ABSTRACT
The most common method for inserting alien genes into plant cells and subsequently regenerating transgenic plants is plant transformation mediated by Agrobacterium tumefaciens. A. tumefaciens is a soilborne plant pathogenic bacterium that infects wound sites in dicotyledonous plants and causes crown gall tumours. This chapter presents the latest information on the mechanisms of A. tumefaciens-mediated gene transfer. The application of this method to the transformation of monocotyledonous plants has been analysed, taking sugarcane as a model. The transfer of genes from A. tumefaciens to plant cells involves several necessary steps: colonization of bacteria, induction of bacterial virulence system, formation of T-deoxyribonucleic acid (DNA) transfer complextransfer of T-DNA, and integration of T-DNA into plant genome. The earliest and essential step in the induction of tumour is bacterial colonization, which occurs when A. tumefaciens attaches itself to the plant cell surface. In the colonizing process, polysaccharides of A. tumefaciens cell surface play an important role.
