ENVIRONMENTAL POLLUTION
·
2020
·
IF 6.793
Dongmei Qiao,Hongfei Lu,Xiaoxian Zhang
Adding exogenous low-molecular weight organic acids is an effective technique to improve phytoremediation of Cd-contaminated soil and has been well documented, but how acid application rate affects remediation efficiency and its underlying limiting factors remains elusive. We investigated this using pot experiments with rapeseed ( Brassica napus L.) as the model plant. Plastic pots packed with a sandy loam contaminated by Cd at 4.838 mg/kg were amended with acetic acid, oxalic acid , citric acid , malic acid and tartaric acid, respectively, at an application rate gradient varying from 0.0 to 12.0 mmol/kg. Plants in each pot were harvested after growing for five months, and we then measured the exchangeable, carbonate, Fe–Mn oxide, organic and residual Cd in the rhizosphere, as well as Cd in both roots and shoots. The results showed that all organic acids improved plant uptake of Cd and, compared with the control without acid addition, they could improve Cd uptake by more than 100%. The enhanced Cd extraction was due to the increase in exchangeable Cd in the rhizosphere. Plant Cd was weakly correlated to the amount of Cd lost from a unit volume of the rhizosphere due to root extraction ( R 2 = 0.06), but a good negative correlation was found between them after normalizing the lost Cd by root biomass ( R 2 = 0.36). Mass balance analysis revealed that the average Cd content in soil (rhizosphere and bulk soils combined) was much higher than the Cd content in the rhizosphere, and the improved Cd mobility after acid addition was thus due to the increased chelation. As diffusion of ligands in water is one order in magnitude smaller than diffusion of Cd ions, our results suggested that Cd migration from the bulk soil into the rhizosphere was a major factor limiting Cd phytoextraction by rapeseed after adding the exogenous organic acids.
研究领域:
环境科学
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植物学
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产品关联
DOI
PubMed
高影响因子
Science China-Life Sciences
·
2022
·Vol. 66
·期 5
·1119-1133
·
IF 10.372
Luo Feifei,Tang Guirong,Hong Song,Gong Tianyu,Xin Xiu-Fang,Wang Chengshu
The ascomycete insect pathogenic fungi such as Metarhizium species have been demonstrated with the abilities to form the rhizosphere or endophytic relationships with different plants for nutrient exchanges. In this study, after the evident infeasibility of bacterial disease development in the boxed sterile soils, we established a hydroponic system for the gnotobiotic growth of Arabidopsis thaliana with the wild-type and transgenic strain of Metarhizium robertsii . The transgenic fungus could produce a high amount of pipecolic acid (PIP), a pivotal plant-immune-stimulating metabolite. Fungal inoculation experiments showed that M. robertsii could form a non-selective rhizosphere relationship with Arabidopsis . Similar to the PIP uptake by plants after exogenous application, PIP level increased in Col-0 and could be detected in the PIP-non-producing Arabidopsis mutant ( ald1 ) after fungal inoculations, indicating that plants can absorb the PIP produced by fungi. The transgenic fungal strain had a better efficacy than the wild type to defend plants against the bacterial pathogen and aphid attacks. Contrary to ald1, fmo1 plants could not be boosted to resist bacterial infection after treatments. After fungal inoculations, the phytoalexins camalexin and aliphatic glucosinolate were selectively increased in Arabidopsis via both PIP-dependent and -independent ways. This study unveils the potential mechanism of the fungus-mediated beneficial promotion of plant immunity against biological stresses. The data also highlight the added values of M. robertsii to plants beyond the direct suppression of insect pest populations.
