MycorWeb Plant-Microbe Interactions
84.3K views | +53 today
 
Rescooped by Francis Martin from Plant immunity and legume symbiosis
onto MycorWeb Plant-Microbe Interactions
Scoop.it!

Plant Cell Wall–Degrading Enzymes and Their Secretion in Plant-Pathogenic Fungi

Plant Cell Wall–Degrading Enzymes and Their Secretion in Plant-Pathogenic Fungi | MycorWeb Plant-Microbe Interactions | Scoop.it

Approximately a tenth of all described fungal species can cause diseases in plants. A common feature of this process is the necessity to pass through the plant cell wall, an important barrier against pathogen attack. To this end, fungi possess a diverse array of secreted enzymes to depolymerize the main structural polysaccharide components of the plant cell wall, i.e., cellulose, hemicellulose, and pectin. Recent advances in genomic and systems-level studies have begun to unravel this diversity and have pinpointed cell wall–degrading enzyme (CWDE) families that are specifically present or enhanced in plant-pathogenic fungi. In this review, we discuss differences between the CWDE arsenal of plant-pathogenic and non-plant-pathogenic fungi, highlight the importance of individual enzyme families for pathogenesis, illustrate the secretory pathway that transports CWDEs out of the fungal cell, and report the transcriptional regulation of expression of CWDE genes in both saprophytic and phytopathogenic fungi.


Via Christophe Jacquet
more...
No comment yet.
MycorWeb Plant-Microbe Interactions
Your new post is loading...
Your new post is loading...
Rescooped by Francis Martin from Plants & Evolution
Scoop.it!

Lipid transfer from plants to arbuscular mycorrhiza fungi

Arbuscular mycorrhiza (AM) symbioses contribute to global carbon cycles as plant hosts divert up to 20% of photosynthate to the obligate biotrophic fungi. Previous studies suggested carbohydrates as the only form of carbon transferred to the fungi. However, de novo fatty acid (FA) synthesis has not been observed in AM fungi in absence of the plant. In a forward genetic approach, we identified two Lotus japonicus mutants defective in AM-specific paralogs of lipid biosynthesis genes (KASI and GPAT6). These mutants perturb fungal development and accumulation of emblematic fungal 16:1ω5 FAs. Using isotopolog profiling we demonstrate that 13C patterns of fungal FAs recapitulate those of wild-type hosts, indicating cross-kingdom lipid transfer from plants to fungi. This transfer of labelled FAs was not observed for the AM-specific lipid biosynthesis mutants. Thus, growth and development of beneficial AM fungi is not only fueled by sugars but depends on lipid transfer from plant hosts.

Via Pierre-Marc Delaux
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Insights into the red algae and eukaryotic evolution from the genome of Porphyra umbilicalis (Bangiophyceae, Rhodophyta)

Insights into the red algae and eukaryotic evolution from the genome of Porphyra umbilicalis (Bangiophyceae, Rhodophyta) | MycorWeb Plant-Microbe Interactions | Scoop.it
Porphyra umbilicalis (laver) belongs to an ancient group of red algae (Bangiophyceae), is harvested for human food, and thrives in the harsh conditions of the upper intertidal zone. Here we present the 87.7-Mbp haploid Porphyra genome (65.8% G + C content, 13,125 gene loci) and elucidate traits that inform our understanding of the biology of red algae as one of the few multicellular eukaryotic lineages. Novel features of the Porphyra genome shared by other red algae relate to the cytoskeleton, calcium signaling, the cell cycle, and stress-tolerance mechanisms including photoprotection. Cytoskeletal motor proteins in Porphyra are restricted to a small set of kinesins that appear to be the only universal cytoskeletal motors within the red algae. Dynein motors are absent, and most red algae, including Porphyra, lack myosin. This surprisingly minimal cytoskeleton offers a potential explanation for why red algal cells and multicellular structures are more limited in size than in most multicellular lineages. Additional discoveries further relating to the stress tolerance of bangiophytes include ancestral enzymes for sulfation of the hydrophilic galactan-rich cell wall, evidence for mannan synthesis that originated before the divergence of green and red algae, and a high capacity for nutrient uptake. Our analyses provide a comprehensive understanding of the red algae, which are both commercially important and have played a major role in the evolution of other algal groups through secondary endosymbioses.
more...
No comment yet.
Rescooped by Francis Martin from Plants & Evolution
Scoop.it!

