Light Harvesting in <i>Anacystis nidulans</i> Studied in Pigment Mutants

Myers, Jack; Graham, Jo‐Ruth; Wang, Richard T.

doi:10.1104/pp.66.6.1144

Cited by 209 publications

(144 citation statements)

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“…Samples (1 ml) of cultures were taken at the indicated times, diluted with fresh medium to an OD 750 0.5, and absorbance spectra (500-800 nm) were recorded on a UV/Visible Ultrospec 2100 pro (GE Healthcare Life Sciences). Pigment content was calculated based on absorbance maxima at 631 nm for phycocyanin and 684 nm for chlorophyll a, essentially as described by Myers et al (1980).…”

Section: Methodsmentioning

confidence: 99%

Phosphorylation-independent activation of the atypical response regulator NblR

et al. 2008

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Section: Methodsmentioning

confidence: 99%

Phosphorylation-independent activation of the atypical response regulator NblR

et al. 2008

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“…In cyanobacteria each PSII is reported to contain between 35 and 60 Chl while PSI has about 120 to 140 antenna Chl (10,12,28,31). These antenna sizes have been found to be invariant under a variety of lighting and nutritional conditions (12) and even for mutants deficient in PB (31).…”

Section: Reaction Center and Pb Content And Stoichiometrymentioning

confidence: 99%

Stoichiometry of Photosystem I, Photosystem II, and Phycobilisomes in the Red Alga Porphyridium cruentum as a Function of Growth Irradiance

Cunningham¹,

Dennenberg²,

Mustárdy³

et al. 1989

Plant Physiol.

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Cells of the red alga Porphyridium cruentum (ATCC 50161) exposed to increasing growth irradiance exhibited up to a threefold reduction in photosystems I and 11 (PSI and PSII) and phycobilisomes but little change in the relative numbers of these components. Batch cultures of P. cruentum were grown under four photon flux densities of continuous white light; 6 (low light, LL), 35 (medium light, ML), 180 (high light, HL), and 280 (very high light, VHL) microeinsteins per square meter per second and sampled in the exponential phase of growth. Ratios of PSII to PSI ranged between 0.43 and 0.54. About three PSII centers per phycobilisome were found, regardless of growth irradiance. The phycoerythrin content of phycobilisomes decreased by about 25% for HL and VHL compared to LL and ML cultures. The unit sizes of PSI (chlorophyll/P700) and PSII (chlorophyll/QA) decreased by about 20% with increase in photon flux density from 6 to 280 microeinsteins per square meter per second. A threefold reduction in cell content of chlorophyll at the higher photon flux densities was accompanied by a twofold reduction in a-carotene, and a drastic reduction in thylakoid membrane area. Cell content of zeaxanthin, the major carotenoid in P. cruentum, did not vary with growth irradiance, suggesting a role other than light-harvesting. HL cultures had a growth rate twice that of ML, eight times that of LL, and slightly greater than that of VHL cultures. Cell volume increased threefold from LL to VHL, but volume of the single chloroplast did not change. From this study it is evident that a relatively fixed stoichiometry of PSI, PSII, and phycobilisomes is maintained in the photosynthetic apparatus of this red alga over a wide range of growth irradiance.An ability to adjust the composition of the photosynthetic apparatus to achieve a more efficient harvesting oflight energy is expected to be of significant advantage to organisms which are subjected to long-term variations in the light environment (22). An extensive literature has accumulated on the physiological responses of marine algae and other photosynthetic organisms to changes in intensity and wavelength of the incident light (1,22 this phenomenon in the Rhodophyceae and, iwpaticilar, in the unicellular red alga Porphyridium cruentum (2,3,17,20,(24)(25)(26)38). These earlier studies have examined acclimation in P. cruentum primarily from the perspective of changes in function or activity, including such aspects as action spectra (38) effective absorption cross-sections (25) fluorescence yield spectra (26) and photosynthesis-irradiance curves (24). From previous work in our laboratory (24), it appears that growth under continuous light of a certain, fixed intensity results in physiological changes of advantage to P. cruentum. Cultures grown under low light intensities exhibit a very low compensation point which allows for a net carbon gain under severely limiting quantum flux. Conversely, those cultures grown under high PFD3 have a much greater photosynthetic capacity.The present w...

