Photosynthetic electron transport in relation to thylakoid membrane composition and organization

Arc, J. Barber

doi:10.1111/1365-3040.ep11612111

Cited by 85 publications

(33 citation statements)

References 85 publications

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“…The dynamic nature of these responses has led several to conclude that the primary effect of R is complex, involves more than one aspect of photosynthesis, and can be mitigated by other processes in the system (17,23). For example, it has been pointed out that decreased QA to QB electron transport in R plants is more rapid than the normally rate-limiting oxidation of plastoquinol (4,24), whereas other studies indicate that this step may be rate limiting (20).…”

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confidence: 99%

Pleiotropy in Triazine-Resistant Brassica napus

Dekker¹,

Burmester²

1992

Plant Physiol.

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Studies were conducted that supported the hypothesis that the mutation to the psbA plastid gene that confers S-triazine resistance (R) in Brassica napus also results in an altered diurnal pattern of photosynthetic carbon assimilation (A) relative to that of the susceptible (S) wild type, and that these patterns change over the ontogeny of a plant. Photosynthetic photon flux density, under closely controlled environmental conditions, was incrementally increased and decreased on either side of the midday maxima of 1150 to 1300 ;tmol quanta m-2 s-'. In all experiments, A approximately tracked the increasing and decreasing diurnal light levels. Younger (3-to 4-leaf) R plants had greater photosynthetic rates early and late in the diurnal light period, whereas those of S plants were greater during midday as well as during the photoperiod as a whole. These relative photosynthetic characteristics of R and S plants changed in several ways with ontogeny. As the plants aged during the vegetative phase of development, S plants gradually assimilated more carbon in the early, and then in the late, part of the day. At the end of the vegetative phase of development, R plant carbon assimilation was less relative to S plants at most times of the day, and was never greater. This relationship between the two biotypes dramatically changed with the onset of the reproductive phase (81/2 to 91/2 leaf) of plant development: R plants assimilated more carbon than S plants during all periods of the diurnal light period with the exception of the late part of the day. In addition to these differences in A, R plant stomatal function differed from that in S plants. R plant leaves were always cooler than S plant leaves under the same environmental and diurnal conditions. Correlated with this difference in leaf temperature were equal or greater total conductances to water vapor and intercellular CO2 partial pressures in R compared to S leaves in most instances. These studies indicate a more complex pattern of photosynthetic carbon assimilation than previously observed. The photosynthetic superiority of one biotype relative to the other was a function of the time of day and the age of the plant. These thus, the codon 264 change in the psbA gene caused a change in its product, the Dl protein, a key functional element in PSII electron transport (28). R2 plants have a decreased quantum efficiency of CO2 assimilation compared to S plants (15). This decreased efficiency is due to the altered redox state of PSII quinone acceptors and a shift in the equilibrium constant between QA-and QB in favor of QA-(2). What is less clear in the literature is whether this change in Dl structure and electron transport function directly modifies whole-leaf photosynthesis and plant productivity or only indirectly influences these functions (14).The genetic change in R plants leads to a profound reorganization of functional units in the chloroplast. This pleiotropic cascade includes both structural (25) and functional changes (2). Many of these changes in R ar...

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confidence: 99%

Pleiotropy in Triazine-Resistant Brassica napus

Dekker¹,

Burmester²

1992

Plant Physiol.

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“…The cytochrome b/f complex seems to be evenly distributed or located in the border regions between the appressed and nonappressed regions. For a detailed overview on the organization of the thylakoid membrane the reader is referred to a review by Barber (1983).…”

Section: Function and Organization Of The Thylakoid Membranementioning

confidence: 99%

“…Another difference is that the content of cytochrome b/f complex differs in the various preparations. Whether this is due to selective removal of the complex during isolation, or to its location in the border region between appressed and non-appressed regions as suggested by Barber (1983) and Ghirardi and Melis (1983), remains to be established. The detergent-derived photosystem II particles obtained according to Berthold et al (1981) show a substantial loss oflipids (Gounaris et al 1983).…”

Section: Choice Of Preparationmentioning

confidence: 99%

The Chloroplast Thylakoid Membrane—Isolation, Subfractionation and Purification of Its Supramolecular Complexes

Andersson¹,

Anderson²

1985

Cell Components

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“…In contrast the photosystem two (PS2) complexes, together with the light-harvesting chlorophyll a/b-protein, a r e mainly located in the appressed thylakoid regions. It has been suggested that cytochrome b6-f complex is located in both appressed and non-appressed regions [3,11 ] but other considerations favour a distribution of this complex closer to PS1 than PS2 [7,16,19]. This spatial segregation of complexes in the plane of the membrane raises questions concerning electron transfer and energy distribution between the two photosystems [ 2 , 6 ] .…”

Section: Introductionmentioning

confidence: 99%

“…There are no sterols present so that based on the lipid composition the thylakoid membrane should be a highly fluid system at room temperature. Recent steady-state [13,15] and time dependent [14] anisotropy studies of the fluorescence emission from the hydrophobic probe, 1,6-diphenyl-1,3,5-hexatriene (DPH) support this contention and further suggest that no phase change occurs in the bulk lipid matrix down to --20°C [7,12]. However, other studies have indicated that regulation of the thylakoid fluidity in response to different growth temperatures is not achieved by alterations in the composition or unsaturation levels of the lipids but is brought about by changing the protein to lipid ratio [8,9].…”

Section: Introductionmentioning

confidence: 99%

Fluidity properties of isolated chloroplast thylakoid lipids

et al. 1984

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Chloroplast thylakoid lipids have been isolated free of photosynthetic pigments using a combination of high performance liquid and thin layer chromatography. The hydrophobic fluorescent probe, 1,6-diphenyl-1,3,5-hexatriene (DPH) has been incorporated into aqueous dispersions of the isolated lipids in order to investigate dynamic and structural properties of the resulting bilayer membranes. Time dependent fluorescence anisotropy decays have been measured and analysed assuming the wobbling-in-cone model (Kinosita et al., Biophys J 20 (1977) 289-305). The DPH fluorescence lifetimes and the static and dynamic fluorescence anisotropy decay parameters for the probe in a total lipid mixture or in pure digalactosyldiacylglycerol (DGDG), changed in a predictable way with increasing temperature (10°-36°C). For a given temperature, it was found that the total lipid mixture was in general less ordered and showed greater dynamic motion as judged from DPH fluorescence anisotropy and compared with the pure DGDG system, although at 36°C differences in dynamic parameters were less evident. Overall the results obtained emphasize the highly fluid nature of thylakoid membrane lipids and give a basis for investigating how intrinsic proteins modify structural and dynamic properties of the in vivo membrane.

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Photosynthetic electron transport in relation to thylakoid membrane composition and organization

Cited by 85 publications

References 85 publications

Pleiotropy in Triazine-Resistant Brassica napus

Pleiotropy in Triazine-Resistant Brassica napus

The Chloroplast Thylakoid Membrane—Isolation, Subfractionation and Purification of Its Supramolecular Complexes

Fluidity properties of isolated chloroplast thylakoid lipids

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