Calcium signatures and signaling events orchestrate plant–microbe interactions

Highlights 
• Microbe perception by PRRs directly activates Ca2+ channels/pumps and Ca2+ influx. 
• Activated PRRs indirectly activate Ca2+ channels/pumps via ROS or cNMP. 
• Elevated [Ca2+]cyt and oxidative bursts constitute a signaling amplification loop. 
• Ca2+ signals could be fed into transcriptional controls via Ca2+/CaM-regulated TFs. 
• Ca2+ signaling controls defense both positively and negatively at multiple stages. 

Calcium (Ca2+) acts as an essential second messenger connecting the perception of microbe signals to the establishment of appropriate immune and symbiotic responses in plants. Accumulating evidence suggests that plants distinguish different microorganisms through plasma membrane-localized pattern recognition receptors. The particular recognition events are encoded into Ca2+ signatures, which are sensed by diverse intracellular Ca2+ binding proteins. The Ca2+ signatures are eventually decoded to distinct downstream responses through transcriptional reprogramming of the defense or symbiosis-related genes. Recent observations further reveal that Ca2+-mediated signaling is also involved in negative regulation of plant immunity. This review is intended as an overview of Ca2+ signaling during immunity and symbiosis, including Ca2+ responses in the nucleus and cytosol.

Via Pierre-Marc Delaux
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Cell-specific expression of plant nutrient transporter genes in orchid mycorrhizae

Cell-specific expression of plant nutrient transporter genes in orchid mycorrhizae | MycorWeb Plant-Microbe Interactions | Scoop.it
Orchid mycorrhizal protocorms and roots are heterogeneous structures composed of different plant cell-types, where cells colonized by intracellular fungal coils (the pelotons) are close to non-colonized plant cells. Moreover, the fungal coils undergo rapid turnover inside the colonized cells, so that plant cells containing coils at different developmental stages can be observed in the same tissue section. Here, we have investigated by laser microdissection (LMD) the localization of specific plant gene transcripts in different cell-type populations collected from mycorrhizal protocorms and roots of the Mediterranean orchid Serapias vomeracea colonized by Tulasnella calospora. RNAs extracted from the different cell-type populations have been used to study plant gene expression, focusing on genes potentially involved in N uptake and transport and previously identified as up-regulated in symbiotic protocorms. Results clearly showed that some plant N transporters are differentially expressed in cells containing fungal coils at different developmental stages, as well as in non-colonized cells, and allowed the identification of new functional markers associated to coil-containing cells.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Modification of the nanostructure of lignocellulose cell walls via a non-enzymatic lignocellulose deconstruction system in brown rot wood-decay fungi

Modification of the nanostructure of lignocellulose cell walls via a non-enzymatic lignocellulose deconstruction system in brown rot wood-decay fungi | MycorWeb Plant-Microbe Interactions | Scoop.it
Wood decayed by brown rot fungi and wood treated with the chelator-mediated Fenton (CMF) reaction, either alone or together with a cellulose enzyme cocktail, was analyzed by small angle neutron scattering (SANS), sum frequency generation (SFG) spectroscopy, Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM). Results showed that the CMF mechanism mimicked brown rot fungal attack for both holocellulose and lignin components of the wood. Crystalline cellulose and lignin were both depolymerized by the CMF reaction. Porosity of the softwood cell wall did not increase during CMF treatment, enzymes secreted by the fungi did not penetrate the decayed wood. The enzymes in the cellulose cocktail also did not appear to alter the effects of the CMF-treated wood relative to enhancing cell wall deconstruction. This suggests a rethinking of current brown rot decay models and supports a model where monomeric sugars and oligosaccharides diffuse from the softwood cell walls during non-enzymatic action. In this regard, the CMF mechanism should not be thought of as a “pretreatment” used to permit enzymatic penetration into softwood cell walls, but instead it enhances polysaccharide components diffusing to fungal enzymes located in wood cell lumen environments during decay. SANS and other data are consistent with a model for repolymerization and aggregation of at least some portion of the lignin within the cell wall, and this is supported by AFM and TEM data. The data suggest that new approaches for conversion of wood substrates to platform chemicals in biorefineries could be achieved using the CMF mechanism with >75% solubilization of lignocellulose, but that a more selective suite of enzymes and other downstream treatments may be required to work when using CMF deconstruction technology. Strategies to enhance polysaccharide release from lignocellulose substrates for enhanced enzymatic action and fermentation of the released fraction would also aid in the efficient recovery of the more uniform modified lignin fraction that the CMF reaction generates to enhance biorefinery profitability.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Distribution and diversity of enzymes for polysaccharide degradation in fungi

