| multigene phylogenies of ophiostoma clavigerum and closely related species from bark beetle-attacked pinus in north america. | leptographium pyrinum, leptographium terebrantis, ophiostoma aureum, ophiostoma clavigerum, and ophiostoma robustum are very similar in morphology, host trees choice, and the way they are disseminated by bark beetles. their phylogenetic relationships were clarified using rdna and protein coding genes including actin, beta-tubulin, and translation elongation factor-1alpha. protein coding gene trees showed better resolution than the rdna tree, which generated three clades: o. clavigerum, l. terebr ... | 2004 | 15268942 |
| leptographium longiclavatum sp. nov., a new species associated with the mountain pine beetle, dendroctonus ponderosae. | the mountain pine beetle, dendroctonus ponderosae, and its fungal associates are devastating the lodgepole pine forests in british columbia, canada. during our fungal survey, an unknown leptographium species has been consistently isolated from both d. ponderosae and infested lodgepole pine (pinus contorta var. latifolia). this leptographium species has similar morphology with the leptographium anamorph of ophiostoma clavigerum whose association with the d. ponderosae is well known. however, thor ... | 2005 | 16279410 |
| temperature determines symbiont abundance in a multipartite bark beetle-fungus ectosymbiosis. | in this study, we report evidence that temperature plays a key role in determining the relative abundance of two mutualistic fungi associated with an economically and ecologically important bark beetle, dendroctonus ponderosae. the symbiotic fungi possess different optimal temperature ranges. these differences determine which fungus is vectored by dispersing host beetles as temperatures fluctuate over a season. grosmannia clavigera is the predominant fungus carried by dispersing beetles during c ... | 2007 | 17264992 |
| generation and annotation of lodgepole pine and oleoresin-induced expressed sequences from the blue-stain fungus ophiostoma clavigerum, a mountain pine beetle-associated pathogen. | ophiostoma clavigerum is a destructive pathogen of lodgepole pine (pinus contorta) forests in western north america. it is therefore a relevant system for a genomics analysis of fungi vectored by bark beetles. to begin characterizing molecular interactions between the pathogen and its conifer host, we created an expressed sequence tag (est) collection for o. clavigerum. lodgepole pine sawdust and oleoresin media were selected to stimulate gene expression that would be specific to this host inter ... | 2007 | 17328114 |
| temporal variation in mycophagy and prevalence of fungi associated with developmental stages of dendroctonus ponderosae (coleoptera: curculionidae). | mycophagy by bark beetles is widespread. however, little is known regarding which developmental stages of bark beetles actually feed on fungi. to study this question, we sampled fungi associated with dendroctonus ponderosae hopkins (coleoptera: curculionidae) throughout development in naturally attacked trees. isolations of fungi were made from phloem adjacent to brood and from brood exoskeletons and guts. overall, the incidence of fungi with individual brood increased as brood development progr ... | 2007 | 17349118 |
| dietary benefits of fungal associates to an eruptive herbivore: potential implications of multiple associates on host population dynamics. | we used the mountain pine beetle (dendroctonus ponderosae hopkins) and its two fungal associates, grosmannia clavigera and ophiostoma montium, to study potential nutritional benefits of fungi to bark beetles. we tested for potential effects of feeding on phloem colonized by fungi on beetle performance in field and laboratory studies. the fungi increased nitrogen levels in the phloem of attacked trees by 40%, indicating that it may be an important source of dietary nitrogen for mountain pine beet ... | 2007 | 18284766 |
| in vitro interactions between yeasts and bacteria and the fungal symbionts of the mountain pine beetle (dendroctonus ponderosae). | multi-trophic interactions between prokaryotes, unicellular eukaryotes, and ecologically intertwined metazoans are presumably common in nature, yet rarely described. the mountain pine beetle, dendroctonus ponderosae, is associated with two filamentous fungi, grosmannia clavigera and ophiostoma montium. other microbes, including yeasts and bacteria, are also present in the phloem, but it is not known whether they interact with the symbiotic fungi or the host beetle. to test whether such interacti ... | 2008 | 18322728 |
