Unravelling the biosynthetic pathway of sesquiterpene lactones in industrial chicory and Belgian endive using CRISPR/Cas site-specific mutagenesis (CRISPR-CICH)

Industrial chicory and Belgian endive are two traditional Belgian crops with a high economic value and which contain nutritionally-relevant components. However, the bitter taste of the chicory roots and of the Belgian endive limits their optimal use and applications. If we could reduce the bitterness of the chicory roots, they could then be processed into chicory flour for use in gluten-free cookies and healthy snacks. A more diverse assortment of Belgian endive, from not bitter to extremely bitter, would also increase the market value and acceptance for Belgian endive. The central question in this project is thus: can we modify the bitterness in chicory and Belgian endive?

At the start of this research project, breeding towards more or less bitterness in chicory and Belgian endive is done using classical selection programs, which is time consuming and results in only a narrow range of variation. Using the CRISPR/Cas9 technology, a recent innovative breeding technique, genome modifications can be induced at specific, pre-defined places in the genome. This technology is not been used in chicory and Belgian endive before, and will therefore be optimized for these crops in this project. CRISPR/Cas9 can then be used to induce specific alterations in the genes involved in the biosynthetic pathway of the sesquiterpene lactones, which are responsible for the bitterness. Using this approach, the pathway, the involved genes, and most of the components that determine bitterness will be studied in detail. This will result in much faster production of chicory and Belgian endive plants with a modified content of sesquiterpene lactones, and thus with a possibly different level of bitterness.

The production of chicory and Belgian endive has decreased in Belgium during the latest years. Modifying the bitterness will create new markets for these crops. A less bitter chicory root can be processed to flour to be used in the bakery industry (i.e., gluten-free cookies and healthy snacks). Creating a new market in the food industry will increase the production of chicory again. Being able to provide a more diverse assortment for Belgian endive, from not bitter to extremely bitter, will also increase the demand for Belgian endive. In addition, if the CRISPR/Cas9 technology works well for chicory and Belgian endive, it will open opportunities for faster breeding towards other economically interesting traits in chicory and Belgian endive as well as a range of other crops. Finally, the CRISPR/Cas9 technology offers many possibilities to gain fundamental knowledge on pathways of economically interesting traits.