scholarly journals Photosystem Electron-Transport Capacity and Light-Harvesting Antenna Size in Maize Chloroplasts

1984 ◽  
Vol 74 (4) ◽  
pp. 993-998 ◽  
Author(s):  
Maria L. Ghirardi ◽  
Anastasios Melis
Keyword(s):  
Electron Transport ◽  
Light Harvesting ◽  
Transport Capacity ◽  
Antenna Size ◽  
Light Harvesting Antenna

scholarly journals Fine-tuning the photosynthetic light harvesting apparatus for improved photosynthetic efficiency and biomass yield

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
N. Friedland ◽  
S. Negi ◽  
T. Vinogradova-Shah ◽  
G. Wu ◽  
L. Ma ◽  
...  
Keyword(s):  
Electron Transport ◽  
Cross Section ◽  
Photosynthetic Efficiency ◽  
Biomass Yield ◽  
Light Harvesting ◽  
Fine Tuning ◽  
Antenna Size ◽  
Full Sunlight ◽  
Optical Cross Section ◽  
Light Harvesting Antenna

Abstract Photosynthetic electron transport rates in higher plants and green algae are light-saturated at approximately one quarter of full sunlight intensity. This is due to the large optical cross section of plant light harvesting antenna complexes which capture photons at a rate nearly 10-fold faster than the rate-limiting step in electron transport. As a result, 75% of the light captured at full sunlight intensities is reradiated as heat or fluorescence. Previously, it has been demonstrated that reductions in the optical cross-section of the light-harvesting antenna can lead to substantial improvements in algal photosynthetic rates and biomass yield. By surveying a range of light harvesting antenna sizes achieved by reduction in chlorophyll b levels, we have determined that there is an optimal light-harvesting antenna size that results in the greatest whole plant photosynthetic performance. We also uncover a sharp transition point where further reductions or increases in antenna size reduce photosynthetic efficiency, tolerance to light stress, and impact thylakoid membrane architecture. Plants with optimized antenna sizes are shown to perform well not only in controlled greenhouse conditions, but also in the field achieving a 40% increase in biomass yield.

scholarly journals Loss of CpSRP54 function leads to a truncated light-harvesting antenna size in Chlamydomonas reinhardtii

2017 ◽  
Vol 1858 (1) ◽  
pp. 45-55 ◽  
Author(s):  
Jooyeon Jeong ◽  
Kwangryul Baek ◽  
Henning Kirst ◽  
Anastasios Melis ◽  
EonSeon Jin
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Light Harvesting ◽  
Antenna Size ◽  
Light Harvesting Antenna

scholarly journals Modelling the role of LHCII-LHCII, PSII-LHCII and PSI-LHCII interactions in state transitions

2019 ◽  
Author(s):  
W. H. J. Wood ◽  
M. P. Johnson
Keyword(s):  
Monte Carlo ◽  
Protein Complex ◽  
Thylakoid Membrane ◽  
State Transition ◽  
Complex Dynamics ◽  
Light Harvesting ◽  
State Transitions ◽  
Antenna Size ◽  
Light Harvesting Antenna ◽  
Novel Algorithm

AbstractThe light-dependent reactions of photosynthesis take place in the plant chloroplast thylakoid membrane, a complex three-dimensional structure divided into the stacked grana and unstacked stromal lamellae domains. Plants regulate the macro-organization of photosynthetic complexes within the thylakoid membrane to adapt to changing environmental conditions and avoid oxidative stress. One such mechanism is the state transition which regulates photosynthetic light harvesting and electron transfer. State transitions are driven by changes in the phosphorylation of light harvesting antenna complex II (LHCII), which cause a decrease in grana diameter and stacking, a decreased energetic connectivity between photosystem II (PSII) reaction centres and an increase in the relative LHCII antenna size of photosystem I (PSI) compared to PSII. Phosphorylation is believed to drive these changes by weakening the intra-membrane lateral PSII-LHCII and LHCII-LHCII interactions and the inter-membrane stacking interactions between these complexes, while simultaneously increasing the affinity of LHCII for PSI. We investigated the relative roles and contributions of these three types of interaction to state transitions using a lattice-based model of the thylakoid membrane based on existing structural data, developing a novel algorithm to simulate protein complex dynamics. Monte Carlo simulations revealed that state transitions are unlikely to lead to a large-scale migration of LHCII from the grana to the stromal lamellae. Instead, the increased light harvesting capacity of PSI is largely due to the more efficient recruitment of LHCII already residing in the stromal lamellae into PSI-LHCII supercomplexes upon its phosphorylation. Likewise, the increased light harvesting capacity of PSII upon dephosphorylation was found to be driven by a more efficient recruitment of LHCII already residing in the grana into functional PSII-LHCII clusters, primarily driven by lateral interactions.Statement of significanceFor photosynthesis to operate at maximum efficiency the activity of the light-driven chlorophyll-protein complexes, photosystems I and II (PSI and PSII) must be fine-tuned to environmental conditions. Plants achieve this balance through a regulatory mechanism known as the state transition, which modulates the relative light-harvesting antenna size and therefore excitation rate of each photosystem. State transitions are driven by changes in the extent of the phosphorylation of light harvesting complex II (LHCII), which modulate the interactions between PSI, PSII and LHCII. Here we developed a novel algorithm to simulate protein complex dynamics and then ran Monte Carlo simulations to understand how these interactions cooperate to affect the organization of the photosynthetic membrane and bring about state transitions.

