Cellulose Synthase-Like Genes: Physcomitrella as a heterologous expression system for investigating
the functions of CESA-like gene products
(Collaborators: Allison Roberts, Aaron Liepman & William Willats) |
| Cellulose synthase-like (CSL) genes are proposed toencode glycan
synthases that polymerize the backbones of non-cellulosic cell wall
polysaccharides. Consistent with this hypothesis, CSLA genes are known
to encode mannan synthases and a CSLF gene is implicated in
mixed-linkage-glucan synthesis. Members of the CSLB, CSLE, CSLG, and
CSLH families have not been functionally characterized. The complete
genome sequence of the moss Physcomitella patens lacks members of these
CSL families. We are using Physcomitrella as a heterologous expression
system to investigate the functions of the proteins encoded by CSLB,
CSLE, CSLG, and CSLH genes from seed plant species, including rice,
poplar, and Arabidopsis. Transgenic Physcomitrella expressing CSLB,
CSLE, and CSLG genes from Arabidopsis have been produced. The overall objectives
of this collaborative project are to 1) develop additional transgenic lines that
express CSLB, CSLE, CSLG, and CSLH genes from rice and poplar, 2) screen
transgenic lines for changes in cell wall polysaccharide composition
using a novel Comprehensive Microarray Polysaccharide Profiling method,
3) analyze the cell wall polysaccharides of transgenic Physcomitrella
for the presence of novel linkages, 4) develop in vitro assays to
identify the catalytic activity of the heterologously-expressed CSL
proteins, and 5) examine the development and stress response of
transgenic Physcomitrella containing novel cell wall polysaccharides.
Non-cellulosic cell wall polysaccharides impact the pulping properties
of wood, the mechanical properties of textiles fibers, the health
effects of dietary fiber, and the efficiency of energy extraction from
biofuels.
Funding source: USDA NRI-GCP, Plant Biology
http://www.usda.gov/wps/portal/usdahome
Colaborators: Alison Roberts at University
of Rhode Island, Aaron Liepman, Wayne
State University and
William Willats, Københavns Universitet, Denmark |
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