​THE AUSTRALASIAN MYCOLOGICAL SOCIETY

2015 Scientific Meeting

The 2015 scientific meeting of the Australasian Mycological Society was held at QT Canberra, July 14-16, in conjunction with the meeting of the Australian Microbiology Society 

 

 

 

The pre-conference foray involved a visit to the Li-Sun mushroom tunnel at Bowral on the NSW Highlands. This unique location, a former single track railway tunnel built in 1866, is used to grow an array of Asian mushrooms for markets in Australia and overseas. AMS visitors were conducted on a tour of the facilities by the operator, Dr. Noel Arrold. Constant low temperature of 16ºC and humidity of 80% are used to grow hundreds of containers of a variety of fungi. These included chestnut mushroom (Agrocybe aegerita), Enoki or winter mushroom (Flammulina velutipes), king brown (Pleurotus eryngii), Nameko (Pholiota nameko), oyster (Pleurotus sp.), Shiitake (Lentinula edodes), Shimejii (Lyophyllum shimejii), swiss brown (Agaricus bisporus) and wood ear (Auricularia sp.). This was a remarkable facility and one of the more memorable conference forays the AMS has run over the years.

   

Day two of the conference was held in conjunction with the Australian Society for Microbiology (ASM) at the QT Hotel. Proceedings began with a plenary session by Judith Berman (Tel Aviv University) on genome dynamics and drug resistance in Candida albicans. In her address, Dr. Berman discussed how ploidy state and ploidy shift affect pathogen evolution and survival in response to exposure to stresses such as anti-fungal drugs. Her research has shown that aneuploidy can be a mechanism of resistance of Candida to the widely used antifungal drug, fluconazole. In addition fluconazole can induce changes in cell cycle progression that lead to whole ploidy shifts in the pathogen and subsequent drug resistance. Following morning tea, delegates could choose from a number of joint AMS-ASM concurrent symposia. In the session entitled “Ecosystem Health”, Jonathon Plett (University of Western Sydney) outlined research into the impacts of climate change (elevated CO2 and drought) on Australian soil fungi, particularly ectomycorrhizal taxa. Glasshouse experiments with two Eucalyptus species indicated that a specific root-fungal community was induced by elevated CO2. Microcosm transcriptomic experiments showed that, at elevated CO2, Eucalyptus grandis hosts varied in their response to different ectomycorrhizal Pisolithus taxa with a correlated substantial shift in root gene expression. This suggests that climate change may have important subsequent impacts on the establishment of the mycorrhizal associations of plant species. Jen Wiltshire (La Trobe University) discussed research into the role of microbial communities in the maintenance of the high plant diversity commonly seen in rainforest ecosystems. Preliminary research on tropical rainforests at Davies Creek in north Queensland suggest that each adult tree species associates with a distinct fungal community, which could potentially inhibit the growth of common species seedlings near conspecific neighbours.  In the “Host Pathogen Interactions” session, Peter Solomon (Australian National University (ANU)) discussed the mechanism and role of small cysteine-rich effector proteins in Parastagonospora nodorum infection of wheat. It was hypothesised that these effectors interact with specific dominant PR1 host proteins leading to a programmed cell death response and disease in wheat. Alex Adrianopolous (University of Melbourne) outlined the molecular control of the dimorphic switch in the human fungal pathogen, Talaromyces marneffii. In his research he is using a combination of “omics” methods including metabolomics to define the metabolic processes underlying dimorphic switching. Sophia Lev (Westmead Millennium Institute) explained the role of fungal inositol pyrophosphate IP7 in host-pathogen interaction and virulence of Cryptococcus neoformans. The IP7 signalling molecule appears to be essential for multiple yeast cellular functions that promote fungal adaptation to the mammalian host environment and influences yeast recognition by the host immune response. Tracey Steinrucken (University of Western Sydney and CSIRO) outlined results of glasshouse experiments whereby endophytic fungal pathogens were shown to cause dieback disease in the invasive tree Parkinsonia aculenta L. when combined with water stress and thus could have potential applicability as biocontrol agents.

