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Plant Cell: Spatio-Temporal Cellular Dynamics of the Arabidopsis Flagellin Receptor Reveal Activation Status-Dependent Endosomal Sorting (2012)

Plant Cell: Spatio-Temporal Cellular Dynamics of the Arabidopsis Flagellin Receptor Reveal Activation Status-Dependent Endosomal Sorting (2012) | Plants and Microbes | Scoop.it

The activity of surface receptors is location specific, dependent upon the dynamic membrane trafficking network and receptor-mediated endocytosis (RME). Therefore, the spatio-temporal dynamics of RME are critical to receptor function. The plasma membrane receptor FLAGELLIN SENSING2 (FLS2) confers immunity against bacterial infection through perception of flagellin (flg22). Following elicitation, FLS2 is internalized into vesicles. To resolve FLS2 trafficking, we exploited quantitative confocal imaging for colocalization studies and chemical interference. FLS2 localizes to bona fide endosomes via two distinct endocytic trafficking routes depending on its activation status. FLS2 receptors constitutively recycle in a Brefeldin A (BFA)–sensitive manner, while flg22-activated receptors traffic via ARA7/Rab F2b– and ARA6/Rab F1–positive endosomes insensitive to BFA. FLS2 endocytosis required a functional Rab5 GTPase pathway as revealed by dominant-negative ARA7/Rab F2b. Flg22-induced FLS2 endosomal numbers were increased by Concanamycin A treatment but reduced by Wortmannin, indicating that activated FLS2 receptors are targeted to late endosomes. RME inhibitors Tyrphostin A23 and Endosidin 1 altered but did not block induced FLS2 endocytosis. Additional inhibitor studies imply the involvement of the actin-myosin system in FLS2 internalization and trafficking. Altogether, we report a dynamic pattern of subcellular trafficking for FLS2 and reveal a defined framework for ligand-dependent endocytosis of this receptor.

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Storify: #MPMI2014 Day 5 of XVI IC-MPMI, Rhodes, Greece, 6-10 July

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Storify: #MPMI2014 Day 3 of XVI IC-MPMI, Rhodes, Greece, 6-10 July

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Jean-Michel Ané's curator insight, July 9, 8:27 AM

I am so disappointed to miss this conference...

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Storify Archive of #OMGN14 Oomycete Molecular Genetics Network Annual Meeting, Norwich, UK, July 2-4 2014

Tweets from the Oomycete Molecular Genetics Network Annual Meeting, Norwich, UK, July 2-4 2014 http://omgn.org
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Plant J: Powdery mildew resistance gene Pm8 derived from rye is suppressed by its wheat ortholog Pm3 (2014)

Plant J: Powdery mildew resistance gene Pm8 derived from rye is suppressed by its wheat ortholog Pm3 (2014) | Plants and Microbes | Scoop.it

The powdery mildew resistance gene Pm8 derived from rye is located on a 1BL.1RS chromosome translocation in wheat. However, some wheat lines with this translocation do not show resistance to isolates of the wheat powdery mildew pathogen avirulent to Pm8 due to an unknown genetically dominant suppression mechanism. Here we show that lines with suppressed Pm8 activity contain an intact and expressedPm8 gene. Therefore, the absence of Pm8 function in certain 1BL.1RS containing wheat lines is not the result of gene loss or mutation but is based on suppression. The wheat gene Pm3, an ortholog of rye Pm8, suppressed Pm8-mediated mildew resistance in lines containing Pm8 in a transient single-cell expression assay. This result was further confirmed in transgenic lines with combined Pm8 and Pm3 transgenes. Expression analysis revealed that suppression is not the result of gene silencing, either in wheat 1BL.1RS translocation lines carrying Pm8 or in transgenic genotypes with both Pm8 and Pm3 alleles. In addition, a similar abundance of the PM8 and PM3 proteins in single or double homozygous transgenic lines suggested that a post-translational mechanism is involved in Pm8 suppression. Co-expression of Pm8 and Pm3genes in N. benthamiana leaves followed by co-immunoprecipitation analysis showed that the two proteins interact. Therefore, the formation of a heteromeric protein complex might result in inefficient or absent signal transmission for defense reaction. These data provide a molecular explanation for resistance gene suppression in certain genetic backgrounds and suggest ways to circumvent it in future plant breeding.

