The accumulation and persistence of Bt toxins in soils from Bt plants and Bt biopesticides may result in environmental hazards such as adverse impacts on soil microorganisms. However, the dynamic relationships among exogenous Bt toxins, soil characteristics, and soil microorganisms are not well understood. Cry1Ab is one of the most commonly used Bt toxins and was added to soils in this study to evaluate subsequent changes in soil physiochemical properties, microbial taxa, microbial functional genes, and metabolites profiles via 16S rRNA gene pyrosequencing, high-throughput qPCR, metagenomic shotgun sequencing, and untargeted metabolomics.
View Article and Find Full Text PDFThe environmental impacts of genetically modified (GM) plants remain a controversial global issue. To address these issues, comprehensive environmental risk assessments of GM plants is critical for the sustainable development and application of transgenic technology. In this paper, significant differences were not observed between microbial metagenomic and metabolomic profiles in surface waters of the Bt rice (T1C-1, the transgenic line) and non-Bt cultivars (Minghui 63 (the isogenic line) and Zhonghua 11 (the conventional japonica cultivar)).
View Article and Find Full Text PDFRapid, accurate and visual point-of-care testing (POCT) methods for pathogenic bacteria detection are essential for avoiding foodborne diseases caused by pathogens or their toxins. In this study, we proposed a rapid and visual detection method that we named "Cas12aVIP". By combining recombinase polymerase amplification (RPA), a CRISPR/Cas12a system and a cationic-conjugated polythiophene derivative (poly[3-(3'-N,N,N-triethylamino-1'-propyloxy)-4-methyl-2,5-thiophene hydrochloride] (PMNT) mixed with single-stranded DNA (ssDNA)), the solution turned red in the absence of the target DNA based on conformational modifications of the conjugated backbone of PMNT, whereas it displayed yellow, thus realizing the colorimetric detection of DNA.
View Article and Find Full Text PDFIn order to seek high profit, businesses mix beef and mutton with cheap meat, such as duck, pork, and chicken. Five pairs of primers were designed for quintuple droplet digital PCR (qddPCR) of specific genomic regions from five selected species and specificity and amplification efficiency were determined. The mixed DNA template with an equal copy number was used for detecting the accuracy and limit of multiplex PCR.
View Article and Find Full Text PDFproteins are crystal proteins produced by () in the early stage of spore formation that exhibit highly specific insecticidal activities. The application of proteins primarily includes transgenic plants and biopesticides. Transgenic crops with insect resistance (via )/herbicide tolerance comprise the largest global area of agricultural planting.
View Article and Find Full Text PDFSustainable intensive cropping systems have been implemented for three decades in suburban agricultural districts of Shanghai, China. These human-managed soils have been developed from paleosol or alluvial soils across different regions. However, little is known about the geographical distribution patterns of microbes and microbial community assembly in the sustainable intensive soils after decades of anthropogenic disturbances.
View Article and Find Full Text PDFSynthetic Cry1Ab/Ac proteins expressed by genetically modified (GM) crops have a high potential to control insect pests without utilizing large amounts of chemical insecticides. Before these crops are used in agriculture, the environmental fate and interactions in the soil must be understood. Stable isotope-labeled Cry1Ab/Ac protein is a highly useful tool for collecting such data.
View Article and Find Full Text PDFBackground: Bacillus thuringiensis (Bt) crops have been cultivated at a large scale over the past several decades, which have raised concern about unintended effects on natural environments. Microbial communities typically contain numerous rare taxa that make up the majority of community populations. However, the response of dominant and rare taxa for fungal diversity to the different root environments of Bt plants remains unclear.
View Article and Find Full Text PDFThe impacts of rice varieties with stacked drought tolerance and insect resistance on soil microbiomes are poorly understood. Hence, the objective of this study was to investigate the effects resulting from the cultivation of the drought-tolerant and insect-resistant rice cultivar, Hanhui3T, on soil physical-chemical properties, and bacterial and fungal community composition. Soil samples of Hanhui3T and conventional rice varieties (Hanhui3 and Zhonghua11) were collected in triplicate at the booting stage, and bacterial and fungal population sizes and community structures were assessed using qPCR and Illumina MiSeq sequencing, respectively.
View Article and Find Full Text PDFThe objective of this study was to characterize the diversity and dynamics of rhizosphere bacterial community, especially the response of dominant and rare bacterial taxa to the cultivation of Bt cotton for different root environments at different growth stages. qPCR analyses indicated that bacterial abundances of the taproots and lateral root rhizospheres of the Bt cotton SGK321 were significantly different at seedling and bolling stages. But no significant differences were detected between the same root zones from Bt and the conventional cotton varieties.
View Article and Find Full Text PDFFood allergies cause health risks to susceptible consumers and regulations on labeling of food allergen contents have been implemented in many countries and regions. To achieve timely and accurate food allergen labeling, the development of fast and effective allergen detection methods is very important. Herein, a decaplex polymerase chain reaction (PCR) assay combined with capillary electrophoresis was developed to detect simultaneously 10 common food allergens from hazelnut, pistachio, oat, sesame, peanut, cashew, barley, wheat, soybean and pecan.
View Article and Find Full Text PDFFor transferring the event-specific PCR methods of genetically modified papaya Huanong No.1 to other laboratories, we validated the previous developed PCR assays of Huanong No.1 according to the international standard organization (ISO) guidelines.
