Plant-Microbe Int...
Follow
Find
14.4K views | +14 today
 
Rescooped by Guogen Yang from Plant-microbe interaction
onto Plant-Microbe Interaction
Scoop.it!

A really useful pathogen, Agrobacterium tumefaciens. New Teaching Tool.

A really useful pathogen, Agrobacterium tumefaciens. New Teaching Tool. | Plant-Microbe Interaction | Scoop.it

The soil bacterium Agrobacterium tumefaciens has a special place in plant biology. Through a rare inter-kingdom DNA transfer, the bacteria move some of their genes into their host's genome, thereby inducing the host cells to proliferate and produce opines, which are nutrients sources for the pathogen. Agrobacterium's ability to transfer DNA makes can be adapted to introduce other genes, such as those encoding useful traits, into plant genomes. The development of Agrobacterium as a tool to transform plants is a landmark event in modern plant biology. This new "Teaching Tool in Plant Biology" provides an introduction to Agrobacterium tumefaciens and related species, focusing on their modes of pathogenicity, their usefulness as tools for plant transformation, and their use as a model for the study of plant-pathogen interactions.

Find it here: http://www.plantcell.org/site/teachingtools/TTPB23.xhtml (subscription to Plant Cell or ASPB membership required).


Via Mary Williams, Nicolas Denancé, Suayib Üstün
more...
Lidia Pérez de Obanos's curator insight, November 27, 2013 9:15 AM

Agrobacterium tumefaciens es un vector muy útil para muchos tipos de genes que se quieren introducir en distintas plantas. Gracias a ella hemos podido realizar múltiples experimentos y es muy fácil de realizar.

From around the web

Plant-Microbe Interaction
plant-microbe interaction
Curated by Guogen Yang
Your new post is loading...
Your new post is loading...
Rescooped by Guogen Yang from Plant Immunity And Microbial Effectors
Scoop.it!

Anthocyanin leaf markings are regulated by a family of R2R3-MYB genes in the genus Trifolium

Anthocyanin leaf markings are regulated by a family of R2R3-MYB genes in the genus Trifolium | Plant-Microbe Interaction | Scoop.it
Summary
Anthocyanin pigments accumulate to form spatially restricted patterns in plants, particularly in flowers, but also occur in vegetative tissues.

Via IPM Lab
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interactions (on the plant's side)
Scoop.it!

GLYCINE-RICH RNA-BINDING PROTEIN1 interacts with RECEPTOR-LIKE CYTOPLASMIC PROTEIN KINASE1 and suppresses cell death and defense responses in pepper (Capsicum annuum)

GLYCINE-RICH RNA-BINDING PROTEIN1 interacts with RECEPTOR-LIKE CYTOPLASMIC PROTEIN KINASE1 and suppresses cell death and defense responses in pepper (Capsicum annuum) | Plant-Microbe Interaction | Scoop.it

Plants use a variety of innate immune regulators to trigger cell death and defense responses against pathogen attack.We identified pepper (Capsicum annuum) GLYCINE-RICH RNA-BINDING PROTEIN1 (CaGRP1) as a RECEPTOR-LIKE CYTOPLASMIC PROTEIN KINASE1 (CaPIK1)-interacting partner, based on bimolecular fluorescence complementation and coimmunoprecipitation analyses as well as gene silencing and transient expression analysis.CaGRP1 contains an N-terminal RNA recognition motif and a glycine-rich region at the C-terminus. The CaGRP1 protein had DNA- and RNA-binding activity in vitro. CaGRP1 interacted with CaPIK1 in planta. CaGRP1 and CaGRP1–CaPIK1 complexes were localized to the nucleus in plant cells. CaPIK1 phosphorylated CaGRP1 in vitro and in planta. Transient coexpression of CaGRP1 with CaPIK1 suppressed the CaPIK1-triggered cell death response, accompanied by a reduced CaPIK1-triggered reactive oxygen species (ROS) burst. The RNA recognition motif region of CaGRP1 was responsible for the nuclear localization of CaGRP1 as well as the suppression of the CaPIK1-triggered cell death response. CaGRP1 silencing in pepper conferred enhanced resistance to Xanthomonas campestris pv vesicatoria (Xcv) infection; however, CaPIK1-silenced plants were more susceptible to Xcv.CaGRP1 interacts with CaPIK1 and negatively regulates CaPIK1-triggered cell death and defense responses by suppressing ROS accumulation.


Via Christophe Jacquet
more...
No comment yet.
Rescooped by Guogen Yang from Rice Blast
Scoop.it!

