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Anamarija Butković defends her thesis on an experimental study of plant virus adaptability

  • October 13rd, 2021
Anamarija Butković - Santiago F. Elena

This doctoral thesis, supervised by Santiago F. Elena, presents a series of experimental studies on the strategies of virus evolvability and adaptation to plant hosts. The results of this research have been published in the journals Scientific Reports, Virus Evolution, PNAS, Archives of Virology and Advances in Virus Research. The thesis was defended on 13 October 2021.

Viruses are the most abundant biological entities on Earth and have a great capacity for evolution and adaptation. Some viruses are able to infect a wide range of hosts causing damage in a number of important plants while others infect one host species really well and cause severe detrimental symptoms in a short time span. With time viruses can adapt well to novel hosts and increase their infectivity, virulence and therefore provoke more damage to the host. Yet we still lack knowledge about how plants respond to viral infection with viruses that have different adaptation histories or host ranges, or how viruses that are differently adapted to the host respond to distinct environmental challenges. This thesis tried to answer these questions with an experimental system of turnip mosaic virus (TuMV) infecting the model plant Arabidopsis thaliana. Different strains of TuMV with different adaptation histories were used. Some were naïve to arabidopsis, whereas other ones were preadapted to the host with different host ranges (generalist or specialist). A method called genome-wide association studies (GWAS) was used to associate plant genes involved in viral infection with different TuMV strains. Using the GWAS method, plant genes that responded differentially to a generalist and a specialist virus were identified and characterized. Finally, arabidopsis was inoculated with the naïve and preadapted virus and their genetic robustness (the constancy of the phenotype under mutational changes) and environmental robustness (the constancy of the phenotype under environmental changes) were tested. The results show how adaptation to one environment limits evolvability in alternative ones, thus restricting the capacity of the preadapted virus to quickly respond to future environmental changes.

Anamarija Butković’s thesis was carried out in the Evolutionary Systems Virology research group at I2SysBio under the supervision of Santiago F. Elena (CSIC Research Professor). During the development of her thesis Anamarija Butković has enjoyed a contract within the Grisolia Program (Generalitat Valenciana) and an EMBO short-term fellowship during her stay at Mart Krupovic’s lab (Pasteur Institute, Paris). The examining board was formed by Carmen Hernández (IBMCP, CSIC-UPV), Jesús Israel Pagán Muñoz (UPM) and Philippe Roumagnac (The French Agricultural Research Centre for International Development CIRAD), who graded the thesis as outstanding.