Effectors and Plant Immunity
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Effectors and Plant Immunity
Strategies of plant defense and microbe attacks
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PLOS ONE: xopAC-triggered Immunity against Xanthomonas Depends on Arabidopsis Receptor-Like Cytoplasmic Kinase Genes PBL2 and RIPK (2013)

PLOS ONE: xopAC-triggered Immunity against Xanthomonas Depends on Arabidopsis Receptor-Like Cytoplasmic Kinase Genes PBL2 and RIPK (2013) | Effectors and Plant Immunity | Scoop.it

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.

 

Endrick Guy, Martine Lautier, Matthieu Chabannes, Brice Roux, Emmanuelle Lauber,  Matthieu Arlat, Laurent D. Noël

 

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PLOS Pathogens: Genomic Analysis of the Kiwifruit Pathogen Pseudomonas syringae pv. actinidiae Provides Insight into the Origins of an Emergent Plant Disease (2013)

PLOS Pathogens: Genomic Analysis of the Kiwifruit Pathogen Pseudomonas syringae pv. actinidiae Provides Insight into the Origins of an Emergent Plant Disease (2013) | Effectors and Plant Immunity | Scoop.it

The origins of crop diseases are linked to domestication of plants. Most crops were domesticated centuries – even millennia – ago, thus limiting opportunity to understand the concomitant emergence of disease. Kiwifruit (Actinidia spp.) is an exception: domestication began in the 1930s with outbreaks of canker disease caused by P. syringae pv. actinidiae(Psa) first recorded in the 1980s. Based on SNP analyses of two circularized and 34 draft genomes, we show that Psa is comprised of distinct clades exhibiting negligible within-clade diversity, consistent with disease arising by independent samplings from a source population. Three clades correspond to their geographical source of isolation; a fourth, encompassing thePsa-V lineage responsible for the 2008 outbreak, is now globally distributed. Psa has an overall clonal population structure, however, genomes carry a marked signature of within-pathovar recombination. SNP analysis of Psa-V reveals hundreds of polymorphisms; however, most reside within PPHGI-1-like conjugative elements whose evolution is unlinked to the core genome. Removal of SNPs due to recombination yields an uninformative (star-like) phylogeny consistent with diversification of Psa-V from a single clone within the last ten years. Growth assays provide evidence of cultivar specificity, with rapid systemic movement of Psa-V inActinidia chinensis. Genomic comparisons show a dynamic genome with evidence of positive selection on type III effectors and other candidate virulence genes. Each clade has highly varied complements of accessory genes encoding effectors and toxins with evidence of gain and loss via multiple genetic routes. Genes with orthologs in vascular pathogens were found exclusively within Psa-V. Our analyses capture a pathogen in the early stages of emergence from a predicted source population associated with wild Actinidia species. In addition to candidate genes as targets for resistance breeding programs, our findings highlight the importance of the source population as a reservoir of new disease.


Via Kamoun Lab @ TSL
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INRA - Diabrotica virgifera: La chrysomèle des racines du maïs entre en résistance

INRA - Diabrotica virgifera: La chrysomèle des racines du maïs entre en résistance | Effectors and Plant Immunity | Scoop.it

La larve de la Chrysomèle des racines du maïs fait des ravages dans ces cultures. Dans les champs d’Amérique du Nord, ses dégâts s’élèveraient à plus d’un milliard de dollars. D’où l’inquiétude des agriculteurs français et la mobilisation de l’Inra peu après l’apparition des premiers foyers français en 2002.

Petit coléoptère probablement originaire d'Amérique centrale, la Chrysomèle des racines du maïs, Diabrotica virgifera virgifera LeConte, est devenue, au cours des années 60, le principal ravageur du maïs en Amérique du Nord. Signalée en Europe centrale en 1992, en France en 2002, les foyers se développent sur ce continent. L'Inra mène des recherches pour comprendre ces invasions, gérer les populations et lutter contre ce ravageur.

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Five phylogenetically close rice SWEET genes confer TAL effector-mediated susceptibility to Xanthomonas oryzae pv. oryzae - New Phytologist

Five phylogenetically close rice SWEET genes confer TAL effector-mediated susceptibility to Xanthomonas oryzae pv. oryzae - New Phytologist | Effectors and Plant Immunity | Scoop.it

Streubel et al, 2013

Only a few plant target genes of TAL effectors have been identified, so far. Three plant SWEET genes encoding
putative sugar transporters are known to be induced by TAL effectors from rice-pathogenic Xanthomonas oryzae pv. oryzae (Xoo).
  We predict and validate that expression of OsSWEET14 is induced by a novel TAL effector, Tal5, from an African Xoo strain. Artificial TAL effectors (ArtTALs) were constructed to individually target 20 SWEET orthologs in rice. They were used as designer virulence factors to study which rice SWEET genes can support Xoo virulence.
  The Tal5 target box differs from those of the already known TAL effectors TalC, AvrXa7 and PthXo3, which also induce expression of OsSWEET14, suggesting evolutionary convergence on key targets. ArtTALs efficiently complemented an Xoo talC mutant, demonstrating that specific induction of OsSWEET14 is the key target of TalC. ArtTALs that specifically target
individual members of the rice SWEET family revealed three known and two novel SWEET genes to support bacterial virulence.
  Our results demonstrate that five phylogenetically close SWEET proteins, which presumably act as sucrose transporters, can support Xoo virulence.


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Genome Announc.: Genome Sequences of Three Atypical Xanthomonas campestris pv. campestris Strains, CN14, CN15, and CN16 (2013)

Xanthomonas campestris pv. campestris is the causal agent of black rot on Brassicaceae. The draft genome sequences of three strains (CN14, CN15, and CN16) that are highly aggressive on Arabidopsis have been determined. These genome sequences present an unexpected genomic diversity in X. campestris pv. campestris, which will be valuable for comparative analyses.

 

Bolot S, Roux B, Carrere S, Jiang B-L, Tang J-L, Arlat M, Noël LD.

