Program Book - 27th Fungal Genetics Conference

FULL POSTER SESSION ABSTRACTSincompatibility were highly enriched in the up-regulated gene set. In addition, incompatibility was characterized by an up-regulation of secondarymetabolism clusters, toxins and effector-like proteins, proteolytic and other hydrolytic activities. Genes for ribosome synthesis and energy productionwere in contrast down regulated. There was a significant overlap between regulated genes during incompatibility in P. anserina and N. crassa indicatingcommunality in the incompatibility responses in these two species. In P. anserina, the up regulated set was found to be enriched for proteins lackingorthologs in other species and chromosomal distribution of the up-regulated genes was uneven with up regulated genes enriched in genomic islands andcertain chromosomes. Globally, this study shows that transcriptome changes occurring during cell fusion incompatibility in P. anserina are massive andpleiotropic and in several aspects related to host-pathogen interactions described in other fungal species.294. Comparative Analysis of Putative Rhodopsins in Early Diverging Fungal Lineages. Steven Ahrendt 1 , Edgar Medina 1,2,3 , Jason Stajich 1 . 1) PlantPathology & Microbiology, University of California, Riverside, Riverside, CA; 2) Departamento de Ciencias Biológicas, Universidad de Los Andes, Bogotá,Colombia; 3) University Program in Genetics & Genomics and Department of Biology, Duke University, Durham, NC.Species belonging to the early diverging zoosporic fungal lineages (Blastocladiomycota, Chytridiomycota, Cryptomycota, and Neocallimastigomycota)reproduce via motile uniflagellated spores. Previous work has shown that some of these zoosporic fungi are phototaxic [1]; however, light sensing inzoosporic fungi has not been fully explored. The opsins are a broad class of photosensitive, seven-transmembrane G-protein coupled receptor proteins.One sub-class of opsin, the type 2 Rhodopsins, has previously only been identified in metazoan lineages [2]. Here we describe the identification andstructural/functional analyses of a putative type 2 rhodopsin in several species of recently sequenced zoosporic fungi: Batrachochytrium dendrobatidis,Spizellomyces punctatus, Allomyces macrogynus, Rozella allomycis, Gonapodya prolifera, and Homolaphlyctis polyrhiza. Computational modeling of the B.dendrobatidis and S. punctatus proteins indicates that they both adopt the seven-transmembrane helix conformation typical of GPCRs. Additionalobserved motifs are the so-called “ion lock” and conservation of the retinal binding pocket. The B. dendrobatidis protein sequence is notably lacking theconserved lysine residue, however this residue is present in the S. punctatus sequence. The number of identified Ga proteins is roughly consistent amongthe basal lineages, the Zygomycetes, and the Dikarya. Comparative genomics analyses of rhodopsin and flagellar genes in the basal lineages, Zygomycetes,and Dikarya show a correlation of flagellum and rhodopsin presence across the fungi, suggesting an evolutionary linkage between light-sensing andmotility during the transition from aquatic to terrestrial lifestyles. [1] Saranak & Foster. Nature. 1997. [2] Spudich et al. Ann. Rev. Cell Dev. Biol. 2000.295. Molecular Tools to Silence and Confirm Genes in Phytophthora Sojae. Felipe R. Arredondo 1 , Brett M. Tyler 1 , Shiv D. Kale 2 . 1) Botany and PlantPathology, Oregon State University, Corvallis, OR; 2) Virginia Bioinformatics Institute, Virginia Tech. Blacksburg, VA.Bioinformatics analysis is a powerful tool that decreases the number of possible leads to confirm the function of an interesting gene. These leads are onlyvirtual and theoretical but still have to be proven correct and accurate. PEG/ Protoplast transformation and particle bombardment transient expressionhave been part of Phytophthora molecular research for many years and valuable tools in gene identification and confirmation of function. Possibly thereare many hundreds of genes in Phytophthora species involved during the infection mechanism; the function of the majority of these virulence genes islargely unknown. Introducing genes into P. sojae via PEG/Protoplast transformation is a reliable tool that can confirm gene function by over-expression orsilencing. Another reliable tool is particle bombardment with the PDS1000 to transiently express intact or modified genes into soybean leaves. In thisposter I will introduce the mechanics of these powerful tools.296. Functional Characterization of Transcription Factor Genes, MoNIT4 and MoLEU3, in Magnaporthe oryzae. Jaehyuk Choi 1 , Soyeon Yoo 2 , Yong-HwanLee 1,2,3 . 