| competition and coexistence in a multi-partner mutualism: interactions between two fungal symbionts of the mountain pine beetle in beetle-attacked trees. | despite overlap in niches, two fungal symbionts of the mountain pine beetle (dendroctonus ponderosae), grosmannia clavigera and ophiostoma montium, appear to coexist with one another and their bark beetle host in the phloem of trees. we sampled the percent of phloem colonized by fungi four times over 1 year to investigate the nature of the interaction between these two fungi and to determine how changing conditions in the tree (e.g., moisture) affect the interaction. both fungi colonized phloem ... | 2009 | 18545867 |
| effects of water potential and solute on the growth and interactions of two fungal symbionts of the mountain pine beetle. | we investigated the effect of water potential (wp) on the growth of, and interaction between, two ophiostomatoid fungi, grosmannia clavigera and ophiostoma montium, associated with the mountain pine beetle (dendroctonus ponderosae). the wp of malt extract agar was amended by adding potassium chloride (kcl) or sucrose. growth of both fungi decreased with wp on kcl-amended media. growth of g. clavigera also decreased with wp on sucrose-amended media, although growth was stimulated on these media c ... | 2009 | 18640273 |
| genetic diversity and the presence of two distinct groups in ophiostoma clavigerum associated with dendroctonus ponderosae in british columbia and the northern rocky mountains. | abstract the sapstaining fungal pathogen ophiostoma clavigerum is associated with the mountain pine beetle (dendroctonus ponderosae), which is currently the most destructive forest pest in north america. the genetic diversity of o. clavigerum populations collected from five sites in canada and two sites in the united states was estimated with amplified fragment length polymorphism (aflp) analysis. genomic dna from 170 o. clavigerum isolates was digested with ecori and psti and amplified with six ... | 2007 | 18944182 |
| de novo genome sequence assembly of a filamentous fungus using sanger, 454 and illumina sequence data. | sequencing-by-synthesis technologies can reduce the cost of generating de novo genome assemblies. we report a method for assembling draft genome sequences of eukaryotic organisms that integrates sequence information from different sources, and demonstrate its effectiveness by assembling an approximately 32.5 mb draft genome sequence for the forest pathogen grosmannia clavigera, an ascomycete fungus. we also developed a method for assessing draft assemblies using illumina paired end read data and ... | 2009 | 19747388 |
| agrobacterium-meditated gene disruption using split-marker in grosmannia clavigera, a mountain pine beetle associated pathogen. | grosmannia clavigera is a fungal pathogen associated with the mountain pine beetle (dendroctonus ponderosae) which is devastating large areas of western canada's conifer forests. this fungus also produces a dark melanin pigment that discolors pine sapwood. we have generated the draft genome of g. clavigera. however, functional characterization of genes identified in the genome sequence requires an efficient gene disruption method. in this work, we report a gene replacement strategy for g. clavig ... | 2010 | 20229292 |
| nitrogen concentration in mountain pine beetle larvae reflects nitrogen status of the tree host and two fungal associates. | individual lodgepole pines (pinus contorta) were fertilized with urea at nitrogen (n) inputs equivalent to 0, 315, or 630 kg/ha. four months after application of the fertilizer, inner bark tissue n concentrations were significantly higher in the trees that had received the low dose (315 kg/ha) fertilization treatment than in the control trees; trees that had received the high-dose treatment (630 kg/ha) were intermediate and not significantly different from either of the other treatments. there w ... | 2010 | 20550794 |
| rapid identification and detection of pine pathogenic fungi associated with mountain pine beetles by padlock probes. | fifteen million hectares of pine forests in western canada have been attacked by the mountain pine beetle (dendroctonus ponderosae; mpb), leading to devastating economic losses. grosmannia clavigera and leptographium longiclavatum, are two fungi intimately associated with the beetles, and are crucial components of the epidemic. to detect and discriminate these two closely related pathogens, we utilized a method based on ligase-mediated nucleotide discrimination with padlock probe technology, and ... | 2010 | 20650291 |
