Prof Weston leads a large research team with a focus on plant interactions and chemical ecology. Research emphasis includes the generation of a deeper understanding of the plant rhizosphere and its associated microbiome, and how plant interactions with weeds, herbivores, and pests as well as biocontrol organisms are mediated by secondary products. Prof Weston also explores soil health and microbial diversity within the plant rhizosphere and the role of soil microbes and pathogens generating bioactive molecules in pest management and terrestrial ecology.

Research interests have included development of a fundamental understanding of the soil microbiome and microorganisms regulating soil cycling and chemical interactions in the soil. She also studies localization, biosynthesis, and regulation of secondary plant products including those in root exudates as sources of novel chemistry.

Applied research has focused on large multidisciplinary research projects for the use of dung beetles to improve soil fertility and livestock health, the prevention of herbicide resistance in common pasture and crop weeds and the development of alternative management strategies for weeds and livestock pests. Prof Weston also studies soil health, soil carbon capture through root exudation, and soil pathogens including entomopathogens with activity as potential biocontrol agents.

In May 2023, Leslie was elected as a Fellow of the Australian Academy of Science.