng; Shanshan Li; Li Chen; Duo Wang. The responses of cadmium phytotoxicity in rice and the microbial community in contaminated paddy soils for the application of different long-term N fertilizers. Chemosphere 2019, 238, 124700 .
AMA StyleMeng Wang, Shibao Chen, Han Zheng, Shanshan Li, Li Chen, Duo Wang. The responses of cadmium phytotoxicity in rice and the microbial community in contaminated paddy soils for the application of different long-term N fertilizers. Chemosphere. 2019; 238 ():124700.
Chicago/Turabian StyleMeng Wang; Shibao Chen; Han Zheng; Shanshan Li; Li Chen; Duo Wang. 2019. "The responses of cadmium phytotoxicity in rice and the microbial community in contaminated paddy soils for the application of different long-term N fertilizers." Chemosphere 238, no. : 124700.
The objective of this study was to examine the response of soil archaeal communities to saline stress in different types of Cd-contaminated soils from the North China Plain. Increased soil salinity by addition of 0.5% sodium salts (NaCl: Na2SO4: NaHCO3: Na2CO3 = 1:9:9:1) increased available Cd concentration, resulting in decreased ratios of Cd2+/CdT and CdSO4/CdT and increased ratios of CdCln2−n/CdT in soil solution. Soil saline stress decreased archaeal abundance and diversity and changed major soil archaeal taxa. For example, increased saline stress enriched taxa in the archaeal phyla Thaumarchaeota and Euryarchaeota, and these enriched tolerant taxa had much stronger correlations with soil properties, such as soil pH, EC or Na+. In addition, some microbes with low abundances like Bathyarchaeia (no rank) and Candidatus Nitrosotenuis were found to closely correlate with soil pH, EC, Na+, and Cl−, indicating they might play disproportionate roles in regulating ecological functions in stressed habitats. These results suggest that saline stress modified the effect of Cd toxicity on soil archaeal communities in different types of Cd-contaminated soils.
Meng Wang; Shibao Chen; Li Chen; Duo Wang. Saline stress modifies the effect of cadmium toxicity on soil archaeal communities. Ecotoxicology and Environmental Safety 2019, 182, 109431 .
AMA StyleMeng Wang, Shibao Chen, Li Chen, Duo Wang. Saline stress modifies the effect of cadmium toxicity on soil archaeal communities. Ecotoxicology and Environmental Safety. 2019; 182 ():109431.
Chicago/Turabian StyleMeng Wang; Shibao Chen; Li Chen; Duo Wang. 2019. "Saline stress modifies the effect of cadmium toxicity on soil archaeal communities." Ecotoxicology and Environmental Safety 182, no. : 109431.
Land degradation by salinization and sodification changes soil function, destroys soil health, and promotes bioaccumulation of heavy metals in plants, but little is known about their fundamental mechanisms in shaping microbial communities and regulating microbial interactions. In this study, we explored the impact of saline-alkaline (SA) stress on soil bacterial and fungal community structures in different Cd-contaminated soils of Dezhou, Baoding, Xinxiang, Baoding and Shenyang cities from the North China Plain, China. Increased soil salinity and alkalinity enhanced Cd availability, indicated by significant increases in available Cd2+ in soil solution of 34.1%–49.7%, soil extractable Cd of 32.0–51.6% and wheat root Cd concentration of 24.5%–40.2%, as well as decreased activities of antioxidative enzymes of wheat root when compared with CK (no extra neutral or alkaline salts added). Soil bacteria were more active in response to the SA stress than fungi, as the significant structural reorganization of soil bacterial microbiota rather than fungal microbiota between SA and CK treatments was illustrated by principal component analysis. Adding neutral and alkaline salts enriched oligotrophic and haloalkaliphilic taxa in the Sphingobacteriaceae, Cellvibrionaceae, and Caulobacteraceae bacterial families, but decreased some Acidobacteria such as subgroup 6_norank, which was a sensitive biomarker that responded only to Cd contamination in CK-treated soils. Conversely, fungi were more sensitive to soil differences than bacteria: the composition of the fungal community was significantly different among different soil types. Phylogenetic molecular ecological network (pMEN) analysis further indicated that the microbial community structure and network interactions were altered to strengthen the adaptability of microorganisms to SA stress; the changes in structure and network interactions were proposed to contribute to competitive interactions. Most of the keystone genera identified in SA-treated soils, such as Blastococcus, Gemmatimonas, RB41, or Candida, had relatively low abundances (<1%), indicating their disproportionate ecological roles in triggering resistance or tolerance to SA stress and Cd toxicity.
