Decreased abundance of type III secretion system-inducing signals in Arabidopsis mkp1 enhances resistance against Pseudomonas syringae
Many phytopathogenic bacteria use a type III secretion system (T3SS) to inject defense-suppressing effector proteins into host cells. Genes encoding the T3SS are induced at the start of infection, yet host signals that initiate T3SS gene expression are poorly understood. Here we identify several plant-derived metabolites that induce the T3SS in the bacterial pathogen Pseudomonas syringae pv tomato DC3000. In addition, we report that mkp1 (mapk phosphatase 1), an Arabidopsis mutant that is more resistant to bacterial infection, produces decreased levels of these T3SS-inducing metabolites. Consistent with the observed decrease in these metabolites, T3SS effector delivery by DC3000 was impaired in mkp1. Addition of the bioactive metabolites to the mkp1-DC3000 interaction fully restored T3SS effector delivery and suppressed enhanced resistance in mkp1. Together, these results demonstrate that DC3000 perceives multiple signals derived from plants to initiate their virulence program, and reveal a new layer of molecular communication between plants and these pathogenic bacteria.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1134508
- Report Number(s):
- PNNL-SA-97264; 47395; KP1704020
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, 111(18):6846-6851, Journal Name: Proceedings of the National Academy of Sciences of the United States of America, 111(18):6846-6851
- Country of Publication:
- United States
- Language:
- English
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