Ultrastructure of interactions between pseudomonads and oat leaves

摘要: Abstract Ultrastructural studies were made on interactions between oat leaves and the compatible pathogen Pseudomonas coronafaciens incompatible bacteria P. var. atropurpurea, fluorescens tabaci . Ruthenium red, a cytochemical stain for acidic polysaccharides, was used to enhance resolution of bacterial extracellular polysaccharide (EPS) in vivo EPS accumulation attachment cell walls assessed quantitatively. Two types association distinguished, (1) encapsulation by fibrillar materials smooth areas plant wall (physical entrapment) (2) involving localized but pronounced modification (often degradation) underlying wall. Quantitative analyses showed that accumulated rapidly around not bacteria. Production appeared prevent walls. The proportion attached increased 2·5 12 h after inoculation, only with more than 35% associated modifications. Our results suggest per se is unlikely restrict multiplication oats may allow transfer factors causing production antibacterial compounds challenged cells. Examination tobacco gave closely comparable those recorded oats. bacterium, this case, , surrounded whereas not, often