BSPP News Summer 2001 - Online EditionThe Newsletter of the British Society for Plant Pathology
Number 39, Summer 2001
Fungal Genetics Conference XXI Asilomar, California, USA : 13 - 18 March 2001
The 21st Fungal Genetics meeting was held at the Asilomar conference center set in the beautiful state park in Pacific Grove, California. Over 600 participants attended from around the world and ranged from professors to graduate students. The four days of talks and poster presentations began with Ralph Dean from North Carolina State University. He told us about genome reconstruction and gene expression in the potential 'Bio-weapon' Magnapothea Grisea, for which his group has a framework for gene sequencing, an integrated data base, and a draft sequence of Chromosome 7.
Amongst the concurrent sessions in the first afternoon was a topic concerning metabolic organization and regulation. This contained an interesting talk by Erica Kothe from Friedrich Schiller University. Erica discussed the relationship between T. Vaccuniem and spruce roots and showed us the RTPCR and RNA fingerprinting work she has carried out to compare gene expression in compatible and incompatible interactions. This work has enabled the identification and purification of a 23kDa hydrophobin that is expressed in the cell walls of arial hyphae only during compatible symbiotic associations. Also in this session Mathew Tanzer from Paradigm Genetics Inc. talked of a new tool for the study of metabolism in filamentous fungi. The technique compares nutrient profiles by assaying 36 well plates in an automated procedure to observe gene function, clusters and similarities in a quantitative and objective way.
The next day began with talks about fungal-host interactions in which histone deacetylases, cAMP, G proteins and MAP kinases were all discussed. In the afternoon we heard more about G proteins and cAMP with Richard Goner from Rice University Houston, giving a clear and friendly account of a gene involved in the size regulation of fruiting bodies. The gene product is a large (450kDa) secreted factor that diffuses and increases motility while reducing adhesion of the cells it reaches via a cAMP signaling pathway. This causes appropriate sized groups to be formed and hence functional fruiting bodies.
The following day began with a similar theme of cell signaling and was highly concerned with the cytoskeleton. The session contained a talk by Susan Assinder from The University of Wales, Bangor who spoke about cell traffic in Aspergillus nidulans. She used various bio-imaging techniques to show us aspects of vesicle systems, secretion and the localization of the Sod C gene product a-cop, which is essential for polarized growth.
The final plenary session began with talks about the fungal genome. This included a clear and simple guide to crossing over (or break-dancing!) in meiosis of Coprinus by Mirian Zolan from Indiana University.
This conference was extremely friendly and showed great graphics as well as a large amount of enthusiasm for sharing information. It was brought to a close with a splendid conference dinner and an entertaining speech by N. Ronald Morris, M.D, who told us the story of Aspergillus nidulans. This was followed by a dazzling display of enthusiastic international dancing to 'The Amplified DNA' band, which was enjoyed by all.
Finally I would like to thank the BSPP and the School of Biosciences at Birmingham University for providing me with the financial support to attend this interesting and informative conference.
The University of Birmingham
The 21st Fungal Genetics Conference, organised by the Genetics Society of America, covered the whole range of fungal genetics, much of it out of the remit of a plant pathologist, but there was always something of interest going on. We arrived in the middle of the afternoon on March 13th after a scenic drive along the coast from San Francisco. The first day was just devoted to checking in, looking around the site and a social mixer, where a jet-lagged Nottingham contingent just about stayed up till 10pm.
The first plenary session contained talks on functional genomics. Ralph Dean summarised the efforts of an international consortium engaged in sequencing the genome of Magnaporthe grisea. A BAC library has been used to construct a physical map of the genome, and a draft sequence for chromosome 7 has been completed. Brett Tyler gave a talk on the genomics of Phytopthora with the aim of sequencing selected genomic regions from all species. On a more general level he compared the evolution of plant pathogenesis across the different kingdoms; did it evolve separately or did it occur through horizontal gene transfer?
Before the afternoon session we took the opportunity to see some of the wildlife along the coast. In some places sea otters, sea lions and millionaires playing golf can all be seen in their natural environment. It was soon back to work, with my pick of the afternoon sessions being fungal pathogenesis. Heidi Böhnert showed how she had used RAPDs to detect and isolate avirulence genes in Magnaporthe. These were confirmed by deletion mutants. Maarten de Waard explained how ATP-binding cassette transporters in Botrytis cinera caused multidrug resistance. These were overexpressed in the presence of fungicide and expelled it from the cell.
The evening poster session included my poster, so I was unable to have a look around, the session being spread over several different buildings.
Thursday morning saw plenary talks on fungal host interactions. James Kronstad described how mating type and signalling pathways in basidiomycete pathogens were related to virulence. Jonathan Walton explained how the high virulence of Chochiobolus carbonum on maize is due to production of HC-toxin. The genome is organised so that all the genes needed for HC-toxin production are present at a single locus, TOX2.
The long lunch break allowed time to venture onto the "playful" Pacific Ocean to see migrating whales. The afternoon session offered slightly less excitement from a plant pathology perspective. There were a number of talks on DNA repair. Gustavo Goldman and Sarah Lee McGuire gave talks on the roles of scaA and nimX2 in DNA damage response, respectively.
With over 150 posters on display space only allows a very limited summary. Marcelo Semighini had developed a RT-PCR real time assay to quantify expression levels of ABC multidrug resistance genes. Les Szabo had developed a partial genetic map of Puccinia graminis using RADPs and AFLPs. Avirulence genes had been mapped to seven linkage groups.
