ABSTRACT
Plant genetic engineering is perhaps the most obvious example of plant biotechnology that has revolutionized our ability to produce genetically improved plant varieties. On the other hand, it has created some of the biggest controversies in recent times. A large portion of our major crops has undergone genetic improvement through the use of recombinant DNA techniques to which the contribution of microbes has been indispensable. The cross-kingdom transfer of genes to incorporate novel phenotypes into plants has utilized microbes at every step-from the cloning and characterization of a gene, to the production of a genetically engineered plant. This chapter highlights some of the major contributions of microbes to this process. The role of microbes as a source of tools (plasmids and enzymes) to identify and clone desirable genes, as hosts for gene amplification, as a source of DNA cutting and splicing tools (restriction enzymes and ligases), as a direct source of commercially valuable genes, and finally, and as a vehicle for gene transfer into plant cells, are discussed briefly.
