SseF, a type III effector protein from the mammalian pathogen Salmonella enterica, requires resistance-gene-mediated signalling to activate cell death in the model plant Nicotiana benthamiana
Article first published online: 4 APR 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 194, Issue 4, pages 1046–1060, June 2012
How to Cite
Üstün, Ş., Müller, P., Palmisano, R., Hensel, M. and Börnke, F. (2012), SseF, a type III effector protein from the mammalian pathogen Salmonella enterica, requires resistance-gene-mediated signalling to activate cell death in the model plant Nicotiana benthamiana. New Phytologist, 194: 1046–1060. doi: 10.1111/j.1469-8137.2012.04124.x
- Issue published online: 2 MAY 2012
- Article first published online: 4 APR 2012
- Received: 19 December 2011, Accepted: 10 February 2012
- hypersensitive response (HR);
- plant–bacteria interaction;
- R protein;
- type III effector protein (T3E)
- •Type III effector proteins (T3Es) of many Gram-negative pathogenic bacteria manipulate highly conserved cellular processes, indicating conservation in virulence mechanisms during the infection of hosts of divergent evolutionary origin.
- •In order to identify conserved effector functions, we used a cross-kingdom approach in which we expressed selected T3Es from the mammalian pathogen Salmonella enterica in leaves of Nicotiana benthamiana and searched for possible virulence or avirulence phenotypes.
- •We show that the T3E SseF of S. enterica triggers hypersensitive response (HR)-like symptoms, a hallmark of effector-triggered immunity in plants, either when transiently expressed in leaves of N. benthamiana by Agrobacterium tumefaciens infiltration or when delivered by Xanthomonas campestris pv vesicatoria (Xcv) through the type III secretion system. The ability of SseF to elicit HR-like symptoms was lost upon silencing of suppressor of G2 allele of skp1 (SGT1), indicating that the S. enterica T3E is probably recognized by an R protein in N. benthamiana. Xcv translocating an AvrRpt2–SseF fusion protein was restricted in multiplication within leaves of N. benthamiana. Bacterial growth was not impaired but symptom development was rather accelerated in a compatible interaction with susceptible pepper (Capsicum annuum) plants.
- •We conclude that the S. enterica T3E SseF is probably recognized by the plant immune system in N. benthamiana, resulting in effector-triggered immunity.