Formate protects photosynthetic machinery from photoinhibition

In plants, environmental adversity often leads to the formation of reactive oxygen species (ROS) because of excess light energy. We found that incubat ion of rice leaves under high light intensity together with CO2-depleted ai r seriously damaged photosynthesis; however, the application of potassium f ormate (2 mM) before the photoinhibitory treatment protected the photosynth esis of the plant from photoinhibition. Further analysis revealed that form ate protects PSII, RuBisCO, and FBPase from photoinhibition. Formate is tho ught to be involved in endogenous radical scavenging and/or in the supply o f CO2, derived from the formate, thereby reducing oxidative damage to the p hotosystems under photoinhibitory conditions.