Doctoral Defence in Natural Resource Sciences
Monday, 10th June, Natalia Ramírez Carrera will defend her doctoral thesis in Natural Resource Sciences at the University of Akureyri.
The doctoral thesis is entitled: Can Lichens Serve as Hosts for Pseudomonas syringae in Icelandic Habitats? Isolation, Plant-pathogenic Traits, and Metabolomic Insights into the Role of P. syringae in Icelandic Peltigera Lichens
The thesis was prepared under the supervision of Dr. Oddur Vilhelmsson, Professor at the University of Akureyri. In addition, the doctoral committee included Dr. Margrét Auður Sigurbjörnsdóttir, Associate Professor at UNAK, Dr. Robert W. Jackson, Head of School of Biosciences at the University of Birmingham, Dr. Cindy E. Morris, Research Director, and Odile Berge, Research Scientist, both at France’s National Research Institute for Agriculture (INRAE), and Dr. Starri Heiðmarsson, Director of Northwest Iceland Nature Research Centre.
The defence will be held in English in the University’s Ceremonial Hall (Hátíðarsalur) in Akureyri at 13:00 and is open to the public.
Please confirm your attendance here
The defence will be streamed here.
The opponents are Professor Gabriele Berg, Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria and Dr. Jonathan M. Jacobs, Associate Professor, Department of Plant Pathology, Ohio State University..
Dr. Guðrún Rósa Þórsteinsdóttir, Director of the Centre for Doctoral Studies, and Dr. Brynjar Karlsson, Dean of the School of Health, Business and Natural Sciences will chair the ceremony.
About the Doctoral candidate
Born in Madrid in 1995, Natalia Ramírez followed her passion for nature by earning a bachelor's degree in Environmental Science from the Autonomous University of Madrid in 2018. She then advanced her scientific career by completing an MSc in Plant Biology and Biotechnology at the University College of Dublin. In August 2020, Natalia commenced her PhD studies in Natural Resource Sciences at the University of Akureyri, Iceland. She completed part of her studies at the University of Birmingham, UK and the National Research Institute for Agriculture, Food and the Environment (INRAE) in France. During her PhD, she actively contributed to the Environmental Council, initiating campaigns to enhance wastewater treatment in Iceland. Natalia also taught at the University of Akureyri, delivering practical teaching and lectures in different modules at the Faculty of Natural Resource Sciences. In addition, she completed a course in Arctic Microbiology at the University of Svalbard in the summer of 2023. Her doctoral research was supported by Rannís - The Icelandic Centre for Research, the University of Akureyri Research Fund, and Erasmus+.
Abstract
The PhD project explores a previously unidentified habitat for the plant pathogen Pseudomonas syringae. Recent trends in plant pathology research have shifted toward studying pathogens outside agricultural zones to enhance our understanding of crop contamination sources, lifecycle, and survival conditions. This study concentrates on the symbiotic organism lichens to investigate whether they could host P. syringae, a bacterium causing significant economic losses globally. A diverse range of lichen species was sampled from northern, eastern, and western Iceland. The results indicate that P. syringae exclusively inhabits the lichen genus Peltigera among the ten genera sampled, exhibiting a population similar to those in nearby plants.
Subsequently, the aim was to determine whether the strains found in lichens exhibit any virulence. Experiments conducted at INRAE: Research for Agriculture, Food and Environment by Natalia assessed the aggressiveness of P. syringae through two methods. The first method measured the growth of the bacterial population in planta one week after inoculation in 10 plant species, and the second observed symptoms on inoculated leaves over 14 days in 3 plant species. The results indicated that P. syringae strains isolated from lichens were as pathogenic as those isolated from epidemic crops in Europe, with exceptions noted for cucumber and barley with the epidemic strains being more aggressive.
The final phase of the project done at the University of Birmingham focused on why P. syringae was exclusively isolated from the Peltigera genus among ten sampled genera. A chemical analysis of three different lichen genera, including Peltigera, was conducted to determine if certain compounds from Peltigera could promote P. syringae presence or if some compound from non-Peltigera might inhibit the presence of the bacterium. Although some chemicals were identified as potential influences, all strains of P. syringae demonstrated the ability to grow in vitro in the presence of all the lichens tested.
The thesis can be found here.
All welcome!
