Phages, bacterial resistance and the plant environment (Powerpoint Presentation)

Phages, bacterial resistance & the plant environment

Alexander S. Roseasr204@ex.ac.uk

2014

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

Cellular warfare!LysisAdsorption

Surface receptors: flagella, pili, matrix

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

Thanks! Any questions?

Alexander S. Rose 16/02/14