Try to be quiet for a moment and listen to your surrounding environment, do you hear anything that might affect your emotion, like something beautiful or something annoying? Our hearing is one of the most useful gift we have, and our ability to response to what we hear is another.
Flowers have no ears whatsoever, which mean it is normal to assume that they cannot hear anything that happens around them. However, this assumption might have been proven false by researchers from Israel.
As published in bioRxiy, a group of researchers led by Lilach Hadany proved that even though plants don’t have any ear, but they can sense airborne sounds. What’s more amazing about this is, those plants can give ‘appropriate’ response to the sounds.
So, where do we go from here? In this article we are going to talk about this discovery, and how it might be able to help us in the future.
Hadany is an evolutionary theoretician at Tel Aviv University. Among other things, she chose to study how a species, of both plants and animals, can take advantages of resources in the nature to survive and pass on their genetic legacy.
Sounds belong to the most abundant and the most used natural resources in this planet, and we already know that many living organisms are using this resource to survive on earth. But the thing is, almost every single living organism that we know taking advantages of sounds are animals.
We still don’t know yet whether plants belong to those which take advantages of sounds as natural resource or not. In this case, Hadany thought that it would be such a waste if plants cannot take advantage of the abundant resource.
Thus, she decided to set up a test to find out whether plants completely neglect the presence of sound waves around their environment or not. She then tried to prove whether that theory true or false by using evening primroses (Oenothera drummondii).
By exposing the flower into the playback of buzzing bees, and some other sounds with almost similar frequency to buzzing bees, she tried to find out any changes happening in the flowers’ biology. Indeed, some amazing changes occurred.
Sugar, We’re Going Up
The playback of buzzing bees somehow tempted the flower to increase its sugar production in the nectar by up to 20%. “Our results document for the first time that plants can rapidly respond to pollinator sounds in an ecologically relevant way,” as stated in the study.
The finding reveals that in addition to being ‘passive-aggressive’ methods (such as using their appearance or constantly producing high level of sugar) to attract their pollinators, plants are able to lure their pollinators closer by being active in the process.
With more sugar they offer, pollinators such as bees will find it harder to resist the temptation. So, the only result available is an ‘arranged’ symbiotic mutualism between the flower that needs pollination and the pollinators that need food.
The next question is, why plants developed this kind of ability to attract insects? Hadany said that it might be the gift of long time evolution. “We have to take into account that flowers have evolved with pollinators for a very long time,” she said.
It might be the flowers’ way to cope with their environment in their stationary state. “They are living entities, and they, too, need to survive in the world. It’s important for them to be able to sense their environment, especially if they cannot go anywhere,” she explained.
But Why Do They Need ‘Ears’?
Flowers need pollinators to reproduce, and as they cannot move from their original place by themselves, they use baits to call the pollinators. Sweeter nectar attracts more insects, which means they get bigger chance to reproduce with the help of more pollinators.
Richard Karban, an expert in interactions between plants and their pests at the University of California Davis, agreed with the discovery that plants can hear. But Karban predicted that this ability is not only used when pollinators are near.
It might also be used to sense incoming dangers which may affect their survival, such as when pests are attacking neighboring plants. “It may be possible that plants are able to chemically sense their neighbors, and to evaluate whether or not other plants around them are fertilized,” Karban said.
But which part of the plant is the ‘ear’? The answer is their petals, which vibrate when sound waves at the frequency produced by pollinators. When pollinators pass by near the plants, the sound frequency from the wings is delivered to what researchers call as “the plant’s auditory sensory organ”.
Further studies are needed to completely understand about this topic, in which Hadany suggested a completely new field of study called phytoacoustics for us to study such kind of phenomenon. Hadany believes that there is still much more of this discovery that we need to learn about.
Can We Take Advantage Of It?
Here is the interesting part of this discovery. Knowing that plants can somehow sense incoming pollinators, and additionally may be able to sense incoming threats, it would benefit farmers (everyone in common, actually) all around the world.
In example, we can use the method of ‘playing their favorite songs’ to actually attract their ‘favorite bands’. As Hadany used pollinators’ recordings to check whether plants can give some responses to it, in which she succeeded, we can use it to eventually attract real bees coming.
Pollinators like bees are highly attracted with high-quality nectars, which in this case means sweeter nectars. Thus, as the nectars are sweeter after the plants are given the playback, there is higher chance that real bees will choose them among other flowering plants with lesser quality nectar.
Speaking about practicality, we may be able to play the sounds of buzzing bees in farmlands to increase the amount of sugar in nectar produced by plants. With more sugar content, surrounding pollinators will eventually come to them and do the job.
There are two possible benefits we can get if this method works. First, flowering plants in farmlands can reproduce easier because they simply attract more pollinators. Second, with higher quality nectar that the pollinators get from the plants, we might be able to give them more nutrition to again increase their population.