Program Book - 27th Fungal Genetics Conference

FULL POSTER SESSION ABSTRACTSparticipation of the RNAi machinery in these processes. In addition, different classes of sRNAs are differentially expressed between the WT and Ddcr2strains. An in depth analysis of features of these small RNAs, e.g. size, type of sRNAs and 5'nucleotide bias, show that those present in WT are lost in thesRNAs of the Ddcr2 strain. All together these data show that in Trichoderma atroviride, the RNAi machinery has a central role in endogenous processessuch as the development and fitness, beyond controlling the protection of genome against invasive nucleic acids as reported for other fungi.436. Genome-wide analysis of light responses in Mucor circinelloides. Victoriano Garre, Sergio López-García, Eusebio Navarro, Santiago Torres-Martínez.Departamento de Genética y Microbiología, Universidad de Murcia, 30100 Murcia, Spain.Light regulates developmental and physiological processes in a wide range of fungi. Particularly, Zygomycete fungi have developed complex mechanismsto control the responses to light that await detailed characterization at molecular level. The zygomycete Mucor circinelloides is a good model for thispurpose because its genome has been sequenced and several molecular tools are available. Mucor, like other Zygomycetes, has three white collar-1 genes(mcwc-1a, mcwc-1b and mcwc-1c) that code for proteins which present characteristics of photoreceptors. Each mcwc-1 gene controls a specific responseto light. Thus, mcwc-1a and mcwc-1c control phototropism and photocarotenogenesis, respectively, whereas the mcwc-1b function in regulation by lighthas not been proved. In order to deepen in the regulation by light in Mucor, a systematic approach using microarrays was followed to characterize whitelight-inducible transcriptional changes in wild-type and knockout mutants for each mcwc-1 gene. Analysis of microarray data revealed that light is mainly apositive signal for transcription in Mucor, as in other fungi, since 123 genes were up-regulated in the wild-type strain in response to light, whereas only 26were down-regulated, considering a threshold of threefold change. Genes strongly induced by light included genes known to be up-regulated by light, likethe carotenogenic gene carB (74-fold), cryptochrome (45-fold) and mcwc-1c (22-fold), supporting reliability of the microarray data. Although many of upregulatedgenes code for proteins implicated in protection against light-induced damage, several of them code for protein involved in signal transductionthat could be involved in light responses like phototropism. Transcriptomic analysis of mcwc-1 mutants showed that induction of around 60% of the genesis mediated by mcwc-1a, whereas only 1% is mediated by mcwc-1c and none is mediated by mcwc-1b, suggesting that mcwc-1a is the main photoreceptor.Searching for cis-acting regulatory motifs upstream of genes regulated by mcwc-1a identified consensus sequences similar to those found in lightregulated genes of Neurospora crassa. Moreover, the identification of a small group of genes regulated by the three mcwc-1 genes points out that thethree proteins form complexes to regulate gene expression. Funded by MINECO (BFU2012-32246), Spain.437. Gene expression profiling of the basidiomycetous fungus Lentinula edodes after light stimulation. H. Sano 1 , Y. Sakamoto 2 , M. Abe 3 , S. Kaneko 4 , M.Nakamura 1 , Y. Miyazaki 1 . 1) Department of Applied Microbiology, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki, Japan; 2) Departmentof Biological Resources Research, Iwate Biological Research Center, 22-174-4 Narita, Kitakami, Iwate 024-0003,Japan; 3) Forest and Forestry ResearchInstitute, Tokushima Agriculture, Forestry and Fisheries Technology Support Center, 5-69 Nanshocho, Tokushima, Tokushima 770-0045, Japan; 4)Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama,Kanagawa 226-8503, Japan.Light is an important environmental signal for various organisms and is known to regulate their physiological and developmental processes. In fungi, lightinfluences sexual and asexual reproductions, mycotoxin productions and pigmentation. Morphological differentiations of mushroom-forminghomobasidiomycetes are also affected by light and stimulation of light is one of the important factors regulating fruiting body formation. The molecularmechanisms regulated by