The role of the xanthophyll cycle and of lutein in photoprotection of photosystem II

Abstract

Photoprotection of photosystem II (PSII) is essential to avoid the light-induced damage of the photosynthetic apparatus due to the formation of reactive oxygen species (=photo-oxidative stress) under excess light. Carotenoids are known to play a crucial role in these processes based on their property to deactivate triplet chlorophyll (³Chl*) and singlet oxygen (¹O₂*). Xanthophylls are further assumed to be involved either directly or indirectly in the non-photochemical quenching (NPQ) of excess light energy in the antenna of PSII. This review gives an overview on recent progress in the understanding of the photoprotective role of the xanthophylls zeaxanthin (which is formed in the light in the so-called xanthophyll cycle) and lutein with emphasis on the NPQ processes associated with PSII of higher plants. The current knowledge supports the view that the photoprotective role of Lut is predominantly restricted to its function in the deactivation of ³Chl*, while zeaxanthin is the major player in the deactivation of excited singlet Chl (¹Chl*) and thus in NPQ (non-photochemical quenching). Additionally, zeaxanthin serves important functions as an antioxidant in the lipid phase of the membrane and is likely to act as a key component in the memory of the chloroplast with respect to preceding photo-oxidative stress. This article is part of a Special Issue entitled: Photosystem II.

Saline stress enhanced accumulation of leaf phenolics in honeysuckle ( Lonicera japonica Thunb.) without induction of oxidative stress

“…3b). The declined ETR was a positive response, which probably resulted from elevated dissipation of excess excitation energy by photoprotective mechanisms such as xanthophyll cycle (Brestic et al, 2015(Brestic et al, , 2016Jahns and Holzwarth, 2012). Therefore, oxidative damage was prevented by limiting ROS production in the leaves of honeysuckle under NaCl stress in the hydroponic experiments.…”

Photoprotective Non-photochemical Quenching Does Not Prevent Kleptoplasts From Net Photoinactivation

“…In green algae and land plants, the XC is based on the light-dependent conversion of the pigment violaxanthin to zeaxanthin, in red algae and stramenopiles on the light dependent conversion of diadinoxanthin to diatoxanthin (Demmig-Adams and Adams, 1996;Jahns and Holzwarth, 2012;Goss and Lepetit, 2015), and q E on the dissociation of antennae complexes from the PSII (Goss and Lepetit, 2015). Both mechanisms are generally widespread throughout algae and plants, yet some members of the Bryopsidales (Ulvophyceae) are XC and q E deficient Handrich et al, 2017).…”

“…Among the main photoprotection mechanisms are the xanthophyll cycle (XC) and the high-energy quenching (q E ) component of the non-photochemical quenching (NPQ) (Jahns and Holzwarth, 2012;Goss and Lepetit, 2015). In green algae and land plants, the XC is based on the light-dependent conversion of the pigment violaxanthin to zeaxanthin, in red algae and stramenopiles on the light dependent conversion of diadinoxanthin to diatoxanthin (Demmig-Adams and Adams, 1996;Jahns and Holzwarth, 2012;Goss and Lepetit, 2015), and q E on the dissociation of antennae complexes from the PSII (Goss and Lepetit, 2015).…”

Low-pH induced reversible reorganizations of chloroplast thylakoid membranes — As revealed by small-angle neutron scattering

“…It is generally agreed that NPQ requires the structural flexibility of thylakoid membranes. In fact, there are several reports demonstrating the involvement of structural changes at different levels of structural complexity [4][5][6][7][8][9][10][11][12][13][14]. Some of these changes might be directly linked to the generation of ∆pH, e.g., via the redistribution of ions in the 'electrolyte' following the generation of ∆µ H + [15,16] and, in particular, upon the acidification of lumen and the binding of protons to different polypeptide residues [2,17,18].…”