Degradation and detection of transgenic Bacillus thuringiensis DNA and proteins in flour of three genetically modified rice events submitted to a set of thermal processes.
This study aimed to investigate the degradation of three transgenic Bacillus thuringiensis (Bt) genes (Cry1Ab, Cry1Ac, and Cry1Ab/Ac) and the corresponding encoded Bt proteins in KMD1, KF6, and TT51-1 rice powder, respectively, following autoclaving, cooking, baking, or microwaving. Exogenous Bt genes were more stable than the endogenous sucrose phosphate synthase (SPS) gene, and short DNA fragments were detected more frequently than long DNA fragments in both the Bt and SPS genes. Autoclaving, cooking (boiling in water, 30 min), and baking (200 °C, 30 min) induced the most severe Bt protein degradation effects, and Cry1Ab protein was more stable than Cry1Ac and Cry1Ab/Ac protein, which was further confirmed by baking samples at 180 °C for different periods of time. Microwaving induced mild degradation of the Bt and SPS genes, and Bt proteins, whereas baking (180 °C, 15 min), cooking and autoclaving led to further degradation, and baking (200 °C, 30 min) induced the most severe degradation. The findings of the study indicated that degradation of the Bt genes and proteins somewhat correlated with the treatment intensity. Polymerase chain reaction, enzyme-linked immunosorbent assay, and lateral flow tests were used to detect the corresponding transgenic components. Strategies for detecting transgenic ingredients in highly processed foods are discussed.
Institute of Agriculture Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Xiaofu
X
Wang
Institute of Agriculture Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Xiaoyun
X
Chen
Institute of Agriculture Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Junfeng
J
Xu
College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Chen
C
Dai
College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: wbshenh@njau.edu.cn.
Wenbiao
W
Shen
D001413:Bacillus thuringiensis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D002681:China; D003296:Cooking; D053837:DNA Cleavage / Q000528:radiation effects; D004269:DNA, Bacterial / Q000032:analysis* / Q000378:metabolism; D005240:Feasibility Studies; D005513:Food Inspection / Q000379:methods*; D030841:Food, Genetically Modified / Q000528:radiation effects; D006358:Hot Temperature; D008872:Microwaves; D009838:Oligodeoxyribonucleotides / Q000032:analysis / Q000378:metabolism; D012275:Oryza / Q000737:chemistry* / Q000235:genetics; D010446:Peptide Fragments / Q000032:analysis / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000737:chemistry* / Q000235:genetics; D011089:Polydeoxyribonucleotides / Q000032:analysis / Q000378:metabolism; D055550:Protein Stability; D059748:Proteolysis / Q000528:radiation effects; D012639:Seeds / Q000737:chemistry* / Q000235:genetics
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D009838:Oligodeoxyribonucleotides; D010446:Peptide Fragments; D011089:Polydeoxyribonucleotides
DNA degradation; GMO detection; Genetically modified; Insect-resistant rice; Protein degradation; Thermal processing