Publications from...
Follow
Find
9.0K views | +1 today
 
Scooped by The Sainsbury Lab
onto Publications from The Sainsbury Laboratory
Scoop.it!

BMC Plant Biology: Defining the full tomato NB-LRR resistance gene repertoire using genomic and cDNA RenSeq (2014)

BMC Plant Biology: Defining the full tomato NB-LRR resistance gene repertoire using genomic and cDNA RenSeq (2014) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

The availability of draft crop plant genomes allows the prediction of the full complement of genes that encode NB-LRR resistance gene homologs, enabling a more targeted breeding for disease resistance. Recently, we developed the RenSeq method to reannotate the full NB-LRR gene complement in potato and to identify novel sequences that were not picked up by the automated gene prediction software. Here, we established RenSeq on the reference genome of tomato (Solanum lycopersicum) Heinz 1706, using 260 previously identified NB-LRR genes in an updated Solanaceae RenSeq bait library.

Result: Using 250-bp MiSeq reads after RenSeq on genomic DNA of Heinz 1706, we identified 105 novel NB-LRR sequences. Reannotation included the splitting of gene models, combination of partial genes to a longer sequence and closing of assembly gaps. Within the draft S. pimpinellifolium LA1589 genome, RenSeq enabled the annotation of 355 NB-LRR genes. The majority of these are however fragmented, with 5[prime]- and 3[prime]-end located on the edges of separate contigs. Phylogenetic analyses show a high conservation of all NB-LRR classes between Heinz 1706, LA1589 and the potato clone DM, suggesting that all sub-families were already present in the last common ancestor. A phylogenetic comparison to the Arabidopsis thaliana NB-LRR complement verifies the high conservation of the more ancient CCRPW8-type NB-LRRs. Use of RenSeq on cDNA from uninfected and late blight-infected tomato leaves allows the avoidance of sequence analysis of non-expressed paralogues.

more...
No comment yet.
Publications from The Sainsbury Laboratory
Your new post is loading...
Your new post is loading...
Scooped by The Sainsbury Lab
Scoop.it!

PLoS One: Heterologous Expression Screens in Nicotiana benthamiana Identify a Candidate Effector of the Wheat Yellow Rust Pathogen that Associates with Processing Bodies (2016)

PLoS One: Heterologous Expression Screens in  Nicotiana benthamiana  Identify a Candidate Effector of the Wheat Yellow Rust Pathogen that Associates with Processing Bodies (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Rust fungal pathogens of wheat (Triticum spp.) affect crop yields worldwide. The molecular mechanisms underlying the virulence of these pathogens remain elusive, due to the limited availability of suitable molecular genetic research tools. Notably, the inability to perform high-throughput analyses of candidate virulence proteins (also known as effectors) impairs progress. We previously established a pipeline for the fast-forward screens of rust fungal candidate effectors in the model plant Nicotiana benthamiana. This pipeline involves selecting candidate effectors in silico and performing cell biology and protein-protein interaction assays in planta to gain insight into the putative functions of candidate effectors. In this study, we used this pipeline to identify and characterize sixteen candidate effectors from the wheat yellow rust fungal pathogen Puccinia striiformis f sp tritici. Nine candidate effectors targeted a specific plant subcellular compartment or protein complex, providing valuable information on their putative functions in plant cells. One candidate effector, PST02549, accumulated in processing bodies (P-bodies), protein complexes involved in mRNA decapping, degradation, and storage. PST02549 also associates with the P-body-resident ENHANCER OF mRNA DECAPPING PROTEIN 4 (EDC4) from N. benthamiana and wheat. We propose that P-bodies are a novel plant cell compartment targeted by pathogen effectors.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

bioRxiv: Cell re-entry assays do not support models of pathogen-independent translocation of AvrM and AVR3a effectors into plant cells (2016)

bioRxiv: Cell re-entry assays do not support models of pathogen-independent translocation of AvrM and AVR3a effectors into plant cells (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

