Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacteria Use Plant Defence for Genetic Modification

19.10.2007
Bacteria that cause tumours in plants modify plant genomes by skilfully exploiting the plants' first line of defence. Utilising the plant's own proteins, bacterial genes infiltrate first the nucleus then the plant genome, where they reprogramme the plant's metabolism to suit their own needs. This process was recently discovered as part of an Austrian Science Fund FWF project and was published today in SCIENCE.

The genetic manipulation of plants is both, a subject of great controversy in Europe and a tactic already practiced by certain bacteria. The soil bacterium known as crown-gall bacterium (Agrobacterium) manipulates the genetic make-up of plants by inserting its own DNA into the nuclei and, consequently, into the genetic material of the plant cells. The genetically modified plants are then reprogrammed to ensure uninhibited cell division and produce nutrients to feed the bacteria. What was not previously understood is exactly how bacteria genes infiltrate the cell's nucleus – particularly as the defence mechanisms of plant cells react so rapidly to bacterial invasion.

WEAK DEFENCES
A surprising detail of this process has now been uncovered by the team of Prof. Heribert Hirt working at the Max F. Perutz Laboratories at the University of Vienna and the URGV Plant Genomics Institute near Paris which Hirt joined as future director earlier this year. VIP1, a plant cell protein, is at the heart of their research. It was already known that this protein supports the transport of bacterial DNA known as T-DNA into the nucleus, and yet the exact role of VIP1 was unclear. Prof. Hirt explains: "We were able to show that VIP1 is a protein that regulates various genes designed to defend against bacterial invasion. However, VIP1 only occurs initially in the cytoplasm of cells and – in order to fulfil its role as a regulator – it then needs to migrate into the nucleus. It is precisely this movement that the bacterium exploits in order to inject its T-DNA into the nucleus." Prof. Hirt compares this strategy, which inevitably means that the plants own defences cause its downfall, to the famous Trojan Horse.
FRIEND & FOE
Prof. Hirt explains further – "Plants have an immune defence mechanism that is triggered when the plant detects certain molecules of the invader and works by activating genes in the nucleus." Once the invader has been detected, specific protein kinases in the cytoplasm are activated. These are enzymes that regulate the activity of other proteins by adding phosphate groups to them. One of the proteins phosphorylated by these protein kinases is VIP1, which is only granted access to the nucleus after this phosphorylation, so that it can activate the relevant defence genes there.

The following model illustrates the early processes in an infected plant cell. The invasion of T-DNA and the identification of the bacterium as an invader occur simultaneously. While protein kinases phosphorylate VIP1 in the cytoplasm, the bacterial T-DNA adheres to VIP1, thereby enabling it to infiltrate the nucleus unnoticed. The result is the joint infiltration of both friend and foe. Once inside the nucleus, the T-DNA is inserted into the plant genome and the process of tumour formation begins while the activated defence genes simultaneously organise the plant cell's defence mechanisms. It is too late though – the cell has already been transformed.

Till C. Jelitto | alfa
Further information:
http://www.fwf.ac.at/en/public_relations/press/pv200710-2en.html

Further reports about: Nucleus T-DNA VIP1 bacterium genes

More articles from Life Sciences:

nachricht The body's street sweepers
18.12.2017 | Ludwig-Maximilians-Universität München

nachricht Life on the edge prepares plants for climate change
18.12.2017 | Max-Planck-Institut für Entwicklungsbiologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Error-free into the Quantum Computer Age

A study carried out by an international team of researchers and published in the journal Physical Review X shows that ion-trap technologies available today are suitable for building large-scale quantum computers. The scientists introduce trapped-ion quantum error correction protocols that detect and correct processing errors.

In order to reach their full potential, today’s quantum computer prototypes have to meet specific criteria: First, they have to be made bigger, which means...

Im Focus: Search for planets with Carmenes successful

German and Spanish researchers plan, build and use modern spectrograph

Since 2016, German and Spanish researchers, among them scientists from the University of Göttingen, have been hunting for exoplanets with the “Carmenes”...

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

The body's street sweepers

18.12.2017 | Life Sciences

Fast flowing heat in layered material heterostructures

18.12.2017 | Materials Sciences

Life on the edge prepares plants for climate change

18.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>