The question of plant consciousness has been around for a long time because people tend to attribute to plants, trees, rocks, and other physical phenomena the same feelings that humans have. It is more like a desire for people to expand their consciousness. We don't have enough of our consciousness, so we try to include many other things, other living beings, and also physical phenomena in our consciousness. We want to have a wider impact on this world with our consciousness.
Unfortunately, scientists themselves are also misled on this issue, as they are fascinated by the use of analogies in plant biology, which are often metaphors. There is a well-known strand of plant researchers who say that they represent plant neurobiology, which is an absolute metaphor because we understand that plants do not have a nervous system and do not have a brain that could provide them with this kind of response.
Opponents of these views will be amused to learn that the biology of human flowering could just as easily be discussed as the neurobiology of plants. We often confuse the ability of plants to adapt to their environment with their ability to consciously respond to these environmental changes. All living organisms are capable of perceiving environmental signals, from protozoa to humans, but the level of perception varies considerably. There is reactive behavior, which plants have, and proactive behavior, which is much more nuanced.
Reactive behavior is when all of an organism's actions are subordinated to the signal and follow the signal. Plants cannot do anything in the absence of this signal. The systems that carry this signal within the plant and make it reactive are much simpler than an elementary stimulus. We think of a protozoan that we now tickle with a needle, and it flinches, and that's it. In the case of a plant, this reaction can last for weeks or months, and in fact, the whole developmental system of the plant can change as a result.
But we think that the plant is developing what is called proactive behavior, which means that it has some information inside it that is like a map or a memory of some map of the world around it, and it is as if the plant is following that map. This is what distinguishes simple perception from consciousness because it is based on experience and feelings. At the same time, plant neurobiologists are still looking for something similar to the nervous system in plant physiology, and it is even possible to find certain features.
There are, for example, electrical signals that move in the phloem, the system of ducts in the stem, and in the leaves, linking the whole plant together. There are different kinds of electrical signals moving around, and some could be considered to be, in some sense, something like a pain signal. But these signals are, first of all, extremely slow—hundreds of thousands of times slower than what happens at a nerve synapse. Secondly, there is no awareness or sensing factor, which could indicate the existence of more complex sensations or conscious systems.