Arabidopsis (IMAGE) Howard Hughes Medical Institute Caption When exposed to pathogens, the common lab plant A. thaliana relies on a defense protein called NPR1 to stay healthy (right). Plants that lack NPR1 (left) become infected and develop yellow leaves. Credit Raul Zavaliev/Duke University Usage Restrictions Must use credit. License Original 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.