Progress 02/01/07 to 01/31/12
Outputs
OUTPUTS: We have studied xyloglucan biosynthesis by expression profiling in developing nasturtium seeds. We have also studied xyloglucan biosynthesis using reverse genetics in Arabidopsis. Finally, we have begun studying galactomannan biosynthesis by expression profiling in fenugreek. Some of our results have been published in scientific journals during the last year; others results are being prepared for submission to scientific journals. Still others are too preliminary, alhtough some of these results will be presented at scientific meetings in 2008.
PARTICIPANTS: Aaron Liepman, Olivier Lerouxel, and David Cavalier are postdoctoral associates who have been working in our laboratory. They received training in this area of research. Olivier now has a faculty position in Grenoble, France and Aaron has a faculty position at Eastern Michigan University. David is still in our laboratory. Curtis Wilkerson is a collaborator who now has a faculty position in the Department of Plant Biology. Jean Chrisophe Cocuron is a technician working with Curtis Wilkerson. The others are all collaborators at other institutions.
TARGET AUDIENCES: Other scientists working on plant cell wall polysaccharide biosynthesis. This work has become increasing relevant to a wider audience as many people become interested in using plant cell walls a source of sugars for producing biofuels.
PROJECT MODIFICATIONS: none
Impacts
The most important conclusion published during the past year was that the glucan synthase activity responsible for the biosynthesis of the backbone of xyloglucan is encoded by a gene in the C family of cellulose synthase like genes. The hint that this gene was a likely candidate came from profiling of gene expression in developing nasturtium seeds, a system that produces large quantities of xyloglucan. The CSLC candidate genes from nasturtium and Arabidopdis were expressed in yeast cells leading to the demonstration that these cells now produced novel glucan oligosaccharides and polysaccharides that were not present in normal yeast cells. Another important finding was the obseration that CSLA genes from several different plant species encoded mannan synthase enzymes that are involved in galactomannan biosynthesis.
Publications
- Liepman AH, Cavalier DM, Lerouxel O, Keegstra K (2007) Cell Wall Structure, Biosynthesis, and Assembly. In: Roberts JR and Gonzalez-Carranza Z (eds) Plant Cell Separation and Adhesion, Annual Plant Reviews, Vol 25, pgs 8-39.
- Liepman AH, Nairn CJ, Willats WGT, Sorenson I, Roberts AW, Keegstra K (2007) Functional genomic analysis supports conservation of function among CslA gene family members and suggests diverse roles of mannans in plants. Plant Physiol, 143: 1881-1893.
- Cocuron J-C, Lerouxel O, Drakakaki G, Alonso AP, Liepman AH, Keegstra K, Raikhel N, Wilkerson CG (2007) A gene from the cellulose synthase-like C family encodes a β-1,4 glucan synthase. Proc Natl Acad Sci USA, 104:8550-8555.
- Faure R, Cavalier D, Keegstra K, Cottaz S, Driguez H (2007) Glycosynthase-assisted synthesis of xylo-gluco-oligosaccharide probes for α-xylosyltransferases. Eur J Org Chem, 2007: 4313-4319.
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