Program Book - 27th Fungal Genetics Conference

FULL POSTER SESSION ABSTRACTSinteraction and specification?264. Virulence of Fusarium circinatum on Pinus species. S. L. Slinski 1,2 , B. D. Wingfield 1 , T. R. Gordon 2 . 1) Genetics, University of Pretoria, Pretoria,Gauteng, South Africa; 2) Plant Pathology, University of California, Davis, California.Fusarium circinatum causes pitch canker, an important disease of Pinus species worldwide. Little is know of the genetic determinants of virulence in thispathogen although virulence-related genes have been identified in other Fusarium species. The purpose of this work was to assess the heritability ofvirulence in F. circinatum and to identify genomic regions associated with virulence. Virulence was altered through a series of sibling crosses pushing thepopulations towards high or low virulence. Crossing high and low virulence parents from the F 3-High and F 3-Low generations, respectively, generatedprogeny (HL-F 1) with a nearly continuous distribution of virulence phenotypes. One hundred progeny were evaluated for polymorphic markers segregatingfor virulence by AFLP-PCR. Four markers were found to have a strong association with the long lesion length phenotypes. The AFLP-PCRs containing themarkers were sequenced using Illumina HiSeq technology and the genomic regions associated with virulence were located on the F. circinatum genome.These regions are being studied to determine the changes resulting in loss of virulence.265. Understanding the remodeling of the wheat grain genome expression during infection, a gate to get new insights on the molecular cross-talkcontrolling the development of the interaction between the wheat and Fusarium graminearum.. Chetouhi Cherif 1,2 , Bonhomme Ludovic 1,2 , CambonFlorence 1,2 , Lecomte philippe 1,2 , Biron G-David 3 , Langin Thierry 1,2 . 1) INRA, UMR 1095 GDEC, F-63039 Clermont-Ferrand cedex 2, France; 2) UBP, UMR 1095GDEC, F-63100 Clermont-Ferrand, France; 3) CNRS-UBP 6023 LMGE, F-63171 Aubière, France.Despite numerous progresses in understanding the molecular plant defences against pathogens, the molecular mechanisms used by a fungal pathogento counter the plant defences and to optimize the host cell environment for fungal growth remain largely unknown. One of the main goals of our group isto better understand resistance and susceptibility mechanisms in wheat to Fusarium graminearum. This fungal pathogen represents the main causal agentof Fusarium head blight (FHB), an important worldwide disease in wheat reducing grain yield and quality. Contamination of grain by trichothecenemycotoxins produced by F. graminearum during infection is the primary causes of reduced grain quality. Until now, very little is known on the molecularcross-talk between this fungus and its host during a compatible interaction. In this study, we characterize the impact of F. graminearum infection on thewheat cellular processes and identify wheat genes, so called susceptibility genes (S-gene), required for disease development. Until now, very little is knownon the transcriptional changes induced by F. graminearum in a susceptible wheat cultivar. A whole genome expression analysis was performed on theFrench susceptible wheat cultivar Récital challenged with a pathogenic and mycotoxigen F. graminearum strain. Using a microarray analysis, we haveidentified 1,453 differentially expressed genes while proteome comparative analysis showed 80 differentially regulated proteins between healthy andFusarium-damaged kernels at different development stages of the grain (flowering at 450 °Cd). These disease-associated genes and proteins belong tothree main functional groups including (i) plant defense, (ii) primary, secondary and energy metabolism and (iii) regulation and signaling. These resultsdemonstrate that the F. graminearum infection strategy associates (i) suppression of plant defense, and (ii) subtle changes in nutrient availability relatedprocesses.These preliminary results strongly suggest that F. graminearum manipulates the functioning of wheat kernel cells to optimize its nutrition, andtherefore that the disease susceptibility of wheat relies on a parasite manipulation by this pathogenic fungi. This is the first exhaustive study of themolecular mechanisms associated with FHB development in a susceptible wheat cultivar.266. Genetic and epigenetic changes in Fusarium graminearum following serial subculture. Rhaisa Crespo 2 , Heather E. Hallen-Adams 1 . 