My research focuses on bridging the chasm between plant biology and nutritional sciences. Generations of nutritional scientists have cataloged the nutrients in foods, while in the last decade plant genome projects have facilitated the development of genetic tools to manipulate nutrient content; however, few studies have assessed the impact that these genetic modifications have on nutrient bioavailability. It is my working hypothesis that bioavailability is determined by the allocation of nutrients within plant cells and that emphasis should be placed on increasing the bioavailable portion of nutrients not simply on increasing the bulk amounts of nutrients in food.
Using crop plants (carrots/potatoes/tomatoes), we utilize molecular genetics to systematically repartition calcium (Ca) within the plant matrix. We then use animal and human feeding studies to address bioavailability. Our hypothesis is that the intracellular location of Ca within the plant cell will influence nutrient absorption.
The Vegetable and Fruit Improvement Center (VFIC) in collaboration with the Children’s Nutrition Research Center (CNRC) offers a unique research environment. Plants can be made and nutritional studies done. A) Transgenic plants can be generated in our research labs. B) Plants can be labeled with radioisotopes or stable isotopes in our greenhouses. C) and D) Commercial or transgenic fruits and vegetables can be evaluated in mice feeding regimes. E) The biofortified fruits and vegetables can be used in human feeding studies at the CNRC.
Our work also addresses how alterations in Ca content can alter plant quality and processing characteristics. We have demonstrated alterations in fruit shelf life through altering Ca transport activity and continue to address how altering Ca in the plant impacts fruit and vegetable taste and texture.
Representative Publications:
Park S, Elless MP, Park J, Jenkins A, Lim W, Chambers IV E, Hirschi KD (2009). Sensory analysis of calcium-biofortified lettuce (Cover). Plant Biotechnol J. 7(1):106-117.
Morris J, Hawthorne KM, Hotze T, Abrams SA, Hirschi KD (2008) Nutritional impact of elevated calcium transport activity in carrots. PNAS. 105(5):1431-1435.