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PBS: The next Green Revolution may rely on microbes (2014)

PBS: The next Green Revolution may rely on microbes (2014) | Plants and Microbes | Scoop.it

Ian Sanders wants to feed the world. A soft-spoken Brit, Sanders studies fungus genetics in a lab at the University of Lausanne in Switzerland. But fear not, he’s not on a mad-scientist quest to get the world to eat protein pastes made from ground-up fungi. Still, he believes—he’s sure—that these microbes will be critical to meeting the world’s future food needs.


Sanders’s eyes widen with delight and almost childlike glee when he talks about a microscopic life form called mycorrhizal fungus, his chosen lifetime research subject. Mycorrhizal fungi live in a tightly wound, mutually beneficial embrace with most plants on the planet. Years of dedication have made Sanders into one of the world’s foremost experts on the genetics of the microbe, and he recently was part of a team that sequenced the first mycorrhizal fungi genome.


Despite his drive, Sanders comes across as light-hearted as he teases and jokes with fellow researchers. But he loses his affable smile as he fires off facts about the upcoming food shortage: The world’s population is expected to increase to between 9 billion and 16 billion people. Five million people per year die of direct causes of malnutrition. Three and a half million of those are children under five. Today, we have the means to grow enough food to feed all those people, but we will most certainly need to produce more in the very near future.


Sanders may have come up with a way to do just that. He has successfully bred custom varieties of microbes that can help plants produce more food. It’s one of the ultimate goals of farming research—more food with, he hopes, little or no environmental downside.


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Plant J: The powdery mildew resistance protein RPW8.2 is carried on VAMP721/722 vesicles to the extrahaustorial membrane of haustorial complexes (2014)

Plant J: The powdery mildew resistance protein RPW8.2 is carried on VAMP721/722 vesicles to the extrahaustorial membrane of haustorial complexes (2014) | Plants and Microbes | Scoop.it

Plants employ multiple cell-autonomous defense mechanisms to impede pathogenesis of microbial intruders. Previously we identified an exocytosis defense mechanism in Arabidopsis against pathogenic powdery mildew fungi. This pre-invasive defense mechanism depends on the formation of ternary protein complexes consisting of the plasma membrane-localized PEN1 syntaxin, the adaptor protein SNAP33, and closely sequence-related vesicle-resident VAMP721 or VAMP722 proteins. The Arabidopsis thaliana resistance to powdery mildew 8.2 protein (RPW8.2) confers disease resistance against powdery mildews upon fungal entry into host cells and is specifically targeted to the extrahaustorial membrane (EHM), which envelops the haustorial complex of the fungus. However, the secretory machinery involved in trafficking RPW8.2 to the EHM is unknown. Here we report that RPW8.2 is transiently located on VAMP721/722 vesicles, and later incorporated into the EHM of mature haustoria. RPW8.2 resistance activity against the powdery mildew Golovinomyces orontii is greatly diminished in the absence of VAMP721 but only slightly in the absence of VAMP722. Consistent with this result, trafficking of RPW8.2 to the EHM is delayed in the absence of VAMP721. These findings implicate VAMP721/722 vesicles as key components of the secretory machinery for carrying RPW8.2 to the plant-fungal interface. Quantitative fluorescence recovery after photobleaching suggests that vesicle-mediated trafficking of RPW8.2-YFP to the EHM occurs transiently during early haustorial development and that RPW8.2-YFP lateral diffusion within the EHM exceeds vesicle-mediated RPW8.2-YFP replenishment in mature haustoria. Our findings imply the engagement of VAMP721/722 in a bifurcated trafficking pathway for pre-invasive defense at the cell periphery and post-invasive defense at the EHM.