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Front. Plant Sci.: Research Topic on Nuclear components and dynamics during plant innate immunity (2013)

Front. Plant Sci.: Research Topic on Nuclear components and dynamics during plant innate immunity (2013) | Effectors and Plant Immunity | Scoop.it

In plants, efficient immune responses against microbial infection depend on the ability to rapidly couple pathogen recognition to downstream signaling responses. In this context, plant immunity requires highly dynamic responses that involve multiple organelles during the recognition and signaling events associated to defense. Nuclear dynamics plays a critical role in plant immunity based to the growing number of reports revealing that nuclear localization of pathogen effectors, plant disease resistance proteins, and key plant components, including transcription factors and regulators, are essential for immunity.

Following their delivery into plant cells, a significant number of effector proteins from different pathogenic microorganisms, including viruses, oomycetes, fungi, nematodes, and bacteria, are targeted to the nucleus by co-opting the host nuclear import machinery. This suggests that effectors may manipulate host transcription or directly target essential host nuclear components for the benefit of the pathogen. Indeed, pathogen-induced transcriptional regulation in host cells plays a crucial role in the establishment of plant defense and associated plant cell death responses. Along these lines, it has been estimated that about 25% of Arabidopsis genes are transcriptionally regulated in response to pathogen infection and a significant number of transcription factors are involved in the defense gene regulation. Moreover, spatial restriction of defense regulators by the nuclear envelope as well as their stimulus-induced nuclear translocation provide an important mechanism for defense regulation, as their level of nuclear accumulation determines the magnitude of the defense response. In addition, nuclear translocation of effectors may also affect subcellular localization of their cognate resistance proteins in a process that is essential for plant immunity. Finally, mutations in plant cellular factors involved in the transport of macromolecules through the nuclear envelope compromise plant resistance signaling, underlining the importance of nucleocytoplasmic trafficking during plant innate immunity. Together, these findings situate the nucleus at the forefront of the mutual recognition between plants and pathogens.

In this Research Topic, we aim to provide an open-access update on the current knowledge about the importance of nuclear components – both from the “microbial side” and from the “plant side”- and nuclear dynamics during the establishment of plant immune responses. We will collect Original Research and Review papers on the topic, but also other article types, such as Methods, Commentaries and Opinions are welcome.

 

Topic Editors: Susana Rivas and Laurent Deslandes

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PNAS: Perception of conserved pathogen elicitors at the plasma membrane leads to relocalization of the Arabidopsis PEN3 transporter (2013)

PNAS: Perception of conserved pathogen elicitors at the plasma membrane leads to relocalization of the Arabidopsis PEN3 transporter (2013) | Effectors and Plant Immunity | Scoop.it

The Arabidopsis PENETRATION RESISTANCE 3 (PEN3) ATP binding cassette transporter participates in nonhost resistance to fungal and oomycete pathogens and is required for full penetration resistance to the barley powdery mildew Blumeria graminis f. sp. hordei. PEN3 resides in the plasma membrane and is recruited to sites of attempted penetration by invading fungal appressoria, where the transporter shows strong focal accumulation. We report that recruitment of PEN3 to sites of pathogen detection is triggered by perception of pathogen-associated molecular patterns, such as flagellin and chitin. PEN3 recruitment requires the corresponding pattern recognition receptors but does not require the BAK1 coreceptor. Pathogen- and pathogen-associated molecular pattern-induced focal accumulation of PEN3 and the PENETRATION RESISTANCE 1 (PEN1) syntaxin show differential sensitivity to specific pharmacological inhibitors, indicating distinct mechanisms for recruitment of these defense-associated proteins to the host–pathogen interface. Focal accumulation of PEN3 requires actin but is not affected by inhibitors of microtubule polymerization, secretory trafficking, or protein synthesis, and plasmolysis experiments indicate that accumulation of PEN3 occurs outside of the plasma membrane within papillae. Our results implicate pattern recognition receptors in the recruitment of defense-related proteins to sites of pathogen detection. Additionally, the process through which PEN3 is recruited to the host–pathogen interface is independent of new protein synthesis and BFA-sensitive secretory trafficking events, suggesting that existing PEN3 is redirected through an unknown trafficking pathway to sites of pathogen detection for export into papillae.

 

William Underwood and Shauna C. Somerville

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Plant Phys: Regulation of transcription of NB-LRR-encoding genes SNC1 and RPP4 via H3K4 tri-methylation (2013)

Plant Phys: Regulation of transcription of NB-LRR-encoding genes SNC1 and RPP4 via H3K4 tri-methylation (2013) | Effectors and Plant Immunity | Scoop.it

Plant nucleotide-binding leucine-rich repeat (NB-LRR) proteins serve as intracellular sensors to detect pathogen effectors and trigger immune responses. Transcription of the NB-LRR-encoding Resistance (R) genes needs to be tightly controlled to avoid inappropriate defense activation. How the expression of the NB-LRR R genes is regulated is poorly understood. The Arabidopsis snc1 mutant carries a gain-of-function mutation in a TIR-NB-LRR-encoding gene, resulting in the constitutive activation of plant defence responses. A snc1 suppressor screen identified modifier of snc1, 9 (mos9), which partially suppresses the autoimmune phenotypes of snc1. Positional cloning revealed that MOS9 encodes a plant-specific protein of unknown function. Expression analysis showed that MOS9 is required for the full expression of TIR-NB-LRR protein-encoding RPP4 and SNC1, both of which reside in the RPP4 cluster. Co-immunoprecipitation and mass spectrometry analyses revealed that MOS9 associates with the Set1 class H3K4 methyl transferase ATXR7. Like MOS9, ATXR7 is also required for the full expression of SNC1 and the autoimmune phenotypes in the snc1 mutant. In atxr7 mutant plants, the expression of RPP4 is similarly reduced and resistance against Hyaloperonospora arabidopsidis Emwa1 is compromised. Consistent with the attenuated expression of SNC1 and RPP4, H3K4me3 marks are reduced around the promoters of SNC1 and RPP4 in mos9 plants. Our data suggest that MOS9 functions together with ATXR7 to regulate the expression of SNC1 and RPP4 through H3K4 methylation, which plays an important role in fine-tuning their transcription levels and functions in plant defence.