 

A combined AMS/ASM proffered papers session followed lunch. Presentations included Desmarini Desmarini (Westmead Millennium Institute for Medical Research, University of Sydney) who spoke on phosphate acquisition strategies in Cryptococcus neofomans and Cecilia Li (Westmead Millennium Institute for Medical Research, University of Sydney) who discussed the role of inositol polyphosphate kinase (Ipk1) in cryptococcal drug tolerance and pathogenicity. Jeff Powell (University of Western Sydney) described research into the drivers of fungal and bacterial community assemblages in soils and Linda Henderson (University of Sydney) outlined the negative effects of heavy metals on the growth, reproduction and attachment rates of zoosporic fungi in soils.

 

A second round of AMS-ASM concurrent symposia followed afternoon tea. In the “Omics and Systems Biology” session, Judith Berman (Tel Aviv University) discussed the importance of centromere, origin of replication and telomeric region flexibility in maintaining the integrity of the Candida albicans genome. Megan McDonald (ANU) outlined an investigation into genes potentially encoding effector molecules in the wheat pathogen Zymoseptoria tritici. Whole genome re-sequencing and development of a python tool, PhyBi is being used to identify potential effector encoding regions in 13 core chromosomes of a number of virulent phenotypes of the pathogen. Marc Wilkins (University of New South Wales) outlined analyses of the yeast methylproteome to identify methylated proteins, associated methyltransferases and specific methylation sites within proteins. Knockout studies were used to link specific methyltransferases to specific methylation events, while enzyme-protein links were determined via a combination of recombinant protein-enzyme studies, in vivo methylation assays and/or the incubation of protein arrays with recombinant enzymes. A novel conditional two-hybrid system was also developed to demonstrate that methylation of arginine groups can control protein-protein interactions in eukaryotes.  James Fraser (University of Queensland) discussed recent research in his group investigating the plasticity of the genome of Cryptococcus neoformans. His investigations suggest, that in fact, the genome of C. neoformans is very stable and that in 20 million years of evolution only six inversions and one translocation have occurred in C. neoformans var grubii. Part of the effectiveness of the pathogen, however, appears to lie in its capacity to undergo major chromosomal rearrangements when required to adapt to changed environmental conditions, such as the presence of antifungal drugs.

The day concluded with a well-attended and highly enjoyable AMS conference dinner at University House at the ANU.

 

Day three of the conference began at the Innovations Theatre at the ANU with a welcome address by the AMS President, John Dearnaley. The society is celebrating its 20th birthday and the achievements of the AMS over this time, were outlined. Of particular mention was the hosting of the International Mycological Congress in Cairns in 2006 and the role the society is playing in strengthening the discipline of mycology in Australasia through regular holding of our scientific conferences and the introduction of a research award targeted at students and early career researchers. In honour of the society’s 20th birthday, a new logo was also launched. The logo was adapted from an original Heino Lepp drawing by Bevan Weir and a New Zealand graphic artist. It depicts a mycelium emanating from a fungal spore and represents the many sub disciplines of the Society

 

The day three plenary session was presented by Adrienne Hardham (ANU). Adrienne outlined the research her laboratory has been conducting into the cellular and molecular mechanisms of pathogenicity in Phytophthora. A particular focus has been the role of zoospore peripheral vesicles in the process of infection of plant tissues. Advanced microscopy techniques such as immunocytochemical labelling and GFP-tagging, as well as molecular genetics approaches, have elucidated the roles of these vesicles in enabling adhesion to plant roots and for providing a store of proteins used by the pathogen in invasion of host tissues.

