Plant-Microbe Int...
Follow
Find
18.4K views | +27 today
 
Scooped by Guogen Yang
onto Plant-Microbe Interaction
Scoop.it!

ScienceDirect.com - Journal of Proteomics - In-depth insight into in vivo apoplastic secretome of rice-Magnaporthe oryzae interaction

ScienceDirect.com - Journal of Proteomics - In-depth insight into in vivo apoplastic secretome of rice-Magnaporthe oryzae interaction | Plant-Microbe Interaction | Scoop.it

The in vivo apoplastic fluid secretome of rice-blast fungus interaction remains largely uncharacterized. Here, we report a proteomics investigation of in vivo secreted proteins of rice leaves infected with incompatible (KJ401) and compatible (KJ301) races of Magnaporthe oryzae (M. oryzae) using 2-DGE and MudPIT coupled with MALDI-TOF-MS and/or nESI-LC–MS/MS analyses. Prepared fractions of secretory proteins were essentially free from cytoplasmic contamination. Two-DGE and MudPIT identified 732 secretory proteins, where 291 (40%) and 441 (60%) proteins were derived from rice and M. oryzae, respectively. Of these, 39.2% (rice) and 38.9% (M. oryzae) of proteins were predicted by SignalP as retaining signal peptides. Among these, rice secreted more proteins related to stress response, ROS and energy metabolism, whereas, M. oryzae secreted more proteins involved in metabolism and cell wall hydrolyses. Semi-quantitative RT-PCR revealed their differential expression under compatible/incompatible interactions. In vivo expression of M. oryzae glycosyl hydrolase (GH) protein family members using particle bombardment driven transient expression system showed that four GH genes could act as effectors within host apoplast possibly via interaction with host membrane bound receptor. The established in vivo secretome serves as a valuable resource toward secretome analysis of rice-M. oryzae interaction.

more...
No comment yet.

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 legume symbiosis
Scoop.it!

Use of enhancer trapping to identify pathogen-induced regulatory events spatially restricted to plant-microbe interaction sites

Use of enhancer trapping to identify pathogen-induced regulatory events spatially restricted to plant-microbe interaction sites | Plant-Microbe Interaction | Scoop.it
Plant genes differentially expressed during plant/pathogen interactions can be important for host immunity or contribute to pathogen virulence. Large-scale transcript profiling studies, such as microarray- or mRNA-seq-based analyses, have revealed hundreds of genes that are differentially expressed during plant/pathogen interactions. However, transcriptional responses limited to a small number of cells at infection sites can be difficult to detect by these approaches, as they are under-represented in the whole tissue data sets typically generated by such methods. This study examined interactions between Arabidopsis thaliana (Arabidopsis) and the pathogenic oomycete Hyaloperonospora arabidopsidis (Hpa) by enhancer trapping to uncover novel plant genes involved in local infection responses. We screened a β-glucoronidase (GUS) reporter-based enhancer-trap population for expression patterns related to Hpa infection. Several independent lines exhibited GUS expression in leaf mesophyll cells surrounding Hpa structures, indicating a regulatory response to pathogen infection. One of these lines contains a single enhancer-trap insertion in an exon of At1g08800 (MyoB1, Myosin Binding Protein 1) and was subsequently found to exhibit reduced susceptibility to Hpa. Two additional Arabidopsis lines with T-DNA insertions in exons of MyoB1 also exhibited approximately 30% fewer spores than wild type plants. This study demonstrates that our enhancer-trapping strategy can result in the identification of functionally-relevant pathogen-responsive genes. Our results further suggest that MyoB1 either positively contributes to Hpa virulence or negatively affects host immunity against this pathogen.

Via Christophe Jacquet
more...
No comment yet.
Rescooped by Guogen Yang from Plants and Microbes
Scoop.it!

