Protein condensate as a plant sunscreen.

Plant photosynthesis generates singlet oxygen (1O2), a powerful oxidant that can inhibit photosynthesis in return. In this issue of Cell, Shao et al. demonstrate that a small zinc-finger protein, MBS1, via 1O2-induced oxidation and consequent condensate formation on the chloroplast surface, can screen light penetration into chloroplast and confer photoprotection of plants under high light stresses.