Can we warn plants about danger by ‘talking’ to them?

It may be possible to “talk” to plants and warn them of impending attacks or extreme weather, new research suggests

A team of plant scientists at the Sainsbury Laboratory Cambridge University (SLCU) would like to turn this science “fiction” into reality by using light-based messaging to communicate with plants.

Early laboratory experiments with tobacco demonstrated that a plant’s natural defence mechanism (immune response) can be activated by using light as a stimulus (messenger).

Using light as a messenger, the researchers are developing tools that enable plants to communicate with humans, and humans to communicate with plants.

In everyday human life, light is used for communication such as traffic lights and pedestrian crossings.

Lead researcher Dr Alexander Jones said: “If we could warn plants of an impending disease outbreak or pest attack, plants could then activate their natural defence mechanisms to prevent widespread damage.

“We could also inform plants about approaching extreme weather events, such as heatwaves or drought, allowing them to adjust their growth patterns or conserve water.

“This could lead to more efficient and sustainable farming practices and reduce the need for chemicals.”

Previously, the Cambridge researchers engineered a series of biosensors – devices that measure biological or chemical reactions – using fluorescent light to visually communicate in real time what is happening at the cellular level in plants.

These biosensors reveal how plants react to environmental stresses – plants communicating with humans.

The new study describes a tool called Highlighter, which uses specific light conditions to activate a specific gene in plants, for example to trigger their defence mechanisms – humans talking to plants.

Bo Larsen, who engineered Highlighter while at SLCU, has taken scientists a step closer to this goal of talking to plants by engineering a light-controlled gene expression system (optogenetics system) that is tailored for plants.

Optogenetics is a scientific technique that uses a light to activate or deactivate a specific process.

“Light stimuli are cheap, reversible, non-toxic and can be delivered with high-resolution,” Dr Jones said.

According to the study, when deployed in plants Highlighter uses minimally invasive light signals for activation and inactivation.

Dr Jones said: “Highlighter is an important step forward in the development of optogenetics tools in plants and its high-resolution gene control could be applied to study a large range of fundamental plant biology questions.

“A growing toolbox for plants, with diverse optical properties, also opens exciting opportunities for crop improvement.

“For example, in the future we could use one light condition to trigger an immune response, and then a different light condition to precisely time a particular trait, such as flowering or ripening.”

The research is published in the Plos Biology journal.