Sep 30, 2005

Modified Plants Attract BeneficialsSource: National Geographic

Nationalgeographic.com recently reported a new genetically modified plant – a type of small mustard plant (Arabidopsis thaliana) – was able to attract predatory bugs after researchers inserted a gene from a strawberry plant into its DNA. Arabidopsis thaliana is the first plant to have its entire genome sequenced and is regularly used in plant research. Study co-author Harro Bouwmeester, a biochemist at Plant Research International at Wageningen University in the Netherlands, said the plant needed little genetic modification to introduce the chemical lure. The genetically modified version of the weed may lead to a new method of crop pest control that reduces the need for chemical pesticides.

The article explained that the genetically engineered plant was able to attract predatory mites (a small relative of spiders) that prey on spider mites. The active ingredient varies somewhat between plant species, but most bug attractants rely on complex compounds called terpenes. “You will know terpenes from the smell of certain herbs like peppermint,” Bouwmeester said. “Other plants also produce these compounds, but in lower concentrations so we don’t smell them,'” stated the article. Corn, apples, beans, cucumbers and cotton are a few plants that already produce small amounts of terpenes.

In the article Bouwmeester added that these bodyguard-attracting compounds work best when emitted by the plants themselves, and spraying crops with similar man-made chemicals would not be as effective because of the delicate balance of interactions between plant, pest and predator. Besides, Bouwmeester emphasized that these predators should be attracted at the exact moment the predator’s food source, such as the spider mite, is there.