Program Book - 27th Fungal Genetics Conference

FULL POSTER SESSION ABSTRACTSSciences, Dankook University, Cheonan 330-714, Republic of Korea.Cordyceps bassiana (= Beauveria bassiana) is a widely distributed entomopathogenic fungus, particularly important in the industry of biological controlagents against agricultural pests and considered as a model organism for understanding fungal entomopathogenicity. We conducted a genome datamining of C. bassiana C101 isolate for nonribosomal peptide synthetase (NRPS) and PKS-NRPS hybrid gene clusters. To identify NRPS related gene clusters,whole genome sequence of C. bassiana C101 was subjected to antiSMASH program with default settings. Their domain sequences were predicted basedon fungal-specific HMMER models using databases of Pfam and InterPro. A domain specificity signatures were derived by NRPSpredictor2 while substratespecificity prediction of the acyltransferase (AT) domains was based on web server SBSPKS. We identified 16 NRPS, 5 NRPS-like and 3 PKS-NRPS hybridgene clusters, of which three are known for their metabolites (i. g., beauvericin, bassianolide and tenellin). For transcriptome analysis of NRPS relatedgenes using Illumina RNA-Seq, C. bassiana C101 isolate was inoculated on SDAY, iron-, nitrogen- and lipid-rich media at 25°C and harvested to obtain itsmycelia after two weeks of incubation. The stromata and perithecia of C. bassiana were also cultivated on brown rice medium and harvested from 4 weeksto 8 weeks old cultures at weekly intervals. As a result, beauvericin synthetase, a NRPS synthesizing insecticidal compound beauvericin, was highlyexpressed at mycelium grown in dark on SDAY but not in stromata except very low expression at 8 weeks old stromata. Conversely, another NRPSbassianolide synthetase, synthesizing insecticidal compound bassianolide, was not detected under any condition except very low detection in 8 weeks oldstromata. Tenellin synthetase, a PKS-NRPS hybrid, was expressed only in stromata. Some NRPSs showed expression in both mycelia and stromata whileothers were expressed either in mycelia or stromata. In particular, the expression levels of beauvericin synthetase are correlated with the metabolicprofiling of beauvericin in mycelia and stromatal conditions, indicating that the detailed information of the expression levels of NRPSs can be used todiscover the metabolic diversity of C. bassiana with the further study of gene function and comparative metabolic profiling.277. Global analysis of the Colletotrichum gloeosporioides genome and transcriptome reveals a conserved role for pacC pH regulation in fungi. NoamAlkan 1 , Xiangchun Meng 3 , Eli Reuveni 1 , Gilgi Friedlander 1 , Serenella Sukno 4 , Michael Thon 4 , Robert Fluhr 1 , Dov Prusky 2 . 1) Plant Sciences, WeizmannInstitute of Science, Rehovot, Israel; 2) Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, BetDagan, Israel; 3) Fruit Tree Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China; 4) Department of Microbiology andGenetics, University of Salamanca, Villamayor, Spain.Colletotrichum gloeosporioides, a widely distributed economically important agent in postharvest fruit disease, thrives by massive secretion of ammonia.The alkalized environment hijacks host response and activates fungal pathogenicity genes. In contrast, other types of fungi acidify the environment fortheir optimal growth. In both cases the pacC transcription factor, with homologs in yeasts and fungi, exerts critical pH control of gene expression. Toexplore global aspects of pH-dependent gene expression, we sequenced the C. gloeosporioides genome and compared transcriptomes of WT and a DpacCmutant to examine pacC regulation. The 54 Mb C. gloeosporioides genome comprises 16,603 transcripts. Transcriptome analysis of the mutant showedthat DpacC regulates more than 5% of the fungal genome including; transporters to maintain cellular homeostasis, cell wall degrading enzymes to optimizepathogenicity and GATA-like transcription factors. The predictions were verified by monitoring gene expression in different media and during fruitinfection a well as by pathogenicity assessment of selected deletion mutants. Analyses showed over-representation of pacC binding sites in the promotersof the pacC up-regulated genes. However, in the promoters of the down-regulated genes GATA-like binding