Relationships between the Transition of the Physical Phase of Membrane Lipids and Photosynthetic Parameters in <i>Anacystis nidulans</i> and Lettuce and Spinach Chloroplasts

Murata, Norio; Troughton, John H.; Fork, David C.

doi:10.1104/pp.56.4.508

Cited by 121 publications

(53 citation statements)

References 61 publications

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“…These results appear to reflect differences in membranes of cells grown at 39 and 25 C. The work described in this and in the previous paper extends previous observations which demonstrated cold sensitivity in Anacystis (2,5,6) and a change in the physical state of Anacystis membranes as they are chilled (10).…”

supporting

confidence: 78%

Spectral Changes in Anacystis nidulans Induced by Chilling

Brand¹

1977

Plant Physiol.

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When Anacystis nidulans, strain TX 20 was grown at 39 C, then rapidly chilled to 0 C, a pigment with a carotenoid-ike spectrum was bleached. This effect was not seen when ceUs which had been grown at 25 C were chiRled. The effect seen in 39 C-grown ceUs was not reversible except under extreme conditions such as beating to near boiling for several minutes. Bleaching could be prevented by prior exposure of cells to glutaraldehyde, but could not be reversed by glutaraldehyde treatment following chiUling. The effect occurred upon chiUling 39 C-grown cells even after extensive heating at 85 C, a treatment which destroys phycocyanin and metabolic activities. 25 C-grown cells were induced to bleach by chiRing when suspended in 50% glycerol. The results are interpreted as indicating a chiUl-induced change in aggregation state of a carotenoid, which changes its specific absorbance.As described in the preceding paper (13), Anacystis nidulans exhibits several specific effects when 39 C-grown cells are chilled to near 0 C which are not seen when 25 C-grown cells are treated in the same manner. These results appear to reflect differences in membranes of cells grown at 39 and 25 C. The work described in this and in the previous paper extends previous observations which demonstrated cold sensitivity in Anacystis (2, 5, 6) and a change in the physical state of Anacystis membranes as they are chilled (10).In this report, an additional effect of chilling A. nidulans is described. Bleaching of a pigment, observable spectrophotometrically, is shown to occur in cells grown at 39 C, but not those grown at 25 C. Evidence is presented that bleaching reflects physical changes within the photosynthetic membranes.MATERIALS AND METHODS A. nidulans, strain TX 20, was grown in continuous cultures as described in the preceding paper (13). Cells were routinely chilled to 0 C by placing them in a darkened 50-ml Erlenmeyer flask, then swirling in an ice water bath. The cell suspension was left in the bath for the duration of the chill time. Cell suspensions required approximately 2 min to reach below 4 C. For chill temperatures above 0 C, cells were placed in a darkened container and incubated in a water bath of appropriate temperature for the desired time. For temperatures below 0 C, cells were pelleted and resuspended in 50% (v/v) In experiments requiring glutaraldehyde fixation, cells were pelleted and resuspended in a 2% (v/v) glutaraldehyde solution in 0.05 M K-phosphate buffer (pH 6.8) of the same temperature as the cell suspension. Cell suspensions were kept in darkness during glutaraldehyde treatment.Experiments requiring heated cells were held in a darkened 50-ml Erlenmeyer flask in a water bath of appropriate temperature. The bath was placed over a hot plate with a magnetic stirrer and the contents slowly stirred during heating. A marble was placed over the flask during heating to prevent excessive evaporation.During chilling experiments, a control aliquot was always kept dark at the growth temperature to serve as a reference...

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supporting

confidence: 78%

Spectral Changes in Anacystis nidulans Induced by Chilling

Brand¹

1977

Plant Physiol.

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“…Circadian oscillations in membrane properties of Gonyaulax have been documented and include rhythms in spheroplast membrane fragility (1), membrane electrical potential (1, 2), lipid composition (1), and thylakoid orientation (9). Chl a fluorescence, which also displays a circadian rhythmicity in Gonyaulax, is a sensitive probe of structural changes in the thylakoid and can be particularly responsive to changes in cation concentrations (11) and lipid composition (12). A specific cation and fatty acid effect on photosystem II activity in spinach chloroplasts also has been demonstrated in vitro (19).…”

Section: Resultsmentioning

confidence: 99%

“…x2 analyses for linearity provided a confidence limit greater than 90% for ct 3, ct 6, and ct 9. Summed data for ct 12 To test the circadian nature of light-limited photosynthesis in G. polyedra, photosynthetic rates at saturating (5,000 Uw/cm2) and nonsaturating (2,500 and 1,500 tLw/cm2) light levels were followed through one LD cycle and for 2.5 days following transfer of the cultures to LL (Fig. 3).…”

Section: Resultsmentioning

confidence: 99%

Characterization of Photosynthetic Rhythms in Marine Dinoflagellates

Prézelin¹,

Sweeney²

1977

Plant Physiol.