light are well studied in ascomycetes, and a number of light-regulated genes are identified and are characterized. Inbasidiomycetes, the photoreceptor-encoding genes homologous to Neurospora crassa wc-1 have been isolated from several species and those geneticalevidences revealed the involvement in fruiting body formation. However, the details of light-sensing systems and light-dependent regulation of genes areunclear. In this study, we performed super serial analysis of gene expression (SuperSAGE) using Illumina/Solexa genetic analyzer and analyzed the changeof gene expressions stimulated by light during fruiting body formation in Lentinula edodes. The samples for high-throughput SuperSAGE were preparedfrom mycelia cultivated under darkness and after exposure to light with low temperature treatment. The mycelium which had been exposed to lightformed a number of primordium and developed into normal fruiting bodies, whereas the mycelium cultivated under darkness could produce noprimordium. The obtained transcriptome data showed that there were many kinds of genes expressed in L. edodes after light irradiation (5251 genes),compared with the data under darkness (2876 genes). The comparison analysis revealed that the expressions of 2500 genes were different between lightand dark condition, and that over 2000 genes were strongly transcribed in L. edodes after exposure to light. Light irradiation also caused the decrease inexpression levels of 500 genes. The up- and down-regulated genes were categorized by Gene Ontology and were assigned by the KEGG pathway mapping.These analyses suggested that several genes encoding putative fungal-specific proteins were regulated by light. The cataloged data of the expressed genesprovide valuable information on understanding of light-sensing system in L. edodes.438. Further Characterization of Surface Recognition Mechanisms in Magnaporthe oryzae. Guanghui Wang 1 , Xiaoying Zhou 2 , Guotian Li 2 , Jin-Rong Xu 1,2 .1) College of Plant protection, Northwest A & F University, Yangling, Shaanxi, China; 2) Department of Botany and Plant Pathology, Purdue Universtiy,West Lafayette, USA.Surface recognition and appressorium penetration are critical infection processes in the rice blast fungus Magnaporthe oryzae and many other plantpathogenic fungi. Various chemical and physical surface signals are known to be recognized by germ tubes to activate the Pmk1 MAP kinase that isconserved in fungal pathogens for regulating appressorium formation and penetration. Recently, the Msb2 mucin gene was found to function as a surfacesensor upstream from the Pmk1 pathway. However, it is not clear how is Msb2 activated and what is its relationship with other surface sensors. In thisstudy, we found that the cleavage domain and transmembrane helics are essential for Msb2 functions. Site-directly mutagenesis was used to verify twocandidate cleavage amino acid sites. In addition, we conducted deletion analysis with the cytoplasmic tail of Msb2 that likely plays a role in intracellularsignaling. We also assayed the effects of over-expressing the C-terminal region of Msb2 and identified proteins co-precipitated with it by affinitypurification. Because CBP1 and PTH11 are two other putative surface sensor genes, we also generated the msb2 cbp1 and msb2 pth11 double mutantsand triple mutants with sho1. The msb2 cbp1 mutant rarely formed appressoria and was non-pathogenic, indicating that Msb2 and Cbp1, the only twomucins in M. oryzae, may have overlapping functions in surface recognition. Detailed phenotype characterization of the msb2 pth11 and triple mutants areunder the way. A model of Msb2 activation and relationship among different receptors will be presented.439. Evidence of Microbial Epigenetics; Loss-of-function mutant of the Bck1 Homolog, CpBCK1, from the chestnut blight fungus Cryphonectria parasiticaresulted in the sectoring accompanied with the changes in DNA methylation. J.-M. Kim 1 , S.-H. Yun 2 , K.-Y. Jahng 2 , D.-H. Kim 2 . 1) Department of Bio-Environmental Chemistry, Wonkwang University, Iksan, Jeonbuk, South Korea; 2) Institute for Molecular Biology and Genetics, Center for Fungalpathogenesis, Chonbuk National University, Jeonju, Jeonbuk, South Korea.Cpbck1, encoding a mitogen-activated protein (MAP) kinase kinase kinase from the chestnut blight fungus Cryphonectria parasitica, is an ortholog of228