View Article and Find Full Text PDFGenetically modified carnation (Dianthus caryophyllus L.) Moonshade was approved for planting and commercialization in several countries from 2004. Developing methods for analyzing Moonshade is necessary for implementing genetically modified organism labeling regulations.
View Article and Find Full Text PDFThe validation of the anthocyanin synthase (ANS) gene as a carnation endogenous reference gene applicable both in classical and real-time PCR methods is a prerequisite for the development of PCR assays for genetically modified (GM) carnation detection. This is important due to the fact that GM carnation lines, developed by Florigene Pty Ltd, have been approved for commercialization. In this study, both methods were tested on 14 different carnation cultivars, and identical amplification products were obtained with all of them.
View Article and Find Full Text PDFWintersweet (Chimonanthus praecox), a basal angiosperm endemic to China, has high ornamental value for developing beautiful flowers with strong fragrance. The molecular mechanism regulating flower development in wintersweet remains largely elusive. In this project, we seek to determine the molecular features and expression patterns of the C.
View Article and Find Full Text PDFRetrotransposons, the important component of eukaryotic genome, are seeds of evolution and play great role in creating new genes. The compact Arabidopsis genome harbors over 200 Copia-like retrotransposons, but mostly silent. Here we isolated an expressed gene AtCopeg1 (Copia evolved gene 1), which shows higher than 90% identity to AtCopia95_I, the consensus sequence encoding AtCopia95 polyprotein.
View Article and Find Full Text PDFWith the development of genetically modified organism (GMO) detection techniques, the Polymerase Chain Reaction (PCR) technique has been the mainstay for GMO detection, and real-time PCR is the most effective and important method for GMO quantification. An event-specific detection strategy based on the unique and specific integration junction sequences between the host plant genome DNA and the integrated gene is being developed for its high specificity. This study establishes the event-specific detection methods for TC1507 and CBH351 maizes.
View Article and Find Full Text PDFPolymerase chain reaction (PCR) methods have been the main technical support for the detection of genetically modified organisms (GMOs). To date, GMO-specific PCR detection strategies have been developed basically at four different levels, such as screening-, gene-, construct-, and event-specific detection methods. Event-specific PCR detection method is the primary trend in GMO detection because of its high specificity based on the flanking sequence of exogenous integrant.
View Article and Find Full Text PDFFaeG is the key factor in the infection process of K88ad enterotoxigenic Escherichia coli(ETEC) fimbrial adhesin. In an attempt to determine the possibility of expressing recombinant FaeG with immunogenicity for a new safe and high-production vaccine in E. coli, we constructed the recombinant strain, BL21 (DE3+K88), which harbors an expression vector with a DNA fragment of faeG, without a signal peptide.
View Article and Find Full Text PDFThe importance of adhesins in pathogenicity has resulted in them being useful targets in the defense against bacterial infections. To produce edible vaccines against piglet diarrhea caused by enterotoxigenic Escherichia coli (ETEC), plants were genetically engineered to produce recombinant fimbrial adhesin FaeG. To evaluate the efficacy of the edible vaccine FaeG in mice, the soluble protein extracts were examined by about 15 microg recombinant FaeG for each oral immunization dose per mouse.
View Article and Find Full Text PDFA novel plant-based vaccine protecting against foot-and-mouth disease (FMD) was developed by inserting the VP21 epitope into the internal region of the hepatitis B virus core antigen gene (HBcAg). The specific sequence of the VP21 epitope is located within the VP1 capsid protein of the FMD virus (FMDV). It spans 21 amino acids located between positions 140 and 160 of the G-H loop.
View Article and Find Full Text PDFBased on the DNA sequences of the junctions between recombinant and cotton genomic DNA of the two genetically modified (GM) cotton varieties, herbicide-tolerance Mon1445 and insect-resistant Mon531, event-specific primers and probes for qualitative and quantitative PCR detection for both GM cotton varieties were designed, and corresponding detection methods were developed. In qualitative PCR detection, the simplex and multiplex PCR detection systems were established and employed to identify Mon1445 and Mon531 from other GM cottons and crops. The limits of detection (LODs) of the simplex PCR were 0.
View Article and Find Full Text PDFBecause of the genetically modified organisms (GMOs) labeling policies issued in many countries and areas, polymerase chain reaction (PCR) methods were developed for the execution of GMO labeling policies, such as screening, gene specific, construct specific, and event specific PCR detection methods, which have become a mainstay of GMOs detection. The event specific PCR detection method is the primary trend in GMOs detection because of its high specificity based on the flanking sequence of the exogenous integrant. This genetically modified maize, MON863, contains a Cry3Bb1 coding sequence that produces a protein with enhanced insecticidal activity against the coleopteran pest, corn rootworm.
View Article and Find Full Text PDFAs the genetically modified organisms (GMOs) labeling policies are issued in many countries, qualitative and quantitative polymerase chain reaction (PCR) techniques are increasingly used for the detection of genetically modified (GM) crops in foods. Qualitative PCR and TaqMan real-time quantitative PCR methods to detect and identify three varieties of insect resistant cotton, i.e.
View Article and Find Full Text PDFWith the development of transgenic crops, regulations to label the genetically modified organisms (GMOs) and their derived products have been issued in many countries. Polymerase chain reaction (PCR) methods are thought to be reliable and useful techniques for qualitative and quantitative detection of GMOs. These methods are generally needed to amplify the transgene and compare the amplified results with that of a corresponding reference gene to get the reliable results.
View Article and Find Full Text PDF