Plants are able to think, remember and react to information contained in light.
Plants transmit information about light intensity and quality from leaf to leaf in a very similar way to our own nervous systems.
Scientists showed that light shone on to one leaf caused the whole plant to respond and the response, in the form of light-induced chemical reactions in the leaves, continued in the dark.
The plants used the information encoded in light to stimulate protective chemical reactions. The scientists studied this by looking at the effect of different colours of light on the plants' immunity to disease.
It seems the plants perform a sort of biological light computation, using information contained in the light to immunise themselves against diseases that are prevalent during a season based on the quality of the light they 'see'.