Friday morning talks were about cell biology. Among the topics covered were tip growth, vacuole components and regulation of hyphal elongation. Friday afternoon unfortunately had several interesting talks running concurrently. This was bit of a shame since some of the other sessions had seemed a little dry, plant pathology wise. Having sent spies to other sessions, I attended the population genetics session. Brett Couch gave a talk on population subdivision in Magnaporthe grisea. He had used a multilocus molecular marking system to analyse both geographical and host range. Single origins could be found for large geographic regions. There was evidence of possible three host jumps to rice. James Garton had done similar work with American populations of Ustilago maydis. Genetic differences were not correlated to geographical distance, possibly due to host plant constraint or the lack of time since the spread of agriculture across the continent.
Among the more eye-catching posters on Friday evening was that of Stefan Wirsel, who had used SEM morphology, ITS and actin sequences to identify four separate species of Cladasporium. Todd Ward demonstrated that the species phylogeny of Fusarium is not representative of the evolutionary history of the trichothecane gene cluster.
And so to Saturday. The morning session was devoted to talks on genome structure and maintainance. Carlo Cogoni talked about post transcriptional gene silencing. By comparing the processes observed across different species, it has been possible to identify a common genetic base for the phenomenon. David Perkins gave an overview of the study of fungal chromosome rearrangements. These have long been used in the study of other eukaryotes, but fungal geneticists have been late starters in the field. These are now being used to study a range of cellular activities, with future possibilities including phylogenetic studies.
After lunch there was again a variety of concurrent talks. The host-parasite coevolution session started with a flurry of talks about different methods of characterising avirulence genes. We then learnt about the efforts of the Ustilago maydis sequencing project from Jörg Kämper.
To finish off the conference, there was a banquet served by the hard working Asilomar staff, before an invited lecture by N. Ronald Morris, Aspergillus evangelist and allegedly top ten recording artist. He gave a light-hearted potted history of Aspergillus research, with frequent insults to any yeast geneticists present. The evening was rounded off by the Amplified DNA band and the always amusing sight of academics trying to dance. There were ad hoc workshops on Sunday morning, but this reporter had a plane to catch.
So after a week in (too) sunny California, it was back to the drizzle of Nottingham. I would like to thank BSPP for providing money towards my travel expenses.
University of Nottingham
'Waves which lap quietly about the jetties of Monterey grow louder and larger in the distance. and from all around, even in quiet weather, the low, distant, thrilling roar of the Pacific hangs over the coast and the adjacent country like smoke from a battle'. Robert Louis Stevenson
The Asilomar Conference Centre is an idyllic location for the gathering of fungal researchers from all around the world. The conference grounds consist of 107 acres of dunes and forests that support an array of wildlife including deer, woodpeckers and squirrels. The nearby harbour town, Monterey, used to be the capital of California under Spanish/ Mexican rule and for a short while was home to Robert Louis Stevenson.
As a final year PhD student, this was the first time that I had attended an overseas international conference. I was a little unsure what to expect. I was particularly nervous as I was attending the conference alone and had to present both a written and spoken paper. To my relief everyone was very friendly and accommodating, there was not a time when I felt uneasy or alone.
A wide variety of subject areas and fungal plant pathogens were represented and at times it was difficult to decide on which sessions to attend (for a full list of all abstracts submitted visit http://www.fgsc.net/fungalgenetics2001/abstracts.htm). As a molecular biologist, it was interesting for me to hear about the increasing number of fungal genomes that have been sequenced and published into databases. These include Neurospora crassa (www.genome.wi.mit.edu/annotation/fungi/neurospora), Candida albicans (www.sequence.stanford.edu/group/candida.html) and Cryptococcus neoformans (www.sequence.stanford.edu/group/C.neoformans/index.html). Ralph Dean described how in Magnaporthe grisea, a federated database(www.fungalgenomics.ncsu.edu) has been created and in addition, the Aspergillus nidulans community announced the completion of the genome-sequencing project (www.cereon.com). The importance of the development in genomic and proteomic technologies, for a better understanding of microbial genetic diversity and function was emphasised.
The most relevant and interesting session for me was the Mycosphaerella graminicola workshop, organised by Gert Kema. The workshop provided the M. graminicola community with a chance to review present knowledge and discuss future research. In the first half of the session, Gert described how avirulence is controlled by a single locus, suggesting that the host-pathogen interaction is a gene for gene relationship. Cees Waalwijk then went on to show how the avirulence locus was mapped to a single open reading frame (ORF43). He explained that some natural avirulent isolates do not carry the avirulence gene, indicating that additional avirulence genes must exist. Before the afternoon break, Kiichi Adachi gave an enlightening presentation on the development of the TAGKOTM (Transposon-array-gene-knockout) transformation system for high throughput gene disruption and functional analyses. Kiichi claimed that by creating disruption vectors (cosmid clones) with ~40kb of flanking region the targeted integration frequency increased by up to 28%. After coffee, I presented my spoken paper entitled "Vitamin deficient mutants of M. graminicola" and explained that by creating auxotrophic mutants requiring thiamine, I can go on to determine whether thiamine biosynthetic genes are pathogenicity determinants in this plant pathogen. The concluding discussion highlighted the problem that there is still no workable system for carrying out sexual crosses in vitro for this microorganism.
The conference ended with a banquet and an 'enjoyable' closing party that was entertained by 'The Amplified DNA Band'. The next morning I left the conference centre, with a hangover, and looked forward to the nine days that I had left to explore the wonders of California. I would like to thank Syngenta and the BSPP for funding my trip.
IACR Long Ashton