研究领域:
植物学
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微生物学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
PLANT AND SOIL
·
2021
·Vol. 465
·期 1
·385-402
·
IF 4.192
Wang Baoying,Xia Qing,Li Yunlong,Zhao Jun,Yang Shaozhou,Wei Fugang,Huang Xinqi,Zhang Jinbo,Cai Zucong
Background and aims Root rot is a catastrophic disease of perennial medicinal plants which could be caused by various soil-borne fungal pathogens. However, the understanding of the composition and diversity of root rot pathogenic fungi, their successions and potential drivers remains limited. Methods Sanqi ginseng ( Panax notoginseng ) was selected as a model plant and the rhizosphere soils of root rot-infected Sanqi ginseng at different growth years were collected. Phenolic acid content, pathogen abundance, and fungal microbiota were examined by using the high-performance liquid chromatography (HPLC), real-time PCR and Miseq sequencing. Results Pathogenic agents dominated in the rhizospheric fungal microbiota of rotten Sanqi ginseng and mainly comprised of Ilyonectria , Plectosphaerella , Clonostachys , Gibberella , Pestalotiopsis , Fusarium , and Chalara , with Ilyonectria and Fusarium being most abundant. The composition of pathogenic microbiota, but not α-diversity indices, changed considerably with Sanqi ginseng growth. The shifts of phenolic acid profile were an important driver in changes of rhizosphere pathogenic microbiota, and same phenolic acid exerted distinct functions on differential pathogenic taxa. Particularly, the contents of p -coumaric acid, ferulic acid, and benzoic acid were positively correlated with the abundance of genus Fusarium and negatively correlated with the abundance of genus Ilyonectria . Conclusions Root rot-infected Sanqi ginseng rhizosphere harbors dynamically pathogenic microbiota driven by the shift of phenolic acids. This study provides insights into the composition, variation, and driver of root rot pathogenic microbiota; these insights are important for the development of targeted measure for the prevention and control of root rot diseases.
研究领域:
微生物学
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植物病理学
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土壤学
✓ 已验证
DOI
高影响因子
ENVIRONMENT INTERNATIONAL
·
2024
·
IF 10.3
Xuemin Qi,Ziyan Niu,Shenghua Xiao,Michael Gatheru Waigi,Hui Lin,Kai Sun
Global-scale crop contamination with environmental estrogens has posed a huge risk to agri-food safety and human health. Laccase is regarded as an unexceptionable biocatalyst for regulating pollution and expediting humification, but the knowledge of estrogen bioremediation and C storage strengthened by laccase-driven rhizosphere humification (LDRH) remains largely unknown. Herein, a greenhouse microcosm was performed to explore the migration and fate of 17 β -estradiol (E2) in water-wheat ( Triticum aestivum L.) matrices by LDRH. Compared to the non-added laccase, the pseudo-first-order decay rate constants of E2 in the rhizosphere solution after 10 and 50 μM exposures by LDRH increased from 0.03 and 0.02 h −1 to 0.36 and 0.09 h −1 , respectively. Furthermore, LDRH conferred higher yield, polymerizability, O-containing groups, and functional-C signals in the humified precipitates, because it accelerated the formation of highly complex precipitates by radical-controlled continuous polymerization. In particular, not only did LDRH mitigate the phytotoxicity of E2, but it also diminished the metabolic load of E2 in wheat tissues. This was attributed to the rapid attenuation of E2 in the rhizosphere solution during LDRH, which limited E2 uptake and accumulation in each subcellular fraction of the wheat roots and shoots. Although several typical intermediate products such as estrone, estriol, and E2 oligomers were detected in roots, only small-molecule species were found in shoots, evidencing that the polymeric products of E2 were unable to be translocated acropetally due to the vast hydrophobicity and biounavailability. For the first time, our study highlights a novel, eco-friendly, and sustainable candidate for increasing the low-C treatment of organics in rhizosphere microenvironments and alleviating the potential risks of estrogenic contaminants in agroenvironments.
