Researchers want to ‘talk’ to plants with new tool

Early lab experiments with tobacco (Nicotiana benthamiana) have demonstrated that they can activate the plant’s natural defence mechanism (immune response) using light as a stimulus (messenger). Light serves as a universal means of daily human communication, for example the signalling at traffic lights, pedestrian crossings, or the open-closed status of a shop

The method involves introducing light-sensitive proteins into cells that the researchers want to control. In this way they can start and switch off the many processes in those cells with the help of light.

Highlighter is a new tool

Their latest research published in PLOS Biology, describes a new tool called Highlighter, which uses specific light conditions to activate the expression of a target gene in plants, for example to trigger their defence mechanisms – humans ‘talking’ to plants.

The concept of humans being able to communicate with plants on a meaningful level has long captured the imagination of people. If such a capability was possible, it could revolutionise agriculture and our relationship with plants.

“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,” Dr Alexander Jones said. “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.”

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

An optogenetic tool for plants

When deployed in plants, Highlighter uses minimally invasive light signals for activation and inactivation, and is unaffected by the light-dark cycling in growth chambers.

The current Highlighter system is inactive under blue light conditions and active in the dark and under white light, green light and, mysteriously, red light conditions. Further work is planned to progress development of Highlighter, but the team has already demonstrated optogenetic control over plant immunity, pigment production and a yellow fluorescent protein, the latter at cellular resolution.

“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,” Dr Jones added. ”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.”