Diseased Tomato Plant (IMAGE) University of California - Berkeley Caption Signs of tomato speck on a leaf lacking a protective microbiome and subsequently invaded by a pathogenic microbe, Pseudomonas syringae. Credit Norma Morella photo, Koskella lab, UC Berkeley 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.