Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists identify genes responsible for ’black rot’ disease in vegetables

17.05.2005


Large-scale comparative and functional genomics study characterizes bacterial pathogen responsible for major vegetable crop losses worldwide

Scientists at four major genomics and plant pathology laboratories in China have collaborated on a project to characterize the causative agent of "black rot" disease, which is the most serious disease of vegetable crops worldwide. Their study, which represents the largest comparative and functional genomics screen for a plant or animal bacterial pathogen to date, is published online today in the journal Genome Research.

"Black rot" is caused by the pathogenic bacterium Xanthomonas campestris pathovar campestris (or Xcc). Under favorable conditions (high humidity and temperature), Xcc infects vegetable crops by spreading through the plants’ vascular tissues, turning the veins in their leaves yellow and black, and causing V-shaped lesions along the margins of the leaves. All vegetables in the crucifer family, including broccoli, Brussels sprouts, cabbage, cauliflower, kale, mustard, radish, rutabaga, and turnip, are potential hosts for Xcc. The model plant Arabidopsis thaliana is also susceptible to Xcc infection. Surprisingly, however, some wild cruciferous weed species do not manifest the characteristic symptoms of "black rot" disease when infected.



To date, there is no effective treatment for Xcc infection, so in hopes of developing a treatment, scientists at four Chinese institutions (the Institute of Microbiology at the Chinese Academy of Sciences, the Chinese National Human Genome Center at Shanghai, Guangxi University, and the Chinese National Human Genome Center at Beijing) have focused their efforts on characterizing the genes responsible for Xcc pathogenicity. In their study published today, the investigators describe the identification of 75 different genes responsible for Xcc virulence. These genes appear to belong to 13 different functional categories or related metabolic pathways. The researchers hope that the molecular characterization of these pathogenicity-related genes will lead to the development of a treatment for "black rot" disease.

Employing whole-genome comparative genomic approaches, the authors sequenced the complete genome of an Xcc strain that was isolated from an infected cauliflower plant in England during the 1950’s. They then compared this sequence to a previously published sequence from a cabbage-derived Xcc strain. Although the gene content of the two strains was very similar, the authors identified several genes located on strain-specific chromosomal elements that were unique to each strain. In addition, there were dramatic differences in the genomic arrangement of the two strains; the scientists identified significant rearrangements between the genomes, including major translocations, inversions, insertions, and deletions.

In order to functionally characterize Xcc and identify genes implicated in its pathogenicity, the researchers then screened an Xcc transposon insertional mutant library in its host plant (cabbage). They screened a total of 16,512 Xcc mutants on individual cabbage plants and, of these, 172 proved to be non-pathogenic. Upon further characterization of the 172 non-pathogenic mutants, the researchers came up with a non-redundant list of 75 genes or non-coding regions that are involved in Xcc pathogenicity.

Interestingly, the researchers identified three genes that were implicated in pathogenicity but that were not present in the previously described Xcc genomic sequence. To test the biological implications of this observation, they inoculated five different vegetable species with the three mutants corresponding to these strain-specific genes, and they observed significant differences in the response of each host species to infection. The authors point out that these findings highlight the role of genome dynamics in the evolution of pathogenicity in Xcc in response to different host species.

Maria A. Smit | EurekAlert!
Further information:
http://www.cshl.edu

More articles from Life Sciences:

nachricht Another piece of Ebola virus puzzle identified
17.01.2019 | Texas Biomedical Research Institute

nachricht New scale for electronegativity rewrites the chemistry textbook
17.01.2019 | Chalmers University of Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Ultra ultrasound to transform new tech

World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles

The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

Im Focus: Mission completed – EU partners successfully test new technologies for space robots in Morocco

Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.

Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

A new twist on a mesmerizing story

17.01.2019 | Physics and Astronomy

Brilliant glow of paint-on semiconductors comes from ornate quantum physics

17.01.2019 | Materials Sciences

Drones shown to make traffic crash site assessments safer, faster and more accurate

17.01.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>