The plant exocyst
Zhang, Y. ; Emons, A.M.C. ; Ketelaar, T. - \ 2010
Journal of Integrative Plant Biology 52 (2010)2. - ISSN 1672-9072 - p. 138 - 146.
electron tomographic analysis - s-receptor kinase - plasma-membrane - self-incompatibility - spatial regulation - cell polarity - saccharomyces-cerevisiae - arabidopsis-thaliana - tip growth - complex
exocyst is an octameric vesicle tethering complex that functions upstream of SNARE mediated exocytotic vesicle fusion with the plasma membrane. All proteins in the complex have been conserved during evolution, and genes that encode the exocyst subunits are present in the genomes of all plants investigated to date. Although the plant exocyst has not been studied in great detail, it is likely that the basic function of the exocyst in vesicle tethering is conserved. Nevertheless, genomic and genetic studies suggest that the exocyst complex in plants may have more diversified roles than that in budding yeast. In this review, we compare the knowledge about the exocyst in plant cells to the well-studied exocyst in budding yeast, in order to explore similarities and differences in expression and function between these organisms, both of which have walled cells
A xylogalacturonan epitope is specifically associated with plant cell detachment.
Willats, W.G.T. ; McCartney, L. ; Steele-King, C.G. ; Marcus, S.E. ; Mort, A.J. ; Huisman, M.M.H. ; Alebeek, G.J.W.M. van; Schols, H.A. ; Voragen, A.G.J. ; Goff, A. le; Bonnin, E. ; Thibault, J.F. ; Knox, J.P. - \ 2004
Planta 218 (2004)4. - ISSN 0032-0935 - p. 673 - 681.
pectic polysaccharides - spatial regulation - hairy regions - pea hulls - walls - homogalacturonan - tomato - cotyledons - separation - pericarp
A monoclonal antibody (LM8) was generated with specificity for xyloglacturonan (XGA) isolated from pea (Pisum sativum L.) testae. Characterization of the LM8 epitope indicates that it is a region of XGA that is highly substituted with xylose. Immunocytochemical analysis indicates that this epitope is restricted to loosely attached inner parenchyma cells at the inner face of the pea testa and does not occur in other cells of the testa. Elsewhere in the pea seedling, the LM8 epitope was found only in association with root cap cell development at the root apex. Furthermore, the LM8 epitope is specifically associated with root cap cells in a range of angiosperm species. In embryogenic carrot suspension cell cultures the epitope is abundant at the surface of cell walls of loosely attached cells in both induced and non-induced cultures. The LM8 epitope is the first cell wall epitope to be identified that is specifically associated with a plant cell separation process that results in complete cell detachment.