Systematic characterization of the bZIP transcription factor gene family in the rice blast fungus, Magnaporthe oryzae

Systematic characterization of the bZIP transcription factor gene family in the rice blast fungus, Magnaporthe oryzae | Plant-Microbe Interaction | Scoop.it

In this study the 22 Magnaporthe oryzae genes encoding bZIP transcription factors were systematically characterized. Phylogenetic analysis of fungal bZIP TFs revealed that 7 MobZIPs are Magnaporthe-specific while others belongs to 15 clades of orthologous Ascomycota genes. Expression patterns of MobZIPs under various conditions showed that they are highly stress-responsive. We generated deletion mutants for 13 MobZIPs: 9 with orthologs in other fungal species and 4 Magnaporthe-specific ones. Seven of them exhibited defects in mycelial growth, development, and/or pathogenicity. Consistent with the conserved functions of the orthologs, MobZIP22 and MobZIP13 played a role in sulfur metabolism and iron homeostasis, respectively. Along with MobZIP22 and MobZIP13, one Magnaporthe-specific gene, MobZIP11 is essential for pathogenicity in a ROS-dependent manner. 


Via Elsa Ballini
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interactions (on the plant's side)
Scoop.it!

The effective papilla hypothesis -

The effective papilla hypothesis - | Plant-Microbe Interaction | Scoop.it
Keywords:

arabinoxylan;
callose;
cell wall apposition;
cellulose;
papilla;
penetration resistance;
powdery mildew

In phytopathology, little is understood about what stops a parasitic fungus from penetrating a host cell wall. Plants often form cell wall appositions, called papillae, in response to fungal attempts to penetrate their cell wall, and the molecular composition of these papillae differs from that of primary and secondary cell walls. However, we do not know whether altered cell wall composition is critical for restricting penetration. In this issue of New Phytologist, Chowdhury et al. (pp. 650–660) used the model interaction of barley (Hordeum vulgare) with the barley-adapted grass powdery mildew fungus (Blumeria graminis f. sp. hordei) to study this phenomenon. The work by Chowdhury et al. significantly adds to our understanding of what distinguishes a papilla, in which a fungal penetration attempt failed, from a penetrated papilla. Using an immunohistochemical approach, Chowdhury et al. identified that callose, arabinoxylans, and cellulose are significantly enriched in nonpenetrated papillae (NPP) over penetrated papillae (PP) and showed that papilla composition is determined in a cell-autonomous fashion. This opens up new possibilities for experimental designs that may help to answer the question of whether papillary cell wall polymers contribute significantly to penetration resistance.

Via Christophe Jacquet
more...
No comment yet.
Rescooped by Guogen Yang from Rice Blast
Scoop.it!

Threonine deaminase MoIlv1 is important for conidiogenesis and pathogenesis in the rice blast fungus Magnaporthe oryzae

Threonine deaminase MoIlv1 is important for conidiogenesis and pathogenesis in the rice blast fungus Magnaporthe oryzae | Plant-Microbe Interaction | Scoop.it

MoIlv1 is important for conidial morphology, asexual development, penetration and pathogenicity inM. oryzae.

The PALP, DEH1 and DEH2 domain are/is required for the full function of MoIlv1 during growth, development and pathogenicity


Via Elsa Ballini
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interaction
Scoop.it!

Nucleotide-binding oligomerization domain-like receptor cooperativity in effector-triggered immunity

Nucleotide-binding oligomerization domain-like receptor cooperativity in effector-triggered immunity | Plant-Microbe Interaction | Scoop.it

Intracellular nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) are basic elements of innate immunity in plants and animals. Whereas animal NLRs react to conserved microbe- or damage-associated molecular patterns, plant NLRs intercept the actions of diverse pathogen virulence factors (effectors). In this review, we discuss recent genetic and molecular evidence for functional NLR pairs, and discuss the significance of NLR self-association and heteromeric NLR assemblies in the triggering of downstream signaling pathways. We highlight the versatility and impact of cooperating NLR pairs that combine pathogen sensing with the initiation of defense signaling in both plant and animal immunity. We propose that different NLR receptor molecular configurations provide opportunities for fine-tuning resistance pathways and enhancing the host's pathogen recognition spectrum to keep pace with rapidly evolving microbial populations.

  


Via Suayib Üstün
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interaction
Scoop.it!