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Rakesh Yashroy's curator insight, July 2, 11:08 AM

Membrane vesicle trafficking - the 2013 Nobel winning eukaryote cell phenomenon -  is now turning out to be universal, including bacteria @ http://en.wikipedia.org/wiki/Membrane_vesicle_trafficking

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Tweet from @LatAmSci on coffee rust (2014)

Tweet from @LatAmSci on coffee rust (2014) | Plants and Microbes | Scoop.it

Coffee Crop Disease, Spurred by Climate Change, Threatens Latin America http://www.latinpost.com/articles/14814/20140614/coffee-crop-disease-spurred-climate-change-threatens-latin-americas-economic.htm 

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Australia: New leaf rust threat to popular wheat varieties (2014)

Australia: New leaf rust threat to popular wheat varieties (2014) | Plants and Microbes | Scoop.it

WA wheatgrowers have been advised to monitor crops throughout the season for signs of leaf rust following testing which confirmed an increased risk of rust in popular wheat varieties. Department of Agriculture and Food plant pathologist Geoff Thomas said that in 2013, wheat leaf rust with increased virulence for several popular varieties was discovered in WA. Testing through the Australian Cereal Rust Control Program at Sydney University confirmed the presence of the leaf rust pathotype named 76-1, 3, 5, 7, 9, 10, 12 +Lr 37. "This represents the first occurrence in WA of virulence for varieties which contain Lr13 resistance," Mr Thomas said. "As a result, several varieties, including Mace, are expected to have an altered response in the presence of this pathotype. "In order to gauge the rust response of wheat varieties popular in WA, the Department recently completed glasshouse trials to test the seedling and adult reactions of varieties to this new pathotype. "Our pathology tests confirmed that varieties Mace, Wyalkatchem and Corack, which all carry Lr13, are susceptible (S) as seedlings and moderately susceptible to susceptible (MS-S) as adult plants. "This result signifies a significant reduction in resistance from the moderately-resistant (MR) response of these varieties to the former dominant rust pathotype in WA.


Via CIMMYT, Int.
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Curr Opin Plant Biol: Cross-interference of plant development and plant–microbe interactions (2014)

Curr Opin Plant Biol: Cross-interference of plant development and plant–microbe interactions (2014) | Plants and Microbes | Scoop.it

Plant roots are host to a multitude of filamentous microorganisms. Among these, arbuscular mycorrhizal fungi provide benefits to plants, while pathogens trigger diseases resulting in significant crop yield losses. It is therefore imperative to study processes which allow plants to discriminate detrimental and beneficial interactions in order to protect crops from diseases while retaining the ability for sustainable bio-fertilisation strategies. Accumulating evidence suggests that some symbiosis processes also affect plant–pathogen interactions. A large part of this overlap likely constitutes plant developmental processes. Moreover, microbes utilise effector proteins to interfere with plant development. Here we list relevant recent findings on how plant–microbe interactions intersect with plant development and highlight future research leads.

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Steve Marek's curator insight, June 16, 2:56 PM

Nice review

Rakesh Yashroy's curator insight, July 2, 10:54 AM

Microbe-macrobe or host-pathogen interface determines the cell-cell interactions largely @ http://en.wikipedia.org/wiki/Host-pathogen_interface

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PLOS One: Mutational Analysis of the Ve1 Immune Receptor That Mediates Verticillium Resistance in Tomato (2014)

PLOS One: Mutational Analysis of the Ve1 Immune Receptor That Mediates Verticillium Resistance in Tomato (2014) | Plants and Microbes | Scoop.it