sites were dominant. The results suggestduality in global pacC control; direct regulation of alkaline-induced transcripts but indirect regulation, by activation of other transcription factors to downregulateacid expressed transcripts. To establish the generality of this scenario, conservation of pacC distribution was examined in genes selected byhomology from 5 different fungi that have contrasting alkaline or acidifying pathogenicity strategies. The results showed that irrespective of pathogencolonization strategy, the homologs of up-regulated genes had over-representation of pacC binding sites. Significantly, the homologs of down regulatedgenes revealed cross-genome over-representation of GATA transcription factor binding sites. Thus, regulation by pacC is a phylogenetically conservedfungal mechanism exerting dual pH control for maintaining homeostasis and pathogenicity in changing environments.278 WITHDRAWN279. Anisogramma anomala: a unique fungus with a huge genome. Guohong Cai, Thomas Molnar, Bradley Hillman. Plant Biology and Pathology, RutgersThe State University of New Jersey, New Brunswick, NJ.Anisogramma anomala (Ascomycota: Diaporthales) is the causal agent of hazelnut eastern filbert blight (EFB). This obligate and biotrophic fungus onlyreproduces sexually through ascospore. EFB is the most important disease of commercially grown hazelnut (European hazelnut), Corylus avellana, in theUnited States. It only causes minor disease on its natural host, the American hazel C. Americana, which is an understory shrub commonly found indeciduous forests in Northeast region of North America. Despite quarantine efforts, EFB was found in Washington in the late 1960s and reached Oregon’sWillamette Valley, the main hazelnut production area, in 1986. Commercial cultivars carrying a single locus from cultivar Gasaway confer completeresistance to EFB in the west coast. However, certain strains from the east can break the resistance. We sequenced an Oregon strain using Illumina GA IIXplatform. Approximately 26M 146 bp paired-end reads were used to produce a draft assembly with contig N 50 of 10,384 bp and scaffold N 50 of 32,987 bp.Excluding gaps, total assembly was 333.6 Mb. This is huge for a fungus with single nucleus. The genome size produced by draft assembly was corroboratedby flowcytometry, which measured the genome size at approximately 370 Mb. The genome has low GC ratio of 32%. Approximately 85% of assembledgenome is repetitive, and AT-rich sequences are enriched in the repetitive regions. We are exploring the genome sequences looking for answers to theuniqueness of this fungus.280. Leptosphaeria maculans 'brassicae': "Transposable Elements changed my life, I feel different now". Jonathan Grandaubert 1 , Conrad Schoch 2 ,Hossein Borhan 3 , Barbara Howlett 4 , Thierry Rouxel 1 . 1) INRA-BIOGER, Thiverval-Grignon, France; 2) NCBI, National Institutes of Health, Bethesda, MD, USA;3) AAF Saskatoon, Canada; 4) School of Botany, University of Melbourne, Australia.The Dothideomycetes phytopathogens Leptosphaeria maculans and Leptosphaeria biglobosa form a complex of 8 species and putative subspeciessuggested to have diverged “recently”. In 2007, the sequencing of an isolate of Leptosphaeria maculans 'brassicae' (Lmb) provided the first referencegenome for this fungus. The 45-Mb genome has an unusual bipartite structure, alternating large GC-equilibrated and AT-rich regions. These AT-rich regionscomprise one third of the genome and are mainly composed of mosaics of truncated Transposable Elements (TEs) postulated to have “invaded” thegenome 5-10 MYA; they also comprise 5% of the predicted genes of which 20% encode putative effectors. In these regions, both genes and TEs areaffected by Repeat Induced Point mutation (RIP). To investigate when and how genome expansion took place in the evolutionary series, and theconsequences it had on fungal adaptability and pathogenicity, the genomes of five members of the species complex showing contrasted host range andinfection abilities were sequenced. In silico comparison of the reference genome with that of 30-32-Mb genome of L. maculans 'lepidii' (Lml), L. biglobosa'brassicae', L. biglobosa 'thlaspii' and L. biglobosa 'canadensis', showed these species have a much more compact genome with a very low amount of TEs27th Fungal Genetics Conference | 189