Fused genes tackle deadly Pierce's disease in grapevines

Feb 20, 2012
Expression of a hybrid protein blocks Pierce's disease in a grapevine. The hybrid protein (shown at the bottom right) creates pores in the membrane of the Gram-negative bacterium, Xf, that causes PD. The transgenic grapevine expressing the hybrid protein shows little or no leaf scorching as PD symptom upon Xf infection (top left) whereas the non-transgenic without the hybrid protein shows severe leaf scorching (top right). Credit: Los Alamos National Laboratory

A gene fusion research project led by a University of California, Davis, plant scientist delivers a one-two punch to Pierce's disease, a deadly threat to California's world-renowned wine industry.

The study is set for publication the week of Feb. 20 in the early edition of the .

"Many disease-causing microbes can evade one defensive action by a host plant, but we believe that most microbes would have difficulty overcoming a combination of two immune-system defenses," said UC Davis plant sciences professor Abhaya Dandekar, the lead researcher.

He and his colleagues tested this hypothesis on Xylella fastidiosa, the bacteria responsible for Pierce's disease in . Strains of the bacteria also attack and damage other , including citrus, stone fruits, almonds, oleander, and certain shade trees, such as oaks, elms, maples and sycamores.

The findings further strengthen UC Davis' standing as a world leader in the science of plant improvement through advances in genetics, genomics, plant breeding and biodiversity.

First noted in California near Anaheim around 1884, Pierce's disease in grapevines is now known to exist in 28 California counties. From 1994 to 2000, the disease destroyed more than 1,000 acres of northern California grapevines, causing $30 million in damages. There is currently no known cure for Pierce's disease.

In grapevines, Xylella fastidiosa is carried from plant to plant by half-inch-long insects known as sharpshooters. The bacteria infect and clog the plant's water-transporting tissue, or xylem. Grapevines with Pierce's disease develop yellow and brown leaves and die within a few years.

To block such infections, the researchers engineered a hybrid gene by fusing together two genes that are responsible for two key functions of the plant's : recognizing Xylella fastidiosa as a bacterial invader and destroying its , causing the bacteria to die.

The researchers then inserted this hybrid gene into grapevines.

They found that sap from plants genetically engineered with the hybrid gene effectively killed Xylella fastidiosa in the laboratory. And grapevines engineered to carry the hybrid gene had significantly less leaf scorching and xylem clogging, indicating resistance to Pierce's disease.

Explore further: Chickens to chili peppers: Scientists search for the first genetic engineers

Provided by University of California - Davis

5 /5 (3 votes)

Related Stories

Tiny Wasp Saves Pacific Island Paradise

Jun 21, 2006

It was a tourist bureau’s nightmare. A plant-killing invasive insect establishes a beachhead on a Pacific island paradise and quickly spreads, leaving tourists and locals who stroll down tree-lined promenades ...

Virus-resistant grapevines

Jul 02, 2009

Viruses can cost winegrowers an entire harvest. If they infest the grapevines, even pesticides are often no use. What's more, these chemicals are harmful to the environment. Researchers are growing plants ...

Recommended for you

Deadly human pathogen Cryptococcus fully sequenced

13 hours ago

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Building better soybeans for a hot, dry, hungry world

Apr 16, 2014

(Phys.org) —A new study shows that soybean plants can be redesigned to increase crop yields while requiring less water and helping to offset greenhouse gas warming. The study is the first to demonstrate ...

User comments : 0

More news stories

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.

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Leeches help save woman's ear after pit bull mauling

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

Venture investments jump to $9.5B in 1Q

Funding for U.S. startup companies soared 57 percent in the first quarter to a level not seen since 2001, as venture capitalists piled more money into an increasing number of deals, according to a report due out Friday.