Light Acclimation in Plants: Photoinhibition and Photoprotection

Plants use light energy as one of the substrate for carrying out the process of photosynthesis, evolving O2 so sustaining life on the planet. When light energy exceeds limits that plants can use for photosynthesis it results in the production of reactive oxygen species (ROS) which damage biomolecules including photosynthetic apparatus causing light induced photoinhibition. As plants are sessile, they have developed unique mechanisms to adjust with varied light intensities. Light is absorbed by chlorophyll molecules with the help of light harvesting chlorophyll binding proteins (LHCPs) present in pigments-protein complexes of photosysten II and photosysten I. In this review emphasis has given on how plants adjust to changing light conditions by inducing changes in dynamic components of photosystems and dissipation of excess light absorbed as heat known as non-photochemical quenching (NPQ).