Featured Research

from universities, journals, and other organizations

A poison as an indicator of food

Date:
November 16, 2011
Source:
NCCR Plant Survival
Summary:
The western corn rootworm represents a formidable pest. But what is the cause of its voracity? Biologists in Switzerland have put forth an explanation. The western corn rootworm larvae exploit the plant’s natural defences, which are supposed to deter them, to their benefit by using them to locate nutrient rich plant parts.

The western corn rootworm represents a formidable pest. But what is the cause of its voracity? Biologists at the University of Neuchâtel, within the framework of a project supported by the National Centre of Competence in Research (NCCR) Plant Survival, have put forth an explanation. The western corn rootworm larvae exploit the plant's natural defences, which are supposed to deter them, to their benefit by using them to locate nutrient rich plant parts.

Related Articles


The results. published in the journal Ecology Letters, open up new avenues for the control of this herbivorous pest.

The western corn rootworm is a real problem for farmers. In the USA, this pest causes about one billion dollars in damages and control measures per year. To this amount a half billion euros yearly can be added on the European continent, which was only recently invaded by the pest. The researchers in Neuchâtel, in collaboration with six other laboratories across the world, have found an explanation for the voracious behaviour of the rootworm on maize. "The plant places its defence priorities on tissues that are valuable to it," states Christelle Robert, PhD student in the FARCE laboratory under the supervision of Ted Turlings.

"These are the most nutrient rich plant organs that are also coveted by herbivorous insects. Logically, it is in these organs that the plant produces the highest concentrations of toxins used to repel or poison pests that feed off them." This strategy can also be seen in maize roots. The most precious of these are called crown roots, which form a crown in the soil that contain valuable nutrients for larvae in search of food.

"Compared to primary and secondary roots, crown roots are richer in sucrose, a substance known stimulate the appetites of insects. They also contain more proteins and free amino acids, of which certain are essential to insects," explains Christelle Robert.

To protect its tissues, maize relies on a fleet of toxic substances that are in most cases very effective. "We showed this in tests with generalists herbivorous insects that can also feed on other plants, specifies the young biologist. However, when we tested the effect of these toxins on corn rootworm larvae, we found something quite different."

The experiments, which were developed by Christelle Robert and Matthias Erb, who is currently at the Max Planck Institute for Chemical Ecology in Jena (Germany), revealed that the larvae not only tolerate the poison, but they even use it to locate the zones rich in nutritional substances, in this case crown roots. Hence, the insects use the toxins, which are supposed to deter them, to their benefit. It is the first time that such a phenomenon has been observed at the plant root level.

To arrive at this surprising conclusion, the researchers made use of a mutant maize plant that is incapable of producing the toxins in question. They offered the rootworm larvae a choice between roots from plants that can produce the toxic substances and those that cannot. Against all expectations, the larvae clearly preferred the plants with an active defence mechanism. Moreover, they observed the larvae on the toxin producing plants would settle on a plant within three hours and would fix themselves to the crown roots permanently. On the other hand, on non-toxic plants, the larvae seemed disoriented and wandered continuously from one type of root to the other.

"We have therefore concluded that the toxins are an indispensable indicator for rootworm in search of food. We also showed that the larvae that fed on crown roots developed better than larvae feeding on primary or secondary roots," states Christelle Robert.

The researchers' next step is to uncover the mechanism that enables the larvae to tolerate the poison. The most promising option are enzymes that the insect produces to detoxify the plant's defence compounds.


Story Source:

The above story is based on materials provided by NCCR Plant Survival. Note: Materials may be edited for content and length.


Journal Reference:

  1. Christelle A.M. Robert, Nathalie Veyrat, Gaétan Glauser, Guillaume Marti, Gwladys R. Doyen, Neil Villard, Mickaël D.P. Gaillard, Tobias G. Köllner, David Giron, Mélanie Body, Benjamin A. Babst, Richard A. Ferrieri, Ted C.J. Turlings, Matthias Erb. A specialist root herbivore exploits defensive metabolites to locate nutritious tissues. Ecology Letters, 2011; DOI: 10.1111/j.1461-0248.2011.01708.x

Cite This Page:

NCCR Plant Survival. "A poison as an indicator of food." ScienceDaily. ScienceDaily, 16 November 2011. <www.sciencedaily.com/releases/2011/11/111116081757.htm>.
NCCR Plant Survival. (2011, November 16). A poison as an indicator of food. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2011/11/111116081757.htm
NCCR Plant Survival. "A poison as an indicator of food." ScienceDaily. www.sciencedaily.com/releases/2011/11/111116081757.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) — In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) — Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) — The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) — A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins