Molecular Plant Advance Access originally published online on July 6, 2009
Molecular Plant 2009 2(5):922-932; doi:10.1093/mp/ssp046
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Microanalysis of Plant Cell Wall Polysaccharides
a Max-Planck-Institut for Molecular Plant Physiology, Am Mühlenberg 1, 14476 Golm, Potsdam, Germany
b Present address: European Patent Office, Erhardtstrasse 27, Munich, Germany
c Helmhotz Center Munich, Institute of Biological and Medical Imaging, Ingolstaedter Landstrass. 1, 85764 Neuherberg, Germany
d Wageningen University, Department of Agrotechnology and Food Sciences, Laboratory of Food Chemistry, Bomenweg 2, 6703 HD Wageningen, The Netherlands
e DOE Plant Research Lab., Michigan State University, East Lansing, MI 48864, USA
1 To whom correspondence should be addressed. E-mail paulymar{at}msu.edu, fax +1-517-353-9168, tel. +1-517-353-4333.
Oligosaccharide Mass Profiling (OLIMP) allows a fast and sensitive assessment of cell wall polymer structure when coupled with Matrix Assisted Laser Desorption Ionisation Time Of Flight Mass Spectrometry (MALDI–TOF MS). The short time required for sample preparation and analysis makes possible the study of a wide range of plant organs, revealing a high degree of heterogeneity in the substitution pattern of wall polymers such as the cross-linking glycan xyloglucan and the pectic polysaccharide homogalacturonan. The high sensitivity of MALDI–TOF allows the use of small amounts of samples, thus making it possible to investigate the wall structure of single cell types when material is collected by such methods as laser micro-dissection. As an example, the analysis of the xyloglucan structure in the leaf cell types outer epidermis layer, entire epidermis cell layer, palisade mesophyll cells, and vascular bundles were investigated. OLIMP is amenable to in situ wall analysis, where wall polymers are analyzed on unprepared plant tissue itself without first isolating cell walls. In addition, OLIMP enables analysis of wall polymers in Golgi-enriched fractions, the location of nascent matrix polysaccharide biosynthesis, enabling separation of the processes of wall biosynthesis versus post-deposition apoplastic metabolism. These new tools will make possible a semi-quantitative analysis of the cell wall at an unprecedented level.
Key Words: Carbohydrate metabolism • xyloglucan • mass spectrometry • cell expansion • cell walls • Arabidopsis • laser microdissection