Researchers at the Johannes Kepler University Linz, together with British colleagues, have disproved an old theorem of biochemistry.
Their discovery in the field of photosynthesis could mean a long-term breakthrough towards higher agricultural yields.
A large part of life on our planet is made possible by photosynthesis. This chemical process allows plants to convert sunlight into energy. Until now, it was assumed that this process is only possible if the light has a wavelength of no more than 700 nanometers. Beyond that, the light waves would be too low in energy.
An international research collaboration between Imperial College in London (UK) and the JKU has now disproved this. Certain cyanobacteria are able to survive under exclusively long-wave (750 nm) light. "The limit can therefore be crossed," emphasizes Thomas Renger.
The researchers from both universities were able to show that a special long-wavelength pigment (chlorophyll f) at the beginning of the electron transfer chain plays a central role in the conversion of light energy into chemical energy. This leads to the conclusion that "Light with a wavelength longer than 750 nanometers can also support the conversion process," says the JKU physicist.
This is not a purely theoretical discovery:"Our finding disproves the old theorem of biochemistry that plants or bacteria cannot use ’red light beyond 700 nm’ for oxygen-generating photosynthesis," explains co-author Michael Hofer.
Quantum physics calculations confirmed
The discovery was made in close collaboration with researchers Bill Rutherford and Jenny Nelson at Imperial College London. High-precision electron diffraction experiments were carried out there, while Renger and his doctoral student Michael Hofer at the JKU analyzed the optical signatures of chlorophyll f using quantum physics calculations. Both methods independently led to the same result: the pigment is actually located at a central place in the reaction center of the so-called photosystem I.
Implications for agriculture The discovery could have far-reaching consequences. "If we succeed in incorporating such ’red-light chlorophylls’ into crop plants in the long term, they could use more sunlight for energy conversion," hopes Renger - and thus even significantly increase agricultural yields.
https://www.science.org/doi/10.1126/science.ado6830
