GE Epsps Gene from Rice Increases Productivity of Weedy-rice Hybrids without Herbicide Application

Fudan University scientist Bao-Rong Lu investigated the fitness effect of genetically engineered native epsps gene on crop-weed lines of rice. He examined the expression of the gene, field performance, and physiological traits of rice lines derived from hybrids between the epsps transgenic rice (EP3) and four weedy rice varieties. He also aimed to analyze the possible effect of the transgene if it transfers to weedy rice plants through gene flow.

The experiment showed that plants of the four transgenic crop-weed lines had increased levels of plants of the four transgenic crop-weed lines. The transgenic crop-weed lines also had higher levels of EPSPS protein than non-transgenic plants. Lu also observed that that transgenic F2 crop-weed hybrid plants showed better performance than their non-transgenic counterparts, even without treatment with glyphosate herbicides. Furthermore, the leaves of F2 plants had greater tryptophan concentrations and photosynthetic rates compared with the non-transgenic controls.

Based on the findings, over-expression of the native epsps gene from rice can lead to significant fitness advantages in weedy hybrid lines, even if the plants were not exposed to glyphosate. This implies that the spread of epsps transgene from transgenic rice to wild rice populations that are not exposed to glyphosate may also have increased fitness performance leading to undesired environmental impacts. On the other hand, over-expression of engineered epsps may provide opportunities to increase crop production, if no wild relatives are in the vicinity of the transgenic crop.

Read the research article at ISB News Report: http://www.isb.vt.edu/news/2013/Oct/Lu.pdf.