| gene discovery for the bark beetle-vectored fungal tree pathogen grosmannia clavigera. | grosmannia clavigera is a bark beetle-vectored fungal pathogen of pines that causes wood discoloration and may kill trees by disrupting nutrient and water transport. trees respond to attacks from beetles and associated fungi by releasing terpenoid and phenolic defense compounds. it is unclear which genes are important for g. clavigera's ability to overcome antifungal pine terpenoids and phenolics. | 2010 | 20920358 |
| target-specific pcr primers can detect and differentiate ophiostomatoid fungi from microbial communities associated with the mountain pine beetle dendroctonus ponderosae. | the aim of this study was to develop dna probes that could identify the major fungal species associated with mountain pine beetles (mpb). the beetles are closely associated with fungal species that include ophiostomatoid fungi that can be difficult to differentiate morphologically. the most frequently isolated associates are the pine pathogens grosmannia clavigera and leptographium longiclavatum, the less pathogenic ophiostoma montium, and an undescribed ceratocystiopsis species (cop. sp.). beca ... | 2010 | 20943192 |
| genetic relationships among leptographium terebrantis and the mycangial fungi of three western dendroctonus bark beetles. | morphology, mitochondrial dna (mtdna) restriction fragment polymorphisms (rflps) and nuclear dna (ndna) fingerprinting were used to clarify relationships among the morphologically similar ophiostoma and leptographium species associated with mycangia of three dendroctonus bark beetles (ophiostoma clavigerum associated with both d. ponderosae and d. jeffreyi, and l. pyrinum associated with d. adjunctus), as well as a closely related nonmycangial bark beetle associate (l. terebrantis). most isolate ... | 2003 | 21148985 |
| genome and transcriptome analyses of the mountain pine beetle-fungal symbiont grosmannia clavigera, a lodgepole pine pathogen. | in western north america, the current outbreak of the mountain pine beetle (mpb) and its microbial associates has destroyed wide areas of lodgepole pine forest, including more than 16 million hectares in british columbia. grosmannia clavigera (gc), a critical component of the outbreak, is a symbiont of the mpb and a pathogen of pine trees. to better understand the interactions between gc, mpb, and lodgepole pine hosts, we sequenced the ~30-mb gc genome and assembled it into 18 supercontigs. we p ... | 2011 | 21262841 |
| limited response of ponderosa pine bole defenses to wounding and fungi. | tree defense against bark beetles (curculionidae: scolytinae) and their associated fungi generally comprises some combination of constitutive (primary) and induced (secondary) defenses. in pines, the primary constitutive defense against bark beetles consists of preformed resin stored in resin ducts. induced defenses at the wound site (point of beetle entry) in pines may consist of an increase in resin flow and necrotic lesion formation. the quantity and quality of both induced and constitutive d ... | 2011 | 21551357 |
| fungal associates of the lodgepole pine beetle, dendroctonus murrayanae. | bark beetles are well known vectors of ophiostomatoid fungi including species of ophiostoma, grosmannia and ceratocystis. in this study, the most common ophiostomatoid fungi associated with the lodgepole pine beetle, dendroctonus murrayanae, were characterized. pre-emergent and post-attack adult beetles were collected from lodgepole pines at four sites in british columbia, canada. fungi were isolated from these beetles and identified using a combination of morphology and dna sequence comparisons ... | 2011 | 21553309 |
| gene genealogies reveal cryptic species and host preferences for the pine fungal pathogen grosmannia clavigera. | grosmannia clavigera is a fungal pathogen of pine forests in western north america and a symbiotic associate of two sister bark beetles: dendroctonus ponderosae and d. jeffreyi. this fungus and its beetle associate d. ponderosae are expanding in large epidemics in western north america. using the fungal genome sequence and gene annotations, we assessed whether fungal isolates from the two beetles inhabiting different species of pine in epidemic regions of western canada and the usa, as well as i ... | 2011 | 21557782 |
