Light switch in autumn leaves

Before trees lose their leaves in the winter, they offer us a bright autumnal display of reds, oranges, and yellows. This results from the decomposition of the compound that makes leaves green: chlorophyll. Among the decomposition products are yellow phyllobilins that demonstrate unusual chemical properties. These compounds, say scientists, act as four-step molecular “switches” that are triggered by light in different ways depending on the environment.
Source: ScienceDaily Headlines - Category: Science Source Type: news