Pathogenic Verticillium species are economically important plant pathogens that cause vascular wilt diseases in hundreds of plant species. The Ve1 gene of tomato confers resistance against race 1 strains of Verticillium dahliae and V. albo-atrumVe1 encodes an extracellular leucine-rich repeat (eLRR) receptor-like protein (RLP) that serves as a cell surface receptor for recognition of the recently identified secreted Verticillium effector Ave1. To investigate recognition of Ave1 by Ve1, alanine scanning was performed on the solvent exposed β-strand/β-turn residues across the eLRR domain of Ve1. In addition, alanine scanning was also employed to functionally characterize motifs that putatively mediate protein-protein interactions and endocytosis in the transmembrane domain and the cytoplasmic tail of the Ve1 protein. Functionality of the mutant proteins was assessed by screening for the occurrence of a hypersensitive response upon co-expression with Ave1 upon Agrobacterium tumefaciens-mediated transient expression (agroinfiltration). In order to confirm the agroinfiltration results, constructs encoding Ve1 mutants were transformed into Arabidopsis and the transgenes were challenged with race 1 Verticillium. Our analyses identified several regions of the Ve1 protein that are required for functionality.

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PLOS Biology : The Promise of Plant Translational Research (2014)

PLOS Biology : The Promise of Plant Translational Research (2014) | Plants and Microbes | Scoop.it

As the world's human population continues to expand, and as water resources come under increasing pressure and pathogens that cause devastating crop losses continue to spread in the face of increased global commerce and climate change, there is a pressing need for plant research to contribute solutions to improving food security in a sustainable and safe way.


Plant translational research - the development of basic plant research discoveries into technologies or approaches that improve agriculture - has a vital role to play in meeting these challenges, and given the importance of research in this field, PLOS believes that such work should be published in open access journals, ensuring that it reaches the widest possible audience without any barriers to access.


The technical advances highlighted in this PLOS Collection exemplify how basic research discoveries are being translated into methods to develop and improve, both agriculturally and environmentally, important crop traits.


At PLOS, we are committed to supporting breakthroughs in both basic and translational plant science. We encourage plant researchers to submit their high quality plant research and, in particular, plant research that has clear translational possibilities.


The Collection was produced with the support of The Bill & Melinda Gates Foundation.


The Collection will be updated periodically with new Plant Translational Research.


www.ploscollections.org/planttranslationalresearch

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News: The Betrayal of the Aphids (2014)

News: The Betrayal of the Aphids (2014) | Plants and Microbes | Scoop.it

Aphids are devastating insect pests and cause great losses to agriculture worldwide. These sap-feeding plant pests harbor in their body cavity bacteria, which are essential for the aphids’ fecundity and survival. Buchnera, the bacterium, benefits also because it cannot grow outside the aphid. This mutually beneficial relationship is sabotaged, however, by the bacterium which proceeds to betray the aphid, a research team led by scientists at the University of California, Riverside has found.


“Although this betrayal is unintentional, it nevertheless alerts the plant about the aphid’s presence and the aphids are unable to reproduce in large numbers,” said Isgouhi Kaloshian, a professor of nematology, who led the research project. “A protein from the bacterium, found in the aphid saliva and likely delivered inside the plant host by the aphid, triggers plant immune responses against the aphid. It seems that the plant immune system targets the bacterium and exploits the strict mutual dependency between the plant and aphid to recognize the aphid as the intruder.”


Study results appear online this week in the Proceedings of the National Academy of Sciences http://www.pnas.org/content/early/2014/06/03/1407687111.abstract

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Curr Opin Plant Biol: Inside plant: biotrophic strategies to modulate host immunity and metabolism (2014)

