| Abstract [eng] |
In this dissertation, excitation energy transfer in photosynthetic light-harvesting systems is studied together with the self-regulatory molecular mechanisms utilized by plants to quickly adopt to the varying environment conditions. These mechanisms, known as non-photochemical quenching, allow plants to efficiently function at both low and high illumination levels. Based on the known molecular structure of the major light-harvesting complexes (LHCII), the efficiency of different carotenoid pigments in dissipating the excess excitation energy is evaluated. Various theoretical models are formulated and developed in order to understand the processes of fluorescence intermittency and singlet–triplet annihilation, observed in single LHCII complexes. It is also demonstrated that the multi-exponential fluorescence decay kinetics, observed in various photosynthetic systems is just a manifestation of the fluctuating properties of the light-harvesting antenna and its proteins. Analysis of the time-resolved temperature-dependent fluorescence spectra of LHCII aggregates revealed several distinct intrinsic states of LHCII complexes and provided possibility to connect each state with its underlying molecular mechanism. Finally, theoretical study of the fluorescence induction kinetics revealed the dynamic macroscopic reorganization of the thylakoid membranes, happening in vivo during the short-term adaptation to the varying illumination intensity. |
