07 February 2012

"Run, forest, run!"

A post at the BBC's Science and Environment includes a video from a new BBC Two series entitled "How To Grow A Planet."
For the first time, scientists at Exeter University have captured on film the process by which plants alert each other to possible dangers. When a plant is under attack it releases a gas which warns neighbouring plants to protect themselves. 
The ability of plants to communicate with one another isn't new; the novelty is that this has now been "captured on film."  It's doesn't seem likely that the flashes shown on the video are "real" -  perhaps they are CGI representations of more subtle changes.  The flashes (beginning at 1:30) are said to be evidence of "biological activity."  One suggestion at the Reddit thread: "my guess is that these are transgenic plants containing a foreign gene known as a "reporter" that produces a visual signal of some kind in response to the gas they are interested in. This signal could be light, but it is probably very, very dim."

And I wonder what gas the plants are releasing that serves as the messenger?

(I can't embed the video; those interested will need to view it at the link.)

And a hat tip to 127001y in the Reddit thread for suggesting the phrase I used for the title.


  1. Does this make vegetarians that don't eat meat for moral reasons bigoted hypocrites?

  2. The suggestion at Reddit is correct. The plants are expressing luciferase, which emits a faint light in response to the gas communication. The signal was detected and enhanced for the video.

    c.f. http://www.exeter.ac.uk/research/news/title_178237_en.html

    1. Thanks, anon. And from the link, this statement -

      The scientists know that a mix of chemicals is being emitted by the wounded plants, but they don’t know which the active ingredient is...

      - which suggests that the term "gas" used in the reports may not refer to a physical gas.

    2. Not sure what you mean by 'physical gas', but it's obviously a gas. It's not a liquid or solid. Air is a gas with many ingredients. These ingredients change all the time.

      When you smell a tasty soup, you are clearly smelling a gas. But what is the active ingredient that makes the good smell? You don't know.

      Same as with the plants. They're going to have to analyze changes in the air surrounding wounded plants, isolate or synthesize certain volatile (gaseous) components, and see if they alone trigger changes in other plants.

    3. One alternative example would be pheromones, which are chemicals that travel through the air as a form of communication (insects, mammals), but are not gases.

      (Maybe this is a matter of semantics rather than science per se).

    4. The things emitted by the plants ARE pheromones. Volatile pheromones (which are what people tend to think of when they think of pheromones) are gases.

      You're probably just confused because when people talk about pheromones, they are usually talking only about a subset of animal pheromones. And in school we hear mostly about elemental gases.

      -Chuck (by the way, though I assume you already knew this from my IP address)

    5. I didn't know those things. Thanks.

      And I don't know how to look up IP addresses. (?)

  3. This is the type of information that I love learning at this blog. Awesome!

  4. I, too, emit more gas when stressed...

  5. Yes, the technique is called in vivo biophotonic imaging and it relies on luciferase.

    Luciferases are enzymes naturally present in numerous species serving as a signal emitter to attract prey, startle predators or as a mean to find a mate. In biomedical research this interesting and useful feature of luciferase has been exploited since the 1980s, and luciferase cloned from the American firefly (Photinus pyralis) has become one of the most popular reporter genes for gene promoter studies (deWet et al.,1985). The light production is made possible by adding the substrate luciferin to the cells, and importantly the signal to noise ratio is extremely high.

    In 1995, Christopher Contag and his group discovered that the light produced by the luciferase enzyme is sufficiently intense to be detected externally when placed inside a rat or a mouse using a sensitive camera. This discovery thus made possible non-invasive imaging of a variety of interesting biological problems such as the spread and treatment of bacterial infection using bacterial luciferase, tracing of cancer cells tagged with luciferase and to study gene regulation in genetically modified mice (Contag et al., 1998).


Related Posts Plugin for WordPress, Blogger...