The antifeedant action of climacodon septentrionalis and two species of sphaerobolus to hyphal grazing by the fungus-feeding nematode aphelenchoides sp.

Fungi are ubiquitous in forest ecosystems and are, collectively, a major force in driving nutrient and organic matter availability and cycling. Some saprotrophic and mycorrhizal fungi are characterized by a perennial vegetative body, delayed sexual reproduction, and a relatively long lifespan. Such fungi are exposed to a barrage of antagonistic forces throughout their existence, one notable stress being invertebrate grazing. It is suggested that fungi with perennial mycelia must have developed means to deter grazing of their hyphal networks by pervasive mycophagist invertebrates.Controlled inoculation studies with a mycophagous nematode, Aphelenchoides sp., and isolates representing 78 fungal species were conducted to investigate the presence of possible antifeedants. These in vitro pairings resulted in the discovery of two novel antifeedant mechanisms in three species of fungi. In the presence of the saprotrophic fungi Sphaerobolus stellatus and S. iowensis, the anterior portion of nematodes became encapsulated in a material of unknown composition. This encapsulation phenomenon effectively prevented further hyphal grazing by obstructing stylet extension, which resulted in the eventual death of the nematode. Nematodes that died as a result of the encapsulation were never colonized or consumed by the fungus. It is hypothesized that the encapsulating material originates from modified hyphal cells, referred to as gloeocystidia, and is liberated when the cells are punctured by the nematode stylet. The wood-decaying fungus Climacodon septentrionalis was found to produce tall, stalked secretory cells in abundance on the aerial mycelia of the colony. Nematodes were enveloped and immobilized by droplets produced at the apices of the secretory cells. Immobilized nematodes were rarely colonized by the fungus and dead individuals persisted for weeks. A media study was employed to investigate the effect of nutrient concentration on the in vitro production of secretory cells. The discovery of novel antifeedants which mitigate damage caused to the mycelial network by grazing invertebrates offers a stimulus for further investigation into the interactions between fungi and their co-inhabiting microfauna. Keywords: Antifeedant, defence mechanism, fungivory, grazing responses, mycology, mycophagy, perennial mycelium

A Brief Survey of Mycophagy in Ruffed Grouse, Bonasa umbellus, from Northwestern Ontario

There are few published observations regarding the phenomenon of mycophagy in birds, the Ruffed Grouse being no exception. Twenty hunter-killed Ruffed Grouse crops were acquired in the Thunder Bay District from 22 September to 18 October, 2010, and examined for the presence of consumed fungal tissue. Four crops were found to contain intact remains of fruiting bodies. Based on cystidia and spore morphological characters, the specimens recovered were found to belong to three genera: Lactarius, Russula, and Melanoleuca. The results of this brief survey suggest the possible importance of mycophagy in the seasonal diet of the Ruffed Grouse, and indicate the need for further investigation

Governor Patrick Signs Bill to Control Health Care Costs

Surveys of foliar endophytes from the Acadian forest region over the past three decades have identified numerous phylogenetically diverse fungi producing natural products toxic to forest pests and diseases. The life histories of some conifer endophytes can be restricted to plant foliage or may include saprotrophic phases on other plants tissues or even alternate hosts. Considering the potentially broad host preferences of conifer endophytes we explored fungi isolated from understory species and their metabolites as part of an ongoing investigation of fungal biodiversity from the Acadian forest. We report a hitherto unidentified Xylariomycetidae species isolated from symptomatic Labrador tea (Rhododendron groenlandicum) leaves and mountain laurel (Kalmia latifolia) collected in coastal southern New Brunswick, Canada. Morphological and phylogenetic evidence demonstrated the unknown species was a novel Synnemapestaloides (Sporocadaceae) species, described here as Syn. ericacearum. A preliminary screening assay indicated that the culture filtrate extract of the new species was potently antifungal towards the biotrophic pathogen Microbotryum violaceum, warranting an investigation of its natural products. Two natural products possessing a rare 1,3-benzodioxin-4-one scaffold, synnemadoxins A-B (1-2), and their postulated precursor, synnemadiacid A (3), were characterized as new structures and assessed for antimicrobial activity. All isolated compounds elicited in vitro inhibitory antifungal activity towards M. violaceum at 2.3 μg mL-1 and moderate antibiotic activity. Further, the characterization of synnemadoxins A-B provided a perspective on the biosynthesis of some related 1,3-benzodioxin-4-ones produced by other fungi within the Xylariales

A Brief Survey of Mycophagy in Ruffed Grouse, <em>Bonasa umbellus</em>, from Northwestern Ontario