Expression Profiling during Arabidopsis/Downy Mildew Interaction Reveals a Highly-Expressed Effector That Attenuates Responses to Salicylic Acid

Expression Profiling during Arabidopsis/Downy Mildew Interaction Reveals a Highly-Expressed Effector That Attenuates Responses to Salicylic Acid | Plant-Microbe Interaction | Scoop.it
Plants have evolved strong innate immunity mechanisms, but successful pathogens evade or suppress plant immunity via effectors delivered into the plant cell. Hyaloperonospora arabidopsidis (Hpa) causes downy mildew on Arabidopsis thaliana, and a genome sequence is available for isolate Emoy2. Here, we exploit the availability of genome sequences for Hpa and Arabidopsis to measure gene-expression changes in both Hpa and Arabidopsis simultaneously during infection. Using a high-throughput cDNA tag sequencing method, we reveal expression patterns of Hpa predicted effectors and Arabidopsis genes in compatible and incompatible interactions, and promoter elements associated with Hpa genes expressed during infection. By resequencing Hpa isolate Waco9, we found it evades Arabidopsis resistance gene RPP1 through deletion of the cognate recognized effector ATR1. Arabidopsis salicylic acid (SA)-responsive genes including PR1 were activated not only at early time points in the incompatible interaction but also at late time points in the compatible interaction. By histochemical analysis, we found that Hpa suppresses SA-inducible PR1 expression, specifically in the haustoriated cells into which host-translocated effectors are delivered, but not in non-haustoriated adjacent cells. Finally, we found a highly-expressed Hpa effector candidate that suppresses responsiveness to SA. As this approach can be easily applied to host-pathogen interactions for which both host and pathogen genome sequences are available, this work opens the door towards transcriptome studies in infection biology that should help unravel pathogen infection strategies and the mechanisms by which host defense responses are overcome.

Via Suayib Üstün
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interactions (on the plant's side)
Scoop.it!

The brassinosteroid chemical toolbox

The brassinosteroid chemical toolbox | Plant-Microbe Interaction | Scoop.it
Highlights



Brassinosteroid research benefited from several chemical biology approaches.


Small molecules target biosynthesis as well as signaling.


Analogs of brassinolide allowed binding studies and visualization.


Small molecules present large opportunities for future brassinosteroid research.

Chemical biology approaches have been instrumental in understanding the mode of action of brassinosteroids, a group of plant steroid hormones essential for plant development and growth. The small molecules used for such approaches include inhibitors of biosynthetic enzymes and signaling components. Additionally, recent structural data on the brassinosteroid receptor complex together with its ligand brassinolide, the most active brassinosteroid, and knowledge on its different analogs have given us a better view on the recognition of the hormone and signaling initiation. Moreover, a fluorescently labeled brassinosteroid enabled the visualization of the receptor–ligand pair in the cell. Given the insights obtained, small molecules will continue to provide new opportunities for probing brassinosteroid biosynthesis and for unraveling the dynamic and highly interconnected signaling.

Via Christophe Jacquet
more...
Mary Williams's curator insight, October 15, 7:54 AM

Oh - super review from the Dec 2014 Curr Opin Plant Biol!

I'm reading this on the plane tonight!

Rescooped by Guogen Yang from Plant-microbe interactions (on the plant's side)
Scoop.it!

Large-scale transcriptome comparison reveals distinct gene activations in wheat responding to stripe rust and powdery mildew

Large-scale transcriptome comparison reveals distinct gene activations in wheat responding to stripe rust and powdery mildew | Plant-Microbe Interaction | Scoop.it
Background

Stripe rust (Puccinia striiformis f. sp. tritici; Pst) and powdery mildew (Blumeria graminis f. sp. tritici; Bgt) are important diseases of wheat (Triticum aestivum) worldwide. Similar mechanisms and gene transcripts are assumed to be involved in the host defense response because both pathogens are biotrophic fungi. The main objective of our study was to identify co-regulated mRNAs that show a change in expression pattern after inoculation with Pst or Bgt, and to identify mRNAs specific to the fungal stress response.

Results

The transcriptome of the hexaploid wheat line N9134 inoculated with the Chinese Pst race CYR 31 was compared with that of the same line inoculated with Bgt race E09 at 1, 2, and 3 days post-inoculation. Infection by Pst and Bgt affected transcription of 23.8% of all T. aestivum genes. Infection by Bgt triggered a more robust alteration in gene expression in N9134 compared with the response to Pst infection. An array of overlapping gene clusters with distinctive expression patterns provided insight into the regulatory differences in the responses to Bgt and Pst infection. The differentially expressed genes were grouped into seven enriched Kyoto Encyclopedia of Genes and Genomes pathways in Bgt-infected leaves and four pathways in Pst-infected leaves, while only two pathways overlapped. In the plant-pathogen interaction pathway, N9134 activated a higher number of genes and pathways in response to Bgt infection than in response to Pst invasion. Genomic analysis revealed that the wheat genome shared some microbial genetic fragments, which were specifically induced in response to Bgt and Pst infection.