1) Food Scienceand Technology, Univ of Nebraska-Lincoln, Lincoln, NE; 2) University of Puerto Rico, Mayaguez, Mayaguez, PR.Fusarium isolates are notably unstable in culture and given to degradation unless certain precautions are taken. After only a few rounds of serialsubculture, isolates can irreversibly lose the ability to form sporodochia, followed by conidia. The mechanism of these changes is unknown. To understandthe nature of Fusarium morphological changes in culture, we began subjecting the sequenced strain of F. graminearum to serial subculture in July, 2011.Multiple lineages were begun from an initial soil stock, and each lineage is subcultured weekly, and a sample stored under glycerol at -80 C. For this study,we have performed shotgun pyrosequencing using 454 FLX-Plus on five of the lineages from one year after the study began; we have also sequenced onelineage from the beginning of the study (when all lineages should have been identical, and not significantly different from the published F. graminearumgenome), and compared all to the published genome. Finally, we have used Illumina for bisulfite pyrosequencing to obtain methylation profiles.267. Evolutionary and functional analysis of mitosis-related kinase genes in Fusarium graminearum. Huiquan Liu 1 , Jiwen Ma 1 , Shijie Zhang 1 , DaweiZheng 1 , Juanyu Zhang 1 , Chenfang Wang 1 , Jin-Rong Xu 1,2 . 1) College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China; 2) Departmentof Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America.Eukaryotic cell cycle is a series of recurrences of a defined set of events; during which, nuclear DNA is replicated in the S phase and segregated into twodaughter nuclei during mitosis. To date, many protein kinases important for the onset and progression through mitosis have been identified. Most of thesemitosis-related kinases are thought to be conserved from yeast to humans. In the model fungi used for cell cycle studies, including Saccharomycescerevisiae, Schizosaccharomyces pombe, and Aspergillus nidulans, the single copy cdc2 (CDC28) CDK gene is a key regulator of cell cycle essential forgrowth. However, the filamentous ascomycete Fusarium graminearum, the causal agent of wheat and barley head blight disease, has two putative Cdc2orthologs. Either one of them is essential but deletion of both may be lethal. Whereas the cdc2B mutant has only minor defects in germination andgrowth, deletion of cdc2A had no obvious defects in growth but resulted in significant reductions in virulence. Ascosporogenesis but not peritheciumformation or ascogenous hyphal growth was blocked in the cdc2A mutant. Mutants deleted of the single CDK kinase gene FgCAK1 had similar phenotypeswith the cdc2A mutant. Both cdc2A and cdc2B interacted with itself and each other, and with FgCAK1. Therefore, cdc2A and cdc2B must have independentand overlapping functions in F. graminearum. It is likely that cell cycle regulation involves different cdc2 kinases and CDK activation mechanisms betweenvegetative and in plant growth. Infectious growth and ascosporogenesis may require only cdc2A, which is activated by FgCAK1. In addition, we found thatF. graminearum has two Aurora protein kinase genes that are orthologous to yeast IPL1. The two F. graminearum Aurora kinases differ at the amino acidresidue that is known to be related to different functions of Aurora A and Aurora B in humans, further indicating that yeast and F. graminearum differ insome key protein kinases involved mitosis. In addition, we systematically identified orthologs of other mitosis-related kinase genes in representative fungi.Although most of them are conserved across fungal tree of life, some mitosis-related kinase genes are lost or duplicated in certain lineages.268. Functional analysis of A MADS-box transcription Mcm1 in Fusarium graminearum . Cui Yang 1 , Guotian Li 2 , Qian Zheng 1 , Meigang Liu 1 , Jin-Rong Xu 1,2 ,Chen fang Wang 1 . 1) NWAFU-PU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shanxi, China; 2) Department ofBotany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America.186