A tiny transport protein acts as a slow-release valve for hormones that decide exactly how waterproof a plant's roots will be.

Plant roots use a substance called suberin to seal themselves off and control water intake. Two hormones named gibberellin and abscisic acid must reach specific parts of the cell to trigger this waterproofing. A newly identified transporter called NPF2.14 is the first known machine to move these hormones across internal cell membranes. Without this protein, the plant cannot properly regulate its internal hydration or nutrient levels. Farmers could eventually use this knowledge to breed crops that are more resilient to drought and floods.