Plant virus spreads by making life easy for crop pests

Oct 30, 2008
Deformed and defenseless. New research shows how a virus deploys a single molecule, βC1, to turn a healthy tobacco plant (left) into a deformed and sterile one (right). The molecule also tricks the plant into lowering its defenses against the pests that spread the virus.

(PhysOrg.com) -- In 752, Japanese Empress Koken wrote a short poem about the summertime yellowing of a field in what is thought to be the first account of a viral plant disease. More than 1,250 years later, scientists concluded that the virus Koken described was part of the particularly insidious geminivirus family that continues to decimate tomato, tobacco and cotton crops worldwide. Now, new research shows how cunning an enemy one of these ancient viruses can be, manufacturing a protein that deforms and sterilizes plants and at the same time wrecks their defenses against the pests that spread the disease to others.

Researchers at The Rockefeller University have found that βC1, a toxic protein produced by the tomato yellow leaf curl China virus (TYLCCV), mimics the behavior of one of two different molecules that govern the development of leaf shape and vein structure. In doing so, it throws the plants off course, causing the unseemly curling and crumpling of leaves and the production of sterile flowers. But it also suppresses the plants’ jasmonic acid response, a defense mechanism against pests feeding on the plants. The result is that the pests — in this case whiteflies that plague tobacco plants — flourish in the diseased crop, spreading the virus faster and faster. Nam-Hai Chua, Andrew W. Mellon Professor and head of the Laboratory of Plant Molecular Biology, and his colleagues published the work in Genes and Development.

“This is a new way to look at the relationship between viruses, plants and vectors,” says Jun-Yi Yang, a postdoc in Chua’s lab who did the research. “If you just look at viruses and host plants, you can’t explain why the whiteflies tend to congregate on infected plants. Our research explains how the disease can spread so fast.”

The researchers inserted a gene that produces βC1 into Arabidopsis plants, model organisms for studying plant biology. The plants grew up with symptoms very similar to those of tobacco plants infected with TYLCCV. Yang and colleagues found that these mutants had the same problems as plants that overproduced a protein known as Asymmetric leaves 2 (AS2), which along with Asymmetric leaves 1 (AS1), regulates crucial elements of a plant’s development. In effect, βC1 poses as AS2 and interacts with AS1, upsetting the healthy development of plants. But it also weakens the response of genes that normally boost the jasmonic acid defense against the threat of an invasive pest, the researchers found.

The discovery of how a toxic protein manipulates the relationship of the plant and the whitefly to favor the virus could lead to a more comprehensive strategy for fighting the disease. “You need to fight against both viruses and insect vectors,” Yang says. “If you can increase the jasmonic acid response, you’ll have a better chance against whiteflies.”

Citation: Genes and Development 22: 2564–2577 (September 2008)

Provided by Rockefeller University

Explore further: For resetting circadian rhythms, neural cooperation is key

add to favorites email to friend print save as pdf

Related Stories

Wireless power transfer achieved at five-meter distance

1 hour ago

The way electronic devices receive their power has changed tremendously over the past few decades, from wired to non-wired. Users today enjoy all kinds of wireless electronic gadgets including cell phones, ...

Rapid and accurate mRNA detection in plant tissues

1 hour ago

Gene expression is the process whereby the genetic information of DNA is used to manufacture functional products, such as proteins, which have numerous different functions in living organisms. Messenger RNA (mRNA) serves ...

Israeli team eyes jellyfish for super-absorbent material

Apr 11, 2014

(Phys.org) —If diapers choke landfills and sea creatures plague tourism and invade power stations, an Israeli startup seeks to promote a single answer to both problems, according to The Times of Israel re ...

Recommended for you

Researchers develop new model of cellular movement

2 hours ago

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

User comments : 0

More news stories

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Scientists tether lionfish to Cayman reefs

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

Under some LED bulbs whites aren't 'whiter than white'

For years, companies have been adding whiteners to laundry detergent, paints, plastics, paper and fabrics to make whites look "whiter than white," but now, with a switch away from incandescent and fluorescent lighting, different ...