Breakthrough in genetic modification of grains

Despite years of effort, it has been remarkably difficult to develop efficient methods for transformation (i.e., genetic modification) of grain crops. The preferred methods generally involve infecting tissue with Agrobacterium -- a bacterium that naturally transfers DNA to its host genome -- and then stimulating that tissue to regenerate into whole plants. However, Agrobacterium infects only a narrow range of grain cultivars, and many cultivars are recalcitrant to regeneration. A paper published in The Plant Cell reports a breakthrough in transformation technology that greatly expands the range of cultivars and species that can be transformed.

A team of researchers from DuPont added so-called morphogenic genes -- known from basic research to promote the production of embryonic tissue -- to the other genes being transformed (in this case to express green fluorescent protein as a marker of transformation). When they did so, transformation rates increased for a large number of maize cultivars -- in many cases going from essentially no transformation to rates high enough for efficient use in commercial and research applications. The technique also worked in sorghum, rice and sugarcane. This work extends the range of species, cultivars and tissues that can be used for efficient transformation and is a beautiful example of what can be accomplished by combining basic research, technical expertise, and knowledge of practical problems facing mainstream applications.