A plant's 'energy snack': Effects of domestication on plant guttation and tritrophic interactions

Crop domestication can alter plant traits associated with tritrophic-level interactions such as plant-derived food sources for insects. One such food source is guttation, a secretion of droplets from xylem and phloem sap at the edges of leaves of some vascular plants. As a result of domestication, we hypothesized that guttation from domesticated highbush blueberries, a crop native to the northeast United States that has been domesticated for about 100 years, differs from their wild ancestors in chemical composition, which in turn affects the fitness of herbivores and their natural enemies. In a previous study, we showed that guttation from domesticated blueberry plants contains high levels of carbohydrates but also contains proteins. In this study, we compared the nutritional content of guttation from domesticated and wild blueberry plants and found that guttation from wild blueberry plants has higher concentrations of both carbohydrates and proteins than that from domesticated blueberry plants. In addition, we conducted studies to evaluate the effects of guttation from wild and domesticated blueberries on the longevity and egg load of insects from different trophic levels: an herbivore (Drosophila suzukii), a parasitic wasp (Trichopria drosophilae), and a predator (Chrysoperla carnea). We also conducted behavioral studies to compare the preference of these insects to guttation from wild and domesticated blueberries. These studies aim at elucidating the consequences of domestication on plant traits, such as guttation, and their effects on tri-trophic level interactions.