The Polish scientists proved that plants remember information about light, and a certain type of cell transmits that information, much like nerves do in animals. In the study, the researchers found that light shone on one leaf of an Arabidopsis thaliana plant caused the whole plant to respond. The response lasted even after the light source was taken away, suggesting the plant remembered the light input. The scientists, thus, found that the leaves remember light quality as well as quantity. Different wavelengths of light produce a different response and the plants use the information to generate protective chemical reactions like pathogen defense or food production. As reported by the BBC on July 14, scientists found that light shining on a leaf cell triggered a cascade of events that was immediately signaled to the rest of the plant via a type of cell called a bundle sheath cell. Those cells exist in every part of a plant.

It was known to biologists that plants can remember. But they need to know whether through a cold season before they can germinate in the spring. Scientists already know plants transmit electrical signals in response to a stimulus, just as nerves do. Polish scientists said the light memory represents a new way for plants to respond to pathogens or disease -normally, they respond by direct contact with an invader.

Karpinski, a well-known plant biologist of Poland earlier found how plants respond to light stress. He also proved chemical signals can be passed throughout whole plants, allowing them to respond to and survive environmental changes. Understanding the mechanisms that cause those signals is a new step, however.

William John Lucas, a distinguished professor of plant biology at UC-Davis studied how plants pick up non-biological information, such as water and light, and how they transmit that information to the entire plant. According to him plants can’t move to a sunnier, wetter spot, so they need to make the most of their environment.