I hate mowing the lawn. So finding out that while I’m mowing the grass is desperately releasing a chemical signal to summon parasitic wasps to attack me just gives me another excuse to put it off. If you can still see your feet, it’s fine, right?
Yes, scientists at Texas A&M have built upon early research the recognized the smell of cut grass as a distress signal, figuring out exactly what the grass is signalling.
“When there is need for protection, the plant signals the environment via the emission of volatile organic compounds, which are recognized as a feeding queue for parasitic wasps to come to the plant that is being eaten and lay eggs in the pest insect,” said Dr. Michael Kolomiets, Texas A&M AgriLife Research plant pathologist in College Station.
With your lawnmower you’re probably safe, because the grass hasn’t evolved a defense against that. Yet.
Scientists painstakingly isolated the specific molecular signal, known as the green leaf volatile, plants like grass use to summon the protective wasps. They created mutant corn plants without the green leaf volatile and found they could mutilate them to their liking without signalling the wasps.
“We have provided genetic evidence that green leafy volatiles have this dual function — in the plant they activate production of insecticidal compounds, but also they have indirect defense capability because they send an SOS-type signal that results in attraction of parasitic wasp,” Kolomiets said.
Of course, figuring out the way these signals work is much more than scary trivia. Knowing the mechanism plants use to protect themselves will help scientists develop plant strains that are more resistant to insects and drought.
[Source: Agrilife Today]
Photo via Wikimedia Commons