Location: Plant Genetics ResearchTitle: Biodiversity of mineral nutrient and trace element accumulation in Arabidopsis thaliana) Author
Submitted to: PLoS One
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/14/2012
Publication Date: 4/27/2012
Publication URL: handle.nal.usda.gov/10113/54149
Citation: Baxter, I.R., Hermans, C., Lahner, B., Yakubova, E., Tikhonova, M., Verbruggen, N., Chao, D., Salt, D.E. 2012. Biodiversity of mineral nutrient and trace element accumulation in Arabidopsis thaliana. PLoS One. 7(4):e35121. Available: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0035121. Interpretive Summary: Understanding how plants regulate element composition of tissues is critical for agriculture, the environment, and human health. Sustainably meeting the increasing food and biofuel demands of the planet will require growing crops with fewer inputs such as the primary macronutrients phosphorus (P) and potassium (K). Ionomics is the study of elemental accumulation in living systems using high-throughput elemental profiling. With this technique, we can rapidly generate large quantities of data on thousands of samples, allowing for the profiling of large genetic mapping populations and the discovery of hundreds of loci important for elemental accumulation. We have used this approach to sample the natural diversity present in collections of a model plant, the wild mustard Arabidopsis. We find that the elemental composition of a plant is tightly controlled by its genes. We also find that elements will have different relationships between them depending on the environment and the tissues (root, seed or leaf) under study. This suggests that crop varieties developed for improved elemental uptake and accumulation will be highly environment specific. These findings contribute to a novel strategy to improve the productivity of all major crops thus impacting world food security in a positive fashion.
Technical Abstract: In order to grow on soils that vary widely in chemical composition, plants have evolved mechanisms for regulating the elemental composition of their tissues to balance the mineral nutrient and trace element bioavailability in the soil with the requirements of the plant for growth and development. The biodiversity that exists within a species can be utilized to investigate how regulatory mechanisms of individual elements interact and to identify genes important for these processes. We analyzed the elemental composition (ionome) of a set of 96 wild accessions of the genetic model plant Arabidopsis thaliana grown in hydroponic culture and soil using inductively coupled plasma mass spectrometry (ICP-MS). The concentrations of 17-19 elements were analyzed in roots and leaves from plants grown hydroponically, and leaves and seeds from plants grown in artificial soil. Significant genetic effects were detected for almost every element analyzed. We observed very few correlations between the elemental composition of the leaves and either the roots or seeds. There were many pairs of elements that were significantly correlated with each other within a tissue, but almost none of these pairs were consistently correlated across tissues and growth conditions, a phenomenon observed in several previous studies. These results suggest that the ionome of a plant tissue is variable, yet tightly controlled by genes and gene x environment interactions. The dataset provides a valuable resource for mapping studies to identify genes regulating elemental accumulation. All of the ionomic data is available at www.ionomicshub.org.