| characterization of microsatellite loci in the fungus, grosmannia clavigera, a pine pathogen associated with the mountain pine beetle. | the largest forest pest epidemic in canadian history caused by the mountain pine beetle (mpb) and its fungal associates has killed over 15 million hectares of forest. sixty simple sequence repeat regions were identified from grosmannia clavigera, an mpb associated fungus. eight loci genotyped in 53 isolates from two populations in british columbia, canada revealed three to 10 alleles per locus and gene diversities of 0 to 0.79. all but two of these loci showed length polymorphism in leptographiu ... | 2009 | 21564944 |
| a biologist's guide to de novo genome assembly using next-generation sequence data: a test with fungal genomes. | we offer a guide to de novo genome assembly(1) using sequence data generated by the illumina platform for biologists working with fungi or other organisms whose genomes are less than 100mb in size. the guide requires no familiarity with sequencing assembly technology or associated computer programs. it defines commonly used terms in genome sequencing and assembly; provides examples of assembling short-read genome sequence data for four strains of the fungus grosmannia clavigera using four assemb ... | 2011 | 21749903 |
| antifungal activity of a pinus monticola antimicrobial peptide 1 (pm-amp1) and its accumulation in western white pine infected with cronartium ribicola. | pinus monticola antimicrobial peptide 1 (pm-amp1) was expressed and purified from bacterial cell lysate and its identity and purity confirmed by western blot analysis using the pm-amp1 antibody. application of pm-amp1 resulted in visible hyphal growth inhibition of cronartium ribicola , phellinus sulphurascens , ophiostoma montium , and ophiostoma clavigerum 3-12 days post-treatment. pm-amp1 also inhibited spore germination of several other phytopathogenic fungi by 32%-84% 5-ádays post-treatment ... | 2011 | 21823970 |
| genetic variation of lodgepole pine, pinus contorta var. latifolia, chemical and physical defenses that affect mountain pine beetle, dendroctonus ponderosae, attack and tree mortality. | plant secondary chemistry is determined by both genetic and environmental factors, and while large intraspecific variation in secondary chemistry has been reported frequently, the levels of genetic variation of many secondary metabolites in forest trees in the context of potential resistance against pests have been rarely investigated. we examined the effect of tree genotype and environment/site on the variation in defensive secondary chemistry of lodgepole pine, pinus contorta var. latifolia, a ... | 2011 | 21845434 |
| Effect of water stress and fungal inoculation on monoterpene emission from an historical and a new pine host of the mountain pine beetle. | The mountain pine beetle (Dendroctonus ponderosae, MPB) has killed millions of lodgepole pine (Pinus contorta) trees in Western Canada, and recent range expansion has resulted in attack of jack pine (Pinus banksiana) in Alberta. Establishment of MPB in the Boreal forest will require use of jack pine under a suite of environmental conditions different from those it typically encounters in its native range. Lodgepole and jack pine seedlings were grown under controlled environment conditions and su ... | 2011 | 21874397 |
| Population structure and migration pattern of a conifer pathogen, Grosmannia clavigera, as influenced by its symbiont, the mountain pine beetle. | We investigated the population structure of Grosmannia clavigera (Gc), a fungal symbiont of the mountain pine beetle (MPB) that plays a crucial role in the establishment and reproductive success of this pathogen. This insect-fungal complex has destroyed over 16 million ha of lodgepole pine forests in Canada, the largest MPB epidemic in recorded history. During this current epidemic, MPB has expanded its range beyond historically recorded boundaries, both northward and eastward, and has now reach ... | 2012 | 22118059 |
| cloning and characterization of chitinases from interior spruce and lodgepole pine. | chitinases have been implicated in the defence of conifers against insects and pathogens. cdna for six chitinases were cloned from interior spruce (picea glauca x engelmannii) and four from lodgepole pine (pinus contorta). the cloned interior spruce chitinases were annotated class i pgechia1-1 and pgechia1-2, class ii pgechia2-1, class iv pgechia4-1, and class vii pgechia7-1 and pgechia7-2; lodgepole pine chitinases were annotated class i pcchia1-1, class iv pcchia4-1, and class vii pcchia7-1 an ... | 2014 | 24564978 |
