If you cast your mind back to the days of those high school biology classes, can you remember anything you learned about plants? Maybe you remember a little bit about photosynthesis. But it’s quite probable that it’s not the most interesting or exciting memory in your life (unless you’re a botanist).
It has long been the struggle of plant scientists to express how amazing the subjects of their studies are – the truth is that plants are just underappreciated. But Monica Gagliano, a researcher at the University of Sydney, has made great strides in proving that plants can learn, just as animals and humans are able to.
Why plants are amazing anyway
Before Gagliano’s experiments, there were still a number of reasons to consider plants as awesome living beings. In terms of theories of evolution, they were present before animal life, and likely to be present long after it is gone. This is probably due to their ability to self-sustaining- better than other kinds of living creatures. Think about if you were left in an area with nothing but soil and water: you wouldn’t last very long, but a plant would. Some don’t even need that much water to survive and can grow on rocks. The vast majority of plants are even able to recycle their own oxygen and carbon dioxide, an ability most creatures are sorely lacking.
Lessons from Mimosa pudica
Above and beyond the above-mentioned capabilities, M. pudica, commonly known as the shameplant (how rude…) was able to demonstrate the ability to learn and remember. Gagliano dropped her plants about a foot, too little distance to do any damage. The plant curled its leaves, already showing a stress response, for a few drops, but eventually stopped. This led Gagliano to believe that the plant realized it wasn’t in danger and no longer had to stress when it fell. When she repeated this a month later, the same plants showed no stress response – demonstrating that these plants even had the ability to retain memory.
The intelligent pea plant
Another member of the pea plant family, Pisum sativum, showed a remarkable conditioning response similar to that of Pavlov’s dogs. Gagliano pointed a fan in the particular direction of light, which plants usually grow toward. P. sativum did exactly that, but what was amazing was that they continued to grow in that direction when only the fan was blowing and no light was present. Essentially, these plants had learned that the airflow of the fan showed them where the light was.
How do they do it?
As far as we know, plants don’t have a brain. However, Gagliano says that plants “do possess a sophisticated calcium-based signaling network in their cells similar to animals’ memory processes”. Calcium plays an important part in the electrical signals sent between brain cells, controlling sleep, and having a role in epilepsy. So, we may be more similar to our plant brothers and sisters than we previously thought.
So what does this mean?
Well, it opens up a whole debate about whether plants are actually sentient beings or not. What would happen to our world as we know it if we eventually prove that plants are self-aware and able to think in ways we never understood before? At this point, it’s a philosophical debate, but the time could come soon where it has real-world implications.