Distribution and diversity of enzymes for polysaccharide degradation in fungi | MycorWeb Plant-Microbe Interactions | Scoop.it
Fungi are important polysaccharide degraders in the environment and for biotechnology. Here, the increasing number of sequenced fungal genomes allowed for systematic identification of genes and proteins involved in polysaccharide degradation in 218 fungi. Globally, 9,003 sequences for glycoside hydrolases and lytic polysaccharide mono-oxygenases targeting cellulose, xylan, and chitin, were identified. Although abundant in most lineages, the distribution of these enzymes is variable even between organisms from the same genus. However, most fungi are generalists possessing several enzymes for polysaccharide deconstruction. Most identified enzymes were small proteins with simple domain organization or eventually consisted of one catalytic domain associated with a non-catalytic accessory domain. Thus unlike bacteria, fungi's ability to degrade polysaccharides relies on apparent redundancy in functional traits and the high frequency of lytic polysaccharide mono-oxygenases, as well as other physiological adaptation such as hyphal growth. Globally, this study provides a comprehensive framework to further identify enzymes for polysaccharide deconstruction in fungal genomes and will help identify new strains and enzymes with potential for biotechnological application.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Biodiversité, combien de millions d’espèces ?

Biodiversité, combien de millions d’espèces ? | MycorWeb Plant-Microbe Interactions | Scoop.it
Après des siècles d’études, on pensait avoir au moins une idée approximative du nombre des différentes espèces vivant sur Terre. L’utilité d’un tel recensement est d’autant plus urgent que la biodiversité disparaît à une vitesse grandissante en raison des activités humaines. Des espèces vont s’éteindre avant même qu’on ne les découvre.

Les scientifiques ont répertorié près de 2 millions d’espèces, mais on estime le nombre total entre à 3 à 100 millions. Le consensus s’est fixé récemment au bas de la fourchette, avec une étude très popularisée qui a proposé un chiffre précis de 8,7 millions d’espèces (à l’exception des bactéries, trop compliquées à compter).

Si c’est bien le cas, on a accompli des progrès considérables en cataloguant la biodiversité de la planète en ayant effectué 20 % peut-être du travail.

Mais dans une correspondance publiée dans la revue Nature, nous estimons que ce consensus sous-estime la biodiversité terrestre d’un facteur dix. Auquel cas, la tâche de décrire et de comprendre la biodiversité s’avère plus herculéenne qu’on n’aurait jamais pu l’imaginer.

Depuis 300 ans que le naturaliste suédois Carolus Linnaeus s’est illustré comme pionnier en matière de classification scientifique, nous pourrions avoir désigné seulement 2 % de la biodiversité terrestre.
more...
No comment yet.
Rescooped by Francis Martin from The Plant Microbiome
Scoop.it!

