Photosynthesis is a remarkable mechanism that produces chemical energy from luminous energy. This process is possible thanks to two small factories, called photosystems I and II. But for photosynthesis to occur, these two photosystems must not come into contact, to avoid short circuits which reduce photosynthetic activity. In plants, they are separated by structures, yet these don't seem to exist in the case of phytoplankton. So how are phytoplankton responsible for half of photosynthesis on earth?
By adapting different approaches of high-resolution cellular imaging applied to diatom Phaeodactylum tricornutum, the scientists were able to develop a 3D model of the photosynthetic system of diatoms. They observed the existence of micro-domains which, just like in plants, separate the two photosystems, allowing for even more efficient photosynthesis. All these results explain how diatoms produce about 20% of oxygen released daily on Earth, and why they have colonized the oceans for the last 100 million years.
The researchers are continuing to develop this 3D model of photosynthesis in diatoms, which will enable them to better understand how these single cell organisms will adapt to the consequences of climate change.
This result was the subject of a press release.