Mechanism of the light state transition in photosynthesis. IV. Picosecond fluorescence spectroscopy of Anacystis nidulans and Porphyridium cruentum in state 1 and state 2 at 77 K

Bruce, Doug; Biggins, John; Steiner, T.; Thewalt, M. L. W.

doi:10.1016/0005-2728(85)90101-x

Cited by 89 publications

(46 citation statements)

References 32 publications

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“…Despite some uncertainty in the fitting of the data to a theoretical model, nonetheless it is undebatable and striking that energy transfer from PE at the periphery of the PBsome antenna to the PBsome terminal emitter occurs very rapidly (e.g., in 70 psec in P. cruentum), thus accounting for the ef- Since the initial studies of Porter's group with P. cruentum, picosecond time-resolved measurements have been extended to several related systems. These include measurements of the intact cells of several species of cyanobacteria [9,10,12,58,106,107,155] and red algae [10,12,71,106,117,155] ; isolated PBsomes [46, 58,66,69,115,130,136,147] ; andPBsome components [23,24,28,62,63,65,67,70,79,137,146]. Several innovations were introduced to make these measurements more meaningful, including use of time-resolved fluorescence spectra [106,155], selective excitation of individual biliproteins by use of tunable lasers with application of both fluorescence and transient absorption techniques [69] and transient anisotropy [46].…”

Section: Excitation Energy Transfermentioning

confidence: 99%

“…Such regulation has been shown to occur in vivo in both red algae [5--7, 12, 71, 89, 90, 109, 121, 125] and cyanobacteria [12,31]. Preferential excitation of PS II or PS I results in the transition of cells to State I or State II, with concomitant alterations in the levels of PSI or PS II fluorescence, electron transport rates and effective absorption cross-sections.…”

Section: Biophysical and Biochemical Studies Of Phycobilisomephotomentioning

confidence: 99%

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Phycobilisome structure and function

1986

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Phycobilisomes are aggregates of light-harvesting proteins attached to the stroma side of the thylakoid membranes of the cyanobacteria (blue-green algae) and red algae. The water-soluble phycobiliproteins, of which there are three major groups, tetrapyrrole chromophores covalently bound to apoprotein. Several additional protiens are found within the phycobilisome and serve to link the phycobiliproteins to each other in an ordered fashion and also to attach the phycobilisome to the thylakoid membrane. Excitation energy absorbed by phycoerythrin is transferred through phycocyanin to allophycocyanin with an efficiency approximating 100%. This pathway of excitation energy transfer, directly confirmed by time-resolved spectroscopic measurements, has been incorporated into models describing the ultrastructure of the phycobilisome. The model for the most typical type of phycobilisome describes an allophycocyanin-containing core composed of three cylinders arranged so that their longitudinal axes are parallel and their ends form a triangle. Attached to this core are six rod structures which contain phycocyanin proximal to the core and phycoerythrin distal to the core. The axes of these rods are perpendicular to the longitudinal axis of the core. This arrangement ensures a very efficient transfer of energy. The association of phycoerythrin and phycocyanin within the rods and the attachment of the rods to the core and the core to the thylakoid require the presence of several 'linker' polypeptides. It is recently possible to assemble functionally and structurally intact phycobilisomes in vitro from separated components as well as to reassociate phycobilisomes with stripped thylakoids. Understanding of the biosynthesis and in vivo assembly of phycobilisomes will be greatly aided by the current advances in molecular genetics, as exemplified by recent identification of several genes encoding phycobilisome components.Combined ultrastructural, biochemical and biophysical approaches to the study of cyanobacterial and red algal cells and isolated phycobilisome-thylakoid fractions are leading to a clearer understanding of the phycobilisome-thylakoid structural interactions, energy transfer to the reaction centers and regulation of excitation energy distribution. However, compared to our current knowledge concerning the structural and functional organization of the isolated phycobilisome, this research area is relatively unexplored.

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Section: Excitation Energy Transfermentioning

confidence: 99%

Section: Biophysical and Biochemical Studies Of Phycobilisomephotomentioning

confidence: 99%

Phycobilisome structure and function

1986

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“…The ectoplasmic face particles exhibit a nonrandom alignment into long rows in state 1 and a more random distribution in state 2. Linear dichroism studies have also shown that the state transition in cyanobacteria is associated with changes in the orientation of APC and Chl a (Bruce and Biggins, 1985;Brimble and Bruce, 1989;HomerDixon et al, 1994).…”

