Mechanism of infection - Pathogenesis Development of Haustorium and Appresorium

1. Mrs. P. SATHIYAVANI, M.SC., M.Phil., B.Ed., SET, Ph.D
ASSISTANT PROFESSOR
DEPARTMENT OF BOTANY
BON SECOURS COLLEGE FOR WOMEN, THANJAVUR

3. MECHANISM OF
INFECTION
* Pathogenesis
* Infection
* Penetration of pathogen
* Phases of penetration
* Infection structures

4. WHAT IS PATHOGENESIS?
•The process or chain of events whereby
disease development takes place.
•Process of infection or the actual way in
which the disease develops in plant body(
host )
•Pathos – disease, genesis- development

5. THREE PHASES OF THE PENETRATION
OF THE PATHOGEN
* Pre – Penetration Change
* Penetration process
* Post - penetration

6. •Pre –penetration spore
germination
•Penetration entry of the pathogen
into the host( Development of infection
structures)
•Post – penetration colonization of
z
z
z

7. THE MECHANISM OF INFECTION
Infection structures
•Germ tube
•Appresorium
•Infection hyphae
•Haustoria

8. DEVELOPMENT OF APPRESSORIUM AND
HAUSTORIUM

9. MECHANISM OF HAUSTORIUM
DEVELOPMENT
Germinationof Spore
Formationof germtube
Appresoria
Penetrationof Peg
Infectionof Hyphae
Haustoria

10. Results of haustoria penetration into host cells
• Fungi that do not kill their hosts utilize
specialized feeding structure called
Haustoria. These structures are formed
from a hyphae tip that penetrates into host
cell and forms a union with the plant’s
plasma membrane which serves as the site
for the uptake of nutrients.
• This constant drain of nutrients results in
yield losses, discoloration and are visibly
stunted in their growth.

11. We are
fun-
guys!
Thank you all