15th International Conference on Arabidopsis Research - TAIR

T07-097
Ionomics: Gene Discovery in Aid of Plant Nutrition,
Human Health and Environmental Remediation
Guerinot, M.L.(1), Eide, D.J.(2), Harper, J.F.(3), Salt, D.E.(4), Schroeder, J.I.(5) and
Ward, J.M.(6)
1-Department of Biological Sciences, Dartmouth College, Hanover, NH 03755
2-Department of Biochemistry, University of Missouri, Columbia, MO 65211
3-Biochemistry Department, University of Nevada-Reno, Reno NV 89557
4-Center for Plant Environmental Stress Physiology, Purdue University, West Lafayette, IN 47907
5-Division of Biological Sciences, UCSD, La Jolla, CA 92093-0116
6-Department of Plant Biology, University of Minnesota, St. Paul, MN 55108
Increasing the ability of plants to take up minerals could have a dramatic
impact on both plant and human health. Furthermore, understanding the
pathways by which metals accumulate in plants will enable the engineering
of plants to exclude toxic metals or to extract toxic metals from the soil. We
have employed mineral nutrient and trace element profiling (via ICP-MS or
ICP-AES) as a tool to determine the biological significance of connections
between a plant’s genome and its elemental profile. Our focus is on genes
that control uptake and accumulation of solutes, including N, P, Ca, K, Mg
(the macronutrients in fertilizer), Cu, Fe, Zn, Mn, Co, Ni, Se, Mo, I (micronutrients
of significance to plant and human health), Na, Pb, Al, As, and Cd
(metals causing agricultural or environmental problems). The ion profile of
4429 mutants from the commercially available yeast knockout collection has
been completed, yielding new insights into the role of the vacuole and the
mitochondria in metal metabolism. We have also completed a proof-ofconcept
screen of over 6000 FN mutagenized Arabidopsis plants (Lahner et
al., 2003 Nat. Biotechnol. 21:1215) and we are currently screening the Salk
collection of T-DNA insertion alleles. The long-term goal is to quantify the
functional contribution to mineral nutrition and ion homeostasis of every gene
in Arabidopsis. To maximize the value of this ionomics approach, we have
developed a searchable online database containing ionomic information on
over 22, 000 plants.
http://hort.agriculture.purdue.edu/Ionomics/database.asp
15 th <strong>International</strong> <strong>Conference</strong> on Arabidopsis Research 2004 · Berlin
T07-098
Functional Genomics of Carbon-Nitrogen Interactions
M.Stitt(1)
1-Max Planck Institute for Molecular Plant Physiology, Am Mühlenberg 1, 14476 Golm, Germany
Carbon-nitrogen interactions provide a good system to explore the use of
system-orientated approaches to improve understanding of complex biological
systems. The use of carbon and nitrogen are closely intertwined with
each other, and has important consequences for a wide range of downstream
processes, including metabolism but also in growth-related processes and
development. Nevertheless, many basic structural features of the network are
known, at least in the area of primary metabolism, which aids experimental
planning and the interpretation of the results, I will discuss how a range of
phenotyping platforms including commercial expression arrays, multiplexed
real time RTR-PCR for > 1200 transcription factors, robot-based enzyme
assays and metabolite profiling are being used to characterise the response
to changes in the carbon and nitrogen supply. Various bioinformatics approaches
are used to analyse the results, including MapMan, a simple software
tool that allows genomics data sets to be displayed on diagrams of biological
processes. The results will be used to illustrate some general points about
the relation between changes of transcripts, proteins/enzyme activities and
metabolites, to provide a detailed molecular characterisation of the global
response to changes in nitrogen and carbon, and to show how this approach
allows novel genes to be identified that can be highlighted for subsequent
details functional analysis.
T07 Metabolism (Primary, Secondary, Cross-Talk and Short Distance Metabolite Transport)