Plant Pathogenic Bacteria

Plant Pathogenic Bacteria

1. Taxonomy & Nomenclature

   • 6 main genera of free living pathogenic bacteria
     • Agrobacterium
       • Clavibacter & Curtobacterium
         • Erwinia
           • Pseudomonas
             • Xanthomonas
               • Streptomyces
   • Other
     • Xylem inhabiting fastidious bacteria
       • Phloem inhabiting fastidious bacteria
         • eg. Liberobacter
       • eg. Xylella

2. Bacterial nomenclature

3. Bacterial morphology

   • rods (except Streptomyces)
     • flagella (except Streptomyces & fastidious bacteria)
       • non spore forming
         • gram negative (except Clavibacter and Curtobacterium)

4. Growth requirements

   • aerobes (need oxygen)
     • need water
       • 25-30 degree celcius
         • mostly saprophytes
           • nectrotrophes

5. Bacterial Identification

   • pathogenicity & host symptoms
     • morphology
       • biochemical properties
         • genome sequence (eg. 16s RNA)

6. How Bacteria attack plants

   • produce extracellular compound
     • polysaccharides
       • enzymes
         • toxin
           • growth regulators
             • roles in pathogenicity
           • roles in pathogenicity
         • roles in pathogenicity
       • general properties
       • roles in pathogenicity

7. Summary of pathogenicity

8. Plant response to bacterial infection

   • Immune
     • Hypersensitive necrotic reaction
       • Susceptible necrotic reaction
         • susceptible non-necrotic reaction
           • galls
         • vascular wilts
         • soft rots

Images and files in the map