NCCC207 (North Central Coordinating Committee)

NCCC-207 “Biochemistry and Genetics of Plant-Fungal Interactions” Asilomar Conference Center March 20th, 2011

Meeting Minutes

Itinerary: 1:15 - 1:30 - Jeff Rollins, Chair NCCC207 Opening remarks and introductions 1:30 -2:00 - Speaker 1-Yasuyuki Kubo 2:00 - 3:00 -Speaker 2-Richard Todd 3:00 - 3:30 - Speaker 3-Maria C. Giraldo 3:30 - 4:30 Open panel discussions 4:30 - 5:00 NCCC207 business discussion

List of speakers: 1. Yasuyuki Kubo Colletotrichum orbiculare Fam1p, a pex22 like peroxin unique to filamentous ascomycete fungi, is required for pathogenesis and translocates to Woronin bodies Ayumu Sakaguchi1, Naoki Fujihara1, Gento Tsuji1, Ulla Neumann 2, Richard O’Connell 2 and Yasuyuki Kubo1 1 Kyoto Prefectural University, Kyoto, Japan 2 Max Planck Institute for Plant Breeding Research, Köln,Germany

Colletotrichum orbiculare is an anthracnose fungus which infects cucurbitaceae group. So far, several factors involved in infection related morphogenesis have been identified in C. orbiculare. Signal transduction pathway, such as cAMP dependent pathway and MAP kinase pathway are essential for germination, appressorium development, infection hyphae formation and invasive growth. And melanin biosynthesis pathway is essential for appressorium function and structural and regulatory genes involved in this pathway were identified. Peroxisome function has been elucidated as an essential factor for pathogenesis. We identified a novel protein specific to filamentous ascomycete, Fam1 that is essential for peroxisome function and associates with Woronin bodies (WB). Fam1p contains a predicted Pex4p-binding site of Saccharomyces cerevisiae Pex22p, which functions for recycling PTS receptors from peroxisomes to the cytosol and the FAM1 gene complemented the defect in peroxisomal matrix protein import in the pex22 mutants. The fam1 disruptants were unable to grow on fatty acid medium. GFPs carrying the peroxisomal targeting signals were not imported into peroxisomes of fam1 mutants. Accordingly, fam1 mutants were defective in both appressorium melanization and host penetration. The Fam1p-GFP fusion protein localized to the apical region of hyphae. This resembled the distribution of Woronin bodies (WBs), peroxisome-derived organelles involved in septal pore plugging. The WB structural protein Cohex1p-mRFP1 and WB sorting complex membrane protein Cowsc1p- mRFP fusions co-localized with Fam1p-GFP in WBs. Furthermore, the apical and septum localization of Fam1p was lost in cohex1 mutants. These results indicate that Fam1p is a novel WB-associated peroxin involving PTS receptor recycling and raise the possibility that filamentous ascomycete coordinate peroxisome function via WBs.

2. Richard B. Todd Controls of the Aspergillus nidulans nitrogen transcription factor AreA. Department of Plant Pathology, Kansas State University.

The expression of nitrogen metabolic genes in Aspergillus nidulans is controlled by the GATA transcription factor AreA. AreA activity is highly regulated by nutrient quality and availability. Modulation of AreA activity results in low levels of AreA- dependent expression of nitrogen utilization genes in the presence of ammonium, elevated levels in the presence of a poor nitrogen source and further elevated levels during nitrogen starvation. Furthermore, AreA accumulates in the nucleus during nitrogen starvation but not in the presence of a nitrogen source. We have constructed a battery of gene-replaced HA epitope-tagged areA variants to analyze AreA at the protein and subcellular levels. I will provide an update of our studies of the molecular mechanisms regulating AreA nuclear accumulation and activity, including signals for nuclear import and controls of nuclear export, and the molecular mechanism of action of NmrA, the transcriptional corepressor of AreA activity.

