​THE AUSTRALASIAN MYCOLOGICAL SOCIETY

2014 Scientific Meeting

 

The 2014 scientific meeting of the Australasian Mycological Society was held at the Ecosciences Precinct, Annerley, Brisbane, April 22-23rd (preceding the Queensland Fungi Festival April 24-26th)

 

 

 

 

The AMS meeting at the Ecosciences Precinct in Brisbane brought together Australian and international mycologists from a diversity of subdisciplines. Not surprisingly, the conference program covered a wide variety of mycological themes from infectious fungal diseases, molecular mycology and plant pathology to fungal ecology, systematics and applied mycology. More than 65 scientists attended the meeting which was held earlier in the year than usual to accommodate the autumn macrofungal field season for the conference foray and the Fungimap workshops which were held immediately after the AMS conference.

 

Proceedings began with a keynote address entitled “Cryptococcus neoformans – a designer fungus with serious intent” by Tania Sorrell (Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney). Tania delineated between C. neoformans and C. gattii in terms of ecological and host niches, biochemical pathways and disease manifestations. She then outlined current understanding of disease pathogenesis in C. neoformans, including the importance of both urease and phospholipase B in allowing the pathogen to pass the blood brain barrier and the debate on whether infectious propagules crossed this region as free cryptococci or within macrophages. A vivid description was given of the formation and currently known roles of cryptococcal microvesicles which act as “virulence bags” by releasing pathogenic factors externally to host tissues. Continued research of this area will obviously be critical to the development of therapeutic strategies for C. neoformans.

 

The first symposial session entitled “Infectious Fungal Diseases” followed neatly on, thematically, from the first keynote address. Monica Slavin (Peter MacCallum Cancer Centre and Victorian Infectious Disease Service, Melbourne) discussed new approaches for guiding antifungal therapy and outlined galactomannan tests, PCR and new imaging techniques such as PET scans for directing early treatment of invasive Aspergillosis. It was illuminating to have building site earth works highlighted as a major source of infectious fungal propagules in the nosocomial environment. Leona Campbell (School of Molecular Biosciences, University of Sydney) next outlined how virulence and the secretome are linked in Cryptococcus with virulent strains releasing a limited number of protein cohorts extracellularly (as opposed to hypovirulent strains) and thus better avoiding detection and destruction by the host. Ana Traven (Department of Biochemistry and Molecular Biology, Monash University) discussed how Candida albicans escapes the innate immune response by causing macrophage cell death. This is a two stage process that involves macrophage pyroptosis and subsequent mechanical destruction of cells by robust hyphal filaments. Asa Perez-Bercoff (John Curtin School of Medical Research, Australian National University) described genome sequencing, assembly and annotation of the emerging human pathogen, Scedosporium aurantiacum. This has been challenging as the next closest fungal species, Trichoderma virens was too distantly related to allow whole genome alignment. RNA sequencing of the WM 09.24 S. aurantiacum strain grown under different growth conditions has been pursued and has allowed the identification of genes that may be involved with virulence.

 

A diversity of fungal species and topics were featured next in the “Molecular Mycology” symposium. Julie Djordjevic (Centre for Infectious Diseases & Microbiology, Westmead Hospital) outlined signalling pathways during pathogenesis of C. neoformans. Fungal phospholipase C1 (PLC1) was shown to produce IP3 from PIP2 which was subsequently phosphorylated by an inositol polyphosphate kinase called Arg1. This latter molecule was essential for virulence and could provide a useful antifungal drug target. Kylie Boyce (Department of Genetics, The University of Melbourne) outlined studies of the pathogenicity genes of the dimorphic fungus, Penicillium marneffei. Tyrosine catabolism genes were shown to be involved in the release of N and C for fungal nutrition as well as the production of the brown pigment pyomelanin which could protect the pathogenic yeast cells against oxidative stress. Mark Wilkins (Systems Biology Initiative, University of New South Wales) described research into the surprisingly extensive protein methylation network of Saccharomyces cerevisiae. Evidence was presented that arginine methylation plays a hitherto unappreciated key role in facilitating protein-protein interactions in eukaryotes a finding that has major implications in terms of therapeutic interventions. As a change of pace, Anthony Borneman (The Australian Wine Research Institute, Adelaide) described research into genomic characterisation of strains of S. cerevisiae and the common spoilage yeast Dekkera bruxellensis.  Significant genetic diversity within both species was demonstrated via next generation sequencing and comparative genomics and it was hoped that this would assist with identifying the control of desirable and undesirable characteristics involved in industrial fermentation processes.

