I intend to write an adventure novel where the protagonist is a (divine) plant. Though it cannot move or speak, it's necessary for the plant to be the main protagonist (there will not be any subplots). There will be humans, but there dialogue and representation as a percentage of text will be so tiny that the readers will know they are not the protagonists. This much I'm somewhat confident of -- however, since the plant is not a sentient being, I don't know how to integrate the story into conventional storytelling for things like "the fateful decision?"
The protagonist makes key decisions that affect the plot, primarily influencing the story and propelling it forward, and is often the character who faces the most significant obstacles.
Having a non-sentient being act as a protagonist to facilitate conventional plot devices, such as making decisions is challenging. The best I could do was write it off as a divine plant, and its "decisions" appear as omens: an eclipse, something auspicious for "yes" something bad for "no".
However, I'm not trying to write a magical/fantasy adventure book. I want to keep it as scientific as possible. So I'd like to see if there are other viable writing frameworks rather than throwing magic at all my problems.
Is there anything in the existing literature that could be a useful reference for maximizing traditional plot devices when given a non-sentient protagonist?