Indirect penetration
- Wounds: Rhizopus , Aspergillus, Penicilium, Colletotrichum, etc. @ Rahul PC
- Natural opening:
a) Stomata: Puccina graminis tritici
b) Lenticels: Sclerotinia fructicola (Brown rot of fruits) , Streptomyces scabies (Potato scab).
c) Hydathodes: Xanthomonas campestris pv. Campestris (Black rot of crucifers).
Cell wall of pathogen
a) Middle lamella (made of pectin) : Lignin is found.
b) Primary wall (Made of cellulose, pectic substances): Primary constituents is hemicellulose.
c) Secondary wall: Entirely cellulose.