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Veljović Jovanović S, Kasalica B, Miletić K, Vidović M, Šušić N, Jeremić D, Belča I. Red-Light Transmittance Changes in Variegated Pelargonium zonale-Diurnal Variation in Chloroplast Movement and Photosystem II Efficiency. Int J Mol Sci 2023; 24:14265. [PMID: 37762566 PMCID: PMC10532150 DOI: 10.3390/ijms241814265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/18/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
Chloroplast movement rapidly ameliorates the effects of suboptimal light intensity by accumulating along the periclinal cell walls, as well as the effects of excess light by shifting to the anticlinal cell walls. These acclimation responses are triggered by phototropins located at the plasma membrane and chloroplast envelope. Here, we used a recently developed non-invasive system sensitive to very small changes in red light leaf transmittance to perform long-term continuous measurements of dark-light transitions. As a model system, we used variegated Pelargonium zonale leaves containing green sectors (GS) with fully developed chloroplasts and achlorophyllous, white sectors (WS) with undifferentiated plastids, and higher phototropin expression levels. We observed biphasic changes in the red-light transmittance and oscillations triggered by medium intensities of white light, described by a transient peak preceded by a constant decrease in transmittance level. A slight change in red-light transmittance was recorded even in WS. Furthermore, the chloroplast position at lower light intensities affected the rapid light curves, while high light intensity decreased saturated electron transport, maximum quantum efficiency of photosystem II, and increased non-photochemical quenching of chlorophyll fluorescence and epidermal flavonoids. Our results extend the knowledge of light-dependent chloroplast movements and thus contribute to a better understanding of their role in regulating photosynthesis under fluctuating light conditions.
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Affiliation(s)
| | - Bećko Kasalica
- Faculty of Physics, University of Belgrade, 11001 Belgrade, Serbia; (B.K.); (K.M.); (I.B.)
| | - Katarina Miletić
- Faculty of Physics, University of Belgrade, 11001 Belgrade, Serbia; (B.K.); (K.M.); (I.B.)
| | - Marija Vidović
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, 11042 Belgrade, Serbia;
| | - Nikola Šušić
- Institute for Multidisciplinary Research, University of Belgrade, 11030 Belgrade, Serbia;
| | - Dejan Jeremić
- Innovation Center of the Faculty of Chemistry, University of Belgrade, 11001 Belgrade, Serbia;
| | - Ivan Belča
- Faculty of Physics, University of Belgrade, 11001 Belgrade, Serbia; (B.K.); (K.M.); (I.B.)
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Lysenko V, D. Rajput V, Kumar Singh R, Guo Y, Kosolapov A, Usova E, Varduny T, Chalenko E, Yadronova O, Dmitriev P, Zaruba T. Chlorophyll fluorometry in evaluating photosynthetic performance: key limitations, possibilities, perspectives and alternatives. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2022; 28:2041-2056. [PMID: 36573148 PMCID: PMC9789293 DOI: 10.1007/s12298-022-01263-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/25/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Non-destructive methods for the assessment of photosynthetic parameters of plants are widely applied to evaluate rapidly the photosynthetic performance, plant health, and shifts in plant productivity induced by environmental and cultivation conditions. Most of these methods are based on measurements of chlorophyll fluorescence kinetics, particularly on pulse modulation (PAM) fluorometry. In this paper, fluorescence methods are critically discussed in regard to some their possibilities and limitations inherent to vascular plants and microalgae. Attention is paid to the potential errors related to the underestimation of thylakoidal cyclic electron transport and anoxygenic photosynthesis. PAM-methods are also observed considering the color-addressed measurements. Photoacoustic methods are discussed as an alternative and supplement to fluorometry. Novel Fourier modifications of PAM-fluorometry and photoacoustics are noted as tools allowing simultaneous application of a dual or multi frequency measuring light for one sample.
