VAAM-Jahrestagung 2012 18.–21. März in Tübingen

77phytochrome FphA for red light sensing and the White Collar homologueLreA for blue light detection. A central regulator is the Velvet protein, anFphA interaction partner [2].Here, we report about a novel Velvet interaction partner, VipA (velvetinteracting protein A). VipA is a 334aa protein including a FAR1 domain.FAR1 proteins are well known from plants like Arabidopsis thalianawhere members of this protein family are involved in phytochromecontrolled far-red light responses [3,4]. In A. nidulans a vipA deletionstrain produced only 36% of conidiospores compared to wildtype. Thisfinding points to an activating role of VipA in asexual development. Incontrast VeA shows an inhibitory effect [5]. VeA - VipA interaction wasshown by yeast-two hybrid analysis and bimolecular fluorescencecomplementation. The two proteins interact in the nuclei. VipA representsa new element in the regulatory network of spore formation in A. nidulans.Detailed analyses on gene regulation through VipA and its relation to otherlight regulators are on the way.1. Rodriguez-Romero J. et al. (2010) Annu Rev Microbiol 64: 585-610.2. Bayram O. et al. (2010) Fungal Genet Biol 47: 900-908.3. Hudson M. et al. (1999) Genes Dev 13: 2017-2027.4. Lin R., Wang H. (2004) Plant Physiol 136: 4010-4022.5. Calvo A.M. (2008) Fungal Genet Biol 45: 1053-1061.FUV003Alternative splicing in the fungal kingdomK. Grützmann* 1 , K. Szafranski 2 , M. Pohl 1 , K. Voigt 3 , A. Petzold 2 , S. Schuster 11 University Jena, Department of Bioinformatics, Jena, Germany2 Leibniz Institute for Age Research, Fritz Lipmann Institute, GenomeAnalysis, Jena, Germany3 Leibniz Institute for Natural Product Research and Infection Biology andUniversity of Jena, Jena Microbial Resource Collection, Jena, GermanyDuring gene expression of higher eukaryotes, alternative splicing (AS) canproduce various isoforms from one primary transcript. Thus, AS is thoughtto increase a cell's coding potential from a limited gene inventory.Although AS is common in higher plants and animals, its extent and use infungi is mostly unknown. We undertook a genome-wide investigation ofalternative splicing in 28 fungal species from the three phyla Ascomycota,Basidiomycota and Mucoromycotina, applying current bioinformatics datamining techniques. Our analysis reveals that on average over theinvestigated fungi, 6.2% of the genes are associated with AS.Cryptococcus neoformans and Coccidioidis immitis show outstandingrates of 18% and 13%, respectively. Intron retention is the predominant AStype in fungi, whereas exon skipping is very rare. The investigatedBasidiomycota have on average higher AS rates (8.6%) and more diversecategories of AS affected genes than the Ascomycota (AS rate 7.0%,excluding yeasts). Contrarily, AS is nearly absent in strict yeasts. Wehypothesize that AS is rather common in many fungi and could facilitatemycelial and thallic complexity.FUV004Transcription factors controlling sporulation in Magnaporthe oryzaeA. Yemelin*, S. Matheis, E. Thines, K. Andresen, A.J. FosterInstitue of Biotechnology and Drug Research (IBWF), Plant protection,Kaiserslautern, GermanyThe Magnaporthe oryzae FLB3 and FLB4 transcription factor-encodinggenes were deleted. Analysis of resultant mutants demonstrated that Flb4pis essential for spore formation and that strains lacking this gene had‘fluffy’ colony morphology due to an inability to complete conidiophoreformation. Meanwhile Flb3p is required for normal levels of aerialmycelium formation. Using microarray analysis we identified genesdependent on both transcription factors. This analysis revealed that thetranscription of several genes encoding proteins previously implicated insporulation in Magnaporthe or in other filamentous fungi are affected byFLB3 and/or FLB4 deletion. The transcript changes associated withdeletion of FLB3 and FLB4 were also reflected phenotypically: the flb3-mutant which shows reduced transcription of several secreted lipases andincreased transcript abundance for melanin biosynthetic genes has areduced extracellular lipase activity and increased pigmentation; incontrast the flb4-mutant shows reduced transcript abundance for melaninbiosynthetic genes and is white.FUV005The interaction oft he plant-pathogen Verticilliumlongosporum and its host Brassica napus and insights into theevolutionary origin of the fungal hybrid.S. Braus-Stromeyer*, V.T. Tran, C. Timpner, C. Hoppenau, S. Singh,A. Kühn, H. Kusch, O. Valerius, G. BrausInstitut für Mikrobiologie und Genetik, Abt. Molekulare Mikrobiologie undGenetik, Göttingen, GermanyVerticillium longisporum is a soil-borne fungal pathogen of oilseed rape(Brassica napus). Infection is initiated by hyphae from germinatingmicrosclerotia which invade the plant vascular system through penetrationof the fine roots. We investigated the reaction of the fungus to xylem sapof the host-plant by differential expression of proteins related to reactiveoxygen stress [1]. Knockdowns of the catalase-peroxidase of V.longisporum were inhibited in the late phase of disease