Exposure to the leaf litter microbiome of healthy adults protects seedlings from pathogen damage

Exposure to the leaf litter microbiome of healthy adults protects seedlings from pathogen damage | MycorWeb Plant-Microbe Interactions | Scoop.it
It is increasingly recognized that microbiota affect host health and physiology. However, it is unclear what factors shape microbiome community assembly in nature, and how microbiome assembly can be manipulated to improve host health. All plant leaves host foliar endophytic fungi, which make up a diverse, environmentally acquired fungal microbiota. Here, we experimentally manipulated assembly of the cacao tree ( Theobroma cacao ) fungal microbiome in nature and tested the effect of assembly outcome on host health. Using next-generation sequencing, as well as culture-based methods coupled with Sanger sequencing, we found that manipulating leaf litter exposure and location within the forest canopy significantly altered microbiome composition in cacao. Exposing cacao seedlings to leaf litter from healthy conspecific adults enriched the seedling microbiome with Colletotrichum tropicale , a fungal endophyte known to enhance pathogen resistance of cacao seedlings by upregulating host defensive pathways. As a result, seedlings exposed to healthy conspecific litter experienced reduced pathogen damage. Our results link processes that affect the assembly and composition of microbiome communities to their functional consequences for host success, and have broad implications for understanding plant–microbe interactions. Deliberate manipulation of the plant–fungal microbiome also has potentially important applications for cacao production and other agricultural systems in general.

Via Stéphane Hacquard
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Fungal phytopathogens encode functional homologues of plant rapid alkalinization factor (RALF) peptides

Fungal phytopathogens encode functional homologues of plant rapid alkalinization factor (RALF) peptides | MycorWeb Plant-Microbe Interactions | Scoop.it
In this article, we describe the presence of genes encoding close homologues of an endogenous plant peptide, rapid alkalinization factor (RALF), within the genomes of 26 species of phytopathogenic fungi. Members of the RALF family are key growth factors in plants, and the sequence of the RALF active region is well conserved between plant and fungal proteins. RALF1-like sequences were observed in most cases; however, RALF27-like sequences were present in the Sphaerulina musiva and Septoria populicola genomes. These two species are pathogens of poplar and, interestingly, the closest relative to their respective RALF genes is a poplar RALF27-like sequence. RALF peptides control cellular expansion during plant development, but were originally defined on the basis of their ability to induce rapid alkalinization in tobacco cell cultures. To test whether the fungal RALF peptides were biologically active in plants, we synthesized RALF peptides corresponding to those encoded by two sequenced genomes of the tomato pathogen Fusarium oxysporum f. sp. lycopersici. One of these peptides inhibited the growth of tomato seedlings and elicited responses in tomato and Nicotiana benthamiana typical of endogenous plant RALF peptides (reactive oxygen species burst, induced alkalinization and mitogen-activated protein kinase activation). Gene expression analysis confirmed that a RALF-encoding gene in F. oxysporum f. sp. lycopersici was expressed during infection on tomato. However, a subsequent reverse genetics approach revealed that the RALF peptide was not required by F. oxysporum f. sp. lycopersici for infection on tomato roots. This study has demonstrated the presence of functionally active RALF peptides encoded within phytopathogens that harbour an as yet undetermined role in plant–pathogen interactions.
more...
No comment yet.
Rescooped by Francis Martin from Plant pathogenic fungi
Scoop.it!

Antifungal activities of wood extractives

Antifungal activities of wood extractives | MycorWeb Plant-Microbe Interactions | Scoop.it
Extractives are non-structural wood molecules that represent a minor fraction in wood. However, they are source of diverse molecules putatively bioactive. Inhibition of fungal growth is one of the most interesting properties of wood extractives in a context of wood preservation, crop protection or medical treatments. The antifungal effect of molecules isolated from wood extractives has been mainly attributed to various mechanisms such as metal and free radical scavenging activity, direct interaction with enzymes, disruption of membrane integrity and perturbation of ionic homeostasis. Lignolytic fungi, which are microorganisms adapted to wood substrates, have developed various strategies to protect themselves against this toxicity. A better knowledge of these strategies could help both developing new systems for extractive removal in biomass valorization processes and using these molecules as antifungal agents.