Conclusions

Taken together, our findings indicate that the responses of wheat N9134 to infection by Bgt and Pst shows differences in the pathways and genes activated. The mass sequence data for wheat-fungus interaction generated in this study provides a powerful platform for future functional and molecular research on wheat-fungus interactions.

 

 


Via Christophe Jacquet
more...
No comment yet.
Scooped by Guogen Yang
Scoop.it!

GbWRKY1 mediates plant defense-to-development transition during infection of cotton by Verticillium dahliae by activating JAZ1 expression

Plants have evolved an elaborate signaling network to ensure an appropriate level of immune response to meet the differing demands of developmental processes. Previous research has demonstrated that DELLA proteins physically interact with JAZ1 and dynamically regulate the interaction of the gibberellic acid (GA) and jasmonic acid (JA) signaling pathways. However, whether and how the JAZ1-DELLA regulatory node is regulated at the transcriptional level in plants under normal growth conditions or during pathogen infection is not known. Here, we demonstrate multiple functions of Gossypium barbadense GbWRKY1 in the plant defense response and during development. Although GbWRKY1 expression is induced rapidly by MeJA and infection by Verticillium dahliae, our results show that GbWRKY1 is a negative regulator of the JA-mediated defense response and plant resistance to the pathogens Botrytis cinerea and V. dahliae. Under normal growth conditions, GbWRKY1-overexpressing lines displayed GA-associated phenotypes, including organ elongation and early flowering, coupled with the downregulation of the putative targets of DELLA. We show that the GA-related phenotypes of GbWRKY1-overexpressing plants depend on the constitutive expression of Gossypium hirsutum GhJAZ1. We also show that GhJAZ1 can be trans-activated by GbWRKY1 through TGAC core sequences, and the adjacent sequences of this binding site are essential for binding specificity and affinity to GbWRKY1 as revealed by dual-luciferase reporter assays and electrophoretic mobility shift assays. In summary, our data suggest that GbWRKY1 is a critical regulator mediating the plant defense-to-development transition during V. dahliae infection by activating JAZ1 expression.

more...
No comment yet.
Rescooped by Guogen Yang from MycorWeb Plant-Microbe Interactions
Scoop.it!

Origins of major archaeal clades correspond to gene acquisitions from bacteria : Nature

Origins of major archaeal clades correspond to gene acquisitions from bacteria : Nature | Plant-Microbe Interaction | Scoop.it
The mechanisms that underlie the origin of major prokaryotic groups are poorly understood. In principle, the origin of both species and higher taxa among prokaryotes should entail similar mechanisms[mdash]ecological interactions with the environment paired with natural genetic variation involving lineage-specific gene innovations and lineage-specific gene acquisitions. To investigate the origin of higher taxa in archaea, we have determined gene distributions and gene phylogenies for the 267,568 protein-coding genes of 134 sequenced archaeal genomes in the context of their homologues from 1,847 reference bacterial genomes. Archaeal-specific gene families define 13 traditionally recognized archaeal higher taxa in our sample. Here we report that the origins of these 13 groups unexpectedly correspond to 2,264 group-specific gene acquisitions from bacteria. Interdomain gene transfer is highly asymmetric, transfers from bacteria to archaea are more than fivefold more frequent than vice versa. Gene transfers identified at major evolutionary transitions among prokaryotes specifically implicate gene acquisitions for metabolic functions from bacteria as key innovations in the origin of higher archaeal taxa.

Via Francis Martin
more...
No comment yet.
Rescooped by Guogen Yang from MycorWeb Plant-Microbe Interactions
Scoop.it!

The genetics of monarch butterfly migration and warning colouration : Nature

The genetics of monarch butterfly migration and warning colouration : Nature | Plant-Microbe Interaction | Scoop.it
The monarch butterfly, Danaus plexippus, is famous for its spectacular annual migration across North America, recent worldwide dispersal, and orange warning colouration. Despite decades of study and broad public interest, we know little about the genetic basis of these hallmark traits. Here we uncover the history of the monarch’s evolutionary origin and global dispersal, characterize the genes and pathways associated with migratory behaviour, and identify the discrete genetic basis of warning colouration by sequencing 101 Danaus genomes from around the globe. The results rewrite our understanding of this classic system, showing that D. plexippus was ancestrally migratory and dispersed out of North America to occupy its broad distribution. We find the strongest signatures of selection associated with migration centre on flight muscle function, resulting in greater flight efficiency among migratory monarchs, and that variation in monarch warning colouration is controlled by a single myosin gene not previously implicated in insect pigmentation.

Via Francis Martin
more...
No comment yet.
Rescooped by Guogen Yang from MycorWeb Plant-Microbe Interactions
Scoop.it!

