Adjunct Scientists

Owen Hoekenga

The emphasis of my research program is assessing unintended effects of transgenic crop improvement on plant composition, quality and performance. According to the National Agricultural Statistical Service, transgenic crops made up a majority of US acreage planted in 2007. In spite of this (or perhaps because of this), a debate exists between supporters and opponents of transgenic crops regarding the demonstrated or presumed safety of these varieties to people, animals and the environment. Two important concepts in the debate over transgenic crop safety are substantial equivalence (SE) and generally regarded as safe (GRAS). SE is the concept that a transgenic variety is so highly similar to its non-transgenic parent, that it can be considered to be the same. Opponents of transgenic crop improvement have criticized this concept for being without statistical merit or utility for risk assessment. In the plant improvement context, GRAS means that we accept that the products of conventional plant breeding (i.e., new varieties) are safe. Thus, the differences that exist between conventionally improved plant cultivars represent a threshold that is acceptable to consumers, regulators and other stakeholders. We examine the differences between conventionally and transgenically modified varieties from a standpoint of GRAS, to evaluate SE in a statistically rigorous manner. I am using fruit ripening in tomato as a model system of known agronomic importance and use a number of experimental approaches. I am also conducting research in two different plant-metal interactions using corn as a model system. First, I am interested in stress tolerance to toxic aluminum in roots, which is largely a natural problem related to soil acidity and a major limitation to crop yield and thus food security. Second, I am interested in iron nutritional quality in seeds, working to biofortify this important staple crop.

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