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Affiliation(s)
- Vladimir Lysenko
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Vishnu D. Rajput
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Rupesh Kumar Singh
- Centre of Molecular and Environmental Biology, Department of Biology, Campus of Gualtar, University of Minho, Braga, Portugal
| | - Ya Guo
- School of IoT Engineering, Jiangnan University, Wuxi, China
| | - Alexey Kosolapov
- Russian Research Institute for the Integrated Use and Protection of Water Resources, Rostov-on-Don, Russia
| | - Elena Usova
- Russian Research Institute for the Integrated Use and Protection of Water Resources, Rostov-on-Don, Russia
| | - Tatyana Varduny
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Elizaveta Chalenko
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Olga Yadronova
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Pavel Dmitriev
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
| | - Tatyana Zaruba
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia
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3
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Łabuz J, Sztatelman O, Hermanowicz P. Molecular insights into the phototropin control of chloroplast movements. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6034-6051. [PMID: 35781490 DOI: 10.1093/jxb/erac271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Chloroplast movements are controlled by ultraviolet/blue light through phototropins. In Arabidopsis thaliana, chloroplast accumulation at low light intensities and chloroplast avoidance at high light intensities are observed. These responses are controlled by two homologous photoreceptors, the phototropins phot1 and phot2. Whereas chloroplast accumulation is triggered by both phototropins in a partially redundant manner, sustained chloroplast avoidance is elicited only by phot2. Phot1 is able to trigger only a small, transient chloroplast avoidance, followed by the accumulation phase. The source of this functional difference is not fully understood at either the photoreceptor or the signalling pathway levels. In this article, we review current understanding of phototropin functioning and try to dissect the differences that result in signalling to elicit two distinct chloroplast responses. First, we focus on phototropin structure and photochemical and biochemical activity. Next, we analyse phototropin expression and localization patterns. We also summarize known photoreceptor systems controlling chloroplast movements. Finally, we focus on the role of environmental stimuli in controlling phototropin activity. All these aspects impact the signalling to trigger chloroplast movements and raise outstanding questions about the mechanism involved.
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Affiliation(s)
- Justyna Łabuz
- Laboratory of Photobiology, Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa, Kraków, Poland
| | - Olga Sztatelman
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego, Warszawa, Poland
| | - Paweł Hermanowicz
- Laboratory of Photobiology, Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa, Kraków, Poland
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4
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Schansker G. Determining photosynthetic control, a probe for the balance between electron transport and Calvin-Benson cycle activity, with the DUAL-KLAS-NIR. PHOTOSYNTHESIS RESEARCH 2022; 153:191-204. [PMID: 35844008 DOI: 10.1007/s11120-022-00934-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Photosynthetic Control is defined as the control imposed on photosynthetic electron transport by the lumen-pH-sensitive re-oxidation of plastoquinol (PQH2) by cytochrome b6f. Photosynthetic Control leads at higher actinic light intensities to an electron transport chain with a (relatively) reduced photosystem (PS) II and PQ pool and a (relatively) oxidized PS I. Making Light Curves of more than 33 plant species with the recently introduced DUAL-KLAS-NIR (Chl a fluorescence + the redox states of plastocyanin (PC), P700, and ferredoxin (Fd)) the light intensity-dependent induction of Photosynthetic Control was probed and characterized. It was observed that PC became completely oxidized at light intensities ≤ 400 µmol photons m-2 s-1 (at lower light intensities in shade than in sun leaves). The relationship between qP and P700(red) was used to determine the extent of Photosynthetic Control. Instead of measuring the whole Light Curve, it was shown that a single moderate light intensity can be used to characterize the status of a leaf relative to that of other leaves. It was further found that in some shade-acclimated leaves Fd becomes again more oxidized at high light intensities indicating that electron transfer from the PQ pool to P700 cannot keep up with the outflow of electrons on the acceptor side of PS I. It was observed as well that for NPQ-induction a lower light intensity (less acidified lumen) was needed than for the induction of Photosynthetic Control. The measurements were also used to make a comparison between the parameters qP and qL, a comparison suggesting that qP was the more relevant parameter.
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Affiliation(s)
- Gert Schansker
- Heinz Walz GmbH, Eichenring 6, 91090, Effeltrich, Germany.
