Study shows chemical compound in latex deters insects

Dandelions are seen as a nuisance in most gardens, but research has found that the latex in dandelions can also deter many different insects which could potentially harm gardens.

The root feeder cockchafer larvae is one such insect that the dandelion is protected against because of the milky, bitter tasting sap that makes up the dandelion latex according to researchers at Max Planck Institute for Chemical Ecology in Jena, Germany, and the University of Bern, Switzerland.

The cockchafer is one of many herbivores the dandelion is susceptible to because the larvae stage feeds on the roots of plants like the dandelion. The dandelion has many defenses other than the latex, but the latex is believed by scientists to be the primary deterrent since concentrations of latex were found to be highest in dandelion roots.

The scientists in Germany and Switzerland tested the latex to see if the compounds were negatively associated with the development of cockchafer larvae. They found that a substance called the sesquiterpene lactone, taraxinic acid-D-glucopyranosyl ester (TA-G) caused the larvae to eat less.

“For me, the biggest surprise was to learn that a single compound is really responsible for a defensive function,” Jonathan Gershenzon, the head of the Department of Biochemistry at the Max Planck Institute in Jena, Germany, said. “The latex of dandelions and other plants consists of such a mixture of substances that it didn’t seem necessarily true that one chemical by itself had such a protective role against our study insect.”

Matthias Erb, the study leader from the University of Bern, said the combination of techniques was crucial for the success of their studies.

“Each approach has its weaknesses that were balanced by the strengths of the others," Erb said. "We think that this type of interdisciplinary research can be very powerful to understand biological systems.”

Organizations in this story

Max Planck Institute for Chemical Ecology Hans-Knöll-Straße 8 Jena, Thüringen - D-07745

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