The cell re-entry assay is widely used to evaluate pathogen effector protein uptake into plant cells. The assay is based on the premise that effector proteins secreted out of a leaf cell would translocate back into the cytosol of the same cell via a yet unknown host-derived uptake mechanism. Here, we critically assess this assay by expressing domains of the effector proteins AvrM-A of Melampsora lini and AVR3a of Phytophthora infestans fused to a signal peptide and fluorescent proteins in Nicotiana benthamiana. We found that the secreted fusion proteins do not re-enter plant cells from the apoplast and that the assay is prone to false-positives. We therefore emit a cautionary note on the use of the cell re-entry assay for protein trafficking studies.

more...
The Pub Club's curator insight, February 1, 10:11 AM

From our friends at TSL...

Scooped by The Sainsbury Lab
Scoop.it!

BMC Plant Biology: Altered glycosylation of exported proteins, including surface immune receptors, compromises calcium and downstream signaling responses to microbe-associated molecular patterns in...

BMC Plant Biology: Altered glycosylation of exported proteins, including surface immune receptors, compromises calcium and downstream signaling responses to microbe-associated molecular patterns in... | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Calcium, as a second messenger, transduces extracellular signals into cellular reactions. A rise in cytosolic calcium concentration is one of the first plant responses after exposure to microbe-associated molecular patterns (MAMPs). We reported previously the isolation of Arabidopsis thaliana mutants with a “changed calcium elevation” (cce) response to flg22, a 22-amino-acid MAMP derived from bacterial flagellin.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Frontiers: The poplar Rust-Induced Secreted Protein (RISP) inhibits the growth of the leaf rust pathogen Melampsora larici-populina and triggers cell culture alkalinisation (2016)

Frontiers: The poplar Rust-Induced Secreted Protein (RISP) inhibits the growth of the leaf rust pathogen Melampsora larici-populina and triggers cell culture alkalinisation (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Plant cells secrete a wide range of proteins in extracellular spaces in response to pathogen attack. The poplar Rust-Induced Secreted Protein (RISP) is a small cationic protein of unknown function that was identified as the most induced gene in poplar leaves during immune responses to the leaf rust pathogen Melampsora larici-populina, an obligate biotrophic parasite. Here, we combined in planta and in vitro molecular biology approaches to tackle the function of RISP. Using a RISP-mCherry fusion transiently expressed in Nicotiana benthamiana leaves, we demonstrated that RISP is secreted into the apoplast. A recombinant RISP specifically binds to M. larici-populina urediniospores and inhibits their germination. It also arrests the growth of the fungus in vitro and on poplar leaves. Interestingly, RISP also triggers poplar cell culture alkalinisation and is cleaved at the C-terminus by a plant-encoded mechanism. Altogether our results indicate that RISP is an antifungal protein that has the ability to trigger cellular responses.

more...
Jim Alfano's curator insight, January 27, 8:18 AM

Is it secreted when other types of pathogens attack? That is, is it a typical PR protein?

Scooped by The Sainsbury Lab
Scoop.it!

PNAS: PP2A-3 interacts with ACR4 and regulates formative cell division in the Arabidopsis root (2016)

PNAS: PP2A-3 interacts with ACR4 and regulates formative cell division in the Arabidopsis root (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Plant growth and development are mediated through a wide range of proteins, including receptor kinases and phosphatases. The receptor kinase ARABIDOPSIS CRINKLY 4 (ACR4) is part of a mechanism controlling formative cell divisions in the Arabidopsis root. However, the regulation of ACR4 signaling and how it affects cell divisions remains completely unknown. We discovered that ACR4 phosphorylates the PROTEIN PHOSPHATASE 2A-3 (PP2A-3) catalytic subunit of the PP2A phosphatase holoenzyme and that PP2A dephosphorylates ACR4. These data exposed a tightly regulated point in the associated biochemical network regulating formative cell divisions in plant roots.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

eLife: An effector of the Irish potato famine pathogen antagonizes a host autophagy cargo receptor (2016)

