Prediction, structure characterization, and evolutionary analysis of Erwinia psidii putative type III effectors

AbstractHost-specific legume-rhizobium symbiosis is strictly controlled by rhizobial type III effectors (T3Es) in some cases. Here, we demonstrated that the symbiosis of Vigna radiata (mung bean) with Bradyrhizobium diazoefficiens USDA110 is determined by NopE, and this symbiosis is highly dependent on host genotype. NopE specifically triggered incompatibility with V. radiata cv. KPS2, but it promoted nodulation in other varieties of V. radiata, including KPS1. Interestingly, NopE1 and its paralogue NopE2, which exhibits calcium-dependent autocleavage, yield similar results in modulating KPS1 nodulation. Furthermore, NopE is required for early infection and nodule organogenesis in compatible plants. Evolutionary analysis revealed that NopE is highly conserved among bradyrhizobia and plant-associated endophytic and pathogenic bacteria. Our findings suggest that V. radiata and B. diazoefficiens USDA110 may use NopE to optimize their symbiotic interactions by reducing phytohormone-mediated ETI-type (PmETI) responses via salicylic acid (SA) biosynthesis suppression.

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Tracking the Secretion of Fluorescently Labeled Type III Effectors from Single Bacteria in Real Time

Methods in Molecular Biology - Protein Secretion ◽

10.1007/978-1-60327-412-8_14 ◽

2010 ◽

pp. 241-256 ◽

Cited By ~ 3

Author(s):

Nandi Simpson ◽

Laurent Audry ◽

Jost Enninga

Keyword(s):

Real Time ◽

Type Iii Effectors ◽

Type Iii

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Identification of type III effectors modulating the symbiotic properties of Bradyrhizobium vignae strain ORS3257 with various Vigna species

Scientific Reports ◽

10.1038/s41598-021-84205-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Pongpan Songwattana ◽

Clémence Chaintreuil ◽

Jenjira Wongdee ◽

Albin Teulet ◽

Mamadou Mbaye ◽

...

Keyword(s):

Positive Impact ◽

Symbiotic Efficiency ◽

Type Iii Effectors ◽

Type Iii ◽

Vigna Species ◽

Symbiotic Properties

AbstractThe Bradyrhizobium vignae strain ORS3257 is an elite strain recommended for cowpea inoculation in Senegal. This strain was recently shown to establish symbioses on some Aeschynomene species using a cocktail of Type III effectors (T3Es) secreted by the T3SS machinery. In this study, using a collection of mutants in different T3Es genes, we sought to identify the effectors that modulate the symbiotic properties of ORS3257 in three Vigna species (V. unguiculata, V. radiata and V. mungo). While the T3SS had a positive impact on the symbiotic efficiency of the strain in V. unguiculata and V. mungo, it blocked symbiosis with V. radiata. The combination of effectors promoting nodulation in V. unguiculata and V. mungo differed, in both cases, NopT and NopAB were involved, suggesting they are key determinants for nodulation, and to a lesser extent, NopM1 and NopP1, which are additionally required for optimal symbiosis with V. mungo. In contrast, only one effector, NopP2, was identified as the cause of the incompatibility between ORS3257 and V. radiata. The identification of key effectors which promote symbiotic efficiency or render the interaction incompatible is important for the development of inoculation strategies to improve the growth of Vigna species cultivated in Africa and Asia.

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The Proteasome Acts as a Hub for Plant Immunity and Is Targeted by Pseudomonas Type III Effectors

PLANT PHYSIOLOGY ◽

10.1104/pp.16.00808 ◽

2016 ◽

Vol 172 (3) ◽

pp. 1941-1958 ◽

Cited By ~ 37

Author(s):

Suayib Üstün ◽

Arsheed Sheikh ◽

Selena Gimenez-Ibanez ◽

Alexandra Jones ◽

Vardis Ntoukakis ◽

...

