Light is required for photosynthesis, but too much light can be harmful to algae and plants. The involvement of excited and highly reactive intermediates in oxygenic photosynthesis poses unique problems with respect to the generation of reactive oxygen species (ROS). To protect the photosynthetic apparatus from oxidative damage, algae and plants have evolved antioxidant systems that scavenge ROS, as well as mechanisms that regulate photosynthesis to minimize the production of ROS. These mechanisms are especially critical in high light, when the absorption of light energy exceeds a plant's capacity for CO2 fixation. Excess light, which is often encountered on a daily basis in nature, can result in a loss of photosynthetic efficiency (photoinhibition) and photo-oxidative damage to pigments (bleaching), proteins, lipids, and DNA.
Our long-term goal is to understand the genetic basis for ecologically relevant physiological traits. By isolating algal and plant mutants, we aim to identify important processes involved in photoprotection and photo-oxidative stress responses. A diverse set of techniques, including genetics, physiology, biochemistry, molecular biology, spectroscopy, and genomics, are used to characterize the mutants and to assess the physiological significance of different protective mechanisms. Future studies may allow us to manipulate plant productivity and the ability of plants to grow in different, often adverse, environments.
Research in the Niyogi Lab is focused on four major projects:
