Spinach-thylakoid phosphorylation: Studies on the kinetics of changes in photosystem antenna size, spill-over and phosphorylation of light-harvesting chlorophyll ab protein

1986 ◽  
Vol 850 (3) ◽  
pp. 483-489 ◽  
Author(s):  
Robert C. Jennings ◽  
Khalid Islam ◽  
Giuseppe Zucchelli
Keyword(s):  
Light Harvesting ◽  
Antenna Size ◽  
Spinach Thylakoid ◽  
Kinetics Of

Spectroscopic methods in photosynthesis: photosystem stoichiometry and chlorophyll antenna size

1989 ◽  
Vol 323 (1216) ◽  
pp. 397-409 ◽  
Keyword(s):  
Plant Species ◽  
Light Harvesting ◽  
Electron Flow ◽  
Vascular Plant ◽  
Thylakoid Membranes ◽  
Reaction Centre ◽  
Antenna Size ◽  
Fluorescence Measurements ◽  
Photosystem Stoichiometry ◽  
Absorption Of Light

Light-induced absorbance change and fluorescence measurements were employed in the quantitation of photosystem stoichiometry and in the measurement of the chlorophyll (Chl) antenna size in thylakoid membranes. Results with thylakoid membranes from diverse photosynthetic tissues indicated a PSII/PSI reaction-centre stoichiometry that deviates from unity. Cyanobacteria and red algae have a PSII/PSI ratio in the range of 0.3 to 0.7. Chloroplasts from spinach and other vascular-plant species grown under direct sunlight have PSII/PSI = 1.8±0.3. Chlorophyll b -deficient and Chi b -lacking mutants have PSII/PSI > 2. The observation that PSII/PSI ratios are not unity and show a large variation among different photosynthetic membranes appears to be contrary to the conventional assumption derived from the Z-scheme. However, the photosystem stoichiometry is not the only factor that needs to be taken into account to explain the coordination of the two photosystems in the process of linear electron transport. The light-harvesting capacity of each photosystem must also be considered. In cyanobacterial thylakoids (from Synechococcus 6301, PSII/PSI = 0.5±0.2), the phycobilisome-PSII complexes collectively harvest as much light as the PSI complexes. In vascular plant chloroplasts, the light-harvesting capacity of a PSI I complex (250 molecules, Chi a/Chi b = 1.7) is lower than that of a PSI complex (230 Chl, Chl a /Chl b = 8.0) because Chi b has a lower extinction coefficient than Chi a . A differential attenuation of light intensity through the grana further reduces the light absorbed by PSII. Hence, a PSII/PSI ratio greater than one in vascular-plant chloroplasts compensates for the lower absorption of light by individual PSII complexes and ensures that, on average, PSII will harvest about as much light as PSI. In conclusion, distinct light-harvesting strategies among diverse plant species complement widely different photosystem stoichiometries to ensure a balanced absorption of light and a balanced electron flow between the two photoreactions, thereby satisfying the requirement set forth upon the formulation of the Z-scheme by Hill & Bendall ( Nature, Lond. 186, 136-137 (1960)) and by Duysens, Amesz & Kamp ( Nature, Lond . 190, 510-511 (1961)).

Characterisation of Leaf Fluorescence of Sodium-Deficient C4 Plants: Kinetics of Emissions From Whole Leaves and Fluorescence Properties of Isolated Thylakoids

1989 ◽  
Vol 16 (6) ◽  
pp. 459 ◽  
Author(s):  
CPL Grof ◽  
DBC Richards ◽  
M Johnston ◽  
PF Brownell
Keyword(s):  
Light Harvesting ◽  
Polynomial Function ◽  
Bundle Sheath ◽  
C4 Plants ◽  
Degree Polynomial ◽  
Amaranthus Tricolor ◽  
Fluorescence Kinetics ◽  
C4 Species ◽  
Chloris Gayana ◽  
Kinetics Of

Examination of whole-leaf fluorescence kinetics by means of a second-degree polynomial function showed a decrease in the rate of the rise from Fd to Fp in sodium-deficient compared with normal leaves of the C4 species Kochia childsii and Amaranthus tricolor. This suggests a decreased efficiency in light harvesting and/or utilisation in sodium-deficient plants. Fluorescence ratios (Fv/Fo) of separated mesophyll and bundle sheath thylakoids were both lower from leaves of sodium-deficient compared with normal plants of K. childsii, Chloris gayana, A. edulis and A. tricolor.

Inhibition of State Transition and Light-Harvesting Complex II Phosphorylation-Mediated Changes in Excitation Energy Distribution in the Thylakoids of SANDOZ 9785-Treated Plants

1995 ◽  
Vol 50 (1-2) ◽  
pp. 77-85
Author(s):  
Manoj K. Joshi ◽  
Prasanna Mohanty ◽  
Salil Bose
Keyword(s):  
Energy Distribution ◽  
State Transition ◽  
Light Harvesting ◽  
Lhc Ii ◽  
Ps Ii ◽  
Light Harvesting Complex ◽  
Antenna Size ◽  
Complex Ii ◽  
Ps I ◽  
Light Harvesting Complex Ii

Abstract Thylakoids isolated from SAN 9785 (4-chloro-5-dimethylamino-2-phenyl-3(2H)-pyridazi-none)-treated pea plants showed an inhibition of “state transition” and the light-harvesting complex II (LHC II) phosphorylation-mediated changes in the energy distribution between photosystem II (PS II) and photosystem I (PS I) as measured by a decrease in PS II and an increase in PS I fluorescence yield. Interestingly, in these thylakoids the extent of phosphorylation-induced migration of light-harvesting complex (LHC II-P) to non-appressed mem­brane regions was only marginally inhibited. We propose that the suppression in the ability for “state transition” by SANDOZ 9785 (SAN 9785) treatment occurs due to a lack of effec­tive coupling of the migrated LHC II-P and PS I. Since we observed a decrease in the antenna size of PS I of the treated plants, the lack of effective coupling is attributed to this decrease in the antenna size of PS I.

Kinetics of the appearance of mRNA for light-harvesting chlorophyll a/b protein in polysomes of barley

Planta ◽  
1980 ◽  
Vol 148 (5) ◽  
pp. 448-452 ◽  
Author(s):  
Michael Müller ◽  
Maija Viro ◽  
Christiane Balke ◽  
Klaus Kloppstech
Keyword(s):  
Chlorophyll A ◽  
Light Harvesting ◽  
Kinetics Of

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.

scholarly journals Genetic Complementation and Kinetic Analyses ofRhodobacter capsulatus ORF1696 Mutants Indicate that the ORF1696 Protein Enhances Assembly of the Light-Harvesting I Complex

1998 ◽  
Vol 180 (7) ◽  
pp. 1759-1765 ◽  
Author(s):  
C. S. Young ◽  
R. C. Reyes ◽  
J. T. Beatty
Keyword(s):  
Absorption Spectrum ◽  
Parental Strain ◽  
Rhodobacter Capsulatus ◽  
Light Harvesting ◽  
Major Effect ◽  
Complex Assembly ◽  
Mutant Strains ◽  
Assembly Kinetics ◽  
Kinetics Of ◽  
Steady State Absorption

ABSTRACT Rhodobacter capsulatus ORF1696 mutant strains were created by insertion of antibiotic resistance cartridges at different sites within the ORF1696 gene in a strain that lacks the light-harvesting II (LHII) complex. Steady-state absorption spectroscopy profiles and the kinetics of the light-harvesting I (LHI) complex assembly and decay were used to evaluate the function of the ORF1696 protein in various strains. All of the mutant strains were found to be deficient in the LHI complex, including one (ΔNae) with a disruption located 13 codons before the 3′ end of the gene. A 5′-proximal disruption after the 31st codon of ORF1696resulted in a mutant strain (ΔMun) with a novel absorption spectrum. The two strains with more 3′ disruptions (ΔStu and ΔNae) were restored nearly to the parental strain phenotype when transcomplemented with a plasmid expressing the ORF1696 gene, but ΔMun was not. The absorption spectrum of ΔMun resembled that of a strain which had a polar mutation in ORF1696. We suggest that a rho-dependent transcription termination site exists between the MunI and proximal StuI sites ofORF1696. A comparison of LHI complex assembly kinetics showed that assembly occurred 2.6-fold faster in the parental strain than in strain ΔStu. In contrast, LHI complex decay occurred 1.7-fold faster in the ORF1696 parental strain than in ΔStu. These results indicate that the ORF1696 protein has a major effect on LHI complex assembly, and models of ORF1696 function are proposed.

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