Dose-Dependent Genetic Resistance to Azole Fungicides Found in the Apple Scab Pathogen
The evolution of azole resistance in fungal pathogens presents a major challenge in both crop production and human health. Apple orchards across the world are faced with the emergence of azole fungicide resistance in the apple scab pathogen Venturia inaequalis. Target site point mutations observed in this fungus to date cannot fully explain the reduction in sensitivity to azole fungicides. Here, polygenic resistance to tebuconazole was studied across a population of V. inaequalis. Genotyping by sequencing allowed Quantitative Trait Loci (QTLs) mapping to identify the genetic components controlling this fungicide resistance. Dose-dependent genetic resistance was identified, with distinct genetic components contributing to fungicide resistance at different exposure levels. A QTL within linkage group seven explained 65% of the variation in the effective dose required to reduce growth by 50% (ED50). This locus was also involved in resistance at lower fungicide doses (ED10). A second QTL in linkage group one was associated with dose-dependent resistance, explaining 34% of variation at low fungicide doses (ED10), but did not contribute to resistance at higher doses (ED50 and ED90). Within QTL regions, non-synonymous mutations were observed in several ATP-Binding Cassette and Major Facilitator SuperFamily transporter genes. These findings provide insight into the mechanisms of fungicide resistance that have evolved in horticultural pathogens. Identification of resistance gene candidates supports the development of molecular diagnostics to inform management practices.
(This article belongs to the Special Issue Genomics of Fungal Plant Pathogens, 2nd Edition)
Funding
Using precision diagnostic technologies to tailor disease management strategies
Biotechnology and Biological Sciences Research Council
Find out more...History
School affiliated with
- Department of Life Sciences (Research Outputs)
Publication Title
Journal of FungiVolume
9Issue
12Pages/Article Number
1136Publisher
MDPIExternal DOI
eISSN
2309-608XDate Submitted
2023-09-14Date Accepted
2023-11-17Date of First Publication
2023-11-24Date of Final Publication
2023-11-24Relevant SDGs
- SDG 2 - Zero Hunger
- SDG 3 - Good Health and Well-being
Open Access Status
- Open Access