Genomics: Of monarchs and migration : Nature

Genomics: Of monarchs and migration : Nature | Plant-Microbe Interaction | Scoop.it

The genomes of 101 monarch butterflies from migratory and resident populations have been sequenced, revealing genes and molecular pathways that underlie insect migration and colouration.

Which evolved first, the temperate migratory populations or the resident tropical groups? For birds, the 'southern home' theory suggests that migratory populations arose from non-migratory tropical populations5. Surprisingly, Zhan and colleagues' analysis of migratory and non-migratory monarchs shows that these butterflies originated in North America, from a migratory ancestor. Tropical groups had reduced genetic diversity compared with their North American relatives, because they have gone through step-wise genetic bottlenecks during their colonization of the tropics, each of which reduced the diversity of their genomes.


Via Francis Martin
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interaction
Scoop.it!

Genome Biology | Abstract | Transcriptomic analysis reveals tomato genes whose expression is induced specifically during effector-triggered immunity and identifies the Epk1 protein kinase which is ...

Genome Biology | Abstract | Transcriptomic analysis reveals tomato genes whose expression is induced specifically during effector-triggered immunity and identifies the Epk1 protein kinase which is ... | Plant-Microbe Interaction | Scoop.it

Background: Plants have two related immune systems to defend themselves against pathogen attack. Initially, pattern-triggered immunity is activated upon recognition of microbe-associated molecular patterns by pattern recognition receptors. Pathogenic bacteria deliver effector proteins into the plant cell that interfere with this immune response and promote disease. However, some plants express resistance proteins that detect the presence of specific effectors leading to a robust defense response referred to as effector-triggered immunity. The interaction of tomato with Pseudomonas syringae pv. tomato is an established model system for understanding the molecular basis of these plant immune responses.ResultsWe apply high-throughput RNA sequencing to this pathosystem to identify genes whose expression changes specifically during pattern-triggered or effector-triggered immunity. We then develop reporter genes for each of these responses that will enable characterization of the host response to the large collection of P. s. pv. tomato strains that express different combinations of effectors. Virus-induced gene silencing of 30 of the effector-triggered immunity-specific genes identifies Epk1 which encodes a predicted protein kinase from a family previously unknown to be involved in immunity. Knocked-down expression of Epk1 compromises effector-triggered immunity triggered by three bacterial effectors but not by effectors from non-bacterial pathogens. Epistasis experiments indicate that Epk1 acts upstream of effector-triggered immunity-associated MAP kinase signaling.ConclusionsUsing RNA-seq technology we identify genes involved in specific immune responses. A functional genomics screen led to the discovery of Epk1, a novel predicted protein kinase required for plant defense activation upon recognition of three different bacterial effectors.


Via Suayib Üstün
more...
No comment yet.
Rescooped by Guogen Yang from MycorWeb Plant-Microbe Interactions
Scoop.it!

Overexpression of Laccaria bicolor aquaporin JQ585595 alters root water transport properties in ectomycorrhizal white spruce (Picea glauca) seedlings

Overexpression of Laccaria bicolor aquaporin JQ585595 alters root water transport properties in ectomycorrhizal white spruce (Picea glauca) seedlings | Plant-Microbe Interaction | Scoop.it

The contribution of hyphae to water transport in ectomycorrhizal (ECM) white spruce (Picea glauca) seedlings was examined by altering expression of a major water-transporting aquaporin in Laccaria bicolor.Picea glauca was inoculated with wild-type (WT), mock transgenic or L. bicolor aquaporin JQ585595-overexpressing (OE) strains and exposed to root temperatures ranging from 5 to 20°C to examine the root water transport properties, physiological responses and plasma membrane intrinsic protein (PIP) expression in colonized plants.Mycorrhization increased shoot water potential, transpiration, net photosynthetic rates, root hydraulic conductivity and root cortical cell hydraulic conductivity in seedlings. At 20°C, OE plants had higher root hydraulic conductivity compared with WT plants and the increases were accompanied by higher expression of P. glauca PIP GQ03401_M18.1 in roots. In contrast to WT L. bicolor, the effects of OE fungi on root and root cortical cell hydraulic conductivities were abolished at 10 and 5°C in the absence of major changes in the examined transcript levels of P. glauca root PIPs.The results provide evidence for the importance of fungal aquaporins in root water transport of mycorrhizal plants. They also demonstrate links between hyphal water transport, root aquaporin expression and root water transport in ECM plants.


Via Kevin Garcia, Jean-Michel Ané, Francis Martin
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interactions (on the plant's side)
Scoop.it!

