Crop Biotech Update

GM Crops Pass Benefits to Weeds

August 28, 2013

A study led by ecologist Lu Baorong from Fudan University in Shanghai shows that a weedy form of the common rice crop Oryza sativa gets a significant fitness boost from glyphosate resistance even in the absence of glyphosate. In a study published this month in New Phytologist, Lu and his colleagues genetically modified  cultivated rice species to overexpress its own EPSP synthase, and cross-bred the modified rice with a weedy variety. EPSP synthase is an enzyme blocked by glyphosate to inhibit plant growth.

The cross-bred offspring was allowed to breed with one another, and a second generation set of hybrids that were genetically identical to one another was created. The results showed that those plants with more copies expressed higher levels of the enzyme and produced more of the amino acid tryptophan than their unmodified counterparts. The transgenic hybrids had higher rates of photosynthesis, grew more shoots and flowers, and produced 48 to 125 percent more seeds per plant than non transgenic hybrids in the absence of glyphosate.

For more details about this research, read the Nature news article available at: http://www.nature.com/news/genetically-modified-crops-pass-benefits-to-weeds-1.13517.