20971913
not annotated - annotated - LINNAEUS only
Structural and functional analysis of the type III secretion system from Pseudomonas fluorescens Q8r1-96.
Pseudomonas fluorescens Q8r1-96 represents a group of rhizosphere strains responsible for the suppressiveness of agricultural soils to take-all disease of wheat. It produces the antibiotic 2,4-diacetylphloroglucinol and aggressively colonizes the roots of cereal crops. In this study, we analyzed the genome of Q8r1-96 and identified a type III protein secretion system (T3SS) gene cluster that has overall organization similar to that of the T3SS gene cluster of the plant pathogen Pseudomonas syringae. We also screened a collection of 30 closely related P. fluorescens strains and detected the T3SS genes in all but one of them. The Q8r1-96 genome contained ropAA and ropM type III effector genes, which are orthologs of the P. syringae effector genes hopAA1-1 and hopM1, as well as a novel type III effector gene designated ropB. These type III effector genes encoded proteins that were secreted in culture and injected into plant cells by both P. syringae and Q8r1-96 T3SSs. The Q8r1-96 T3SS was expressed in the rhizosphere, but mutants lacking a functional T3SS were not altered in their rhizosphere competence. The Q8r1-96 type III effectors RopAA, RopB, and RopM were capable of suppressing the hypersensitive response and production of reactive oxygen species, two plant immune responses.
Ann file
T1 Species 73 104 Pseudomonas fluorescens Q8r1-96
N1 Reference T1 Taxonomy:294
T2 Species 108 139 Pseudomonas fluorescens Q8r1-96
N2 Reference T2 Taxonomy:294
T3 Species 419 426 Q8r1-96
N3 Reference T3 Taxonomy:294
T4 Species 591 611 Pseudomonas syringae
N4 Reference T4 Taxonomy:317
T5 Species 665 679 P. fluorescens
N5 Reference T5 Taxonomy:294
T6 Species 744 751 Q8r1-96
N6 Reference T6 Taxonomy:294
T7 Species 836 847 P. syringae
N7 Reference T7 Taxonomy:317
T8 Species 1057 1068 P. syringae
N8 Reference T8 Taxonomy:317
T9 Species 1073 1080 Q8r1-96
N9 Reference T9 Taxonomy:294
T10 Species 1092 1099 Q8r1-96
N10 Reference T10 Taxonomy:294
T11 Species 1231 1238 Q8r1-96
N11 Reference T11 Taxonomy:294
T12 Species 263 268 wheat
N12 Reference T12 Taxonomy:4565 Triticum aestivum