研究领域:
环境科学
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植物学
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土壤生物学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Sciences
·
2022
·
IF 6.796
Shengwei Yi,Feng Li,Chen Wu,Fei Ge,Chuang Feng,Ming Zhang,Yun Liu,Hainan Lu
This study investigated the transformations of heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) in rhizosphere soils and adaptive responses of rhizobacterial community under the real field conditions during four growth stages (e.g., greening, tillering, heading, and maturity) of early rice (Zhongjiazao 17) and late rice (Zhongyou 9918) in Jiangshe village (JSV) and Yangji village (YJV). Results showed that rhizosphere soils of YJV were mildly polluted by Cd and PAHs compared to that of JSV. The relative abundance of bioavailable Cd (bio-Cd) and bioavailable As (bio-As) in rhizosphere soil increased before the heading stage but decreased at the subsequent growth stage, but the content of ΣPAHs in rhizosphere soil decreased gradually during whole growth period. The dominant rhizobacteria genera at YJV (e.g., Bacillus, Massilia, Sphingomonas , and Geobacter ) increased at an abundance level from the tillering to heading stage. Rhizobacteria interacted with the above co-pollutant more intensely at the tillering and heading stage, where genes involved in HM-resistance and PAH-degradation appeared to have a significant enhancement. The contents of bio-Cd and bio-As in rhizosphere soil of early rice were higher than that of late rice at each growth stage, especially at the heading stage. Bio-Cd, ΣPAHs, and organic matter were key factors influencing the community structure of rhizobacteria. Results of this study provide valuable insights about the interactions between HM-PAH co-pollutant and rhizobacterial community under real field conditions and thus develop in-situ rhizosphere remediation techniques for contaminated paddy fields.
研究领域:
环境科学
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微生物学
✓ 已验证
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Dong Li,Chunran Zhou,Shuai Wang,Zhan Hu,Jia Xie,Canping Pan,Ranfeng Sun
Overusing imidacloprid (IMI) has been found to impede secondary metabolism and hinder plant growth. The impact of IMI stress on the interaction between metabolites, rhizosphere, and plant-microbe dispersion through various pathways in pepper plants has not been extensively studied. This study investigated the effects of IMI on plant signaling components, secondary metabolic pathways, and microbial communities in the rhizosphere and phyllosphere . Here, the distribution of IMI and its metabolites (6-chloronicotinic acid, IMI-desnitro, 5-hydroxy-IMI, IMI-urea, and IMI-olefin) was primarily observed in the pepper plant leaves. A rise in IMI concentration had a more significant inhibitive effect on the metabolism of pepper leaves than on pepper roots. The findings of non-target metabolomics indicated that IMI exposure primarily suppresses secondary metabolism in pepper plants, encompassing flavones, phenolic acids, and phytohormones. Notably, the IMI treatment disrupted the equilibrium between plants and microbes by decreasing the population of microorganisms such as Vicinamibacteria , Verrucomicrobiae , Gemmatimonadetes , and Gammaproteobacteria in the phyllosphere, as well as Vicinamibacteria , Gemmatimonadetes , Gammaproteobacteria , and Alphaproteobacteria in the rhizosphere of pepper plants. The study demonstrates that overexposure to IMI harms microbial composition and metabolite distribution in the rhizosphere soil and pepper seedlings, inhibiting plant growth.
研究领域:
植物学
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环境科学
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微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CURRENT BIOLOGY
·
2024
·
IF 8.1
Yun Chen,Xia Hua,Siyu Li,Jiamei Zhao,Huan Yu,Dongyao Wang,Jiqiang Yang,Lijun Liu
Rice paddy has been the main source of anthropogenic methane (CH 4 ) emissions, with significant variations among rice varieties. 2-Acetyl-1-pyrroline (2-AP) is the key component of the pleasant aroma in fragrant rice. Here, we show that fragrant rice is metabolically active in nitrogen assimilation and exhibits high levels of 2-AP and that CH 4 fluxes at the booting stage and cumulative emissions are 25.5% and 14.8% lower, respectively, in fragrant rice paddies compared with nonfragrant rice paddies. Three precursors involved in 2-AP synthesis—proline, glutamic acid, and ornithine—are identified as crucial nitrogen compounds that significantly promote CH 4 oxidation in the rhizosphere. Augmenting 2-AP synthesis, either through foliar spraying or by utilizing CRISPR-Cas9 technology to generate knockout lines of BETAINE ALDEHYDE DEHYDROGENASE 2 gene, effectively enhances CH 4 oxidation and reduces CH 4 fluxes. Our findings reveal that the 2-AP metabolic pathway coordinates the carbon/nitrogen cycle to improve nitrogen assimilation along with high 2-AP levels and mitigate CH 4 emissions in paddy ecosystems.