Curr Opin Plant Biol: Inside plant: biotrophic strategies to modulate host immunity and metabolism (2014) | Plants and Microbes | Scoop.it
Filamentous plant pathogens that establish biotrophic interactions need to avoid plant immune responses. Recent findings from different pathosystems suggest that sufficient suppression of host immunity is based on the modulation of a rather limited number of host targets. Microbial strategies to target host physiology dependent on the duration of biotrophy, the style of host tissue colonization and the degree of interference with plant development. In this article, we present current concepts in biotrophic virulence strategies and discuss mechanisms of pathogen adaptation and effector specialization.
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Storify: #MPMI2014 Day 4 of XVI IC-MPMI, Rhodes, Greece, 6-10 July

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Storify Tweet Archive of #MPMI2014 Days 1 and 2 of XVI IC-MPMI, Rhodes, Greece, 6-10 July

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Plant Physiology Cover — July 2014

Plant Physiology Cover  — July 2014 | Plants and Microbes | Scoop.it

Filamentous plant pathogens such as the late blight pathogenPhytophthora infestans form digit-like infection structures called haustoria inside plant cells. Haustoria enable the pathogen to feed on its host, and secrete effector proteins that modulate the physiology of the host cell to facilitate infection. Haustoria are enveloped by a specialized plant-derived membrane (the extrahaustorial membrane) the biogenesis of which is poorly understood. In this issue, Bozkurt et al. http://www.plantphysiol.org/content/165/3/1005 used the plant membrane microdomain protein REMORIN1.3, known to accumulate around P. infestans haustoria, to reveal discrete extrahaustorial domains labeled by REMORIN1.3 and P. infestans effector AVRblb2. SYNAPTOTAGMIN1, another previously identified perihaustorial protein, localized to subdomains which are mainly not labeled by REMORIN1.3 and AVRblb2. Functional characterization of REMORIN1.3 revealed that it is a susceptibility factor that promotes infection by P. infestans. This activity, and REMORIN1.3 recruitment to the EHM, require REM1.3 membrane-binding domain. These results implicate REMORIN1.3 membrane microdomains in plant susceptibility to an oomycete pathogen. The cover shows Nicotiana benthamiana epidermal cells expressing fluorescently labeled REMORIN1.3 (blue) infected by P. infestans expressing the red fluorescent protein (red). Cover image credits: Sylvain Raffaele.

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Plant J: Suppression among alleles encoding NB-LRR resistance proteins interferes with resistance in F1 hybrid and allele-pyramided wheat plants (2014)

Plant J: Suppression among alleles encoding NB-LRR resistance proteins interferes with resistance in F1 hybrid and allele-pyramided wheat plants (2014) | Plants and Microbes | Scoop.it

Developing high yielding varieties with broad-spectrum and durable disease resistance is the ultimate goal of crop breeding. In plants, immune receptors of the NB-LRR class mediate race-specific resistance against pathogen attack. This type of resistance is often rapidly overcome by newly adapted pathogen races when employed in agriculture. The stacking of different resistance genes or alleles in F1 hybrids or in pyramided lines is a promising strategy to achieve more durable resistance. Here, we identify a molecular mechanism which can negatively interfere with the allele-pyramiding approach. We show that pairwise combinations of different alleles of the powdery-mildew-resistance gene Pm3 in F1 hybrids and stacked transgenic wheat lines can result in suppression of Pm3-based resistance. This effect is independent of the genetic background and solely dependent on the Pm3 alleles. Suppression occurs at the post-translational level as neither RNA nor protein levels of the suppressed alleles are affected. Using a transient-expression system in Nicotiana benthamiana, the LRR domain was identified as the suppression-conferring domain. The results of this study suggest that the expression of closely related NB-LRR resistance genes or alleles in the same genotype can lead to dominant-negative interactions. These findings provide a molecular explanation for the frequently observed ineffectiveness of resistance genes introduced from the secondary gene pool into polyploid crop species and mark an important step to overcome this limitation.

