Multiple candidate effectors from the oomycete pathogen Hyaloperonospora arabidopsidis suppress host plant immunity

GEORGINA FABRO; JENS STEINBRENNER; MARY COATES; NAVEED ISHAQUE; LAURA BAXTER; DAVID J. STUDHOLME; EVELYN KÖRNER; REBECCA L. ALLEN; SOPHIE J.M. PIQUEREZ; ALEJANDRA ROUGON-CARDOSO; DAVID GREENSHIELDS; RITA LEI; JORGE L. BADEL; MARIE-CECILE CAILLAUD; KEE-HOON SOHN; GUIDO VAN DEN ACKERVEKEN; JANE E. PARKER; JIM BEYNON; JONATHAN D. G. JONES

PUBLIC LIBRARY SCIENCE

Lugar: Notre Dame Indiana USA; Año: 2011

omycete pathogens cause diverse plant diseases. To successfully colonize their hosts, they deliver a suite of effector proteins that can attenuate plant defenses. In the oomycete downy mildews, effectors carry a signal peptide and an RxLR motif. Hyaloperonospora arabidopsidis (Hpa) causes downy mildew on the model plant Arabidopsis thaliana (Arabidopsis). We investigated if candidate effectors predicted in the genome sequence of Hpa isolate Emoy2 (HaRxLs) were able to manipulate host defenses in different Arabidopsis accessions. We developed a rapid and sensitive screening method to test HaRxLs by delivering them via the bacterial type three secretion system (TTSS) of Pseudomonas syringae pv tomato DC3000-LUX (Pst-LUX) and assessing changes in Pst-LUX growth in planta on 12 Arabidopsisaccessions, The majority (~ 70%) of the 64 candidates tested positively contributed to Pst-LUX growth on more than one accession indicating that Hpa virulence likely involves multiple effectors with wea