Plants do not have a brain, nervous system, or anything else to suggest that they have the capacity to feel pain or suffer. If you stab a carrot, apple or grain of rice (for example) it will not react or attempt to avoid the knife in any way. I've not seen any reliable source of information to suggest that any plants commonly eaten by humans have sentience or can feel pain. If you have seen something that proves otherwise I would be interested to read it.

Even if such evidence exists, it is still not a valid argument against veganism anyway, because livestock actually consumes far more food than it produces. If you really cared about the "feelings" of plants it would still make sense to go vegan, since so many of them are grown just to become animal feed. Going plant based would equal less plants being consumed overall than with an omnivorous diet.