Scientists produce GM crops without foreign genes

Tobacco plants
Flickr/IanHaskin
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Scientists have unveiled a new way of altering the genetic sequence of a crop to produce a desired trait without needing to introduce foreign genes.
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The technique could be less controversial than conventional genetic modification because it does not involve transferring a gene from another species.
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Scientists used a set of enzymes to "subtly change" a tobacco plant's DNA to make it herbicide resistant.
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The enzymes — known as zinc finger nucleases — can be engineered in the lab to target specific genes, introducing changes known to cause the desired trait.
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Until now there has been no efficient way of making such changes to plant genes.
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Daniel Voytas, director of the US-based University of Minnesota Center for Genome Engineering and the lead author of the research says:
"We changed a few letters in the genetic code of a native plant gene and made the plant resistant to herbicide.
In most genetically modified crops, herbicide resistance is conferred by adding a foreign gene, usually from bacteria."
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The researchers hope the technique will revolutionise how crops are genetically modified.
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"We need to test this technology and compare it with traditional methods of gene transfer.
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I think ... precise DNA sequence modifications that do not introduce foreign DNA will be preferred over traditional approaches," Voytas told SciDev.Net.
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Voytas says the technique requires only standard molecular biology laboratories and competence in introducing DNA into plants — resources that are available in many parts of the developing world.
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He also says capacity to do such work should be increased in developing countries.
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Kamonji Wachiira, an environmental consultant based in Ottawa, Canada, says the technique sounds promising but seems to be largely untested.
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There are also concerns about its effectiveness, and the usual biosafety issues associated with genetic modification, says Wachiira.
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He adds that the zinc finger nucleases could have unpredictable effects on several genes.
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"The new trait may well be accompanied by latent, recessive or unintended but risky traits."
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The research was published in April in Nature.

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Link to full article in Nature

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Kimani Chege
SciDev