MetaboTalks

Wheat is the largest field crop in Canada and provides essential nutrients to every day diets. However, across the Canadian prairies, a significant pest, Sitodiplosis mosellana (wheat midge), poses a threat to the production of wheat and thus food security. The threat wheat midge presents have led to efforts to understand the wheat-wheat midge relationship to reduce and prevent crop and economic losses. The oviposition mechanism of wheat midge typically involves adult wheat midge females laying eggs in late spring/early summer. Female wheat midge lay eggs usually during dusk when wind speeds are lower and temperatures are cooler. Once the eggs hatch, larvae emerge and feed on the wheat, resulting in a decrease in grain quality and quantity, demonstrating the importance of understanding the wheat-wheat midge relationship to prevent crop and economic losses. It has been observed that wheat midge has a preference for wheat in pre-anthesis as opposed to post-anthesis and for certain cultivars of wheat while actively avoiding other cultivars. It is hypothesized that wheat midge may be avoiding oviposition during post-anthesis and on certain cultivars of wheat due to the volatile organic compounds (VOCs) wheat emits. In this talk, the volatilomes of a wheat cultivar known to deter wheat midge is compared to the volatilome a wheat cultivar known to be susceptible to wheat midge. Additionally, results comparing wheat VOCs between pre- and post-anthesis will be discussed. To profile the volatilome of wheat for insights into potential plant defense mechanisms and understand wheat midge ovipostion, an in vivo active sampling system was utilized with thermal desorption (TD) tubes and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS), the ultimate untargeted analytical platform for characterizing volatile plant metabolites.