Differential accumulation of callose, arabinoxylan and cellulose in nonpenetrated versus penetrated papillae on leaves of barley infected with Blumeria graminis f. sp. hordei

Differential accumulation of callose, arabinoxylan and cellulose in nonpenetrated versus penetrated papillae on leaves of barley infected with Blumeria graminis f. sp. hordei | Plant-Microbe Interaction | Scoop.it

In plants, cell walls are one of the first lines of defence for protecting cells from successful invasion by fungal pathogens and are a major factor in basal host resistance. For the plant cell to block penetration attempts, it must adapt its cell wall to withstand the physical and chemical forces applied by the fungus.Papillae that have been effective in preventing penetration by pathogens are traditionally believed to contain callose as the main polysaccharide component. Here, we have re-examined the composition of papillae of barley (Hordeum vulgare) attacked by the powdery mildew fungus Blumeria graminis f. sp. hordei (Bgh) using a range of antibodies and carbohydrate-binding modules that are targeted to cell wall polysaccharides.The data show that barley papillae induced during infection with Bgh contain, in addition to callose, significant concentrations of cellulose and arabinoxylan. Higher concentrations of callose, arabinoxylan and cellulose are found in effective papillae, compared with ineffective papillae. The papillae have a layered structure, with the inner core consisting of callose and arabinoxylan and the outer layer containing arabinoxylan and cellulose.The association of arabinoxylan and cellulose with penetration resistance suggests new targets for the improvement of papilla composition and enhanced disease resistance.


Via Christophe Jacquet
more...
Christophe Jacquet's curator insight, October 17, 7:08 AM

Nice work and great photos!

Rescooped by Guogen Yang from Plant-microbe interaction
Scoop.it!

A Unique Plant ESCRT Component, FREE1, Regulates Multivesicular Body Protein Sorting and Plant Growth: Current Biology

A Unique Plant ESCRT Component, FREE1, Regulates Multivesicular Body Protein Sorting and Plant Growth: Current Biology | Plant-Microbe Interaction | Scoop.it
Highlights•FREE1 is a plant-specific and PVC-localized FYVE domain protein binding to PI3P•FREE1 is in a complex with ESCRT-I via a direct interaction with Vps23•FREE1 directly binds to ubiquitin and regulates vacuolar membrane protein sorting•FREE1 is essential for PVC/MVB biogenesis and plant growthSummary

Tight control of membrane protein homeostasis by selective degradation is crucial for proper cell signaling and multicellular organismal development. Membrane proteins destined for degradation, such as misfolded proteins or activated receptors, are usually ubiquitinated and sorted into the intraluminal vesicles (ILVs) of prevacuolar compartments/multivesicular bodies (PVCs/MVBs), which then fuse with vacuoles/lysosomes to deliver their contents to the lumen for degradation by luminal proteases [ 1 ]. The formation of ILVs and the sorting of ubiquitinated membrane cargoes into them are facilitated by the endosomal sorting complex required for transport (ESCRT) machinery [ 2–4 ]. Plants possess most evolutionarily conserved members of the ESCRT machinery but apparently lack orthologs of ESCRT-0 subunits and the ESCRT-I component Mvb12 [ 5–8 ]. Here, we identified a unique plant ESCRT component called FYVE domain protein required for endosomal sorting 1 (FREE1). FREE1 binds to phosphatidylinositol-3-phosphate (PI3P) and ubiquitin and specifically interacts with Vps23 via PTAP-like tetrapeptide motifs to be incorporated into the ESCRT-I complex. Arabidopsis free1 mutant is seedling lethal and defective in the formation of ILVs in MVBs. Consequently, endocytosed plasma membrane (PM) proteins destined for degradation, such as the auxin efflux carrier PIN2 [ 9, 10 ], cannot reach the lumen of the vacuole and mislocalize to the tonoplast. Collectively, our findings provide the first functional characterization of a plant FYVE domain protein, which is essential for plant growth via its role as a unique evolutionary ESCRT component for MVB biogenesis and vacuolar sorting of membrane proteins.


Via Suayib Üstün
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interactions (on the plant's side)
Scoop.it!

