Scientists are studying and confirming how plants may actually have the ability to sense sounds, like flowing water in a pipe ― or even buzzing insects.
What? Plants hear sounds? That’s an earful. But not to researchers at the University of Western Australia, whose experiments point to the possibility that some plants may actually detect sound waves.
Evolutionary biologist Monica Gagliano and her colleagues worked with pea seedlings, which they inserted into pots that looked like an upside-down “Y.”
According to Scientific American:
One arm of each pot was placed in either a tray of water or a coiled plastic tube through which water flowed; the other arm had only soil. The roots grew toward the arm of the pipe with the fluid, regardless of whether it was easily accessible or hidden inside the tubing.
“They just knew the water was there, even if the only thing to detect was the sound of it flowing inside the pipe,” Gagliano says.
She suggests that the plants can use sound waves to identify water from a distance.
In the following University of Western Australia video, Gagliano further explains their research.
Gagliano’s investigations are reported in the May 2017 issue of Oecologia, an international peer-reviewed English-language journal. In the paper, titled “Tuned in: plant roots use sound to locate water,” Gagliano writes:
Because water is essential to life, organisms have evolved a wide range of strategies to cope with water limitations, including actively searching for their preferred moisture levels to avoid dehydration.
Plants use moisture gradients to direct their roots through the soil once a water source is detected, but how they first detect the source is unknown. We found that roots were able to locate a water source by sensing the vibrations generated by water moving inside pipes, even in the absence of substrate moisture.
Our results also showed that the presence of noise affected the abilities of roots to perceive and respond correctly to the surrounding soundscape.
Plants may even reflect animal sounds to communicate with them. So says University of Greifswald biologist Michael Schoner in Germany. In the August 2016 edition of ScienceDirect, a peer-reviewed collection of articles from nearly 4,000 journals, Schoner wrote:
Acoustic communication is widespread and well-studied in animals but has been neglected in other organisms, such as plants. However, there is growing evidence for acoustic communication in plant-animal interactions. Understanding the proximate mechanisms and ultimate causes of acoustic communication will shed light on an underestimated dimension of information transfer between plants and animals.
And still another reason for science to consider that plants hear is something called “buzz pollination,” in which bees buzzing at a specific frequency are able to stimulate the release of plant pollen, reports Scientific American. “Other experiments have found that sounds can lead to hormonal changes in plants, influence their oxygen uptake and change their growth rates,” according to the outlet.