Via Steve Marek
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Wild emmer genome architecture and diversity elucidate wheat evolution and domestication

Wild emmer genome architecture and diversity elucidate wheat evolution and domestication | MycorWeb Plant-Microbe Interactions | Scoop.it
Modern wheat, which underlies the diet of many across the globe, has a long history of selection and crosses among different species. Avni et al. used the Hi-C method of genome confirmation capture to assemble and annotate the wild allotetraploid wheat ( Triticum turgidum ). They then identified the putative causal mutations in genes controlling shattering (a key domestication trait among cereal crops). They also performed an exome capture–based analysis of domestication among wild and domesticated genotypes of emmer wheat. The findings present a compelling overview of the emmer wheat genome and its usefulness in an agricultural context for understanding traits in modern bread wheat.

Science , this issue p. [93][1]

[1]: /lookup/doi/10.1126/science.aan0032
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Caught in the jump

Caught in the jump | MycorWeb Plant-Microbe Interactions | Scoop.it
Microbial pathogens of plants typically cause disease on a limited number of host species. In nature, pathogens rarely become pathogenic to a new host. The underlying mechanisms of such host jumps are poorly understood but are thought to be linked to the capacity of the pathogen to undermine immunity of the former nonhost species (1). On page 80 of this issue, Inoue et al. (2) report a host jump mechanism of a notorious pathogenic fungus, Pyricularia oryzae, which causes blast disease in cereals.

The immune system of plants consists of two branches. First, surface-resident pattern recognition receptors (PRRs) detect microbial epitopes that are often conserved among many microbial taxa. Second, intracellular nucleotide-binding and leucinerich repeat proteins (NLRs) detect the actions of polymorphic pathogen-delivered and virulence-promoting proteins, called effectors. Recognized effectors are denoted avirulence genes (AVRs). Pathogen effectors often work by subverting signaling initiated by PRRs, facilitating host colonization and disease. The effector arsenal varies between strains of a pathogen species and is a major determinant for adaptation to specific hosts.
more...
Dorian Q Fuller's curator insight, July 14, 6:18 AM
One of the poorly understood strands of the origins and spread of agriculture,is the origins of crop diseases, which must have be facilitated by the spread to new environments and the diversification of crop packages.
Rescooped by Francis Martin from Plant pathology satellites
Scoop.it!

Book: Fortress Plant- How to survive when everything wants to eat you (2017)

Book: Fortress Plant- How to survive when everything wants to eat you (2017) | MycorWeb Plant-Microbe Interactions | Scoop.it

The survival of plants on our planet is nothing short of miraculous. They are virtually stationary packages of food, providing sustenance for a vast array of organisms, ranging from bacteria and fungi, through to insects, and even other plants. But plants are master survivors, having coped with changing environments and evolving predators over much of the history of life on earth.

 

Looks at how plants defend themselves against a wide variety of attackers, such as big animals, tiny insects, fungi, and bacteria, using an arsenal of weaponsExplores the evolution of plant defences, showing how they have resulted from an arms race with attackers that has been raging for millions of yearsDescribes the approaches by which scientists learn about plant defencesConsiders how we can use our knowledge of plant defences to help protect our food crops and forests

Via Kamoun Lab @ TSL, Tofazzal Islam's Research Group, Elsa Ballini
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Population structure of an orchid mycorrhizal fungus with genus-wide specificity

Population structure of an orchid mycorrhizal fungus with genus-wide specificity | MycorWeb Plant-Microbe Interactions | Scoop.it
Fundamental life history processes of mycorrhizal fungi with inconspicuous fruiting bodies can be difficult to elucidate. In this study we investigated the species identities and life history of the orchid mycorrhizal Tulasnella fungi, which associate with the south eastern Australia orchid genus Chiloglottis. Tulasnella prima was the primary partner and was found to be associated with all 17 Chiloglottis species across a range of >1000 km, and to occur in the two edaphic conditions investigated (soil and sphagnum hammocks). Another Tulasnella species (T. sphagneti) appears to be restricted to moist conditions of alpine sphagnum hammocks. The population genetic structure of the widespread species T. prima, was investigated at 10 simple sequence repeat (SSR) markers and at four cross-amplified SSR loci for T. sphagneti. For both taxa, no sharing of multilocus genotypes was found between sites, but clones were found within sites. Evidence for inbreeding within T. prima was found at 3 of 5 sites. Significant genetic differentiation was found within and between taxa. Significant local positive spatial genetic autocorrelation was detected among non-clonal isolates at the scale of two metres. Overall, the population genetic patterns indicated that in Tulasnella mating occurs by inbreeding and dispersal is typically restricted to short-distances.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Climate scientists flock to France’s call

