High-throughput, low-cost, and event-specific polymerase chain reaction detection of herbicide tolerance in genetically modified soybean A2704-12

An easily-performed high-throughput method for plant genomic DNA extraction

Genomic DNA isolation is a crucial technique for researchers studying plant molecular biology. A current widely-used protocol for DNA extraction needs a pestle and mortal for each sample and consumes a large amount of liquid nitrogen in grinding the samples. Most high-throughput methods depend on expensive machines for tissue homogenization. Here we developed a CTAB-based DNA extraction method using 2.0 mL microcentrifuge tubes for sample processing. This protocol has the advantages that it is suitable for a variety of plants, easily-performed without special equipment, and high-throughput; it effectively avoids sample cross-contamination, and is inexpensive, rapid and safe.

Development of an event-specific hydrolysis probe quantitative real-time polymerase chain reaction assay for Embrapa 5.1 genetically modified common bean (Phaseolus vulgaris)

A genetically modified (GM) common bean event, namely Embrapa 5.1, resistant to the bean golden mosaic virus (BGMV), was approved for commercialization in Brazil. Brazilian regulation for genetically modified organism (GMO) labeling requires that any food containing more than 1% GMO be labeled. The event-specific polymerase chain reaction (PCR) method has been the primary trend for GMO identification and quantitation because of its high specificity based on the flanking sequence. This work reports the development of an event-specific assay, named FGM, for Embrapa 5.1 detection and quantitation by use of SYBR Green or hydrolysis probe. The FGM assay specificity was tested for Embrapa 2.3 event (a noncommercial GM common bean also resistant to BGMV), 46 non-GM common bean varieties, and other crop species including maize, GM maize, soybean, and GM soybean. The FGM assay showed high specificity to detect the Embrapa 5.1 event. Standard curves for the FGM assay presented a mean efficiency of 95% and a limit of detection (LOD) of 100 genome copies in the presence of background DNA. The primers and probe developed are suitable for the detection and quantitation of Embrapa 5.1.