Seedling Cells from Arabidopsis thaliana (image) American Association for the Advancement of Science Share Print E-Mail Caption Shown is a transmission electron microscopy image of seedling mesophyll cells from an Arabidopsis thaliana plastid ferrochelatase 2 (fc2) mutant. In this mutant, chloroplasts can accumulate high levels of toxic singlet oxygen, a reactive oxygen species formed during photosynthesis. In these cells, most of the chloroplasts (green organelles) and mitochondria (red organelles) appear healthy. However, the chloroplast in the top left of the image is being selectively degraded and is interacting with the central vacuole (blue). This strategy to degrade singlet oxygen-damaged chloroplasts may be to help a cell avoid any further oxidative damage during photosynthesis. Credit [Credit: Salk Institute] Usage Restrictions Please cite the owner of the material when publishing. This material may be freely used by reporters as part of news coverage, with proper attribution. Non-reporters must contact Science for permission. Share Print E-Mail 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.