The structure and function of Erwinia chrysanthemi pectate lysase C, a plant virulence factor, is reviewed to illustrate one mechanism of pathogenesis at the molecular level. Current investigative topics are discussed in this paper.

1. The pectic substances of apple have been extracted and separated into a pure pectinic acid and a neutral arabinan-galactan complex by precipitation of the acidic component with ethanol and with cetylpyridinium chloride. 2. The composition of the fractions has been determined. The pectinic acid contained galacturonic acid, arabinose, galactose, rhamnose, xylose and several trace sugars. 3. Tr...

Changes in the composition and structure of cell walls and extracellular polysaccharides (ECP) were studied during the growth of suspension-cultured Arabidopsis thaliana microcalli. Three growth phases, namely the cell division phase, the cell expansion phase, and the stationary phase, were distinguished and associated with a decreasing cell cluster adhesion strength. Degradation of the homogal...

The changes of microorganisms and pectic substances of partially processed carrots (PPC) were determined with respect to cutting direction. The increase of microbial counts occurred in all tissues and both lengthwise cut sections (LCS)and crosswise cut sections (CCS). The microbial count in the xylem of LCS increased at a greater rate than those of phloem at 20•Ž. The counts in both tissues of ...

Kinetin and CaCl(2), in the presence of indoleacetic acid, promoted lateral expansion of epicotyls of decapitated and derooted Alaska pea seedlings (Pisum sativum L.) and inhibited their elongation. This growth response was correlated with the development of cell walls unusually rich in pectic uronic acids. Epicotyls in calcium-auxin solutions continued to enlarge and to add new wall material l...

The partial purification and characterization of cell wall polysaccharides isolated from suspension-cultured Douglas fir (Pseudotsuga menziesii) cells are described. Extraction of isolated cell walls with 1.0 m LiCl solubilized pectic polysaccharides with glycosyl-linkage compositions similar to those of rhamnogalacturonans I and II, pectic polysaccharides isolated from walls of suspension-cult...

The aim of this work was to investigate heat-induced changes in cell wall polysaccharides of carrot in relation to texture. Discs of fresh carrot (Daucus carota cv Amstrong) tissue were subjected to cooking (100¡C, 20 min), with or without a pre-cooking treatment (50¡C, 30 min). Alcohol-insoluble residues were prepared from the tissues and were extracted sequentially with water, NaCl, CDTA, and...