SciDev.Net

Farmer and tobacco plants

United States Department of Agriculture Photo by: Ken Hammond

Scientists have devised a technique that could prevent the flow of transgenic genes into non-biotech crops — and might end the long-standing debate on terminator genes.

The development could free poor farmers from dependence on companies that sell genetically modified (GM) seeds, suggest the researchers.

The GM-gene-deletor system successfully removed transgenic genes from the seeds and pollen of GM tobacco.

If this technique is applied successsfully to other crops, it could allow farmers to grow non-transgenic and fully viable plants using seeds or pollen from GM plants — unlike the terminator gene system, which makes the plants infertile.

Terminator genes are inserted into GM seeds as a way to protect the companies' patents and ensure that no genes from GM crops contaminate non-GM crops.

But for farmers in developing countries, this means  they have to buy the seeds every year (see: 'Terminator' GM technology stays banned — for now).

The scientists designed specific recognition sites to add around the foreign genes, targetting them for excision. By incorporating these into the genome of GM tobacco plants, the scientists found that all unwanted genes were removed from the pollen and seed with as much as 100 per cent efficiency under glasshouse conditions.

Yi Li and his team at the US-based University of Connecticut and collaborators at the University of Tennessee, United States, and the Southwest University, China, published their results in the Plant Biotechnology Journal on 26 January.

According to Mohammed Gebriel, an Egyptian biotechnologist at the Belgium-based Ghent University, the GM-gene-deletor system could free poor farmers from this dependency on multinational companies. He said it could also protect farmers' tradition of sharing seeds to improve crop varieties, as buying sterile seeds made this impossible.

The gene-deleting technique also provides an important step towards tackling the environmental and health issues raised against GM crops, including consumer concerns over GM food, Gebriel told SciDev.Net.

Reference:
Plant Biotechnology Journal  doi:10.1111/j.1467-7652.2006.00237.x