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Plant & Cell Physiol: Ectopic Expression of RESISTANCE TO POWDERY MILDEW8.1 Confers Resistance to Fungal and Oomycete Pathogens in Arabidopsis (2014)

Plant & Cell Physiol: Ectopic Expression of RESISTANCE TO POWDERY MILDEW8.1 Confers Resistance to Fungal and Oomycete Pathogens in Arabidopsis (2014) | Plants and Microbes | Scoop.it

Broad-spectrum disease resistance is a highly valuable trait in plant breeding and attracts special attention in research. The Arabidopsis gene locus RESISTANCE TO POWDERY MILDEW 8 (RPW8) contains two adjacent homologous genes, RPW8.1 and RPW8.2, and confers broad-spectrum resistance to powdery mildew. Remarkably, the RPW8.2 protein is specifically localized to the extrahaustorial membrane (EHM) encasing the feeding structure of powdery mildew whereby RPW8.2 activates haustorium-targeted defenses. Here, we show that ectopic expression of the yellow fluorescent protein (YFP)-tagged RPW8.1 from the native promoter leads to unique cell death lesions and enhances resistance to virulent fungal and oomycete pathogens that cause powdery mildew and downy mildew diseases, respectively. In powdery mildew infected plants, RPW8.1-YFP accumulates at higher levels in the mesophyll cells underneath the infected epidermal cells where RPW8.2-YFP is mainly expressed. This cell-type-preferential protein accumulation pattern largely correlates with that of H2O2 accumulation, suggesting that RPW8.1 may spatially collaborate with RPW8.2 in activation of resistance to powdery mildew. Interestingly, when ectopically expressed from theRPW8.2 promoter, RPW8.1-YFP is also targeted to the EHM of powdery mildew and the transgenic plants display resistance to both powdery mildew and downy mildew. Using YFP as a reporter, we further reveal that the RPW8.1 promoter is constitutively active but induced to higher levels in cells at the infection site, whereas the RPW8.2 promoter is activated specifically in cells at the infection site. Taken together, our results suggest that RPW8.1 (and its promoter) is functionally distinct fromRPW8.2 and may have a higher potential in engineering broad-spectrum resistance in plants.

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Schornack Lab: a bursting spore of the arbuscular mycorrhiza fungus Rhizophagus irregularis - releasing oil droplets (2014)

Schornack Lab: a bursting spore of the arbuscular mycorrhiza fungus Rhizophagus irregularis - releasing oil droplets (2014) | Plants and Microbes | Scoop.it

Via Jean-Michel Ané
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Hemipteran-plant Interactions Symposium, Riverside, California, June 22-15, 2014

Hemipteran-plant Interactions Symposium, Riverside, California, June 22-15, 2014 | Plants and Microbes | Scoop.it

The 2014 Hemipteran-Plant Interactions Symposium (HPIS) is an interdisciplinary symposium bringing together researchers who study phytophagous piercing/sucking insects, their complex interactions with their host plants, and transmission of plant pathogens. The Symposium is designed to facilitate an exchange of ideas and foster collaborations among entomologists with expertise on phytophagous hemipteran insects (Orders Hemiptera and Thysanoptera) and their endosymbionts, plant biologists and physiologists with expertise on plant defenses and responses to hemipteran feeding, and plant pathologists with expertise on transmission of plant pathogens by hemipterans. The symposium will feature a stellar line-up of plenary speakers from the disciplines of entomology, plant biology and plant pathology, and is soliciting oral and poster presentations from participants. There also are two satellite workshops affiliated with the symposium: a pre-symposium Electrical Penetration Graph (EPG) Workshop and post-Symposium OMICs workshop.

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BMC Plant Biology: Identification of a dominant gene in Medicago truncatula that restricts nodulation by Sinorhizobium meliloti strain Rm41 (2014)

BMC Plant Biology: Identification of a dominant gene in Medicago truncatula that restricts nodulation by Sinorhizobium meliloti strain Rm41 (2014) | Plants and Microbes | Scoop.it

Background - Leguminous plants are able to form a root nodule symbiosis with nitrogen-fixing soil bacteria called rhizobia. This symbiotic association shows a high level of specificity. Beyond the specificity for the legume family, individual legume species/genotypes can only interact with certain restricted group of bacterial species or strains. Specificity in this system is regulated by complex signal exchange between the two symbiotic partners and thus multiple genetic mechanisms could be involved in the recognition process. Knowledge of the molecular mechanisms controlling symbiotic specificity could enable genetic improvement of legume nitrogen fixation, and may also reveal the possible mechanisms that restrict root nodule symbiosis in non-legumes.


