Integration of physiologically relevant photosynthetic energy flows into whole genome models of light-driven metabolism

Characterizing photosynthetic productivity is necessary to understand the ecological contributions and biotechnology potential of plants, algae, and cyanobacteria. Light capture efficiency and photophysiology have long been characterized by measurements of chlorophyll fluorescence dynamics. However, these investigations typically do not consider the metabolic network downstream of light harvesting. In contrast, genome-scale metabolic models capture species-specific metabolic capabilities but have yet to incorporate the rapid regulation of the light harvesting apparatus. Here we combine chlorophyll fluorescence parameters defining photosynthetic and non-photosynthetic yield of absorbed light energy with a metabolic model of the pennate diatom Phaeodactylum tricornutum. This integration increases the model predictive accuracy regarding growth rate, intracellular oxygen production and consumption, and metabolic pathway usage. Additionally, our simulations recapitulate the link between mitochondrial dissipation of photosynthetically-derived electrons and the redox state of the photosynthetic electron transport chain. We use this framework to assess engineering strategies for rerouting cellular resources toward bioproducts. Overall, we present a methodology for incorporating a common, informative data type into computational models of light-driven metabolism for characterization, monitoring and engineering of photosynthetic organisms.

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The quantum yield of photosynthetic electron transport evaluated by chlorophyll fluorescence as an indicator of drought tolerance in durum wheat

The Journal of Agricultural Science ◽

10.1017/s0021859600084823 ◽

1995 ◽

Vol 125 (3) ◽

pp. 325-329 ◽

Cited By ~ 23

Author(s):

Z. Flagella ◽

D. Pastore ◽

R. G. Campanile ◽

N. Di Fonzo

Keyword(s):

Chlorophyll Fluorescence ◽

Electron Transport ◽

Quantum Yield ◽

Drought Tolerance ◽

Durum Wheat ◽

Photosynthetic Electron Transport ◽

Fluorescence Measurement ◽

Chlorophyll Fluorescence Parameters ◽

Percentage Decrease ◽

Induction Curve

SUMMARYThe chlorophyll fluorescence parameters ΔF/Fm′ and Fv′/Fm′, related respectively to the quantum yield of photosynthetic electron transport and to the efficiency of excitation capture by the open centres of photosystem II, have been evaluated as possible indicators of drought tolerance in durum wheat. ΔF/Fm′ and Fv′/Fm′ measurements were carried out on excised leaves, both control and dehydrated, of 25 cultivars. ΔF/Fm′ and Fv′/Fm′ values were obtained at two times after the start of fluorescence measurement: at 14 s, i.e. during the induction curve (ΔF/Fm′14s and Fv′/Fm′14s) and at 200s, i.e. at steady state fluorescence (ΔF/Fm′200s and Fv′/Fm′200s).In dehydrated leaves a mean significant decrease of 20% (P < 0·001) was observed in ΔF/Fm′14s values. In contrast, no great differences were observed between control and dehydrated leaves with regard to ΔF/Fm′200s, Fv′/Fm′14s and Fv′/Fm′200s.The percentage decrease of ΔF/Fm′14s after dehydration was correlated with the drought susceptibility index (DSI) of the cultivars, evaluated on a yield basis and a significant correlation (r = 0·72, P < 0·001) was found.

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Effect of Herbicides on the Photosynthetic Rate and Chlorophyll Fluorescence of Solidago canadensis L.

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.356-360.2785 ◽

2011 ◽

Vol 356-360 ◽

pp. 2785-2790 ◽

Cited By ~ 1

Author(s):

Liu Qing Yang ◽

Fei Yong Liao ◽

Kun Zhao

Keyword(s):

