Qualitative observation on persistence and microbial transformation of recombinant DNA from transgenic rice biomass incubated in in vitro rumen system

The persistence time and transformation possibility to the rumen bacteria genome of the foreign genes (Bar and CaMV 35S) and self genes (SPS and Actin) in grain and straw of a glufosinate herbicide-tolerant transgenic rice (Bar68-1) and its transgenic hybrid generation (X125s/Bar68-1) were investigated in an in vitro fermentation system with the rumen fluid/buffer. Results showed that the fermentation characteristics of rice grain and straw were similar between Bar68-1 and X125s/Bar68-1. The Bar and CaMV 35S genes in the rice grain and straw could persist for 36 and 62 h, respectively in the incubation media, which were similar to the persistence times for the self genes. No dissociative gene fragment was detected in the supernatant of the rumen fluid/buffer media. No fragment of the Bar and CaMV 35S genes was detectable in the ruminal microbe genome at any incubation time. This study implies that the possibility of transformation of Bar and CaMV 35S genes to the ruminal microbes is scarce. © 2013 Copyright Institute of Subtropical Agriculture, Chinese Academy of Sciences.