development. Theevolutionary origin of the cruciferous fungal pathogen, V. longisporum isstill a mystery. It is very closely related to both V. dahliae and V. alboatrumbut possesses some typical characteristics such as long spores,almost double amount of nuclear DNA content and cruciferous hostspecificity. V. longisporum is an example for an early stage of speciationand we show clear evidences for the origin of the fungus. To clarify thehybrid status, we undertook molecular sequence analyses of the internaltranscribed spacer (ITS) and intergenic spacer (IGS) regions of rDNA ofputative ancestors of V. longisporum. In addition a number of otherstructural genes were analyzed. We found one gene encoding a putativezinc finger transcription factor with two distinct sequences carryingdifferent markers supporting the hybrid origin detection of the fungus. Oneof these sequences is almost identical to that of V. dahliae and the other ishighly similar to the sequence of V. albo-atrum. Currently we aresequencing V. longisporum to determine which rearrangements occurredduring and after the hybridization.1. S Singh, SA Braus-Stromeyer, C Timpner, O Valerius, Av Tiedemann, P Karlovsky, C Druebert,A Polle, and GH. Braus, Molecular. Plant-Microbe Interactions, accepted (2011), DOI:10.1094/MPMI-08-11-0217FUV007The plant pathogenic fungus Heterobasidion produces planthormone-like compounds to elude the plant defenseN. Horlacher* 1 , S. Schrey 1 , J. Nachtigall 2 , R. Hampp 1 , R. Süssmuth 2 , H.-P. Fiedler 11 University Tuebingen, IMIT, Tuebingen, Germany2 TU Berlin, Institut für Chemie, Berlin, GermanyThe basidiomycete Heterobasidion annosum s.l. is a common pathogen ofconifers in the northern hemisphere and is responsible for high annuallosses in the forest industry [1] by causing the ‘annosum root rot’ [2]. H.annosum s.l. produces a variety of secondary metabolites with differentantibiotic activities e.g. fomannosin [3 and 4], fomajorin S [5] andfomannoxin [6]. H. annosum s.l. infects its host trees either via exposedwoody tissues such as wounds or by fungal growth through root-to-rootcontacts or grafts with the next tree.The plants defend themselves against the infection by the necrotrophicpathogen H. annosum s.l. [7] by activation of a jasmonic acid / ethylenedependentsignalling pathway, during which the expression of the markergene Hel (encoding a Hevein-like protein) is induced [8]. This signallingpathway can be suppressed by a prior activation of the salicylic acid (SA)-dependent signalling pathway for which the PR-1 gene (pathogenesisrelated) is a marker gene [9].We found two further compounds which are produced by Heterobasidionin liquid medium. 5-formylsalicylic acid (5-FSA) is a compound that hadpreviously only been chemically synthesized and 331HaNZ is an unknowncompound. 5-FSA and 331HaNZ are structural analogues to salicylic acid.We observed that addition of 5-FSA or 331HaNZ promotes the infectionof Norway spruce by Heterobasidion. We have also shown that 5-FSAinduces the expression of PR-1 in Arabidopsis thaliana and 5-FSA as wellas 331HaNZ repress the expression of Hel gene after fungal infection. Weassume that both compounds repress spruce resistance, resulting inenhanced infection by Heterobasidion.[1] Woodward, S.; J. Stenlid, R. Karjalainen, A. Hüttermann.Heterobasidion annosum: Biology,ecology, impact and control. CAB International, Wallingford, Oxon, UK, 1998[2] Asiegbu, F.O.; A. Adomas & J. Stenlid. Mol Plant Pathol 6: 395-409, 2005[3] Bassett, C.; R.T. Sherwood, J.A. Kepler & P.B. Hamilton. Phytopath 57: 1046-1052, 1967[4] Kepler, J.A.; M.E. Wall, J.E. Mason, C. Bassett, A.T. Mc Phail & G.A. Sim. J Am Chem Soc89: 1260-1261, 1967[5] Donnelly, D.M.X.; J. O'Reilly, J. Polonsky & G.W. Van Eijk. Tetrahedron Lett 23: 5451-5452, 1982[6] Heslin, M.; C. Stuart, M. R., Murchú, P. & D. M. X. Donnelly. Eur. J. For. Path. 13: 11-23, 1983.[7] Korhonen, K. & J. Stenlid. In: Woodward, S., J. Stenlid, R. Karjalainen, A. Hüttermann,eds.Heterobasidionannosum:Biology, ecology, impact and control. CAB International, Wallingford,Oxon, UK, 43-71, 1998[8] Hossain Md. M.; F. Sultana, M. Kubota, H. Koyama & M. Hyakumachi. Plant Cell Physiol. 48(12): 1724-1736, 2007[9] Beckers, G. J. M. & S. H. Spoel. Plant Biol. 8: 1-10, 2006FUV008Discovering host specificity candidate genes of Sporisoriumreilianum by genotyping mixed-variety offspringT. Wollenberg*, J. Donner, K. Zuther, L. Stannek, J. SchirawskiAlbrecht-von-Haller Institut, Molecular Biology of Plant-MicrobeInteraction, Goettingen, GermanySporisorium reilianumis a biotrophic plant pathogenic basidiomycete thatcauses head smut of maize and sorghum. The fungus exists in two varietieswith different host specificity. The sorghum variety (SRS) is fully virulenton sorghum. SRS infection of maize leads to weak symptoms, such asphyllody of the floral parts. The maize variety (SRZ) is fully virulent onmaize, but does not show symptoms on sorghum inflorescences. Instead,SRZ infection of sorghum leads to the formation of red spots containingphytoalexins on leaves.BIOspektrum | Tagungsband 2012