It may come as a surprise to many, but recent studies have shown that plants cry under stress. That’s right, folks, your potted plant may be more emotional than you think! Now, before you go wiping away your plant’s imaginary tears, it’s important to understand that plants don’t cry in the traditional sense.
But what exactly causes plants to get stressed out? Do they also go through similar kinds of exam stress like us or do they also face relationship tragedies or the societal pressure of getting a good degree, job, house, marriage, etc?
Well, just like humans, every other creature in this world has its struggles to be the fittest in the survival game and thus becomes anxious and strained during their journey.
So yes, plants also feel stressed out, but their stressors are unlikely to humans like drought, salinity, temperature variation, attack from the enemy, and physical damage.
Now, the question remains, do plants cry under stress? In a way, yes. When plants are under stress, they produce a hormone called jasmonic acid, which activates the production of volatile organic compounds (VOCs).
These VOCs are released into the air and can be detected by nearby plants and even insects. Some VOCs also have a scent, such as the aroma of freshly cut grass or the smell of flowers, which attracts pollinators.
So, plants can cry and sometimes you can observe this phenomenon through physical appearance as described above.
But can we listen to them cry? Previously it was impossible but now the advancements and integration of machine learning with biology make it possible.
Recently, researchers from Tel-Aviv University in Israel (Lilach Hadany and her colleagues) made the discovery that plants cry and we can listen to them.
An experiment was performed with tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum). They were put in boxes with microphones. After the study it was concluded that plants facing drought stress (shortage of water) produce roughly 35 sounds per hour. While the healthier stress-free plants were much calmer and the quitter in producing such sounds.
Now another question here arises. If plants make sounds so why do we never hear their cry and pledge for help?
Don’t worry, you are not at fault here. The reason for us not being able to hear them is that plants have a different cry language than us. They make noise in ultrasonic sound and are not like a kid whining. But if their sounds are pitched down and sped up, “it is a bit like popcorn — very short clicks”.
The ultrasonic sounds produced during a stressed environment range from about 20–100 kilohertz.
That means they are so high-pitched that few humans could hear them. Some animals, however, probably can.
Bats, mice, and moths could potentially live in a world filled with the sounds of plants, and previous work by the same team has found that plants respond to sounds made by animals, too.
So be mindful next time when you bring plants for your indoor or outdoor decoration or you plant some flowers in your garden. Keep this in mind when plucking them, cutting them out of joy, or putting them in any kind of stressful environment will make your lovely plants cry.
A research enthusiast striving to bring change in the field of Molecular Biology through my knowledge and skills for the betterment of humanity in general and for my home country Pakistan in particular.