Cell death inducing activity of the Phytophthora capsici effector CRN83_152 can be uncoupled from its virulence function(s)
T. AMARO (1), G. Thilliez (1), R. McLeod (1), E. Huitema (2) (1) Division of Plant Sciences, University of Dundee, United Kingdom; (2) Division of Plant Sciences, University of Dundee, United Kingdom

Phytophthora species form a devastating group of Plant-pathogenic oomycetes that hamper crop production worldwide. Pathogens must perturb host immune systems, a feat which is achieved through the secretion of molecules (effectors) that target host immune signalling processes and dampen defence responses. Most plant pathogenic oomycetes carry a family of effector coding genes that were named after their ability to cause Crinkling and Necrosis (CRN). Importantly, CRN effectors are known to contribute to virulence, leading to the question as to whether cell death induction is a virulence function. Previously, we have identified CRN83_152 from Phytophthora capsici as a cell death inducer in plants, able to enhance P. capsici virulence. To ask whether cell death is linked to virulence function, we generated a library of CRN83_152 mutants by mutagenic PCR and screened for “no cell death” (NCD) variants. This led to the identification of 85 NCD mutants, from which 9 were selected for further analysis and appeared stable in planta. Over-expression and subsequent P. capsici infection revealed that some but not all NCD mutants retained virulence function in our assays. These results suggest that CRN-induced cell death can be uncoupled from virulence function, and raises questions on the relevance of cell death. We will present this data along with results from further functional studies that are on going and may shed light on the functions of this relatively conserved effector family.

Abstract Number: P9-237
Session Type: Poster