Research team discovers new kind of signalling mechanism in plant cells

Jun 25, 2013

Plants possess receptors which are similar to the glutamate receptors in the brain of humans and animals. Biochemists at the Ruhr-Universität Bochum (RUB) with colleagues from the University of Würzburg and the Agricultural University of China in Beijing have discovered that these receptors do not, however, recognise the amino acid glutamate, but many other different amino acids. The team reports in the journal Science Signaling.

Glutamate-like receptor in Arabidopsis recognises many amino acids

To exchange information, cells send out signalling molecules that are recognised by receptors of other cells. Fifteen years ago, researchers discovered glutamate-like receptors, in short GLRs, in a plant. A team led by the RUB biochemists Prof. Dr. Michael Hollmann and Dr. Daniel Tapken has now identified the respective signalling molecules for one of the, in total, 20 GLRs from the thale cress (Arabidopsis thaliana). "Surprisingly, the receptor responds not only to one amino acid, but to many different ones – just not to glutamate", says Hollmann. The most effective is methionine, an amino acid that humans have to obtain from food, but which plants can produce themselves. When the research team mutated the plant so that it no longer contained the receptor AtGLR1.4, it hardly responded to methionine.

Plant receptor is an ion channel

In some respects, the receptor AtGLR1.4 behaves in a way similar to the glutamate receptors in the brain. It is a channel, so it opens – activated by a signalling molecule – a and allows various positively charged particles to flow into the cell, thus triggering an electrical signal. "A special feature of this receptor is that not all amino acids that bind to it trigger an . On the contrary! Some suppress the signal by displacing methionine from the receptor", says Daniel Tapken.

Function of methionine receptors in plants unclear

"Why the plant recognises methionine and similar amino acids at all is still absolutely unclear", the Bochum biochemist goes on. "One possibility is that it reacts in this way to nutrient sources in the environment that contain amino acids. However, it is also possible that the plant deliberately produces itself to send signals – similar to the way it happens in the human brain."

Receptors expressed in frog egg cells for analysis

For the analyses, the RUB team isolated the glutamate-like receptor from plant cells and implemented it in a cell that has no similar receptors – an unfertilised frog egg cell. "It is almost impossible to examine the receptor directly in the plant", Hollmann explains. "There are so many processes operating at the same time that it is extremely difficult to filter out the critical signals."

Explore further: New study shows safer methods for stem cell culturing

More information: Tapken, D. et al. (2013): A plant homolog of animal glutamate receptors is an ion channel gated by multiple hydrophobic amino acids, Science Signaling. DOI: 10.1126/scisignal.2003762

Related Stories

Great mystery of a plant defence pathway unravelled

Jun 03, 2013

(Phys.org) —Together with several partners, scientists from Wageningen UR (University & Research centre) have discovered that RLP-receptors located at the outside of plant cells and playing an important ...

Researchers design variant of main painkiller receptor

Jun 14, 2013

Opioids, such as morphine, are still the most effective class of painkillers, but they come with unwanted side effects and can also be addictive and deadly at high doses. Designing new pain-killing drugs ...

Recommended for you

Malaria transmission linked to mosquitoes' sexual biology

4 hours ago

Sexual biology may be the key to uncovering why Anopheles mosquitoes are unique in their ability to transmit malaria to humans, according to researchers at Harvard T. H. Chan School of Public Health and University of Per ...

Intermediary neuron acts as synaptic cloaking device

5 hours ago

Neuroscientists believe that the connectome, a map of each and every connection between the millions of neurons in the brain, will provide a blueprint that will allow them to link brain anatomy to brain function. ...

Skeleton of cells controls cell multiplication

5 hours ago

A research team from Instituto Gulbenkian de Ciencia (IGC; Portugal), led by Florence Janody, in collaboration with Nicolas Tapon from London Research Institute (LRI; UK), discovered that the cell's skeleton ...

New study shows safer methods for stem cell culturing

Feb 25, 2015

A new study led by researchers at The Scripps Research Institute (TSRI) and the University of California (UC), San Diego School of Medicine shows that certain stem cell culture methods are associated with increased DNA mutations. ...

User comments : 0

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.