| genetic and genomic evidence of niche partitioning and adaptive radiation in mountain pine beetle fungal symbionts. | bark beetles form multipartite symbiotic associations with blue stain fungi (ophiostomatales, ascomycota). these fungal symbionts play an important role during the beetle's life cycle by providing nutritional supplementation, overcoming tree defences and modifying host tissues to favour brood development. the maintenance of stable multipartite symbioses with seemingly less competitive symbionts in similar habitats is of fundamental interest to ecology and evolution. we tested the hypothesis that ... | 2017 | 28231417 |
| a genomic comparison of putative pathogenicity-related gene families in five members of the ophiostomatales with different lifestyles. | ophiostomatoid fungi are vectored by their bark-beetle associates and colonize different host tree species. to survive and proliferate in the host, they have evolved mechanisms for detoxification and elimination of host defence compounds, efficient nutrient sequestration, and, in pathogenic species, virulence towards plants. here, we assembled a draft genome of the spruce pathogen ophiostoma bicolor. for our comparative and phylogenetic analyses, we mined the genomes of closely related species ( ... | 2017 | 28215351 |
| water-deficit and fungal infection can differentially affect the production of different classes of defense compounds in two host pines of mountain pine beetle. | bark beetles are important agents of tree mortality in conifer forests and their interaction with trees is influenced by host defense chemicals, such as monoterpenes and phenolics. since mountain pine beetle (dendroctonus ponderosae hopkins) has expanded its host range from lodgepole pine (pinus contorta doug. ex loud. (var. latifolia engelm.))-dominated forests to the novel jack pine (pinus banksiana lamb.) forests in western canada, studies investigating the jack pine suitability as a host for ... | 2016 | 27881799 |
| fatty acid composition of novel host jack pine do not prevent host acceptance and colonization by the invasive mountain pine beetle and its symbiotic fungus. | fatty acids are major components of plant lipids and can affect growth and development of insect herbivores. despite a large literature examining the roles of fatty acids in conifers, relatively few studies have tested the effects of fatty acids on insect herbivores and their microbial symbionts. particularly, whether fatty acids can affect the suitability of conifers for insect herbivores has never been studied before. thus, we evaluated if composition of fatty acids impede or facilitate coloni ... | 2016 | 27583820 |
| fungal volatiles can act as carbon sources and semiochemicals to mediate interspecific interactions among bark beetle-associated fungal symbionts. | mountain pine beetle (dendroctonus ponderosae) has killed millions of hectares of pine forests in western north america. beetle success is dependent upon a community of symbiotic fungi comprised of grosmannia clavigera, ophiostoma montium, and leptographium longiclavatum. factors regulating the dynamics of this community during pine infection are largely unknown. however, fungal volatile organic compounds (fvocs) help shape fungal interactions in model and agricultural systems and thus may be im ... | 2016 | 27583519 |
| rapid induction of multiple terpenoid groups by ponderosa pine in response to bark beetle-associated fungi. | ponderosa pine (pinus ponderosa) is a major and widely distributed component of conifer biomes in western north america and provides substantial ecological and economic benefits. this tree is exposed to several tree-killing bark beetle-microbial complexes, including the mountain pine beetle (dendroctonus ponderosae) and the phytopathogenic fungus grosmannia clavigera that it vectors, which are among the most important. induced responses play a crucial role in conifer defenses, yet these have not ... | 2016 | 26662358 |
