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Jin Z.P.,Nanjing Agricultural University | Jin Z.P.,Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects | Luo K.,Nanjing Agricultural University | Zhang S.,Nanjing Agricultural University | And 3 more authors.
Chemosphere | Year: 2012

Investigation on organic xenobiotics bioaccumulation/biodegradation in green algae is of great importance from environmental point of view because widespread distribution of these compounds in agricultural areas has become one of the major problems in aquatic ecosystem. Also, new technology needs to be developed for environmental detection and re-usage of the compounds as bioresources. Prometryne as a herbicide is widely used for killing annual grasses in China and other developing countries. However, overuse of the pesticide results in high risks to contamination to aquatic environments. In this study, we focused on analysis of bioaccumulation and degradation of prometryne in Chlamydomonas reinhardtii, a green alga, along with its adaptive response to prometryne toxicity. C. reinhardtii treated with prometryne at 2.5-12.5μgL -1 for 4d or 7.5μgL -1 for 1-6d accumulated a large quantity of prometryne, with more than 2mgkg -1 fresh weight in cells exposed to 10μgL -1 prometryne. Moreover, it showed a great ability to degrade simultaneously the cell-accumulated prometryne. Such uptake and catabolism of prometryne led to the rapid removal of prometryne from media. Physiological and molecular analysis revealed that toxicology was associated with accumulation of prometryne in the cells. The biological processes of degradation can be interpreted as an internal tolerance mechanism. These results suggest that the green alga is useful in bioremediation of prometryne-contaminated aquatic ecosystems. © 2012 Elsevier Ltd. Source

Jiang L.,Nanjing Agricultural University | Jiang L.,Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects | Ma L.,Nanjing Agricultural University | Sui Y.,Nanjing Agricultural University | And 5 more authors.
Journal of Hazardous Materials | Year: 2010

Soil amendment with manure compost may influence environmental behaviors and bioavailability of toxic organic chemicals (e.g. pesticide and polycyclic aromatic hydrocarbons). Dynamic parameters like adsorption, kinetics, mobility and degradation of pesticides have been intensively investigated. However, the current methods to evaluate the ultimate real bioavailability of pesticides to crops using physiochemical or biological approaches are limited. In this study, we developed a set of comprehensive and cost-effective parameters relevant to crop response to prometryne (s-triazine herbicide) to assess the accumulation and genotoxicity of the pesticide. Wheat plants exposed to 8mgkg-1 prometryne for 10 d showed stunt growth, reduced chlorophyll content and damaged membrane lipid. Concomitant treatment with 5% pig manure compost (PMC) alleviated the toxic effect on the plant. Prometryne in soils was readily accumulated by wheat. However, such an accumulation was significantly inhibited by PMC application. Because excessively accumulated prometryne triggered oxidative damage to plants, the biochemical responses of several antioxidant enzymes along with their molecular expressions were determined. In most cases, the activities and transcriptional expression of the enzymes were activated upon the exposure to prometryne but the process was prevented by PMC application. The set of biological parameters tested in this study were very sensitive and cost-effective, and therefore can be used to evaluate the degree of pesticide contamination to plants and other organisms. © 2010 Elsevier B.V. Source

Yang Y.,Nanjing Agricultural University | Yang Y.,Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects | Wu H.-J.,Nanjing Agricultural University | Wu H.-J.,Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects | And 7 more authors.
Applied Microbiology and Biotechnology | Year: 2015