Following on from the day three plenary session, was a symposium on plant pathogen interactions. Kim Plummer outlined the search for effector genes in Venturia spp. (the casual agents of scab diseases of fruit trees). Candidate genes have been identified by comparative genomics of whole genome sequences of Venturia isolates with different host specificities. Don Gardiner (CSIRO) discussed research on virulence mechanisms in the Fusarium-wheat pathosystem with the sesquiterpenoids a particular present focus of his research. Alex Idnurm (University of Melbourne) described research into the mechanisms that Leptosphaeria maculans uses to cause black-leg canker disease in canola including expression of cell wall-degrading enzymes, cerato-platanins and currently uncharacterised secreted proteins. Ann-Maree Catanzariti (ANU) finished the session with a description of the discovery and characterisation of small secreted effector proteins formed by the rust pathogen, Melampsora lini, during infection of flax plants.

 

A session entitled “Fungal Ecology”, followed morning tea. Jennifer Walker (University of Western Sydney) spoke on mycorrhizal dynamics in Eucalyptus species. Her research has shown that ectomycorrhizal (ECM) fungal colonisation of Eucalyptus seedlings increases with age of the host, is highest in unfertilised experimental soils and that the ECM fungal communities are specific for each host Eucalyptus species. Eleonora Egidi (Latrobe University) described research into the effects of repeated prescribed burning in a native grassy ecosystem on fungal communities. Automated ribosomal intergenic spacer fingerprint analysis have shown that low frequent fires led to an increase in exotic plants and a concomitant increase in a less fire-adapted fungal community. Hayley Ridgway (Lincoln University) outlined research into the arbuscular mycorrhizal (AM) fungi of two important New Zealand medicinal plants, Leptospermum scoparium and Sophora spp. Two experimental approaches ie. direct DNA sequencing of root DNA and baiting in sterile pot culture, appear to be necessary to identify the complete AM community of these plants. Frank Gleason (University of Sydney) completed the session with a description of the fungal (eg. Phylum Chytridiomycota) and fungal-like parasites (eg. Phylum Oomycota) of vertebrates. Considerable research such as mode of transmission, environmental influences and effective treatment options is still needed for many of these pathogens.

 

Over the lunch break, a Fungal Skills Workshop was run for students and early career researchers. This workshop was organised by the AMS student representative, Susan Nuske, and featured four established scientists from different mycological disciplines including Medical Mycology (Ana Traven), Fungal Ecology (Jeff Powell), Applied Mycology (Diana Leemon) and Fungal Systematics (Tom May). Each presenter outlined what had inspired them to become a mycologist, the skills they had acquired which had been instrumental in their careers and how young scientists could gain these skills. This workshop, a first for an AMS conference, proved very successful, with many students and early career researchers taking the opportunity to attend, ask questions of the panel and contribute to the discussions.

 

Symposium three, entitled “Molecular Mycology” began with a presentation by Ben Schulz (University of Queensland). Ben outlined how the cell wall glycoproteins in Saccharomyces cerevisiae have been used as model substrates to investigate the molecular mechanisms regulating N-glycosylation in eukaryotic cells. His research has shown that site-specific N-glycosylation occurs via direct physical interactions between polypeptides and two ER localised oligosaccharyltransferase enzymes in wild type yeast. Wieland Meyer (The University of Sydney) described investigations of three major new subtypes of Cryptococcus gattii identified in the Pacific North West, VGIIa, VGIIb and VGIIc. MLST analysis and whole genome sequencing suggested a South American origin for these subtypes. Gene disruption studies of a collagen binding domain of the VGIIa subtype collagenase suggests that this protein could be an important component in pulmonary disease caused by the pathogen. Richard Cannon (University of Otago) outlined research into methods to overcome fluconazole resistance seen in Candida albicans. His investigations have shown that the D-octapeptide drug, RC21v3, increases sensitivity to fluconazole by targeting the extracellular loops on the Candida ATP-binding cassette (ABC) efflux pump, Cdr1. Mark Prescott (Monash University) concluded the session with a description of his research into the molecular control of mitophagy in eukaryotes. Yeast cells lacking expression of OTP1 have a delayed mitophagy phenotype. The OTP1  protein is localised to the trans Golgi and appears to interact with the Uth1 glucan synthase to enact mitochondrial autophagy.

