Functional diversification of the <i>GALA</i> type III effector family contributes to <i>Ralstonia solanacearum</i> adaptation on different plant hosts

Remigi, Philippe; Anisimova, Maria; Guidot, Alice; Genin, Stéphane; Peeters, Nemo

doi:10.1111/j.1469-8137.2011.03854.x

Cited by 97 publications

(96 citation statements)

References 64 publications

(140 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…AWR5-and, to a lesser extent, AWR2 and AWR1-triggered the major responses in nonhost tobacco plants, whereas Arabidopsis plants showed some recognition of AWR5 and AWR4. Thus, AWR exhibit functional diversification, as was recently described by another R. solanacearum type III effector family showing specialized roles in pathogenicity on different plant hosts (Remigi et al 2011). Our results in A. thaliana are especially interesting.…”

Section: Discussionsupporting

confidence: 57%

The awr Gene Family Encodes a Novel Class of Ralstonia solanacearum Type III Effectors Displaying Virulence and Avirulence Activities

Solé¹,

Popa²,

Mith³

et al. 2012

MPMI

View full text Add to dashboard Cite

We present here the characterization of a new gene family, awr, found in all sequenced Ralstonia solanacearum strains and in other bacterial pathogens. We demonstrate that the five paralogues in strain GMI1000 encode type III-secreted effectors and that deletion of all awr genes severely impairs its capacity to multiply in natural host plants. Complementation studies show that the AWR (alanine-tryptophanarginine tryad) effectors display some functional redundancy, although AWR2 is the major contributor to virulence. In contrast, the strain devoid of all awr genes (Δawr1-5) exhibits enhanced pathogenicity on Arabidopsis plants. A gain-of-function approach expressing AWR in Pseudomonas syringae pv. tomato DC3000 proves that this is likely due to effector recognition, because AWR5 and AWR4 restrict growth of this bacterium in Arabidopsis. Transient overexpression of AWR in nonhost tobacco species caused macroscopic cell death to varying extents, which, in the case of AWR5, shows characteristics of a typical hypersensitive response. Our work demonstrates that AWR, which show no similarity to any protein with known function, can specify either virulence or avirulence in the interaction of R. solanacearum with its plant hosts.

show abstract

Section: Discussionsupporting

confidence: 57%

The awr Gene Family Encodes a Novel Class of Ralstonia solanacearum Type III Effectors Displaying Virulence and Avirulence Activities

Solé¹,

Popa²,

Mith³

et al. 2012

MPMI

View full text Add to dashboard Cite

show abstract

“…xopAC was expressed under the control of the promoter of the GALA7 effector [34]. Xcc and Rs T3S systems are closely related so proteins from one genus can be secreted by the T3S system of the other [35,36].…”

Section: Resultsmentioning

confidence: 99%

xopAC-triggered Immunity against Xanthomonas Depends on Arabidopsis Receptor-Like Cytoplasmic Kinase Genes PBL2 and RIPK

et al. 2013

View full text Add to dashboard Cite

Xanthomonas campestris pv. campestris (Xcc) colonizes the vascular system of Brassicaceae and ultimately causes black rot. In susceptible Arabidopsis plants, XopAC type III effector inhibits by uridylylation positive regulators of the PAMP-triggered immunity such as the receptor-like cytoplasmic kinases (RLCK) BIK1 and PBL1. In the resistant ecotype Col-0, xopAC is a major avirulence gene of Xcc. In this study, we show that both the RLCK interaction domain and the uridylyl transferase domain of XopAC are required for avirulence. Furthermore, xopAC can also confer avirulence to both the vascular pathogen Ralstonia solanacearum and the mesophyll-colonizing pathogen Pseudomonas syringae indicating that xopAC-specified effector-triggered immunity is not specific to the vascular system. In planta, XopAC-YFP fusions are localized at the plasma membrane suggesting that XopAC might interact with membrane-localized proteins. Eight RLCK of subfamily VII predicted to be localized at the plasma membrane and interacting with XopAC in yeast two-hybrid assays have been isolated. Within this subfamily, PBL2 and RIPK RLCK genes but not BIK1 are important for xopAC-specified effector-triggered immunity and Arabidopsis resistance to Xcc.

show abstract

“…(i) Simulation from the profile HMM: Each TR unit in a sequence was sampled from a profile HMM and (ii) Simulation by TR unit duplication: one TR unit is sampled from a profile HMM but the consequent TR units are generated by duplicating a part of the existing TR sequence. AFP = AFP repeat (PF02420); LRR = GALA LRR (31,32); ZNF = zink finger domain (PF00096); SPT = spectrin repeat (PF00435).…”

Section: Methodsmentioning

confidence: 99%

Graph-based modeling of tandem repeats improves global multiple sequence alignment

Szalkowski

Anisimova

2013

Nucleic Acids Research

Self Cite

View full text Add to dashboard Cite

Tandem repeats (TRs) are often present in proteins with crucial functions, responsible for resistance, pathogenicity and associated with infectious or neurodegenerative diseases. This motivates numerous studies of TRs and their evolution, requiring accurate multiple sequence alignment. TRs may be lost or inserted at any position of a TR region by replication slippage or recombination, but current methods assume fixed unit boundaries, and yet are of high complexity. We present a new global graph-based alignment method that does not restrict TR unit indels by unit boundaries. TR indels are modeled separately and penalized using the phylogeny-aware alignment algorithm. This ensures enhanced accuracy of reconstructed alignments, disentangling TRs and measuring indel events and rates in a biologically meaningful way. Our method detects not only duplication events but also all changes in TR regions owing to recombination, strand slippage and other events inserting or deleting TR units. We evaluate our method by simulation incorporating TR evolution, by either sampling TRs from a profile hidden Markov model or by mimicking strand slippage with duplications. The new method is illustrated on a family of type III effectors, a pathogenicity determinant in agriculturally important bacteria Ralstonia solanacearum. We show that TR indel rate variation contributes to the diversification of this protein family.

show abstract

Functional diversification of the GALA type III effector family contributes to Ralstonia solanacearum adaptation on different plant hosts

Cited by 97 publications

References 64 publications

The awr Gene Family Encodes a Novel Class of Ralstonia solanacearum Type III Effectors Displaying Virulence and Avirulence Activities

The awr Gene Family Encodes a Novel Class of Ralstonia solanacearum Type III Effectors Displaying Virulence and Avirulence Activities

xopAC-triggered Immunity against Xanthomonas Depends on Arabidopsis Receptor-Like Cytoplasmic Kinase Genes PBL2 and RIPK

Graph-based modeling of tandem repeats improves global multiple sequence alignment

Contact Info

Product

Resources

About