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5
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Quero G, Bonnecarrère V, Simondi S, Santos J, Fernández S, Gutierrez L, Garaycochea S, Borsani O. Genetic architecture of photosynthesis energy partitioning as revealed by a genome-wide association approach. PHOTOSYNTHESIS RESEARCH 2021; 150:97-115. [PMID: 32072456 DOI: 10.1007/s11120-020-00721-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 02/10/2020] [Indexed: 06/10/2023]
Abstract
The photosynthesis process is determined by the intensity level and spectral quality of the light; therefore, leaves need to adapt to a changing environment. The incident energy absorbed can exceed the sink capability of the photosystems, and, in this context, photoinhibition may occur in both photosystem II (PSII) and photosystem I (PSI). Quantum yield parameters analyses reveal how the energy is managed. These parameters are genotype-dependent, and this genotypic variability is a good opportunity to apply mapping association strategies to identify genomic regions associated with photosynthesis energy partitioning. An experimental and mathematical approach is proposed for the determination of an index which estimates the energy per photon flux for each spectral bandwidth (Δλ) of the light incident (QI index). Based on the QI, the spectral quality of the plant growth, environmental lighting, and the actinic light of PAM were quantitatively very similar which allowed an accurate phenotyping strategy of a rice population. A total of 143 genomic single regions associated with at least one trait of chlorophyll fluorescence were identified. Moreover, chromosome 5 gathers most of these regions indicating the importance of this chromosome in the genetic regulation of the photochemistry process. Through a GWAS strategy, 32 genes of rice genome associated with the main parameters of the photochemistry process of photosynthesis in rice were identified. Association between light-harvesting complexes and the potential quantum yield of PSII, as well as the relationship between coding regions for PSI-linked proteins in energy distribution during the photochemical process of photosynthesis is analyzed.
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Affiliation(s)
- Gastón Quero
- Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Garzón 809, Montevideo, Uruguay.
| | - Victoria Bonnecarrère
- Unidad de Biotecnología, Estación Experimental Wilson Ferreira Aldunate, Instituto Nacional de Investigación Agropecuaria (INIA), Ruta 48, Km 10, Rincón del Colorado, 90200, Canelones, Uruguay
| | - Sebastián Simondi
- Área de Matemática, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (FCEN-UNCuyo), Padre Contreras 1300, Mendoza, Argentina
| | - Jorge Santos
- Área de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (FCEN-UNCuyo), Padre Contreras 1300, Mendoza, Argentina
| | - Sebastián Fernández
- Facultad de Ingeniería, Instituto de Ingeniería Eléctrica, Universidad de La República, Julio Herrera y Reissig 565, Montevideo, Uruguay
| | - Lucía Gutierrez
- Department of Agronomy, University of Wisconsin-Madison, 1575 Linden Dr., Madison, WI, 53706, USA
- Departamento de Biometría, Estadística y Cómputos, Facultad de Agronomía, Universidad de la República, Garzón 780, Montevideo, Uruguay
| | - Silvia Garaycochea
- Unidad de Biotecnología, Estación Experimental Wilson Ferreira Aldunate, Instituto Nacional de Investigación Agropecuaria (INIA), Ruta 48, Km 10, Rincón del Colorado, 90200, Canelones, Uruguay
| | - Omar Borsani
- Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Garzón 809, Montevideo, Uruguay
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Pfündel EE. Simultaneously measuring pulse-amplitude-modulated (PAM) chlorophyll fluorescence of leaves at wavelengths shorter and longer than 700 nm. PHOTOSYNTHESIS RESEARCH 2021; 147:345-358. [PMID: 33528756 DOI: 10.1007/s11120-021-00821-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
PAM fluorescence of leaves of cherry laurel (Prunus laurocerasus L.) was measured simultaneously in the spectral range below 700 nm (sw) and above 700 nm (lw). A high-sensitivity photodiode was employed to measure the low intensities of sw fluorescence. Photosystem II (PSII) performance was analyzed by the saturation pulse method during a light response curve with subsequent dark phase. The sw fluorescence was more variable, resulting in higher PSII photochemical yields compared to lw fluorescence. The variations between sw and lw data were explained by different levels of photosystem I (PSI) fluorescence: the contribution of PSI fluorescence to minimum fluorescence (F0) was calculated to be 14% at sw wavelengths and 45% at lw wavelengths. With the results obtained, the validity of an earlier method for the quantification of PSI fluorescence (Genty et al. in Photosynth Res 26:133-139, 1990, https://doi.org/10.1007/BF00047085 ) was reconsidered. After subtracting PSI fluorescence from all fluorescence levels, the maximum PSII photochemical yield (FV/FM) in the sw range was 0.862 and it was 0.883 in the lw range. The lower FV/FM at sw wavelengths was suggested to arise from inactive PSII reaction centers in the outermost leaf layers. Polyphasic fluorescence transients (OJIP or OI1I2P kinetics) were recorded simultaneously at sw and lw wavelengths: the slowest phase of the kinetics (IP or I2P) corresponded to 11% and 13% of total variable sw and lw fluorescence, respectively. The idea that this difference is due to variable PSI fluorescence is critically discussed. Potential future applications of simultaneously recording fluorescence in two spectral windows include studies of PSI non-photochemical quenching and state I-state II transitions, as well as measuring the fluorescence from pH-sensitive dyes simultaneously with chlorophyll fluorescence.
