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United States Department of Agriculture

Agricultural Research Service

Hoekenga
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Owen Hoekenga
Molecular Biologist
Phone: (607) 255-4502
Fax: (607) 255-1132
E-mail: Owen.Hoekenga@ars.usda.gov
Research Interests

The primary goal of my research is to understand the genetic and environmental bases for crop quality, using tomato and corn as model systems. The emphasis for the tomato project is to estimate the boundaries for consumer, regulator and producer acceptable chemical diversity using a collection of heirloom and modern breeding varieties. By estimating the boundaries of acceptable variation, we can better assess the importance and significance of variation seen in transgenic tomatoes that we have generated. This information should allow consumers, regulators and other concerned parties to make better decisions regarding biotechnology risk assessment and the safety of transgenic crops. We have used mass spectrometry (MS) and nuclear magnetic resonance (NMR) based approaches to determine the chemical composition of tomato varieties.

The emphasis for the corn project is to improve the nutritional quality of the important staple crop, with respect to iron bioavailability. Plant-based foods do not provide iron in a form that is easily absorbed by people. People who rely on monotonous diets dominated by a starchy staple food crop are often iron deficient or anemic. Nearly half of the people on the planet are iron deficient or anemic, thus understanding the genetic and environmental bases for iron bioavailability can potentially improve the quality of life for many people. We identified several quantitative trait loci (QTL) in maize that affect iron nutritional quality, according to bioassays performed with a human cell line, and isolated these QTL in new varieties. Recently, collaborators performed feeding studies that used our new, conventionally bred corn varieties and young broiler chickens to further validate these QTL. The next phase will be to use the same MS and NMR-based chemical profiling techniques we used for biotechnology risk assessment in tomato to identify compounds that may be responsible for the alterations in corn nutritional quality. The chemical profiling will be used to help direct our molecular genetic and genomics-based research, to identify the genes that underlie the nutritional quality QTL.

Last Modified: 3/18/2010