Using light to talk to plants

A UK-based team of researchers has developed a system for communicating with plants – using light.

Their “optogenetic” system, described in PLoS Biology, could be used to gauge how plants are responding to stress, and prepare them if there’s dry weather or a pest invasion ahead.

“If we could warn plants of an impending disease outbreak or pest attack, plants could activate their natural defence mechanisms to prevent widespread damage,” says co-author Dr Alexander Jones, a researcher at the University of Cambridge.

“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.”

The researchers genetically modified tobacco plants to carry a gene expression system they’ve called Highlighter. The genes come from a cyanobacteria which uses red and green light as signals to switch certain processes on or off.

This gave the plants “photoreceptors”: proteins that responded to specific light triggers.

The team has been able to make tobacco plants that alter their immune system, change their pigments and even grow a glowing yellow fluorescent protein, all by sending them light signals.

“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,” says Jones.

“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.”