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ARS Home » Pacific West Area » Pullman, Washington » Grain Legume Genetics Physiology Research » Research » Publications at this Location » Publication #407270
Research Project: Developing Abiotic and Biotic Stress-Resilient Edible Legume Production Systems through Directed GxExM Research

Location: Grain Legume Genetics Physiology Research

Title: The effects of chemical fungicides and salicylic acid on the apple microbiome and fungal disease incidence under changing environmental conditions

Author
item MCLAUGHLIN, MICHAEL - Aafc Lethrdge Research Center
item Yurgel, Svetlana
item ABBASI, P - Aafc Lethrdge Research Center
item ALI, SHAWKAT - Aafc Lethrdge Research Center

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/18/2024
Publication Date: 2/5/2024
Citation: McLaughlin, M., Yurgel, S., Abbasi, P.A., Ali, S. 2024. The effects of chemical fungicides and salicylic acid on the apple microbiome and fungal disease incidence under changing environmental conditions. Frontiers in Microbiology. 15. Article 1342407. https://doi.org/10.3389/fmicb.2024.1342407.
DOI: https://doi.org/10.3389/fmicb.2024.1342407

Interpretive Summary: The communities of micro-organisms that reside on the surface or within host plants can alter their susceptibility to stressors, including infections by fungal pathogens. However, these microbial communities are highly variable, and can be influenced by changes in the environment or through the application of treatments such as chemical fungicides. In this study, we examined how chemical fungicides and plant defense elicitors influenced the fungal communities of Honeycrisp apples from a single orchard over two growing seasons. We show significant changes in communities of different tissues, in the communities of each growing season, and between the different treatments. We also show that chemical fungicides severely reduce the complexity of these communities, which in turn suggests a loss in community stability. Finally, we show that the integration of plant defense elicitors into a conventional spray program can reduce fungicide use while maintaining strong protection against fungal disease both during harvest and post-storage.

Technical Abstract: Epiphytic and Endophytic micro-organisms associated with plants form a complex communities on or within their host plant. These communities influence physiological traits, development, and host-susceptibility to abiotic and biotic stresses, and it is theorized that these communities evolved alongside their hosts, forming a unit of selection known as the ‘Holobiont’. The microbiome is highly variable and can be influenced by abiotic factors, including the application of exogenous agents. Here, we compared the impact of chemical fungicide and salicylic acid treatments on the fungal communities of ‘Honeycrisp’ apples from a single orchard over two consecutive growing years. We demonstrate variation in fungal community structure and composition between tissue-types, growing season, and treatment regimes. Furthermore, fungicide treatments were associated with reduced network complexity. Finally, the inclusion of salicylic acid with fungicides in an integrated spray program allowed for a reduction in fungicide without compromising disease control both at harvest and following storage.