Meng Wang; Shibao Chen; Li Chen; Duo Wang. Responses of soil microbial communities and their network interactions to saline-alkaline stress in Cd-contaminated soils. Environmental Pollution 2019, 252, 1609 -1621.
AMA StyleMeng Wang, Shibao Chen, Li Chen, Duo Wang. Responses of soil microbial communities and their network interactions to saline-alkaline stress in Cd-contaminated soils. Environmental Pollution. 2019; 252 ():1609-1621.
Chicago/Turabian StyleMeng Wang; Shibao Chen; Li Chen; Duo Wang. 2019. "Responses of soil microbial communities and their network interactions to saline-alkaline stress in Cd-contaminated soils." Environmental Pollution 252, no. : 1609-1621.
The objectives of this study were to investigate the response of cadmium (Cd) distribution and stability in soil aggregates as affected by applying different amendments and to understand the relationship between changes in soil aggregates and alleviation of Cd phytotoxicity to rice after amendment application. In the present study, rice (Oryza sativa L.) was cultivated on a Cd-polluted soil. Five soil amendments were applied, which are as follows: rice husk biochar (BC), Fe-added rice husk biochar (Fe-BC), attapulgite-based mixture (AM), zeolite-based mixture (ZM), and cow manure-based mixture (MM). The effect on Cd redistribution in soil and Cd accumulation in rice plant was evaluated. The results showed that the five amendments applied at the rate of 3% (w/w) significantly increased soil pH and decreased Cd mobility in soil and Cd accumulation in rice plants. The reduction rate of Cd content in rice grains ranged from 41 to 62% after amendment application. The remediation efficiency of the different amendments for decreasing Cd accumulation in rice tissues followed the order of Fe-BC > MM > BC > ZM > AM. Adding amendments promoted the formation of large aggregates (0.2–2.0 mm) with more mass loading of Cd and enhanced aggregate stability. Comparatively, Fe-BC was more effective than others for remediation of acid Cd-polluted paddy soil, as a significantly decreased Cd concentration in rice grain after its application was observed. Structural equation modeling (SEM) analysis revealed that DTPA-extractable Cd in small aggregates was the main factor affecting Cd accumulation in rice grain; soil pH directly affected aggregate stability; and aggregate stability was closely related to Cd availability in different size soil particles. These results indicated that the applied amendments were effective in reducing Cd bioavailability, most likely through raising the soil pH, improving aggregate stability, and re-distributing Cd from smaller soil aggregates to larger ones.
Shanshan Li; Meng Wang; Zhongqiu Zhao; Xiaoyue Li; Shibao Chen. Use of soil amendments to reduce cadmium accumulation in rice by changing Cd distribution in soil aggregates. Environmental Science and Pollution Research 2019, 26, 20929 -20938.
AMA StyleShanshan Li, Meng Wang, Zhongqiu Zhao, Xiaoyue Li, Shibao Chen. Use of soil amendments to reduce cadmium accumulation in rice by changing Cd distribution in soil aggregates. Environmental Science and Pollution Research. 2019; 26 (20):20929-20938.
Chicago/Turabian StyleShanshan Li; Meng Wang; Zhongqiu Zhao; Xiaoyue Li; Shibao Chen. 2019. "Use of soil amendments to reduce cadmium accumulation in rice by changing Cd distribution in soil aggregates." Environmental Science and Pollution Research 26, no. 20: 20929-20938.
The objective of this study was to investigate how soil aggregates and bacterial communities responded to soil-lead (Pb) immobilization induced by biofertilizer. Wheat (Triticum spp.) was planted in Pb-polluted soil. The re-distribution of Pb in soil aggregates and change of soil microbial communities due to biofertilizers were believed to be responsible for immobilizing soil Pb and alleviating its phytotoxicity. Adding biofertilizer promoted the formation of large aggregates (0.20–2.0 mm) with more mass loading of Pb, and increased soil bacterial diversity and the abundance of beneficial taxa such as those from the phyla Bacteroidetes, Actinobacteria, and Proteobacteria. In addition, there was significant alleviation of Pb availability as indicated by decreases in the values of bioconcentration factors (BCF) (up to 35.7% and 42.3% for roots and shoots, respectively) of wheat and DTPA-extractable Pb in soil (up to 34.4%) receiving fertilizer treatments compared with the CK (no treatment). Similar bacterial community structures and alpha diversities for the biofertilizer treatments and their autoclaved controls were observed, suggesting that physicochemical properties drove the structure of the soil bacterial community. This study introduced a new idea for development of effective strategies to control or reduce soil Pb risks.
Meng Wang; Shibao Chen; Yun Han; Li Chen; Duo Wang. Responses of soil aggregates and bacterial communities to soil-Pb immobilization induced by biofertilizer. Chemosphere 2019, 220, 828 -836.
AMA StyleMeng Wang, Shibao Chen, Yun Han, Li Chen, Duo Wang. Responses of soil aggregates and bacterial communities to soil-Pb immobilization induced by biofertilizer. Chemosphere. 2019; 220 ():828-836.
Chicago/Turabian StyleMeng Wang; Shibao Chen; Yun Han; Li Chen; Duo Wang. 2019. "Responses of soil aggregates and bacterial communities to soil-Pb immobilization induced by biofertilizer." Chemosphere 220, no. : 828-836.
Melatonin is a multifunctional signaling molecule that regulates broad aspects of responses to environmental stresses in plants. Cadmium (Cd) is a persistent soil contaminant that is toxic to all living organisms. Recent reports have uncovered the protective role of melatonin in alleviating Cd phytotoxicity, but little is known about its regulatory mechanisms in plants. In this study, we found that foliar application of melatonin (in particular 100 μmol L−1) remarkably enhanced Cd tolerance of tobacco (Nicotiana tabacum L.) leaves, as evidenced by less Cd accumulation and alleviation of growth inhibition and photoinhibition, compared with nontreated Cd-stressed plants. The addition of melatonin also controlled oxidative damage of Cd on tobacco through direct scavenging and by enhancing the activities of antioxidative enzymes. Melatonin application promoted Cd sequestration in the cell wall and vacuoles based on the analysis of subcellular distribution of Cd in tobacco cells. Structural equation modeling (SEM) analysis revealed that melatonin-induced Cd tolerance in tobacco leaves was modulated by the expression of Cd-transport genes. Molecular evidence illustrated that modulation of IRT1, Nramp1, HMA2, HMA4, and HMA3 genes caused by melatonin could be responsible for weakening Cd uptake, Cd transportation to xylem, and intensifying Cd sequestration into the root vacuoles.
Meng Wang; Shuhui Duan; Zhicheng Zhou; Shibao Chen; Duo Wang. Foliar spraying of melatonin confers cadmium tolerance in Nicotiana tabacum L. Ecotoxicology and Environmental Safety 2018, 170, 68 -76.
AMA StyleMeng Wang, Shuhui Duan, Zhicheng Zhou, Shibao Chen, Duo Wang. Foliar spraying of melatonin confers cadmium tolerance in Nicotiana tabacum L. Ecotoxicology and Environmental Safety. 2018; 170 ():68-76.
Chicago/Turabian StyleMeng Wang; Shuhui Duan; Zhicheng Zhou; Shibao Chen; Duo Wang. 2018. "Foliar spraying of melatonin confers cadmium tolerance in Nicotiana tabacum L." Ecotoxicology and Environmental Safety 170, no. : 68-76.
