Exciton migration and fluorescence quenching in LHCII aggregates: Target analysis using a simple nonlinear annihilation scheme

It was recently discovered that the main light-harvesting complex of plants, LHCII, plays a key role in the dissipation of excess energy in the process of non-photochemical quenching. Here we demonstrate that the excitation kinetics in the quenched state can be described by a simple model, which assumes specific trapping centers to be present in the system. In order to explain the experimental results a physical model for exciton-exciton annihilation is applied. Besides providing a more detailed interpretation of the kinetic data, the model provides a general annihilation scheme which can potentially be applied to a number of systems provided the pool of pigments is sufficiently large.