
Scientists Discover a Natural "Cellular Sunscreen" in Plants. Then Use It to Boost Rice Yields by Up to 47%
A team of researchers has uncovered a previously unknown mechanism that plants use to protect themselves from too much sunlight and they've already shown it can be engineered to increase crop yields.
The Problem
When plants absorb more light than they can use for photosynthesis, chlorophyll releases a destructive reactive oxygen species called singlet oxygen (¹O₂). This damages photosystem II, the core engine of photosynthesis, ultimately reducing crop yields.
The Discovery
The team found that a protein called MBS1 acts as a fast-acting, natural sunscreen.
Here's how it works
Under strong light, ¹O₂ oxidizes two cysteine amino acids in MBS1's zinc-finger domain, causing them to release their zinc ion.
This triggers a structural change that makes MBS1 undergo liquid–liquid phase separation, forming dense protein condensates.
These condensates coat the chloroplast's outer envelope like a lotion, scattering incoming light and reducing penetration by 43.9%.
The response happens within 8 minutes and is fully reversible once the light stress ends.
The Result
The researchers created transgenic rice lines that overexpressed MBS1 and ran field trials in Hainan, China (a high-radiation region). The engineered rice showed a 40.2% and 47.1% increase in grain yield compared to wild-type rice.
MBS1 is evolutionarily conserved across plant species, meaning this protective trait could potentially be introduced into other staple crops to secure food production in regions with extreme solar radiation.
The mechanism was always there in plants. Scientists just didn't know about it until now. Once they understood it, they could enhance it for agriculture.
Read more on
https://cen.acs.org/food/agriculture/cellular-sunscreen-helps-boost-rice-yields/104/web/2026/06