Skip to Main content Skip to Navigation
Journal articles

Naturally occurring nonpathogenic isolates of the plant pathogen species Pseudomonas syringae lack a type III secretion system and effector gene orthologues

Abstract : Pseudomonas syringae causes plant diseases, and the main virulence mechanism is a type III secretion system (T3SS) that translocates dozens of effector proteins into plant cells. Here we report the existence of a subgroup of P. syringae isolates that do not cause disease on any plant species tested. This group is monophyletic and most likely evolved from a pathogenic P. syringae ancestor through loss of the T3SS. In the nonpathogenic isolate P. syringae 508 the genomic region that in pathogenic P. syringae strains contains the hrp-hrc cluster coding for the T3SS and flanking effector genes is absent. P. syringae 508 was also surveyed for the presence of effector orthologues from the closely related pathogenic strain P. syringae pv. syringae B728a, but none were detected. The absence of the hrp-hrc cluster and effector orthologues was confirmed for other nonpathogenic isolates. Using the AvrRpt2 effector as reporter revealed the inability of P. syringae 508 to translocate effectors into plant cells. Adding a plasmid-encoded T3SS and the P. syringae pv. syringae 61 effector gene hopA1 increased in planta growth almost 10-fold. This suggests that P. syringae 508 supplemented with a T3SS could be used to determine functions of individual effectors in the context of a plant infection, avoiding the confounding effect of other effectors with similar functions present in effector mutants of pathogenic isolates
Complete list of metadata

Cited literature [66 references]  Display  Hide  Download

https://hal.inrae.fr/hal-02666849
Contributor : Migration Prodinra <>
Submitted on : Sunday, May 31, 2020 - 9:28:23 AM
Last modification on : Friday, February 5, 2021 - 4:10:15 AM

File

2008-Mohr-journal of bacteriol...
Publisher files allowed on an open archive

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Collections

Citation

Toni J. Mohr, Haijie Liu, Shuangchun Yan, Cindy E. Morris, José A. Castillo, et al.. Naturally occurring nonpathogenic isolates of the plant pathogen species Pseudomonas syringae lack a type III secretion system and effector gene orthologues. Journal of Bacteriology, American Society for Microbiology, 2008, 190 (8), pp.2858-2870. ⟨10.1128/JB.01757-07⟩. ⟨hal-02666849⟩

Share

Metrics

Record views

42

Files downloads

68