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Plant Cell: The Receptor-Like Protein ReMAX of Arabidopsis Detects the Microbe-Associated Molecular Pattern eMax from Xanthomonas (2013)

Plant Cell: The Receptor-Like Protein ReMAX of Arabidopsis Detects the Microbe-Associated Molecular Pattern eMax from Xanthomonas (2013) | Effectors and Plant Immunity | Scoop.it

As part of their immune system, plants have pattern recognition receptors (PRRs) that can detect a broad range of microbe-associated molecular patterns (MAMPs). Here, we identified a PRR of Arabidopsis thaliana with specificity for the bacterialMAMP eMax from xanthomonads. Response to eMax seems to be restricted to theBrassicaceae family and also varied among different accessions of Arabidopsis. In crosses between sensitive accessions and the insensitive accession Shakhdara, eMax perception mapped to RECEPTOR-LIKE PROTEIN1 (RLP1). Functional complementation of rlp1 mutants required gene constructs that code for a longer version of RLP1 that we termed ReMAX (for receptor of eMax). ReMAX/RLP1 is a typical RLP with structural similarity to the tomato (Solanum lycopersicum) RLP Eix2, which detects fungal xylanase as a MAMP. Attempts to demonstrate receptor function by interfamily transfer of ReMAX to Nicotiana benthamiana were successful after using hybrid receptors with the C-terminal part of ReMAX replaced by that of Eix2. These results show that ReMAX determines specificity for eMax. They also demonstrate hybrid receptor technology as a promising tool to overcome problems that impede interfamily transfer of PRRs to enhance pathogen detection in crop plants.


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Genome Biology: Interactions of beneficial and detrimental root-colonizing filamentous microbes with plant hosts (2013)

Genome Biology: Interactions of beneficial and detrimental root-colonizing filamentous microbes with plant hosts (2013) | Effectors and Plant Immunity | Scoop.it

Understanding commonalities and differences of how symbiotic and parasitic microbes interact with plants will improve advantageous interactions and allow pathogen control strategies in crops. Recently established systems enable studies of root pathogenic and symbiotic interactions in the same plant species.


Via Kamoun Lab @ TSL
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João Miguel Correia Teixeira's comment, July 4, 2013 6:14 AM
Very nice initiative! You continue to surprise me the same way you did the first day we met ;-)
Ronaldo Dalio's curator insight, February 18, 2014 6:56 AM

Muito interessante. Carol, Ina e Paulo, acho este paper importante pro projeto de vcs!

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Pseudomonas syringae pv. tomato DC3000: A Model Pathogen for Probing Disease Susceptibility and Hormone Signaling in Plants

Pseudomonas syringae pv. tomato DC3000: A Model Pathogen for Probing Disease Susceptibility and Hormone Signaling in Plants | Effectors and Plant Immunity | Scoop.it

Scooped from: Annual Review of Phytopathology, 2013
Authors: Xiu-Fang Xin and Sheng Yang He

Summary: Since the early 1980s, various strains of the gram-negative bacterial pathogen Pseudomonas syringae have been used as models for understanding plant-bacterial interactions. In 1991, a P. syringae pathovar tomato (Pst) strain, DC3000, was reported to infect not only its natural host tomato but also Arabidopsis in the laboratory, a finding that spurred intensive efforts in the subsequent two decades to characterize the molecular mechanisms by which this strain causes disease in plants. Genomic analysis shows that Pst DC3000 carries a large repertoire of potential virulence factors, including proteinaceous effectors that are secreted through the type III secretion system and a polyketide phytotoxin called coronatine, which structurally mimics the plant hormone jasmonate ( JA). Study of Pst DC3000 pathogenesis has not only provided several conceptual advances in understanding how a bacterial pathogen employs type III effectors to suppress plant immune responses and promote disease susceptibility but has also facilitated the discovery of the immune function of stomata and key components of JA signaling in plants. The concepts derived from the study of Pst DC3000 pathogenesis may prove useful in understanding pathogenesis mechanisms of other plant pathogens.


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Damien Meyer's curator insight, June 19, 2013 3:25 PM

remarkable review

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Mol. Mic.: RNA-Seq facilitates a new perspective on signal transduction and gene regulation in important plant pathogens (2013)

Mol. Mic.: RNA-Seq facilitates a new perspective on signal transduction and gene regulation in important plant pathogens (2013) | Effectors and Plant Immunity | Scoop.it

RNA-Seq is opening new doors for the functional understanding of microorganisms. Advances in RNA-Seq technology are allowing investigators to focus their studies on specific functional questions. An interesting example is presented by An et al. (2013) in this issue of Molecular Microbiology. New genes were identified for proteins and ncRNAs when the authors concentrated on the role of the rpf genes, which code for key components of a signal transduction hub in the plant pathogen Xanthomonas campestris pv. campestris. Although rpf gene products were already known to be involved in controlling transcription of many genes, including those encoding several important virulence factors, novel and unexpected properties of this signal transduction system emerged from the RNA-Seq analysis. In addition to identifying new target genes influenced by the rpf genes, the study found that the regulons of RpfC and RpfG, the sensor and response regulator of the master two-component regulatory system, only partially overlapped, indicating that the Rpf signalling system is even more complex than previously appreciated.

 

Frank-Jörg Vorhölter

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mBio: Natural Genetic Variation of Xanthomonas campestris pv. campestris Pathogenicity on Arabidopsis Revealed by Association and Reverse Genetics (2013)

mBio: Natural Genetic Variation of Xanthomonas campestris pv. campestris Pathogenicity on Arabidopsis Revealed by Association and Reverse Genetics (2013) | Effectors and Plant Immunity | Scoop.it

The pathogenic bacterium Xanthomonas campestris pv. campestris, the causal agent of black rot of Brassicaceae, manipulates the physiology and the innate immunity of its hosts. Association genetic and reverse-genetic analyses of a world panel of 45 X. campestris pv. campestris strains were used to gain understanding of the genetic basis of the bacterium’s pathogenicity to Arabidopsis thaliana. We found that the compositions of the minimal predicted type III secretome varied extensively, with 18 to 28 proteins per strain. There were clear differences in aggressiveness of those X. campestris pv. campestris strains on two Arabidopsis natural accessions. We identified 3 effector genes (xopAC, xopJ5, and xopAL2) and 67 amplified fragment length polymorphism (AFLP) markers that were associated with variations in disease symptoms. The nature and distribution of the AFLP markers remain to be determined, but we observed a low linkage disequilibrium level between predicted effectors and other significant markers, suggesting that additional genetic factors make a meaningful contribution to pathogenicity. Mutagenesis of type III effectors in X. campestris pv. campestris confirmed that xopAC functions as both a virulence and an avirulence gene in Arabidopsis and that xopAM functions as a second avirulence gene on plants of the Col-0 ecotype. However, we did not detect the effect of any other effector in the X. campestris pv. campestris 8004 strain, likely due to other genetic background effects. These results highlight the complex genetic basis of pathogenicity at the pathovar level and encourage us to challenge the agronomical relevance of some virulence determinants identified solely in model strains.

