Aalok Mishra

Seminar Title: Mechanisms and Fitness Consequences of Multidrug Fungicide Resistance in Plant-Pathogenic Fungi

Aalok Mishra
PhD student

About the Presenter

Aalok is currently a Ph.D. student in the Department of Plant Pathology at WSU. He pursued an MS in Agriculture, specializing in Mycology and Plant Pathology, from Banaras Hindu University, India, in 2023. His master’s research was focused on evaluating the biocontrol and plant growth-promoting potential of endophytic Trichoderma asperellum isolated from pigeon pea. After completing his master’s degree, he worked as a Molecular Lab Instructor in the National Wheat Research Program under the Nepal Agricultural Research Council (NARC), where he investigated geographic and morphological variability of Bipolaris sorokiniana isolates associated with spot blotch of wheat sampled from different parts of Nepal. His current research focuses on detection and management of Mucor spp. associated with pome fruits. In his free time, he enjoys listening to music and playing cricket.

Abstract

Fungicide resistance is an increasingly important constraint on effective management of fungal diseases of crops. Repeated use of fungicides that target a specific enzyme/protein (i.e., target-specific fungicides) imposes strong selection for fungicide resistance in pathogen populations. Resistance to fungicides can arise by mutations in fungicide-targeted proteins or via mechanisms unrelated to the fungicide target (i.e., non-target mechanisms) [1,2]. For example, fungi can develop resistance to chemically unrelated fungicide classes with distinct modes of action (multidrug fungicide resistance; MDR) due to broad-spectrum efflux pump activity [2,3]. The primary mechanisms of efflux-mediated MDR are ATP-binding cassette (ABC) and MFS (major facilitator superfamily) transporters [3,4], although MDR can also involve systemic genome-wide alterations in sugar transport, phytotoxin biosynthesis, and virulence-related pathways [4]. However, efflux-mediated resistance can result in numerous negative physiological effects, including altered gene expression levels, protein functions, active transport, and resource allocation [5]. For example, MDR Botrytis cinerea strains exhibited reduced in planta virulence due to suppression of key phytotoxin genes (Bcbot1, Bcboa2), alongside accelerated saprophytic growth driven by glucose transporter overexpression [4]. Similarly, Monilinia fructicola strains with multiple-resistant phenotypes showed severe penalties in osmotic sensitivity, sporulation, and aggressiveness, whereas the phenotype of single-fungicide resistant strains showed little detectable reduction in fitness [6]. Multiple-resistant Penicillium expansum isolates also showed reduced fitness under specific nutritional and environmental conditions, although pathogen virulence on apples during long-term storage was not affected by multiple resistance [7]. In general, fitness consequences are highly variable and depend on fungal species and genetic factors (resistance mechanism, fungal genetic background), the pathogen’s life-cycle stage, and environmental factors such as temperature, nutrient availability, oxidative and osmotic stress [2,5]. To date, numerous studies have emphasized the complexity and context-dependence of the fitness costs associated with fungicide resistance [7]. Overall, the persistence of fungicide resistance represents a balance between its selective advantage under fungicide exposure and its fitness consequences when selection is reduced. Understanding these mechanism-specific trade-offs is essential for predicting population dynamics and designing durable resistance management strategies.

Meeting Information

Mondays at 4:10 p.m. Clark Hall 151
Meeting ID: 874 8808 0602
Passcode: 3075

If you have any questions, please do not hesitate to contact Dmitri Mavrodi, instructor for PL_P 515 in Fall 2026 semester: dmavrodi@wsu.edu.

Literature Cited

1.  Yin, Y., Miao, J., Shao, W., Liu, X., Zhao, Y., and Ma, Z. 2023. Fungicide Resistance: Progress in Understanding Mechanism, Monitoring, and Management. Phytopathology 113:707–718. https://doi.org/10.1094/PHYTO-10-22-0370-KD
2. Dorigan, A. F., Moreira, S. I., Da Silva Costa Guimarães, S., Cruz-Magalhães, V., and Alves, E. 2023. Target and non-target site mechanisms of fungicide resistance and their implications for the management of crop pathogens. Pest Management Science 79:4731–4753. https://doi.org/10.1002/ps.7726
3. Hu, M., and Chen, S. 2021. Non-Target Site Mechanisms of Fungicide Resistance in Crop Pathogens: A Review. Microorganisms 9:502. https://doi.org/10.3390/microorganisms9030502
4. Sofianos, G., Piombo, E., Dubey, M., Karlsson, M., Karaoglanidis, G., and Tzelepis, G. 2024. Transcriptomic and functional analyses on a Botrytis cinerea multidrug-resistant (MDR) strain provides new insights into the potential molecular mechanisms of MDR and fitness. Molecular Plant Pathology 25:e70004. https://doi.org/10.1111/mpp.70004
5. Hawkins, N. J., and Fraaije, B. A. 2018. Fitness Penalties in the Evolution of Fungicide Resistance. Annu. Rev. Phytopathol. 56:339–360. https://doi.org/10.1146/annurev-phyto-080417-050012
6. Dutra, P. S. S., Carraro, T. A., Nesi, C. N., Amorim, L., and May De Mio, L. L. 2024. Comparative Fitness of Monilinia fructicola Isolates with Multiple Fungicide-Resistant Phenotypes. Plant Disease 108:3300–3310. https://doi.org/10.1094/PDIS-12-23-2549-RE
7. Puglisi, J. T., and Amiri, A. 2025. Context-Dependent Fitness Trade-Offs in Penicillium expansum Isolates Resistant to Multiple Postharvest Fungicides. Microorganisms 13:1846. https://doi.org/10.3390/microorganisms13081846