What are the reasons that excess IBA in a dicot seed will inhibit its germination?

What are the reasons that excess IBA in a dicot seed will inhibit its germination?
What are the reasons that excess IBA in a dicot seed will inhibit its germination?

I have asked this question before and appreciate the previous answer, however I think I was expecting something else...

At the cellular level, what are the reasons that excess IBA inhibits the germination of a dicot seed (or any plant I suppose)? I conducted an experiment at school where I concentrated soybean seeds with IBA solution. However, I later found that concentrations above 1% will inhibit the seed's germination (as per Narmin Asri's report in 1995).

Basically, I want to know what goes on in the cells/seed when there is excess IBA (or any auxin) that causes is to become dormant.

THANKS