Actually, with what we know of plants, we absolutely do not know if they are or are not sentient conclusively, and there is plenty of evidence to suggest that they do in fact possess the potential capacity to suffer in as much capacity that animals do, just in ways that would be entirely alien to us due to how different a plant's experience of reality is compared to an animal's. Yet, just because their experience is alien to us doesn't mean they do not have those experiences and the evidence suggests that they do have them.
Plants have complex sensory systems that allow them to communicate, learn, remember, and respond dynamically to external stimuli. They have been found to exhibit Pavlovian responses and collectively manage resources between each other through their root structures and mycorrhizal network.
https://www.nathab.com/blog/research-shows-plants-are-sentient-will-we-act-accordingly
https://regenerationinternational.org/2025/04/20/plant-sentience-changes-everything/
Try clicking links in the listed sources provided and maybe learn about what a secondary source is. Secondary sources ARE credible sources.