title: Evaluation of real-time PCR detection methods for detecting rice products contaminated by rice genetically modified with a CpTI-KDEL-T-nos transgenic construct.
abstract: Genetically modified (GM) rice (Oryza sativa) lines, such as insecticidal Kefeng and Kemingdao, have been developed and found unauthorised in processed rice products in many countries. Therefore, qualitative detection methods for the GM rice are required for the GM food regulation. A transgenic construct for expressing cowpea (Vigna unguiculata) trypsin inhibitor (CpTI) was detected in some imported processed rice products contaminated with Kemingdao. The 3' terminal sequence of the identified transgenic construct for expression of CpTI included an endoplasmic reticulum retention signal coding sequence (KDEL) and nopaline synthase terminator (T-nos). The sequence was identical to that in a report on Kefeng. A novel construct-specific real-time polymerase chain reaction (PCR) detection method for detecting the junction region sequence between the CpTI-KDEL and T-nos was developed. The imported processed rice products were evaluated for the contamination of the GM rice using the developed construct-specific real-time PCR methods, and detection frequency was compared with five event-specific detection methods. The construct-specific detection methods detected the GM rice at higher frequency than the event-specific detection methods. Therefore, we propose that the construct-specific detection method is a beneficial tool for screening the contamination of GM rice lines, such as Kefeng, in processed rice products for the GM food regulation.
authors.affiliation: National Institute of Health Sciences, 1-18-1 Kamiyoga, Tokyo 158-8501, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Nakamura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Akiyama
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kawano
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Kayo
authors.initials: K
authors.lastname: Yoshimatsu
authors.forename: Junichi
authors.initials: J
authors.lastname: Mano
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kitta
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Ohmori
authors.forename: Akio
authors.initials: A
authors.lastname: Noguchi
authors.forename: Kazunari
authors.initials: K
authors.lastname: Kondo
authors.forename: Reiko
authors.initials: R
authors.lastname: Teshima
mesh_terms: D005506:Food Contamination / Q000032:analysis*; D030841:Food, Genetically Modified; D012275:Oryza / Q000737:chemistry / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*
keywords: Bacillus thuringiensis toxin; Detection method; Genetically modified rice; Particle bombardment; Trypsin inhibitor