Scope•Viruses of prokaryotes
- Everywhere
•Complex interactions
- Phage-Bacteria-Plant
•Phage therapy- Biocontrol (Jones 2012)
Considerations for using bacteriophages for plant disease control (2012) Bacteriophage.2(4):208-214.
OutlineWhat role do phages play in mediating
plant- pathogen interactions?
Phageecolog
yResistance
Lifehistory
Hostdefence
Method
H1
Relevance, application
Plant environment
Host resistance
Fig.1 Bacteriophage resistance mechanisms (2010) S. J. Labrie, J. E. Samson & S. Moineau. Nature Reviews Microbiology 8, 317-327
(Labrie et al 2010)
a b c
Mechanisms to prevent adsorption
Plant defence•Microbe-associated molecular patterns (MAMP)
Van Wees, S., Van der Ent, S., & Pieterse, C. M. (2008). Plant immune responses triggered by beneficial microbes. Current opinion in plant biology,11(4), 443-448.
Trigger systemic immunity (Van Wees et al
2008)
Interaction?
+ Environment can alter host-parasite interactions
(Wolinska & King 2009)
PHAGE-mediated
resistance
BACTERIA
surface
receptors PLANT
immune response
Wolinska, J., & King, K. C. (2009). Environment can alter selection in host–parasite interactions. Trends in parasitology, 25(5), 236-244.
Phenotypemediat
ed selection
bioticabioti
c
Δ
~~~ As a function of ~~~
Δ
Q: How does host resistance change?
(Phage Φ6)
(Pseudomonas syringae p.v. “tomato”)
(Solanum lycopersicum)
Genotype
Experimental evolutionInoculate with P.
syringae
Apply phage over time
Assay resistan
ce
• Rate• Fitness
• Costs• Loci
In vivo
In vitro
Vs.
HypothesisH1: Manipulating biotic and abiotic
factors of the S. lycopersicum plant environment will cause different
responses in P. syringae resistance to phage
Variables?
LightBiot
icAbiotic
Priming Humidity
PathovarPhage mix(Koskella 2011)
Koskella, B., Lin, D. M., Buckling, A., & Thompson, J. N. (2012). The costs of evolving resistance in
heterogeneous parasite environments Proc. Roy.Soc. B: Biological Sciences, 279(1735), 1896-1903.
Priming prepares progeny
Luna, E. et al. Next-generatrion systemic acquired resistance
Plant Physiol. 2011;158:844-853
Molinier, J., Ries, G., Zipfel, C., & Hohn, B. (2006). Transgeneration memory of stressin plants. Nature, 442(7106), 1046-1049.
Hrs post-SA treatment
(Molinier et al 2006) (Luna et al 2011)
1A
1B
2A
2B
F1
Parent
SummaryMany receptors on pathogen cell surface
key:- Phage infection
and/or- Bacterial virulence
Experimentally evolve P. syringae : phage * plant
Local biotic & abiotic plant environment may shape resistance genotype/phenotype
alongside phage
Plant disease•Predict & manage
e.g. Bleeding canker (horse chesnut)
Crop losses
•‘Phage therapy’
Antibiotic alternative