3. Maria C. Giraldo Spatial localization of protein secretion machinery components in Magnaporthe oryzae biotrophic invasive hyphae Martha C. Giraldo1, Yasin Dagdas2, Nicholas J. Talbot2 and Barbara Valent1

1Dept. of Plant Pathology, Kansas State University, Manhattan, KS, USA. 2School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, U.K.

To cause disease, the rice blast fungus undergoes a dimorphic switch between the filamentous invasive hyphae (IH) that first grow inside rice cells and bulbous IH that subsequently colonize them. Secreted effector proteins accumulate in the biotrophic interfacial complex (BIC), which forms at the tip of each filamentous IH and remains beside the first differentiated bulbous IH cell. FRAP analysis (fluorescence recovery after photobleaching) demonstrated that effectors continue to accumulate in BICs as the bulbous IH proliferate in the rice cells. We have localized fluorescent fusions of the Spitzenkörper-associated proteins MoMlc1p (myosin regulatory light chain) and MoSnc1p (a v-SNARE) and the polarisome-associated MoSpa2p during IH invasion of rice cells. Localization of both Spitzenkörper and polarisome markers in the filamentous IH initially resembles localization patterns in M. oryzae vegetative hyphae in vitro. After differentiation to bulbous IH, the Spitzenkörper is not, however, observed at hyphal growth points. Instead, a Spitzenkörper-like structure was observed as an intense fluorescent spot in the first bulbous IH cell, generally near to the BIC. The polarisome marker MoSpa2p shows a spatially distinct localization pattern from MoMlc1p and MoSnc1p in the bulbous IH. These results provide the first evidence that BIC-associated bulbous IH cells are undergoing active exocytosis, consistent with a role for BICs in the delivery of effectors during rice tissue invasion.

Meeting Summary: The meeting was attended by 24 scientist including a distinguished professor from Japan, a new Plant Pathology university faculty, Professors from various Universities throughout USA, and collectively 11 research scientists, post-docs and graduate students. This forum allowed individuals from several diverse disciplines and fungal systems to interact, share information, discuss collaborations and fostered an interactive environment for students and mentors alike. Discussions about future meetings met with unanimous agreement that future meetings (as an ad-hoc workshop format) will be held in concurrence with the Fungal Genetics Meeting held bi-annually at the Asilomar Conference Center. The next annual meeting will be held in March 2012 in Texas A&M, College Station, Texas, and hosted by Marty Dickman. Comments by the participants indicated that the meeting was interactive and the platform such that allowed for easy engagement of discussions. Name Institution E-mail University of 1. Regina Redman Washington [email protected] Oregon State 2. Lynda Ciuffetti University [email protected] Texas A&M 3. Marty Dickman University [email protected] 4. Adolphe Oliver Texas A&M Bush University [email protected] U.S. Geological Survey, University of [email protected], 5. Rusty Rodriguez Washington [email protected] University of 6. Lisa Vaillancourt Kentucky [email protected] University of 7. Wilfried Jonkers Minnesota [email protected] USDA-ARS Cereal Disease 8. Karen Hilburn Lab [email protected] Kansas State 9. Richard Todd University [email protected] Kansas State 10. Damien Downes University [email protected] Michigan State 11. Frances Trial University [email protected] Kansas State 12. Mihwa Yi University [email protected] 13. Chang Hyun Kansas State Khang University [email protected] Oregon State 14. Jenny Lorang University [email protected] USDA-ARS , North Dakota 15. Tim Friesen State University [email protected] North Dakota 16. Zhaohui Liu State University [email protected] University of 17. Jeff Rollins Florida [email protected] Oregon State 18. Tom Wolpert University [email protected] Ohio State 19. Tom Mitchell University [email protected] USDA, Univerity 20. Corby Kistler of Minnesota [email protected] University of 21. Nancy Keller Wisconsin [email protected] Kansas State 22. Barbara Valent University [email protected] 23. Martha C. Kansas State Giraldo University [email protected] Kyoto Prefectural University,