Photosynthesis is a biological process of primary importance, as it provides the energy that drives food, feedstock and biofuel production and mitigates climate change. Light in excess of photosynthetic capacity can be damaging, thus ways to protect against damage have evolved, including ways to minimize light absorption, detoxify reactive oxygen species generated by excess light, and dissipate excess absorbed light. Together, these processes are known as photoprotection.
The objective of the proposed research project is to solve molecular mechanisms of photoprotection in plants, in particular one involved during prolonged light stress such as during drought, extreme cold or high temperature combined with high light.
By increasing the efficiency by which light energy is converted into biomass we can increase the efficiency and production of food and plant-based products. The new knowledge generated by the action can be exploited to inform manipulations that aim at down regulating or eliminating sustained energy dissipation which may prove to significantly increase food or energy crops yield and or particular relevance here fiber from trees.
Expanding knowledge of photoprotection mechanisms should also enable new designs for artificial light-harvesting systems as biophysical properties from nature's design are unveiled.
The overall objectives were to determine the mechanism of qH and identify new molecular players involved in its regulation. In this project, we found that the dissipation of energy by qH can take place in the trimeric antenna of plants and may stem from chlorophyll-chlorophyll excitonic interactions. We also identified a new domain in the protein SOQ1 which negatively regulates qH. The C-terminal domain of SOQ1 has homology to nDsbD and is essential for repressing qH. Furthermore, we have used whole genome sequencing of 65 Arabidopsis mutants and found the causative mutations for their altered qH phenotype in about 20% of them. We have also studied LCNP function in inducing qH.
