Scientists from Vrije Universiteit Amsterdam and research institutions in China have for the first time visualized the molecular machinery behind photosynthesis directly in their natural environment within plant cells.
The results, published in the scientific journal Nature, show that these protein complexes are organized differently than previously assumed.
Photosynthesis is the process by which plants convert sunlight into chemical energy. In doing so, they produce oxygen and form the basis of virtually all life on Earth. “Although this process has been studied for decades, detailed structures could only be studied until now after the proteins had been removed from their natural environment. As a result, it remained unclear whether those images provided a realistic picture of the photosynthetic machinery at work” says Professor of Biophysics of Photosynthesis Roberta Croce.
Individual atoms visible
Using advanced cryo-electron microscopy, the researchers mapped the photosynthetic protein complexes directly within the membranes of rice chloroplasts, with a resolution that makes nearly individual atoms visible. Next, they used computer simulations to investigate how captured solar energy is channeled through these molecular structures.
The images show that the photosystems form larger assemblies in their natural environment than was previously known. In addition, the researchers discovered an unexpected molecular structure that helps shape the photosynthetic membrane. “According to our research, it is precisely this natural organization that contributes to the exceptionally efficient transfer of solar energy within plant cells,” says physicist Eduard Elias.
How photosynthesis works under natural conditions
The study thus provides the first realistic molecular image of how the machinery responsible for the photosynthetic light-to-electron conversion is organized and functions in living plant cells. This forms an important basis for future research into how photosynthesis works under natural conditions.
Photosynthesis not only provides the oxygen we breathe but also forms the basis of our food production and plays an essential role in absorbing carbon dioxide from the atmosphere. A better understanding of this process can help researchers enable crops to utilize sunlight more efficiently in the future. This can contribute to higher agricultural yields, more sustainable food production, and better preparation for the growing global demand for food.
Image: A rice field with on top thein situ structure of the complex that splits water making oxygen, which is one of the studied systems