Researchers at the MRC Laboratory of Medical Sciences (LMS) have developed a new way to make glowing biological reporters more accurate, allowing scientists to track gene activity in living plants over days, weeks and potentially even months and years. The approach could help researchers study how plants respond to disease, pests and environmental stress, while opening the door to similar applications in animal and human disease models.
Published today in Nature Plants, the study addresses a longstanding challenge in autoluminescence imaging, a technique that enables organisms to generate their own light without the need for added chemicals or specialised laboratory equipment. The research was led by scientists working in Karen Sarkisyan's group and collaborators from Light Bio and international partner institutions.
Separating biology from background noise
Scientists often use light-producing reporter systems to monitor when genes switch on and off. However, in self-sustaining luminescent systems, light output is affected not only by gene activity but also by changes in metabolism, temperature, oxygen levels and other factors. This makes it difficult to determine whether changes in brightness truly reflect biological activity or simply shifts in the organism's physiological state.
To overcome this problem, the researchers engineered a new red-shifted version of a fungal luciferase and paired it with a green luminescent reporter. By measuring the ratio between the two colours rather than overall brightness, they created a system that remains reliable even when metabolism changes.
The approach effectively transforms autoluminescence from a qualitative indicator into a quantitative measurement tool, providing a more accurate picture of what is happening inside living organisms.
Watching plant defences in real time
The team demonstrated the technique in plants, tracking key defence and immune signalling pathways. Using the new dual-colour reporters, they were able to monitor hormone-driven responses over extended periods and detect localised immune activity around sites of infection, even when differences in metabolism caused large variations in overall brightness.
The system worked across both fungal and bacterial bioluminescence pathways, suggesting it could be adapted for a wide range of biological applications.
QUOTE
"One of the biggest limitations of self-sustained luminescence has been that the brightness of the signal depends on both gene expression and metabolism. By introducing a second colour as an internal reference, we can separate those effects and obtain a much more reliable readout of what's happening inside a living organism."
"This turns autoluminescence from a qualitative tool into a quantitative one. In practice, it means researchers can monitor molecular processes over long periods simply by taking photographs in the dark, without expensive equipment or invasive treatments."
Karen Sarkisyan, Group Head at the LMS and co-corresponding author of the study
From glowing plants to future biomedical applications
The ability to monitor biological processes continuously and non-invasively could support the development of "sentinel" plants that quantitatively report nutrient levels, environmental conditions or disease through changes in colour of their light emission. The technology may also help researchers study plant-pathogen interactions and crop health under more realistic field conditions.
While the study focused on plants, the researchers believe the underlying technology has much broader potential. Looking further ahead, the team is exploring ways to adapt similar approaches for use in animal tissues and disease models. This could eventually enable researchers to monitor hormone activity, gene regulation and disease-related processes over extended periods using simple imaging methods.
The work was highlighted by Nature Plants in an accompanying Research Briefing, which described the new ratiometric reporter system as a solution to the variability that has previously limited quantitative applications of fungal bioluminescence. Senior Editor Guillaume Tena noted that the new red-shifted luciferase provides an internal control that allows researchers to distinguish genuine biological signals from metabolic fluctuations.
Paper
Metabolically robust ratiometric autoluminescent reporters
Nature Plants (2026)
Published 23 October 2026
Read the paper in Nature Plants
