D3313: Quantifying insect gut microbial degradation of tomatine in American bird grasshopper

Microbes associated with insects have been known to assist in vital processes in their hosts. When the insects eat toxic plants, microbes have been known to break down plant defense chemicals, a phenomenon called symbiont mediated detoxification (SMD). Previous research on SMD has identified bacteria that degrade toxins in the gut of agricultural pests. Solanaceous plants, including tomato, eggplant, potato, and pepper produce plant defense chemicals like Tomatine (TOM). that help to deter herbivory. We aim to test whether gut microbes help detoxify TOM for herbivorous insects. We are measuring insect gut bacterial isolates’ abilities to degrade the toxin in culture using gas chromatography to estimate the amount of chemical degraded after 48 hours of exposure. We aim to use the bacterial isolates identified as degrading a significant amount of toxins in vivo applications. Infecting herbivorous insects such as grasshoppers and beetles with these degrading bacteria may provide further support for the presence of SMD in insects. We hypothesize that there will be isolates that are capable of degrading at least 75% of the plant toxin they are exposed to. Additionally, our future work will suggest a benefit of degrading isolates to the insect when exposed to plant toxins. This work will generate a foundational understanding of how Solanaceous plant toxins impact the gut microbiome of herbivorous insects. Ultimately, quantifying how gut microbes and plant toxins interact to influence grasshopper fitness will give us a better understanding of insect-plant relationships.