Dr. Block joined the Chemistry Research Unit at USDA-ARS-CMAVE in 2015 and the focus of her research is on the chemical defenses of maize (corn) against insect pests, particularly fall armyworm and corn silk flies. Maize uses a variety of chemicals to defend itself against herbivorous insects both directly by inhibiting insect growth, feeding or attraction and indirectly by attracting predators or parasites. These chemicals include volatile organic compounds, flavonoids, benzoxazinoids and phytoalexins. The Block lab uses co-expression analysis and knowledge-guided approaches to identify genes involved in the production of these chemical defenses. CRISPR/Cas9 and transposon based strategies are then used to isolate maize mutants in these genes to confirm their function and unravel the function of the chemicals they produce. Ultimately this research allows the development of molecular-breeding approaches for the production of maize lines with increased pest resistance. This in turn reduces the production and environmental costs of growing maize. The Block group also studies the impact of abiotic stresses (elevated carbon dioxide, flooding, drought and extreme temperature) on the chemical defenses of maize and the impact these combinatorial stresses have on insect resistance. These studies provide vital knowledge required for the development of breeding and management strategies that are effective in real world "multi-stress" environments.