Red alert! How disease disables tomato plant's 'intruder alarm'

Dec 04, 2008

How a bacterium overcomes a tomato plant's defences and causes disease, by sneakily disabling the plant's intruder detection systems, is revealed in new research out today (4 December) in Current Biology.

The new study focuses on a pathogen which causes bacterial speck disease in tomato plants. This bacterial invasion causes black lesions on leaves and fruit. Severe infection can cause extensive and costly damage to tomato crops, and researchers believe that understanding more about how this microbe works could lead to new ways of tackling it, and other plant diseases, without the need for pesticides.

Scientists have found that the pathogen is very effective at attacking tomato plants because it deactivates and destroys receptors which normally alert the plant to the presence of a dangerous disease - in the same way that an intruder would deactivate the burglar alarm before gaining entry to a house.

Professor John Mansfield from Imperial College London's Department of Life Sciences, one of the authors of the paper, says: "Once the receptors have been taken out, the plant's defences are 'offline' and the bacterium is able to spread rapidly, feeding on the plant without encountering any kind of resistance."

Together with colleagues at the Max Planck Institute in Cologne and Zurich-Basel Plant Science Centre, Professor Mansfield used an experimental model plant called Arabidopsis, which is also affected by the disease, to examine what happens at the molecular level when bacterial speck infects a plant. The team found that the pathogen injects a protein into the host cell, which then deactivates and destroys, from the inside, receptors on the cell's surface which are designed to alert the plant to the presence of invading microbes.

Deactivating the receptors stalls the plant's defence mechanism in its initial stages - ordinarily the cell surface receptors would kickstart a chain reaction leading to the production of antimicrobial compounds to fight and kill off the bacterial invader.

Professor Mansfield says: "This area of research has a wider significance beyond black speck disease in tomato, because the microbes that cause plant diseases probably all employ similar attacking strategies to suppress resistance in their hosts. The more we understand about how the pathogens that cause disease overcome the innate immunity to infection in crop plants, the better our chances of developing approaches to disease control that do not require the use of potentially harmful pesticides."

Source: Imperial College London

Explore further: Japan to continue scientific whaling in Pacific: reports

add to favorites email to friend print save as pdf

Related Stories

A pest management toolbox to reduce pesticide use

Apr 02, 2014

Integrated pest management gains momentum due to European regulations on pesticides reduction. But the challenges are to integrate all alternative methods and to get farmers involved.

The genome of sesame sheds new lights on oil biosynthesis

Mar 07, 2014

Researchers from Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, BGI, University of Copenhagen and other institutes have successfully cracked the genome of high oil content crop sesame, providing ...

Priming plant defenses with aspirin-like compound

Feb 14, 2014

For thousands of years, humankind has extracted salicylic acid from willow tree bark to alleviate minor pain, fever, and inflammation. Today, it's used in acne medication and wart removers, among other cosmetic ...

Bumper harvest for GM purple tomatoes

Jan 27, 2014

GM purple tomatoes developed by John Innes Centre scientists in the UK are being harvested in Ontario, Canada, for future research and to attract interest from private investors.

Recommended for you

Scientists tether lionfish to Cayman reefs

29 minutes ago

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

11 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 ...

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 ...

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

Six Nepalese dead, six missing in Everest avalanche

At least six Nepalese climbing guides have been killed and six others are missing after an avalanche struck Mount Everest early Friday in one of the deadliest accidents on the world's highest peak, officials ...

White House updating online privacy policy

A new Obama administration privacy policy out Friday explains how the government will gather the user data of online visitors to WhiteHouse.gov, mobile apps and social media sites. It also clarifies that ...