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7
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Rusaczonek A, Czarnocka W, Willems P, Sujkowska-Rybkowska M, Van Breusegem F, Karpiński S. Phototropin 1 and 2 Influence Photosynthesis, UV-C Induced Photooxidative Stress Responses, and Cell Death. Cells 2021; 10:cells10020200. [PMID: 33498294 PMCID: PMC7909289 DOI: 10.3390/cells10020200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/10/2021] [Accepted: 01/16/2021] [Indexed: 12/26/2022] Open
Abstract
Phototropins are plasma membrane-associated photoreceptors of blue light and UV-A/B radiation. The Arabidopsis thaliana genome encodes two phototropins, PHOT1 and PHOT2, that mediate phototropism, chloroplast positioning, and stomatal opening. They are well characterized in terms of photomorphogenetic processes, but so far, little was known about their involvement in photosynthesis, oxidative stress responses, and cell death. By analyzing phot1, phot2 single, and phot1phot2 double mutants, we demonstrated that both phototropins influence the photochemical and non-photochemical reactions, photosynthetic pigments composition, stomata conductance, and water-use efficiency. After oxidative stress caused by UV-C treatment, phot1 and phot2 single and double mutants showed a significantly reduced accumulation of H2O2 and more efficient photosynthetic electron transport compared to the wild type. However, all phot mutants exhibited higher levels of cell death four days after UV-C treatment, as well as deregulated gene expression. Taken together, our results reveal that on the one hand, both phot1 and phot2 contribute to the inhibition of UV-C-induced foliar cell death, but on the other hand, they also contribute to the maintenance of foliar H2O2 levels and optimal intensity of photochemical reactions and non-photochemical quenching after an exposure to UV-C stress. Our data indicate a novel role for phototropins in the condition-dependent optimization of photosynthesis, growth, and water-use efficiency as well as oxidative stress and cell death response after UV-C exposure.
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Affiliation(s)
- Anna Rusaczonek
- Department of Botany, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland; (W.C.); (M.S.-R.)
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
- Correspondence: (A.R.); (S.K.)
| | - Weronika Czarnocka
- Department of Botany, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland; (W.C.); (M.S.-R.)
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
| | - Patrick Willems
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Ghent, Belgium; (P.W.); (F.V.B.)
- VIB Center of Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium
| | - Marzena Sujkowska-Rybkowska
- Department of Botany, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland; (W.C.); (M.S.-R.)
| | - Frank Van Breusegem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Ghent, Belgium; (P.W.); (F.V.B.)
- VIB Center of Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium
| | - Stanisław Karpiński
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
- Correspondence: (A.R.); (S.K.)
