Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unraveling plant reactions to injury

30.05.2011
Identification of a key compound that regulates plant responses to wounding could provide benefits on three fronts

Better understanding of plant defense systems, and the potential to generate stress-tolerant plants and even new malaria drugs, may all stem from the documentation of a molecular mechanism that plays a significant role in the response of plants to physical injuries, such as cuts. A team of agricultural researchers in Japan, led by Fuminori Takahashi of the RIKEN Plant Science Center in Tsukuba, found that the key protein in the complex mechanism is MPK8, which is fully activated by two signaling pathways working in concert[1].

The researchers showed that MPK8 is activated while the wounded plant mounts an initial emergency response to an injury. Around the fresh wound, the plant produces reactive oxygen species (ROS), such as hydrogen peroxide. These highly toxic compounds kill any pathogens that could access internal tissues via the wound site. However, since ROS can also harm plant tissue they require close regulation. Takahashi and his team—from RIKEN and three Japanese universities—found that the regulator is MPK8.

In addition to the initial response, the injury stimulates the release of calcium ions and starts a cascade of phosphorylation or phosphate-adding compounds. The compounds involved are called mitogen-activated protein kinases (MAPKs). MPK8 is one of the MAPKs of the model plant Arabidopsis.

Takahashi and his colleagues used Arabidopsis plants to investigate how both signaling and the levels of ROS are regulated after physical injury. Using plants into which they had introduced additional copies of the MPK8 gene, the researchers showed that MPK8 was activated under stress, particularly from physical wounding. MPK8 was strongly activated by MKK3, another MAP kinase from higher up the cascade. But it was also activated by calcium ions, specifically when they were bound to proteins called calmodulins. In addition, the researchers determined that the production of MPK8 was associated with regulation of ROS, lowering its accumulation.

A region of MPK8 known as TDY is known to interact or be phosphorylated with both MKK3 and calcium-bound calmodulins. By inhibiting each of these compounds in turn, the researchers showed that full activation of MPK8 demanded activating both of them at once, bringing the signaling pathways together. Finally, by examining the expression of genes, they found that MPK8 regulates the production of ROS by repressing the gene that stimulates their production (Fig 1).

“We think our findings might eventually lead to designing a drug treatment for malaria infection,” says Takahashi, “because the Plasmodium parasite involved uses the same kind of MAPKs.”

The corresponding author for this highlight is based at the Gene Discovery Research Group, RIKEN Plant Science Center

Journal information

[1] Takahashi, F., Mizoguchi, T., Yoshida, R., Ichimura, K. & Shinozaki, K. Calmodulin-dependent activation of MAP kinase for ROS homeostasis in Arabidopsis. Molecular Cell 41, 649–660(2011).

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

Further reports about: Arabidopsis plant Arabidopsis thaliana MAP MAPKs MPK8 RIKEN calcium ions signaling pathway

More articles from Life Sciences:

nachricht Newly designed molecule binds nitrogen
23.02.2018 | Julius-Maximilians-Universität Würzburg

nachricht Atomic Design by Water
23.02.2018 | Max-Planck-Institut für Eisenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>