Tobacco leaves usually accumulate and concentrate high levels of cadmium (Cd) when growing in contaminated soil, and the transfer of Cd through tobacco smoke to human body could cause serious health risks. In this study, we explored the impact of biofertilizers on alleviating Cd-induced growth inhibition of tobacco leaves. Tobacco (Nicotiana tabacum L.) was planted in three naturally Cd-polluted soils from Chinese main tobacco-planting areas. Adding biofertilizer alleviated Cd-induced degradation of tobacco leaves quality, represented by the balanced K, Cl, N, nicotine or sugar contents and their ratios; Cd reduction rate of tobacco leaves was increased and soil extractable Cd was decreased, when compared with CK (no extra biofertilizer addition). The following changing tendencies were believed to be responsible for immobilizing soil Cd and alleviating its toxicity to tobacco leaves: the re-distribution of Cd from the fraction of smaller soil aggregates to the fraction of larger soil aggregates; and the shift of major soil microbes by increasing the abundance of beneficial taxa such as those from the phyla Actinobacteria, Proteobacteria or Chloroflexi. In all biofertilizer treatments, the effectiveness in mitigating Cd toxicity to tobacco leaves was dependent on the type of biofertilizer and soil applied. This study provides a feasible way to control or reduce Cd toxicity for sustainable tobacco production.
Meng Wang; Shuhui Duan; Zhicheng Zhou; Shibao Chen. Alleviation of cadmium toxicity to tobacco (Nicotiana tabacum) by biofertilizers involves the changes of soil aggregates and bacterial communities. Ecotoxicology and Environmental Safety 2018, 169, 240 -247.
AMA StyleMeng Wang, Shuhui Duan, Zhicheng Zhou, Shibao Chen. Alleviation of cadmium toxicity to tobacco (Nicotiana tabacum) by biofertilizers involves the changes of soil aggregates and bacterial communities. Ecotoxicology and Environmental Safety. 2018; 169 ():240-247.
Chicago/Turabian StyleMeng Wang; Shuhui Duan; Zhicheng Zhou; Shibao Chen. 2018. "Alleviation of cadmium toxicity to tobacco (Nicotiana tabacum) by biofertilizers involves the changes of soil aggregates and bacterial communities." Ecotoxicology and Environmental Safety 169, no. : 240-247.
The objective of this study was to understand the effect of biofertilizers on cadmium (Cd)-induced phytotoxicity and the rhizosphere bacterial community. The crop specie rice (Oryza sativa L.) was planted in Cd-contaminated soils, and Illumina high-throughput sequencing was performed to investigate how the composition of the rhizosphere bacterial community responded to the addition of biofertilizers. Biofertilizers were effective in alleviating Cd phytotoxicity as indicated by the significant increase in plant biomass (up to 85.2% and 48.4% for roots and shoots, respectively) and decrease in tissue Cd concentration (up to 72.2% in roots) of rice receiving fertilizer treatments compared with the CK (no treatment). These positive effects were likely due to the increase in soil pH, which can be attributed primarily to Cd immobilization, and the promotion of beneficial taxa such as Proteobacteria, Bacteroidetes, Gemmatimonadetes, and Firmicutes. In addition, autoclaved biofertilizers tended to have similar beneficial effects and similar bacterial community alpha diversities as the original biofertilizer treatments. This suggests that the change in soil physicochemical properties by biofertilizer addition might drive the structure of rhizosphere bacterial community, and not the biofertilizer microbes themselves. In both the original and sterilized biofertilizer treatments, the effectiveness in mitigating of Cd phytotoxicity was found to be dependent on the type of biofertilizer applied. Comparatively, the biofertilizer denoted as DY was more effective in mitigating Cd phytotoxicity than others. These results demonstrate that biofertilizer addition could be a promising approach to immobilize soil Cd by manipulating the rhizosphere bacterial community, thus to facilitate plant growth.
Meng Wang; Shanshan Li; Shibao Chen; Nan Meng; Xiaoyue Li; Han Zheng; Chunmei Zhao; Duo Wang. Manipulation of the rhizosphere bacterial community by biofertilizers is associated with mitigation of cadmium phytotoxicity. Science of The Total Environment 2018, 649, 413 -421.
