BIOSENSORS & BIOELECTRONICS
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2011
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IF 5.361
Xiaochun Jiang,Kun Chen,Heyou Han
A novel electrochemical biosensor was developed for detecting short DNA oligonucleotide of Bacillus thuringiensis (Bt) transgenic sequence based on Ag nanoparticle aggregates. To fabricate this DNA biosensor, the thiol-modified capture DNA (cDNA) was first anchored on gold (Au) electrode, and then the target DNA (tDNA) was hybridized with the immobilized cDNA. Subsequently, the probe DNA (pDNA) functionalized by biotinylated Ag nanoparticle was associated with the fixed tDNA, and the single Ag nanoparticle label was obtained (cited as SAg label). Finally, dissociative biotinylated Ag nanoparticle was bound to the resultant biotinylated SAg label assembled on Au electrode by virtue of bridge molecule streptavidin (SA) through biotin–SA specific interaction, which could lead to in situ aggregate of Ag nanoparticles on Au electrode and induce a novel tag including multiple Ag nanoparticles (cited as MAg tag). The novel tag exhibited excellent electroactive property in the solid-state Ag/AgCl process and was successfully applied to Bt transgenic sequence assay. A detection limit of 10 fM was achieved, which was improved by three orders of magnitude as compared to the SAg label. Furthermore, this novel DNA biosensor demonstrated a good selectivity towards tDNA.
研究领域:
生物技术
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分子生物学
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纳米科学
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DOI
高影响因子
Plants-Basel
·
2025
·Vol. 14
·期 18
·2918
·
IF 4.1
Guannan Kong,Da Song,Chao Zhang,Xinyao Jia,Yingying Ren,Shuhe Wei,Huiping Dai
Cadmium contamination in soil threatens ecological safety and human health. Phytoremediation has gained attention due to its cost-effectiveness and environmental sustainability. Studies show that plant growth-promoting rhizobacteria can enhance the ability of hyperaccumulator plants to remove heavy metals. This research aimed to isolate and identify plant-growth-promoting rhizobacteria under Cd stress and assess their impact on the growth and Cd accumulation ofSolanum nigrumL. Six bacterial strains were isolated from the rhizosphere ofS. nigrum, all showing high Cd tolerance. Among them, LKT25 exhibited multiple growth-promoting traits, including indole-3-acetic acid production, nitrogen fixation, 1-aminocyclopropane-1-carboxylate deaminase, and siderophore synthesis. Under varying Cd concentrations (5, 25, and 50 mg/kg), theBacillus thuringiensisstrain LKT25 significantly improved Cd removal byS. nigrum. At 5 mg/kg Cd, the removal efficiency reached 45.13%. LKT25 also enhanced plant growth, photosynthesis, and antioxidant activity, contributing to improved Cd remediation. This study provides new microbial resources and technical support for using rhizobacteria in remediating heavy metal-contaminated soils.
研究领域:
环境微生物学
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植物生理学
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土壤修复
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重金属污染治理
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环境生态学
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DOI
PubMed
高影响因子
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
·
2023
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IF 4.7
Jinsheng Xu,Lin Zheng,Mingtao Tan,Hongfei Wu,Shanchun Yan,Dun Jiang
Heavy metal pollution is an abiotic factor that can affect the efficiency of pest control. In this study, two microbial pesticides , Bacillus thuringiensis and Mamestra brassicae nuclear polyhedrosis virus (MbNPV), were used to treat Hyphantria cunea larvae with Cd pre-exposure, and the humoral and cellular immunity of H. cunea larvae with Cd exposure were evaluated. The results showed that Cd exposure increased the susceptibility of H. cunea larvae to microbial pesticides B. thuringiensis and MbNPV, and the lethal effect of Cd exposure and microbial pesticides on H. cunea larvae was synergistic. Cd exposure significantly decreased the expression of pathogen recognition genes (GNBP1 and GNBP3), signal transduction genes (Relish, Myd88, Tube, and Imd), and antimicrobial peptide gene (Lebocin) in the humoral immunity of H. cunea larvae compared with the untreated larvae. Parameters of cellular immunity, including the number of hemocytes , phagocytic activity , melanization activity, encapsulation activity, and the expression of three phagocytic regulatory genes (HEM1, GALE1, GALE2), were also found to decrease significantly in Cd-treated larvae. TOPSIS analysis showed that humoral immunity, cellular immunity, and total immunity levels of H. cunea larvae with Cd exposure were weaker than those in untreated larvae. Correlation analysis showed that the mortality of two microbial pesticides investigated in H. cunea larvae was negatively correlated with the humoral and cellular immunity of larvae. Taken togther, Cd exposure results in immunotoxic effects on H. cunea larvae and the use of microbial pesticides are an effective strategy for pest control in heavy metal-polluted areas.
研究领域:
昆虫学
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环境科学
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毒理学
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害虫管理
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2024
·Vol. 25
·期 3
·1708
·
IF 4.9
Ling Chen,Yueying Wang,Lei Zhu,Yong Min,Yuxi Tian,Yan Gong,Xiaoyan Liu
Root knot nematodes cause serious damage to global agricultural production annually. Given that traditional chemical fumigant nematicides are harmful to non-target organisms and the environment, the development of biocontrol strategies has attracted significant attention in recent years. In this study, it was found that theBacillus thuringiensisBerliner strain NBIN-863 exhibits strong fumigant nematicidal activity and has a high attraction effect onMeloidogyne incognita(Kofoid and White) Chitwood. Four volatile organic compounds (VOCs) produced by NBIN-863 were identified using solid-phase microextraction and gas chromatography–mass spectrometry. The nematicidal activity of four VOCs, namely,N-methylformamide, propenamide, 3-(methylthio)propionic acid, and phenylmalonic acid, was detected. Among these compounds, 3-(methylthio)propionic acid exhibited the highest direct contact nematicidal activity againstM. incognita, with an LC50 value of 6.27 μg/mL at 24 h. In the fumigant bioassay, the mortality rate ofM. incognitatreated with 1 mg/mL of 3-(methylthio)propionic acid for 24 h increased to 69.93%. Furthermore, 3-(methylthio)propionic acid also exhibited an inhibitory effect on the egg-hatching ofM. incognita. Using chemotaxis assays, it was determined that 3-(methylthio)propionic acid was highly attractive toM. incognita. In pot experiments, the application of 3-(methylthio)propionic acid resulted in a reduction in gall numbers, decreasing the number of galls per gram of tomato root from 97.58 to 6.97. Additionally, the root length and plant height of the treated plants showed significant increases in comparison with the control group. The current study suggests that 3-(methylthio)propionic acid is a novel nematicidal virulence factor ofB. thuringiensis. Our research provides evidence for the potential use of NBIN-863 or its VOCs in biocontrol against root knot nematodes.
研究领域:
农业科学
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植物病理学
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微生物学
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害虫管理
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DOI
PubMed
高影响因子
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