Chlorophyll Fluorescence ◽

Photosynthetic Rate ◽

Electron Transport Rate ◽

Photosynthetic Electron Transport ◽

Photochemical Quenching ◽

Solidago Canadensis ◽

Chlorophyll Fluorescence Parameters ◽

Photosynthetic Rates ◽

Fluorescence Parameters ◽

Metsulfuron Methyl

Solidago canadensis L. was treated with metsulfuron-methyl, fluroxypyr and iso-propyl glyphosate. The photosynthetic rate and chlorophyll fluorescence parameters were measured. The results showed that after treated 13 days later, the intrinsic conversion efficiency of light energy decreased, treatment A1B3 had the largest decline, which was 81.6 % of the control, the changes of treatments treated with iso-propyl glyphosate were not obvious; the photochemical quenching parameter of all treatments decreased, treatment A2B2 had the largest decline, which was 42.6 % of control; the photosynthetic electron transport rate decreased obviously, treatment A1B2，A1B3 and A2B2 had the largest decline, which was 20.0 % of control; the net photosynthetic rate decreased greatly, treatment A2B2 and A2B3 drooped more than others, which were 11.3% and 17.8% of control respectively. After treated 50 days later, the plants treated with metsulfuron-methyl and fluroxypyr were dead, whose net photosynthetic rates were zero. The net photosynthetic rates of the plants treated with iso-propyl glyphosate decreased to varying degrees, but plants were alive. Result shows that metsulfuron-methyl and fluroxypyr could be used to kill the Solidago canadensis L., the plants would be dead after treated 50 days later.

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Features of chlorophyll fluorescence transients can be used to investigate low temperature induced effects on photosystem II of algal lichens from polar regions ( Short Communication )

Czech Polar Reports ◽

10.5817/cpr2015-1-10 ◽

2015 ◽

Vol 5 (1) ◽

pp. 99-111 ◽

Cited By ~ 12

Author(s):

Anamika Mishra ◽

Josef Hájek ◽

Tereza Tuháčková ◽

Miloš Barták ◽

Kumud Bandhu Mishra

Keyword(s):

Chlorophyll Fluorescence ◽

Lichen Species ◽

Freezing Stress ◽

Slow Phase ◽

Ps Ii ◽

Chlorophyll Fluorescence Parameters ◽

Fluorescence Parameters ◽

Species Specific ◽

Fluorescence Transients ◽

Chlorophyll Fluorescence Transients

Chlorophyll fluorescence is an effective tool for investigating characteristics of any photosynthesizing organisms and its responses due to different stressors. Here, we have studied a short-term temperature response on three Antarctic green algal lichen species: Umbilicaria antarctica, Xanthoria elegans, and Rhizoplaca melanophtalma. We measured slow chlorophyll fluorescence transients in these Antarctic lichen species during slowely cooling of thallus temperature from 20°C to 5, 0 and -5°C with 20 minute acclimation at each temperature. The measurements were supplemented with saturation pulses for the analysis of chlorophyll fluorescence parameters: maximum yield of PS II photochemistry (FV/FM), effective quantum yield of PS II photochemistry (FPSII) and quenching parameters. In response to decreasing thallus temperature, we observed species-specific changes in chlorophyll fluorescence parameters as well as in the shape of the chlorophyll fluorescence transients. We propose that species-specific changes in the slow phase of chlorophyll fluorescence transients can be potentially used as indicators of freezing stress in photosynthetic apparatus of lichen algal photobionts.

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EFFECTS OF PESTICIDE ON THE CHLOROPHYLL FLUORESCENCE PARAMETERS IN NO-HEADING CHINESE CABBAGE

Acta Horticulturae ◽

10.17660/actahortic.2010.856.28 ◽

2010 ◽

pp. 211-216

Author(s):

Z.K. Gao ◽

T. Zhao ◽

M. Wang ◽

W.L. Zhang ◽

J.P. He ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

Chinese Cabbage ◽

Chlorophyll Fluorescence Parameters ◽

Fluorescence Parameters ◽

Heading Chinese Cabbage

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Plant Physiology, 2021 Functional redox links between lumen thiol oxidoreductase1 and serine/threonine-protein kinase STN7

Plant Physiology ◽

10.1093/plphys/kiab091 ◽

2021 ◽

Cited By ~ 1

Author(s):

Jianghao Wu ◽

Liwei Rong ◽

Weijun Lin ◽

Lingxi Kong ◽

Dengjie Wei ◽

...

