Xyloglucan Endotransglycosylases Have a Function during the Formation of Secondary Cell Walls of Vascular Tissues
Open Access
- 26 November 2002
- journal article
- Published by Oxford University Press (OUP) in Plant Cell
- Vol. 14 (12), 3073-3088
- https://doi.org/10.1105/tpc.007773
Abstract
Xyloglucan transglycosylases (XETs) have been implicated in many aspects of cell wall biosynthesis, but their function in vascular tissues, in general, and in the formation of secondary walls, in particular, is less well understood. Using an in situ XET activity assay in poplar stems, we have demonstrated XET activity in xylem and phloem fibers at the stage of secondary wall formation. Immunolocalization of fucosylated xylogucan with CCRC-M1 antibodies showed that levels of this species increased at the border between the primary and secondary wall layers at the time of secondary wall deposition. Furthermore, one of the most abundant XET isoforms in secondary vascular tissues (PttXET16A) was cloned and immunolocalized to fibers at the stage of secondary wall formation. Together, these data strongly suggest that XET has a previously unreported role in restructuring primary walls at the time when secondary wall layers are deposited, probably creating and reinforcing the connections between the primary and secondary wall layers. We also observed that xylogucan is incorporated at a high level in the inner layer of nacreous walls of mature sieve tube elements.Keywords
This publication has 42 references indexed in Scilit:
- Characterization of a Tomato Xyloglucan Endotransglycosylase Gene That Is Down-Regulated by Auxin in Etiolated HypocotylsPlant Physiology, 2001
- The molecular basis of plant cell wall extensionPlant Molecular Biology, 2001
- Differential expression of cell-wall-related genes during the formation of tracheary elements in the Zinnia mesophyll cell systemPlant Molecular Biology, 2001
- Xyloglucan endotransglycosylase: evidence for the existence of a relatively stable glycosyl–enzyme intermediateBiochemical Journal, 1998
- Visualization of the cytoskeleton within the secondary vascular system of hardwood speciesJournal of Microscopy, 1997
- Changes in Levels of mRNAs for Cell Wall-Related Enzymes in Growing Cotton Fiber CellsPlant and Cell Physiology, 1997
- Arabidopsis TCH4, regulated by hormones and the environment, encodes a xyloglucan endotransglycosylase.Plant Cell, 1995
- The relationship between xyloglucan endotransglycosylase and in-vitro cell wall extension in cucumber hypocotylsPlanta, 1993
- Molecular cloning and characterization of genes expressed in shoot apical meristems.Plant Cell, 1991
- Genomic sequencing.Proceedings of the National Academy of Sciences, 1984