PHYTONUTRIENT BIOCHEMISTRY, PHYSIOLOGY, AND TRANSPORT
Location: Children Nutrition Research Center (Houston, Tx)
Title: Quantitative trait locus mapping for seed mineral concentrations in two Arabidopsis thaliana recombinant inbred populations
Submitted to: New Phytologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 8, 2008
Publication Date: September 6, 2008
Citation: Waters, B.M., Grusak, M.A. 2008. Quantitative trait locus mapping for seed mineral concentrations in two Arabidopsis thaliana recombinant inbred populations. New Phytologist. 179:1033-1047.
Interpretive Summary: Seeds are an important source of dietary minerals for humans, but our understanding is incomplete regarding how minerals move from soil, into and through the plant, and eventually to seeds. One way to study the processes that contribute to the whole-plant movement of minerals is to use special populations of plants that have defined genetic characteristics. We grew two such populations of the model plant Arabidopsis, and harvested seeds in order to analyze seed mineral concentrations. Statistical tests of the mineral results allowed us to identify specific regions within the plant's DNA, which were associated with genes that contributed to high levels of seed minerals. These results will allow us to identify specific genes that could lead to nutritionally improved crops.
Biofortification of foods, achieved by increasing the concentrations of minerals such as Fe and Zn, is a goal of plant scientists. Understanding genes that influence seed mineral concentration in a model plant such as Arabidopsis could help in the development of nutritionally enhanced crop cultivars. Quantitative trait locus (QTL) mapping for seed concentrations of Ca, Cu, Fe, K, Mg, Mn, P, S, and Zn was performed using two RIL populations, Col x Ler and Cvi x Ler, grown on multiple occasions. QTL mapping was also performed using data from silique hulls and the ratio of seed:hull mineral concentration of the Cvi x Ler population. Over 100 QTL that affected seed mineral concentration were identified. Twenty-nine seed QTL were found in more than one experiment, and several QTL were found for both seed and hull mineral traits. A number of candidate genes affecting seed mineral concentration are discussed. Our results indicate that A. thaliana is a suitable and convenient model for discovery of genes that affect seed mineral concentration. Some strong QTL had no obvious candidate genes, offering the possibility of identifying unknown genes that affect mineral uptake and translocation to seeds.