Metabolic Profiling

Metabolites represent the end products of gene expression. Comprehensive metabolic profiling or "metabolomic" studies offer a definitive view of the metabolic status of an organisms. This view serves as a insightful tool when used to study gene function or systems biology and is therefore being used to study Medicago truncatula. Although powerful, metabolomics is still an evolving science and very technically challenging. To meet these challenges, we have designed a strategy that utilizes sequential or selective extraction followed by parallel analyses. Our parallel analyses utilize an arsenal of analytical techniques to achieve a comprehensive view of the metabolome and include: high-performance liquid chromatography (HPLC), capillary electrophoresis (CE), gas chromatography (GC), mass spectrometry (MS), and various combinations of the above techniques such as GC/MS, LC/MS, and CE/MS.

Profiling of the isoflavonoid medicarpin from a yeast elicitor-treated cell suspension culture of M. truncatula. Trace A shows a total ion chromatogram obtained by LC/MS. The inset shows the mass spectrum for the medicarpin peak, identical to that of authentic medicarpin. Trace B shows a similar HPLC separation, but with photodiode array detection. The inset shows the UV-visible absorption spectrum of the medicarpin peak.

Sequential extraction segregates the metabolome into more manageable classes of chemical compounds with similar physical/chemical properties thereby facilitating the use of parallel analytical profiling techniques. Methods are currently being employed or developed for the profiling of most primary and secondary plant metabolites including: soluble sugars, sugar phosphates, complex carbohydrates, amino acids, organic acid, alcohols, fatty acids/lipids, sterols, phenylpropanoids, lignins, and terpenoids saponins.  

Metabolomics is currently being used to study

	Biological responses to biotic and abiotic elicitors in Medicago truncatula cultures
	Medicago truncatula natural variants
	Medicago truncatula development
	Lignin biosynthesis
	Gene function in transgenic legumes
	Legume-Insect interactions

See Also:
The Sumner Group: Bioanalytical Chemistry and Mass Spectrometry

References