Do you mean rapid exchange by non-chemical signals or slow allelopathic (chemical) via soil or faster via volatiles interaction? It is benefitial to one plant usually, but sometimes one plant have benefits from another with volatiles protecting from colonization by pests or pathogens.

Dear Joachim,

thanks for your scientific answer, but i want to know about plant-plant communication not Indirect defense or Priming. Is there any recent (2011-2014) experiment about plant-plant communication in natural conditions?

thank you.

Dear Alex,

Plants use their volatiles for long-distance systemic signaling and perception of these volatiles by neighbors is a side effect of this process, it is not a communication (i think so). I want to know is there any other types of "real" communication between plants?

Please, read Long-Distance Systemic Signaling and Communication in Plants

by František Baluška. http://books.google.ru/books?id=7VZEAAAAQBAJ&pg=PA319&lpg=PA319&dq=electromagnetic+signaling+between+plants&source=bl&ots=VnEbpXHWxA&sig=ljSj2u1pPdyvEEvgASGwa9XftbY&hl=en&sa=X&ei=IJTZUoXTJoHw4QTbp4C4AQ&redir_esc=y#v=onepage&q=electromagnetic%20signaling%20between%20plants&f=false

Plant-plant Communications may be possible either by physical means like radiation, which is still unexplored for plants or by chemical means. As you said the chemical volatiles are responsible for signalling. Herbivores and pathogens induce the genes for the production of these volatiles, which warn other plants about the threat and induce the expression of defense genes.

It depends how you define "real" communication. Usually, it's defined as an exchange of information where both sender and receiver role has evolved - see http://sites.sinauer.com/animalcommunication2e/chapter01.02.html for a review.

I think it's unrealistic to claim that plants haven't also evolved to exploit this "side effect" of long-distance systemic signaling, just because it sounds too mundane.

Dear Muhammad,

"Leaf shading response" is a acceptable communication between two plants, so there is radiation communication between plants.

Dear Jernej,

"Plant communication" defines as situations where cues that are emitted from plants cause rapid response in a receiver organism, and where the emission of these cues is plastic and conditional (Karban R (2008) Plant behaviour and communication . Ecol Lett 11 : 727 – 739).

Please read 'Airborne Induction and Priming of Defense" by Martin Heil , for more information about why plant-plant communication by volatiles is unreal and only a side effect.

Howdy Mohammad,

Sure plants do communicate plant to plant. The pigment which allows plants to communicate between each other as well as to observe the environment is called phytochrome and has a chemical structure somewhat analogous to the pigments responsible for vision by the human eye.

Plants can distinguish the radiation levels of red and far-red light and establish a photoequilibrium according to the ratio of red over far-red light.

Is that benificial, let's say for a tree? For sure it is, otherwise evolution would have let it disapear into oblivion.

What happens for example with the red-far-red ratio in a forest? Well red light is absorbed much more by chlorophyll when penetrating the forest canopy from top to bottom than far-red. That changes the ratio of red over far-red and hence the photostationnary equilibrium of phytochrome. A tree will respond to that by increasing its growth rate. Whu should he do that you say? When a plant experiences shadowing by a fellow tree it will experience a decrease in photosyntrhesis and that is not really benificial for its energy supply. Hence it will start growing faster. This is vital in a forest. If a tree would not adapt its growth speed to that of its neighbours, it would simply die sooner or later, due to a lack of light. Once a tree drops below the compensation point, it is done for.

A (natural) forest is actually a harsh ecosystem where trees compete for light. Therefore they have to sense whether they are shadowed or not by a neighbour tree and to what extent. They will, when shadowed, increase growth rate by sensing the red-far red ratio.

If that is not communication with a respons to the acquired information, then what about the information gathered by the human eye? What do we really do with it? Ok read the newspaper, look at your PC screen, etcetera.

But remember, a beautifull woman can make a blind man see, and that's the big difference between plant and human visual communication ;-)

Cheers,

Frank

Dear Irfanian,

Plants cross talk through volatile chemical signallings. Plants under attacks of herbivores sequesters certain specific blends of volatile chemicals and induce healthy neighbouring plants to produce herbivore repelling defensive chemicals and attacked one on the other hand also produce herbivore repelling chemicals. The insect attacked plants also signals to predators of herbivore or a pathogen. Thus, this defensive chemical signalling is often termed as 'cross talk'. There are many research paperson this theme, you may follow them.

Dear Frank Veroustraete

Good day

Thank you for the introduction of this new kind of signalling mechanism. As for as the chemical signalling is concerned a lot of work is being done these days. especially phyto-oxylipin pathway is being explored in connection with this sort of communication. The GLVs seem to be quite strong candidates involved in plant-plant communication.

An interesting answer I can tell you about is ISR. Methyl jasmonate (MeJA) produced in response to pathogens is a volatile compound can be a signal, alerting neighbors plant.

I think mycorrhiza can also provide a network between inoculated plants. it is in touch rout: should be more care about in future researches. You can think of it.

as we mentioned above, plant-plant communication through chemicals like GLVs, and anything else is just a side effect of Plant systemic signaling, plants do not release volatiles to inform their neighbors, volatiles are used for fast and strong response to herbivores and pathogens,

i think the only acceptable plant-plant communication (till now) is "leaf shading response", as Frank mentioned.

There is also root-to-root communication by soluble chemicals. For an introduction, please, check out http://www.the-scientist.com/?articles.view/articleNo/38727/title/Plant-Talk/

Plant-plant interactions can happen simply by their attachment on one another, such as how epiphytes like orchids or moss grow on other plants for support. A specific instance of interaction can be seen in the Monotropa uniflora, which can obtain nutrients indirectly from plants by mycorrhizal bridges they form with a host. Parasitism among plants can also be considered a direct interaction. This information, and more can be seen here: http://www.plantphysiol.org/content/116/1/1.full