 

IMPORTANCE The identification and understanding of the genetic determinants of bacterial virulence are essential to be able to design efficient protection strategies for infected plants. The recent availability of genomic resources for a limited number of pathogen isolates and host genotypes has strongly biased our research toward genotype-specific approaches. Indeed, these do not consider the natural variation in both pathogens and hosts, so their applied relevance should be challenged. In our study, we exploited the genetic diversity of Xanthomonas campestris pv. campestris, the causal agent of black rot on Brassicaceae (e.g., cabbage), to mine for pathogenicity determinants. This work evidenced the contribution of known and unknown loci to pathogenicity relevant at the pathovar level and identified these virulence determinants as prime targets for breeding resistance to X. campestris pv. campestris in Brassicaceae.

 

Endrick Guy, Anne Genissel, Ahmed Hajric, Matthieu Chabannes, Perrine David, Sébastien Carrere, Martine Lautier, Brice Roux, Tristan Boureau, Matthieu Arlat, Stéphane Poussierf, Laurent D. Noël

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Trends Plant Sci.: Hormone defense networking in rice: tales from a different world (2013)

Trends Plant Sci.: Hormone defense networking in rice: tales from a different world (2013) | Effectors and Plant Immunity | Scoop.it

Recent advances in plant immunity research underpin the pivotal role of small-molecule hormones in regulating the plant defense signaling network. Although most of our understanding comes from studies of dicot plants such as Arabidopsis thaliana, new studies in monocots are providing additional insights into the defense-regulatory role of phytohormones. Here, we review the roles of both classical and more recently identified stress hormones in regulating immunity in the model monocot rice (Oryza sativa) and highlight the importance of hormone crosstalk in shaping the outcome of rice–pathogen interactions. We also propose a defense model for rice that does not support a dichotomy between the pathogen lifestyle and the effectiveness of the archetypal defense hormones salicylic acid (SA) and jasmonic acid (JA).

 

David De Vleesschauwer, Godelieve Gheysen, Monica Höfte

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XVI IS-MPMI 2014, Rhodes, Greece: Confirmed invited chairs and speakers

XVI IS-MPMI 2014, Rhodes, Greece: Confirmed invited chairs and speakers | Effectors and Plant Immunity | Scoop.it

Opening lecture:

Fred Ausubel (Massachusetts, USA) - Signaling in Host-Pathogen Interactions

 

Plenary sessions:

Nondas Paplomatas (Agricultural University of  Athens, Greece)

Bart Thomma (University of Wageningen, The Netherlands) - Biological functions of fungal effectors in suppression of plant immunity

Jean-François Laliberté (INRS - Québec, Canada) - Symplasmic and vascular movement of turnip mosaic virus

Wenbo Ma (UC Riverside, USA) - Phytophthora effectors promote infection by suppressing RNA silencing

Melissa Goellner Mitchum (University of  Missouri - Columbia, USA) - Signaling in Plant-Nematode Interactions

Ioannis (Yiannis) Stergiopoulos (UC Davis, USA) - Biochemical and structural analysis of fungal core effector proteins

Natalia Requena (KIT Karlsruhe, Germany) - Fungal words in the arbuscular mycorrhizal (AM) symbiotic dialogue

Antonis Rokas (Vanderbilt University - Nashville, U.S.A.) - The Evolution of Fungal Chemodiversity

Andrew Bent (University of Wisconsin - Madison, USA) - Cyst nematode resistance: a major plant disease resistance trait operates via novel mechanisms

Detlef Weigel (Max Planck Institute - Tübingen, Germany) - Insights into the plant immune system from the study of autoimmunity in hybrids

Tina Romeis (Free University of Berlin, Germany) - CDPK signaling in plant immune responses

Cyril  Zipfel (Sainsbury Laboratory, UK) - Early surface immune signalling

Jeff  Dangl (UNC Chapel Hill, USA) - The plant immune system and root microbiome

Julia Vorholt (ETH Zürich, Switzerland) - The phyllosphere microbiome: responses to and impacts on plants

Dingzhong Tang (Institute of Genetics and Developmental Biology -Beijing, China) - The role of Exocyst in plant immunity

Gary Stacey (University of  Missouri, Columbia, USA) - Elucidation of novel signaling pathways that mediate plant-pathogen and plant-symbiont interactions

Georg Felix (University of Tübingen, Germany) - Ligand-specifity of plant pattern recognition receptors

Roger Innes (University of Indiana - Bloomington, USA) - Regulation of endomembrane trafficking following activation of plant defense responses

Francis Martin (INRA Nancy - Champenoux, France) - Exploring the diversity of mycorrhizal symbiosis molecular toolboxes throughout the fungal tree of life

Brian J Staskawicz (UC Berkeley, USA) - Role of Pathogen Effectors in Plant Innate Immunity: Recognition and Induced Susceptibility

Seogchan Kang (University Park PA, USA) - Microbial volatile organic compounds: Ancient signals that mediate inter- and intra-kingdom communications

Erh-Min Lai (IPMB-Taipei, Taiwan) - Type VI secretion system in Agrobacterium tumefaciens: mechanisms and biology

Libo   Shan (Texas A&M, USA)  -Modulation of PTI signaling by phosphorylation and ubiquitination

Jonathan D.G. Jones (Sainsbury Laboratory, U.K.) - How the RPS4/RRS1 TIR-NB-LRR/ TIR-NB-LRR-WRKY protein complex recognizes effectors AvrRps4 and PopP2, and then activates defence

Hailing Jin (UC Riverside, USA) - Fungal small RNAs act as effectors to suppress plant immunity by hijacking host RNAi machinery

