Nav: Home

New insight into why Pierce's disease is so deadly to grapevines

June 08, 2018

Scientists are gaining a better understanding of Pierce's disease and how it affects grapevines. The disease, which annually costs California more than $100 million, comes from a bacterium called Xylella fastidiosa. While the bacterium has been present in the state for more than 100 years, Pierce's disease became a more serious threat to agriculture with the arrival of the glassy-winged sharpshooter insect, which can carry the bacterium from plant to plant.

In a new study, published in Frontiers in Plant Science, researchers at the University of California, Davis, have identified a set of molecular markers that influence the onset of Pierce's disease in grapevines.

"We now have a very good idea of the plant responses to the disease," said lead author Paulo Zaini, a postdoctoral researcher in the Department of Plant Sciences at UC Davis. "This will help us in early diagnosis and help us design strategies to protect the plant from damaging itself."

HOW INFECTION DEVELOPS

The glassy-winged sharpshooter injects the Xylella fastidiosa bacterium into the plant's xylem, which is the part of the plant that carries water. The disease causes leaves to yellow or "scorch," eventually drying up and dropping from the vine. It can kill a plant in three to five years. Few diseases can kill grapevines so quickly.

The glassy-winged sharpshooter was first reported in California in 1994 and can travel greater distances than native sharpshooters. By 2002, the glassy-winged sharpshooter had infested more than 1,100 acres of grapevines statewide.

"What growers do to stop the bug is just apply insecticides at an increasingly growing rate," said Zaini. "It's not a sustainable strategy."

In this study the authors looked at the plant's responses to the disease compared to healthy plants. Better understanding the biochemical changes with onset of the disease can help foster new strategies to increase plant health, rather than having to use insecticides to fight disease.

Scientists have long thought the bacteria growing in the xylem blocked the flow of water to the leaves.

"We thought that the blockage causes a drought stress, but there's much more to it than that." said Abhaya Dandekar, professor of plant sciences and the study's principal investigator. "Not all the vessels are blocked."

The blockage might be part of the problem, but it doesn't answer all the questions. More than 200 plant species harbor the bacterium but are asymptomatic.

Having identified molecular markers important for Pierce's disease in grapevines, researchers can use them to study grapevine varieties or other plants that do not develop disease.
-end-
Co-authors include Hossein Gouran, Sandeep Chakraborty, and My Phu with the UC Davis Department of Plant Sciences; Dario Cantu with the UC Davis Department of Viticulture and Enology; and Rafael Nascimento and Luiz Goulart with the Institute of Genetics and Biochemistry at the Federal University of Uberlandia in Brazil.

The study was funded by the California Department of Food and Agriculture Pierce's Disease Board and CAPES, a Brazilian scientific research funding agency.

University of California - Davis

Related Bacterium Articles:

The cholera bacterium can steal up to 150 genes in one go
EPFL scientists have discovered that predatory bacteria like the cholera pathogen can steal up to 150 genes in one go from their neighbors.
Exploiting green tides thanks to a marine bacterium
Ulvan is the principal component of Ulva or 'sea lettuce' which causes algal blooms (green tides).
The cholera bacterium's 3-in-1 toolkit for life in the ocean
The cholera bacterium uses a grappling hook-like appendage to take up DNA, bind to nutritious surfaces and recognize 'family' members, EPFL scientists have found.
Excellent catering: How a bacterium feeds an entire flatworm
In the sandy bottom of warm coastal waters lives Paracatenula -- a small worm that has neither mouth, nor gut.
Russian scientists found out how a male-hating bacterium rejuvenates
A team from Immanuel Kant Baltic Federal University together with their Russian colleagues carried out genetic analysis of the symbiotic bacterium Wolbachia that prevents the birth and development of males in different species of arthropods.
Cancer prevention drug also disables H. pylori bacterium
A medicine currently being tested as a chemoprevention agent for multiple types of cancer has more than one trick in its bag when it comes to preventing stomach cancer, Vanderbilt researchers have discovered.
A social bacterium with versatile habits
Related individuals of a soil bacterial species live in cooperative groups and exhibit astonishing genetic and behavioral diversity.
Novel potent antimicrobial from thermophilic bacterium
University of Groningen microbiologists and their colleagues from Lithuania have discovered a new glycocin, a small antimicrobial peptide with a sugar group attached, which is produced by a thermophilic bacterium and is stable at relatively high temperatures.
How a certain bacterium communicates and makes us sick
Researchers at Binghamton University, State University of New York have uncovered the unique way in which a type of Gram-negative bacterium delivers the toxins that make us sick.
The potentially deadly bacterium that's on everyone's skin
Forget MRSA and E. coli, there's another bacterium that is becoming increasingly dangerous due to antibiotic resistance -- and it's present on the skin of every person on the planet.
More Bacterium News and Bacterium Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.