 

Plant pathogenesis is not usually the jurisdiction of the Australasian Mycological Society but organising a session on this topic proved an inspired and popular decision. The symposium opened with a talk by Don Gardiner (CSIRO Plant Industry, Brisbane) on the mechanisms Fusarium uses to combat the chemical defences of wheat. Specific examples discussed included a gene cluster encoded compound which detoxifies a common crop phytoalexin and an ABC transporter that exported an as yet unknown plant defence molecule. Not surprisingly, inactivation of these genes resulted in decreased pathogenesis. Liz Dann (Queensland Alliance for Agriculture and Food Innovation, University of Queensland) outlined the use of systemic acquired resistance in commercial crop protection programs. This can be triggered by chemical, physical and biological means and may confer resistance to fungal, bacterial, viral and nematode pathogens of crop species. Sue Thompson (Department of Agriculture, Fisheries and Forestry, Toowoomba) described twelve new species of Diaporthe from broad-acre, low tillage cropping systems. These important fungal pathogens, which cause damaging stem cankers in a number of crops, can persist in both stubble and herbicide-induced weed remnants. Celeste Linde (Research School of Biology, Australian National University) rounded out an excellent session with a description of how barley grass (Hordeum leporinum) provides a reservoir for the evolution of new pathogenic strains of Rhynchosporium commune (scald) that could impact on newly introduced resistant strains of barley.

 

Day two of the conference began with an amalgam of mycological topics in the “Proffered Papers” session. Susan Nuske (School of Marine and Tropical Biology, James Cook University) outlined the importance of mammals such as bettongs and potoroos in dispersing the spores of ectomycorrhizal fungi in Australian ecosystems. Tom May (Royal Botanic Gardens, Melbourne) described analysis of the distribution patterns of 200 macrofungal species within Australia. Although broad patterns of occurrence were demonstrated for many taxa, specific climatic requirements and available habitat were strong drivers of distribution within specific zones. Celeste Linde (Research School of Biology, Australian National University) discussed investigations of the mycorrhizal fungal specificity of terrestrial Australian orchid genera. ITS sequencing was sufficient to accurately distinguish the fungal partners of Chiloglottis, Drakaea, Paracaleana and Arthrochilus. The sharing of fungal partners within and between orchid genera indicated that mycorrhizal specificity was not a mechanism of speciation in orchids. Greg Bonito (Royal Botanic Gardens, Melbourne) presented results of an experiment whereby cuttings of multiple host plants and genotypes were grown in soils of different origins.  Profiles provided by MiSeq of fungal ITS and 28s rDNA highlighted the importance of soil origin (and not plant host species or genotype) as the strongest determinant of the fungal community of plant roots. Katharina Schwabenbauer (Molecular Mycology Research Laboratory, Westmead Hospital) finished the session with a description of the genetic diversity of Australian and European isolates of Scedosporium aurantiacum. Combined sequence analysis of six genes revealed separate clustering of the Australian and European samples and a higher diversity in the former group suggested that S. aurantiacum may have originated in Australia and dispersed to other world regions.

 

Morwenna Boddington (Faculty of Health, Engineering and Sciences, University of Southern Queensland) opened the “Fungal Systematics” session with morphological and molecular descriptions of potential new species of epigeous Russulaceae in South-East Queensland. Rachel Mapperson (Faculty of Health, Engineering and Sciences, University of Southern Queensland) discussed a range of previously undocumented endophytic, macro ascomycete taxa from dry rainforests in eastern Australia. Jeff Powell (Hawkesbury Institute for the Environment, University of Western Sydney) argued that the increasing use of next generation sequencing may have expanded the documentation of global fungal diversity but had diverted mycologists from understanding the ecological drivers of fungal diversity and its implications. He suggested that the broader mycological research community be encouraged to use physical and chemical fungal species characteristics (ie. a trait-based approach) to more fully understand the interactions between fungi and natural and managed environments. Laszlo Irinyi (Molecular Mycology Research Laboratory, Westmead Hospital) concluded the systematics session with an outline of the establishment of an online database of 2700 ITS sequences of 416 medically important fungi. This database may be expanded to include alternative genetic loci for a number of taxa.

