Protective mechanism against high light and their ecological importance

• Applicant: Dr. Patricia Müller-Moulé
• Subject Area: Plant Biochemistry and Biophysics
• Term: from 2004 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5420741

The goal of this project is to understand how plants cope with excess light. Plants are exposed to excess light on a regular basis and have evolved mechanisms to protect themselves. Important mechanisms include nonphotochemical quenching (NPQ) of photosynthesis and protection by antioxidants, such as carotenoids and ascorbate. Specific goals of my projects are the isolation of genes that are involved in photoprotection, using both the laboratory model plant Arabidopsis thaliana and the alpine plant Soldanella alpina. The ascorbate-, NPQ- and zeaxanthin-deficient Arabidopsis mutant vtc2npq1 bleaches drastically when transferred from low light to high light. I have mutagenized this mutant with a gene activation construct and will screen for suppressors of the high light-sensitivity. I also want to determine the function of the vtc2 gene. This gene has been cloned, but the encoded protein has no similarity to any proteins of known function. Lastly, I am interested in the ecological aspect of photoprotection. I therefore would like to determine the role of ascorbate in extreme environments, such as high-alpine plants. The plant Soldanella alpina has a very high ascorbate content, even after transfer to lowland growth conditions. Using a closely related Soldanella species, genes reponsible for the constitutive up-regulation of ascorbate could be identified.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Peter Westhoff