Results - We screened a core collection of Medicago truncatula genotypes with several strains of Sinorhizobium meliloti and identified a naturally occurring dominant gene that restricts nodulation by S. meliloti Rm41. We named this gene as Mt-NS1 (for M. truncatula nodulation specificity 1). We have mapped the Mt-NS1 locus within a small genomic region on M. truncatula chromosome 8. The data reported here will facilitate positional cloning of the Mt-NS1 gene.


Conclusions - Evolution of symbiosis specificity involves both rhizobial and host genes. From the bacterial side, specificity determinants include Nod factors, surface polysaccharides, and secreted proteins. However, we know relatively less from the host side. We recently demonstrated that a component of this specificity in soybeans is defined by plant NBS-LRR resistance (R) genes that recognize effector proteins delivered by the type III secretion system (T3SS) of the rhizobial symbionts. However, the lack of a T3SS in many sequenced S. meliloti strains raises the question of how the specificity is regulated in the Medicago-Sinorhizobium system beyond Nod-factor perception. Thus, cloning and characterization of Mt-NS1 will add a new dimension to our knowledge about the genetic control of nodulation specificity in the legume-rhizobial symbiosis.

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Buzzfeed: 11 Plant Diseases That Could Make Your Favorite Foods Disappear (2014)

Buzzfeed: 11 Plant Diseases That Could Make Your Favorite Foods Disappear (2014) | Plants and Microbes | Scoop.it

You know people and animals get sick, but plants also get sick. Plant diseases threaten some of the world’s favorite food sources. Luckily, plant pathologists (plant doctors) stand between plant diseases and the world’s food supply.

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Anniversary Publications to be Celebrated at the XVI IC-MPMI, Rhodes, Greece, July 2014

Anniversary Publications to be Celebrated at the XVI IC-MPMI, Rhodes, Greece, July 2014 | Plants and Microbes | Scoop.it

Cloning of the First Plant Immune Receptor Genes


Bent, A. F., Kunkel, B. N., Dahlbeck, D., Brown, K. L., Schmidt, R., Giraudat, J., Leung, J., and Staskawicz, B. J. 1994. RPS2 of Arabidopsis thaliana: A leucine-rich repeat class of plant disease resistance genes. Science 265:1856-1860.


Grant, M. R., Godiard, L., Straube, E., Ashfield, T., Lewald, J., Sattler, A., Innes, R. W., and Dangl, J. L. 1995. Structure of the Arabidopsis RPM1 gene which enables dual-specificity disease resistance. Science 269:843-846.


Jones, D. A., Thomas, C. M., Hammond-Kosack, K. E., Balint- Kurti, P. J., and Jones, J. D. 1994. Isolation of the tomato Cf-9 gene for resistance to Cladosporium fulvum by transposon tagging. Science 266:789-793.


Lawrence, G. J., Finnegan, E. J., Ayliffe, M. A., and Ellis, J. G. 1995. The L6 gene for flax rust resistance is related to the Arabidopsis bacterial resistance gene RPS2 and the tobacco viral resistance gene N. Plant Cell 7:1195-1206.


Martin, G. B., Brommonschenkel, S. H., Chunwongse, J., Frary, A., Ganal, M. W., Spivey, R., Wu, T., Earle, E. D., and Tanksley, S. D. 1993. Map-based cloning of a protein kinase gene conferring disease resistance in tomato. Science 262:1432-1436.


