The mechanism of dynamic control of the photosynthetic light harvesting in plants

Alexander V. Ruban
Queen Mary University of London, Mile End Road, London E14NS, United Kingdom

The emergence and evolution of life on our planet was possible owing to the Sun which provides energy to our Biosphere. All life forms need energy for existence and proliferation in space and time. Light energy conversion takes place in photosynthetic organisms that evolve in various environments featuring an impressive range of light intensities that span several orders of magnitude. This property is achieved by the evolution of mechanisms of efficient light harvesting that involved development of antenna pigments and pigment-protein complexes as well as the emergence of various strategies to counteract the detrimental effects of high light intensity on the delicate photosynthetic apparatus. In this talk I will focus on the mechanisms of light harvesting and photoprotection in photosystem II. The molecular mechanism of non-photochemical chlorophyll fluorescence quenching, NPQ, its regulatory factors and significance in protection of the reaction center from the photodamage will be in the focus of this talk. The new evidence for LHCII aggregation and macrostructural reorganization of photosystem II and their role in qE will be presented. The scheme explaining how PsbS and xanthophylls may exert control over qE by controlling the affinity of LHCII complexes for protons with reference to the three major concepts of dynamic light harvesting membrane: hydrophobicity change, allostery and hysteresis (light memory) will be presented.

Reference

[1] A.V. Ruban, Plant Physiology 2016, 170, 1903-1916.