| differences in defence responses of pinus contorta and pinus banksiana to the mountain pine beetle fungal associate grosmannia clavigera are affected by water deficit. | we tested the hypotheses that responses to the mountain pine beetle fungal associate grosmannia clavigera will differ between the evolutionarily co-evolved host lodgepole pine (pinus contorta var. latifolia) and the naïve host jack pine (pinus banksiana) and that these responses will be influenced by water availability. g. clavigera inoculation resulted in more rapid stem lesion development in lodgepole than in jack pine; water deficit delayed lesion development in both species. decreased hydrau ... | 2016 | 26205849 |
| bacteria influence mountain pine beetle brood development through interactions with symbiotic and antagonistic fungi: implications for climate-driven host range expansion. | bark beetles are associated with diverse communities of symbionts. although fungi have received significant attention, we know little about how bacteria, and in particular their interactions with fungi, affect bark beetle reproduction. we tested how interactions between four bacterial associates, two symbiotic fungi, and two opportunistic fungi affect performance of mountain pine beetles (dendroctonus ponderosae) in host tissue. we compared beetle performance in phloem of its historical host, lo ... | 2015 | 26037523 |
| the cyp51f1 gene of leptographium qinlingensis: sequence characteristic, phylogeny and transcript levels. | leptographium qinlingensis is a fungal associate of the chinese white pine beetle (dendroctonus armandi) and a pathogen of the chinese white pine (pinus armandi) that must overcome the terpenoid oleoresin defenses of host trees. l. qinlingensis responds to monoterpene flow with abundant mechanisms that include export and the use of these compounds as a carbon source. as one of the fungal cytochrome p450 proteins (cyps), which play important roles in general metabolism, cyp51 (lanosterol 14-α dem ... | 2015 | 26016505 |
| oleic acid metabolism via a conserved cytochrome p450 system-mediated ω-hydroxylation in the bark beetle-associated fungus grosmannia clavigera. | the bark beetle-associated fungus grosmannia clavigera participates in the large-scale destruction of pine forests. in the tree, it must tolerate saturating levels of toxic conifer defense chemicals (e.g. monoterpenes). the fungus can metabolize some of these compounds through the ß-oxidation pathway and use them as a source of carbon. it also uses carbon from pine triglycerides, where oleic acid is the most common fatty acid. high levels of free fatty acids, however, are toxic and can cause add ... | 2015 | 25794012 |
| effects of temperature on growth, sporulation, and competition of mountain pine beetle fungal symbionts. | the mountain pine beetle, dendroctonus ponderosae, depends on two fungi, grosmannia clavigera and ophiostoma montium, to augment a nutrient-poor woody food resource. because the two fungi exert differential effects on the host beetle, temperature-driven differences in fungal growth and competition outcomes have a strong potential to influence host population dynamics. weisolated fungi from beetles and wood from three locations in montana and utah, usa, and measured their growth rates and sporula ... | 2015 | 25773718 |
| integrating models to investigate critical phenological overlaps in complex ecological interactions: the mountain pine beetle-fungus symbiosis. | the fates of individual species are often tied to synchronization of phenology, however, few methods have been developed for integrating phenological models involving linked species. in this paper, we focus on mountain pine beetle (mpb, dendroctonus ponderosae) and its two obligate mutualistic fungi, grosmannia clavigera and ophiostoma montium. growth rates of all three partners are driven by temperature, and their idiosyncratic responses affect interactions at important life stage junctures. on ... | 2015 | 25556687 |
| functional annotation of the ophiostoma novo-ulmi genome: insights into the phytopathogenicity of the fungal agent of dutch elm disease. | the ascomycete fungus ophiostoma novo-ulmi is responsible for the pandemic of dutch elm disease that has been ravaging europe and north america for 50 years. we proceeded to annotate the genome of the o. novo-ulmi strain h327 that was sequenced in 2012. the 31.784-mb nuclear genome (50.1% gc) is organized into 8 chromosomes containing a total of 8,640 protein-coding genes that we validated with rna sequencing analysis. approximately 53% of these genes have their closest match to grosmannia clavi ... | 2014 | 25539722 |