Silke Robatzek (Sainsbury Laboratory, UK ) - Looking inside cells: connecting membrane trafficking and immunity

Nick Panopoulos (IMBB - Crete, Greece) - Phytobacterial effectors - yet more effects

Mary Beth Mudgett - (University of Stanford, CA USA)

 

Concurrent sessions:

James R. Alfano (University of Nebraska - Lincoln, USA) - Pseudomonas syringae type III effectors, their targets, and suppression of plant immunity

Jian-Min Zhou (Center for genome Biology - Beijing, China) - Stomatal movement as a battleground for Arabidopsis-Pseudomonas syringae interaction

Patrick Schäfer (University of Warwick - Wellesbourne, UK) - Root colonisation patterns of the mutualist Piriformospora indica

Jean Greenberg (University of Chicago, USA) - Cant we just work together? Lessons from effectoromics

Sophien Kamoun (The Sainsbury laboratory, UK) - Effector biology in plant-oomycete pathosystems

Michael Udvardi (Samuel Roberts Noble Foundation - Oklahoma, USA) - Fast forward- and reverse genetics of Medicago genes involved in symbiotic nitrogen fixation

David Baulcombe (University of Cambridge, UK) - Transgenerational epigenetic effects in plants- new mechanisms

Jurriaan Ton (University of Sheffield, UK) - Primed Plants Do Not Forget

Jurgen Zeier (Heinrich Heine University - Düsseldorf, Germany) - Amino  acid metabolism in inducible plant resistance: pipecolic acid mediates systemic acquired resistance and defense priming

Dan Klessig (Boyce Thompson Institute - Ithaca, USA) - The CRT1 subfamily of the MORC superfamily participates in multiple levels of immunity against a broad spectrum of pathogens in both dicots and monocots

Rick Mumford (FERA - York, UK) - Next generation plant diagnostics: advances in laboratory and field testing for pests and pathogens

María M. López (IVIA - Valencia, Spain) - Challenges of the diagnostics of plant pathogenic bacteria in the omics era

Renier A. L. van der Hoorn (Max Planck Institute for Plant Breeding - Köln, Germany)

Saskia A. Hogenhout (John Innes Centre, UK)

Barbara Howlett (The University of Melbourne, Australia) - Noticed and neglected fungal diseases of Brassica napus (canola)

Jeffrey G. Ellis (CSIRO Australia) - Flax and wheat stem rust effectors studies

Doil Choi (Seoul National University, Korea)

Paul Schulze-Lefert (Max Planck Institute for Plant Breeding Research, Köln, Germany) - From structure to functions of the Arabidopsis root microbiota

Corne Pieterse (Utrecht University, The Netherlands) - Hormonal modulation of plant immunity

Xinian Dong (Duke University - Durham, USA) - Dynamic regulation of plant immune response

Morten Petersen (University of Copenhagen,  Denmark)

Guo-Liang Wang (The Ohio State University - Columbus, USA) - Molecular dissection of rice immunity to Magnaporthe oryzae

Bostjan Kobe (The University of Queensland - Brisbane, Australia) - Structural basis of TIR domain function in R protein signalling

Pierre de Wit (Wageningen University, The Netherlands) - Various roles for secondary metabolism genes and their products in biotophic and necrotrophic fungal plant pathogens ?

Nicole Clay (Yale University - New Haven, USA) - Conservation and Diversity of MAMP-induced Indole and Phenylpropanoid Genes and Metabolites

Giulia De Lorenzo (Sapienza Università di Roma - Roma, Italy) - Signalling by cell wall-derived damage-associated molecular patterns (DAMPs)

Makoto Hayashi (National Institute of Agrobiological Sciences, Ibaraki, Japan) - Transcriptional activator NIN controls nodule organogenesis

Matteo Lorito (Universita di Napoli “Federico II” - Portici Napoli, Italy) - Disease biocontrol agents are moving from niche to full scale applications: are we technologically ready ?

Ton Bisseling (Wageningen University, The Netherlands) - Intracellular infection, from symbiont to pathogens

Simona Radutoiu (Aarhus University, Denmark) - Perception and accommodation of microbes. Insights from the model legume Lotus japonicus

Darrell Desveaux (University of Toronto - Ontario, Canada) - Type III Effectors and the Plant Immune Response

Gunther Doehlemann (Max Planck Institute for Terrestrial Microbiology - Marburg, Germany) - Suppression of host immunity by Ustilago maydis

Karin Posthuma (Utrecht University, The Netherlands) - Molecular plant pathogen knowledge as a plant breeding too

Giles Oldroyd (John Innes Centre - Norwich, UK) - Discriminating between mycorrhizal fungi and rhizobial bacteria during symbiosis signalling

Rene Geurts (Wageningen University, The Netherlands) - Parasponia provides a genetic blueprint for rhizobium symbiosis

Frank L. W.  Takken (University of Amsterdam, The Netherlands) - The tomato-fusarium pathosystem: a game of hide and seek

Dennis Halterman (USDA/ARS Madison - Wisconsin, USA) - Molecular determinants of late blight resistance mediated by the gene RB

Sheng Yang He (Michigan State University - East Lansing, USA) - Bacterial pathogenesis: insights from a model system and practical implications

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Effectome 2013 - Meeting of the Effectome Network - September 25-27, 2013 - Wimiz

Effectome 2013 - Meeting of the Effectome Network - September 25-27, 2013 - Wimiz | Effectors and Plant Immunity | Scoop.it

Via Elsa Ballini
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Elsa Ballini's curator insight, July 24, 2013 2:21 AM

Program soon available...

 

Speakers:

 

Allyson Maclean , Jonathan Jacobs ,  Adriana Bernal ,  Magdalena Krzymowska , Simon Saucet , Lionel Gagnevin , Orlando Delange , Nicolas Denancé , Jana Streubel ,  Alvaro Perez ,  Sole Montserrat , Lieve Gheysen , Michael Quentin / Bruno Favery , Tina Kindt  , Nathalie Boissot  , Akiko Sugio , Maelle Jaouannet , Sebastian Schornack , Laurence Godiard , Elodie Gaulin , Stam Remco , Caillaud Marie-Cécile , Guido van den Ackerveken ,  Kurt Lamour  , Thomas Rey , Ralph Panstruga , Frey Nicolas , Rouxel Thierry ,  Loehrer Marco , Brunner Frederic ,  Pellegrin Clément , Poppe Stephan , Chanclud Emilie, Duplessis Sébastien

Rose Matchett's curator insight, July 24, 2013 9:02 PM

It's about time.

