Program Book - 27th Fungal Genetics Conference

FULL POSTER SESSION ABSTRACTSinvolved in cellulase induction by this disaccharide. The deletion of the other 13 transporter encoding genes led to no reduction of growth on anycarbohydrate (including glucose and cellobiose), probably due to redundancy of their function. Our data show that lactose leads not only to the formationof a complete cellulase and hemicellulase system in T. reesei, but also to the transcription of a plethora of transporters likely associated with the uptake ofthe hydrolysis products.62. The diversity of the Mannosylerythritol lipids depends on the peroxisomal targeting of the Mannosylerythritol acyl transferases Mac1 and Mac2 inUstilago maydis. Johannes Freitag 1 , Julia Ast 1 , Uwe Linne 2 , Elisa Leisge 1 , Michael Bölker 1 , Björn Sandrock 1 . 1) Biology - Genetics, Philipps-UniversityMarburg, Marburg, Germany; 2) Chemistry, Philipps-University Marburg, Marburg, Germany.Under nitrogen starvation the smut fungus Ustilago maydis produces a bunch of secondary metabolites. Among these are the glycolipids Ustilagic acid(UA) and Mannosylerythritol lipid (MEL), which consist of a sugar moiety esterified with fatty acid side chains of variable length (from C2 - C18). Thebiosynthesis of UA is encoded by the UA gene cluster (11 genes). MEL production depends on the MEL gene cluster composed of the genes mat1, mmf1,mac1, emt1 and mac2. Deletion of mac1, mac2 or emt1 in U. maydis resulted in the complete loss of MELs. Medium-length fatty acids (C4-C14) are derivedfrom longer fatty acids (C16-C18) by partial peroxisomal b-oxidation. After bioinformatic analysis we have identified bona fide peroxisomal targetingsequences 1 (PTS1) at the C-termini of the two Mannosylerythritol lipid acyltransferases Mac1 and Mac2 but not in any other protein involved in thebiosynthesis of the MELs or the UAs. Here we show that Mac1 and Mac2 localize in peroxisomes, and that this localization depends on the PTS1 motifs.The analysis of glycolipid production by thin layer chromatography and mass spectrometry from wild type strain MB215 revealed a mixture of MELs withdifferent length of the fatty acid side chains ranging from C12, C14 and C16. Strains expressing both cytoplasmic variants Mac1DPTS and Mac2DPTSshowed a reduction of diversity of MELs. In these mutants MELs with C16 and C2 side chains are significantly overrepresented. This indicates that MELproduction is coupled to peroxisomal b-oxidation resulting in a more variable distribution in the length of fatty acid side chains. Currently, we investigatethe MEL production is strains lacking peroxisomes and the importance of MEL diversity for the life of U. maydis.63. Metabolic adaptation of the oomycete Phytophthora infestans during colonization of plants and tubers. Carol E. Davis, Howard S. Judelson. PlantPathology and Microbiology, University of California, Riverside, CA 92521.Phytophthora infestans is the causative agent of late blight and was responsible for the Irish famine in the 1840’s. Today it still continues to be a globalproblem and in the USA it has been reported that the economic loss on potato crops alone exceeds $6 billion per year. A successful phytopathogenicrelationship depends on the ability of the organism to adapt its metabolism during infection on various nutritional substrates (e.g., plant versus tuber) andat different times throughout infection when nutrients may be limiting. Investigation of this metabolic adaptation is key to understanding how P. infestanssucceeds as a pathogen. To do this, tomato plants and potato tubers were infected with zoospores using a “dipping” method. RNA was extracted at 3 dpiand 6 dpi and subsequently used in library preparation. Following this, the libraries were quality checked by analysis on a Bioanalyzer using a highsensitivity DNA chip. Using Illumina technology (50 bp, paired-end reads) RNA Sequencing was performed. For each sample an average of 262 million readswas obtained. As a reference for the in planta data, RNASeq was also performed on defined and complex media. Mining of the data shows that theexpression profiles of some pathways change, such as glycolysis and gluconeogenesis. Learning how metabolic adaptation occurs will prove useful in thedevelopment of novel control strategies for this plant pathogen.64. Multi-copper oxidase genes of Heterobasidion irregulare. Ming-Chen Hsieh, Bastian Doernte, Ursula Kües. Molecular Wood Biotechnology andTechnical Mycology, University of Goettingen, Goettingen, Germany.The species complex Heterobasidion consists of well-known wood decomposers that infect mainly conifers. The fungi are white rots that decay lignin andcellulose. Laccases are enzymes that potentially attack the lignin. In the sequenced genome of the North American species H. irregulare 18 multi-copperoxidase genes (mco) are found (1). Phylogenetic sequence analysis divides the encoded proteins into five subclusters of mcos. In total, 14 proteinsclustered in two different subfamilies of classical laccases whereas two others are found amongst ferroxidases/laccases (enzymes with often dualactivities), one under fungal Fet3-type ferroxidases and one with fungal ascorbate oxidases. The potential three-dimensional structures of all mcos werepredicted by homology modelling for further grouping. Six of the potential laccase genes were first chosen for subcloning and expression in theheterologous basidiomycete Coprinopsis cinerea. (1) Olson et al. (2012). Insight into trade-off between wood decay and parasitism from the genome of afungal forest pathogen. New Phytologist 194: 1001-1013.65. The two novel class II hydrophobins of Trichoderma stimulate enzymatic hydrolysis of polyethylene terephthalate (PET). Liliana E. Tenorio-Rammer 1 ,Doris Ribitsch 1 , Annemarie Marold 1 , Katrin Greimel 1 , Enrique Herrero Acero 1 , Georg M. Guebitz 1,2 , Christian Kubicek 1,3 , Irina S. Druzhinina 1,3 . 1) ACIB -Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria; 2) c/o Institute for Environmental Biotechnology, University of NaturalResources and Life Sciences, Vienna, Konrad Lorenz Strasse 20, 3430 Tulln, Austria; 3) Microbiology Group, Institute of Chemical Engineering, ViennaUniversity of technology, Vienna, Austria.Polyethylene terephthalate (PET), a thermoplastic polyester with excellent industrial properties, can be functionalised and/or recycled via hydrolysis bymicrobial cutinases. Here we tested whether hydrophobins (HFBs), small secreted fungal proteins containing eight positionally conserved cysteineresidues, would be able to enhance the rate of enzymatic hydrolysis of PET. To this end, we selected the genus of the mycoparasitic filamentous fungusTrichoderma as it has been previously shown to have the most proliferated arsenal of HFBs among all fungi. Consequently we used the phylogeneticapproach to identify the two novel class II HFBs (HFB4 and HFB7) from Trichoderma as the first candidates for the test. HFB4 and HFB7, produced in E. colias N-terminal glutathione-S-transferase fusion proteins, exhibited subtle structural differences reflected in the hydropathy plots which were correlatedwith unequal hydrophobicity and hydrophily respectively determined by water contact angle measurements. However they exhibited a dosage-dependentstimulation of PET hydrolysis by cutinase from Humicola insolens with HFB4 displaying an adsorption isotherm, whereas HFB7 was active only at very lowconcentrations and behaved inhibitory beyond them. We conclude that class II HFBs can stimulate the activity of cutinases on PET, but individual HFBs candisplay different properties in this process thus warranting a broader screening of HFBs for such industrial applications.27th Fungal Genetics Conference | 137