Understanding the volatile profile of flavonoid altered corn lines and its potential impacts on insect behavior
Research Poster Health & Life Sciences 2025 Graduate ExhibitionPresentation by Faith Mihalick
Exhibition Number 139
Abstract
To defend themselves from herbivores, plants have evolved a chemical toolkit that allows them to counter herbivore attack through various direct and indirect defenses. Despite this, many agricultural plants are still vulnerable to herbivores resulting in damage to crops. Rather than depending on chemical pesticides, we search for alternative avenues to improve natural protection, such as creating genetic changes in crop lines to hyper-express certain defense genes. In maize, flavonoids are polyphenolic specialized metabolites that have detrimental effects on insects that consume them, but it is unknown if altering flavonoid expression results in systemic changes to other plant defenses. To determine how altered flavonoid expression influenced plant indirect defense, we analyzed the volatile profiles of hyper expressive flavonoid line UE, a silenced flavonoid line (US), and a background wildtype, B73, after 24 hours of collection. We then identified and quantified differences in maize volatiles known to be ecologically important for natural enemy recruitment and plant-herbivore interactions. Additionally, we performed behavioral assays to investigate herbivore preferences. The differences observed in volatile profiles between treatments did not provide clear insight into the observed behavior. This highlights the complexity of interactions and consequences that arise in these altered plant systems, emphasizing the need to understand how insect behavior can be influenced. Understanding the tradeoffs that hyper-expressive lines have on plant direct and indirect defenses will allow them to be properly incorporated into agroecosystems by accounting for all their different traits and potential effects on insect communities. This project is funded by USDA-NIFA.
Importance
This study examines how plant breeding can alter plant's ability to defend themselves from different insect herbivores through changing the way they smell. This then effects how insects can recognize the plant for food resources- either eating the plant itself (herbivorous insects) or consuming the herbivore on the plant (predacious insects). How insects recognize plants through smell can change the entire insect community, and understanding how genetic regulation controls this recognition is fundamental to evaluate how different breeding lines can be used in agroecosystems to control pests.