Climate scientists flock to France’s call | MycorWeb Plant-Microbe Interactions | Scoop.it
Hundreds of climate scientists, including many from the United States, have applied to work in France under a €60-million (US$69-million) scheme set up by the country's president, Emmanuel Macron, after his US counterpart Donald Trump rejected the Paris accord on global warming. And Germany has announced that it will set up a similar programme to lure researchers.

Macron launched his ‘Make Our Planet Great Again’ initiative on 8 June, seeking to entice researchers in other countries to France with offers of 4-year grants worth up to €1.5 million. Six weeks on, the programme has been flooded with applicants, says Anne Peyroche, a biologist and the chief research officer of the CNRS, France’s national basic-research agency.

"Applications continue to come in every hour," she says. Most applied for relatively short sabbaticals in France, but the 154 scientists attracted by longer-term stays of four years or more are of most interest to the initiative's organizers, Peyroche says. France is also headhunting some top climate scientists individually, she adds. The scheme will shortlist as many as 80 scientists by mid-September, with 50 or so winners to be announced around the end of November.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Complete Genome Sequence of the Phytopathogenic Fungus Sclerotinia sclerotiorum Reveals Insights into the Genome Architecture of Broad Host Range Pathogens

Complete Genome Sequence of the Phytopathogenic Fungus  Sclerotinia sclerotiorum  Reveals Insights into the Genome Architecture of Broad Host Range Pathogens | MycorWeb Plant-Microbe Interactions | Scoop.it
Sclerotinia sclerotiorum is a phytopathogenic fungus with over 400 hosts including numerous economically important cultivated species. This contrasts many economically destructive pathogens that only exhibit a single or very few hosts. Many plant pathogens exhibit a “two-speed” genome. So described because their genomes contain alternating gene rich, repeat sparse and gene poor, repeat-rich regions. In fungi, the repeat-rich regions may be subjected to a process termed repeat-induced point mutation (RIP). Both repeat activity and RIP are thought to play a significant role in evolution of secreted virulence proteins, termed effectors. We present a complete genome sequence of S. sclerotiorum generated using Single Molecule Real-Time Sequencing technology with highly accurate annotations produced using an extensive RNA sequencing data set. We identified 70 effector candidates and have highlighted their in planta expression profiles. Furthermore, we characterized the genome architecture of S. sclerotiorum in comparison to plant pathogens that exhibit “two-speed” genomes. We show that there is a significant association between positions of secreted proteins and regions with a high RIP index in S. sclerotiorum but we did not detect a correlation between secreted protein proportion and GC content. Neither did we detect a negative correlation between CDS content and secreted protein proportion across the S. sclerotiorum genome. We conclude that S. sclerotiorum exhibits subtle signatures of enhanced mutation of secreted proteins in specific genomic compartments as a result of transposition and RIP activity. However, these signatures are not observable at the whole-genome scale.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Lyme : collectionnons les tiques pour aider les chercheurs !

Lyme : collectionnons les tiques pour aider les chercheurs ! | MycorWeb Plant-Microbe Interactions | Scoop.it
Pour mieux lutter contre la maladie de Lyme, les chercheurs font appel aux citoyens. Chacun est invité, dès cet été, à signaler le lieu où il a été piqué par une tique et à la leur envoyer.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

The ancestral levels of transcription and the evolution of sexual phenotypes in filamentous fungi

