Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Virus pulls bait and switch on insect vectors

02.02.2010
A common plant virus lures aphids to infected plants by making the plants more attractive, but when the insects taste the plant, they quickly leave for tastier, healthier ones. In the process, the insects rapidly transmit the disease, according to Penn State entomologists.

"The virus improves the cues that insects use to identify food by elevating some aspect of a trait that is already in the plant," said Mark C. Mescher, assistant professor of entomology. "In this case they appear to elevate the odor cue, without changing it."

This type of host alteration has implications beyond agriculture. If pathogens can alter hosts to make transmission more efficient, they may be doing it in such insect-transmitted human diseases as malaria or dengue fever.

Some plant viruses entice insects to visit infected plants and stay awhile, incorporating the virus into the insect's system. Then, when they fly to another plant, they transfer the virus. This is a persistent mode of transmission because the plants will infect all the subsequent plants the insects dine on. However, the insects needed to spend a sizable amount of time on the original infected plant.

The researchers are looking at the cucumber mosaic virus because it is not a persistent virus. Insects pick up the virus when they take their first taste of leaf. The virus binds chemically to mouth parts and when the insect feeds on another leaf, the virus is transferred, but in most cases only to the first plant and not to subsequent ones, making this a non-persistent virus. They reported their findings in this week's online Proceedings of the National Academy of Sciences.

"Viruses like these (non-persistent ones) use a different system to ensure transmission," said Kerry E. Mauck, graduate student in entomology. "They have not been examined as closely as persistent systems."

Aphids transmit cucumber mosaic virus, which will infect the entire squash family of plants. The researchers investigated two species of aphids that can transmit the virus, one that prefers squash but will eat other things, and one that prefers turnips but will also eat squash. They used a special insect arena developed for testing aphid responses to plant odors. The aphids could not see or alight on the plants so they did not have color or taste cues. The insects could only access the chemicals the plants released into the surrounding air.

"We wanted to see where they aggregated most often," said Mauck. "They tended toward the plants that were infected rather than the healthy leaves."

Mauck, Mescher and Consuelo De Moraes, associate professor of entomology, next tested the aphids to see which plant allowed them to reproduce the best. They found that the aphids reproduced less well on the infected plants than they did on the healthy plants.

Next the researchers tested the aphids to see how long they stayed on infected or healthy plants. While the sick plants initially attracted the aphids, probably because of the increased odor cues, the insects remained on the healthy plants much longer.

"We demonstrated that there were attraction cues combined with a repellant response when the plant was eaten," said Mauck. "We used two species of aphid to ensure that it was not a fluke that one aphid behaved this way."

The researchers have not done a time study to see how many aphids actually visit sick and healthy plants over time. All the studies so far have been only a snapshot in time. They have tested the sick plants and determined that these plants produce much more volatile chemicals than healthy plants, but that the chemicals are the same as those produced by healthy plants.

"If the viruses caused the sick plants to produce altered volatile cues, then the insects could learn how the sick plants smelled and avoid them," said Mescher. "Because the virus only increases the amount of chemicals, there may be no way for the insects to distinguish between sick and healthy plants until they feed on them."

Mescher notes that the team is working on similar questions in human disease systems.

"We know that malaria-infected people are more attractive to malaria-transmitting mosquitoes," said Mescher. "We do not know if the same principles as in cucumber mosaic virus apply to malaria, but we are working on it."

The U.S. Department of Agriculture supported this work.

A'ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu

Further reports about: Virus Virus pulls agriculture healthy plants insect vectors plant virus

More articles from Life Sciences:

nachricht Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

nachricht First transcription atlas of all wheat genes expands prospects for research and cultivation
17.08.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>