Comparative localization of three classes of cell wall proteins

Abstract

The localization of the cell wall proline-rich proteins (PRPs), and the gene expression of the cell wall glycine-rich proteins (GRPs) and the hydroxyproline-rich glycoproteins (HRGPs) were examined in several dicot species. The PRPs are accumulated in the corner walls of the cortex where several cells are joined together and in the protoxylem cell walls of 3-day-old soybean root. In 1-month-old soybean plants, the PRPs are specifically deposited in xylem vessel elements of the young stem, and they are accumulated in both phloem fibers and xylem vessel elements and fibers of the older stem. Likewise, the PRPs are localized in xylem vessel elements and fibers in tomato, petunia, potato and tobacco stems. They are also found in outer and inner phloem fiber cell walls of tomato stem and in outer phloem fiber cell walls of petunia stem. The gene expression of the HRGPs and the GRPs is developmentally regulated in tomato, petunia and tobacco stems. HRGP mRNAs are abundant in outer and inner phloem regions, while GRP mRNAs are present mostly in primary xylem and in the cambium region. Immunocytochemical localization showed that the GRPs have a localization pattern similar to that of the PRPs in tomato, petunia and tobacco stems.

Early Transcriptome Analyses of Z-3-Hexenol-Treated Zea mays Revealed Distinct Transcriptional Networks and Anti-Herbivore Defense Potential of Green Leaf Volatiles

“…Proline-rich proteins are often secreted into the cell wall and can become cross-linked through reactive oxygen species by peroxidases thereby providing further stability to the cell wall [52-54]. Furthermore, they may serve as a scaffold for lignin depositions [55]. Both processes may be closely linked and as such may provide the damaged or neighboring cells with the means to maintain their structural integrity.…”

Structural models of primary cell walls in flowering plants: consistency of molecular structure with the physical properties of the walls during growth

“…In some instances, genes have been cloned whose open reading frames predict structural roles for their products once inserted in the cell wall (Condit and Meagher, 1986). Tissue printing has shown cell and tissue specific location of hydroxyproline-rich glycoproteins (HRGPs) (Cassab and Varner, 1987;Hood et a/., 1991;Keller eta/., 1989;Ye and Varner, 1991). Sequences have been deduced for several of these proteins, and their sites of glycosylation and other post-translational alterations are being studied to give clues to the three-dimensional conformation and chemistry of these glycoproteins.…”

“…The data on appearance of extensins and their relationship to growth do not support this view. Extensin precursors can be seen very early in cell wall formation, even in walls of cells near the meristem (Ye and Varner, 1991), but a large increase in amount of extensin in the cell wall is associated with cessation of growth (Sadava et al, 1973). In some cells, a strong correlation is found between final cell length and amount of Hyp in the cell walls (Iraki etal., 1989c), whereas the correlation is not as obvious in other systems (Ye and Vamer, 1991).…”

“…Like extensin, the cell wall GRP is recalci-trant to extraction, but antibodies have been raised against artificial peptides corresponding to hydrophilic regions outside of the pleated sheet. These antibodies localize the GRP precursors to protoxylern elements and other cells that eventually become lignified (Condit eta/., 1990;Keller et a/., 1989;Ye and Varner, 1991;Ye eta/., 1991). The GRP is wound-inducible (Condit and Meagher, 1987), but this protein and others may function in wound-induced xylogenesis rather than as a response to pathogen invasion.…”

Developmental expression and biochemical analysis of the Arabidopsis atao1 gene encoding an H2O2‐generating diamine oxidase

“…This suggests that ATAO1 could supply H 2 O 2 both for structural protein cross-linking and lignification during vascular differentiation as has been proposed for amine oxidases in other plants based on histochemical and immunological staining profiles (Angelini and Federico, 1989;Federico and Angelini, 1991). As plant vascular tissue develops, there is association of various structural proteins including the hydroxyproline-rich glycoproteins (HRGPs), glycine-rich proteins (GRPs) and proline-rich proteins (PRPs) with cells that are to become lignified (Jose and Puigdomenech, 1993;Keller et al, 1989;Ye et al, 1991). GRPs and PRPs are expressed in a tissue-specific manner, with the highest expression levels occurring in primary xylem and phloem cells (Ye et al, 1991), and GRPs have been implicated in providing a cross-linked framework for the subsequent deposition of lignin in vascular tissue (Keller et al, 1989).…”