You're confusing these two:
https://en.m.wikipedia.org/wiki/Plant_perception_(physiology)
https://en.m.wikipedia.org/wiki/Plant_perception_(paranormal)
Plants are not sentient
More the one where a tree or other plants get attacked by a certain type of insect and the rest of the trees in the area and somehow start to poison this same type of insect if it eats the their leaves.
That is self defense. Cooperation.
You don't want to believe they're sentient even in the least because it destroys your logic of eating only plants.
Plants are intelligent, but they are not sentient. Just like computers. They're intelligent, but not sentient.
Bacteria are intelligent; in the presence of penicillin, some bacteria will secrete penicillinase (just an enzyme that breaks down penicillin). Bacteria, however, are not sentient.
The wiki links explain all this
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