scholarly journals The application of the ‘Gene-deletor’ technology in banana

2019 ◽  
Vol 140 (1) ◽  
pp. 105-114
Author(s):  
Chun-hua Hu ◽  
Qiao-song Yang ◽  
Xiu-hong Shao ◽  
Tao Dong ◽  
Fang-cheng Bi ◽  
...  
Keyword(s):  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Flower Initiation ◽  
Banana Fruit ◽  
Gus Staining ◽  
Candidate Promoter ◽  
Banana Industry ◽  
Polymerase Chain ◽  
Powerful Strategy ◽  
Exogenous Gene

Abstract Banana (Musa spp.) is an important tropical crop. Banana industry is under biotic and abiotic stresses such as Fusarium wilt, typhoon, cold stress. Genetic engineering offers a powerful strategy to create germplasm of banana with enhanced resistance. The safety of genetically modified organisms has become a bottleneck restricting the popularization and application of genetically modified technology. In this study, a candidate promoter, LEAFY (LFY) for expression and flower initiation in Arabidopsis, was cloned and constructed to ‘Gene-deletor’ vector. Histochemical β-glucuronidase (GUS) staining results showed that the ‘Gene-deletor’ vector driven by LFY promoter could lead to 88.5% excision efficiency from Arabidopsis seeds based on more than 200 T3 progeny examined per event. GUS staining was found to be partially negative in transgenic bananas, however, polymerase chain reaction could still detect the presence of large fragments of the vector. These results suggest that although LFY promoter could not completely drive the ‘Gene-deletor’ vector to achieve the effect of complete elimination of exogenous gene in bananas, its efficiency of eliminating exogenous gene laid a theoretical foundation for cloning banana fruit-specific promoters, that is, ‘non-transgenic’ GM bananas.

scholarly journals Quantitation of 35S Promoter in Maize DNA Extracts from Genetically Modified Organisms Using Real-Time Polymerase Chain Reaction, Part 2: Interlaboratory Study

2005 ◽  
Vol 88 (2) ◽  
pp. 558-573 ◽  
Author(s):  
Max Feinberg ◽  
Sophie Fernandez ◽  
Sylvanie Cassard ◽  
Chrystèle Charles-Delobel ◽  
Yves Bertheau ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Interlaboratory Study ◽  
Performance Criteria ◽  
Tolerance Interval ◽  
Chain Reaction ◽  
Qrt Pcr ◽  
Polymerase Chain

Abstract The European Committee for Standardization (CEN) and the European Network of GMO Working Laboratories have proposed development of a modular strategy for stepwise validation of complex analytical techniques. When applied to the quantitation of genetically modified organisms (GMOs) in food products, the instrumental quantitation step of the technique is separately validated from the DNA extraction step to better control the sources of uncertainty and facilitate the validation of GMO-specific polymerase chain reaction (PCR) tests. This paper presents the results of an interlaboratory study on the quantitation step of the method standardized by CEN for the detection of a regulatory element commonly inserted in GMO maize-based foods. This is focused on the quantitation of P35S promoter through using the quantitative real-time PCR (QRT-PCR). Fifteen French laboratories participated in the interlaboratory study of the P35S quantitation operating procedure on DNA extract samples using either the thermal cycler ABI Prism® 7700 (Applied Biosystems, Foster City, CA) or Light Cycler® (Roche Diagnostics, Indianapolis, IN). Attention was focused on DNA extract samples used to calibrate the method and unknown extract samples. Data were processed according to the recommendations of ISO 5725 standard. Performance criteria, obtained using the robust algorithm, were compared to the classic data processing after rejection of outliers by the Cochran and Grubbs tests. Two laboratories were detected as outliers by the Grubbs test. The robust precision criteria gave values between the classical values estimated before and after rejection of the outliers. Using the robust method, the relative expanded uncertainty by the quantitation method is about 20% for a 1% Bt176 content, whereas it can reach 40% for a 0.1% Bt176. The performances of the quantitation assay are relevant to the application of the European regulation, which has an accepted tolerance interval of about ±50%. These data were fitted to a power model (r2 = 0.96). Thanks to this model, it is possible to propose an estimation of uncertainty of the QRT-PCR quantitation step and an uncertainty budget depending on the analytical conditions.

scholarly journals Detection of Genetic Modification in Cured Tobacco Leaf: Proficiency Testing Using Polymerase Chain Reaction-Based Methods

2006 ◽  
Vol 89 (3) ◽  
pp. 693-707
Author(s):  
Ferruccio Gadani ◽  
Martin Ward ◽  
Sue Black ◽  
Neil Harris ◽  
David McDowell ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Proficiency Testing ◽  
Quantitative Methods ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Cauliflower Mosaic Virus ◽  
Chain Reaction ◽  
Tobacco Leaf ◽  
Qualitative And Quantitative ◽  
Polymerase Chain

Abstract The Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA; Paris, France) Task Force Genetically Modified TobaccoDetection Methods investigated the performance of qualitative and quantitative methods based on the polymerase chain reaction (PCR) for the detection and quantitation of genetically modified (GM) tobacco. In the 4 successful rounds of proficiency testing, the cauliflower mosaic virus 35S RNA promoter (CaMV 35S) and the Agrobacterium tumefaciens nopaline synthase terminator (NOS) were selected as target sequences. Blind-coded reference materials containing from 0.1 to 5.0% and from 0.15 to 4% GM tobacco were used in 2 rounds of qualitative and quantitative PCR, respectively. Eighteen laboratories from 10 countries participated in this study. Considering all methods and 2 rounds, the different laboratories were able to detect GM tobacco at the 0.1% level in 46 out of 58 tests in qualitative assays. The results of the proficiency test indicate that both end point screening and real-time quantitative methods are suitable for the detection of genetically modified organisms in tobacco leaf samples having a GM content of 0.1% or higher. The CORESTA proficiency study represents a first step towards the interlaboratory evaluation of accuracy and precision of PCR-based GM tobacco detection, which may lead to the harmonization of analytical procedures and to the enhancement of comparability of testing results produced by different laboratories.