Damien Meyer's comment, July 25, 2013 4:56 PM
interested by Effectors of the T4SS? and by works on animal and human pathogenic bacteria? Meyer DF@, Noroy C, Moumène C, Raffaele S, Albina E, Vachiéry N. (2013). Searching Algorithm for Type IV secretion system Effectors (S4TE) 1.0 : a tool for predicting type IV effectors and exploring their genomic context. Accepted for publication in Nucleic Acids Research (http://sate.cirad.fr)
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Trends Plant Sci.: Nod factor perception protein carries weight in biotic interactions (2013)

Trends Plant Sci.: Nod factor perception protein carries weight in biotic interactions (2013) | Effectors and Plant Immunity | Scoop.it

Plant plasma membrane-bound receptors with extracellular lysin motif (LysM) domains participate in interactions with microorganisms. In Medicago truncatula, the LysM receptor-like kinase gene nodulation (Nod) factor perception (NFP) is a key gene that controls the perception of rhizobial lipochitooligosaccharide (LCO) Nod factors for the establishment of the Rhizobium–legume symbiosis. In this article, we review recent data that have refined our understanding of this function and that have revealed a role for NFP in the perception of arbuscular mycorrhizal (AM) symbiotic signals and plant pathogenic microorganisms. The dual role of NFP in symbiosis and immunity suggests that this receptor protein controls the perception of different signals and the activation of different downstream signalling pathways. These advances provide new insights into the evolution and functioning of this versatile plant protein.

 

Clare Gough and Christophe Jacquet

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Jean-Michel Ané's comment, July 16, 2013 10:11 AM
I love this topic!
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J. Exp. Bot.: Pathogen-associated molecular pattern-triggered immunity and resistance to the root pathogen Phytophthora parasitica in Arabidopsis (2013)

J. Exp. Bot.: Pathogen-associated molecular pattern-triggered immunity and resistance to the root pathogen Phytophthora parasitica in Arabidopsis (2013) | Effectors and Plant Immunity | Scoop.it

The cellulose binding elicitor lectin (CBEL) of the genus Phytophthora induces necrosis and immune responses in several plant species, including Arabidopsis thaliana. However, the role of CBEL-induced responses in the outcome of the interaction is still unclear. This study shows that some of CBEL-induced defence responses, but not necrosis, required the receptor-like kinase BAK1, a general regulator of basal immunity in Arabidopsis, and the production of a reactive oxygen burst mediated by respiratory burst oxidases homologues (RBOH). Screening of a core collection of 48 Arabidopsis ecotypes using CBEL uncovered a large variability in CBEL-induced necrotic responses. Analysis of non-responsive CBEL lines Ws-4, Oy-0, and Bla-1 revealed that Ws-4 and Oy-0 were also impaired in the production of the oxidative burst and expression of defence genes, whereas Bla-1 was partially affected in these responses. Infection tests using two Phytophthora parasitica strains, Pp310 and Ppn0, virulent and avirulent, respectively, on the Col-0 line showed that BAK1 and RBOH mutants were susceptible to Ppn0, suggesting that some immune responses controlled by these genes, but not CBEL-induced cell death, are required for Phytophthora parasitica resistance. However, Ws-4, Oy-0, and Bla-1 lines were not affected in Ppn0 resistance, showing that natural variability in CBEL responsiveness is not correlated to Phytophthora susceptibility. Overall, the results uncover a BAK1- and RBOH-dependent CBEL-triggered immunity essential for Phytophthora resistance and suggest that natural quantitative variation of basal immunity triggered by conserved general elicitors such as CBEL does not correlate to Phytophthora susceptibility.

 

Mathieu Larroque, Elodie Belmas, Thomas Martinez, Sophie Vergnes, Nathalie Ladouce, Claude Lafitte, Elodie Gaulin, and Bernard Dumas

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MPMI: Induction and Suppression of PEN3 Focal Accumulation During Pseudomonas syringae pv. tomato DC3000 Infection of Arabidopsis (2013)

MPMI: Induction and Suppression of PEN3 Focal Accumulation During Pseudomonas syringae pv. tomato DC3000 Infection of Arabidopsis (2013) | Effectors and Plant Immunity | Scoop.it

The pleiotropic drug resistance (PDR) proteins belong to the super-family of ATP-binding cassette (ABC) transporters. AtPDR8, also called PEN3, is required for penetration resistance of Arabidopsis to nonadapted powdery mildew fungi. During fungal infection, plasma-membrane-localized PEN3 is concentrated at fungal entry sites, as part of the plant's focal immune response. Here, we show that the pen3mutant is compromised in resistance to the bacterial pathogenPseudomonas syringae pv. tomato DC3000. P. syringae pv. tomatoDC3000 infection or treatment with a flagellin-derived peptide, flg22, induced strong focal accumulation of PEN3-green fluorescent protein. Interestingly, after an initial induction of PEN3 accumulation, P. syringae pv. tomato DC3000 but not the type-III-secretion-deficient mutant hrcC could suppress PEN3 accumulation. Moreover, transgenic overexpression of the P. syringae pv. tomato DC3000 effector AvrPto was sufficient to suppress PEN3 focal accumulation in response to flg22. Analyses of P. syringae pv. tomato DC3000 effector deletion mutants showed that individual effectors, including AvrPto, appear to be insufficient to suppress PEN3 accumulation when delivered by bacteria, suggesting a requirement for a combined action of multiple effectors. Collectively, our results indicate that PEN3 plays a positive role in plant resistance to a bacterial pathogen and show that focal accumulation of PEN3 protein may be a useful cellular response marker for theArabidopsis–P. syringae interaction.