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“…Before harvesting, the transcription inhibitor Rif (300 mg mL 21 ) was added to prevent further transcriptional activity. Cell density and Chl a content were determined using a UV-VIS spectrophotometer (Myers et al, 1980 Measurements of NAD(P)H (Ryu et al, 2003), Chl a, and AY fluorescence (Teuber et al, 2001;Ryu et al, 2004) from intact cells were performed as described previously. Reduction of the PQ pool was measured after 2 min of dark adaptation using a pulse amplitude modulation fluorometer (Walz) as described previously (Cooley et al, 2000;Cooley and Vermaas, 2001) with a slight modification.…”

Section: Strains and Culture Conditionsmentioning

confidence: 99%

Transcriptional Regulation of the Respiratory Genes in the CyanobacteriumSynechocystissp. PCC 6803 during the Early Response to Glucose Feeding

et al. 2007

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The coordinated expression of the genes involved in respiration in the photosynthetic cyanobacterium Synechocystis sp. PCC 6803 during the early period of glucose (Glc) treatment is poorly understood. When photoautotrophically grown cells were supplemented with 10 mM Glc in the light or after a dark adaptation period of 14 h, significant increases in the respiratory activity, as determined by NAD(P)H turnover, respiratory O 2 uptake rate, and cytosolic alkalization, were observed. At the same time, the transcript levels of 18 genes coding for enzymes associated with respiration increased with differential induction kinetics; these genes were classified into three groups based on their half-rising times. Transcript levels of the four genes gpi, zwf, pdhB, and atpB started to increase along with a net increase in NAD(P)H, while the onset of net NAD(P)H consumption coincided with an increase in those of the genes tktA, ppc, pdhD, icd, ndhD2, ndbA, ctaD1, cydA, and atpE. In contrast, the expression of the atpI/G/D/A/C genes coding for ATP synthase subunits was the slowest among respiratory genes and their expression started to accumulate only after the establishment of cytosolic alkalization. These differential effects of Glc on the transcript levels of respiratory genes were not observed by inactivation of the genes encoding the Glc transporter or glucokinase. In addition, several Glc analogs could not mimic the effects of Glc. Our findings suggest that genes encoding some enzymes involved in central carbon metabolism and oxidative phosphorylation are coordinately regulated at the transcriptional level during the switch of nutritional mode.Respiration releases the energy stored in carbon compounds and also provides many carbon precursors for the biosynthesis of a wide variety of plant biomolecules, including amino acids, lipids, isoprenoids, and porphyrins. D-Glc (hereafter Glc) is an immediate substrate for the four major respiration processes: glycolysis, the oxidative pentose phosphate (OPP) pathway, the tricarboxylic acid (TCA) cycle, and oxidative phosphorylation. In plants, respiration is predominantly controlled by the key metabolites ADP and inorganic phosphate, and the ratio of NADPH to NADP 1 . The cellular concentration of ADP initially controls the rates of electron transfer and ATP synthesis, which in turn affect TCA cycle activity, finally resulting in the regulation of glycolytic reactions.

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Light Harvesting in Anacystis nidulans Studied in Pigment Mutants

Cited by 209 publications

References 20 publications

Phosphorylation-independent activation of the atypical response regulator NblR

Phosphorylation-independent activation of the atypical response regulator NblR

Stoichiometry of Photosystem I, Photosystem II, and Phycobilisomes in the Red Alga Porphyridium cruentum as a Function of Growth Irradiance

Transcriptional Regulation of the Respiratory Genes in the CyanobacteriumSynechocystissp. PCC 6803 during the Early Response to Glucose Feeding

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