Keyword(s):

Protein Kinase ◽

Disulfide Bonds ◽

Kinase Activity ◽

Light Harvesting ◽

Photosynthetic Electron Transport ◽

State Transitions ◽

Light Harvesting Complex ◽

Light Harvesting Complex Ii

Abstract In response to changing light quantity and quality, photosynthetic organisms perform state transitions, a process which optimizes photosynthetic yield and mitigates photo-damage. The serine/threonine-protein kinase STN7 phosphorylates the light-harvesting complex of photosystem II (PSII; light-harvesting complex II), which then migrates from PSII to photosystem I (PSI), thereby rebalancing the light excitation energy between the photosystems and restoring the redox poise of the photosynthetic electron transport chain. Two conserved cysteines forming intra- or intermolecular disulfide bonds in the lumenal domain (LD) of STN7 are essential for the kinase activity although it is still unknown how activation of the kinase is regulated. In this study, we show lumen thiol oxidoreductase 1 (LTO1) is co-expressed with STN7 in Arabidopsis (Arabidopsis thaliana) and interacts with the LD of STN7 in vitro and in vivo. LTO1 contains thioredoxin (TRX)-like and vitamin K epoxide reductase domains which are related to the disulfide-bond formation system in bacteria. We further show that the TRX-like domain of LTO1 is able to oxidize the conserved lumenal cysteines of STN7 in vitro. In addition, loss of LTO1 affects the kinase activity of STN7 in Arabidopsis. Based on these results, we propose that LTO1 helps to maintain STN7 in an oxidized active state in state 2 through redox interactions between the lumenal cysteines of STN7 and LTO1.

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Response of Photosynthesis and Chlorophyll Fluorescence Parameters of Castanopsis kawakamii Seedlings to Forest Gaps

Forests ◽

10.3390/f11010021 ◽

2019 ◽

Vol 11 (1) ◽

pp. 21

Author(s):

Zhong-sheng He ◽

Rong Tang ◽

Meng-jia Li ◽

Meng-ran Jin ◽

Cong Xin ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

Light Intensity ◽

Seedling Growth ◽

Group Treatment ◽

Control Group ◽

Low Light ◽

Chlorophyll Fluorescence Parameters ◽

Forest Gaps ◽

Low Light Intensity ◽

Weak Light

Light is a major environmental factor limiting the growth and survival of plants. The heterogeneity of the light environment after gap formation in forest influences the leaf chlorophyll contents, net photosynthetic rate (Pn), and chlorophyll fluorescence, thus influencing the growth and regeneration of Castanopsis kawakamii seedlings. The aim of this study was to explore the effects of weak light on the photosynthetic physiology of C. kawakamii seedlings in forest gaps and non-gaps. The results showed that (1) the contents of chlorophyll a (Chl-a), chlorophyll b (Chl-b), and total chlorophyll (Chl-T) in forest gaps were lower than in non-gaps. Seedlings tended to increase chlorophyll content to absorb light energy to adapt to low light intensity in non-gap environments. (2) The Pn values of C. kawakamii seedlings in forest gaps were significantly higher than in non-gaps, and forest gaps could improve the seedlings’ photosynthetic capacity. (3) The C. kawakamii seedlings in forest gaps were more sensitive to weak light and control group treatment, especially the tall seedlings, indicating that seedlings require more light to satisfy their growth needs in the winter. The seedlings in non-gaps demonstrated better adaptability to low light intensity. The light intensity was not adequate in weak light conditions and limited seedling growth. We suggest that partial forest selection cutting could improve light intensity in non-gaps, thus promoting seedling growth and regeneration of C. kawakamii more effectively in this forest.

