When the subject is opened from veganism or vegetarianism, one of the places where the conversation turns around is that the plants do not suffer like animals. Can plants really suffer like animals?
One of the most useful methods for reasoning in biology is to perform induction by reviewing evolutionary processes.
The main factor in the evolution of the nervous system in a living being is mobility. Mobility: It is essential to find food, to breed and to avoid creatures that can rival it both now and in the future. The fact that a living thing that cannot move has the ability to suffer is not an evolutionarily logical strategy. Plants do not suffer, but, like all living things in nature, they react to external stimuli, if not, they would not be considered alive.
If an animal has been subjected to a physical (let’s emphasize that it is physical) threat to life, its body reacts to it. Many pathways become active to repair tissue damage. Pathway: They are notification systems that enable certain changes in the cell to occur by interacting with biological mechanisms, proteins and other biological molecules. For example, the insulin pathway, which is not related to repairing tissue damage, but will allow them to understand: insulin delivered to the blood binds to insulin receptors in the body, and the insulin pathway is activated by interacting with some signal molecules under the receptor.
In addition to repairing tissue damage, one of the reactions the body needs to take is immediate action to get away from the dangerous stimulus. Because if it is not moved quickly enough, the damage can become irreversible or result in death.
There is a cognitive (information processing) process as well as a physical process of feeling pain. The nervous system does not only work on instant reaction and avoiding danger. It is also necessary to keep the acquired knowledge in order to increase the probability of survival in the future.
A cut in the leaf of the plant causes calcium fluctuations. This is a known phenomenon in multicellular organisms. Calcium provides intracellular and intercellular message transmission. Calcium plays a role in signal transduction in hormone pathways in the animal body (the pathway system I mentioned earlier).
In the nervous system, there is signal transmission between neurons. Signal transmission enables the processing of information and takes place based on neuronal voltage changes. Of course, calcium delivery is also present in the brain to inform the local state of the glial cells. However, the aim here is to spread local information both within the cell and to report it to other cells. The process of information processing through notification is different, and the process of suffering is related to the processing of information.
There is no signal transmission (voltage change for information processing) in plants. Plants may be using voltage systems to react, but this does not mean that they are using it for signal transmission or information processing. Because voltage changes in the nervous system can be transferred to cells of the same type as if it were an electrical line, and specialized cells are required for that purpose (neuron) in order for this to happen.
Plants have signal transduction and hormonal transmission instead of neuronal signal transmission (notification). If this kind of notification takes up to 2 minutes to propagate, this is not a process of suffering, it is the process of reporting, and that is the situation in plants. Suffering processes need to be faster.
The purpose of the system here is that the damaged part of the plant sends local signals and informs the living thing about tissue damage so that resources can be provided for repair, genes become active and protein synthesis begins. So, it’s actually a hormonal signal rather than a pain signal. Like the coagulation pathway that is active when you cut your finger.
Meanwhile, the fact that the receptor responsible for this process in plants is the glutamate receptor and that it plays a role in the learning and memory processes in the nervous system does not constitute anything other than the fact that it is functionally well maintained under evolutionary conditions. This only shows evidence that there is a primitive response system in plants. It does not mean that they are in pain. Complex processes such as pain do not occur in the absence of more complex anatomical structures, systemic organization, and plasticity, so neurons are needed. This is the case with plants.
In cognitive systems such as pain, the existence of learning, acting and advanced perception systems is essential for a process that requires the processing of information. Although these are not in plants, this research only shows that there is a long-distance reporting system in plants.