AMANDA R. MEIER
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I seek to understand the mechanisms underlying interactions among microbes, plants, and insects, and consequences of such interactions for community dynamics

Chemical ecology of microbe-plant-insect interactions 
I am interested in uncovering the chemical and molecular mechanisms that underlie interactions among microbes, plants, and insects.  For my dissertation with Mark Hunter at the University of Michigan, I investigated how arbuscular mycorrhizal fungi (AMF), ubiquitous microbial symbionts of plants, influence toxin sequestration and performance of insect herbivores by altering the defensive chemistry of milkweed (Asclepias) species (Meier & Hunter 2018a). Furthermore, as plants interact simultaneously with herbivores and symbionts above and belowground, I also considered how AMF influence the herbivore-induction of plant defensive chemistry both above and belowground (Meier & Hunter 2018b). Lastly, by altering plant volatile emissions, soil microbes can alter the attraction of herbivores and their natural enemies to host plants. Therefore, I also evaluated how AMF and herbivores interact to shape volatile organic compound emissions among milkweed species (Meier & Hunter 2019). ​
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Influence of microbes on multitrophic interactions 
Most studies to date have considered only the effects of microbes on bipartite interactions between plants and insects. However, herbivore populations are known to be structured both by bottom-up forces, such as resource availability, and top-down forces, such as predators and parasitoids. Microbial symbionts, such as AMF, can alter both bottom-up forces, such as by altering plant nutrient availability and defenses, and top-down forces, by altering the attraction of natural enemies to their herbivore prey. Through field experiments, I evaluate how AMF shape the population dynamics of herbivores and their natural enemies by altering the strength of these forces (Meier & Hunter, in prep). ​
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Managing soils for natural pest control 
For my USDA-NIFA postdoctoral fellowship at the University of Georgia in the lab of Bill Snyder, I am investigating how we can manage soils to improve natural pest control. Specifically, I seek to understand (1) how common soil management practices shape microbial communities, (2) how these shifts in microbial communities alter plant resistance to herbivores and disease, and (3) whether certain management practices can enhance natural suppression of herbivores by their natural enemies. To do so, I have carried out a large field experiment, evaluating how common soil amendments (chicken manure, fish bone meal, worm castings, or a mix of all three) influence herbivore and natural enemy abundances on tomatoes in the field. Results coming soon!
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Investigating how on-farm management may promote disease suppressive soils
I have formed a network of sixty collaborating organic farmers throughout the Southeast. Through on-farm interviews and soil surveys, I am using a correlative approach to untangle how on-farm management shapes soil physicochemical properties, microbial communities (via Illumina MiSeq), and the abundance of soil-borne pathogens (via qPCR, in collaboration with Dr. Hehe Wang, Clemson University) and plant-parasitic nematodes. Results coming soon!
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  • Home
  • Research
  • Mentoring
  • Science in the Community
  • Publications & C.V.
  • Farmer Collaborators