Effects of high light and elevated temperature on the structure of photosystem II isolated from Arabidopsis thaliana.

High light and elevated temperature cause significant structural damage to photosystem II in Arabidopsis thaliana, including loss of subunits and photodamage near the D1 and D2 subunits.

• Why it matters: Understanding how environmental stressors damage photosystem II is crucial for improving plant resilience and photosynthetic efficiency under climate change conditions.
• What they did: Researchers exposed isolated photosystem II complexes from Arabidopsis thaliana to high light and elevated temperature, then used cryo-electron microscopy to compare structures at 2.74 Å and 2.44 Å resolutions.
• The result: High light and temperature conditions led to the loss of several subunits, damage near the non-heme iron, and movement of D1:His252, suggesting mechanisms for photodamage and potential auto-proteolysis of D1.