Molecular basis of Non-Photochemical Quenching (NPQ); The Role of the Major Light-Harvesting Complex LHC II

2006 ◽  
Author(s):  
Sergiu Amarie ◽  
Andreas Dreuw ◽  
Josef Wachtveitl ◽  
Tiago Barros ◽  
Jörg Standfuss ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Light Harvesting ◽  
Photochemical Quenching ◽  
Lhc Ii ◽  
Light Harvesting Complex ◽  
Non Photochemical Quenching

scholarly journals Rapid regulation of photosynthetic light harvesting in the absence of minor antenna and reaction centre complexes

2020 ◽  
Vol 71 (12) ◽  
pp. 3626-3637 ◽  
Author(s):  
Francesco Saccon ◽  
Vasco Giovagnetti ◽  
Mahendra K Shukla ◽  
Alexander V Ruban
Keyword(s):  
Light Harvesting ◽  
Intrinsic Property ◽  
Photochemical Quenching ◽  
Reaction Centre ◽  
Lhc Ii ◽  
Light Harvesting Complex ◽  
Core Proteins ◽  
Membrane Components ◽  
Non Photochemical Quenching

Abstract Plants are subject to dramatic fluctuations in the intensity of sunlight throughout the day. When the photosynthetic machinery is exposed to high light, photons are absorbed in excess, potentially leading to oxidative damage of its delicate membrane components. A photoprotective molecular process called non-photochemical quenching (NPQ) is the fastest response carried out in the thylakoid membranes to harmlessly dissipate excess light energy. Despite having been intensely studied, the site and mechanism of this essential regulatory process are still debated. Here, we show that the main NPQ component called energy-dependent quenching (qE) is present in plants with photosynthetic membranes largely enriched in the major trimeric light-harvesting complex (LHC) II, while being deprived of all minor LHCs and most photosystem core proteins. This fast and reversible quenching depends upon thylakoid lumen acidification (ΔpH). Enhancing ΔpH amplifies the extent of the quenching and restores qE in the membranes lacking PSII subunit S protein (PsbS), whereas the carotenoid zeaxanthin modulates the kinetics and amplitude of the quenching. These findings highlight the self-regulatory properties of the photosynthetic light-harvesting membranes in vivo, where the ability to switch reversibly between the harvesting and dissipative states is an intrinsic property of the major LHCII.

scholarly journals Identification of parallel pH- and zeaxanthin-dependent quenching of excess energy in LHCSR3 in Chlamydomonas reinhardtii

2020 ◽  
Author(s):  
Julianne M. Troiano ◽  
Federico Perozeni ◽  
Raymundo Moya ◽  
Luca Zuliani ◽  
Kwangryul Baek ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Light Harvesting ◽  
Complex Stress ◽  
Excess Energy ◽  
Photochemical Quenching ◽  
Light Harvesting Complexes ◽  
Light Harvesting Complex ◽  
Non Photochemical Quenching

AbstractUnder high light conditions, oxygenic photosynthetic organisms avoid photodamage by thermally dissipating excess absorbed energy, which is called non-photochemical quenching (NPQ). In green algae, a chlorophyll and carotenoid-binding protein, light-harvesting complex stress-related (LHCSR3), detects excess energy via pH and serves as a quenching site. However, the mechanisms by which LHCSR3 functions have not been determined. Using a combined in vivo and in vitro approach, we identify two parallel yet distinct quenching processes, individually controlled by pH and carotenoid composition, and their likely molecular origin within LHCSR3 from Chlamydomonas reinhardtii. The pH-controlled quenching is removed within a mutant LHCSR3 that lacks the protonable residues responsible for sensing pH. Constitutive quenching in zeaxanthin-enriched systems demonstrates zeaxanthin-controlled quenching, which may be shared with other light-harvesting complexes. We show that both quenching processes prevent the formation of damaging reactive oxygen species, and thus provide distinct timescales and mechanisms of protection in a changing environment.

scholarly journals Identification of pH-sensing Sites in the Light Harvesting Complex Stress-related 3 Protein Essential for Triggering Non-photochemical Quenching inChlamydomonas reinhardtii

2016 ◽  
Vol 291 (14) ◽  
pp. 7334-7346 ◽  
Author(s):  
Matteo Ballottari ◽  
Thuy B. Truong ◽  
Eleonora De Re ◽  
Erika Erickson ◽  
Giulio R. Stella ◽  
...  
Keyword(s):  
Light Harvesting ◽  
Complex Stress ◽  
Photochemical Quenching ◽  
Ph Sensing ◽  
Light Harvesting Complex ◽  
Non Photochemical Quenching

The evolution of the photoprotective antenna proteins in oxygenic photosynthetic eukaryotes

2018 ◽  
Vol 46 (5) ◽  
pp. 1263-1277 ◽  
Author(s):  
Vasco Giovagnetti ◽  
Alexander V. Ruban
Keyword(s):  
Vascular Plants ◽  
Light Harvesting ◽  
Current Knowledge ◽  
Complex Stress ◽  
Photochemical Quenching ◽  
Light Harvesting Complex ◽  
Photosynthetic Organisms ◽  
Photosynthetic Eukaryotes ◽  
Non Photochemical Quenching ◽  
Energy Dependent

Photosynthetic organisms require rapid and reversible down-regulation of light harvesting to avoid photodamage. Response to unpredictable light fluctuations is achieved by inducing energy-dependent quenching, qE, which is the major component of the process known as non-photochemical quenching (NPQ) of chlorophyll fluorescence. qE is controlled by the operation of the xanthophyll cycle and accumulation of specific types of proteins, upon thylakoid lumen acidification. The protein cofactors so far identified to modulate qE in photosynthetic eukaryotes are the photosystem II subunit S (PsbS) and light-harvesting complex stress-related (LHCSR/LHCX) proteins. A transition from LHCSR- to PsbS-dependent qE took place during the evolution of the Viridiplantae (also known as ‘green lineage’ organisms), such as green algae, mosses and vascular plants. Multiple studies showed that LHCSR and PsbS proteins have distinct functions in the mechanism of qE. LHCX(-like) proteins are closely related to LHCSR proteins and found in ‘red lineage’ organisms that contain secondary red plastids, such as diatoms. Although LHCX proteins appear to control qE in diatoms, their role in the mechanism remains poorly understood. Here, we present the current knowledge on the functions and evolution of these crucial proteins, which evolved in photosynthetic eukaryotes to optimise light harvesting.

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