Using pathogen effectors to investigate host resistance mechanisms

JONATHAN DG JONES; ERIC KEMEN; KEE-HOON SOHN; GEORGINA FABRO; JORGE BADEL; SOPHIE PIQUEREZ

Versailles, France

Simposio; 22nd New Phytologist Symposium; 2009

Revista New Phytologist

Plant pathogens use small molecules and also proteins to render their hosts susceptible. Many bacteria and other pathogens use a specialized secretion system to deliver proteins into host cells that interfere with host defence. We have taken advantage of the bacterial type III secretion system (T3SS) to investigate effectors from filamentous pathogens such as oomycetes. We are using T3SS delivery of oomycete effectors from Pseudomonas sp to investigate the effector complement of the downy mildew pathogen Hyaloperonospora parasitica (Hpa). I will report recent data on Hpa effector functions and on the use of the Solexa/Illumina sequencing instrument to advance our understanding of Hpa pathogenicity. We are using Illumina paired read sequencing and Velvet software (Zerbino and Birney, Genome Research, 2008) to assemble sequences of multiple races of another oomycete pathogen, Albugo candida, which is particularly effective at shutting down host defence. The analysis of its effectors is likely to provide very interesting new insights into host defence mechanisms. In addition, we are using T3SS delivery of oomycete effectors to investigate the molecular basis of pathogen/host specificity and non-host resistance. An update on recent progress will be presented.