Plants in light.

In nature, plants have to face frequent fluctuations of intensity and spectral quality of their primary source of life-light, whose energy is needed to drive the processes of photosynthesis. A multilevel network of adaptations exists to help the plant to track and cope with fluctuations in the light environment. At the molecular level, the light harvesting antenna complex of photosystem II (LHCII), which collects the most significant part of the light energy, was found to play a central regulatory role by finely controlling the amount of energy delivered to the reaction centers. This is achieved by several mechanisms, which are summarized in this review. The fundamental features of the design of the photosynthetic antenna make photosynthetic light harvesting efficient, physiologically competent and flexible at the same time, ensuring high levels of plant survival and productivity within a wide range of light environments on our planet.