The molecular mechanisms underlying control of growth and differentiation in higher plant cells remain unknown. In order to systematically isolate and functionally characterize genes from higher plant cells involved in control of growth and differentiation, we have applied both conventional and novel strategies. We have used modern microanalytical techniques to isolate and study various auxin-binding proteins. We shall discuss the molecular structure of different putative auxin-receptor genes from Z. mays and A. thaliana. Using homology probing we have identified and isolated a series of genes involved in plant signalling processes including members of the RAS-gene family. The isolation of other genes relies on the study of different procaryotic genes known to have a marked effect on plant differentiation. These are T-DNA linked genes from A. tumefaciens and A. rhizogenes as well as genes from Rhizobiacae. Finally various gene tagging approaches will be discussed that are presently used to identify and isolated genes involved in developmental control of plants.