Plant Evolution (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption Berkeley Lab researchers have uncovered the unique structure of photosystem I (PSI), a key complex of proteins involved in photosynthesis, in moss, helping to shed light on how plants evolved. Credit Masakazu Iwai/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.