eLife: An effector of the Irish potato famine pathogen antagonizes a host autophagy cargo receptor (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Plants use autophagy to safeguard against infectious diseases. However, how plant pathogens interfere with autophagy related processes is unknown. Here we show that PexRD54, an effector from the Irish potato famine pathogen Phytophthora infestans, binds host autophagy protein ATG8CL to stimulate autophagosome formation. PexRD54 depletes the autophagy cargo receptor Joka2 out of ATG8CL complexes and interferes with Joka2's positive effect on pathogen defense. Thus a plant pathogen effector has evolved to antagonize a host autophagy cargo receptor in order to counteract host defenses. - See more at: http://elifesciences.org/content/early/2016/01/14/eLife.10856#sthash.R6yA1fGD.dpuf

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Theor Appl Genet: Isolation and fine mapping of Rps6: an intermediate host resistance gene in barley to wheat stripe rust (2016)

Theor Appl Genet: Isolation and fine mapping of Rps6: an intermediate host resistance gene in barley to wheat stripe rust (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:
Key message

We uncouple host and nonhost resistance in barley to Puccinia striiformis ff. spp. hordei andtritici . We isolate, fine map, and physically anchor Rps6 to chromosome 7H in barley.

Abstract

A plant may be considered a nonhost of a pathogen if all known genotypes of a plant species are resistant to all known isolates of a pathogen species. However, if a small number of genotypes are susceptible to some known isolates of a pathogen species this plant may be considered an intermediate host. Barley (Hordeum vulgare) is an intermediate host for Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust. We wanted to understand the genetic architecture underlying resistance to Pst and to determine whether any overlap exists with resistance to the host pathogen, Puccinia striiformis f. sp. hordei (Psh). We mapped Pst resistance to chromosome 7H and show that host and intermediate host resistance is genetically uncoupled. Therefore, we designate this resistance locus Rps6. We used phenotypic and genotypic selection on F2:3 families to isolate Rps6 and fine mapped the locus to a 0.1 cM region. Anchoring of the Rps6 locus to the barley physical map placed the region on a single fingerprinted contig spanning a physical region of 267 kb. Efforts are now underway to sequence the minimal tiling path and to delimit the physical region harboring Rps6. This will facilitate additional marker development and permit identification of candidate genes in the region.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Plant Cell: Immobilized subpopulations of leaf epidermal mitochondria mediate PEN2-dependent pathogen entry control in Arabidopsis (2015)

Plant Cell: Immobilized subpopulations of leaf epidermal mitochondria mediate PEN2-dependent pathogen entry control in Arabidopsis (2015) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

The atypical myrosinase PEN2 is required for broad-spectrum invasion resistance to filamentous plant pathogens. Previous localization studies suggested PEN2-GFP association with peroxisomes. Here we show that PEN2 is a tail-anchored protein with dual-membrane targeting to peroxisomes and mitochondria and that PEN2 has the capacity to form homo-oligomer complexes. We demonstrate pathogen-induced recruitment and immobilization of mitochondrial subpopulations at sites of attempted fungal invasion and show that mitochondrial arrest is accompanied by peripheral accumulation of GFP-tagged PEN2. PEN2 substrate production by the cytochrome P450 monooxygenase CYP81F2 is localized to the surface of the Endoplasmic Reticulum which focally reorganizes close to the immobilized mitochondria. Exclusive targeting of PEN2 to the outer membrane of mitochondria complements the pen2 mutant phenotype corroborating the functional importance of the mitochondrial PEN2 protein subpool for controlled local production of PEN2 hydrolysis products at subcellular plant-microbe interaction domains. Moreover, live cell imaging shows that mitochondria arrested at these domains exhibit a pathogen-induced redox imbalance which may lead to production of intracellular signals.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Cell Host & Microbe: Fungal Sex Receptors Recalibrated to Detect Host Plants (2015)

Cell Host & Microbe: Fungal Sex Receptors Recalibrated to Detect Host Plants (2015) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Secreted peroxidases are well-known components of damage-induced defense responses in plants. A recent study in Nature ( Turrà et al., 2015) has revealed that these enzymes can inadvertently serve as reporters of wounded sites and constitute an “Achilles heel,” allowing adapted pathogens to track and enter host tissue.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Genome Biology: Induction of targeted, heritable mutations in barley and Brassica oleracea using RNA-guided Cas9 nuclease (2015)