| population structure of mountain pine beetle symbiont leptographium longiclavatum and the implication on the multipartite beetle-fungi relationships. | over 18 million ha of forests have been destroyed in the past decade in canada by the mountain pine beetle (mpb) and its fungal symbionts. understanding their population dynamics is critical to improving modeling of beetle epidemics and providing potential clues to predict population expansion. leptographium longiclavatum and grosmannia clavigera are fungal symbionts of mpb that aid the beetle to colonize and kill their pine hosts. we investigated the genetic structure and demographic expansion ... | 2014 | 25153489 |
| gene discovery for enzymes involved in limonene modification or utilization by the mountain pine beetle-associated pathogen grosmannia clavigera. | to successfully colonize and eventually kill pine trees, grosmannia clavigera (gs cryptic species), the main fungal pathogen associated with the mountain pine beetle (dendroctonus ponderosae), has developed multiple mechanisms to overcome host tree chemical defenses, of which terpenoids are a major component. in addition to a monoterpene efflux system mediated by a recently discovered abc transporter, gs has genes that are highly induced by monoterpenes and that encode enzymes that modify or uti ... | 2014 | 24837377 |
| comparative genomics of the pine pathogens and beetle symbionts in the genus grosmannia. | studies on beetle/tree fungal symbionts typically characterize the ecological and geographic distributions of the fungal populations. there is limited understanding of the genome-wide evolutionary processes that act within and between species as such fungi adapt to different environments, leading to physiological differences and reproductive isolation. here, we assess genomic evidence for such evolutionary processes by extending our recent work on grosmannia clavigera, which is vectored by the m ... | 2014 | 24627033 |
| influence of water deficit on the molecular responses of pinus contorta × pinus banksiana mature trees to infection by the mountain pine beetle fungal associate, grosmannia clavigera. | conifers exhibit a number of constitutive and induced mechanisms to defend against attack by pests and pathogens such as mountain pine beetle (dendroctonus ponderosae hopkins) and their fungal associates. ecological studies have demonstrated that stressed trees are more susceptible to attack by mountain pine beetle than their healthy counterparts. in this study, we tested the hypothesis that water deficit affects constitutive and induced responses of mature lodgepole pine × jack pine hybrids (pi ... | 2014 | 24319029 |
| single-nucleotide polymorphism discovery in leptographium longiclavatum, a mountain pine beetle-associated symbiotic fungus, using whole-genome resequencing. | single-nucleotide polymorphisms (snps) are rapidly becoming the standard markers in population genomics studies; however, their use in nonmodel organisms is limited due to the lack of cost-effective approaches to uncover genome-wide variation, and the large number of individuals needed in the screening process to reduce ascertainment bias. to discover snps for population genomics studies in the fungal symbionts of the mountain pine beetle (mpb), we developed a road map to discover snps and to pr ... | 2014 | 24152017 |
| bacteria associated with a tree-killing insect reduce concentrations of plant defense compounds. | bark beetles encounter a diverse array of constitutive and rapidly induced terpenes when attempting to colonize living conifers. concentrations of these compounds at entry sites can rapidly reach levels toxic to beetles, their brood, and fungal symbionts. large numbers of beetles can overwhelm tree defenses via pheromone-mediated mass attacks, but the mechanisms are poorly understood. we show that bacteria associated with mountain pine beetles can metabolize monoterpenes and diterpene acids. the ... | 2013 | 23807433 |
| the role of temperature variability in stabilizing the mountain pine beetle-fungus mutualism. | as global climate patterns continue to change and extreme weather events become increasingly common, it is likely that many ecological interactions will be affected. one such interaction is the multipartite symbiosis that exists between the mountain pine beetle and two species of fungi, grosmannia clavigera and ophiostoma montium. in this mutualism, the fungi provide nutrition to the beetle, while the fungi benefit by being dispersed to new host trees. multi-partite mutualisms are predicted to b ... | 2013 | 23791850 |
