If you watch animals reacting to pain, pretty sure most people (including non-human animals) with a brain can recognise the animals are trying to escape the pain. They audibly scream and cry when in pain. They either try to run away or defend themselves. I'm pretty sure there have been countless experiments on animals that prove beyond any doubt that they experience pain very similarly to us human animals.

We know for a fact that animals have central nervous systems and most people can tell when other sentient beings are in pain because we know how it feels to be in pain ourselves.

Do you honestly believe plants feel pain? Or is it just some kind of weird tactic to justify continuing to enslave, torture and murder animals?

I think you mentioned earlier about people using sound to help plants grow; another way to help plants grow is to prune them. I'm not a gardener by any means, but it seems with many plants the more you prune, the stronger and bigger the plant eventually becomes.

So speaking hypothetically, it's not outside the realms of possibility that if plants were able to feel for some reason, then maybe it does feel good to be cut shorter so that it can come back bigger, stronger and more capable of surviving than before.