Dr. Yi-Fang Tsay‘s research is Nitrate Transport and Sensing in Higher Plants. Nitrogen is a major limiting factor for crop productivity. For most plants, nitrate is their primary nitrogen source. Nitrate taken into the plant can be assimilated right away in the root tissue, stored in the vacuole for future use, or transported to the leaf tissue and assimilated there. Characterization of nitrate transporter genes in the NRT1 (PTR) family revealed novel molecular and regulatory mechanisms for several critical steps of nitrate transport including uptake, storage, xylem loading and unloading, and remobilization.