| Abstract Detail
Cell Walls Nadella, Ramya [1], Faik, Ahmed [2]. Bioinformatics, cloning and expression of putative xyloglucan biosynthetic genes from wheat and rice. Xyloglucans are the major hemicellulosic polysaccharides in the primary cell walls of dicots and non-graminaceous monocots but small amounts are also seen in the walls of grasses. They serve as cross-linkers of cellulose microfibrils to maintain the structural integrity of the cell wall. Xyloglucan consists of a β(1-4) linked glucose backbone substituted with xylosyl residues at C-6 position. Further substitution patterns vary depending on the species and tissues. Their biosynthesis mechanism is well understood in dicots where many biosynthetic genes have been identified, however this process is not well known in grasses. This study aims to identify the genes involved in xyloglucan biosynthesis in grasses, particularly the xylosyltransferases from wheat and rice, and to understand their functions. Wheat and rice homologs of Arabidopsis xyloglucan-xylosyltransferase (AtXT1, Faik et al., 2002) were identified using a bioinformatic script developed in our laboratory (Faik et al., 2006). The putative xylosyltransferases, TaXT1 and OsXT1, share 75% and 80% similarity to AtXT1, respectively. They are predicted to have a single transmembrane domain at the N-terminus region, which is a characteristic feature of type II glycosyltransferases located in the Golgi. In addition they also share several motifs conserved in all members of the glycosyltransferase 34 family. The cDNAs encoding TaXT1 and OsXT1 were cloned, and their expression in Pichia and Drosophila S2 expression systems is underway. The expressed proteins will be tested for their xylosyltransferase activity and biochemically characterized. Comparison of the requirements of these enzymes would be very informative and would help better understand xyloglucan biosynthesis.
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1 - Ohio University, Environmental and Plant Biology, 315 Porter Hall, Ohio University, Athens, Ohio, 45701, USA
2 - Ohio University, Environmental and Plant Biology
Keywords:
xyloglucan
Xylosyltransferases
grasses.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P17028
Abstract ID:1342 |