研究领域:
植物学
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环境科学
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遗传学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Lan Feng,Nuohan Xu,Qian Qu,Zhenyan Zhang,Mingjing Ke,Tao Lu,Haifeng Qian
Silver nanoparticles (AgNPs) are one of the most commonly used nanomaterials in industrial and agricultural production. Glyphosate is a broad-spectrum systemic herbicide, which mainly acts in the phloem of weeds that compete with crop growth and is widely used in agriculture. This study investigated the interactive effects of AgNPs and glyphosate on the physiological morphology, gene transcription, and rhizosphere microorganisms of wheat. Our results demonstrated that wheat growth, and the structure and diversity of rhizosphere microorganisms were slightly influenced by AgNPs and glyphosate single treatment at the test concentration. However, AgNPs and glyphosate (Gly) combined treatment (AgNPs + Gly) strongly inhibited wheat growth and influenced gene transcription. In total, 955, 601, and 1336 genes were determined to be differentially expressed in AgNPs, glyphosate, and combined treatment, respectively. According to KEGG analysis, the combined groups induced an antioxidant response by upregulating the transcription of phenylpropanoid biosynthesis-related genes. In addition, more energy was needed, and disrupted cell membrane was shown in the combined treatment, which displayed in the upregulation of sucrose, starch, and lipid synthesis. Moreover, the relative abundance of Bradyrhizobium , Devosia , Kribbella , Sphingopyxis (nitrogen-fixing bacteria), and Streptomyces (plant growth-promoting bacteria) in soil microbiota were decreased, implicated that nitrogen fixation and some beneficial substance secretions were inhibited by the combined treatment. This study emphasized that the synergetic effects of AgNPs and glyphosate exerted a negative impact on wheat growth.
研究领域:
植物学
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环境科学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2013
·
IF 3.137
Jing Wei,Xiaoyan Liu,Qian Wang,Chuanhua Wang,Xueping Chen,Hongbing Li
Phytoremediation for PAH hydrocarbons has been widely studied, but few focus on the influence of rhizodeposition on their bioaccessibility during the process. This literature revealed the effect of celery ( Apium graveolens ) rhizodeposition on pyrene fractionation and bioaccessibility in simulated pyrene and pyrene–lead contaminated microcosms. A sequential extraction methodology was used to quantify different morphological fractions of pyrene in the soil, and phospholipid fatty acid (PLFA) pattern to monitor shifts in microbial populations. Bioaccessible pyrene accounted for the largest proportion of the total removal. Biodegradation of both bioaccessible and associated pyrene fractions was enhanced by celery rhizodeposition in pyrene spiked soils. However, rhizodeposition promoted the removal of bioaccessible rather than associated fractions in pyrene–lead spiked soils. In contrast, the bound fraction increased over time in pyrene spiked soils without amendment, but kept relatively stable in amended microcosms. It was found that rhizodeposition facilitated the reproduction of all the subgroups of soil microorganisms through PLFA analysis. Although all the subgroups contributed to the removal of bioaccessible pyrene, only abundances of unsaturated and cyclic fatty acids were positively correlated with the removal of associated pyrene. These findings provide meaningful insights into the microecological mechanisms involved in the phytoremediation of PAH polluted sites.