Changes in in vivo fluorescence quenching in rye and barley as a function of reduced PSII light harvesting antenna size

1994 ◽  
Vol 91 (4) ◽  
pp. 551-558 ◽  
Author(s):  
Stefan Falk ◽  
Marianna Krol ◽  
Denis P. Maxwell ◽  
David A. Rezansoff ◽  
Gordon R. Gray ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Light Harvesting ◽  
Antenna Size ◽  
In Vivo Fluorescence ◽  
Light Harvesting Antenna

Changes in in vivo fluorescence quenching in rye and barley as a function of reduced PSII light harvesting antenna size

1994 ◽  
Vol 91 (4) ◽  
pp. 551-558 ◽  
Author(s):  
Stefan Falk ◽  
Marianna Krol ◽  
Denis P. Maxwell ◽  
David A. Rezansoff ◽  
Gordon R. Gray ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Light Harvesting ◽  
Antenna Size ◽  
In Vivo Fluorescence ◽  
Light Harvesting Antenna

Photosystem II Heterogeneity in Triazine-Resistant and Susceptible Biotypes of Chenopodium album

1987 ◽  
Vol 42 (6) ◽  
pp. 794-797 ◽  
Author(s):  
Jack J. S. van Rensen ◽  
Leon E. E M. Spätjens
Keyword(s):  
Photosystem Ii ◽  
Light Harvesting ◽  
Chenopodium Album ◽  
Antenna Size ◽  
Photosystem Ii Heterogeneity ◽  
Light Harvesting Antenna

The heterogeneity of photosystem II with respect to α and β centers was investigated in triazine-resistant and susceptible biotypes of Chenopodium album . In both biotypes the light harvesting antenna sizes of photosystem II α centers was larger than those of β centers. In the resistant biotype the antenna size of the α centers was smaller than those in the susceptible one. There was not much difference in the antenna sizes of the β centers. The proportion of β centers was larger in the resistant biotype compared with the sensitive one.

scholarly journals Up-regulation of bundle sheath electron transport capacity under limiting light in C4Setaria viridis

2021 ◽  
Author(s):  
Maria Ermakova ◽  
Chandra Bellasio ◽  
Duncan Fitzpatrick ◽  
Robert T. Furbank ◽  
Fikret Mamedov ◽  
...  
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Redox Regulation ◽  
Light Harvesting ◽  
Electron Flow ◽  
Crop Improvement ◽  
Reducing Power ◽  
Bundle Sheath ◽  
Transport Capacity ◽  
Shade Acclimation

AbstractC4 photosynthesis is a biochemical pathway that operates across mesophyll and bundle sheath (BS) cells to increase CO2 concentration at the site of CO2 fixation. C4 plants benefit from high irradiance but their efficiency decreases under shade causing a loss of productivity in crop canopies. We investigated shade acclimation responses of a model NADP-ME monocot Setaria viridis focussing on cell-specific electron transport capacity. Plants grown under low light (LL) maintained CO2 assimilation rates similar to high light plants but had an increased chlorophyll and light-harvesting-protein content, predominantly in BS cells. Photosystem II (PSII) protein abundance, oxygen-evolving activity and the PSII/PSI ratio all increased in LL BS cells indicating a higher capacity for linear electron flow. PSI, ATP synthase, Cytochrome b6f and the chloroplastic NAD(P) dehydrogenase complex, which constitute the BS cyclic electron flow machinery, were all upregulated in LL plants. A decline in PEP carboxylase activity in mesophyll cells and a consequent shortage of reducing power in BS chloroplasts was associated with the more oxidised redox state of the plastoquinone pool in LL plants and the formation of PSII - light-harvesting complex II supercomplexes with an increased oxygen evolution rate. Our results provide evidence of a redox regulation of the supramolecular composition of Photosystem II in BS cells in response to shading. This newly identified link contributes to understanding the regulation of PSII activity in C4 plants and will support strategies for crop improvement including the engineering of C4 photosynthesis into C3 plants.Significance statementThe efficiency of C4 photosynthesis decreases under low irradiance causing a loss of productivity in crop canopies. We investigate shade acclimation of a model NADP-ME monocot, analysing cell-specific protein expression and electron transport capacity. We propose a regulatory pathway controlling abundance and activity of Photosystem II in bundle sheath cells in response to irradiance.

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