Groundbreaking poplar study shows trees can be genetically engineered not to spread

The largest field-based study of genetically modified forest trees ever conducted has demonstrated that genetic engineering can prevent new seedlings from establishing. 

The "containment traits" that Oregon State University researchers engineered in the study are important because of societal concerns over gene flow – the spread of genetically engineered or exotic and invasive trees or their reproductive cells beyond the boundaries of plantations.

"There's still more to know and more research to be done, but this looks really good," said corresponding author Steve Strauss, distinguished professor of forest biotechnology at OSU. "It's very exciting."

Findings from the study – which looked at 3,300 poplar trees in a 9-acre tract over seven growing seasons – were published today in Frontiers in Bioengineering and Biotechnology. Poplars are fast growing and the source of many products, from paper to pallets to plywood to frames for upholstered furniture.

In trees like poplars that have female and male individuals, female flowers produce the seeds and male flowers make the pollen needed for fertilization.

Strauss and colleagues in the Department of Forest Ecosystems and Society assessed a variety of approaches for making both genders of trees sterile, focusing on 13 genes involved in the making of flowers or controlling the onset of reproduction.