Genome Biology: Induction of targeted, heritable mutations in barley and Brassica oleracea using RNA-guided Cas9 nuclease (2015) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

The RNA-guided Cas9 system represents a flexible approach for genome editing in plants. This method can create specific mutations that knock-out or alter target gene function. It provides a valuable tool for plant research and offers opportunities for crop improvement.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Methods Mol Biol: Immunoprecipitation of Plasma Membrane Receptor-Like Kinases for Identification of Phosphorylation Sites and Associated Proteins (2015)

Methods Mol Biol: Immunoprecipitation of Plasma Membrane Receptor-Like Kinases for Identification of Phosphorylation Sites and Associated Proteins (2015) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Membrane proteins are difficult to study for numerous reasons. The surface of membrane proteins is relatively hydrophobic and sometimes very unstable, additionally requiring detergents for their extraction from the membrane. This leads to challenges at all levels, including expression, solubilization, purification, identification of associated proteins, and the identification of post-translational modifications. However, recent advances in immunoprecipitation technology allow to isolate membrane proteins efficiently, facilitating the study of protein-protein interactions, the identification of novel associated proteins, and to identify post-translational modifications, such as phosphorylation. Here, we describe an optimized immunoprecipitation protocol for plant plasma membrane receptor-like kinases.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Genome Biology: Boosting plant immunity with CRISPR/Cas (2015)

Genome Biology: Boosting plant immunity with CRISPR/Cas (2015) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

CRISPR/Cas has recently been transferred to plants to make them resistant to geminiviruses, a damaging family of DNA viruses. We discuss the potential and the limitations of this method.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Front. Plant Sci.: Flg22-Triggered Immunity Negatively Regulates Key BR Biosynthetic Genes (2015)

Front. Plant Sci.: Flg22-Triggered Immunity Negatively Regulates Key BR Biosynthetic Genes (2015) | Publications from The Sainsbury Laboratory | Scoop.it
In plants, activation of growth and activation of immunity are opposing processes that define a trade-off. In the past few years, the growth-promoting hormones brassinosteroids (BR) have emerged as negative regulators of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI), promoting growth at the expense of defence. The crosstalk between BR and PTI signalling was described as negative and unidirectional, since activation of PTI does not affect several analysed steps in the BR signalling pathway. In this work, we describe that activation of PTI by the bacterial PAMP flg22 results in the reduced expression of BR biosynthetic genes. This effect does not require BR perception or signalling, and occurs within 15 minutes of flg22 treatment. Since the described PTI-induced repression of gene expression may result in a reduction in BR biosynthesis, the crosstalk between PTI and BR could actually be negative and bidirectional, a possibility that should be taken into account when considering the interaction between these two pathways.
more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

PLoS Genetics: Adaptive Remodeling of the Bacterial Proteome by Specific Ribosomal Modification Regulates Pseudomonas Infection and Niche Colonisation (2016)

PLoS Genetics: Adaptive Remodeling of the Bacterial Proteome by Specific Ribosomal Modification Regulates  Pseudomonas  Infection and Niche Colonisation (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Post-transcriptional control of protein abundance is a highly important, underexplored regulatory process by which organisms respond to their environments. Here we describe an important and previously unidentified regulatory pathway involving the ribosomal modification protein RimK, its regulator proteins RimA and RimB, and the widespread bacterial second messenger cyclic-di-GMP (cdG). Disruption of rimK affects motility and surface attachment in pathogenic and commensal Pseudomonas species, with rimK deletion significantly compromising rhizosphere colonisation by the commensal soil bacterium P. fluorescens, and plant infection by the pathogens P. syringae and P. aeruginosa. RimK functions as an ATP-dependent glutamyl ligase, adding glutamate residues to the C-terminus of ribosomal protein RpsF and inducing specific effects on both ribosome protein complement and function. Deletion of rimK in P. fluorescens leads to markedly reduced levels of multiple ribosomal proteins, and also of the key translational regulator Hfq. In turn, reduced Hfq levels induce specific downstream proteomic changes, with significant increases in multiple ABC transporters, stress response proteins and non-ribosomal peptide synthetases seen for both ΔrimK and Δhfqmutants. The activity of RimK is itself controlled by interactions with RimA, RimB and cdG. We propose that control of RimK activity represents a novel regulatory mechanism that dynamically influences interactions between bacteria and their hosts; translating environmental pressures into dynamic ribosomal changes, and consequently to an adaptive remodeling of the bacterial proteome.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Plant Methods: Meeting report: GARNet/OpenPlant CRISPR-Cas workshop (2016)

