Use this URL to cite or link to this record in EThOS:
Title: Investigating the role of the exocyst complex in infection-related development of the rice blast fungus Magnaporthe oryzae
Author: Gupta, Yogesh Kumar
ISNI:       0000 0004 5354 3332
Awarding Body: University of Exeter
Current Institution: University of Exeter
Date of Award: 2014
Availability of Full Text:
Access from EThOS:
Access from Institution:
Host colonization is mediated through the secretion of effector proteins in order to neutralize host immune responses. However, the mechanism of the effector delivery during biotrophic invasion is not well defined in M. oryzae. In this thesis, I define the role of the exocyst complex, an evolutionarily conserved octameric protein complex involved in vesicle docking to the plasma membrane (composed of Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70 and Exo84), during infection-related development in M. oryzae. Like other filamentous fungi, M. oryzae, exocyst components localize to the vegetative hyphal tip distinct from the Spitzenkörper. However, at the initial stage of infection-related development all the exocyst components localise as a ring at the cortex of the appressorium and re-assembles around the appressorium pore in an actin-dependent manner in mature appressoria. I report that the septin network is required for the transition of exocyst ring from periphery to the appressorium pore. Deletion of Exo70 and Sec5 showed significant reduction in protein secretion and plant infection. I show that Sec6 is required for the exocyst assembly around the appressorium pore and effector secretion from the appressorium. I report that, during biotrophic invasion, effectors are secreted through a distinct pathway. Apoplastic effectors, Bas4 and Slp1 are secreted via a Golgi-dependent pathway while secretion of cytoplasmic effectors, Pwl2 and Bas1 meditates through a Golgi-independent pathway in which exocyst components Exo70 and Sec5 are involved.
Supervisor: Talbot, Nicholas J. Sponsor: Halpin Scholarship for Rice Blast Research
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Exocyst ; Magnaporthe oryzae ; Rice ; Septins ; Effector secretion