Scientific Reports: Function and evolution of Magnaporthe oryzae avirulence gene AvrPib responding to the rice blast resistance gene Pib (2015)

Scientific Reports: Function and evolution of Magnaporthe oryzae avirulence gene AvrPib responding to the rice blast resistance gene Pib (2015) | Plant-Microbe Interaction | Scoop.it

Magnaporthe oryzae (Mo) is the causative pathogen of the damaging disease rice blast. The effector gene AvrPib, which confers avirulence to host carrying resistance gene Pib, was isolated via map-based cloning. The gene encodes a 75-residue protein, which includes a signal peptide. Phenotyping and genotyping of 60 isolates from each of five geographically distinct Mo populations revealed that the frequency of virulent isolates, as well as the sequence diversity within the AvrPib gene increased from a low level in the far northeastern region of China to a much higher one in the southern region, indicating a process of host-driven selection. Resequencing of the AvrPiballele harbored by a set of 108 diverse isolates revealed that there were four pathoways, transposable element (TE) insertion (frequency 81.7%), segmental deletion (11.1%), complete absence (6.7%), and point mutation (0.6%), leading to loss of the avirulence function. The lack of any TE insertion in a sample of non-rice infecting Moisolates suggested that it occurred after the host specialization of Mo. Both the deletions and the functional point mutation were confined to the signal peptide. The reconstruction of 16 alleles confirmed seven functional nucleotide polymorphisms for the AvrPiballeles, which generated three distinct expression profiles.


Via Kamoun Lab @ TSL
more...
No comment yet.
Rescooped by Guogen Yang from Plant immunity and legume symbiosis
Scoop.it!

Bradyrhizobium BclA is a peptide transporter required for bacterial differentiation in symbiosis with Aeschynomene legume

Bradyrhizobium BclA is a peptide transporter required for bacterial differentiation in symbiosis with Aeschynomene legume | Plant-Microbe Interaction | Scoop.it
Nodules of legume plants are highly integrated symbiotic systems shaped by millions of years of evolution. They harbor nitrogen fixing rhizobium bacteria called bacteroids. Several legume species produce peptides called NCRs in the symbiotic nodule cells which house the bacteroids. NCRs are related to antimicrobial peptides of innate immunity. They induce the endosymbionts into a differentiated, enlarged and polyploid state. The bacterial symbionts on their side evolved functions for the response to the NCR peptides. Here we identified the bclA gene of Bradyrhizobium strains ORS278 and ORS285 which is required for the formation of differentiated and functional bacteroids in the nodules of the NCR-producing Aeschynomene legumes. The BclA ABC transporter promotes the import of NCR peptides and provides protection against the antimicrobial activity of these peptides. Moreover, BclA can complement the role of the related BacA transporter of Sinorhizobium meliloti which has a similar symbiotic function in the interaction with Medicago legumes.

Via Christophe Jacquet
more...
No comment yet.
Rescooped by Guogen Yang from Plant immunity and legume symbiosis
Scoop.it!

Changing SERKs and priorities during plant life: Trends in Plant Science

Changing SERKs and priorities during plant life: Trends in Plant Science | Plant-Microbe Interaction | Scoop.it
SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASES (SERKs) are coreceptors for diverse extracellular signals. SERKs are involved in a wide array of developmental and immune related processes first discovered in Arabidopsis. Recent work demonstrates the evolutionary conservation of SERKs in all multicellular plants, and highlights their functional conservation in monocots and dicots.

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

Chloroplast Stromules Function during Innate Immunity: Developmental Cell

Chloroplast Stromules Function during Innate Immunity: Developmental Cell | Plant-Microbe Interaction | Scoop.it

•Chloroplast stromules are induced during plant immune responses•Pro-PCD signals such as SA and H2O2 induce stromules•Stromules form dynamic connections with nucleus during immune responses•Constitutively induced stromules enhance PCD during plant immune responses

 

Summary

Inter-organellar communication is vital for successful innate immune responses that confer defense against pathogens. However, little is known about how chloroplasts, which are a major production site of pro-defense molecules, communicate and coordinate with other organelles during defense. Here we show that chloroplasts send out dynamic tubular extensions called stromules during innate immunity or exogenous application of the pro-defense signals, hydrogen peroxide (H2O2) and salicylic acid. Interestingly, numerous stromules surround nuclei during defense response, and these connections correlate with an accumulation of chloroplast-localized NRIP1 defense protein and H2O2 in the nucleus. Furthermore, silencing and knockout ofchloroplast unusual positioning 1 (CHUP1) that encodes a chloroplast outer envelope protein constitutively induces stromules in the absence of pathogen infection and enhances programmed cell death. These results support a model in which stromules aid in the amplification and/or transport of pro-defense signals into the nucleus and other subcellular compartments during immunity.


