Plants spend up to a third of their energy on the production of metabolites that are then exuded from the roots. These so-called root exudates act to shape the rhizosphere to the needs of the plant. For example, by modifying soil properties to be more favorable, but also by attracting and promoting the growth of certain microbes, leading to the establishment of a unique root microbiome. Some of these microbes are thought to be beneficial to the plant, whereas other can be detrimental. Root colonizing fungi are an important part of the root microbiome. Trichoderma species, for example, can benefit the plant by facilitating nutrient uptake and by attacking pathogenic fungi. Certain varieties of Fusarium species on the other hand, are pathogenic and can lead to devastating agricultural losses.
My work is focused on the signaling that occurs between lettuce and the root-colonizing fungi Trichoderma and Fusarium in the soil. I am trying to identify which molecules are present in lettuce root exudate, how the composition of this exudate changes during stress, and which molecules can elicit biological responses from the fungi. Simultaneously, I am trying to identify and characterize the receptors that the fungi use to perceive these signals.