Plant Methods: Meeting report: GARNet/OpenPlant CRISPR-Cas workshop (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Targeted genome engineering has been described as a “game-changing technology” for fields as diverse as human genetics and plant biotechnology. One technique used for precise gene editing utilises the CRISPR-Cas system and is an effective method for genetic engineering in a wide variety of plants. However, many researchers remain unaware of both the technical challenges that emerge when using this technique or of its potential benefits. Therefore in September 2015, GARNet and OpenPlant organized a two-day workshop at the John Innes Centre that provided both background information and hands-on training for this important technology.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

BBA: Biochemical characterization of the tomato phosphatidylinositol-specific phospholipase C (PI-PLC) family and its role in plant immunity (2016)

BBA: Biochemical characterization of the tomato phosphatidylinositol-specific phospholipase C (PI-PLC) family and its role in plant immunity (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:
Highlights

Seven genes encoding PLCs form tomato were identified.

 

Recombinant tomato PLC proteins showed typical PLC activity.

Tomato PLC2, PLC4 and PLC5 showed distinct requirements for Ca2 + ions and the pH.

The activity of each tomato PLC enzyme is probably differentially regulated in vivo.

The response to flg22 and FLS2 endocytosis are supressed by inhibition of PLC activity.

Abstract

Plants possess effective mechanisms to quickly respond to biotic and abiotic stresses. The rapid activation of Phosphatidylinositol-specific Phospholipase C (PLC) enzymes occurs early after the stimulation of plant immune-receptors. Genomes of different plant species encode multiple PLC homologs belonging to one class, PLCζ. Here we determined whether all tomato homologs encode active enzymes and whether they can generate signals that are distinct from one another. We searched the recently completed tomato (Solanum lycopersicum) genome sequence and identified a total of seven PLCs. Recombinant proteins were produced for all tomato PLCs, except for SlPLC7. The purified proteins showed typical PLC activity, as different PLC substrates were hydrolysed to produce diacylglycerol. We studied SlPLC2, SlPLC4 and SlPLC5 enzymes in more detail and observed distinct requirements for Ca2 + ions and pH, for both their optimum activity and substrate preference. This indicates that each enzyme could be differentially and specifically regulated in vivo, leading to the generation of PLC homolog-specific signals in response to different stimuli. PLC overexpression and specific inhibition of PLC activity revealed that PLC is required for both specific effector- and more general “pattern”-triggered immunity. For the latter, we found that both the flagellin-triggered response and the internalization of the corresponding receptor, Flagellin Sensing 2 (FLS2) of Arabidopsis thaliana, is supressed by inhibition of PLC activity. Altogether, our data support an important role for PLC enzymes in plant defence signalling downstream of immune receptors.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

J Exp Bot: The Arabidopsis NADPH oxidases RbohD and RbohF display differential expression patterns and contributions during plant immunity (2016)

