Student Research Spotlight - Asher Jones
Posted: May 27, 2016
“Rescue me!”- Plants call parasitoids for help
By Bipana P. Timilsena
We all have seen animals and insects expressing their emotions by producing different sounds, but you might be surprised to learn that plants can also communicate with each other and other organisms, too.
“Plants are capable of a sophisticated exchange of information with their defenders even though they don’t possess eyes, ears, or a brain,” says Asher Jones, a graduate student at Penn State.
Plants have very complex relationship with the insects that eat them (herbivores) and the insects that eat herbivores (parasitoids). When a plant is being attacked by an herbivore (such as a caterpillar), it releases airborne chemicals that attract parasitoids (such as wasps). The parasitoids then locate the herbivores and lay their eggs in them. Eventually, the eggs hatch and the developing larvae eat the herbivore, saving the plant from further damage.
Chemicals in the caterpillar's saliva alert the plant to the presence of the herbivore, and cause it to release the parasitoid-attracting chemicals.
“However, once a caterpillar has been parasitized by a wasp, we don't know if or how the caterpillar's saliva might change,” says Jones. According to Jones, since parasitoids don’t interact directly with plants, changing the compounds in the spit of their caterpillar hosts might be a way of telling plants that the parasites have “arrived” so that the plants can reduce production of the signaling chemicals. This could be beneficial to plants, since these chemicals are costly to produce. This could also be beneficial for the parasitoids by halting attraction of further parasitoids, since their offspring’s survival is reduced if multiple females lay eggs in the same host.
Under supervision of Dr. Gary W. Felton and Dr. Kelli Hoover, Jones plans to compare the chemical profiles of unparasitized and parasitized caterpillars, and evaluate their impact on plant signaling systems.
Jones’s research could open a new platform for those who work on ecology and sustainability. She says, “Better understanding of the interactions between pests, plants and their natural defenses like parasitoid wasps is important for developing more environmentally friendly pest management techniques that use less pesticides.”