Dissecting the Transcriptional Response to Elicitors in Vitis vinifera Cells

Dissecting the Transcriptional Response to Elicitors in Vitis vinifera Cells | Plant-Microbe Interaction | Scoop.it
The high effectiveness of cyclic oligosaccharides like cyclodextrins in the production of trans-resveratrol in Vitis vinifera cell cultures is enhanced in the presence of methyl jasmonate. In order to dissect the basis of the interactions among the elicitation responses triggered by these two compounds, a transcriptional analysis of grapevine cell cultures treated with cyclodextrins and methyl jasmonate separately or in combination was carried out. The results showed that the activation of genes encoding enzymes from phenylpropanoid and stilbene biosynthesis induced by cyclodextrins alone was partially enhanced in the presence of methyl jasmonate, which correlated with their effects on trans-resveratrol production. In addition, protein translation and cell cycle regulation were more highly repressed in cells treated with cyclodextrins than in those treated with methyl jasmonate, and this response was enhanced in the combined treatment. Ethylene signalling was activated by all treatments, while jasmonate signalling and salicylic acid conjugation were activated only in the presence of methyl jasmonate and cyclodextrins, respectively. Moreover, the combined treatment resulted in a crosstalk between the signalling cascades activated by cyclodextrins and methyl jasmonate, which, in turn, provoked the activation of additional regulatory pathways involving the up-regulation of MYB15, NAC and WRKY transcription factors, protein kinases and calcium signal transducers. All these results suggest that both elicitors cause an activation of the secondary metabolism in detriment of basic cell processes like the primary metabolism or cell division. Crosstalk between cyclodextrins and methyl jasmonate-induced signalling provokes an intensification of these responses resulting in a greater trans-resveratrol production.

Via Christophe Jacquet
more...
No comment yet.
Rescooped by Guogen Yang from MycorWeb Plant-Microbe Interactions
Scoop.it!

Nutrient computation for root architecture

Nutrient computation for root architecture | Plant-Microbe Interaction | Scoop.it

Nitrogen is a major limiting nutrient for plants. Root systems acquire nitrogen through uptake of nutrients such as nitrate from the soil. Some plants can also obtain nitrogen by establishing a root nodule symbiosis with N-fixing bacteria. Whatever the means to acquire nutrients, an investment of the plant is required in which root architecture is suitably adapted. Therefore, plants integrate local and global nutrient cues to spend resources efficiently. On page 343 in this Science issue, Tabata et al. (1) identify a peptide signaling mechanism by which the root locally senses N limitation in the soil, and communicates with the shoot, which then signals back to the root to stimulate lateral root growth in regions with a high nitrate content to facilitate nitrate uptake.


Via Francis Martin
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interaction
Scoop.it!

Myosins VIII and XI Play Distinct Roles in Reproduction and Transport of Tobacco Mosaic Virus

Myosins VIII and XI Play Distinct Roles in Reproduction and Transport of Tobacco Mosaic Virus | Plant-Microbe Interaction | Scoop.it
Viruses are obligatory parasites that depend on host cellular factors for their replication as well as for their local and systemic movement to establish infection. Although myosin motors are thought to contribute to plant virus infection, their exact roles in the specific infection steps have not been addressed. Here we investigated the replication, cell-to-cell and systemic spread of Tobacco mosaic virus (TMV) using dominant negative inhibition of myosin activity. We found that interference with the functions of three class VIII myosins and two class XI myosins significantly reduced the local and long-distance transport of the virus. We further determined that the inactivation of myosins XI-2 and XI-K affected the structure and dynamic behavior of the ER leading to aggregation of the viral movement protein (MP) and to a delay in the MP accumulation in plasmodesmata (PD). The inactivation of myosin XI-2 but not of myosin XI-K affected the localization pattern of the 126k replicase subunit and the level of TMV accumulation. The inhibition of myosins VIII-1, VIII-2 and VIII-B abolished MP localization to PD and caused its retention at the plasma membrane. These results suggest that class XI myosins contribute to the viral propagation and intracellular trafficking, whereas myosins VIII are specifically required for the MP targeting to and virus movement through the PD. Thus, TMV appears to recruit distinct myosins for different steps in the cell-to-cell spread of the infection.

Via Suayib Üstün
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interactions (on the plant's side)
Scoop.it!

Experimental approaches to study plant cell walls during plant-microbe interactions

Plant cell walls provide physical strength, regulate the passage of bio-molecules, and act as the first barrier of defense against biotic and abiotic stress. In addition to providing structural integrity, plant cell walls serve an important function in connecting cells to their extracellular environment by sensing and transducing signals to activate cellular responses, such as those that occur during pathogen infection. This mini review will summarize current experimental approaches used to study cell wall functions during plant-pathogen interactions. Focus will be paid to cell imaging, spectroscopic analyses, and metabolic profiling techniques.


Via Christophe Jacquet
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interaction
Scoop.it!