The ancestral levels of transcription and the evolution of sexual phenotypes in filamentous fungi | MycorWeb Plant-Microbe Interactions | Scoop.it
Author summary Scientists are just beginning to be able to link comparative developmental biology—which focuses on phenotypes—to comparative genetics (including comparative genomics and transcriptomics). The challenge to doing so has been to coordinate genetic analysis in multiple species, each with distinct genomes, in order to reveal fundamental knowledge of how the modules underlying development evolve and change. In this research, we have brought comparative genetics, developmental biology, genomics, and transcriptomics into a single phylogenetic framework. By using comparative genomic data to identify orthologous genes, comparative transcriptomic data to reconstruct evolutionary changes of gene expression phenotypes across multiple species, and gene knockout technology in more than one species to interrogate function, we have identified a powerful technique to reveal genes whose evolving role has led to developmental and phenotypic differences among species.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

De Novo Whole-Genome Sequencing of the Wood Rot Fungus Polyporus brumalis, Which Exhibits Potential Terpenoid Metabolism

Polyporus brumalis is able to synthesize several sesquiterpenes during fungal growth. Using a single-molecule real-time sequencing platform, we present the 53-Mb draft genome of P. brumalis, which contains 6,231 protein-coding genes. Gene annotation and isolation support genetic information, which can increase the understanding of sesquiterpene metabolism in P. brumalis.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Fungi associated with mesophotic macroalgae from the ‘Au‘au Channel, west Maui are differentiated by host and overlap terrestrial communities

Fungi associated with mesophotic macroalgae from the ‘Au‘au Channel, west Maui are differentiated by host and overlap terrestrial communities | MycorWeb Plant-Microbe Interactions | Scoop.it
Mesophotic coral ecosystems are an almost entirely unexplored and undocumented environment that likely contains vast reservoirs of undescribed biodiversity. Twenty-four macroalgae samples, representing four genera, were collected from a Hawaiian mesophotic reef at water depths between 65 and 86 m in the ‘Au‘au Channel, Maui, Hawai‘i. Algal tissues were surveyed for the presence and diversity of fungi by sequencing the ITS1 gene using Illumina technology. Fungi from these algae were then compared to previous fungal surveys conducted in Hawaiian terrestrial ecosystems. Twenty-seven percent of the OTUs present on the mesophotic coral ecosystem samples were shared between the marine and terrestrial environment. Subsequent analyses indicated that host species of algae significantly differentiate fungal community composition. This work demonstrates yet another understudied habitat with a moderate diversity of fungi that should be considered when estimating global fungal diversity.
more...
No comment yet.
Rescooped by Francis Martin from Host:microbe Interactions
Scoop.it!

Arabidopsis JASMONATE-INDUCED OXYGENASES down-regulate plant immunity by hydroxylation and inactivation of the hormone jasmonic acid

Arabidopsis JASMONATE-INDUCED OXYGENASES down-regulate plant immunity by hydroxylation and inactivation of the hormone jasmonic acid | MycorWeb Plant-Microbe Interactions | Scoop.it

In plants the hormone jasmonic acid (JA) is synthesized in response to attack by pathogens and herbivores, leading to activation of defense responses. Rapidly following JA accumulation the hormone is metabolized, presumably to prevent inhibitive effects of high JA levels on growth and development. The enzymes that directly inactivate JA were so far unknown. Here, we identify four jasmonate-induced oxygenases (JOXs) in Arabidopsis that hydroxylate jasmonic acid to form inactive 12-OH-JA. A mutant that no longer produces the four enzymes hyperaccumulates JA, exhibits reduced growth, and is highly resistant to attackers that are sensitive to JA-dependent defense. The JOX enzymes thus play an important role in determining the amplitude and duration of JA responses to balance the growth–defense trade-off.


