CPS Workshop - The increasing issue of ergot in cereal production and the biological questions being explored

Date
20/10/2021

CPS Workshop – The increasing issue of ergot in cereal production and the biological questions being explored.

Date: Wednesday, October 20, 2021 | 9:30 AM – 12:15 PM CST – Online

AGENDA

All times are in Central Standard Time (CST)

9:30 – 10:00 AM – “A Status Update on Ergot in Canada”, by Sheryl Tittlemier & Sean Walkowiak (CGC)

10:00 – 10:30 AM – “Transcriptome analysis of the wheat-Claviceps interaction from both perspectives”, by Anna Gordon (NIAB, UK), Eleni Tente, Nelzo Ereful, Lesley Boyd.

10:30 – 10:45 AM – Break

10:45 – 11:15 AM – “The 168-year taxonomy of Claviceps in the light of variations: From three morphological species to four sections based on multigene phylogenies”, by Miao Liu (AAFC).

11:15 – 11:45 AM – “Evolutionary insights into patterns of speciation and host range adaptation in the genus Claviceps and implications for disease management”, by Kirk Broders (USDA)

11:45 AM – 12:15 PM – Q&A

Abstracts:

1) A Status Update on Ergot in Canada

Sheryl Tittlemier, Sean Walkowiak, Grain Research Laboratory, Canadian Grain Commission, 303 Main Street, Winnipeg, Manitoba, Canada

Ergot is a fungal disease that occurs on cereals and grasses (i.e. rye, triticale, wheat, and barley) that infects the floret and appears as darkly coloured fungal bodies, called sclerotia. Ergot is a grading factor in Canada and can impact grade and grain quality. The Canadian Grain Commission performs an annual Harvest Survey, which captures information on a wide-array of grading factors, including ergot. Harvest Survey data provide insights into: 1) ergot frequency and severity in different grains, 2) ergot frequency and severity in different growing locations, and 3) ergot frequency and severity amongst years in Canada. One of the primary concerns regarding ergot is the presence of harmful mycotoxins – ergot alkaloids – in ergot sclerotia that that can pose food and feed safety risks. Our analyses indicate the presence of diverse ergot alkaloids in sclerotia that can persist through grain processing and appear in milling and food products. The regulation of these toxins and establishment of maximum limits is important to maintain food and feed safety, but can impact international trade.

2) Transcriptome analysis of the wheat-Claviceps interaction from both perspectives.

Anna Gordon, Eleni Tente, Nelzo Ereful, Lesley Boyd. NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE.
Anna.gordon@niab.com

We took an RNA-Seq approach to look at the interactions in three parts of the female wheat flower over a 7-day period, to build a temporal picture of the plant’s perception, response and eventual surrender to fungal take-over. Indeed, resistance mechanisms are triggered within 24h of the conidia germinating on a wheat stigma hair, along with other tantalising plant hormone responses, hinting at routes of fungal pathogenicity. Comparative RNA-seq results from UK-hexaploid wheat and Canadian-durum wheat will be presented.

3) The 168-year taxonomy of Claviceps in the light of variations: From three morphological species to four sections based on multigene phylogenies.

M. LIU. Ottawa Research and Development Centre (ORDC), Agriculture and Agri-Food Canada, 960 Carling Ave. Ottawa. ON K1A 0C6. Canada

Ergot fungi were classified in various genera (such as Sclerotium clavus, Spermoedia clavus etc.) before Tulasne (1853) erected the genus Claviceps and described three species based on variations in morphology and host ranges, viz. C. purpurea, C. microcephala, and C. nigricans. Since then, the knowledge on biological, clinical, and pharmaceutical perspectives has accumulated rapidly. However, a serious taxonomic examination was lacking until Longdon (1954)’s revision accepted 25 species. That was followed by intensive regional studies by Loveless (1960s) in England, Tanda in Japan (1970s – 1990s) and others. More species names were reported, and currently over 90 named taxa (species, varieties) are recorded in fungal name repositories (Mycobank, Index Fungorum). Most species were described utilizing morphological characteristics (sclerotia, ascomata and conidia) and host ranges. Some were characterized by alkaloid profiles. Recently, DNA multi-gene sequence analyses (MLSA) were applied to revolve species complexes. For instance, the C. purpurea complex was separated into four species, and an additional four new species were recognized in Canada. The infra- and supra-specific level genetic variations were revealed through multi-gene and genomic studies. Based on five-locus phylogenies, Pichova and colleagues separated Claviceps into four sections: C. sect. Claviceps, C. sect. Citrinae, C. sect. Paspalorum, and C. sect. pusilla, for 60 species. Among them, a number of doubtful species names are in need of clarification. Careful research on type specimens and together with molecular analyses is essential.

4) Evolutionary insights into patterns of speciation and host range adaptation in the genus Claviceps and implications for disease management

Kirk Broders USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, 1815 N, University Street, Peoria, Illinois, 61604, USA

We used comparative and population genomics to identify potential mechanisms driving speciation in the genus Claviceps, with a focus on understanding the adaptative ability of species in C. purpurea sensu latu. This presentation will summarize our findings from the both the comparative genomics of the genus Claviceps and the pangenome of C. purpurea and how this corresponds to host range and ecological niche adaptation by these different species. We will finish by linking these results to the role of alternate hosts in recent outbreaks of ergot in the isolated growing region of the San Luis Valley in Colorado.

