Murchie, Erik H.; Niyogi, Krishna K.

Light is of course essential for photosynthesis and supports most life on earth. However, light intensity and spectral quality are highly variable in space and time according to time of day, season, geography, climate, and the position of leaf within canopy and cell within leaf. This has resulted in the evolution of a remarkable suite of processes within the photosynthetic system to accommodate these fluctuations. In fact, these regulatory mechanisms are tightly integrated with photosynthesis itself, and there is emerging evidence that when these processes are altered, the ability of plants to assimilate carbon over long time periods and to produce biomass may be affected.