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confidence: 99%

Regulation of the Distribution of Chlorophyll and Phycobilin-Absorbed Excitation Energy in Cyanobacteria. A Structure-Based Model for the Light State Transition

et al. 2002

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The light state transition regulates the distribution of absorbed excitation energy between the two photosystems (PSs) of photosynthesis under varying environmental conditions and/or metabolic demands. In cyanobacteria, there is evidence for the redistribution of energy absorbed by both chlorophyll (Chl) and by phycobilin pigments, and proposed mechanisms differ in the relative involvement of the two pigment types. We assayed changes in the distribution of excitation energy with 77K fluorescence emission spectroscopy determined for excitation of Chl and phycobilin pigments, in both wild-type and state transition-impaired mutant strains of Synechococcus sp. PCC 7002 and Synechocystis sp. PCC 6803. Action spectra for the redistribution of both Chl and phycobilin pigments were very similar in both wild-type cyanobacteria. Both state transitionimpaired mutants showed no redistribution of phycobilin-absorbed excitation energy, but retained changes in Chl-absorbed excitation. Action spectra for the Chl-absorbed changes in excitation in the two mutants were similar to each other and to those observed in the two wild types. Our data show that the redistribution of excitation energy absorbed by Chl is independent of the redistribution of excitation energy absorbed by phycobilin pigments and that both changes are triggered by the same environmental light conditions. We present a model for the state transition in cyanobacteria based on the x-ray structures of PSII, PSI, and allophycocyanin consistent with these results.The effective absorption of sunlight by antenna pigments is the critical first step in photosynthesis. All oxygenic photosynthetic organisms share a common core antenna pigment complement of about 40 chlorophyll (Chl) a in PSII and about 100 Chl a in PSI (Rö gner et al., 1990). Photosynthetic organisms do not, however, limit their photon capturing ability to this level, but rather use some form of additional peripheral antenna pigments to increase the effective "absorption cross section" of one or both PSs. Higher plants and algae have evolved diverse mechanisms to increase their ability to absorb sunlight. In cyanobacteria, the soluble phycobiliproteins are organized into phycobilisomes (PBSs), which are primarily associated excitonically with PSII in a manner analogous to the family of intrinsic thylakoid membrane Chl a/b-containing light-harvesting complex polypeptides (LHCII), which serve the same function in higher plants (Glazer, 1984; Zilinskas and Greenwald, 1986).Both cyanobacteria and higher plants can regulate the efficiency of excitation energy transfer to the two PSs. The light state transition appears designed to adjust the relative activities of PSII and PSI in response to a dynamic environment or to changing metabolic demands (Yu et al., 1993). The mechanism in higher plants involves a reversible association of LHCII with PSII and PSI triggered by the redox state of intersystem electron transport carriers and driven by the reversible phosphorylation of LHCII (for review, see Allen, 1992; Woll...

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“…Phytoplankton blooms are a accepted due to conflicting experimental evidence permanent feature of the system, with chlorophyll a (e.g. Bruce et al 1985). An alternative hypothesis (chl a) concentrations frequently reaching 100 mg m-3…”

Section: Introductionmentioning

confidence: 99%

In situ measurement of state transition in cyanobacterial blooms:kinetics and extent of the state change in relation to underwater light and vertical mixing

Schubert¹,

Rm²,

Sagert³

1995

Mar. Ecol. Prog. Ser.

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ABSTRACT. Measurements of spectral scalar irradiance were made in a shallow estuarine system during a phytoplankton bloom in summer 1994. High concentrations of dissolved organic matter (DOM) and pigments resulted in strong attenuation of light within the upper 1 m of the water column. Spectral analysis showed an increase in the ratio of far-red p 7 0 0 nm) irradiance to total photosynthetically available radiation (PAR) as depth increased. Under these conditions it is expected that state transition may occur, as far-red light is preferentially absorbed by Photosystem 1 (PSI). Measurements of fluorescence emission at 77K from natural phytoplankton samples as well as from laboratory-grown unialgal cultures showed that redistribution of excitation energy between the photosystems occurred in response to changes in the spectral light environment. Exposure to the far-red-enriched lower euphotic zone induced State 1 (whereby more light energy was directed towards Photosystem 2, PS2), whereas algae reverted to State 2 (redirection of light energy away from PS2) at the surface or after exposure to near-dark conditions at the bottom of the euphotic zone. Differences in the kinetics of state transition between green algae and cyanobacteria together with estimation of the wind-induced mixing time of the water column are discussed with respect to photoacclimation. For both natural phytoplankton and laboratory cultures, state transition occurred on a time scale equal to or faster than the time required for 1 vertical mixing cycle. The faster response of cyanobacteria to changes in spectral irradiance in the water column may be an important factor contributing to cyanobacterial dominance in hypertrophic waters under light-limited conditions.

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Mechanism of the light state transition in photosynthesis. IV. Picosecond fluorescence spectroscopy of Anacystis nidulans and Porphyridium cruentum in state 1 and state 2 at 77 K

Cited by 89 publications

References 32 publications

Phycobilisome structure and function

Phycobilisome structure and function

Regulation of the Distribution of Chlorophyll and Phycobilin-Absorbed Excitation Energy in Cyanobacteria. A Structure-Based Model for the Light State Transition

In situ measurement of state transition in cyanobacterial blooms:kinetics and extent of the state change in relation to underwater light and vertical mixing

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