scholarly journals Real-Time Polymerase Chain Reaction Detection of Cauliflower mosaic virus to Complement the 35S Screening Assay for Genetically Modified Organisms

2005 ◽  
Vol 88 (3) ◽  
pp. 814-822 ◽  
Author(s):  
Katarina Cankar ◽  
Maja Ravnikar ◽  
Jana Žel ◽  
Kristina Gruden ◽  
Nataša Toplak
Keyword(s):  
Polymerase Chain Reaction ◽  
Mosaic Virus ◽  
Real Time ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Pcr Amplification ◽  
Cauliflower Mosaic Virus ◽  
Chain Reaction ◽  
Screening Assay ◽  
Polymerase Chain

Abstract Labeling of genetically modified organisms (GMOs) is now in place in many countries, including the European Union, in order to guarantee the consumer's choice between GM and non-GM products. Screening of samples is performed by polymerase chain reaction (PCR) amplification of regulatory sequences frequently introduced into genetically modified plants. Primers for the 35S promoter from Cauliflower mosaic virus (CaMV) are those most frequently used. In virus-infected plants or in samples contaminated with plant material carrying the virus, false-positive results can consequently occur. A system for real-time PCR using a TaqMan minor groove binder probe was designed that allows recognition of virus coat protein in the sample, thus allowing differentiation between transgenic and virus-infected samples. We measured the efficiency of PCR amplification, limits of detection and quantification, range of linearity, and repeatability of the assay in order to assess the applicability of the assay for routine analysis. The specificity of the detection system was tested on various virus isolates and plant species. All 8 CaMV isolates were successfully amplified using the designed system. No cross-reactivity was detected with DNA from 3 isolates of the closely related Carnation etched ring virus. Primers do not amplify plant DNA from available genetically modified maize and soybean lines or from different species of Brassicaceae or Solanaceae that are natural hosts for CaMV. We evaluated the assay for different food matrixes by spiking CaMV DNA into DNA from food samples and have successfully amplified CaMV from all samples. The assay was tested on rapeseed samples from routine GMO testing that were positive in the 35S screening assay, and the presence of the virus was confirmed.

scholarly journals Characterization of Genetically Modified Maize in Weakly Contaminated Seed Batches and Identification of the Origin of the Adventitious Contamination

2007 ◽  
Vol 90 (4) ◽  
pp. 1098-1106 ◽  
Author(s):  
Laetitia Petit ◽  
Galle Pagny ◽  
Fabienne Baraige ◽  
Anne-Ccile Nignol ◽  
David Zhang ◽  
...  
Keyword(s):  
Ssr Markers ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
The European Union ◽  
Maize Seeds ◽  
Genetic Modifications ◽  
Polymerase Chain ◽  
The Individual ◽  
The Eu

Abstract So far, relatively few genetically modified plants (GMPs) have been planted in the European Union (EU). However, in France, seed batches weakly contaminated by unidentified GM materials have recently been detected among commercial maize seeds (14 seed batches positive out of 447 analyzed). We have developed a 3-step approach to precisely identify the genetic modifications detected in such maize seed batches. First, to isolate GMPs derived from the contaminated seed batches, 10 000 maize seeds of each batch were planted and screened by polymerase chain reaction (PCR) on 100-plant batches, then on 10-plant subbatches, and finally, plant by plant. In a second step, specific identification of the individual GMPs was performed. Finally, to determine the origin of the contamination, each individual GMP was analyzed by simple sequence repeat (SSR) markers. The results showed that all batches were contaminated by few GM seeds, having a GM content <0.1%. Finally, 12 individual GMPs have been isolated from 17 plant pools that were tested positive either for P35-S and/or T-Nos. MON810 and T25 transformation events approved for cultivation in the EU were detected in 7 individual GMPs. The other seed batches were contaminated by genetically modified organisms (GMOs) that are not approved in the EU, including GA21 or the stacking MON810/T25. Presumable identification of T14 was also achieved following sequencing of 1 individual GMP. The data also showed that most of the seed batches were contaminated by several transformation events. Finally, analysis of SSR markers indicated that the contaminations were essentially due to cross-pollination in the seed production process.

scholarly journals Applicability of Three Alternative Instruments for Food Authenticity Analysis:GMO Identification

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
A. Burrell ◽  
C. Foy ◽  
M. Burns
Keyword(s):  
Polymerase Chain Reaction ◽  
Gel Electrophoresis ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Fitness For Purpose ◽  
Chain Reaction ◽  
Food Authenticity ◽  
Pcr Products ◽  
Polymerase Chain

Ensuring foods are correctly labelled for ingredients derived from genetically modified organisms (GMOs) is an issue facing manufacturers, retailers, and enforcement agencies. DNA approaches for the determination of food authenticitys often use the polymerase chain reaction (PCR), and PCR products can be detected using capillary or gel electrophoresis. This study examines the fitness for purpose of the application of three laboratory electrophoresis instruments (Agilent Bioanalyzer 2100, Lab901 TapeStation, and Shimadzu MCE-202 MultiNA) for the detection of GMOs using PCR based on a previously validated protocol. Whilst minor differences in the performance characteristics of bias and precision were observed, all three instruments demonstrated their applicability in using this protocol for screening of GMO ingredients.

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