SPEAKER BIOGRAPHIES

Dr. Sheryl Tittlemier Grain Research Lab, Canadian Grain Commission

• Received BSc at University of Manitoba and PhD in environmental analytical chemistry from Carleton University, Ottawa, Canada.
• Has been working in the area of analytical chemistry and food safety since 2002.
• Research Scientist and Program Manager for the Trace Organics Trace Elements program in the Grain Research Laboratory with Canadian Grain Commission since 2010.
• Her program is responsible for research on the factors that affect mycotoxin, pesticide, and trace element/heavy metal occurrence in grain, including fate of these contaminants during processing, and methods of analysis, including sampling best practices
• Is a member of the expert roster of the Joint (FAO/WHO) Expert Committee on Food Additives
• Co-chairs the Food Safety and Microbiology Technical Committee of the Cereals & Grains Association
• On the editorial boards for World Mycotoxin Journal and Mycotoxin Research

Dr. Sean Walkowiak, Grain Research Lab, Canadian Grain Commission

Dr. Sean Walkowiak, Canadian Grain Commission, Government of Canada, is a Research Scientist and Program Manager for Microbiology and Grain Genomics since 2019. Dr. Walkowiak is also an Adjunct Professor at the University of Manitoba in the Department of Plant Science. Sean’s research laboratory is located at the Richardson Centre for Functional Foods and Nutraceuticals at the University of Manitoba, is certified for level 2 human and plant pathogens, and is equipped with the latest tools in microbiology, genetics, and genomics. A main focus of his research includes annual microbial surveys of bacteria and fungi on Canadian grain. Sean’s research program works directly with the Canadian Grain Commission’s Harvest Survey Program, and provides detailed information on the microbes impacting Canadian grain and food safety. Sean has over ten years of experience performing applied research on grains and their diseases and his research has been published in top-ranked journals including Science, Nature, Nature Genetics, and PNAS.

Dr. Anna Gordon, NIAB

Dr. Anna Gordon is a plant pathologist at the National Institute of Agricultural Botany in Cambridge UK where she has worked for the last 15 years in wheat fungal interactions. Dr Gordon studied Biochemistry with Molecular Biology at the University of Leeds UK, and completed her PhD registered at the University of Birmingham while working as a technician at HRI Wellesbourne. Here she cloned the RPP1 resistance gene from Arabidopsis thaliana that recognised avirulence products from Hyaloperonospora parasitica. Anna became a post-doctoral scientist at the University of Manchester before coming to NIAB. She has helped develop the wheat-ergot interactions work there looking for resistance to ergot and more recently the transcriptome analysis. A year ago she became the facilities lab manager for NIAB but still maintains a love for Claviceps.

Dr. Miao (Mindy) Liu, AAFC

Dr. Miao Liu (Mindy) is a Research Scientist with the Biodiversity and Bio-Resource group at Ottawa Research and Development Centre, Agriculture & Agri-Food Canada. She graduated with a B.Sc. and a Master degree of Plant Protection and Biological Control from Beijing Forestry University (1990), and received her doctoral degree in Mycology from Department of Plant Pathology, Cornell University, New York (2005). Thereafter, she worked as a postdoctoral researcher in several institutes including: University of Kentucky; Eastern Cereal and Oilseed Research Center (current name: Ottawa Research and Development Centre), Agriculture and Agri-Food Canada; Cereal Disease Laboratory, Agriculture Research Service, U. S. Department of Agriculture, St. Paul. Her research interests include taxonomy, phylogenetics, molecular diagnostics, population evolution and genomics of plant related fungi. Currently, her research is focusing on powdery mildews (Erysiphales), ergot fungi (Claviceps) and grass endophytes (Epichloë). She is serving as the representative of Eastern Ontario region for the Canadian Phytopathological Society, and the senior editor for taxonomy section of Canadian Journal of Plant Pathology.

Dr. Kirk Broders, USDA-ARS

Dr. Kirk Broders is a microbiologist and the Curator of the USDA-ARS Culture Collection (NRRL) at the National Center for Agricultural Utilization Research in Peoria, Illinois. He received his BSc. in Biology from the University of Nebraska-Lincoln and his PhD in Plant Pathology from The Ohio State University where he studied the ecology and epidemiology of soilborne pathogens of corn and soybean. Dr. Broders completed a post-doctoral research position at the University of Guelph from 2009-2010 where he studied the population genetics and ecology of invasive plant pathogens. Dr. Broders was a faculty member at the University of New Hampshire from 2010-2014 and Colorado State University from 2014-2018 where his research focused on the ecology, evolution and epidemiology of plant pathogens in both forested and agricultural ecosystems. It was at CSU that Dr. Broders began his research on ergot of barley and other grass species in the San Luis Valley of southcentral Colorado.

Date subject to change

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