Visual inspection is often used to assess the condition of railway bridges at discrete points in time, an approach that can be subjective and possibly unsafe. Alternatively, certain bridges have their condition assessed via the installation of a large number of sensors. These sensors can be costly to place, power and maintain. Therefore, reducing their numbers and maximizing the extracted information is of utmost importance. In addition, evaluating bridge condition from measured response can be quite challenging due to loading and environmental variations, especially when a limited number of sensors are used. The focus of this research is to develop an automated hybrid experimental-numerical framework to detect and locate damage and estimate its intensity. The framework was developed analytically, based on Proper Orthogonal Modes (POMs) and Artificial Neural Networks (ANNs), and validated experimentally using 1 and 8 weeks of measured strains collected from a monitoring system placed onto an in-service, multi-span, railway bridge. The analytical work involved using three sensor instrumentation sets and investigated structural response for two bridge spans of different type and size. To generate training data for the ANNs, Modeling uncertainties that could lead to erroneous indication or omission of damage are incorporated into framework development via a systematic analyses. The procedure was based on synergizing POMs extracted from measured structural response and POMs calculated from the numerical model with a robust damage feature independent of level and location of modeling uncertainty. A hybrid experimental-numerical approach was developed and implemented to estimate damage scenario POMs from field measured strains. ANNs were trained and tested using these POMs with DL and DI being detected. These results show the promise of the POD-ANN method as a robust, real-time fatigue damage detection tool for steel railway bridges

Fungal Endophytes: Discovering What Lies within Some of Canada’s Oldest and Most Resilient Grapevines

Plant diseases and pests reduce crop yields, accounting for global crop losses of 30% to 50%. In conventional agricultural production systems, these losses are typically controlled by applying chemical pesticides. However, public pressure is mounting to curtail agrochemical use. In this context, employing beneficial endophytic microorganisms is an increasingly attractive alternative to the use of conventional chemical pesticides in agriculture. A multitude of fungal endophytes are naturally present in plants, producing enzymes, small peptides, and secondary metabolites due to their bioactivity, which can protect hosts from pathogens, pests, and abiotic stresses. The use of beneficial endophytic microorganisms in agriculture is an increasingly attractive alternative to conventional pesticides. The aim of this study was to characterize fungal endophytes isolated from apparently healthy, feral wine grapes in eastern Canada that have grown without agrochemical inputs for decades. Host plants ranged from unknown seedlings to long-lost cultivars not widely propagated since the 1800s. HPLC-MS was used to identify unique endophyte-derived chemical compounds in the host plants, while dual-culture competition assays showed a range in endophytes’ ability to suppress the mycelial growth of Botrytis, which is typically controlled in viticulture with pesticides. Twelve of the most promising fungal endophytes isolated were identified using multilocus sequencing and morphology, while DNA barcoding was employed to identify some of their host vines. These fungal endophyte isolates, which consisted of both known and putative novel strains, belonged to seven genera in six families and five orders of Ascomycota. Exploring the fungal endophytes in these specimens may yield clues to the vines’ survival and lead to the discovery of novel biocontrol agents

Observed COSY (bold) and key HMBC (blue) correlations for synnemadoxin A (1) and synnemadiacid A (3).

<p>Observed COSY (bold) and key HMBC (blue) correlations for synnemadoxin A (1) and synnemadiacid A (3).</p

Structures of new 1,3-benzodioxin-4-ones synnemadoxins A-B (1–2) and synnemadiacid A (3) characterized from <i>Syn</i>. <i>ericacearum</i> DAOMC 250336.

<p>Structures of new 1,3-benzodioxin-4-ones synnemadoxins A-B (1–2) and synnemadiacid A (3) characterized from <i>Syn</i>. <i>ericacearum</i> DAOMC 250336.</p

Phthalides produced by Coccomyces strobi (Rhytismataceae, Rhytismatales) isolated from needles of Pinus strobus

As part of a broad survey of the metabolites produced by foliar endophytes of conifers, a strain was isolated from surface-sterilized needles collected from eastern white pine on the north shore of Lake Huron, Ontario. The isolate was sterile in culture. Species identity was not resolved by ITS sequence because of the absence of corresponding sequences in public sequence databases, however the strain was placed in Rhytismataceae (Rhytismatales). Field collections targeting Rhytismataceae species on Pinus strobus were conducted enabling the isolate to be identified as Coccomyces strobi. An extract of the culture filtrate demonstrated moderate antifungal activity. Two new phthalides, (±)-strobides A-B (1-2) and the known phytotoxin cyclopaldic acid (3) were characterized from C. strobi DAOMC 251937. This is the first record of the occurrence of this species as a foliar endophyte. Previous reports have suggested that it is a cambium endophyte associated with small cankers on branches. The production of the phytotoxin cyclopaldic acid suggests that C. strobi is a weak opportunistic pathogen, switching from an endophytic to a pathogenic phase when the host tissue becomes weakened

¹H (400 MHz) and ¹³C (100 MHz) NMR data for synnemadiacid A (3) CD₃OD.

<p>¹H (400 MHz) and ¹³C (100 MHz) NMR data for synnemadiacid A (3) CD₃OD.</p