Submitted to: Weed Technology
Publication Type: Review Article
Publication Acceptance Date: December 28, 2001
Publication Date: October 1, 2001
Technical Abstract: Crop allelopathy has seldom been effective enough to be used by farmers in weed management. Traditional breeding methods have not been very successful in producing highly allelopathic crops. Genetic engineering may offer more effective methods of overcoming this impasse. Crops have been made resistant to insects, pathogens, and herbicides with transgenes, but biotechnology has not produced crops that control weeds with allelochemicals. The strategies for producing allelopathic crops by biotechnology are relatively complex, usually involving multiple genes. One can choose to enhance production of allelochemicals already present in a crop or to impart the production of new compounds. The first strategy involves identification of the allelochemical(s), determination of the enzymes and genes encoding them, and the use of genetic engineering to enhance production of the compound(s). The latter strategy employs altering existing biochemical pathways by insertions of transgenes to produce new allelochemicals. Either strategy has potential problems with tissue-specific promoters, autotoxicity, metabolic imbalances, and proper movement of the compound to the rhizosphere.