Study finds new clues to photosynthesis that may help rewire solar energy systems | Bengaluru News

Bengaluru: Researchers at the Indian Institute of Science (IISc) and California Institute of Technology (Caltech) have uncovered new insights into how plants transfer energy during photosynthesis. The findings could help design better artificial systems to capture and convert solar energy.They have solved a long-standing mystery involving the first steps of photosynthesis, the fundamental process in which plants, algae, and some bacteria trap energy from sunlight to produce oxygen and chemical energy. “The team has shown why initial electron movements that are critical for energy transfer happen across only one arm of a key protein-pigment complex. The study was published in the Proceedings of the National Academy of Sciences,” IISc said Wednesday.At the centre of this study is Photosystem-II (PSII), a protein-pigment complex in plants that plays a key role in turning sunlight into chemical energy. In PSII, two proteins — D1 and D2 — help in moving electrons, a crucial part of the energy conversion process. But for decades, scientists have wondered why D1 dominates this transfer, while D2 stays in the background.Now, researchers have found an answer. According to their study, subtle differences in the environments surrounding the pigments in D1 and D2 affect how they behave. In particular, the chlorophyll pigment in D1 has a lower energy excitation state than its counterpart in D2. This makes D1 more likely to attract and transfer electrons.“By swapping certain components like chlorophyll and pheophytin in D2, it may be possible to tweak this natural process. This opens door to engineering more efficient artificial photosynthesis systems,” said Prof Prabal K Maiti from the Centre for Condensed Matter Theory at IISc. Artificial photosynthesis aims to mimic what plants do naturally — use sunlight to convert water and carbon dioxide into fuel. Improving the underlying electron transfer processes could make future solar-to-fuel devices more practical and cost-effective.Bill Goddard, a senior scientist at Caltech, called the study “a leap forward in understanding how nature has optimised photosynthesis.” However, he also pointed out that significant challenges remain before this knowledge can be translated into real-world solar technologies.The research team believes their work could help guide the design of next-generation energy systems. “We are moving towards a future where sunlight could directly fuel sustainable processes,” said Maiti.