J Exp Bot: The Arabidopsis NADPH oxidases RbohD and RbohF display differential expression patterns and contributions during plant immunity (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Plant NADPH oxidases, also known as respiratory burst oxidase homologues (RBOHs), produce reactive oxygen species (ROS) that perform a wide range of functions. RbohD and RbohF, two of the 10 Rboh genes present in Arabidopsis, are pleiotropic and mediate diverse physiological processes including the response to pathogens. We hypothesized that the spatio-temporal control of RbohD and RbohF gene expression might be critical in determining their multiplicity of functions. Transgenic Arabidopsis plants with RbohD and RbohF promoter fusions to β-glucuronidase and Luciferase reporter genes were generated. Analysis of these plants revealed a differential expression pattern for RbohD and RbohF throughout plant development and during immune responses. RbohD and RbohF gene expression was differentially modulated by pathogen-associated molecular patterns. Histochemical stains and in vivoexpression analysis showed a correlation between the level of RbohD and RbohF promoter activity, H2O2 accumulation and the amount of cell death in response to the pathogenic bacterium Pseudomonas syringae pv. tomato DC3000 and the necrotrophic fungus Plectosphaerella cucumerina. A promoter-swap strategy revealed that the promoter region of RbohDwas required to drive production of ROS by this gene in response to pathogens. Moreover, RbohD promoter was activated during Arabidopsis interaction with a non-virulent P. cucumerina isolate, and susceptibility tests with the double mutant rbohD rbohF uncovered a new function for these oxidases in basal resistance. Altogether, our results suggest that differential spatio-temporal expression of the Rboh genes contributes to fine-tune RBOH/NADPH oxidase-dependent ROS production and signaling in Arabidopsis immunity.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

EMBO Reports: Attenuation of pattern recognition receptor signaling is mediated by a MAP kinase kinase kinase (2016)

EMBO Reports: Attenuation of pattern recognition receptor signaling is mediated by a MAP kinase kinase kinase (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Pattern recognition receptors (PRRs) play a key role in plant and animal innate immunity. PRR binding of their cognate ligand triggers a signaling network and activates an immune response. Activation of PRR signaling must be controlled prior to ligand binding to prevent spurious signaling and immune activation. Flagellin perception in Arabidopsis through FLAGELLIN‐SENSITIVE 2 (FLS2) induces the activation of mitogen‐activated protein kinases (MAPKs) and immunity. However, the precise molecular mechanism that connects activated FLS2 to downstream MAPK cascades remains unknown. Here, we report the identification of a differentially phosphorylated MAP kinase kinase kinase that also interacts with FLS2. Using targeted proteomics and functional analysis, we show that MKKK7 negatively regulates flagellin‐triggered signaling and basal immunity and this requires phosphorylation of MKKK7 on specific serine residues. MKKK7 attenuates MPK6 activity and defense gene expression. Moreover, MKKK7 suppresses the reactive oxygen species burst downstream of FLS2, suggesting that MKKK7‐mediated attenuation of FLS2 signaling occurs through direct modulation of the FLS2 complex.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

New Phyt: Avr4 promotes Cf-4 receptor-like protein association with the BAK1/SERK3 receptor-like kinase to initiate receptor endocytosis and plant immunity (2016)

New Phyt: Avr4 promotes Cf-4 receptor-like protein association with the BAK1/SERK3 receptor-like kinase to initiate receptor endocytosis and plant immunity (2016) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:
The first layer of plant immunity is activated by cell surface receptor-like kinases (RLKs) and proteins (RLPs) that detect infectious pathogens. Constitutive interaction with the SUPPRESSOR OF BIR1 (SOBIR1) RLK contributes to RLP stability and kinase activity. As RLK activation requires transphosphorylation with a second associated RLK, it remains elusive how RLPs initiate downstream signaling.We employed live-cell imaging, gene silencing and coimmunoprecipitation to investigate the requirement of associated kinases for functioning and ligand-induced subcellular trafficking of Cf RLPs that mediate immunity of tomato against Cladosporium fulvum.Our research shows that after elicitation with matching effector ligands Avr4 and Avr9, BRI1-ASSOCIATED KINASE 1/SOMATIC EMBRYOGENESIS RECEPTOR KINASE 3 (BAK1/SERK3) associates with Cf-4 and Cf-9. BAK1/SERK3 is required for the effector-triggered hypersensitive response and resistance of tomato against C. fulvum. Furthermore, Cf-4 interacts with SOBIR1 at the plasma membrane and is recruited to late endosomes upon Avr4 trigger, also depending on BAK1/SERK3.These observations indicate that RLP-mediated resistance and endocytosis require ligand-induced recruitment of BAK1/SERK3, reminiscent of BAK1/SERK3 interaction and subcellular fate of the FLAGELLIN SENSING 2 (FLS2) RLK. This reveals that diverse classes of cell surface immune receptors share common requirements for initiation of resistance and endocytosis.
more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