研究领域:
环境科学
·
土壤生态学
·
植物修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Xinyao Shi,Wen Fang,Ni Tang,Paul N. Williams,Xuan Hu,Zhaodong Liu,Daixia Yin,Lena Q. Ma,Jun Luo
The speciation of selenium (Se) controls its fate and behavior, determining both its biological and environmental activities. However, in situ monitoring of SeIV presents a significant challenge due to its sensitivity to redox change. A novel diffusive gradients in thin films (DGT) technique containing mercapto-, amino-bifunctionalized SBA15 mesoporous silica nanoparticles was developed and evaluated in a series of laboratory and field deployment tests. The SBA-DGT exhibited a linear accumulation of SeIV (r2 > 0.997) over a 72 h deployment, with negligible accumulation of SeVI(<5%). Consistent prediction of SeIV occurred within ionic strength and pH ranges of 0.1–200 mmol L–1 and 3.6–8, respectively. Limits of detection of the SBA-DGT were 0.03 μg SeIV L–1, which is suitable for natural waters. Moreover, the properties of the bifunctionalized SBA15 enable it to be fabricated within ultrathin (0.05 mm) gel layers for use in conjunction with O2 planar optode imaging. This new sandwich sensor technology with SBA-DGT was validated by mapping the two-dimensional distribution of SeIV and oxygen simultaneously in rice rhizospheres. This study shows that SBA-DGT provides a selective measurement of SeIV in situ, demonstrating its potential for both environmental monitoring and as a research tool for improving our understanding of Se biogeochemical processes.
研究领域:
环境科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Yanhui Dai,Feiran Chen,Le Yue,Teng Li,Zhixiang Jiang,Zefeng Xu,Zhenyu Wang,Baoshan Xing
Many studies demonstrated that CeO2 nanoparticles (NPs) could protect plant from stress and improve plant growth, with a great application potential in agriculture. However, our knowledge of their fate particularly in asexual plants and their effect on the rhizosphere microbiome is limited. In this study, the transport and transformation of CeO2 NPs in an asexual plant—strawberry (Fragaria × ananassa Duch.)—were investigated. The effects of root-exuded/newly formed Ce species on rhizosphere bacterial community were also examined. Strawberries were exposed to CeO2 NPs at 0–2000 mg/L for 45 days via a split-root system in the field. CeO2 NPs were taken up by the exposed mother ramet roots and then translocated to all the mother and daughter ramet tissues. As indicated by the analysis from high-resolution transmission electron microscopy and X-ray absorption near-edge structures, in addition to CeO2 NPs, CePO4, Ce(III) acetate, and Ce(III)-cysteine were found in the roots, and CePO4 was present in the rhizosphere soil. The Ce species in the rhizosphere soil decreased the rhizosphere microbial diversity, but stimulated the relative abundance of specific plant growth promoting rhizobacteria. These results provide new insights for understanding the benefits and sustainable applications of NPs.
研究领域:
农业
·
环境科学
·
微生物学
·
植物科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Chenxi Zhang,Haibo Li,Yue Yang,Xulun Zhou,Damiao Zhuang,Wengang Liu,Kaixuan Wang,Pengkai Wang,Wenxin Zhang,Yaran Bai,Haotian Ma,Bingqian Gao,Rui Wang
Rhizosphere phosphatases can exhibit hormetic effects in response to cadmium (Cd) ion stimulation. However, understanding the mechanisms underlying hormesis effects on soil ecosystems is challenging as studies on hormesis are usually specific to an organism, cell, or organ. To comprehensively investigate the mechanism of phosphatase hormesis, this study utilized in situ zymography and metabolomics to analyze the rhizosphere of Trifolium repens L. (white clover). Zymograms showed that rhizosphere phosphatase displayed a hormetic effect in 10 mg kg −1 Cd contaminated soil, with a hotspot area 1.8 times larger than non-Cd contaminated soil and a slight increase in enzyme activity . Nevertheless, the phosphatase activity was substantially suppressed upon elevating the Cd concentration in the soil to 50 mg kg −1 . Differential metabolite identification and KEEG pathway enrichment analysis revealed that both rhizosphere organic acids and amino acid compounds positively affected phosphatase activity, and both were able to stabilize complexation with Cd ions via carboxyl groups . Besides, molecular docking models suggested that Cd ions act as cofactors to induce the formation of hydrogen bonds between amino acids/organic acids and phosphatase residues to form a triplet complex with a more stable structure, thereby improving phosphatase activity. The results indicated that amino acids and organic acids are heavily enriched in the rhizosphere of white clover and form a particular structure with soil Cd ions and phosphatase, which is essential for inducing the phosphatase hormesis as a detoxification mechanism in the rhizosphere micro-ecosystem.
研究领域:
环境科学
·
植物生理学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）