Via Jennifer Mach, Suayib Üstün
more...
No comment yet.
Rescooped by Guogen Yang from Plant-Microbe Symbioses
Scoop.it!

Chromatin-based control of effector gene expression in plant-associated fungi

Plant-associated fungi often present in their genome areas enriched in repeat sequences and effector genes, the latter being specifically induced in planta. The location of effector genes in regions enriched in repeats has been shown to have an impact on adaptability of fungi but could also provide for tight control of effector gene expression through chromatin-based regulation. The distribution of two repressive histone marks was shown to be an important regulatory layer in two fungal species with different lifestyles. Chromatin-based control of effector gene expression is likely to provide an evolutionary advantage by preventing the expression of genes not needed during vegetative growth and allow for a massive concerted expression at particular time-points of plant infection.

Via Jean-Michel Ané
more...
No comment yet.
Rescooped by Guogen Yang from Virology and Bioinformatics from Virology.ca
Scoop.it!

Plant virus replication and movement

Plant virus replication and movement | Plant-Microbe Interaction | Scoop.it
Because plant cells are not identical to animal cells, plant viruses are significantly different from animal viruses in several ways.

Via Ed Rybicki
more...
No comment yet.
Rescooped by Guogen Yang from Plant Biology Teaching Resources (Higher Education)
Scoop.it!

Easy come, easy go: capillary forces enable rapid refilling of embolized primary xylem vessels.

Easy come, easy go: capillary forces enable rapid refilling of embolized primary xylem vessels. | Plant-Microbe Interaction | Scoop.it

"Easy come, easy go: capillary forces enable rapid refilling of embolized primary xylem vessels" - Beautifully illustrated study demonstrates that protoxylem serves as a fuse to protect other tissues from embolism, but also readily repairs embolisms when water becomes available.
"Thus, while protoxylem may be an “Achilles’ heel” for stem function under extreme conditions, they may also promote recovery of function upon rewatering. In this sense, their “easy come, easy go” behavior may offer more benefits than detriments to the integrated function of plants in complex, highly variable environments."



Via Mary Williams
more...
No comment yet.
Rescooped by Guogen Yang from How microbes emerge
Scoop.it!

PNAS: The butterfly plant arms-race escalated by gene and genome duplications (2015)

PNAS: The butterfly plant arms-race escalated by gene and genome duplications (2015) | Plant-Microbe Interaction | Scoop.it

Coevolutionary interactions are thought to have spurred the evolution of key innovations and driven the diversification of much of life on Earth. However, the genetic and evolutionary basis of the innovations that facilitate such interactions remains poorly understood. We examined the coevolutionary interactions between plants (Brassicales) and butterflies (Pieridae), and uncovered evidence for an escalating evolutionary arms-race. Although gradual changes in trait complexity appear to have been facilitated by allelic turnover, key innovations are associated with gene and genome duplications. Furthermore, we show that the origins of both chemical defenses and of molecular counter adaptations were associated with shifts in diversification rates during the arms-race. These findings provide an important connection between the origins of biodiversity, coevolution, and the role of gene and genome duplications as a substrate for novel traits.

 

See also blog post https://decodingscience.missouri.edu/2015/06/22/scientists-uncover-how-caterpillars-created-condiments/


Via Kamoun Lab @ TSL, Niklaus Grunwald
more...
No comment yet.
Rescooped by Guogen Yang from Plant-microbe interaction
Scoop.it!

Two serine residues in Pseudomonas syringae effector HopZ1a are required for acetyltransferase activity and association with the host co-factor - Ma - 2015 - New Phytologist - Wiley Online Library