Via Kamoun Lab @ TSL
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Plant Physiol.: The Role of TIR-NBS and TIR-X Proteins in Plant Basal Defense Responses (2013)

Plant Physiol.: The Role of TIR-NBS and TIR-X Proteins in Plant Basal Defense Responses (2013) | Effectors and Plant Immunity | Scoop.it

Toll/interleukin receptor (TIR) domain-containing proteins encoded in the Arabidopsis (Arabidopsis thaliana) genome include the TIR-nucleotide binding site (TN) and TIR-unknown site/domain (TX) families. We investigated the function of these proteins. Transient overexpression of five TX and TN genes in tobacco (Nicotiana benthamiana) induced chlorosis. This induced chlorosis was dependent on ENHANCED DISEASE RESISTANCE1, a dependency conserved in both tobacco and Arabidopsis. Stable overexpression transgenic lines of TX and TN genes in Arabidopsis produced a variety of phenotypes associated with basal innate immune responses; these were correlated with elevated levels of salicylic acid. The TN protein AtTN10 interacted with the chloroplastic protein phosphoglycerate dehydrogenase in a yeast (Saccharomyces cerevisiae) two-hybrid screen; other TX and TN proteins interacted with nucleotide binding-leucine-rich repeat proteins and effector proteins, suggesting that TN proteins might act in guard complexes monitoring pathogen effectors.

 

Raja Sekhar Nandety, Jeffery L. Caplan, Keri Cavanaugh, Bertrand Perroud, Tadeusz Wroblewski, Richard W. Michelmore, and Blake C. Meyers

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PLOS ONE: Strategies for Wheat Stripe Rust Pathogenicity Identified by Transcriptome Sequencing (2013)

PLOS ONE: Strategies for Wheat Stripe Rust Pathogenicity Identified by Transcriptome Sequencing (2013) | Effectors and Plant Immunity | Scoop.it

Stripe rust caused by the fungus Puccinia striiformis f.sp. tritici (Pst) is a major constraint to wheat production worldwide. The molecular events that underlie Pst pathogenicity are largely unknown. Like all rusts, Pst creates a specialized cellular structure within host cells called the haustorium to obtain nutrients from wheat, and to secrete pathogenicity factors called effector proteins. We purified Pst haustoria and used next-generation sequencing platforms to assemble the haustorial transcriptome as well as the transcriptome of germinated spores. 12,282 transcripts were assembled from 454-pyrosequencing data and used as reference for digital gene expression analysis to compare the germinated uredinospores and haustoria transcriptomes based on Illumina RNAseq data. More than 400 genes encoding secreted proteins which constitute candidate effectors were identified from the haustorial transcriptome, with two thirds of these up-regulated in this tissue compared to germinated spores. RT-PCR analysis confirmed the expression patterns of 94 effector candidates. The analysis also revealed that spores rely mainly on stored energy reserves for growth and development, while haustoria take up host nutrients for massive energy production for biosynthetic pathways and the ultimate production of spores. Together, these studies substantially increase our knowledge of potential Pst effectors and provide new insights into the pathogenic strategies of this important organism.

 

Garnica DP, Upadhyaya NM, Dodds PN, Rathjen JP

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Genome Announcements: Several plant pathogen genomes published in the issue of May/June 2013; 1 (3

Draft Genome Sequence of Botrytis cinerea BcDW1, Inoculum for Noble Rot of Grape Berries

Barbara Blanco-Ulate, Greg Allen, Ann L. T. Powell, and Dario CantuGenome Announc. May/June 2013 1:e00252-13; doi:10.1128/genomeA.00252-13http://genomea.asm.org/content/1/3/e00252-13.abstract.html

 

Draft Genome Sequence of the Grapevine Dieback Fungus Eutypa lata UCR-EL1

Barbara Blanco-Ulate, Philippe E. Rolshausen, and Dario CantuGenome Announc. May/June 2013 1:e00228-13; doi:10.1128/genomeA.00228-13http://genomea.asm.org/content/1/3/e00228-13.abstract.html

 

Draft Genome Sequence of Neofusicoccum parvum Isolate UCR-NP2, a Fungal Vascular Pathogen Associated with Grapevine Cankers

Barbara Blanco-Ulate, Philippe Rolshausen, and Dario CantuGenome Announc. May/June 2013 1:e00339-13; doi:10.1128/genomeA.00339-13http://genomea.asm.org/content/1/3/e00339-13.abstract.html

 

Draft Genome Sequence of the Ascomycete Phaeoacremonium aleophilum Strain UCR-PA7, a Causal Agent of the Esca Disease Complex in Grapevines

Barbara Blanco-Ulate, Philippe Rolshausen, and Dario CantuGenome Announc. May/June 2013 1:e00390-13; doi:10.1128/genomeA.00390-13http://genomea.asm.org/content/1/3/e00390-13.abstract.html

 

Genome Sequencing of Ralstonia solanacearum FQY_4, Isolated from a Bacterial Wilt Nursery Used for Breeding Crop Resistance

Yi Cao, Baoyu Tian, Yanxia Liu, Liuti Cai, Hancheng Wang, Ning Lu, Maosheng Wang, Shenghua Shang, Zhengyou Luo, and Junxiong ShiGenome Announc. May/June 2013 1:e00125-13; doi:10.1128/genomeA.00125-13http://genomea.asm.org/content/1/3/e00125-13.abstract.html

 

Draft Genome Sequence of Erwinia toletana, a Bacterium Associated with Olive Knots Caused by Pseudomonas savastanoi pv. Savastanoi

Daniel Passos da Silva, Giulia Devescovi, Konrad Paszkiewicz, Chiaraluce Moretti, Roberto Buonaurio, David J. Studholme, and Vittorio VenturiGenome Announc. May/June 2013 1:e00205-13; doi:10.1128/genomeA.00205-13http://genomea.asm.org/content/1/3/e00205-13.abstract.html

 

Genome Sequences of Pseudomonas spp. Isolated from Cereal CropsDonald M. Gardiner, Jiri Stiller, Lorenzo Covarelli, Magdalen Lindeberg, Roger G. Shivas, and John M. MannersGenome Announc. May/June 2013 1:e00209-13; doi:10.1128/genomeA.00209-13http://genomea.asm.org/content/1/3/e00209-13.abstract.html

 

Complete Genome Sequence of Xanthomonas citri subsp. citri Strain Aw12879, a Restricted-Host-Range Citrus Canker-Causing Bacterium

