The Guardian reports that a British field trial of a GM wheat that was designed to repel aphids has found the crop to have no better protection than conventional wheat. The trials compared aphid attacks on standard wheat plants with those suffered by a GM variety that had been modified to release a natural aphid repellant – E-beta-farnesene.
According to the G, the crop’s failure to resist the bugs has not surprised everyone. Jonathan Gershenzon at the Max Planck Institute for Chemical Biology in Jena, found in 2010 that GM plants designed to release EBF did not repel aphids, at least under lab conditions. The reason, he suspects, is that the plants released the chemical continuously rather than in short pulses.
Commenting on the Rothamsted trial, Gershenzon told the Guardian:
“I would have bet that it wouldn’t work based on our published study. Our major conclusion was that this strategy doesn’t work in nature because the aphids get used to the continuous release of their alarm pheromone and thus learn to ignore it. Or, they’re programmed to respond only to bursts of it, which would be the natural situation when one of their sisters is attacked. Or both. I can imagine that the authors were misled because the application of the alarm pheromone ‘worked’ in laboratory experiments to repel aphids. Like many workers before them they probably applied the pheromone in an unnatural way so that the dose was much higher than seen under more natural conditions. So it was very important that they were able to test this in the field, to answer a basic scientific question as well as to look for agricultural benefits. This was a noble, but expensive try."
This post, from the Aphid Room, adds complexity to this tale. Meanwhile, the Soil Association's Director of Policy says he told you so:
"The GM wheat trial at Rothamstead was a waste of time and money whether it worked or not. As many people said when the trial was first announced, aphids are not a significant problem on wheat crops in the UK, which is confirmed by the fact that organic farmers, using no insecticides, do not have significant problems with aphids attacking their wheat crops, with no use of pesticides. One reason the trial appears to have failed is that there weren't 'enough aphids' to attack the wheat, which just goes to show that the original criticisms of the trial, that it was unnecessary in the first place, were right. A total of £2.97 million of public money (the cost of the research and security measures) has been wasted on this research - meanwhile, British farmers face numerous practical problems from the continuing losses of soil to the emergence of weeds resistant to weed killing chemicals which deserve priority for scarce research funding."
This £2.97m cost is worth disaggregating. The research cost £730,000; £400,000 was spent on fencing to protect this and future trials, and an extra £1.8m was spent to combat threats of criminal damage and vandalism from those opposed to GM, to trials (or both).
What a pity for the tax-payer (and farmers) that so many people are prepared to wreck scientific studies because they are not willing to have their ideas properly tested. Just wary of the outcome, I guess.
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