Immunogold localization of an extracellular β-1,3-glucanase of the ergot fungus Claviceps purpurea during infection of rye

摘要: Immunogold labelling and electron microscopy were used to investigate β-1,3-glucanase secretion by Claviceps purpurea during ergot disease of rye in situ. Molecular cytology allowed us explore the hypothesis that this enzyme might degrade host phloem callose maintain flow assimilates for fungal nutrition therefore could play a role pathogenicity. An extracellular endo-β-1,3-glucanase was purified from axenic culture an antibody raised. Enzyme activity staining immunoblotting showed monospecific present protein populations. Mycelia printings plate-grown cultures displayed spot-like streaky immuno-signals suggesting at hyphal tips young hyphae. The immuno gold localized predominantly cell walls mycelia culture. In Western blots honeydew fractions, one immunoreactive. inoculated plants, immunogold found all infection stages limited host-pathogen interface. Gold detected over protoplasts vacuoles tubularvesicular complexes multivesicular bodies, which fused with plasma membrane, indicating they are part pathway. secretory organelles lack any area apart interface verified origin immuno-detected infected ovaries. Antigenic sites located external, subcuticular, penetrating intercellular hyphae, secreted throughout colonization process planta. Intense regularly associated extended into adjacent walls, migration apoplast. periplasmic spaces reached deposition callose, pointing enzymatic suppression putative plant defense reactions. colonized inter- intracellularly. Hyphae penetrated pectic middle lamella sieve plates intense immuno-labelling supports unblocking hypothesis.