Research in the Leach group focuses on understanding the molecular mechanisms of plant disease susceptibility and resistance, with a particular interest in quantitative traits for susceptibility and resistance. Leach also studies how climate changes impact plant disease caused by microbial pathogens, primarily studying rice and interactions with bacterial pathogens, and how the Russian wheat aphid microbiome influences the insects’ aggressiveness to plants. Her group also develops molecular diagnostics for microbial pathogens.