The Use of Genomics
Strategy for creating a more stress-tolerant plant using genetic engineering
The definition of the term genomics is rapidly evolving and expanding: genomics makes use of a variety of technologies that allow organisms to be described at DNA, mRNA, protein, and metabolite levels and allow relationships within and among these levels to be deciphered, both during growth and development and in response to various environmental stimuli. Genomics seeks to provide a complete, integrated, and multipurpose set of consistent data harbouring the answers to a multitude of questions. The resulting data can be systematically and repeatedly analysed and mined using bioinformatics to provide the information needed to address various problems and to answer a multitude of questions (many of which have not yet been imagined) using unbiased data analysis programs. In the near future, approaches allowing recombination hotspots to be highlighted will further aid plant-breeding efforts. Germ plasm improvement will continue to depend on non-transgenic methods that use sophisticated assays and molecular genetic markers to identify and exploit relevant genetic combinations, while genomics will accelerate the discovery of genes that confer key traits, enabling their rapid modification.
Transformation
The isolation of single genes involved in stress tolerance and the possibility of testing these genes in a new genetic context can be accomplished by molecular genetics. Different strategies can be adapted by molecular biologists to reveal the basic parameters of stress tolerance. One strategy is to take a tolerant plant and ask which molecules are the basis for tolerance. Using this method, an array of stress-induced genes have been isolated.
A second strategy is to take non-tolerant plants and transform them with given genes and assess the effect of these genes on stress tolerance. A crucial point in this procedure is the selection of the genes used for transformation, and this is where the two strategies overlap. The genes can also come from several soucres such as animals, bacteria or yeast.
Two main types of method for plant transformation exist, the use of Agrobacterium as a biological vector for foreign gene transfer, and direct gene transfer techniques, in which DNA is introduced into cells by the use of physical, electrical or chemical means.