Two serine residues in Pseudomonas syringae effector HopZ1a are required for acetyltransferase activity and association with the host co-factor - Ma - 2015 - New Phytologist - Wiley Online Library | Plant-Microbe Interaction | Scoop.it
Summary
Gram-negative bacteria inject type III secreted effectors (T3SEs) into host cells to manipulate the immune response. The YopJ family effector HopZ1a produced by the plant pathogen Pseudomonas syringae possesses acetyltransferase activity and acetylates plant proteins to facilitate infection.
Using mass spectrometry, we identified a threonine residue, T346, as the main autoacetylation site of HopZ1a. Two neighboring serine residues, S349 and S351, are required for the acetyltransferase activity of HopZ1a in vitro and are indispensable for the virulence function of HopZ1a in Arabidopsis thaliana.
Using proton nuclear magnetic resonance (NMR), we observed a conformational change of HopZ1a in the presence of inositol hexakisphosphate (IP6), which acts as a eukaryotic co-factor and significantly enhances the acetyltransferase activity of several YopJ family effectors. S349 and S351 are required for IP6-binding-mediated conformational change of HopZ1a.
S349 and S351 are located in a conserved region in the C-terminal domain of YopJ family effectors. Mutations of the corresponding serine(s) in two other effectors, HopZ3 of P. syringae and PopP2 of Ralstonia solanacerum, also abolished their acetyltransferase activity. These results suggest that, in addition to the highly conserved catalytic residues, YopJ family effectors also require conserved serine(s) in the C-terminal domain for their enzymatic activity.

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

An integrated database of wood-formation related genes in plants : Scientific Reports : Nature Publishing Group

An integrated database of wood-formation related genes in plants : Scientific Reports : Nature Publishing Group | Plant-Microbe Interaction | Scoop.it

Wood, which consists mainly of plant cell walls, is an extremely important resource in daily lives. Genes whose products participate in the processes of cell wall and wood formation are therefore major subjects of plant science research. The Wood-Formation Related Genes database (WFRGdb, http://me.lzu.edu.cn/woodformation/) serves as a data resource center for genes involved in wood formation. To create this database, we collected plant genome data published in other online databases and predicted all cell wall and wood formation related genes using BLAST and HMMER. To date, 47 gene families and 33 transcription factors from 57 genomes (28 herbaceous, 22 woody and 7 non-vascular plants) have been covered and more than 122,000 genes have been checked and recorded. To provide easy access to these data, we have developed several search methods, which make it easy to download targeted genes or groups of genes free of charge in FASTA format. Sequence and phylogenetic analyses are also available online. WFRGdb brings together cell wall and wood formation related genes from all available plant genomes, and provides an integrative platform for gene inquiry, downloading and analysis. This database will therefore be extremely useful for those who focuses on cell wall and wood research.


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

Redox rhythm reinforces the circadian clock to gate immune response : Nature : Nature Publishing Group

Redox rhythm reinforces the circadian clock to gate immune response : Nature : Nature Publishing Group | Plant-Microbe Interaction | Scoop.it
Recent studies have shown that in addition to the transcriptional circadian clock, many organisms, including Arabidopsis, have a circadian redox rhythm driven by the organism’s metabolic activities1, 2, 3. It has been hypothesized that the redox rhythm is linked to the circadian clock, but the mechanism and the biological significance of this link have only begun to be investigated4, 5, 6, 7. Here we report that the master immune regulator NPR1 (non-expressor of pathogenesis-related gene 1) of Arabidopsis is a sensor of the plant’s redox state and regulates transcription of core circadian clock genes even in the absence of pathogen challenge. Surprisingly, acute perturbation in the redox status triggered by the immune signal salicylic acid does not compromise the circadian clock but rather leads to its reinforcement. Mathematical modelling and subsequent experiments show that NPR1 reinforces the circadian clock without changing the period by regulating both the morning and the evening clock genes. This balanced network architecture helps plants gate their immune responses towards the morning and minimize costs on growth at night. Our study demonstrates how a sensitive redox rhythm interacts with a robust circadian clock to ensure proper responsiveness to environmental stimuli without compromising fitness of the organism.

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

Broad-spectrum antivirals against viral fusion : Nature Reviews Microbiology : Nature Publishing Group

Broad-spectrum antivirals against viral fusion : Nature Reviews Microbiology : Nature Publishing Group | Plant-Microbe Interaction | Scoop.it

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

Maternal effects on tree phenotypes: considering the microbiome

Maternal effects on tree phenotypes: considering the microbiome | Plant-Microbe Interaction | Scoop.it
The biotic and abiotic environmental experience of plants can influence the offspring without any changes in DNA sequence. These effects can modulate the development of the progeny and their interaction with microorganisms. This interaction includes fungal endophytic communities which have significant effects on trees and their associated ecosystems. In this opinion article, we highlight potential maternal mechanisms through which endophytes could influence the progeny. We argue that a better understanding of these interactions might help to predict the response of trees to stress conditions and enhance the efficiency of tree breeding programs.

