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 30 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 eventspecific
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.