Plants are ‘listening’!
A news release from the University of Western Australia announced that “plants have far more complex and developed senses than we thought” with the ability to detect and respond to sounds.1 In particular, fascinating research has shown that seedling roots can ‘hear’ the sound of gurgling water.
Researchers grew pea seedlings in pots shaped like an upside-down Y, such that roots had a two-way ‘choice’.2 E.g. they grew towards wet soil rather than dry soil, or aimed for a tray of water instead of the dry soil. Remarkably, when one of the choices was a sealed pipe through which water flowed, seedling roots grew towards it rather than dry soil.
“They just knew the water was there, even if the only thing to detect was the sound of it flowing inside the pipe,” explained lead researcher Monica Gagliano.3 And in the instance of wet soil being offered as an alternative, the plant roots grew towards it rather than the gurgling pipe, prompting the researchers to surmise that plants use sound waves to detect water at a distance, but home in on actual moisture when it is nearer.
Dr Gagliano explained the research “indicates that the invasion of sewer pipes by tree roots may be based on the plants ‘hearing’ water and shows that their perception of their surroundings is much greater and far more complex than we previously thought.”1
Actually, Gagliano herself has been on the trail of plant sensory capability for some time, although she is also a marine biologist and a musician. She had earlier discovered that corn roots distinctly bend towards the source of continuous sound (especially at frequencies of 200–300 Hz).4 Other researchers, too, have been spurred on to investigate “the plant’s acoustical environment and what it might be listening for”5 (e.g. chomping caterpillars,5 and even other plants6).
Where did such impressive ‘hearing’ ability come from? According to Dr Gagliano and her co-workers, it is apparently attributable to evolution, as they have written for example that “Plants vibrate at the rhythm of an evolutionary common sense.”4 But the staggering complexity of plants, with these incredible sensory capacities only now being uncovered by scientists after years of painstaking research, speaks powerfully of having been designed—on Day 3 of Creation Week (Genesis 1:11–13). The Bible identifies this Designer as our Creator, Lord, and Saviour, Jesus (Colossians 1:16).
References and notes
- Study reveals plants ‘listen’ to find sources of water, news.uwa.edu.au, 11 April 2017. Return to text.
- Gagliano, M., and 3 others, Tuned in: plant roots use sound to locate water, Oecologia 184(1):151–160, 2017 | doi:10.1007/s00442-017-3862-z. Return to text.
- Zaraska, M., Can plants hear? Scientific American 317(1):20, July 2017 | doi:10.1038/scientificamerican0717-20. Return to text.
- Gagliano, M., Mancuso, S., and Robert, D., Towards understanding plant bioacoustics, Trends Plant Sci. 17:323–325, 2012. Return to text.
- Meissen, R., Hearing danger: predator vibrations trigger plant chemical defenses, decodingscience.missouri.edu, 1 July 2014. Return to text.
- Gagliano, M., and 4 others, Out of sight but not out of mind: Alternative means of communication in plants. PLoS ONE 7(5):e37382, 2012 | doi: 10.1371/journal.pone.0037382. Return to text.