The answer to this question is the term rhizome. A rhizome is a stem of a plant that is growing underground and is growing horizontally. It is also known as rootstocks. The rhizome's function in the plant is that it is used to store starches and protein that enables the plant to grow underground.
I’m not sure I understand your question.
Most likely, it would effect many trees depending on the rate of infection and how much of this microorganism is released to the environment. I hope that helped :)
The correct answer is water