Glucosinolates are plant defense compounds characteristic of the economically important plant family of Brassicaceae, which comprises crops as oilseed rape, cabbage, broccoli and the model plant Arabidopsis thaliana (Arabidopsis). Recently, two Arabidopsis glucosinolate transporters, GTR1 and GTR2, were identified. In this thesis, we show that GTR1 and GTR2 are not required for obtaining the strategic margin distribution of glucosinolates in a mature Arabidopsis leaf, and we suggest a model for leaf allocation of glucosinolates. As glucosinolates are defense compounds, we asked if eliminating GTR1 and GTR2 would influence the ability of the plant to defend itself against attackers. Infecting WT and gtr1gtr2 dKO leaves with the necrotic fungus Botrytis cinerea showed an increased susceptibility of the transporter mutant compared to WT. In a second biotic interaction, we infested WT and gtr1gtr2 dKO leaves with the generalist aphid Myzus persicae. Aphids performed poorly on gtr1gtr2 dKO leaves compared to WT leaves. Translational biology defines the ability to transfer genetic and molecular knowledge obtained from laboratory model plants (e.g. Arabidopsis) to crop plants. Here we show that by eliminating a GTR ortholog in a Brassica crop, we obtain an agriculturally desired seed glucosinolate reduction.