Via Jonathan Plett
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Epigenetic regulation of development and pathogenesis in fungal plant pathogens

Epigenetic regulation of development and pathogenesis in fungal plant pathogens | MycorWeb Plant-Microbe Interactions | Scoop.it
Evidently, epigenetics is at forefront in explaining the mechanisms underlying the success of human pathogens and in the identification of pathogen-induced modifications within host plants. However, there is a lack of studies highlighting the role of epigenetics in the modulation of the growth and pathogenicity of fungal plant pathogens. In this review, we attempt to highlight and discuss the role of epigenetics in the regulation of the growth and pathogenicity of fungal phytopathogens using Magnaporthe oryzae, a devastating fungal plant pathogen, as a model system. With the perspective of wide application in the understanding of the development, pathogenesis and control of other fungal pathogens, we attempt to provide a synthesized view of the epigenetic studies conducted on M. oryzae to date. First, we discuss the mechanisms of epigenetic modifications in M. oryzae and their impact on fungal development and pathogenicity. Second, we highlight the unexplored epigenetic mechanisms and areas of research that should be considered in the near future to construct a holistic view of epigenetic functioning in M. oryzae and other fungal plant pathogens. Importantly, the development of a complete understanding of the modulation of epigenetic regulation in fungal pathogens can help in the identification of target points to combat fungal pathogenesis
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Population genomics of picophytoplankton unveils novel chromosome hypervariability

Population genomics of picophytoplankton unveils novel chromosome hypervariability | MycorWeb Plant-Microbe Interactions | Scoop.it
Tiny photosynthetic microorganisms that form the picoplankton (between 0.3 and 3 μm in diameter) are at the base of the food web in many marine ecosystems, and their adaptability to environmental change hinges on standing genetic variation. Although the genomic and phenotypic diversity of the bacterial component of the oceans has been intensively studied, little is known about the genomic and phenotypic diversity within each of the diverse eukaryotic species present. We report the level of genomic diversity in a natural population of Ostreococcus tauri (Chlorophyta, Mamiellophyceae), the smallest photosynthetic eukaryote. Contrary to the expectations of clonal evolution or cryptic species, the spectrum of genomic polymorphism observed suggests a large panmictic population (an effective population size of 1.2 × 107) with pervasive evidence of sexual reproduction. De novo assemblies of low-coverage chromosomes reveal two large candidate mating-type loci with suppressed recombination, whose origin may pre-date the speciation events in the class Mamiellophyceae. This high genetic diversity is associated with large phenotypic differences between strains. Strikingly, resistance of isolates to large double-stranded DNA viruses, which abound in their natural environment, is positively correlated with the size of a single hypervariable chromosome, which contains 44 to 156 kb of strain-specific sequences. Our findings highlight the role of viruses in shaping genome diversity in marine picoeukaryotes.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

New technologies boost genome quality

New technologies boost genome quality | MycorWeb Plant-Microbe Interactions | Scoop.it
Three years ago, Erich Jarvis helped mastermind a massive DNA sequencing effort that netted genomes for more than 40 bird species and produced a better avian family tree. But when he tried to compare the avian genomes to those of other species to learn about the evolution and function of several key brain genes, he was stymied. His team found that gene sequences from most of the comparison species—even humans—were incomplete, missing, or misplaced in the larger genome. The group had to resequence sections of several genomes to get the needed data, delaying their project many months.

“The genome quality makes a huge difference in the type of science we can do,” says Jarvis, a neuroscientist at The Rockefeller University in New York City. So he and many other genomics experts are launching a quiet revolution aimed at building better genomes, one made possible by newer sequencing technologies, novel methods for locating sequences on chromosomes, and improved software for piecing DNA together. In the past 6 months, these approaches have led to a flood of high-quality animal and plant genomes in preprints and published papers.
more...
No comment yet.
Scooped by Francis Martin
Scoop.it!

Evolution of the wheat blast fungus through functional losses in a host specificity determinant

Evolution of the wheat blast fungus through functional losses in a host specificity determinant | MycorWeb Plant-Microbe Interactions | Scoop.it

In the 1980s, wheat crops began to fall to the fungal pathogen that causes blast disease. First seen in Brazil, wheat blast last year caused devastating crop losses in Bangladesh. Inoue et al. tracked down the shifting genetics that have allowed the emergence of this potentially global threat to wheat crops (see the Perspective by Maekawa and Schulze-Lefert). Wheat varieties with a disabled resistance gene were susceptible to pathogen strains that affected oat and ryegrass crops. Subsequent genetic changes in the pathogen amped up the virulence in wheat.

more...
No comment yet.