|STRAVORADIS, STEPFANOS - Eastern Connecticut State University|
|LEBLANC, NICHOLAS - Oak Ridge Institute For Science And Education (ORISE)|
|MARRA, ROBERT - Connecticut Agricultural Experiment Station|
|HULVEY, JONATHAN - Eastern Connecticut State University|
Submitted to: Mycobiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2019
Publication Date: 11/23/2019
Citation: Stravoradis, S., Leblanc, N., Marra, R.E., Crouch, J., Hulvey, J.P. 2019. Widespread occurrence of a CYP51A pseudogene in Calonectria pseudonaviculata. Mycobiology. 48(1):44-50. https://doi.org/10.1080/12298093.2019.1689600.
Interpretive Summary: To reduce losses due to fungal blight diseases, growers use several fungicide products to protect boxwood. However, over time, fungi often develop immunity to one of the most effective types of fungicides, known as demethylation inhibitors (DMI), through mutations in certain genes. This research analyzes 25 isolates of boxwood blight fungi for a pseudogene called CYP51A to determine the potential for the development of fungicide resistance in the two species that cause this disease. The results of this study will inform growers of suitable fungicide treatments with respect to outbreak of boxwood blight, depending on the species involved. This work will be used by plant disease management specialists and nursery growers to prevent and control the spread of the boxwood blight disease.
Technical Abstract: Calonectria pseudonaviculata and C. henricotiae are two closely related fungal species responsible for boxwood blight disease in ornamental shrubs (Buxus spp.) in the U.S. and Europe. Previous studies have shown the latter species, which is restricted to Europe, to be less sensitive to select demethylation inhibitor (DMI) fungicides. An unpublished study has shown that isolates of C. pseudonaviculata displayed an early stop codon in one of three CYP51 paralogs known to confer resistance to fungicides, CYP51A. In this study we have analyzed the CYP51 paralogs for polymorphism in 25 genomes, representing geographically disparate populations of C. pseudonaviculata (n = 18) and C. henricotiae (n = 7), from the US, Europe, Asia, and New Zealand. The ubiquity of the CYP51A pseudogene in C. pseudonaviculata is a novel discovery for fungi and could have implications for the evolution of resistance to DMI fungicides in this invasive pathogen.