117

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Using data from light-dark cultures of Gonyaulaxpolyedra entrained to a 24-hour cyde, whole ceUi absorption curves and photosynthesishrradiance curves were constructed for various circadian times. While whole celi absorbance and half-satuntion constants of photosynthesis showed no statisticd difference that could be directly related to the photosynthetic rhythm, the initid slope of the photosynthesis-irradiance curve was a time-dependent parameter which altered in direct proportion to the change in photosynthetic capadty. The results indicated a temporal change in the relative quantum yield of photosynthesis, and the circadian rhythmicity of light-limited photosynthesis was establisbed under constant conditions. Circadian rhythmidty was detected in room temperature chlorophyil fluorescence yield. Low temperature fluorescence kinetics also showed fluctuations. The results suggest that regulation of photosynthesis by the biological dock of Gonyaulax may be mediated through the membrane-bound light reactions and a partial explanation of the underlying mechanism is proposed.Once one accepts the idea that photosynthesis can be regulated by a biological clock, the question is how is the overt rhythm in photosynthetic capacity mediated. Photosynthesis could be regulated either through the membrane-bound light reactions and/or through the more loosely membrane-associated dark reactions involved in CO2 fixation. Observations of conformational changes in chloroplast shape or thylakoid orientation (9, 23), periodicity in shapes of photosynthesis-irradiance curves (16)(17)(18)22), lack of periodicity in dark reaction enzyme activity (3,8), and periodicity in the activity of the photosystems (16,17), have led some workers to suggest that the circadian oscillator regulates photosynthesis through some modifying interaction with the photosystems imbedded in the thylakoid membrane. In contrast, the reported periodicity in glyceraldehyde 3-P-dehydrogenase in Euglena and the lack of periodicity in the relative quantum yield of photosynthesis observed in photosynthesisirradiance curves have been cited by workers who favor mediation by the circadian oscillator through the dark reactions of photosynthesis (25).The difficulty in trying to make an independent interpretation of the results from several of these studies lies in their experimental design. Often only synchronized cultures entrained to light-dark cycles have been used to look for rhythmicity in photosynthetic parameters other than photosynthetic capacity 1 This investigation was supported by National Science Foundation Grant BMS 72-02221A03. (3,(16)(17)(18)25). In these cases, it is difficult to discern whether the observed rhythmicity is derived from a circadian oscillation or the cell division cycle. Similarly, the observation of a diurnal periodicity in a light-dark cycle is not sufficient to demonstrate control by a biological clock. Rather, the rhythmicity of a cell parameter must also free run under constant conditions, be independent of cell division, and hav...

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“…A general trend towards increasing fatty acid unsaturation with decreasing temperature and increasing saturated fatty acids with increasing temperature has been observed in many algae and cyanobacteria (Lynch and Thompson, 1982;Murata et al, 1975;Raison, 1986;Renaud et al, 2002;Sato and Murata, 1980). It has been generally speculated that the ability of algae to alter the physical properties and thermal responses of membrane lipids represents a strategy for enhancing physiological acclimatization over a range of temperatures, although the underlying regulatory mechanism is unknown (Somerville, 1995).…”

Section: Temperaturementioning

confidence: 99%

Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances

et al. 2008

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SummaryMicroalgae represent an exceptionally diverse but highly specialized group of micro-organisms adapted to various ecological habitats. Many microalgae have the ability to produce substantial amounts (e.g. 20-50% dry cell weight) of triacylglycerols (TAG) as a storage lipid under photo-oxidative stress or other adverse environmental conditions. Fatty acids, the building blocks for TAGs and all other cellular lipids, are synthesized in the chloroplast using a single set of enzymes, of which acetyl CoA carboxylase (ACCase) is key in regulating fatty acid synthesis rates. However, the expression of genes involved in fatty acid synthesis is poorly understood in microalgae. Synthesis and sequestration of TAG into cytosolic lipid bodies appear to be a protective mechanism by which algal cells cope with stress conditions, but little is known about regulation of TAG formation at the molecular and cellular level. While the concept of using microalgae as an alternative and renewable source of lipid-rich biomass feedstock for biofuels has been explored over the past few decades, a scalable, commercially viable system has yet to emerge. Today, the production of algal oil is primarily confined to high-value specialty oils with nutritional value, rather than commodity oils for biofuel. This review provides a brief summary of the current knowledge on oleaginous algae and their fatty acid and TAG biosynthesis, algal model systems and genomic approaches to a better understanding of TAG production, and a historical perspective and path forward for microalgae-based biofuel research and commercialization.

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Relationships between the Transition of the Physical Phase of Membrane Lipids and Photosynthetic Parameters in Anacystis nidulans and Lettuce and Spinach Chloroplasts

Cited by 121 publications

References 61 publications

Spectral Changes in Anacystis nidulans Induced by Chilling

Spectral Changes in Anacystis nidulans Induced by Chilling

Characterization of Photosynthetic Rhythms in Marine Dinoflagellates

Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances

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