Distribution of Fucose-Containing Xyloglucans in Cell Walls of the mur1 Mutant of Arabidopsis

Abstract

The monoclonal antibody, CCRC-M1, which recognizes a fucose (Fuc)-containing epitope found principally in the cell wall polysaccharide xyloglucan, was used to determine the distribution of this epitope throughout the mur1 mutant of Arabidopsis. Immunofluorescent labeling of whole seedlings revealed that mur1 root hairs are stained heavily by CCRC-M1, whereas the body of the root remains unstained or only lightly stained. Immunogold labeling showed that CCRC-M1 labeling within themur1 root is specific to particular cell walls and cell types. CCRC-M1 labels all cell walls at the apex of primary roots 2 d and older and the apices of mature lateral roots, but does not bind to cell walls in lateral root initials. Labeling with CCRC-M1 decreases in mur1 root cells that are undergoing rapid elongation growth such that, in the mature portions of primary and lateral roots, only the walls of pericycle cells and the outer walls of epidermal cells are labeled. Growth of the mutant on Fuc-containing media restores wild-type labeling, where all cell walls are labeled by the CCRC-M1 antibody. No labeling was observed in mur1hypocotyls, shoots, or leaves; stipules are labeled. CCRC-M1 does label pollen grains within anthers and pollen tube walls. These results suggest the Fuc destined for incorporation into xyloglucan is synthesized using one or the other or both isoforms of GDP-d-mannose 4,6-dehydratase, depending on the cell type and/or developmental state of the cell.

The intercellular biotrophic leaf pathogen Cymadothea trifolii locally degrades pectins, but not cellulose or xyloglucan in cell walls of Trifolium repens

“…A problem of immunolocalization of cell wall antigens is their frequently uneven distribution. Several authors have pointed out that some plant cell wall components are probably present in discrete domains (Lynch & Staehelin, 1992;Freshour et al, 1996;Freshour et al, 2003). Such incoherence makes it difficult to provide definite evidence for a cell wall area as small as 300 -400 nm, the diameter of the tube.…”

Quantitative Evaluation of Hybrid Aspen Xylem and Immunolabeling Patterns Using Image Analysis and Multivariate Statistics

“…Control samples were labeled in parallel with omission of the primary antibody. (Puhlmann et al 1994;Freshour et al 2003;Pattathil et al 2010). b Centre for Plant Sciences, Univ.…”

TheArabidopsis irregular xylem8Mutant Is Deficient in Glucuronoxylan and Homogalacturonan, Which Are Essential for Secondary Cell Wall Integrity

“…Immunolocalizations (immunofluorescence and immunogold) were performed as described (Freshour et al, 1996(Freshour et al, , 2003. Immunofluorescence images were captured using a Nikon DS-L1 camera control unit and a DS-5M camera head mounted on the microscope.…”

“…Tissues harvested from 7-week-old plants grown in soil (Freshour et al, 2003) were transferred directly to fixative (1.6% [v/v] paraformaldehyde and 0.2% [w/v] glutaraldehyde in 25 mM sodium phosphate, pH 7.1, containing 0.02% [v/v] Triton X-100). Subsequent fixation and embedding of the tissue was performed as described (Freshour et al, 1996) except that infiltration of resin was performed using only one intermediate step of 50% (v/v) LR White resin:ethanol followed by three incubations with 100% LR White, all for 24 h each.…”