Neha Jalan, Dibyendu Kumar, Fahong Yu, Jeffrey B. Jones, James H. Graham, and Nian WangGenome Announc. May/June 2013 1:e00235-13; doi:10.1128/genomeA.00235-13http://genomea.asm.org/content/1/3/e00235-13.abstract.html

 

Genome Sequence of Xanthomonas arboricola pv. Corylina, Isolated from Turkish Filbert in Colorado

Jorge Ibarra Caballero, Marcelo M. Zerillo, Jacob Snelling, Christina Boucher, and Ned TisseratGenome Announc. May/June 2013 1:e00246-13; doi:10.1128/genomeA.00246-13http://genomea.asm.org/content/1/3/e00246-13.abstract.html

 

Genome Sequence of the Banana Pathogen Dickeya zeae Strain MS1, Which Causes Bacterial Soft Rot

Jing-Xin Zhang, Bi-Run Lin, Hui-Fang Shen, and Xiao-Ming PuGenome Announc. May/June 2013 1:e00317-13; doi:10.1128/genomeA.00317-13http://genomea.asm.org/content/1/3/e00317-13.abstract.html

 

Genome Sequence of the Pectobacterium atrosepticum Strain CFBP6276, Causing Blackleg and Soft Rot Diseases on Potato Plants and Tubers

Anthony Kwasiborski, Samuel Mondy, Amélie Beury-Cirou, and Denis FaureGenome Announc. May/June 2013 1:e00374-13; doi:10.1128/genomeA.00374-13http://genomea.asm.org/content/1/3/e00374-13.abstract.html

 

Complete Genome Sequences of Two Sweet Potato Chlorotic Stunt Virus Isolates from China

Yanhong Qin, Zhenchen Zhang, Qi Qiao, Desheng Zhang, Yuting Tian, Yongjiang Wang, and Shuang WangGenome Announc. May/June 2013 1:e00218-13; doi:10.1128/genomeA.00218-13http://genomea.asm.org/content/1/3/e00218-13.abstract.html
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PLOS Pathogens: The Xanthomonas campestris Type III Effector XopJ Targets the Host Cell Proteasome to Suppress Salicylic-Acid Mediated Plant Defence

PLOS Pathogens: The Xanthomonas campestris Type III Effector XopJ Targets the Host Cell Proteasome to Suppress Salicylic-Acid Mediated Plant Defence | Effectors and Plant Immunity | Scoop.it

(via @SuayibUestuen, thanks!)

 

The phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv) requires type III effector proteins (T3Es) for virulence. After translocation into the host cell, T3Es are thought to interact with components of host immunity to suppress defence responses. XopJ is a T3E protein from Xcv that interferes with plant immune responses; however, its host cellular target is unknown. Here we show that XopJ interacts with the proteasomal subunit RPT6 in yeast andin planta to inhibit proteasome activity. A C235A mutation within the catalytic triad of XopJ as well as a G2A exchange within the N-terminal myristoylation motif abolishes the ability of XopJ to inhibit the proteasome. Xcv ΔxopJ mutants are impaired in growth and display accelerated symptom development including tissue necrosis on susceptible pepper leaves. Application of the proteasome inhibitor MG132 restored the ability of the Xcv ΔxopJ to attenuate the development of leaf necrosis. The XopJ dependent delay of tissue degeneration correlates with reduced levels of salicylic acid (SA) and changes in defence- and senescence-associated gene expression. Necrosis upon infection with Xcv ΔxopJ was greatly reduced in pepper plants with reduced expression of NPR1, a central regulator of SA responses, demonstrating the involvement of SA-signalling in the development of XopJ dependent phenotypes. Our results suggest that XopJ-mediated inhibition of the proteasome interferes with SA-dependent defence response to attenuate onset of necrosis and to alter host transcription. A central role of the proteasome in plant defence is discussed.

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Mol. Mic.: High-resolution transcriptional analysis of the regulatory influence of cell-to-cell signalling reveals novel genes that contribute to Xanthomonas phytopathogenesis (2013)

Mol. Mic.: High-resolution transcriptional analysis of the regulatory influence of cell-to-cell signalling reveals novel genes that contribute to Xanthomonas phytopathogenesis (2013) | Effectors and Plant Immunity | Scoop.it

The bacterium Xanthomonas campestris is an economically important pathogen of many crop species and a model for the study of bacterial phytopathogenesis. In X. campestris, a regulatory system mediated by the signal molecule DSF controls virulence to plants. The synthesis and recognition of the DSF signal depends upon different Rpf proteins. DSF signal generation requires RpfF whereas signal perception and transduction depends upon a system comprising the sensor RpfC and regulator RpfG. Here we have addressed the action and role of Rpf/DSF signalling in phytopathogenesis by high-resolution transcriptional analysis coupled to functional genomics. We detected transcripts for many genes that were unidentified by previous computational analysis of the genome sequence. Novel transcribed regions included intergenic transcripts predicted as coding or non-coding as well as those that were antisense to coding sequences. In total, mutation of rpfF, rpfG and rpfC led to alteration in transcript levels (more than fourfold) of approximately 480 genes. The regulatory influence of RpfF and RpfC demonstrated considerable overlap. Contrary to expectation, the regulatory influence of RpfC and RpfG had limited overlap, indicating complexities of the Rpf signalling system. Importantly, functional analysis revealed over 160 new virulence factors within the group of Rpf-regulated genes.

 

Shi-Qi An, Melanie Febrer, Yvonne McCarthy, Dong-Jie Tang, Leah Clissold, Gemy Kaithakottil, David Swarbreck, Ji-Liang Tang, Jane Rogers, J. Maxwell Dow, Robert P. Ryan

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New Hampshire (US): Agrilus planipennis found in 5% of trees in Concord

New Hampshire (US): Agrilus planipennis found in 5% of trees in Concord | Effectors and Plant Immunity | Scoop.it
New Hampshire forest officials say an invasive beetle that destroys ash trees has been found in about 5 percent of trees surveyed in central Concord.

Via Anne-Sophie Roy
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Anne-Sophie Roy's curator insight, June 3, 2013 4:40 AM

Surveys on Agrilus planipennis are continuing in New Hampshire (US).