Arabidopsis mutant lines showing hormone-independent growth and differentiation in vitro. A loss of this control will eventually lead to the formation of unorganized tissue growth, i.e. plant tumors.
Tumors can grow in vitro as calli on hormone-free media.
We have isolated 16 lines which dedifferentiate and are able to grow subsequently as callus on hormone-free medium. We distinguish three mutant classes based on their differentiation behaviour. Also an altered transcript accumulation of meristem-specific homeobox genes and of genes implicated in the regulation of cell division was found in some of the mutant lines. These markers allowed the distinction of phenotypically similar lines, indicating that likely unrelated mutations can lead to similar phenotypes.