Via Christophe Jacquet, Jean-Michel Ané
more...
No comment yet.
Rescooped by Guogen Yang from Plants and Microbes
Scoop.it!

Plant J: Crystal structure of the effector AvrLm4-7 of Leptosphaeria maculans reveals insights into its translocation into plant cell and recognition by resistance proteins (2015)

Plant J: Crystal structure of the effector AvrLm4-7 of Leptosphaeria maculans reveals insights into its translocation into plant cell and recognition by resistance proteins (2015) | Plant-Microbe Interaction | Scoop.it

The avirulence gene AvrLm4-7 of Leptosphaeria maculans, the causal agent of stem canker of oilseed rape, confers a dual specificity of recognition by two resistance genes (Rlm4 and Rlm7) and is strongly involved in fungal fitness. In order to elucidate the biological function of AvrLm4-7 and understand the specificity of recognition by Rlm4 and Rlm7, the AvrLm4-7 protein was produced in Pichia pastoris and its crystal structure determined. It revealed the presence of four disulfide bridges but no close structural analogs could be identified. A short stretch of amino acids in the C-terminus of the protein, (R/N)(Y/F)(R/S)E(F/W), was well-conserved among AvrLm4-7 homologs. Loss of recognition of AvrLm4-7 by Rlm4 is due to mutation of a single glycine to an arginine residue located in a loop of the protein. Loss of recognition by Rlm7 is governed by more complex mutational patterns, including gene loss or drastic modifications of the protein structure. Three point mutations altered residues in the well-conserved C-terminal motif or close to the glycine involved in Rlm4-mediated recognition, resulted in a loss of Rlm7-mediated recognition. Transient expression in tobacco and particle bombardment experiments on oilseed rape leaves suggested that AvrLm4-7 interacts with its cognate R proteins inside the plant cell, and can be translocated into plant cells in the absence of the pathogen. Translocation of AvrLm4-7 into oilseed rape leaves likely requires the (R/N)(Y/F)(R/S)E(F/W) motif as well as a RAWG motif located in a nearby loop that together form a positively charged region.


Via Kamoun Lab @ TSL
more...
No comment yet.
Rescooped by Guogen Yang from Plant immunity and legume symbiosis
Scoop.it!

Role of plant growth regulators as chemical signals in plant–microbe interactions: a double edged sword

Role of plant growth regulators as chemical signals in plant–microbe interactions: a double edged sword | Plant-Microbe Interaction | Scoop.it
Highlights



Plant defense signaling pathways overlap and can act synergistically or antagonistically.


ABA is known for its role in abiotic stress response but also plays a role in defense.


ABA can positively or negatively impact plant resistance; usually high ABA levels lower resistance.


Fungi also produce ABA.


ABA may play a role in enhancing or accelerating fungal virulence.

Growth regulators act not only as chemicals that modulate plant growth but they also act as signal molecules under various biotic and abiotic stresses. Of all growth regulators, abscisic acid (ABA) is long known for its role in modulating plants response against both biotic and abiotic stress. Although the genetic information for ABA biosynthesis in plants is well documented, the knowledge about ABA biosynthesis in other organisms is still in its infancy. It is known that various microbes including bacteria produce and secrete ABA, but the overall functional significance of why ABA is synthesized by microbes is not known. Here we discuss the functional involvement of ABA biosynthesis by a pathogenic fungus. Furthermore, we propose that ABA biosynthesis in plant pathogenic fungi could be targeted for novel fungicidal discovery.

Via Christophe Jacquet
more...
No comment yet.
Rescooped by Guogen Yang from Plant immunity and legume symbiosis
Scoop.it!

Plant cysteine-rich peptides that inhibit pathogen growth and control rhizobial differentiation in legume nodules

Plant cysteine-rich peptides that inhibit pathogen growth and control rhizobial differentiation in legume nodules | Plant-Microbe Interaction | Scoop.it

Highlights•

Medicago truncatula has both typical defensins and defensin-like peptides.

Nodule Cys-rich peptides (NCRs) comprise the majority of defensin-like peptides in M. truncatula.

NCRs are plant effectors governing rhizobial bacteroid development in nodules.