| the genome and transcriptome of the pine saprophyte ophiostoma piceae, and a comparison with the bark beetle-associated pine pathogen grosmannia clavigera. | ophiostoma piceae is a wood-staining fungus that grows in the sapwood of conifer logs and lumber. we sequenced its genome and analyzed its transcriptomes under a range of growth conditions. a comparison with the genome and transcriptomes of the mountain pine beetle-associated pathogen grosmannia clavigera highlights differences between a pathogen that colonizes and kills living pine trees and a saprophyte that colonizes wood and the inner bark of dead trees. | 2013 | 23725015 |
| unequal recombination and evolution of the mating-type (mat) loci in the pathogenic fungus grosmannia clavigera and relatives. | sexual reproduction in fungi is regulated by the mating-type (mat) locus where recombination is suppressed. we investigated the evolution of mat loci in eight fungal species belonging to grosmannia and ophiostoma (sordariomycetes, ascomycota) that include conifer pathogens and beetle symbionts. the mat1-2 idiomorph/allele was identified from the assembled and annotated grosmannia clavigera genome, and the mat locus is flanked by genes coding for cytoskeleton protein (sla) and dna lyase. the synt ... | 2013 | 23450093 |
| a specialized abc efflux transporter gcabc-g1 confers monoterpene resistance to grosmannia clavigera, a bark beetle-associated fungal pathogen of pine trees. | grosmannia clavigera is a bark beetle-vectored pine pathogen in the mountain pine beetle epidemic in western north america. grosmannia clavigera colonizes pines despite the trees' massive oleoresin terpenoid defences. we are using a functional genomics approach to identify g. clavigera's mechanisms of adaptation to pine defences. we annotated the abc transporters in the g. clavigera genome and generated rna-seq transcriptomes from g. clavigera grown with a range of terpenes. we functionally char ... | 2013 | 23252416 |
| the cytochromes p450 of grosmannia clavigera: genome organization, phylogeny, and expression in response to pine host chemicals. | grosmannia clavigera is a fungal associate of the mountain pine beetle (dendroctonus ponderosae) and a pathogen of lodgepole pine (pinus contorta) that must overcome terpenoid oleoresin and phenolic defenses of host trees. g. clavigera responds to monoterpene influx with complementary mechanisms that include export and the use of these compounds as a carbon source. cytochromes p450 (cyps) may also be involved in the metabolism of host defense compounds. we have identified and phylogenetically cl ... | 2013 | 23111002 |
| the relative abundance of mountain pine beetle fungal associates through the beetle life cycle in pine trees. | the mountain pine beetle (mpb) is a native bark beetle of western north america that attacks pine tree species, particularly lodgepole pine. it is closely associated with the ophiostomatoid ascomycetes grosmannia clavigera, leptographium longiclavatum, ophiostoma montium, and ceratocystiopsis sp.1, with which it is symbiotically associated. to develop a better understanding of interactions between beetles, fungi, and host trees, we used target-specific dna primers with qpcr to assess the changes ... | 2012 | 22735936 |
| the impact of phloem nutrients on overwintering mountain pine beetles and their fungal symbionts. | in the low nutrient environment of conifer bark, subcortical beetles often carry symbiotic fungi that concentrate nutrients in host tissues. although bark beetles are known to benefit from these symbioses, whether this is because they survive better in nutrient-rich phloem is unknown. after manipulating phloem nutrition by fertilizing lodgepole pine trees (pinus contorta douglas var. latifolia), we found bolts from fertilized trees to contain more living individuals, and especially more pupae an ... | 2012 | 22732605 |
| differential effects of plant ontogeny and damage type on phloem and foliage monoterpenes in jack pine (pinus banksiana). | coniferous trees have both constitutive and inducible defences that deter or kill herbivores and pathogens. we investigated constitutive and induced monoterpene responses of jack pine (pinus banksiana lamb.) to a number of damage types: a fungal associate of the mountain pine beetle (dendroctonus ponderosae hopkins), grosmannia clavigera (robinson-jeffrey & r.w. davidson); two phytohormones, methyl jasmonate (mj) and methyl salicylate (ms); simulated herbivory; and mechanical wounding. we only i ... | 2012 | 22659460 |