Salk Chory PIFs (IMAGE) Salk Institute Caption Nuclei of plant cells are seen before and after the plant was exposed to shade. In the top images (before), the transcription factor PIF7 (red) is confined in speckles that contain the plant's light sensors (green). In the lower images (after), in the shaded plant, PIF7 is released, which is then free to bind to DNA and initiate gene activity. Credit Chan Yul Yoo, Meng Chen lab, UC Riverside Usage Restrictions with credit and related coverage. 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.