Old iron-sulfur-based mechanisms monitor the flow of electrons during photosynthesis,  The delicate balance of electrons flowing through the photosynthesis machine is crucial for the plant’s ability to convert sunlight into energy and ensure its survival.

Understanding the factors that regulate this balance is key for breeders who want to increase light conversion in plants to increase production. Scientists know that certain proteins are responsible for regulating gene expression in the photo system in response to disruption of photosynthetic electron flow, but how electrons feel is an unsolved question.

CSK is an old protein found in cyanobacteria and chloroplasts. More than a billion years ago, cyanobacteria lived in eukaryotic host cells and became chloroplasts of plants and algae, the researchers said. Now this mechanisms monitor the flow of electrons during photosynthesis.

When studying CSK proteins from cyanobacteria, plants, and diatoms, we found that CSK uses iron-sulfur clusters to capture electron transport, assess electron flow, and adjust the relative frequency of plant photo systems to maintain photosynthesis. protect plants from oxidative stress.

During photosynthesis, plants convert sunlight into energy through two photo systems. Photosystem I uses longwave light effectively, whereas Photosystem II especially prefers shortwave light, with both photo systems connected by plastoquinone pools. When the system is running, Photosystem II sends electrons to the plastoquinone pool while Photosystem I deletes and uses it.

However, if plants are exposed to shorter light, the electron balance can be lost. In this case, Photosystem II will send electrons to the plastoquinone pool, but Photosystem cannot retrieve it efficiently. These electrons can be trapped in plastoquinone pools and produce dangerous free radicals.

The two photo systems are like two photovoltaic cells connected in series. For optimal electron transport, they must convert light energy at the same speed. If electron transport is unbalanced, free radicals are produced which damage the plant’s photosynthesis machinery and can injure or kill plants.

Scientists have discovered that the CSC iron group acts as a magnet for these additional electrons. When the plastoquinone collection shrinks, meaning there is an excess of electrons, these electrons exit into CSK and block its kinase activity.

CSK is redox-reactive, which means it uses iron and sulfur to record the flow of electrons. As a result, the two photo systems work at the same speed during photosynthesis. The results provide information about elegant regulatory mechanisms in plant photosynthesis. It is possible, the researchers said, that this regulatory chain could one day be modified to improve the efficiency of photosynthesis in plants by increasing the ability to capture light in shady conditions.