Plant, Animal & Microbe Genomes X Conference Plant, Animal & Microbe Genomes X ConferenceJanuary 12-16, 2002
Town & Country Convention Center
San Diego, CA
Workshop: Arabidopsis
Metabolomic analysis aims at the unbiased relative quantification of all metabolites of a biological system, e.g. a plant organ. It must not a priori exclude any class of compounds by its means of sample preparation, analytical instrumentation, or data processing. Therefore, initial methods of "metabolite profiling" that were primarily detecting and quantifying small molecules by GC/Quadrupole MS were extended on the one hand to a faster GC/TOF MS method that enables the detection of >750 compounds in a single 20-min-run by improved data deconvolution. On the other hand, any bias towards large oligosaccharides and sugar nucleotides was abolished by applying hydrophilic interaction chromatography/ion trap MS. Arabidopsis leaf disks (60 mg FW) were harvested at the same developmental stages, and the application of unbiased GC/TOF analysis on Arabidopsis accessions and crosses of these is presented. Metabolite extraction and derivatization was performed under mild conditions applying novel protocols. After GC/TOF and LC/ion trap MS analysis, relative abundance of all detectable peaks were evaluated with respect to statistical differences, metabolic phenotypes, and differences in metabolic networks. Metabolic phenotypes were derived from principal component analysis and used for assessing relative metabolic distances of Arabidopsis accessions. Metabolic networks were generated by calculating metabolite-metabolite correlations (i.e. metabolite co-response factors), and network connectivities were shown to be distinct for each accession analysed.