Details

Autor(en) / Beteiligte

• Giesbers, Anne K. J.
• Pelgrom, Alexandra J. E.
• Visser, Richard G. F.
• Niks, Rients E.
• Van den Ackerveken, Guido
• Jeuken, Marieke J. W.

Titel

Effector-mediated discovery of a novel resistance gene against Bremia lactucae in a nonhost lettuce species

Ist Teil von

• The New phytologist, 2017-11, Vol.216 (3), p.915-926

Ort / Verlag

England: New Phytologist Trust

Erscheinungsjahr

2017

Quelle

Access via Wiley Online Library

Beschreibungen/Notizen

• Candidate effectors from lettuce downy mildew (Bremia lactucae) enable high-throughput germplasm screening for the presence of resistance (R) genes. The nonhost species Lactuca saligna comprises a source of B. lactucae R genes that has hardly been exploited in lettuce breeding. Its cross-compatibility with the host species L. sativa enables the study of inheritance of nonhost resistance (NHR). We performed transient expression of candidate RXLR effector genes from B. lactucae in a diverse Lactuca germplasm set. Responses to two candidate effectors (BLR31 and BLN08) were genetically mapped and tested for co-segregation with disease resistance. BLN08 induced a hypersensitive response (HR) in 55% of the L. saligna accessions, but responsiveness did not co-segregate with resistance to Bl:24. BLR31 triggered an HR in 5% of the L. saligna accessions, and revealed a novel R gene providing complete B. lactucae race Bl:24 resistance. Resistant hybrid plants that were BLR31 nonresponsive indicated other unlinked R genes and/or nonhost QTLs. We have identified a candidate avirulence effector of B. lactucae (BLR31) and its cognate R gene in L. saligna. Concurrently, our results suggest that R genes are not required for NHR of L. saligna.