Natchem-JBEI (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption A leaf with various synthetic promoters expressing Green Fluorescent Protein, demonstrating the range of expression levels that can be achieved with their engineered promoters. Credit JBEI/Berkeley Lab 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.