When South African botanist Lyall Watson claimed in his 1973 bestseller Supernature that plants had emotions and that these could register on a lie detector, scientists scoffed and branded it hippie nonsense.
But new research has revealed that plants appear to react to sounds and may even make clicking noises to communicate with each other. Scientists in Australia, Britain and Italy have collaborated to show that the roots of young plants emit and react to particular sounds.
The researchers established that young roots of corn made regular clicking sounds. They also found that young corn roots suspended in water leaned toward the source of a continuous sound emitted in the region of 220Hz, which is within the frequency range the same roots emitted themselves.
The findings, published in a paper "Towards Understanding Plant Bioacoustics" in the international journal Trends in Plant Science, concluded that the role of sound in plants had yet to be fully explored, “leaving serious gaps in our current understanding of the sensory and communicatory complexity of these organisms”.
In addition to other forms of sensory response, the researchers said it was very likely that some form of sensitivity to sound and vibrations also played an important role in the life of plants.
Postdoctoral research fellow Dr Monica Gagliano at the University of Western Australia conducted the research with colleagues Professor Daniel Robert at the University of Bristol and Professor Stefano Mancuso at the University of Florence to show that the roots of young plants emit and react to particular sounds.
“Everyone knows that plants react to light, and scientists also know that plants use volatile chemicals to communicate with each other, for instance, when danger, such as a herbivore, approaches,” Gagliano said.
“I was working one day in my herb garden and started to wonder if maybe plants were also sensitive to sounds; why not? So I decided as a scientist to find out.”
She hoped publication of the work would attract further funding for more research into how plants make and react to sounds.