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8
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Ptushenko OS, Ptushenko VV, Solovchenko AE. Spectrum of Light as a Determinant of Plant Functioning: A Historical Perspective. Life (Basel) 2020; 10:E25. [PMID: 32192016 PMCID: PMC7151614 DOI: 10.3390/life10030025] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/02/2020] [Accepted: 03/12/2020] [Indexed: 12/28/2022] Open
Abstract
The significance of the spectral composition of light for growth and other physiological functions of plants moved to the focus of "plant science" soon after the discovery of photosynthesis, if not earlier. The research in this field recently intensified due to the explosive development of computer-controlled systems for artificial illumination and documenting photosynthetic activity. The progress is also substantiated by recent insights into the molecular mechanisms of photo-regulation of assorted physiological functions in plants mediated by photoreceptors and other pigment systems. The spectral balance of solar radiation can vary significantly, affecting the functioning and development of plants. Its effects are evident on the macroscale (e.g., in individual plants growing under the forest canopy) as well as on the meso- or microscale (e.g., mutual shading of leaf cell layers and chloroplasts). The diversity of the observable effects of light spectrum variation arises through (i) the triggering of different photoreceptors, (ii) the non-uniform efficiency of spectral components in driving photosynthesis, and (iii) a variable depth of penetration of spectral components into the leaf. We depict the effects of these factors using the spectral dependence of chloroplast photorelocation movements interlinked with the changes in light penetration into (light capture by) the leaf and the photosynthetic capacity. In this review, we unfold the history of the research on the photocontrol effects and put it in the broader context of photosynthesis efficiency and photoprotection under stress caused by a high intensity of light.
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Affiliation(s)
- Oxana S. Ptushenko
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Vasily V. Ptushenko
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
- N.M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119334 Moscow, Russia
- N.N. Semenov Federal Research Center for Chemical Physics, 119991 Moscow, Russia
| | - Alexei E. Solovchenko
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia
- Institute of Medicine and Experimental Biology, Pskov State University, 180000 Pskov, Russia
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9
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Chlorophyll fluorescence parameters to assess utilization of excitation energy in photosystem II independently of changes in leaf absorption. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2019; 197:111535. [PMID: 31319267 DOI: 10.1016/j.jphotobiol.2019.111535] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/06/2019] [Accepted: 06/14/2019] [Indexed: 01/03/2023]
Abstract
Measurement of Pulse-Amplitude-Modulated (PAM) chlorophyll a fluorescence is widely used method for obtaining information on the functional state of photosystem II (PSII). Recently, it has been shown that some of long-established fluorescence parameters must be interpreted with caution, when the light-induced chloroplast movements occur. In our work we have analyzed the effect of chloroplast movements on these parameters. We have derived new parameters that are independent of the change in PSII absorption occurring during measurement. To verify whether there is a need for new parameters or the difference between the parameters commonly used and the newly derived ones is insignificant, we conducted an experiment with Arabidopsis thaliana wild type plants and its phot1 phot2 mutant defective in chloroplast movement. Plants were exposed to light of different qualities (450, 470, 550 or 660 nm) and quantities (100, 400 or 1200 μmol m-2 s-1) for up to 40 min. Since the blue light-induced chloroplast avoidance reaction is a photoprotective mechanism, we expected that phot1 phot2 mutant will compensate the lack of this mechanism by increasing non-photochemical quenching. However, using the light at both 450 and 470 nm, the calculation of commonly used parameter, ΦNPQ (quantum yield of regulated light-induced thermal energy dissipation in PSII) based on Hendrickson et al. [L. Hendrickson, R.T. Furbank, W.S. Chow, Photosynth. Res. 82 (2004) 73-81] showed the opposite. On the other hand, the results obtained using our newly proposed formulae to determine quantum yield of PSII thermal energy dissipation were in line with our assumption. Thus, the experimental data showed that some formulae of fluorescence parameters are dependent on the change in PSII absorption and need to be interpreted carefully. On the contrary, the formulae introduced by us can remove the effect of changes in PSII absorption that occur during measurement, without additional measurements, and give the real estimate of light-induced non-photochemical quenching.
