Navigation Links
Plant defenses prompt bacterial countermeasure in the form of 'island' DNA excision

Seeking to catch an arms-race maneuver in action, researchers have uncovered new evidence to explain how bacteria in the process of infecting a plant can shift molecular gears by excising specific genes from its genome to overcome the host plant's specific defenses.

Throughout evolution ?in the wild and in crops cultivated by humans ?plants have developed systems for resisting the attack of microbial pathogens, while these microbes themselves have depended on their ability to alter molecular attack strategies in order to flourish. In the new work, researchers have essentially caught one step of this arms race in action, and they have shed light on the molecular mechanisms employed by a bacterial pathogen to survive in the face of its host plant's defenses. The research is reported by John Mansfield and colleagues at Imperial College London, the University of the West of England, and the University of Bath.

Studying interactions between strains of the halo-bright pathogen and bean plants, the researchers found that the pathogenic bacteria essentially kicks out a section of its genome when it senses that its presence has been detected by the plant's defense system. Excising this so-called "genomic island" eliminates production of the bacterial protein detected by the plant and allows a more stealthy ?and successful ?invasion.

The reason the strategy can be successful is that the plant has evolved to recognize the presence of only certain bacterial proteins as warnings of an infection. This means that the bacteria can, in principle, evade detection if it can shut down production of the offending protein or proteins. In their study, the authors identify within the halo-bright pathogen genome a special island of DNA that encodes one such offending protein. But this genomic island also encodes enzymes that, when switched on, snip the DNA on either side of the island, resulting in the excision of the entire island from the genome. The researchers fou nd that this excision occurs in response to a so-called hypersensitive resistance reaction by the plant . The specific plant signals that are sensed by the pathogen to trigger the excision event remain to be identified.

If some bacterial proteins give away the presence of the pathogen to the plant, why are they and their surrounding genomic islands maintained by the bacteria at all? There are many genes included in the genomic island that is excised by the halo-bright strains studied here, and these other genes may well encode proteins that allow the pathogen to survive optimally in the light-intensive regions of eastern and southern Africa where these strains are found. Remarkably, bacteria that have excised the genomic island do not appear compromised in their ability to grow and cause disease within the host bean plant.

These findings offer a molecular explanation for how exposure to plant resistance mechanisms can directly drive the evolution of new virulent forms of a bacterial pathogen.


'"/>

Source:Cell Press


Related biology news :

1. Quantum Dots Research Leads to New Knowledge about Protein Binding in Plants
2. Plants, animals share molecular growth mechanisms
3. Plants respond similarly to signals from friends, enemies
4. Affymetrix Unveils Plans to Double Plant and Animal Genome Microarray Offering
5. Plant hemoglobins: Oxygen handlers critical for nitrogen fixation
6. Plants defy Mendels inheritance laws, may prompt textbook changes
7. Whats really making you sick? Plant pathologists offer the science behind Sick Building Syndrome
8. Plant Sacrifices Cells to Fight Invaders
9. Breakthrough System for Understanding Ocean Plant Life Announced
10. Plant pathologists evaluate eco-friendly alternatives to methyl bromide
11. Study: Plants use dual defense system to fight pathogens
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/19/2016)... 2016 The new GEZE SecuLogic ... web-based "all-in-one" system solution for all door components. It ... the door interface with integration authorization management system, and ... The minimal dimensions of the access control and the ... installations offer considerable freedom of design with regard to ...
(Date:4/14/2016)... TEL AVIV, Israel , April 14, 2016 /PRNewswire/ ... in Behavioral Authentication and Malware Detection, today announced the ... has already assumed the new role. Goldwerger,s ... for BioCatch, on the heels of the deployment of ... In addition, BioCatch,s behavioral biometric technology, which discerns unique ...
(Date:3/31/2016)... , March 31, 2016  Genomics firm Nabsys has ... CEO, Barrett Bready , M.D., who returned to ... the original technical leadership team, including Chief Technology Officer, ... Product Development, Steve Nurnberg and Vice President of Software ... the company. Dr. Bready served as CEO ...
Breaking Biology News(10 mins):
(Date:5/26/2016)... 2016 Despite the volatility that continues ... space. Today,s pre-market research on ActiveWallSt.com directs the investor community,s ... RDUS ), Cerus Corp. (NASDAQ: CERS ... Five Prime Therapeutics Inc. (NASDAQ: FPRX ). Register ... http://www.activewallst.com/ On Wednesday, shares in ...
(Date:5/26/2016)... , ... May 26, 2016 , ... ... FireflySci cuvettes are used in leading laboratories all over the globe. Their cute ... In addition to manufacturing awesome cuvettes, FireflySci makes spectrophotometer calibration standards that never ...
(Date:5/25/2016)... ... May 25, 2016 , ... The Ankle Plating ... options designed to address fractures of the distal tibia and fibula. This system ... Ankle Plating System 3 is composed of seven plate families that span the ...
(Date:5/25/2016)... ... ... Scientists at the University of Athens say they have evidence that the variety ... that could lead to one good one. Surviving Mesothelioma has just posted an article ... team evaluated 98 mesothelioma patients who got a second kind of drug ...
Breaking Biology Technology: