Solid fundamental knowledge on folate (vitamin B9) metabolism in
plants is of paramount importance, given the fact that it is required to
enhance the level of this vitamin in food crops, a process known as
biofortification. Although a lot of information on plant folate
metabolism has been acquired over many years of research, some
crucial aspects remain unclear. First, no long-distance folate
transporter has been characterized in plants. Furthermore, there is
limited knowledge on folate binding and stabilizing proteins (FBPs).
To date, only one FBP from plants has been discovered, for which
substantial functional evidence is lacking. In this project, we will
perform full functional characterization of the recently discovered
FBP as well as discover new FBPs by screening for proteins with
high binding-capability to labeled folate molecules. On the other
hand, we will retrieve novel folate transporters by screening mutant
plants able to survive on antifolates, molecules strongly resembling
folates, but conferring detrimental physiological effects. In parallel,
plant genes will be scored for their folate transporting ability by
assessing their potency to recover growth in a mutated
microbiological strain, which depends on introduction of folate
transporters. In doing so, we will fill crucial gaps in the fundamental
knowledge of folate metabolism, and thereby feeding future
biofortification approaches.