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10
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Agarwal A, Patil S, Gharat K, Pandit RA, Lali AM. Modulation in light utilization by a microalga Asteracys sp. under mixotrophic growth regimes. PHOTOSYNTHESIS RESEARCH 2019; 139:553-567. [PMID: 29860703 DOI: 10.1007/s11120-018-0526-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 05/28/2018] [Indexed: 05/22/2023]
Abstract
This study is the first to explore the influence of incident light intensity on the photosynthetic responses under mixotrophic growth of microalga Asteracys sp. When grown mixotrophically, there was an enhanced regulation of non-photochemical quenching (NPQ) of the excited state of chlorophyll (Chl) a within the cells in response to white cool fluorescent high light (HL; 600 µmol photons m-2 s-1). Simultaneous measurement of reactive oxygen species (ROS) production as malondialdehyde (MDA) and ascorbate peroxidase (APX), an ROS scavenger, showed improved management of stress within mixotrophic cells under HL. Despite the observed decrease in quantum yield of photosynthesis measured through the Chl a fluorescence transient, no reduction in biomass accumulation was observed under HL for mixotrophy. However, biomass loss owing to photoinhibition was observed in cells grown phototrophically under the same irradiance. The measurements of dark recovery of NPQ suggested that "state transitions" may be partly responsible for regulating overall photosynthesis in Asteracys sp. The partitioning of photochemical and non-photochemical processes to sustain HL stress was analysed. Collectively, this study proposes that mixotrophy using glucose leads to a change in the photosynthetic abilities of Asteracys sp. while enhancing the adaptability of the alga to high irradiances.
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Affiliation(s)
- Akanksha Agarwal
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Mumbai, Maharashtra, 400019, India
| | - Smita Patil
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Mumbai, Maharashtra, 400019, India
| | - Krushna Gharat
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Mumbai, Maharashtra, 400019, India
| | - Reena A Pandit
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Mumbai, Maharashtra, 400019, India.
| | - Arvind M Lali
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Mumbai, Maharashtra, 400019, India
- Department of Chemical Engineering, Institute of Chemical Technology, Mumbai, Maharashtra, 400019, India
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11
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Semer J, Štroch M, Špunda V, Navrátil M. Partitioning of absorbed light energy within photosystem II in barley can be affected by chloroplast movement. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2018; 186:98-106. [PMID: 30025290 DOI: 10.1016/j.jphotobiol.2018.06.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/16/2018] [Accepted: 06/28/2018] [Indexed: 02/03/2023]
Abstract
Plants have developed many ways to protect reaction centres of photosystems against overexcitation. One of the mechanisms involves reduction of the leaf absorption cross-section by light-induced chloroplast avoidance reaction. Decrease in the probability of photon absorption by the pigments bound within photosystem II (PSII) complexes leads to the increase in quantum yield of PSII photochemistry (ΦPSII). On the other hand, the decrease of PSII excitation probability causes reduction of chlorophyll a fluorescence intensity which is manifested as the apparent increase of determined quantum yield of regulated light-induced non-photochemical quenching (ΦNPQ). Absorption of different light intensity by phototropins led to the different chloroplast distribution within barley leaves, estimated by measurement of the leaf transmittance. Due to a weak blue light used for transmittance measurements, leaves exposed to actinic light with wavelengths longer than 520 nm undergo chloroplast accumulation reaction, in contrast with leaves exposed to light with shorter wavelengths, that showed a different extent of chloroplast avoidance reaction. Based on the ΦNPQ action spectra measured simultaneously with the transmittance, the influence of different chloroplast distribution on ΦNPQ was assessed. The analysis of results showed that decrease in the leaf absorption cross-section due to increasing part of chloroplasts reaching profile position significantly affected the partitioning of excitation energy within PSII and such rearrangement also distorted measured ΦNPQ and cannot be neglected in its interpretation. When the majority of chloroplasts reached profile position, the photoprotective effect appeared to be the most prominent for strong blue light that has the highest absorption in the upper leaf layers in comparison with green or red ones.
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Affiliation(s)
- J Semer
- Faculty of Science, University of Ostrava, 30. dubna 22, 701 03 Ostrava, Czech Republic
| | - M Štroch
- Faculty of Science, University of Ostrava, 30. dubna 22, 701 03 Ostrava, Czech Republic; Global Change Research Institute, The Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
| | - V Špunda
- Faculty of Science, University of Ostrava, 30. dubna 22, 701 03 Ostrava, Czech Republic; Global Change Research Institute, The Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
| | - M Navrátil
- Faculty of Science, University of Ostrava, 30. dubna 22, 701 03 Ostrava, Czech Republic.
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