Structural Changes and Non-Photochemical Quenching of Chlorophyll a Fluorescence in Oxygenic Photosynthetic Organisms

2014 ◽  
pp. 343-371 ◽  
Author(s):  
Győző Garab
Keyword(s):  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Structural Changes ◽  
Photochemical Quenching ◽  
Photosynthetic Organisms ◽  
Non Photochemical Quenching

Photoprotective mechanisms during leaf ontogeny: cuticular development and anthocyanin deposition in two morphs of Agave striata that differ in leaf coloration

Botany ◽  
2009 ◽  
Vol 87 (12) ◽  
pp. 1186-1197 ◽  
Author(s):  
Nicolas Y. Fondom ◽  
Sergio Castro-Nava ◽  
Alfredo J. Huerta
Keyword(s):  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Xanthophyll Cycle ◽  
Photochemical Quenching ◽  
Delayed Response ◽  
Anthocyanin Content ◽  
Leaf Ontogeny ◽  
Leaf Coloration ◽  
Young Leaves ◽  
Non Photochemical Quenching

Our objectives were to test whether in Agave striata Zucc., a plant with crassulacean acid metabolism (CAM plant), leaf wax development is a delayed response to sunlight exposure following cutin development, and whether energy dissipation shifts from non-photochemical quenching to photochemical quenching during leaf ontogeny. Under field conditions, photosynthesis, cuticular development, and anthocyanin deposition were studied in two morphs of A. striata that differ in leaf coloration (green vs. red). We quantified leaf anthocyanin, wax, and cutin content, and also measured chlorophyll a fluorescence and leaf surface temperature. In addition, using three leaf reflectance indices, we measured relative chlorophyll and anthocyanin content, and also xanthophyll-cycle de-epoxidation state (xanthophyll conversion). Our results revealed that the main components of cuticle (wax and cutin) in leaves of A. striata are deposited during different developmental windows, which are similar to leaves of monocots such as grasses. Exposure to sunlight was found to be the most likely candidate to affect wax and anthocyanin deposition. Chlorophyll a fluorescence data revealed that the sunlight conditions experienced by both morphs predisposed the young leaves of the green morph and old leaves of both morphs to photoinhibition. Our results also revealed that old leaves of the red morph, which contain a reduced level of chlorophyll and anthocyanin, had additional photoprotection via xanthophyll conversion. The results presented here support the photoprotective function of leaf anthocyanins and wax accumulation during leaf ontogeny, indicating that their presence may compensate for the reduced dependence of non-photochemical quenching and the xanthophyll-cycle pigment conversion.

scholarly journals Correcting non-photochemical quenching of Saildrone chlorophyll-a fluorescence for evaluation of satellite ocean color retrievals

2020 ◽  
Vol 28 (3) ◽  
pp. 4274 ◽  
Author(s):  
Joel P. Scott ◽  
Scout Crooke ◽  
Ivona Cetinić ◽  
Carlos E. Del Castillo ◽  
Chelle L. Gentemann
Keyword(s):  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Ocean Color ◽  
Photochemical Quenching ◽  
Non Photochemical Quenching ◽  
Satellite Ocean Color

scholarly journals The role of LHCBM1 in non-photochemical quenching in Chlamydomonas reinhardtii

2022 ◽  
Author(s):  
Xin Liu ◽  
Wojciech J Nawrocki ◽  
Roberta Croce
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Protein Complexes ◽  
Ph Sensor ◽  
High Light ◽  
Photochemical Quenching ◽  
Knock Out ◽  
Photosynthetic Organisms ◽  
Pigment Protein Complexes ◽  
Non Photochemical Quenching

Non-photochemical quenching (NPQ) is the process that protects photosynthetic organisms from photodamage by dissipating the energy absorbed in excess as heat. In the model green alga Chlamydomonas reinhardtii, NPQ was abolished in the knock-out mutants of the pigment-protein complexes LHCSR3 and LHCBM1. However, while LHCSR3 was shown to be a pH sensor and switching to a quenched conformation at low pH, the role of LHCBM1 in NPQ has not been elucidated yet. In this work, we combine biochemical and physiological measurements to study short-term high light acclimation of npq5, the mutant lacking LHCBM1. We show that while in low light in the absence of this complex, the antenna size of PSII is smaller than in its presence, this effect is marginal in high light, implying that a reduction of the antenna is not responsible for the low NPQ. We also show that the mutant expresses LHCSR3 at the WT level in high light, indicating that the absence of this complex is also not the reason. Finally, NPQ remains low in the mutant even when the pH is artificially lowered to values that can switch LHCSR3 to the quenched conformation. It is concluded that both LHCSR3 and LHCBM1 need to be present for the induction of NPQ and that LHCBM1 is the interacting partner of LHCSR3. This interaction can either enhance the quenching capacity of LHCSR3 or connect this complex with the PSII supercomplex.

Shade lichens are characterized by rapid relaxation of non-photochemical quenching on transition to darkness

2021 ◽  
Vol 53 (5) ◽  
pp. 409-414
Author(s):  
Richard P. Beckett ◽  
Farida V. Minibayeva ◽  
Kwanele W. G. Mkhize
Keyword(s):  
Chlorophyll Fluorescence ◽  
Quantum Yield ◽  
Light Energy ◽  
Photochemical Quenching ◽  
Photosynthetic Organisms ◽  
Light Levels ◽  
Lower Light ◽  
Optimal Productivity ◽  
Sun And Shade ◽  
Non Photochemical Quenching

AbstractNon-photochemical quenching (NPQ) plays an important role in protecting photosynthetic organisms from photoinhibition by dissipating excess light energy as heat. However, excess NPQ can greatly reduce the quantum yield of photosynthesis at lower light levels. Recently, there has been considerable interest in understanding how plants balance NPQ to ensure optimal productivity in environments in which light levels are rapidly changing. In the present study, chlorophyll fluorescence was used to study the induction and relaxation of non-photochemical quenching (NPQ) in the dark and the induction of photosynthesis in ten species of lichens, five sampled from exposed and five sampled from shaded habitats. Here we show that the main difference between sun and shade lichens is the rate at which NPQ relaxes in the dark, rather than the speed that photosynthesis starts upon illumination. During the first two minutes in the dark, NPQ values in the five sun species declined only by an average of 2%, while by contrast, in shade species the average decline was 40%. For lichens growing in microhabitats where light levels are rapidly changing, rapid relaxation of NPQ may enable their photobionts to use the available light most efficiently.

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