bioRxiv: Arabidopsis late blight: Infection of a nonhost plant by Albugo laibachii enables full colonization by Phytophthora infestans (2015)

bioRxiv: Arabidopsis late blight: Infection of a nonhost plant by Albugo laibachii enables full colonization by Phytophthora infestans (2015) | Publications from The Sainsbury Laboratory | Scoop.it
bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution
The Sainsbury Lab's insight:

The oomycete pathogen Phytophthora infestans causes potato late blight, and as a potato and tomato specialist pathogen, is seemingly poorly adapted to infect plants outside the Solanaceae. Here, we report the unexpected finding that P. infestans can infect Arabidopsis thaliana when another oomycete pathogen, Albugo laibachii, has colonized the host plant. The behaviour and speed of P. infestans infection in Arabidopsis pre-infected with A. laibachii resemble P. infestans infection of susceptible potato plants. Transcriptional profiling of P. infestans genes during infection revealed a significant overlap in the sets of secreted-protein genes that are induced in P. infestans upon colonisation of potato and susceptible Arabidopsis, suggesting major similarities in P. infestans gene expression dynamics on the two plant species. Furthermore, we found haustoria of A. laibachii and P. infestanswithin in the same Arabidopsis cells. This Arabidopsis - A. laibachii - P. infestanstripartite interaction opens up various possibilities to dissect the molecular mechanisms of P. infestans infection and the processes occurring in co-infected Arabidopsis cells.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Curr Opin Biotechnol: Multi-gene engineering in plants with RNA-guided Cas9 nuclease (2015)

Curr Opin Biotechnol: Multi-gene engineering in plants with RNA-guided Cas9 nuclease (2015) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

The use of RNA-guided Cas9 endonuclease for the concurrent engineering of multiple genes has been demonstrated in a number of plant species. Although Cas9 is a large monomeric protein, the single guide RNA (sgRNA) that directs it to a specific DNA target sequence is small and easy to reprogram. It is therefore relatively simple to produce numerous sgRNAs to target multiple endogenous sequences. Several approaches to express multiple sgRNAs and Cas9 in plants for the purpose of simultaneous editing or transcriptional regulation of many genes have recently been reported.

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

New Phyt: The apoplast as battleground for plant–microbe interactions (2015)

New Phyt: The apoplast as battleground for plant–microbe interactions (2015) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:
12th New Phytologist Workshop in Castle Rauischholzhausen, Germany, July 2015

The plant apoplast is the compartment where the compatibility of plant–microbe interactions is initially determined, and compared to cytoplasmic immune events, the molecular mechanisms occurring within the apoplast are poorly understood. Whether or not a pathogen can accommodate itself in its host tissue is decided during the initial phase of infection. At this stage, the plant immune system recognizes conserved molecular patterns of the invading microbe through surface-localized pattern recognition receptors (PRRs) to initiate pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). Additionally, pathogens deploy a broad arsenal of virulence factors that aim to disarm PTI by targeting immune receptors and other signaling components. In turn, these effectors can also be recognized by the plant, inducing a second layer of immunity called effector-triggered immunity (ETI) (Jones & Dangl, 2006).

more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

New Phytologist: Helper NLR proteins NRC2a/b and NRC3 but not NRC1 are required for Pto-mediated cell death and resistance in Nicotiana benthamiana - Wu (2015)

