New study will explore how photosynthesis works with lower-energy light

A £5.4m UKRI SLoLA award will fund a major five-year study into recently discovered long-wavelength forms of photosynthesis.

The study will be led by Imperial College London’s Departments of Life Sciences and Physics in collaboration with the Universities of Liverpool and Sheffield. It will focus on long-wavelength forms of photosynthesis that can perform the same chemistry as conventional systems but using less energy.

sLoLa funding support

The project is funded by a UKRI sLoLa (strategic Longer and Larger) award, a scheme that supports larger, long-term, team-based fundamental bioscience projects that push the frontiers of human knowledge.

Understanding oxygenic photosynthesis

Most oxygenic photosynthesis is powered by chlorophyll a, supplying energy to the biosphere and oxygen to the atmosphere. However, two rarer forms of photosynthesis operate at longer wavelengths: one based on chlorophyll d and the other on chlorophyll f.

Researchers will study all three systems, with a focus on the two unusual low-energy forms, aiming to understand how they perform the same chemistry using less energy and help resolve longstanding mysteries in conventional photosynthesis.

Professor Bill Rutherford from Imperial’s Department of Life Sciences said: ‘By using a combination of cryo-EM structures, spectroscopy and protein engineering on the chlorophyll f system, each far-red chlorophyll will be identified in terms of its colour (that is, its energy), and its location. This is not possible using conventional photosynthesis because the chlorophyll a molecules are essentially all the same colour.’

Professor Jenny Nelson of Imperial’s Department of Physics said: ‘Our computational approaches examine the relationship between location, colour, excitation energy transfer rates, and chemical outcomes. We provide theoretical models that can be tested with spectroscopy.’

The project will address long-standing questions in conventional photosynthesis such as how the protein tunes the colour of each chlorophyll, and how and when specific types of chlorophyll are put in place in each photosystem.

The mysterious enzymes that make chlorophyll d and chlorophyll f

In addition, the team will explore how these rare chlorophylls are synthesized. Dr. Dan Canniffe, University of Liverpool, said: 'As well as making modified far red photosystems for spectroscopy, we will also focus on the enzymes that make the long wavelength chlorophylls. The chlorophyll d synthase is a total mystery, and what we know of the chlorophyll f synthase is barely credible: it is the only enzyme known that has evolved from Photosystem II, the water splitting enzyme. We have joined forces with the Imperial and Sheffield teams to find the missing chlorophyll d synthase, and to figure out how both synthases work.’

Potential impact

While the study is fundamentally focused, it could also reveal insights with real-world applications. It could lay the groundwork for improving crop efficiency and inform future biotechnological applications, highlighting how fundamental science can address global challenges in food security and energy capture.

Research team

The project brings together experts from Imperial College London, the University of Liverpool, and the University of Sheffield. Key team members include:

• Professor Bill Rutherford – Imperial College London, Department of Life Sciences
• Dr. Andrea Fantuzzi – Imperial College London, Department of Life Sciences
• Professor Jenny Nelson – Imperial College London, Department of Physics
• Professor Peter Nixon – Imperial College London, Department of Life Sciences
• Dr James Murray – Imperial College London, Department of Life Sciences
• Professor Jasper van Thor – Imperial College London, Department of Life Sciences
• Dr. Dan Canniffe – University of Liverpool, Institute of Systems, Molecular & Integrative Biology
• Professor Jenny Clark – University of Sheffield, Department of Physics