Photosynthesis ‘hack’ could lead to new ways of generating renewable energy

March 22, 2023

Zhang and her colleagues were originally trying to understand why a ring-shaped molecule called a quinone is able to ‘steal’ electrons from photosynthesis. The researchers used a technique called ultrafast transient absorption spectroscopy to study how the quinones behave in photosynthetic cyanobacteria. In addition, the ability to regulate photosynthesis could mean that crops could be made more able to tolerate intense sunlight. Jenny Zhang is a David Phillips Fellow at the Yusuf Hamied Department of Chemistry, and a Fellow of Corpus Christi College, Cambridge. Tomi Baikie is a NanoFutures Fellow at the Cavendish Laboratory, and a Fellow of Lucy Cavendish College, Cambridge.

Zhang and her colleagues were originally trying to understand why a ring-shaped molecule called a quinone is able to ‘steal’ electrons from photosynthesis. Quinones are common in nature and can accept and give away electrons easily. The researchers used a technique called ultrafast transient absorption spectroscopy to study how the quinones behave in photosynthetic cyanobacteria.

“No one had properly studied how this molecule interplays with photosynthetic machinery at such an early point of photosynthesis: we thought we were just using a new technique to confirm what we already knew,” said Zhang. “Instead, we found a whole new pathway, and opened the black box of photosynthesis a bit further.”

Using ultrafast spectroscopy to watch the electrons, the researchers found that the protein scaffold where the initial chemical reactions of photosynthesis take place is ‘leaky’, allowing electrons to escape. This leakiness could help plants protect themselves from damage from bright or rapidly changing light.

“The physics of photosynthesis is seriously impressive,” said co-first author Dr Tomi Baikie, from Cambridge’s Cavendish Laboratory “Normally, we work on highly ordered materials, but observing charge transport through cells opens up remarkable opportunities for new discoveries on how nature operates.”

“Since the electrons from photosynthesis are dispersed through the whole system, that means we can access them,” said co-first author Dr Laura Wey, who did the work in the Department of Biochemistry, and is now based at the University of Turku, Finland. “The fact that we didn’t know this pathway existed is exciting because we could be able to harness it to extract more energy for renewables.”

The researchers say that being able to extract charges at an earlier point in the process of photosynthesis, could make the process more efficient when manipulating photosynthetic pathways to generate clean fuels from the Sun. In addition, the ability to regulate photosynthesis could mean that crops could be made more able to tolerate intense sunlight.

“Many scientists have tried to extract electrons from an earlier point in photosynthesis, but said it wasn’t possible because the energy is so buried in the protein scaffold,” said Zhang. “The fact that we can steal them at an earlier process is mind-blowing. At first, we thought we’d made a mistake: it took a while for us to convince ourselves that we’d done it.”

Key to the discovery was the use of ultrafast spectroscopy, which allowed the researchers to follow the flow of energy in the living photosynthetic cells on a femtosecond scale – a thousandth of a trillionth of a second.

“The use of these ultrafast methods has allowed us to understand more about the early events in photosynthesis, on which life on Earth depends,” said co-author Professor Christopher Howe from the Department of Biochemistry. 

The research was supported in part by the Engineering and Physical Sciences Research Council (EPSRC) and the Biotechnology and Biological Sciences Research Council (BBSRC), both part of UK Research and Innovation (UKRI), the Winton Programme for the Physics of Sustainability at University of Cambridge, the Cambridge Commonwealth, European & International Trust, and the European Union’s Horizon 2020 research and innovation programme. Jenny Zhang is a David Phillips Fellow at the Yusuf Hamied Department of Chemistry, and a Fellow of Corpus Christi College, Cambridge. Tomi Baikie is a NanoFutures Fellow at the Cavendish Laboratory, and a Fellow of Lucy Cavendish College, Cambridge. Laura Wey is Novo Nordisk Foundation Postdoctoral Fellow at the University of Turku.

Reference:
Baikie and Wey et al. ‘Photosynthesis re-wired on the pico-second timescale.’ Nature (2023). DOI: 10.1038/s41586-023-05763-9

The source of this news is from University of Cambridge

Popular in Research

1

May 25, 2023

New PhD course offers pathways for Indigenous knowledge holders

2

May 25, 2023

Baby’s first bites: How to introduce food allergens to infants

3

May 29, 2023

Ruusa Vuori wins the Näytös23 Award with her delicate collection

4

May 22, 2023

Mothers choosing to induce labour at 39 weeks have better health outcomes

5

May 23, 2023

Symposium explores AI's boundless promise—and potential dangers

New path facilitates campus access for students

Feb 2, 2023

Australians under increasing financial stress

Jan 2, 2023