Careful they might hear you!
Tuesday, 18th April, 2017
THOSE of us who eyed our sad-looking palm in the corner of the room with trepidation after watching the movie The Day of the Triffids have yet another reason to suffer plant paranoia.
According to University of WA researchers, plants have far more complex and developed senses than we thought and may even be able to "hear" - remember the Triffids sound-locating by moving their "heads" from side to side?
A study found that plants have the ability to respond to the sound of water running through pipes and the soil, and will move their roots towards the source.
There are certain sounds they do not like, and they will move away from their source.
Lead researcher Monica Gagliano from UWA's Centre of Evolutionary Biology said water was a basic need for a plant's survival and the study showed that sound played a significant role in helping plants cater to this need.
"We used the common garden pea plant (Pisum satvium) as the model for our study and put the plant into a container which had two tubes at the base, giving it a choice of two directions for the growth of its roots," Dr Gagliano said.
"We then exposed the plant to a series of sounds, including white noise, running water and then a recording of running water under each tube, and observed its behaviour."
The scientists found the plants could tell where the water source was and their root systems grew towards that source based on sensing the sound of running water alone.
"It also was surprising and extraordinary to see that the plant could actually tell when the sound of running water was a recording and when it was real - and the plant did not like the recorded sound."
Dr Gagliano said when moisture was readily available in the soil and the plant did not need water, the plant did not respond to the sound of running water.
"From this we begin to see the complexity of plant interactions with sound in using it to make behavioural decisions.
"It indicates that the invasion of sewer pipes by tree roots may be based on the plants 'hearing' water and shows their perception of their surroundings is much greater and far more complex than we previously thought."