In Planta Effector Competition Assays Detect Hyaloperonospora arabidopsidis Effectors That Contribute to Virulence and Localize to Different Plant Subcellular Compartments

JORGE L. BADEL; DAVID GREENSHIELDS; SOPHIE J.M. PIQUEREZ; GANASHYAM RALLAPALLI; GEORGINA FABRO; NAVEED ISHAQUE; JONATHAN D. G. JONES

AMER PHYTOPATHOLOGICAL SOC

Lugar: St. Paul, Minessota; Año: 2013 vol. 26 p. 745 - 745

he genome of the pathogenic oomycete Hyaloperonospora arabidopsidis is predicted to encode at least 134 high-confidence effectors (HaRxL) carrying the RxLR motif implicated in their translocation into plant cells. However, only four avirulence genes (ATR1, ATR13, ATR5, and ATR39) have been isolated. This indicates that identification of HaRxL effectors based on avirulence is low throughput. We aimed at rapidly identifying H. arabidopsidis effectors that contribute to virulence by developing methods to detect and quantify multiple candidates in bacterial mixed infections using either Illumina sequencing or capillary electrophoresis. In these assays, referred to here as in planta effector competition assays, we estimate the contribution to virulence of individual effectors by calculating the abundance of each HaRxL in the bacterial population recovered from leaves 3 days after inoculation relative to abundance in the initial mixed inoculum. We identified HaRxL that enhance Pseudomonas s