Phylogenetic relatedness of defensins and NCRs is assessed.

Plants must co-exist with both pathogenic and beneficial microbes. Antimicrobial peptides with broad antimicrobial activities represent one of the first lines of defense against pathogens. Many plant cysteine-rich peptides with potential antimicrobial properties have been predicted. Amongst them, defensins and defensin-like peptides are the most abundant and plants can express several hundreds of them. In some rhizobial–legume symbioses special defensin-like peptides, the nodule-specific cysteine-rich (NCR) peptides have evolved in those legumes whose symbiotic partner terminally differentiates. In Medicago truncatula, >700 NCRs exist and collectively act as plant effectors inducing irreversible differentiation of rhizobia to nitrogen-fixing bacteroids. Cationic NCR peptides have a broad range of potent antimicrobial activities but do not kill the endosymbionts.


Via Christophe Jacquet
more...
No comment yet.
Rescooped by Guogen Yang from The science toolbox
Scoop.it!

Promoting an open research culture

Promoting an open research culture | Plant-Microbe Interaction | Scoop.it

Transparency, openness, and reproducibility are readily recognized as vital features of science (1, 2). When asked, most scientists embrace these features as disciplinary norms and values (3). Therefore, one might expect that these valued features would be routine in daily practice. Yet, a growing body of evidence suggests that this is not the case (4–6).

A likely culprit for this disconnect is an academic reward system that does not sufficiently incentivize open practices (7). In the present reward system, emphasis on innovation may undermine practices that support verification. Too often, publication requirements (whether actual or perceived) fail to encourage transparent, open, and reproducible science (2, 4, 8, 9). For example, in a transparent science, both null results and statistically significant results are made available and help others more accurately assess the evidence base for a phenomenon. In the present culture, however, null results are published less frequently than statistically significant results (10) and are, therefore, more likely inaccessible and lost in the “file drawer” (11).


Via Niklaus Grunwald
more...
No comment yet.
Rescooped by Guogen Yang from Plant immunity and legume symbiosis
Scoop.it!

Chitin-mediated plant–fungal interactions: catching, hiding and handshaking

Chitin-mediated plant–fungal interactions: catching, hiding and handshaking | Plant-Microbe Interaction | Scoop.it

Highlights•

Plants recognize infecting fungi through the perception of released chitin fragments by LysM receptor complexes.

Pathogenic fungi secrete effectors and change their cell walls to escape from the chitin-mediated immune system.

Chitin-related molecules also serve as symbiotic signals in rhizobium/AM symbiosis.

Dual function of OsCERK1 in both chitin-mediated immunity and AM symbiosis sheds a new light on the evolutionary relationships between these systems.

Plants can detect infecting fungi through the perception of chitin oligosaccharides by lysin motif receptors such as CEBiP and CERK1. A major function of CERK1 seems to be as a signaling molecule in the receptor complex formed with ligand-binding molecules and to activate downstream defense signaling. Fungal pathogens, however, have developed counter strategies to escape from the chitin-mediated detection by using effectors and/or changing their cell walls. Common structural features between chitin and Nod-/Myc-factors and corresponding receptors have suggested the close relationships between the chitin-mediated immunity and rhizobial/arbuscular mycorrhizal symbiosis. The recent discovery of the dual function of OsCERK1 in both plant immunity and mycorrhizal symbiosis sheds new light on the evolutionary relationships between defense and symbiotic systems in plants.

Current Opinion in Plant Biology 2015, 26:xx–


Via Christophe Jacquet
more...
No comment yet.
Rescooped by Guogen Yang from Plant Biology Teaching Resources (Higher Education)
Scoop.it!

Morphinan biosynthesis in opium poppy requires a P450-oxidoreductase fusion protein

Morphinan biosynthesis in opium poppy requires a P450-oxidoreductase fusion protein | Plant-Microbe Interaction | Scoop.it

Morphinan biosynthesis in opium poppy requires a P450-oxidoreductase fusion protein.
Neat - one of catalytic steps in the production of morphine requires an enzyme that is different in morphine-producing plants (but not others). In these plants, genes encoding two enzymes are fused to encode a single polypetide. This fusion protein is thought to be more effective at the catalytic step, by passing the product from the first reaction directly to the catalytic site for the second reaction (substrate channelling).
It's interesting from the point of view of morphine biosynthesis but also as an example of a recent evolutionary change that enhances secondary metabolism, and also as an example of how synthetic biologists can tinker with enzymes to enhance certain biosynthetic pathways.
http://www.sciencemag.org/…/early/2015/06/24/science.aab1852


Via Mary Williams
more...
No comment yet.
Rescooped by Guogen Yang from Plant Biology Teaching Resources (Higher Education)
Scoop.it!