According to the change of environment, soil-dwelling Bacillus species differentiate into distinct subpopulations, such as spores and competent cells. Rap-Phr systems have been found to be involved in this differentiation circuit by interacting with major regulatory proteins, such as Spo0A, ComA, and DegU. In this study, we report that the plasmid-born RapQ-PhrQ system found in Bacillus amyloliquefaciens B3 affects three regulatory pathways in the heterologous host Bacillus subtilis. Expression of rapQ in B. subtilis OKB105 strongly suppressed its sporulation efficiency, transformation efficiency, and surfactin production. Co-expression of phrQ or addition of synthesized PhrQ pentapeptide in vitro could compensate for the suppressive effects caused by rapQ. We also found that expression of rapQ decreased the transcriptional level of the sporulation-related gene spoIIE and surfactin synthesis-related gene srfA; meanwhile, the transcriptional levels of these genes could be rescued by co-expression of phrQ and in vitro addition of PhrQ pentapeptide. Electrophoretic mobility shift (EMSA) result also showed that RapQ could bind to ComA without interacting with ComA binding to DNA, and PhrQ pentapeptide antagonized RapQ activity in vitro. These results indicate that this new plasmid-born RapQ-PhrQ system controls sporulation, competent cell formation, and surfactin production in B. subtilis OKB105. © 2015, Springer-Verlag Berlin Heidelberg. Source

Wu L.,Nanjing Agricultural University | Wu L.,Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects | Wu H.,Nanjing Agricultural University | Wu H.,Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects | And 7 more authors.
Applied Microbiology and Biotechnology | Year: 2015

Bacillus amyloliquefaciens strains FZBREP and FZBSPA were derived from the wild-type FZB42 by replacement of the native bacilysin operon promoter with constitutive promoters PrepB and Pspac from plasmids pMK3 and pLOSS, respectively. These strains contained two antibiotic resistance genes, and markerless strains were constructed by deleting the chloramphenicol resistance cassette and promoter region bordered by two lox sites (lox71 and lox66) using Cre recombinase expressed from the temperature-sensitive vector pLOSS-cre. The vector-encoded spectinomycin resistance gene was removed by high temperature (50 °C) treatment. RT-PCR and qRT-PCR results indicated that PrepB and especially Pspac significantly increased expression of the bac operon, and FZBREP and FZBSPA strains produced up to 170.4 and 315.6 % more bacilysin than wild type, respectively. Bacilysin overproduction was accompanied by enhancement of the antagonistic activities against Staphylococcus aureus (an indicator of bacilysin) and Clavibacter michiganense subsp. sepedonicum (the causative agent of potato ring rot). Both the size and degree of ring rot-associated necrotic tubers were decreased compared with the wild-type strain, which confirmed the protective effects and biocontrol potential of these genetically engineered strains. © 2014, Springer-Verlag Berlin Heidelberg. Source

Hou Y.,Nanjing Agricultural University | Hou Y.,Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects | Hou Y.,Key Laboratory of Pesticide | Zheng Z.,Nanjing Agricultural University | And 11 more authors.
Pesticide Biochemistry and Physiology | Year: 2013

JS399-19 (2-cyano-3-amino-3-phenylancryic acetate), a novel cyanoacrylate fungicide, has powerful inhibition against Fusarium species, especially to Fusarium graminearum. Treated with JS399-19, mycelium of F. graminearum was distorted and swelled. The embranchment increased. In order to investigate the effect of JS399-19 on protein expression of F. graminearum, total protein of F. graminearum cultured in normal condition and that treated with 0.5μg/mL (EC90 value) JS399-19 were extracted respectively and proteomic analysis was performed using two-dimensional gel electrophoresis. The expression levels of 38 proteins varied quantitatively at least twofold. 33 proteins out of the 38 were successfully identified by MALDI-TOF-MS/MS and MASCOT. According to the classification of physiological functions from Conserved Domain Database analysis, 19, 5, 2, 3, 2 and 2 proteins were respectively associated with metabolism, regulation, motility, defense, signal transduction, and unknown function, which indicated that energy metabolism, the synthesis and transport of proteins and DNA of F. graminearum were inhibited by JS399-19 in different degrees. The expression levels of the genes were further confirmed by quantitative real-time PCR analyses. This study represents the first proteomic analysis of F. graminearum treated by JS399-19 and will provide some useful information to find the mode of action of the fungicide against F. graminearum. © 2013 Elsevier Inc. Source

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