Dss1 Is a 26S Proteasome Ubiquitin Receptor

Dss1 Is a 26S Proteasome Ubiquitin Receptor | Plant-Microbe Interaction | Scoop.it
Summary

The ubiquitin-proteasome system is the major pathway for protein degradation in eukaryotic cells. Proteins to be degraded are conjugated to ubiquitin chains that act as recognition signals for the 26S proteasome. The proteasome subunits Rpn10 and Rpn13 are known to bind ubiquitin, but genetic and biochemical data suggest the existence of at least one other substrate receptor. Here, we show that the phylogenetically conserved proteasome subunit Dss1 (Sem1) binds ubiquitin chains linked by K63 and K48. Atomic resolution data show that Dss1 is disordered and binds ubiquitin by binding sites characterized by acidic and hydrophobic residues. The complementary binding region in ubiquitin is composed of a hydrophobic patch formed by I13, I44, and L69 flanked by two basic regions. Mutations in the ubiquitin-binding site of Dss1 cause growth defects and accumulation of ubiquitylated proteins.

Via Christophe Jacquet, Suayib Üstün
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interactions (on the plant's side)
Scoop.it!

Frontiers | Methanol and ethanol modulate responses to danger- and microbe-associated molecular patterns | Plant-Microbe Interaction

Frontiers | Methanol and ethanol modulate responses to danger- and microbe-associated molecular patterns | Plant-Microbe Interaction | Plant-Microbe Interaction | Scoop.it
Methanol is a byproduct of cell wall modification, released through the action of pectin methylesterases (PMEs), which demethylesterify cell wall pectins. Plant PMEs play not only a role in developmental processes but also in responses to herbivory and infection by fungal or bacterial pathogens. Molecular mechanisms that explain how methanol affects plant defenses are poorly understood. Here we show that exogenously supplied methanol alone has weak effects on defense signaling in three dicot species, however, it profoundly alters signaling responses to danger- and microbe-associated molecular patterns (DAMPs, MAMPs) such as the alarm hormone systemin, the bacterial flagellum-derived flg22 peptide, and the fungal cell wall-derived oligosaccharide chitosan. In the presence of methanol the kinetics and amplitudes of DAMP/MAMP-induced MAP kinase (MAPK) activity and oxidative burst are altered in tobacco and tomato suspension-cultured cells, in Arabidopsis seedlings and tomato leaf tissue. As a possible consequence of altered DAMP/MAMP signaling, methanol suppressed the expression of the defense genes PR-1 and PI-1 in tomato. In cell cultures of the grass tall fescue (Festuca arundinacea, Poaceae, Monocots), methanol alone activates MAPKs and increases chitosan-induced MAPK activity, and in the darnel grass Lolium temulentum (Poaceae), it alters wound-induced MAPK signaling. We propose that methanol can be recognized by plants as a sign of the damaged self. In dicots, methanol functions as a DAMP-like alarm signal with little elicitor activity on its own, whereas it appears to function as an elicitor-active DAMP in monocot grasses. Ethanol had been implicated in plant stress responses, although the source of ethanol in plants is not well established. We found that it has a similar effect as methanol on responses to MAMPs and DAMPs.

Via Christophe Jacquet
more...
No comment yet.
Rescooped by Guogen Yang from Virology and Bioinformatics from Virology.ca
Scoop.it!

Ebola by the numbers: The size, spread and cost of an outbreak

Ebola by the numbers: The size, spread and cost of an outbreak | Plant-Microbe Interaction | Scoop.it
As the virus continues to rampage in West Africa, Nature’s graphic offers a guide to the figures that matter.

Via burkesquires
more...
No comment yet.
Rescooped by Guogen Yang from Plant-Microbe Symbioses
Scoop.it!

From soil to plant, the journey of P through trophic relationships and ectomycorrhizal association

From soil to plant, the journey of P through trophic relationships and ectomycorrhizal association | Plant-Microbe Interaction | Scoop.it
Phosphorus (P) is essential for plant growth and productivity. It is one of the most limiting macronutrients in soil because it is mainly present as unavailable, bound P whereas plants can only use unbound, inorganic phosphate (Pi), which is found in very low concentrations in soil solution. Some ectomycorrhizal fungi are able to release organic compounds (organic anions or phosphatases) to mobilize unavailable P. Recent studies suggest that bacteria play a major role in the mineralization of nutrients such as P through trophic relationships as they can produce specific phosphatases such as phytases to degrade phytate, the main form of soil organic P. Bacteria are also more effective than other microorganisms or plants at immobilizing free Pi. Therefore, bacterial grazing by grazers, such as nematodes, could release Pi locked in bacterial biomass. Free Pi may be taken up by ectomycorrhizal fungus by specific phosphate transporters and transferred to the plant by mechanisms that have not yet been identified. This mini-review aims to follow the phosphate pathway to understand the ecological and molecular mechanisms responsible for transfer of phosphate from the soil to the plant, to improve plant P nutrition.

Via Jean-Michel Ané
more...
No comment yet.