AMA StyleMeng Wang, Shanshan Li, Shibao Chen, Nan Meng, Xiaoyue Li, Han Zheng, Chunmei Zhao, Duo Wang. Manipulation of the rhizosphere bacterial community by biofertilizers is associated with mitigation of cadmium phytotoxicity. Science of The Total Environment. 2018; 649 ():413-421.
Chicago/Turabian StyleMeng Wang; Shanshan Li; Shibao Chen; Nan Meng; Xiaoyue Li; Han Zheng; Chunmei Zhao; Duo Wang. 2018. "Manipulation of the rhizosphere bacterial community by biofertilizers is associated with mitigation of cadmium phytotoxicity." Science of The Total Environment 649, no. : 413-421.
In China, 1/5 of the total farmland area is Cd-enriched; the wide occurrence of Cd-contaminated soil in China has already posed significant public health risk and deserves immediate action. In situ immobilization has been regarded as one of the most promising agricultural extension-technologies for remediating low-to-medium levels of heavy metal contaminated land in China. Although extensive research has been conducted to examine the effectiveness of different amendments on remediation of Cd-contaminated soils, the influence of changed soil properties on secondary release of Cd from Cd-amendment to soil is rarely known. The objective of this study was to evaluate the effectiveness of four soil amendments (denoted as Ad1, Ad2, Ad3 and Ad4, their main components being clay mineral, base mineral, humus and biochar, respectively) on reducing Cd availability and increasing Cd stability in soil. The maximum adsorption capacity of test amendments on Cd ranged from 7.47 to 17.67 mg g−1. The characterizations of test amendments before and after Cd loading provided the evidence that surface precipitation and ion exchange were the main reasons for Ad1 and Ad2 to adsorb Cd, and complexation was for Ad3 and Ad4. In addition, there was significant increase in the desorption percentages of Cd from amendments as pH decreased (from 7 to 1) or ion strength increased (from 0 to 0.2 M). Comparatively, Ad3 and Ad4 could be more effective for in situ immobilization of Cd in contaminated soils, due to their high adsorption capacities (12.82 and 17.67 mg g−1, respectively) and low desorption percentages (4.46–6.23%) at pH from 5 to 7 and ion strengths from 0.01 to 0.1 mol L−1. The results obtained in this study could provide a guideline for in-situ remediation of Cd polluted field-soil in China.
Shanshan Li; Meng Wang; Zhongqiu Zhao; Changbao Ma; Shibao Chen. Adsorption and Desorption of Cd by Soil Amendment: Mechanisms and Environmental Implications in Field-Soil Remediation. Sustainability 2018, 10, 2337 .
AMA StyleShanshan Li, Meng Wang, Zhongqiu Zhao, Changbao Ma, Shibao Chen. Adsorption and Desorption of Cd by Soil Amendment: Mechanisms and Environmental Implications in Field-Soil Remediation. Sustainability. 2018; 10 (7):2337.
Chicago/Turabian StyleShanshan Li; Meng Wang; Zhongqiu Zhao; Changbao Ma; Shibao Chen. 2018. "Adsorption and Desorption of Cd by Soil Amendment: Mechanisms and Environmental Implications in Field-Soil Remediation." Sustainability 10, no. 7: 2337.
Soil aggregates exert a significant influence on the retention and bioavailability of Cd in soil.
Shanshan Li; Meng Wang; Zhongqiu Zhao; Xiaoyue Li; Yun Han; Shibao Chen. Alleviation of cadmium phytotoxicity to wheat is associated with Cd re-distribution in soil aggregates as affected by amendments. RSC Advances 2018, 8, 17426 -17434.
AMA StyleShanshan Li, Meng Wang, Zhongqiu Zhao, Xiaoyue Li, Yun Han, Shibao Chen. Alleviation of cadmium phytotoxicity to wheat is associated with Cd re-distribution in soil aggregates as affected by amendments. RSC Advances. 2018; 8 (31):17426-17434.
Chicago/Turabian StyleShanshan Li; Meng Wang; Zhongqiu Zhao; Xiaoyue Li; Yun Han; Shibao Chen. 2018. "Alleviation of cadmium phytotoxicity to wheat is associated with Cd re-distribution in soil aggregates as affected by amendments." RSC Advances 8, no. 31: 17426-17434.