How Smart Are Plants?

It doesn’t have a brain, but the Venus fly trap
can still use short-term memory.

http://blogs.discovermagazine.com/80beats/2012/06/06/how-smart-are-plants/

We tend to treat plants like passive objects that can ornament a home or yard, although perhaps requiring a bit more care than, say, a vase. But plants are in fact complex organisms that can interact with their environment, sense smells and sounds,communicate with each other and with insects, and even process information.

To see how plants’ abilities stack up in comparison with human sensing and thinking, Scientific American interviewed Daniel Chamovitz, a plant biologist and author of What a Plant Knows. In addition to plants’ unexpected abilities, Chamovitz shares that they have some downright improbable skills, skills that tend to require a brain—skills like memory.

Plants definitely have several different forms of memory, just like people do. They have short term memory, immune memory and even transgenerational memory! I know this is a hard concept to grasp for some people, but if memory entails forming the memory (encoding information), retaining the memory (storing information), and recalling the memory (retrieving information), then plants definitely remember. For example a Venus Fly Trap needs to have two of the hairs on its leaves touched by a bug in order to shut, so it remembers that the first one has been touched. But this only lasts about 20 seconds, and then it forgets. Wheat seedlings remember that they’ve gone through winter before they start to flower and make seeds. And some stressed plants give rise to progeny that are more resistant to the same stress, a type of transgenerational memory that’s also been recently shown also in animals. While the short term memory in the venus fly trap is electricity-based, much like neural activity, the longer term memories are based in epigenetics — changes in gene activity that don’t require alterations in the DNA code, as mutations do, which are still passed down from parent to offspring.

Although plants may be able to process information, Chamomvitz rejects the idea that there could be a field of neurobiology, or “neuroscience of plants, minus the neurons.” He does, however, point out that plants produce some of the same chemicals that play an important role in the human brain. Perhaps, Chamovitz jokes, “There could be a botany of humans, minus the flowers.”