Key to Better Photosynthesis

Photosynthesis is the process by which plants; some bacteria use the energy from sunlight to produce glucose from carbon dioxide and water. Photosynthesis is the foundation of life on Earth providing the food, oxygen and energy that sustains the biosphere and human civilization. Our scientists have found a way to solve the structure of one of the key components of photosynthesis. This discovery leads to photosynthesis to be redesigned to have higher yields and meet urgent food security needs. The study, led by the University of Sheffield and published in the journal Nature, shows the structure of cytochrome b6f -- the protein complex that significantly influences plant growth via photosynthesis. Scientist performed a study using a high-resolution structural model and found that the protein complex provides the electrical connection between the two light-powered chlorophyll-proteins (Photosystems I and II) found in the plant cell chloroplast that convert sunlight into chemical energy. Lorna Malone, the first author of the study and a PhD student in the University of Sheffield's Department of Molecular Biology and Biotechnology, said: "Our study provides important new insights into how cytochrome b6f utilizes the electrical current passing through it to power up a 'proton battery'. This stored energy can then be then used to make ATP, the energy currency of living cells. Ultimately this reaction provides the energy that plants need to turn carbon dioxide into the carbohydrates and biomass that sustain the global food chain." Also, Dr Matt Johnson who is a reader in Biochemistry at the University of Sheffield and one of the supervisors of the study further said: "Cytochrome b6f is the beating heart of photosynthesis which plays a crucial role in regulating photosynthetic efficiency. Previous studies have shown that by manipulating the levels of this complex we can grow bigger and better plants. With the new insights we have obtained from our structure we can hope to rationally redesign photosynthesis in crop plants to achieve the higher yields we urgently need to sustain a projected global population of 9-10 billion by 2050." However now the researchers are aiming to establish how cytochrome b6f is controlled by a myriad of regulatory proteins and how these regulators affect the function of this complex. This research was conducted in collaboration with the Astbury Centre for Structural Molecular Biology at the University of Leeds.

By: Anuja Arora

Content: https://www.sciencedaily.com/releases/2019/11/191113153102.htm