Gaylord, Margaret, authorTrivedi, Pankaj, advisorCharkowski, Amy, committee memberWallenstein, Matthew, committee member2024-05-272024-05-272024https://hdl.handle.net/10217/238402The world's population is projected to reach 9.8 billion by 2050, while the urgent threat of climate change is expected to impact crop physiology and pest dynamics. Understanding, preserving and leveraging the plant-associated microbiome can result in enhanced agroecosystem functioning and disease resistance for agricultural crops, thus improving food security. Sugar beet, an economically important sugar producer in the northern hemisphere, offers insights into plant-microbiome dynamics due to its susceptibility to pathogenic microbes and its association with disease suppressive soils. Cultural and chemical management practices of sugar beet are a persistent debate due to the potential negative effects on the essential microbiome and the emergence of resistant populations. To investigate the impact of weed control strategies on the soil microbiome, we conducted a long-term field study at two locations. Using next-generation sequencing and in vitro assays, we assessed the effects of glyphosate, a mix of selective herbicides and tillage treatments on the structure and function of the soil microbiome. Furthermore, we isolated 136 bacteria from the sugar beet agroecosystem and evaluated their antagonistic abilities against key diseases of sugar beet. Through in vitro and greenhouse assays, we identified effective microbial consortia for disease reduction. Additionally, we investigated the interactions between a single antagonistic isolate and an important fungal disease of sugar beet using transcriptomic analysis to reveal underlying mechanisms for biological control and pathogen response. This comprehensive understanding of the impact of various management strategies on the microbiome provides crucial insights for future crop management and highlights the potential for exploiting beneficial microbes to enhance disease control.born digitalmasters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Text