| Abstract Detail
Cell Walls Walton, Jonathan [1]. Light regulation of cell wall biosynthesis in the maize mesocotyl. We are using etiolated maize seedlings as a model system for studying cell wall biosynthesis. When 5-day-old maize seedlings are exposed to light, the rapid elongation of the maize mesocotyl stops. To gain a better understanding of the developmental regulation of cell wall biosynthesis, light-regulation of cell wall related enzymatic activities, including (1,4)-β-glucan synthase, (1,4)-β-mannan synthase, an UDP-galactose incorporating activity, (1,4)-β-xylan synthase and (1,3)-β-glucan synthase were analyzed. The (1,4)-β-glucan synthase activity was down-regulated by around 50% after light-treatment, the (1,4)-β-mannan synthase by around 85% and the galactose incorporating activity by around 80%. The decline of the (1,4)-β-glucan synthase, (1,4)-β-mannan synthase and the galactose incorporating activities after light exposure was gradual (half life of around 4 hours), suggesting that these enzyme activities are regulated at the transcriptional level of the corresponding genes. An attempt was made to correlate these activities with the expression and light-regulation of the maize Cellulose Synthase Like (ZmCSL) genes in the second centimeter of the mesocotyl. Many of the ZmCSLA and C genes but only a few of the ZmCSLD, E and F genes are expressed in the mesocotyl. Many but not all are light-regulated. For the ZmCSLA subfamily there is no correlation between light-regulation of transcript levels and enzymatic activities. The transcript levels of only three of the nine ZmCSLA genes expressed in the mesocotyl are strongly reduced after light-treatment, while the mannan synthase activity is reduced by around 85% after light-treatment.
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1 - Michigan State University, DOE Plant Research Laboratory
Keywords:
cell wall
transcriptional regulation
cellulose synthase like gene.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P17033
Abstract ID:1668 |