New Phytologist: Helper NLR proteins NRC2a/b and NRC3 but not NRC1 are required for Pto-mediated cell death and resistance in Nicotiana benthamiana - Wu (2015) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Plants defend against pathogens using both cell surface and intracellular immune receptors (Dodds & Rathjen, 2010; Win et al., 2012). Plant cell surface receptors include receptor-like kinases (RLKs) and receptor-like proteins (RLPs), which respond to pathogen-derived apoplastic molecules (Boller & Felix, 2009; Thomma et al., 2011). By contrast, plant intracellular immune receptors are typically nucleotide-binding leucine-rich repeat (NB-LRR or NLR) proteins, which respond to translocated effectors from a diversity of pathogens (Eitas & Dangl, 2010; Bonardi et al., 2012). These receptors engage in microbial perception either by directly binding pathogen molecules or indirectly by sensing pathogen-induced perturbations (Win et al., 2012). However, signaling events downstream of pathogen recognition remain poorly understood.

more...
No comment yet.
Rescooped by The Sainsbury Lab from Publications
Scoop.it!

bioRxiv: In planta expression screens of candidate effector proteins from the wheat yellow rust fungus reveal processing bodies as a pathogen-targeted plant cell compartment (2015)

bioRxiv: In planta expression screens of candidate effector proteins from the wheat yellow rust fungus reveal processing bodies as a pathogen-targeted plant cell compartment (2015) | Publications from The Sainsbury Laboratory | Scoop.it

Rust fungal pathogens of wheat (Triticum spp.) affect crop yields worldwide. The molecular mechanisms underlying the virulence of these pathogens remain elusive, due to the limited availability of suitable molecular genetic research tools. Notably, the inability to perform high-throughput analyses of candidate virulence proteins (also known as effectors) impairs progress. We previously established a pipeline for the fast-forward screens of rust fungal effectors in the model plant Nicotiana benthamiana. This pipeline involves selecting candidate effectors in silico and performing cell biology and protein-protein interaction assays in planta to gain insight into the putative functions of candidate effectors. In this study, we used this pipeline to identify and characterize sixteen candidate effectors from the wheat yellow rust fungal pathogen Puccinia striiformis f sp tritici. Nine candidate effectors targeted a specific plant subcellular compartment or protein complex, providing valuable information on their putative functions in plant cells. One candidate effector, PST02549, accumulated in processing bodies (P-bodies), protein complexes involved in mRNA decapping, degradation, and storage. PST02549 also associates with the P-body-resident ENHANCER OF mRNA DECAPPING PROTEIN 4 (EDC4) from N. benthamiana and wheat. Our work identifies P-bodies as a novel plant cell compartment targeted by pathogen effectors.


Via Kamoun Lab @ TSL
more...
No comment yet.
Scooped by The Sainsbury Lab
Scoop.it!

Plant Cell: Septin-Dependent Assembly of the Exocyst Is Essential for Plant Infection by Magnaporthe oryzae (2015)

Plant Cell: Septin-Dependent Assembly of the Exocyst Is Essential for Plant Infection by Magnaporthe oryzae (2015) | Publications from The Sainsbury Laboratory | Scoop.it
The Sainsbury Lab's insight:

Magnaporthe oryzae is the causal agent of rice blast disease, the most devastating disease of cultivated rice (Oryza sativa) and a continuing threat to global food security. To cause disease, the fungus elaborates a specialized infection cell called an appressorium, which breaches the cuticle of the rice leaf, allowing the fungus entry to plant tissue. Here, we show that the exocyst complex localizes to the tips of growing hyphae during vegetative growth, ahead of the Spitzenkörper, and is required for polarized exocytosis. However, during infection-related development, the exocyst specifically assembles in the appressorium at the point of plant infection. The exocyst components Sec3, Sec5, Sec6, Sec8, and Sec15, and exocyst complex proteins Exo70 and Exo84 localize specifically in a ring formation at the appressorium pore. Targeted gene deletion, or conditional mutation, of genes encoding exocyst components leads to impaired plant infection. We demonstrate that organization of the exocyst complex at the appressorium pore is a septin-dependent process, which also requires regulated synthesis of reactive oxygen species by the NoxR-dependent Nox2 NADPH oxidase complex. We conclude that septin-mediated assembly of the exocyst is necessary for appressorium repolarization and host cell invasion.

more...
No comment yet.