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Photoinduced toxicity of fluoranthene on primary processes of photosynthesis in lichens

The Lichenologist ◽

10.1017/s0024282907006111 ◽

2006 ◽

Vol 39 (1) ◽

pp. 91-100 ◽

Cited By ~ 11

Author(s):

Marie KUMMEROVÁ ◽

štěpán ZEZULKA ◽

Jana KRULOVÁ ◽

Jan TŘÍSKA

Keyword(s):

Chlorophyll Fluorescence ◽

Bioconcentration Factor ◽

Lichen Species ◽

Chlorophyll Fluorescence Parameters ◽

Fluorescence Parameters ◽

Photochemical Processes ◽

Symbiotic Algae ◽

Lasallia Pustulata ◽

Photoinduced Toxicity ◽

Umbilicaria Hirsuta

The effect of increasing concentrations (0·01, 0·1, 1 and 5 mg l−1) of intact (FLT) and photo-modified (phFLT) fluoranthene and the duration of exposure (1, 2, 3, 5 and 7 days) on the chlorophyll fluorescence parameters (F0, FV/FM, and ΦII) of symbiotic algae in the thalli of two foliose lichens Lasallia pustulata and Umbilicaria hirsuta was investigated. In addition the FLT concentration in thalli of both lichen species was determined and a bioconcentration factor (BCF) was calculated. The results obtained demonstrated that the concentrations of FLT and especially phFLT (1 and 5 mg l−1) applied affected primary photochemical processes of photosynthesis in the algae of both lichen species. The F0 value increased and the FV/FM and ΦII values decreased. The fluoranthene content in the thallus of both lichen species increased with increasing FLT concentration in the environment.

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The Relationship between the Binding of Dicyclohexylcarbodiimide and Quenching of Chlorophyll Fluorescence in the Light-Harvesting Proteins of Photosystem II†

Biochemistry ◽

10.1021/bi9809369 ◽

1998 ◽

Vol 37 (33) ◽

pp. 11586-11591 ◽

Cited By ~ 26

Author(s):

Alexander V. Ruban ◽

Paolo Pesaresi ◽

Ulrich Wacker ◽

Klaus-Dieter J. Irrgang ◽

Roberto Bassi ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

Photosystem Ii ◽

Light Harvesting ◽

The Relationship

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Photosynthetic response to nitrogen source and different ratios of nitrogen and phosphorus in toxic cyanobacteria, Microcystis aeruginosa FACHB-905

Journal of Limnology ◽

10.4081/jlimnol.2016.1458 ◽

2016 ◽

Cited By ~ 3

Author(s):

Guotao Peng ◽

Zhengqiu Fan ◽

Xiangrong Wang ◽

Chen Chen

Keyword(s):

Chlorophyll Fluorescence ◽

Algal Blooms ◽

Freshwater Ecosystems ◽

Cyanobacterial Blooms ◽

Photosynthetic Response ◽

Nitrogen And Phosphorus ◽

Ammonium Toxicity ◽

Chlorophyll Fluorescence Parameters ◽

Fluorescence Parameters ◽

N Assimilation

The frequent outbreak of cyanobacterial blooms has become a worldwide phenomenon in freshwater ecosystems. Studies have elucidated the close relationship between harmful algal blooms and nutrient contents, including the loading of nitrogen and the ratios of nitrogen (N) and phosphorus (P). In this study, the effect of inorganic (nitrate and ammonium) and organic (urea) nitrogen at varied N/P ratios on the Microcystis aeruginosa FACHB-905 accumulation and photosynthesis was investigated. The optimal NO3/P in this study were 30~50 indicated by the cell abundance (4.1×106/mL), pigment concentration (chlorophyll a 3.1 mg/L, phycocyanin 8.3mg/L), and chlorophyll fluorescence parameters (rETR, Ek, α, φPSII and Fv/Fm values), while too high NO3-N (N/P=100:1) would cause an intracellular nitrate inhibition, leading to a decrease of photosynthetic activity. In addition, low concentration of NH4-N (N/P=4:1) would favor the M. aeruginosa growth and photosynthesis, and high NH4/P ratio (>16) would rise the ammonium toxicity of algal cells and affect the N assimilation. In urea treatments, M. aeruginosa responded similarly to the NH4-N treatments both in growth curves and pigment contents, and the favorable N/P ratio was between 16~30, suggested by the chlorophyll fluorescence parameters. The results demonstrated that the various chemical forms of N and N/P ratios have a significant impact on Microcystis abundance and photosynthesis. More work is needed to figure out the mechanism of nitrogen utilization by Microcystis and the photosynthetic response to nutrient stress at the molecular level.

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