Flowers can hear buzzing bees—and it makes their nectar sweeter
“I’d like people to understand that hearing is not only for ears.”
PUBLISHED
Even on the quietest days, the world is full of sounds: birds chirping, wind rustling through trees, and insects humming about their business. The ears of both predator and prey are attuned to one another’s presence.
Sound is so elemental to life and survival that it prompted Tel Aviv University researcher Lilach Hadany to ask: What if it wasn’t just animals that could sense sound—what if plants could, too? The first experiments to test this hypothesis, published recently on the pre-print server bioRxiv, suggest that in at least one case, plants can hear, and it confers a real evolutionary advantage.
Hadany’s team looked at evening primroses (Oenothera drummondii) and found that within minutes of sensing vibrations from pollinators’ wings, the plants temporarily increased the concentration of sugar in their flowers’ nectar. In effect, the flowers themselves served as ears, picking up the specific frequencies of bees’ wings while tuning out irrelevant sounds like wind.
The sweetest sound
As an evolutionary theoretician, Hadany says her question was prompted by the realization that sounds are a ubiquitous natural resource—one that plants would be wasting if they didn’t take advantage of it as animals do. If plants had a way of hearing and responding to sound, she figured, it could help them survive and pass on their genetic legacy.
Since pollination is key to plant reproduction, her team started by investigating flowers. Evening primrose, which grows wild on the beaches and in parks around Tel Aviv, emerged as a good candidate, since it has a long bloom time and produces measurable quantities of nectar.
A brown and yellow hoverfly rests on a dewdrop-covered evening primrose in the U.K.
To test the primroses in the lab, Hadany’s team exposed plants to five sound treatments: silence, recordings of a honeybee from four inches away, and computer-generated sounds in low, intermediate, and high frequencies. Plants given the silent treatment—placed under vibration-blocking glass jars—had no significant increase in nectar sugar concentration. The same went for plants exposed to high-frequency (158 to 160 kilohertz) and intermediate-frequency (34 to 35 kilohertz) sounds.
But for plants exposed to playbacks of bee sounds (0.2 to 0.5 kilohertz) and similarly low-frequency sounds (0.05 to 1 kilohertz), the final analysis revealed an unmistakable response. Within three minutes of exposure to these recordings, sugar concentration in the plants increased from between 12 and 17 percent to 20 percent.
A sweeter treat for pollinators, their theory goes, may draw in more insects, potentially increasing the chances of successful cross-pollination. Indeed, in field observations, researchers found that pollinators were more than nine times more common around plants another pollinator had visited within the previous six minutes.
“We were quite surprised when we found out that it actually worked,” Hadany says. “But after repeating it in other situations, in different seasons, and with plants grown both indoors and outdoors, we feel very confident in the result.”
Flowers for ears
As the team thought about how sound works, via the transmission and interpretation of vibrations, the role of the flowers became even more intriguing. Though blossoms vary widely in shape and size, a good many are concave or bowl-shaped. This makes them perfect for receiving and amplifying sound waves, much like a satellite dish.
There have been many anecdotal reports of the beneficial effects on plant growth of talking/singing to one's plants, or playing music to plants. This study narrows down the particular beneficial frequencies of sound vibration wch plants are sensitive/responsive to.
ReplyDeleteThis study only focused on the flower parts of the plant ,and then only on the sugar content of the nectar of the flowers.. What is the response in the non-flower parts of the plant?
there is the question whether this response to sound energy occurs by upregulating photosynthesis within the whole plant ,or by a different metabolic pathway such as the conversion of starch to sugar within the flower's nectaries or the translocation of sugar from other parts.
Can playing this sound frequency be used to augment the accumulation of sugar in berries such as grapes?
The Secret Life of Trees
ReplyDeleteSuzanne Simard has spent a lifetime trying to understand the secret societies of trees — how they work together, help each other and even how they speak to one another. Simard is a professor of forest ecology at the University of British Columbia. She tells us about her work, what it means for old-growth forests amid a climate emergency and her new book Finding the Mother Tree.
https://www.cbc.ca/listen/live-radio/1-63-the-current/clip/15875890-suzanne-simard-secret-societies-trees?fbclid=IwAR0HdjuV6kJ4-6FAIhJ2wp-IzETdNf4k885kmQzErV_MqXOt1989PuQfzac
Aired: Nov. 2, 2021
cbcradio/the current. Finding the Mother Tree --Suzanne Simard
mycorhiza fungi form mutually beneficial relationship with plants mycorhizal networks connect plants into communities
How sentient are plants?
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HTTPS://WWW.CBC.CA/LISTEN/LIVE-RADIO/1-63-THE-CURRENT/CLIP/16059598-oes-bee-inner-life
ReplyDeletea new scientific declaration argues that bees, snakes and a broad array of animals experience consciousness. we talk to the declaration’s co-author kristin andrews about what that means, from our relationship with nature to what's for dinner.
https://www.facebook.com/share/r/2Fk9wYNFqFmhsVrg/?mibextid=oFDknk
ReplyDeleteAre plants smarter than we think?
ReplyDeletelisten/live-radio/1-57-the-sunday-magazine/clip/16066533-yes-plants-communicate-other.-heres-scientists-smarter-think