Defence and signalling in Potato-Phytophthora infestans interactions
Author
Summary, in English
Potato is one of the major food crops and its yield is severely affected by late blight disease caused by
Phytophthora infestans. P. infestans has the ability to manipulate plant defence signalling by secreting effector
molecules causing so called effector triggered susceptibility. Some plants can recognize these effectors via
resistance proteins that reactivate plant defence and lead to effector triggered immunity. This thesis discusses
identification and analysis of field-pathological relevant potato material for resistance against P. infestans. The
two selected potato clones were shown to be resistant, in fields with diverse P.infestans populations, and in
growth chambers with a highly virulent Swedish P.infestans strain. They have slightly different resistance
reaction at phenotypic and molecular level. One of the two resistant potato clones (SW93-1015) showed an
unusual reduction in hypersensitive reaction expansion and part of the induced defence system was
constitutively expressed in this potato clone. These two resistant potato clones and the susceptible cultivar
Desiree were studied by a combination of quantitative proteomics assisted with newly generated sequence data,
and genome wide transcriptomics. A number of putative effector-targets in the potato secretome, often single
members of large gene families were identified. These studies have also provided us with insight to
components involved in successful plant defence amid hypersensitive response. By analysing crossing
populations, a remarkably simple genetic resistance in the potato clone SW93-1015 was identified. We also
present a primary global phosphoproteomics analysis that led to identification of novel phosphosites and
phosphorylation of several P. infestans effectors. These findings lead us to a better understanding of plant
pathogen interactions in field relevant systems and hopefully will allow us to create more tools to overcome
this devastating crop disease.
Phytophthora infestans. P. infestans has the ability to manipulate plant defence signalling by secreting effector
molecules causing so called effector triggered susceptibility. Some plants can recognize these effectors via
resistance proteins that reactivate plant defence and lead to effector triggered immunity. This thesis discusses
identification and analysis of field-pathological relevant potato material for resistance against P. infestans. The
two selected potato clones were shown to be resistant, in fields with diverse P.infestans populations, and in
growth chambers with a highly virulent Swedish P.infestans strain. They have slightly different resistance
reaction at phenotypic and molecular level. One of the two resistant potato clones (SW93-1015) showed an
unusual reduction in hypersensitive reaction expansion and part of the induced defence system was
constitutively expressed in this potato clone. These two resistant potato clones and the susceptible cultivar
Desiree were studied by a combination of quantitative proteomics assisted with newly generated sequence data,
and genome wide transcriptomics. A number of putative effector-targets in the potato secretome, often single
members of large gene families were identified. These studies have also provided us with insight to
components involved in successful plant defence amid hypersensitive response. By analysing crossing
populations, a remarkably simple genetic resistance in the potato clone SW93-1015 was identified. We also
present a primary global phosphoproteomics analysis that led to identification of novel phosphosites and
phosphorylation of several P. infestans effectors. These findings lead us to a better understanding of plant
pathogen interactions in field relevant systems and hopefully will allow us to create more tools to overcome
this devastating crop disease.
Department/s
Publishing year
2012
Language
English
Document type
Dissertation
Publisher
Department of Biology, Lund University
Topic
- Biological Sciences
Keywords
- Phytophthora infestans
- Plant defence
- hypersensitive response
- resistance
- susceptibility
Status
Published
Research group
- Cell and organism biology
Supervisor
- Erik Andreasson
ISBN/ISSN/Other
- ISBN: 978-91-7473-404-1
Defence date
30 November 2012
Defence time
09:30
Defence place
Blue hall, Ecology Builiding.
Opponent
- Sabine Rosahl (Dr)