Thale cress (IMAGE) University of Freiburg Caption When observing thale cress, Sjon Hartman and his collaborators found out which signaling pathways the hormone ethylene uses to switch on a molecular emergency program in plants in the event of flooding. Credit Iris Hartman / University of Freiburg Usage Restrictions Credit must be given to the creator. License CC BY 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.