Vitamins play a crucial role in all organisms and can lead to severe diseases in case of deficiency. Vitamin transport is one of the poorly defined fields in biology and several transporters are still unknown. In order to find new plant thiamin transporters, constructs containing homologs of AtPUT3 (a known thiamin transporter from Arabidopsis thaliana) were made and introduced in a specific yeast strain lacking thiamin biosynthesis and transport, called CVY4.