Improving plant genetic engineering by manipulating the host.

Agrobacterium-mediated transformation is a major technique for the genetic engineering of plants. However, there are many economically important crop and tree species that remain highly recalcitrant to Agrobacterium infection. Although attempts have been made to "improve" transformation by altering the bacterium, future successes might come from manipulation of the plant. Recent studies that identified several plant genes involved in Agrobacterium-mediated transformation, and their over-expression in currently transformable species, suggest that this approach holds great promise for improving the transformation of recalcitrant, but agronomically important, crops.