Shoot-Derived GFP-CEPD1 Signal in Roots (IMAGE) Nagoya University Caption CEPD polypeptides are switched on in the shoots in response to nitrogen starvation in the roots. These polypeptides then descend into the roots, and activate a nitrate transporter gene. Credit Yoshikatsu Matsubayashi Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.