 

Tom May (Royal Botanic Gardens, Melbourne) was the first speaker in the next symposial session, “Systematics”. Tom outlined potential modifications to the international code of nomenclature (ICN) in support of modern fungal taxonomy including possible transfer of governance of fungal taxonomy matters to the International Mycological Congresses, more pragmatic considerations of type specimens (including wider utilisation of molecular data), “one name one fungus” and a recommendation for a synchronised world fungal name checklist by more closely linking the world’s three major fungal name registration databases, Fungal Names, Index Fungorum and Mycobank. Morwenna Boddington (University of Southern Queensland) next discussed some of the advantages and disadvantages of molecular approaches in taxonomic studies of the Australian Russulaceae. These ECM fungi have been particularly recalcitrant to genomic analysis but modification of fruit body sampling procedures and DNA processing and analysis represent potential solutions. Cecile Gueidan (Australian National Herbarium) described phylogenetic studies of the tropical lichen family, Pyrenulaceae. Research using FTA classic cards has enabled effective collection of genomic DNA from specimens from SE Asia and Brazil and has provided new insight into genus and species concepts in the family. Michael Whitehead (ANU) finally, outlined molecular characterisation of the Sebacina partners of members of the Caladenia group of Australian terrestrial orchids. Specificity within this orchid genus varies widely with some taxa associating with multiple Sebacina OTUs while others hosting only single fungal lineages. This latter, narrow specificity does not appear to be a determining factor in causing rarity in the associated Caladenia species.

 

The final session of the conference was entitled “Applied Mycology”. Jess Mowle (University of Western Sydney) outlined research on the abiotic and biotic conditions (including soil microbes) that are critical for translocation success in the critically endangered Wollemi Pine. Ignatius Pang (University of New South Wales) described transcriptomic studies of Saccharomyces cerevisiae when treated with a combination of the iron-chelator, lactoferrin and the antifungal drug, amphotericin B. The synergistic inhibitory effect appears to be due to the impacts on genes involved with iron and zinc homeostasis, making cells unable to respond to stress. Andrew Milgate (NSW DPI) discussed the emergence of fungicide resistance genes in the plant pathogen, Zymoseptoria tritici and its potential impacts on the Australian wheat industry. Rosamond Godwin finished the session with an outline of the development of commercial formulations of a Metarhizium bio-control agent for house fly control in cattle feedlots.

The final speaker of the conference was Susan Nuske (James Cook University), the inaugural winner of the AMS Research Award in 2014.  She had used her research funds to support PhD research on mammalian dispersal of ECM fungi in tropical Queensland.  In her talk she outlined the results of a literature review on the diversity, abundance and seasonality of fungi within mammalian diets. She also had gathered data on the home range of mammal species as an indirect measure for dispersal distance of ECM fungal species. The results of the study highlight Potoroo species (eg. the northern Bettong (Bettongia tropica) and the eastern Bettong (Bettongia gaimadi)) and the swamp wallaby (Wallabia bicolor) as significant mammals for maintaining diverse ECM fungal communities.

 

In all, a very successful conference with a wide diversity of mycological sub disciplines represented.  It was great to see a large number of students presenting their work in articulate talks or in well compiled conference posters. AMS vice president, Julie Djordjevic presented the Jack Warcup student conference awards to Cecilia Li and Tracey Steinbrucken for their excellent symposial presentations on day two of the meeting. We look forward to another enjoyable and valuable conference in May 2016 in Queenstown, New Zealand in conjunction with the Fungal Network of New Zealand. Stay tuned to the AMS website or our monthly newsletters for further details (www.australasianmycologicalsociety.com).