Sustained photoprotection involves enhanced fluorescence intermittency in a subpopulation of LHCII
Year: 2026
Type: preprint
Abstract: Photoprotection against excess energy is essential for the survival of photosynthetic organisms under adverse conditions. In plants, excess energy can be dissipated as heat through non-photochemical quenching (NPQ) of chlorophyll fluorescence, involving the trimeric light-harvesting complex II (LHCII), the major antenna of photosystem II. How NPQ affects antenna proteins remains debated, especially as most studies focus on short-lived components artificially induced in vitro. Here, we characterize the effects of qH, a long-lived NPQ component, on the fluorescence properties of natively quenched LHCII. Single-molecule fluorescence measurements, combined with biochemical and biophysical ensemble approaches, reveal a larger and more quenched subpopulation of LHCII trimers exhibiting fluorescence intermittency in samples with qH compared to those without. This behavior is linked to a small conformational change that stabilizes a quenched state, enhancing photoprotection at the antenna level. These findings provide new insights into sustained NPQ and its role in regulating energy dissipation under natural light conditions. Teaser Enhancement of a quenched, blinking state in a subpopulation of LHCII trimers characterizes sustained photoprotection in plants.
Institutions: Centre National de la Recherche Scientifique, Aix-Marseille Université, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Umeå Plant Science Centre, Institut de Biosciences et Biotechnologies, Institut de Biosciences et biotechnologies d'Aix-Marseille, Umeå University, Massachusetts Institute of Technology, CEA Paris-Saclay - Etablissement de Saclay, CEA Paris-Saclay, Institut Català d'Investigació Química, Barcelona Institute of Science and Technology, Indiana University Bloomington, Indiana University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, Ministerio de Ciencia, Innovación y Universidades, Centres de Recerca de Catalunya, Infrastructures en Biologie Santé et Agronomie, Kempe Foundation, European Commission, Agence Nationale de la Recherche, Stiftelsen för Strategisk Forskning, Generalitat de Catalunya, Vetenskapsrådet, French Infrastructure for Integrated Structural Biology, Office of Science, Agencia Estatal de Investigación, Basic Energy Sciences, H2020 European Research Council, H2020 Marie Skłodowska-Curie Actions
Awards: G103507813, G1044684712, G1072458704, G1105844351, G110640233, G1175115578, G1275292511, G1281000767, G1455481585, G1544644610, G193230900, G1938719665, G1971932983, G2064873908, G210041235, G2262748287, G2390397592, G2447855386, G2462415295, G2469010403, G2526912347, G2578815869, G2601397997, G2910001697, G3005324705, G300979063, G3421857822, G34346518, G3480869486, G3546882995, ICIQ Impulse for Talented Postdoctoral Fellows, G3681454997, G4042783231, G425668148, G4460985483, Molecular mechanisms of photoprotection in plants., G4526231891, G4643134928, Molecular mechanisms of photoprotection in plants., G4890640476, G491712853, G5020660627, G5080475149, G5083316332, G5195188938, G5209569390, G5404395142, G5635532810, ICIQ Impulse for Talented Postdoctoral Fellows, G586857820, G6009780593, G624877701, Engineering Bio-Inspired Systems for the Conversion of Solar Energy to Hydrogen, G6656126374, G6839081950, G69051668, G6990982687, G7084143925, G712881263, G7240651115, G7259097847, G7434936867, G7468385506, G7500465773, G7805626310, G7863371703, Molecular Mechanisms of Photoprotection in Plants, Design av fotosyntes för framtidens matproduktion, G8389516595, BBSRC-NSF/BIO: Quantum-enhanced long-range energy capture, G8497050386, G8637226926, G8739499058
OpenAlex ID: W7204193756