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

December 4, 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: These foods will lower your risk of heart disease

Related Stories

These foods will lower your risk of heart disease

November 6, 2017

Low-fat or low-carb? Butter or margarine? Avocado oil or coconut oil? Bombarded with contradictory media reports on the ever-changing landscape of nutrition research, it's difficult for anyone to know which fats and other ...

Plant-based diet associated with lower heart failure risk

November 14, 2017

Eating a mostly plant-based diet was associated with less risk of developing heart failure among people without previously diagnosed heart disease or heart failure, according to preliminary research presented at the American ...

Potato blight's chemical attack mechanism explained

December 15, 2017

A team of international researchers headed by scientists from the University of Tübingen has deciphered the workings of a cytolytic toxin, which is produced by some of the world's most devastating crop diseases. The Cytolysin ...

Northeast farmers weigh warming climate, drenched fields

December 14, 2017

Farmers in the Northeast are adapting to longer growing seasons and warming climate conditions - but they may face spring-planting whiplash as they confront fields increasingly saturated with rain, according to a research ...

Do vitamin supplements prevent macular degeneration?

October 31, 2017

Vitamin and mineral supplements won't prevent the development of age-related macular degeneration. But there is some evidence taking supplements containing vitamin C, vitamin E and zinc may slow the progression of age-related ...

Recommended for you

Three 'super-Earths' orbiting a cool dwarf star discovered

January 23, 2018

Using NASA's prolonged Kepler mission, known as K2, astronomers have found three new "super-Earth" exoplanets. The newly detected alien worlds orbit the cool dwarf star designated LP415-17. The finding is reported January ...

Toxin in centipede venom identified

January 23, 2018

A team of researchers from several institutions in China has identified the toxin in golden head centipede venom. In their paper published in Proceedings of the National Academy of Sciences, the group describes how they found ...

Optical nanoscope images quantum dots

January 23, 2018

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together ...

0 comments

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.