Let’s start with this view that you propose here. You seem to propose consciousness as something separate from “chemical/mechanical processes” you say that this chemical and mechanical is in opposition to consciousness, so let’s define what you think consciousness is? Most scientists and physicists think that consciousness is indeed an outcome of a chemical combinational structure within the brain, so i’m curious to what you think it is. If you’re so willing to relate that common theory of consciousness to the prospected fallacious ways of that in plant life. Secondly, consciousness, if it exits at all more than from the realm of conceptualizations, is subjective and arbitrarily defined.

And to answer your question, low complexity consciousness could be the exact same as consciousness derived from systems of higher levels of complexity, we simply don’t know, we can only speculate. I see that plants can behave, interact, communicate, and accord oneself to various levels of perceptual stimuli, which is what I would consider a level of sentience or consciousness. Sure maybe plants are unable to recognize themselves as consciousness, but that isn’t what consciousness is about, as only a select few species of primates and bird can, “through experimentation” recognize themselves in a mirror, so to speak. But there does seem to be some level of sentience in accordance with their communication with each other, warning signals, the transfer of goods such as carbon dioxide, the symbiosis of multiple plant life working together in an ecological sense, that displays the same indisputable similarities between human consciousness.

Humans do the exact same thing on an arguably larger scale, in a very different organism, using a very different mean of existing, but that alone is more suggestive of plants having consciousness than only humans having consciousness.