Plants feel pain.
Maybe they do. I don't know.
What I do know is animals feel pain. I know that the majority of land animals in the UK are fed tonnes of plants. So if plants do feel pain then being Vegan would cause the least amount of harm.
When people bring up plant feelings I also ask them if they walk on grass and walk on puppies. Most people say they don't walk on puppies, this says to me that they, like Vegans, treat plants and animals differently.