Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Deadly plant bug sequenced

31.01.2002


Researchers grapple with wilt-causing bacteria


Southern wilt affects more than 200 species around the world.
© D. Gay


An infected cutting. The microbe can wipe out entire fields.
© D. Gay



It’s the Mike Tyson of plant bacteria," says Gerry Saddler, of the Scottish Agricultural Science Agency, Edinburgh.

Saddler is referring to Ralstonia solanacearum, the cause of southern bacterial wilt possibly the most important plant disease in the world. French researchers have now sequenced the bacteria’s genome - information that should lead to a better understanding of plant disease, and perhaps new ways to fight it1.


Southern wilt or brown rot affects more than 200 species around the world, including potatoes, bananas, mulberry trees and ginger. Entering plants through their roots, Ralstonia mounts a deadly assault on their fluid and nutrient transport networks.

The bacterium’s genome sequence gives some clues to its versatility. An unusually large number of genes enable it to attach to plant cells and inject them with its proteins. It may use different genes on different host species.

Finding the plant molecules that these two processes latch onto, "might allow us to engineer resistant varieties," says Christian Boucher of the National Agronomic Research Institute in Toulouse who led the sequencing project.

The genome should also provide insight into many other plant diseases that employ similar infection strategies. "It’ll revolutionize molecular plant pathology," says plant biologist James Alfano of the University of Nebraska, Lincoln.

Off switch

Knowing the genes that cause disease might also allow us to switch them off. Ralstonia can do this itself, and live in plants without harming them.

Julian Smith, of CABI Bioscience in Egham, England, is trying to engineer benign forms of the bacterium with which to inoculate plants against the lethal form. Early results are promising, and the team has permission, but not funds, to run trials in Kenya and South Africa.

Other potential routes of attack are the genes that Ralstonia use to make chemicals to kill each other, says Smith. Engineering these into potato plants "could have enormous applications", he says.

Rotten luck

At present there is little we can do to combat Ralstonia aside from try to prevent its spread. Conventional plant breeding has largely failed to create resistant crops - perhaps because the bacterium uses many genes to bring about disease. The bug’s wide host range and ability to survive in the soil for several years makes it difficult to evade by crop rotation.

The microbe can wipe out entire fields. In parts of Florida, for example, it has killed 75% of the potato crop. "Fields got so heavily infested that people abandoned them," says plant pathologist Tim Denny of the University of Georgia, Athens.

Ralstonia prefers warm weather, but a cold-tolerant strain from Andean potatoes reached Europe and North America in the 1990s. This strain can spread via rivers and has since infected wild plants, where it does no harm.

Seed-potato distribution is now tightly monitored. "People are very concerned that the pathogen might escape," says Denny. Global warming might be aiding its spread.

References


  1. Salanoubat, M. Genome sequence of the plant pathogen Ralstonia solanacearum. Nature, 415, 497 - 502, (2002).


JOHN WHITFIELD | Nature News Service

More articles from Life Sciences:

nachricht A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>