Comprehensive Tissue-specific Transcriptome Analysis Reveals Distinct Regulatory Programs During Early Tomato Fruit Development

Comprehensive Tissue-specific Transcriptome Analysis Reveals Distinct Regulatory Programs During Early Tomato Fruit Development | Plant-Microbe Interaction | Scoop.it

Laser capture microdissection coupled to high-throughput RNA-sequencing analysis of the transcriptome of ovaries and fruit tissues of the wild tomato species Solanum pimpinellifolium. Co-expressed gene clusters linked specific tissues and stages to major transcriptional changes underlying the ovary to fruit transition, and provided evidence of regulatory modules related to cell division, photosynthesis and auxin transport in internal fruit tissues, together with parallel specialization of the pericarp transcriptome in stress responses and secondary metabolism. Major alterations in the expression of hormone metabolic and signaling components illustrate the complex hormonal control underpinning fruit formation, with intricate spatiotemporal variations suggesting separate regulatory programs.


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

Frontiers | Auto-acetylation on K289 is not essential for HopZ1a-mediated plant defense suppression | Plant Biotic Interactions

The Pseudomonas syringae type III-secreted effector HopZ1a is a member of the HopZ / YopJ superfamily of effectors that triggers immunity in Arabidopsis. We have previously shown that HopZ1a suppresses both local (effector-triggered immunity, ETI) and systemic immunity (systemic acquired resistance, SAR) triggered by the heterologous effector AvrRpt2. HopZ1a has been shown to possess acetyltransferase activity, and this activity is essential to trigger immunity in Arabidopsis. HopZ1a acetyltransferase activity has been reported to require the auto-acetylation of the effector on a specific lysine (K289) residue. In this paper we analyze the relevance of autoacetylation of lysine residue 289 in HopZ1a ability to suppress plant defenses, and on the light of the results obtained, we also revise its relevance for HopZ1a avirulence activity. Our results indicate that, while the HopZ1aK289R mutant is impaired to some degree in its virulence and avirulence activities, is by no means phenotypically equivalent to the catalytically inactive HopZ1aC216A, since it is still able to trigger a defense response that induces detectable macroscopic HR and effectively protects Arabidopsis from infection, reducing growth of P. syringae within the plant. We also present evidence that the HopZ1aK289R mutant still displays virulence activities, partially suppressing both ETI and SAR.

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

Identification of novel Xanthomonas euvesicatoria type III effector proteins by a machine-learning approach - Teper - Molecular Plant Pathology - Wiley Online Library

Identification of novel Xanthomonas euvesicatoria type III effector proteins by a machine-learning approach - Teper - Molecular Plant Pathology - Wiley Online Library | Plant-Microbe Interaction | Scoop.it
The Gram-negative bacterium Xanthomonas euvesicatoria (Xcv) is the causal agent of bacterial spot disease in pepper and tomato. Xcv pathogenicity depends on a type III secretion (T3S) system that delivers effector proteins into host cells to suppress plant immunity and promote disease. The pool of known Xcv effectors includes approximately 30 proteins, most of them identified in the 85-10 strain by various experimental and computational techniques. To identify additional Xcv 85-10 effectors, we applied a genome-wide machine learning approach, in which all ORFs were scored according to their propensity to encode effectors. Scoring was based on a large set of features including genomic organization, taxonomical dispersion, hrp-dependent expression, 5’ regulatory sequences, amino acid composition bias, and GC content. Thirty-six predicted effectors were tested for translocation into plant cells by using the HR-inducing domain of AvrBs2 as a reporter. Seven proteins (XopAU, XopAV, XopAW, XopAP, XopAX, XopAK, and XopAD) harbored a functional translocation signal and their translocation relied on the HrpF translocon, indicating that they are bona fide T3S effectors. Remarkably, four of them belong to novel effector families. Inactivation of the xopAP gene reduced the severity of disease symptoms in infected plants. A decrease in cell death and chlorophyll content was observed in pepper leaves inoculated with the xopAP mutant as compared to the wild-type strain. However, populations of the xopAP mutant in infected leaves were similar in size to those of the wild-type bacteria, suggesting that the reduction in virulence was not due to an impaired bacterial growth.