Mindrinos, M., Katagiri, F., Yu, G. L., and Ausubel, F. M. 1994. The A. thaliana disease resistance gene RPS2 encodes a protein containing a nucleotide-binding site and leucine-rich repeats. Cell 78:1089-1099.


Song, W. Y., Wang, G. L., Chen, L. L., Kim, H. S., Pi, L. Y., Holsten, T., Gardner, J., Wang, B., Zhai, W. X., Zhu, L. H., Fauquet, C., and Ronald, P. 1995. A receptor kinase-like protein encoded by the rice disease resistance gene Xa21. Science 270:1804-1806.


Whitham, S., Dinesh-Kumar, S. P., Choi, D., Hehl, R., Corr, C., and Baker, B. 1994. The product of the tobacco mosaic virus resistance gene N: Similarity to toll and the interleukin-1 receptor. Cell 78:1101- 1115.


Cloning of the First Plant Pathogen Avirulence Effector Gene


Staskawicz, B. J., Dahlbeck, D., and Keen, N. T. 1984. Cloned avirulence gene of Pseudomonas syringae pv. glycinea determines racespecific incompatibility on Glycine max (L.) Merr. Proc. Natl. Acad. Sci. USA 81:6024-6028.


IS-MPMI Reporter issue 2, 2014 http://www.ismpminet.org/Newsletter/2014_Iss2.asp

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New Phytologist: Multiple recognition of RXLR effectors is associated with nonhost resistance of pepper against Phytophthora infestans (2014)

New Phytologist: Multiple recognition of RXLR effectors is associated with nonhost resistance of pepper against Phytophthora infestans (2014) | Plants and Microbes | Scoop.it
  • Nonhost resistance (NHR) is a plant immune response to resist most pathogens. The molecular basis of NHR is poorly understood, but recognition of pathogen effectors by immune receptors, a response known as effector-triggered immunity, has been proposed as a component of NHR.
  • We performed transient expression of 54 Phytophthora infestansRXLR effectors in pepper (Capsicum annuum) accessions. We used optimized heterologous expression methods and analyzed the inheritance of effector-induced cell death in an F2 population derived from a cross between two pepper accessions.
  • Pepper showed a localized cell death response upon inoculation with P. infestans, suggesting that recognition of effectors may contribute to NHR in this system. Pepper accessions recognized as many as 36 effectors. Among the effectors, PexRD8 and Avrblb2 induced cell death in a broad range of pepper accessions. Segregation of effector-induced cell death in an F2 population derived from a cross between two pepper accessions fit 15 : 1, 9 : 7 or 3 : 1 ratios, depending on the effector.
  • Our genetic data suggest that a single or two independent/complementary dominant genes are involved in the recognition of RXLR effectors. Multiple loci recognizing a series of effectors may underpin NHR of pepper to P. infestans and confer resistance durability.
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Curr Opin Plant Biol: Filamentous pathogen effector functions: of pathogens, hosts and microbiomes (2014)

Curr Opin Plant Biol: Filamentous pathogen effector functions: of pathogens, hosts and microbiomes (2014) | Plants and Microbes | Scoop.it

Microorganisms play essential roles in almost every environment on earth. For instance, microbes decompose organic material, or establish symbiotic relationships that range from pathogenic to mutualistic. Symbiotic relationships have been particularly well studied for microbial plant pathogens and have emphasized the role of effectors; secreted molecules that support host colonization. Most effectors characterized thus far play roles in deregulation of host immunity. Arguably, however, pathogens not only deal with immune responses during host colonization, but also encounter other microbes including competitors, (myco)parasites and even potential co-operators. Thus, part of the effector catalog may target microbiome co-inhabitants rather than host physiology.

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Rakesh Yashroy's curator insight, July 2, 11:16 AM

Host-pathogen interface is the 'kurukshetra' or battlefield of life @ http://en.wikipedia.org/wiki/Host-pathogen_interface