Keyword(s):

Plant Immunity ◽

Type Iii Effectors ◽

Type Iii

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Genome context influences evolutionary flexibility of nearly identical type III effectors in two phytopathogenic Pseudomonads

10.1101/2021.11.22.469601 ◽

2021 ◽

Author(s):

David A Baltrus ◽

Qian Feng ◽

Brian H Kvitko

Keyword(s):

Pseudomonas Syringae ◽

Evolutionary Dynamics ◽

Effector Proteins ◽

In Planta ◽

Genomic Context ◽

Type Iii Effectors ◽

Type Iii ◽

Genome Context ◽

The Impact ◽

Multiple Type

Integrative Conjugative Elements (ICEs) are replicons that can insert and excise from chromosomal locations in a site specific manner, can conjugate across strains, and which often carry a variety of genes useful for bacterial growth and survival under specific conditions. Although ICEs have been identified and vetted within certain clades of the agricultural pathogen Pseudomonas syringae, the impact of ICE carriage and transfer across the entire P. syringae species complex remains underexplored. Here we identify and vet an ICE (PmaICE-DQ) from P. syringae pv. maculicola ES4326, a strain commonly used for laboratory virulence experiments, demonstrate that this element can excise and conjugate across strains, and contains loci encoding multiple type III effector proteins. Moreover, genome context suggests that another ICE (PmaICE-AOAB) is highly similar in comparison with and found immediately adjacent to PmaICE-DQ within the chromosome of strain ES4326, and also contains multiple type III effectors. Lastly, we present passage data from in planta experiments that suggests that genomic plasticity associated with ICEs may enable strains to more rapidly lose type III effectors that trigger R-gene mediated resistance in comparison to strains where nearly isogenic effectors are not present in ICEs. Taken together, our study sheds light on a set of ICE elements from P. syringae pv. maculicola ES4326 and highlights how genomic context may lead to different evolutionary dynamics for shared virulence genes between strains.

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Genome-Assisted Development of a Diagnostic Protocol for Distinguishing High Virulence Pseudomonas syringae pv. tomato Strains

Plant Disease ◽

10.1094/pdis-08-14-0833-re ◽

2015 ◽

Vol 99 (4) ◽

pp. 527-534 ◽

Cited By ~ 5

Author(s):

Lisa A. Jones ◽

Surya Saha ◽

Alan Collmer ◽

Christine D. Smart ◽

Magdalen Lindeberg

Keyword(s):

New York ◽

Pseudomonas Syringae ◽

Genome Comparison ◽

Type Iii Effectors ◽

Type Iii ◽

Host Interaction ◽

Group I ◽

Virulent Strains ◽

High Virulence ◽

Relationship Of

A severe outbreak of bacterial speck of tomato, caused by Pseudomonas syringae pv. tomato, occurred in central New York in 2009. Isolate 09150, collected from this outbreak and subsequently named NYS-T1, was found to be highly virulent on tomato. To better understand the relationship of 09150 to other P. syringae strains and develop a diagnostic assay for aggressive strains of this pathogen, the 09150 genome was sequenced. Genome comparison revealed it to be highly similar to a previously sequenced isolate, T1. Genetic factors linked to host interaction including type III effectors, toxin biosynthetic genes, and elicitors of host innate immunity were identified. Type III effector repertoires were compared with other strains in the high virulence T1-like subgroup and lower virulence DC3000/P. syringae pv. maculicola subgroup within P. syringae phylogenetic Group I. Primers for conventional PCR were developed using sequences for avrA, hopW, conserved in the former subgroup and hopN, present in the latter. These were tested on isolates in the two subgroups, other pseudomonads, and other bacterial pathogens of tomato. Primers developed for avaA and hopW were diagnostic for more virulent strains of P. syringae pv. tomato while primers for hopN were diagnostic for P. syringae pv. tomato DC3000 and related P. syringe pv. maculicola strains. Primers designed against hopR distinguished both of these P. syringae subgroups from other P. syringae strains.

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