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

The Genera of Fungi: fixing the application of type species of generic names

The Genera of Fungi: fixing the application of type species of generic names | Plant-Microbe Interaction | Scoop.it
To ensure a stable platform for fungal taxonomy, it is of paramount importance that the genetic application of generic names be based on their DNA sequence data, and wherever possible, not morphology or ecology alone. To facilitate this process, a new database, accessible at www.GeneraofFungi.org (GoF) was established, which will allow deposition of metadata linked to holo-, lecto-, neo- or epitype specimens, cultures and DNA sequence data of the type species of genera. Although there are presently more than 18 000 fungal genera described, we aim to initially focus on the subset of names that have been placed on the “Without-prejudice List of Protected Generic Names of Fungi” (see IMA Fungus 4(2): 381–443, 2013). To enable the global mycological community to keep track of typification events and avoid duplication, special MycoBank Typification identfiers (MBT) will be issued upon deposit of metadata in MycoBank. MycoBank is linked to GoF, thus deposited metadata of generic type species will be displayed in GoF (and vice versa), but will also be linked to Index Fungorum (IF) and the curated RefSeq Targeted Loci (RTL) database in GenBank at the National Center for Biotechnology Information (NCBI). This initial paper focuses on eight genera of appendaged coelomycetes, the type species of which are neo- or epitypified here: Bartalinia (Bartalinia robillardoides; Amphisphaeriaceae, Xylariales), Chaetospermum (Chaetospermum chaetosporum, incertae sedis, Sebacinales), Coniella (Coniella fragariae, Schizoparmaceae, Diaporthales), Crinitospora (Crinitospora pulchra, Melanconidaceae, Diaporthales), Eleutheromyces (Eleutheromyces subulatus, Helotiales), Kellermania (Kellermania yuccigena, Planistromataceae, Botryosphaeriales), Mastigosporium (Mastigosporium album, Helotiales), and Mycotribulus (Mycotribulus mirabilis, Agaricales). Authors interested in contributing accounts of individual genera to larger multi-authored papers to be published in IMA Fungus, should contact the associate editors listed below for the major groups of fungi on the List of Protected Generic Names for Fungi.

Via Elsa Ballini
more...
No comment yet.
Rescooped by Guogen Yang from Plant immunity and legume symbiosis
Scoop.it!

The ARGOS gene family functions in a negative feedback loop to desensitize plants to ethylene

The ARGOS gene family functions in a negative feedback loop to desensitize plants to ethylene | Plant-Microbe Interaction | Scoop.it

Background

Ethylene plays critical roles in plant growth and development, including the regulation of cell expansion, senescence, and the response to biotic and abiotic stresses. Elements of the initial signal transduction pathway have been determined, but we are still defining regulatory mechanisms by which the sensitivity of plants to ethylene is modulated.

Results

We report here that members of the ARGOS gene family of Arabidopsis, previously implicated in the regulation of plant growth and biomass, function as negative feedback regulators of ethylene signaling. Expression of all four members of the ARGOS family is induced by ethylene, but this induction is blocked in ethylene-insensitive mutants. The dose dependence for ethylene induction varies among the ARGOS family members, suggesting that they could modulate responses across a range of ethylene concentrations. GFP-fusions of ARGOS and ARL localize to the endoplasmic reticulum, the same subcellular location as the ethylene receptors and other initial components of the ethylene signaling pathway. Seedlings with increased expression of ARGOS family members exhibit reduced ethylene sensitivity based on physiological and molecular responses.

Conclusions

These results support a model in which the ARGOS gene family functions as part of a negative feedback circuit to desensitize the plant to ethylene, thereby expanding the range of ethylene concentrations to which the plant can respond. These results also indicate that the effects of the ARGOS gene family on plant growth and biomass are mediated through effects on ethylene signal transduction.

 

 


Via Christophe Jacquet
more...
No comment yet.