That plants do feel is about as improbable as it is that animals (including humans) do not feel. (The only real uncertainty is about the very lowest invertebrates and microbes, at the juncture with plants, and evidence suggests that the capacity to feel depends on having a nervous system, and the behavioral capacities the nervous system produces.)

Because animals feel, it is unethical (in fact, monstrous) to harm them, when we have a choice. We don’t need to eat animals to survive and be healthy, so there we have a choice.

Plants almost certainly do not feel, but even if they did feel, we would have no choice but to eat them (until we can synthesize them) because otherwise we die.