Ion Pump in Plant (IMAGE) Linköping University Caption This is a photo and illustration of the function. The ion pump electronically deliver a common stress hormone known as ABA into a tobacco plant. Credit Thor Balkhed and Miriam Huerta Usage Restrictions In connection with news from Linkoping University 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.