Virus component helps improve gene expression without harming plant

Nov 12, 2010

( -- A virus that normally deforms or kills plants like tomatoes, peppers and eggplants isn't all bad: A gene within the virus has been found useful for allowing foreign genes to be introduced into a plant without harmful effects, according to Texas AgriLife Research scientists.

The technology ultimately could lead the way toward a "cheap, green alternative" for pharmaceutical development, said Dr. Herman Scholthof, AgriLife Research virologist.

Scholthof and colleague Drs. Yi-Cheng Hsieh and Veria Alvarado collaborated with scientists at the John Innes Centre in England on the study which appears in this week's Plant Biotechnology Journal.

"Nowadays in the pharmaceutical industry, many protein-based drugs are expressed in and purified from bacteria," Scholthof said. "Plants not only form a cheap and green alternative, but they also have the benefit that they process proteins properly -- something can not do."

The team worked with tomato bushy stunt , which can attack a multitude of plants worldwide but rarely has economically severe consequences. It is model virus that can be safely contained because it does not have an insect vector which could spread it.

For this study, Scholthof said, only one gene of the virus -- called P19 -- was used because it is the one that suppresses RNA silencing.

"RNA silencing is a fairly recently discovered defense that plants use against viruses," he explained. "During this silencing, short strands of serve as signals to alert the plant that a virus is attempting to infect so that all of its tissues start mobilizing to defend.

"The elegance is that the P19 protein forms counter-defense units that are each composed of two which form a sort of caliper to measure and capture signal molecules, thereby suppressing the defense to the virus which can infect a plant."

But suppressing the defense might also allow other things, such as allowing desired genes to enter and be expressed. Scholthof said scientists have used other suppressors in plant research in the past to avoid silencing, but "a problem is that these suppressors also cause many developmental defects and severe disease symptoms."

Not so with the P19 variant the group developed, he said.

Scholthof said the process of expressing foreign genes in plants is common in research, but there also is an important practical use.

"It also is used in biotechnology to produce beneficial proteins for medical and veterinary applications," he noted. "By developing this new P19, we have 'tamed' a suppressor because it still works to suppress but does not induce severe disease symptoms in the plant.

"We have provided a proof-of-principle that P19 can be used to protect the silencing of introduced foreign in ."

Explore further: Heaven scent: Finding may help restore fragrance to roses

Related Stories

People also have antiviral 'plant defences'

Sep 27, 2010

In addition to known antiviral agents such as antibodies and interferons, people also seem to have a similar immune system to that previously identified in plants. This is the result of research carried out by Esther Schnettler ...

What genes help blossoms last longer?

May 24, 2010

Some cut flowers and potted plants are better than others at fending off the aging process, known as senescence. To help tomorrow's blooms stay fresh longer, Agricultural Research Service (ARS) plant physiologist Cai-Zhong ...

Plant virus spreads by making life easy for crop pests

Oct 30, 2008

( -- 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, ...

Genes identified to protect brassicas from damaging disease

Nov 01, 2007

Scientists have identified a new way to breed brassicas, which include broccoli, cabbage and oilseed rape, resistant to a damaging virus. Their discovery has characterised a form of resistance that appears to be durable, ...

Recommended for you

Study on pesticides in lab rat feed causes a stir

Jul 02, 2015

French scientists published evidence Thursday of pesticide contamination of lab rat feed which they said discredited historic toxicity studies, though commentators questioned the analysis.

International consortium to study plant fertility evolution

Jul 02, 2015

Mark Johnson, associate professor of biology, has joined a consortium of seven other researchers in four European countries to develop the fullest understanding yet of how fertilization evolved in flowering plants. The research, ...

Making the biofuels process safer for microbes

Jul 02, 2015

A team of investigators at the University of Wisconsin-Madison and Michigan State University have created a process for making the work environment less toxic—literally—for the organisms that do the heavy ...

Why GM food is so hard to sell to a wary public

Jul 02, 2015

Whether commanding the attention of rock star Neil Young or apparently being supported by the former head of Greenpeace, genetically modified food is almost always in the news – and often in a negative ...

The hidden treasure in RNA-seq

Jul 01, 2015

Michael Stadler and his team at the Friedrich Miescher institute for Biomedical Research (FMI) have developed a novel computational approach to analyze RNA-seq data. By comparing intronic and exonic RNA reads, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.