Plants do have incredibly impressive defence mechanisms, but that doesn’t mean onions are crying when you cut them. There’s no central nervous system, you are anthropomorphising. That is very common whenever this topic comes up, but it really is magical thinking, and the garden is already magical enough without imagining fairies at the bottom.
Why doesn’t it mean onions are crying out? Why is a nervous system necessary for pain or suffering? How can we know that? How am I anthropomorphizing if we do not have a functional universal definition of ‘suffering?’ If you’re going to make that claim, you’re going to say I can’t prove cows suffer.
I studied plant signalling/phytohormones during my MSc, it’s genuinely fascinating but it doesn’t imply consciousness. Cows have a central nervous system. Beyond that, it’s magical thinking. You are making an unfalsifiable claim, and that’s fine, but please acknowledge that you are adopting a faith-based position here. I could claim the sentience of crystals and be similarly obstinate when challenged.