Biotech Updates

Purdue and USDA Scientists Find a Way to Stop Hessian Fly Attacks

December 16, 2011

Developing genetic resistance to Hessian flies has been a challenge both for wheat and the scientists. Thirty three genes have been identified to provide resistance to the pest but they are currently not giving favorable results. U.S. Department of Agriculture and Purdue University scientists are optimistic that they will soon be able to find a solution to this problem. They have developed a technique for testing toxins from other plants on Hessian fly larvae, which simulates the effect of a genetically engineered plant without actually undergoing the expensive and time-consuming procedures involved in creating those plants.

Toxins that could kill the flies is tested by using an artificial diet and feeding assay. However, the flies are not taking the bait so the scientists had no other choice but to produce transgenic lines of wheat and feed them to the flies. And then finally, they thought of an easier way to get things done. To get the toxins into the larvae, scientists allowed the flies to lay eggs on leaves of wheat seedlings. When the eggs hatched, the plants were removed from the soil and transplanted as hydrophonics with toxic proteins added to the plant's water. When the fly larvae attacked and fed as usual, they also ingested the toxins that came from the water.

"The plant is just acting like a big straw taking up the toxins," said Christie Williams, scientist from USDA and one of the authors of the study. "It's just like putting a carnation into a cup of colored water and watching the flower change colors."

Protein immunoblot detection tests have confirmed that the larvae had consumed the toxins. They tested nine toxins that disrupt the digestive system of the larvae and found that the snowdrop lectin from a flowering plant is the most effective in hampering the growth of the larvae.

The research team plans to develop transgenic version of the wheat for further testing.

Read the complete story at http://www.purdue.edu/newsroom/research/2011/111212ShukleTransgenic.html.