 

A session on “Applied Mycology” outlined some of the significant roles fungi can have in industry, forestry and agriculture. Lisa-Marie Guilino (Department of Agriculture, Fisheries and Forestry, Queensland) began the symposium with a description of gut-inhabiting anaerobic fungi. These microbes have been recently molecularly characterised from the rumen of cattle and the fore stomach of kangaroos and are being investigated for their possible roles in fibre digestion for biofuel production.  Lesley Francis (Department of Agriculture, Fisheries and Forestry, Queensland) outlined her research on the basis  of natural decay resistance in forest and plantation timbers.  Polyphenols may protect timber via their toxic effects on decay fungi. In addition, timber waxes may prevent the accumulation of the water that is necessary for the activity of fungal-derived lignocellulolytic enzymes.  Vic Galea (School of Agriculture & Food Sciences, The University of Queensland) documented his research in using endophytic fungi to control two significant Australian weeds, Parkinsonia (Parkinsonia aculeata) and Prickly Acacia (Acacia nilotica). Field trials using endophytic inoculum inserted into weed stems are currently underway. Richie Robinson (Department of Parks & Wildlife, Western Australia) outlined his recent studies of Cortinarius diversity in the jarrah forests of South Western Australia. 118 Cortinarius morphospecies collected from field sites were further investigated by sequencing of ITS DNA. This analysis showed a general lack of congruence between morphological and molecular approaches, identified many cryptic species and highlighted the need for continued investigation of this large and significant ectomycorrhizal genus.

 

The final symposium of the conference was entitled “Fungi and Restoration” and covered a diversity of topics. The first speaker in this session, Jess Mowle (Hawkesbury Institute for the Environment, University of Western Sydney) described research on the microbial communities of the critically endangered Wollemi pine. The species appears to have its own unique community of mycorrhizal fungi and bacteria and this has implications for translocation procedures that are being used as a conservation strategy for the species. Cathal Daynes (Faculty of Agriculture, University of Sydney) demonstrated that compost and a diversity of arbuscular mycorrhizal fungi was necessary for the restoration of topsoil in mine spoil. Ash Martin (Microbiology Laboratories Australia, Adelaide) also highlighted the importance of mycorrhizal fungi in restored environments but warned against poor quality inocula, incorrect application and the pitfalls in monitoring procedures. Tendo Mukasa Mugerwa (School of Biological Sciences, University of Sydney) described research on the role of melanised root-associated fungi in positively influencing edaphic conditions.  Pot trials showed that 20 of 24 melanised root-associated fungi isolated from native Australian plants increased carbon levels in an aggregated carbon rich agricultural soil. Such a response may have been mediated by the release of melanin from cell walls of these fungi. The final speaker in the session was Kate Newman (Centre for Sustainable Ecosystem Restoration, University of Newcastle) who described the experimental inoculation of mine spoil with an array of soil microbes (rhizobia, mycorrhizal fungi, endophytes), and the addition of municipal waste compost and native plant seedlings. Although in its early stages, plant growth appeared to be enhanced with microbial inoculation alone but coal dust in the soil appears to be a confounding factor in interpreting experimental results.

The conference ended with the second keynote address given by Roy Halling from the Institute of Systematic Botany, New York Botanical Garden. The address, entitled “Location, Location, Location: Input from Boletography” highlighted the evolution in approaches to fungal biogeography studies, from the older macro and micro-morphological methods and mating strain compatibility tests, to more contemporary molecular procedures. Bolete mushrooms are pored members of the Agaricomycetes. They are obligate ectomycorrhizal fungi and essentially unculturable. Roy, who has studied this group worldwide, is intrigued by the apparent global occurrence of some taxa. How did some species come to be widely distributed? Was it by long distance spore dispersal such as Pisolithus moving from Australia to New Zealand or via anthropogenic means such as the introduction of Amanita muscaria and Chalciporus piperatus on Pinus seedlings to Nothofagus? Could the apparent wide distribution of bolete taxa be a remnant of pre Cretaceous land bridge migration? Modern molecular systematic work appears to be key to determining equivalence between widely dispersed bolete morphotypes.

 

In all, a successful conference with much interaction between the representatives of each of the mycological subdisciplines present. The social activities which included a fungal foray, networking reception and conference dinner were well attended and provided ideal opportunities for networking. It was wonderful to see a good number of enthusiastic students attending the meeting with many presenting either talks or posters of a very high standard. The award for best oral presentation went to Sue Thompson for her passionate talk on the implications of her findings in the extensive research she has undertaken to track down the complex of Diaporthe species lurking in broad acre crops and weed residues. Andrew Kettle was awarded the student poster prize for his eye catching synopsis of comprehensive research into a virulence strategy of plant pathogenic Fusarium infecting wheat that involves the degradation of the phytoalexin benzoxazolinones.  During the conference Susan Nuske was announced as the winner of the inaugural annual AMS small competitive grant. Susan will use the grant to pursue her research into the significance of mammal dispersal of ectomycorrhizal spores in the rainforests of tropical North Queensland. …

 

 We look forward to another enjoyable and valuable meeting during July  2015 in Canberra in association with the Australian Society for Microbiology. Watch the Upcoming Events page for further details .