Plant breeding involving genetic engineering does not result in unacceptable unintended effects in rice relative to conventional cross-breeding
Advancements in -omics techniques provide powerful tools to assess potential effects in composition of a plant at the RNA, protein and metabolite levels. These technologies can thus be deployed to assess whether genetic engineering causes changes in plants that go beyond the changes introduced by conventionally plant breeding. Here, we compare the extent of transcriptome and metabolome modification occurring in leaves of four GE rice lines expressing Bacillus thuringiensis (Bt) genes that developed by genetic engineering and seven rice lines developed by conventional cross-breeding. The results showed that both types of crop breeding methods can bring changes at transcriptomic and metabolic levels, but the differences were comparable between the two methods, and were less than those between conventional non-GE lines. Metabolome profiling analysis found several new metabolites in GE rice lines when compared to the closest non-GE parental lines, but these compounds were also found in several of the conventionally bred rice lines. Functional analyses suggest that the differentially expressed genes and metabolites caused by both genetic engineering and conventional cross-breeding do not involve detrimental metabolic pathways. The study successfully employed RNA-sequencing and HPLC-MS technology to assess the unintended changes in new rice varieties, and the results suggest that genetic engineering does not cause unintended effects that go beyond conventional cross-breeding in rice. Overall design: We compare the extent of transcriptome and metabolome modification occurring in leaves of four GE rice lines expressing Bacillus thuringiensis (Bt) genes that developed by genetic engineering and seven rice lines developed by conventional cross-breeding.