Waterproof roots. 1,100 Words on Duke Research. September 10, 2018. The glowing yellow rectangles in this Arabidopsis root mark a layer of tightly packed cells that form the root’s inner skin, controlling the flow of water and nutrients into the plant from the soil. In a new study, Duke PhD Colleen Drapek of the Benfey lab identified two interacting genes that can “reprogram” other types of root cells to produce similar waterproofing in outer regions of the Arabidopsis root where they are not normally found. The findings could help researchers understand how such protective barriers in developing plant roots come to be, and eventually improve crop productivity in drought-prone or nutrient-poor soils.