Research in the plant molecular biology group focuses on the identification, characterisation and exploitation of genes which regulate xylem architecture, or which are active in the cambial region of plants. Two model systems,the transformable woody plant Populus tremula x tremuloides, and the dicotyledonous annual plant Arabidopsis thaliana are used. Key genes spatially regulated during plant development are identified and isolated using a number of different approaches. In these studies a novel sub class of homeobox genes has been found that is only expressed in the xylem maturation zone. A ribosomal protein gene copy expressed in the cambial region and possibly involved in growth regulation, has been identified. Isolated genes are over-, and antisense expressed in transgenic Populus and Arabidopsis. Promoter-reporter gen fusions are also introduced into the model plants. Regenerated, transgenic plants are studied by physiological, molecular and anatomical methods.