1) Center for Fungal Pathogenesis; 2) Department of Agricultural Biotechnology; 3) Center for Fungal Genetic Resources, Plant Genomics andBreeding Institute, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.Rice blast disease caused by Magnaporthe oryzae is one of the most destructive threats to global rice production. Nitrogen metabolism has shown toplay an important role in pathogenicity of this fungus. Here, we characterized two genes encoding putative transcription factors belonging to theZn(II) 2Cys 6 family, MoNIT4 and MoLEU3, homologs of nit-4 in Neurospora crassa and leu3p in Saccharomyces cerevisiae, respectively. The DMonit4 mutantshowed reduction in conidiation and mycelial growth under nitrogen starvation compared to the wild-type. Addition of ammonium restored the growthdefects in the mutant. The expression of nitrate and nitrite reductase genes was significantly reduced in the mutants, suggesting that these genes areunder control of MoNIT4. The DMoleu3 mutant exhibits severe defects in conidiation and pathogenicity as well as mycelial growth under nitrogenstarvation. Addition of leucine complemented the defects in conidiation and mycelial growth in the DMoleu3 mutant. The decreased expression of 3-isopropylmalate dehydratase, 3-isopropylmalate dehydrogenase, and NADP-specific glutamate dehydrogenase genes supports that MoLEU3 functions as aregulator for leucine biosynthesis and ammonia assimilation pathways. Taken together, these findings will help to understand the nitrogen metabolismnetwork in M. oryzae and its role in the development of the rice blast disease.297. Comparative genomic analysis of world-wide Magnaporthe oryzae isolate collection. Jaeyoung Choi 1 , Gir-Won Lee 2 , Sook-Young Park 3 , JunhyunJeon 1 , Jaehyuk Choi 3 , Ki-Tae Kim 1 , Yong-Hwan Lee 1,3,4 . 1) Department of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Korea; 2)Department of Bioinformatics and Life Science, Soongsil University, Seoul 156-743, Korea; 3) Center for Fungal Pathogenesis; 4) Center for Fungal GeneticResources, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921,Korea.Since the genome sequence of Magnaporthe oryzae 70-15 was released, functional and comparative genomic researches have been extensively carriedout. However, characteristics of essential genes in M. oryzae are largely unknown. In this study, we sequenced 39 M. oryzae isolates collected from worldwideand analyzed to find the set of core genes. The average assembly size and the total number of predicted genes in the 39 M. oryzae genomes were37Mb and 14,517 genes, respectively. We found that a total of 5,148 genes turned out to be conserved at the amino acid level (identity ³ 80%) among the40 M. oryzae genomes including strain 70-15. To investigate a set of the core genes, we applied three different databases: Fungal Transcription FactorDatabase (FTFD; http://ftfd.snu.ac.kr/), Fungal Cytochrome P450 Database (FCPD; http://p450.riceblast.snu.ac.kr/) and Fungal Secretome Database (FSD;http://fsd.snu.ac.kr/). In addition, three in-house databases were used for the prediction of cell wall-degrading enzymes (CWDEs), peroxidases andlaccases. As a result, we found a core set of genes in M. oryzae: 932 secreted proteins, 269 transcription factors, 33 cytochrome P450 genes, 18 CWDEs, 17peroxidases and 5 laccases. Furthermore, we discovered an overlap of 38 genes between the above groups which have secretory potential. To archive andmanage those newly sequenced genomes, we developed the Magnaporthe Atlas (http://www.magnaporthe.org/) as a web-based solution. Our core geneset of M. oryzae will facilitate discovery of lineage-specific innovations with implications in coevolution with specific host cultivars.298. Functional characterization of two genes encoding putative Zn(II) 2Cys 6 transcription factors, MoCOD1 and MoCOD2 in Magnaporthe oryzae.Hyunjung Chung 1 , Sook-Young Park 2 , Jeahyuk Choi 2 , Junhyun Jeon 1 , Yong-Hwan Lee 1,2,3 . 1) Department of Agricultural Biotechnology; 2) Center for Fungal27th Fungal Genetics Conference | 193