Light signaling in tomato plants helps protect them from damage caused by excessive sunlight. This protection is triggered by a specific type of light and involves a protein called HY5. When HY5 levels are low, the plants are more vulnerable to cold-induced damage. The protection mechanism involves the production of a reactive oxygen species called H2O2. Additionally, the plants increase their ability to protect themselves from sunlight by activating certain enzymes and electron pathways. Overall, the study shows that light signaling plays a crucial role in helping plants cope with environmental stress.