CHLOROPHYLL AMOUNT AS AN INDICATOR OF MATTER PRODUCTIVITY IN BIO-COMMUNITIES

The data of chlorophyll amounts in diverse bio-communities arecompiled and discussed with reference to matter production. The chlorophyll amount in euphotic zone of lakes and oceanswas less than 1 g/m², mostly less than 0.1 g/m². In phytoplanktonblooms it was ca. 0.1–1 g/m². Large values of 5–20g/m² were obtained in the outdoor mass cultures of Chlorella,in which the high population density and chlorophyll contentof the alga were observed. In terrestrial higher plant communitiesthe chlorophyll amount (ca. 1–10 g/m²) was usually higherthan in aquatic phytoplankton communities. The largest (13.3g/m²) was obtained with an evergreen gallery forest in Thailand.The chlorophyll amount of desert bio-community could be expectedto be as high as that in water blooms. The maximum chlorophyll amount in bio-communities seems to attainup to 20 g/m² when the conditions are favorable. ¹ Dedicated to Prof. H. TAMIYA on the occasion of his 60th birthday. (Received December 25, 1962; )     

Are Mistletoes Shade Plants? CO2Assimilation and Chlorophyll Fluorescence of Temperate Mistletoes and their Hosts

Mistletoes usually have slower rates of photosynthesis thantheir hosts. This study examines CO₂assimilation, chlorophyllfluorescence and the chlorophyll content of temperate host–parasitepairs (nine hosts parasitized by Ileostylus micranthus and Carpodetusserratus parasitized by Tupeia antarctica). The hosts of I.micranthus had higher mean annual CO₂assimilation (3.59 ±0.41 µmol m^-2 s^-1) than I. micranthus(2.42 ± 0.20µmol m^-2 s^-1), and C. serratus(2.41 ± 0.43 µmolm^-2 s^-1) showed higher CO₂assimilation than T. antarctica(0.67± 0.64 µmol m^-2 s^-1). Hosts saturated at significantlyhigher electron transport rates (ETR) and light levels thanmistletoes. The positive relationship between CO₂assimilationand electron transport suggests that the lower CO₂assimilationrates in mistletoes are a consequence of lower electron transportrates. When photosynthetic rates, ETR and chlorophyll a /b ratioswere adjusted for photosynthetically active radiation, hostsdid not have significantly higher CO₂assimilation (3.21 ±0.37 µmol m^-2 s^-1) than mistletoes (2.54 ± 0.41µmol m^-2 s^-1), but still had significantly higher ETRand chlorophyll a / b ratios. The electron transport rates,saturating light and chlorophyll a / b ratios of sun leavesfrom mistletoes were similar to host shade leaves. These responsesindicate that in comparison with their hosts, mistletoe leaveshave the photosynthetic characteristics of the leaves of shadeplants. Copyright 2000 Annals of Botany Company CO₂assimilation, photosynthetic active radiation (PAR), chlorophyll fluorescence, electron transport rate (ETR), photochemical quenching (q_p), non-photochemical quenching (q_n), sun and shade leaves, chlorophyll content, Ileostylus micranthus, Tupeia antarctica, New Zealand     

Can phaeopigments be used as markers for Daphnia grazing in Lake Constance?

The formation of chlorophyll a degradation products was measuredwith natural phytoplankton from Lake Constance and Daphnia magnaand native Daphnia as grazers in grazing experiments duringspring bloom conditions using high-pressure liquid chromatography(HPLC). Chlorophyll a start concentrations were between 1.2and 16.3 µg l^–1; phaeopigment weights constituted5% of chlorophyll a weight. Only phaeophorbide a was a markerfor Daphnia grazing; concentrations of other phaeopigments (phaeophytina, chlorophyllide a and two unidentified phaeopigments) didnot increase during Daphnia grazing. Conversion efficiencies(chlorophyll a to phaeophorbide a) were between 0 and 43% ona weight basis, and between 0 and 65% on a molar basis. Conversionefficiencies were highest at high grazer density (40 Daphnial^–1) and after a 24 h exposure time. Grazing by microzooplanktonprobably led to the formation of the two unidentified phaeopigments.In Lake Constance, Daphnia density was significantly positivelycorrelated with the phaeophorbide a/chlorophyll a ratio whenit was <5000 Daphnia m^–3. However, when higher Daphniadensities were included in calculations, then Daphnia densitywas positively, but insignificantly, correlated with the phaeophorbidea/chlorophyll a ratio. This suggests that when the level offood per Daphnia is low, then grazing is more efficient withless production of phaeophorbide a and a higher production ofcolourless products.     

Growth of grana from "primary" thylakoids in Phaseolus vulgaris

The plastids of young dark-grown bean leaves, exposed to periodiclight are agranal, devoid of chlorophyll b and contain primarythylakoids and chlorophyll a. Transfer of these plants to continuousillumination results in synthesis of new chlorophyll a, chlorophyllb and grana. This study was done in order to study whether andhow the grana are formed from preexisting primary thylakoids.¹⁴C--aminolevulinic acid was used to label the chlorophyll aof the primary thylakoids, and its fate was studied after transferof the plants to continuous light. It was found that chlorophyll b and grana become ¹⁴C-labelled.The total radioactivity of chlorophyll b per bean increasedwith the parallel decrease of that of chlorophyll a. All subchloroplastfractions, obtained after digitonin disruption of chloroplasts,contained chlorophyll a of equal specific radioactivity. Thespecific radioactivity of chlorophyll b was lower than thatof chlorophyll a, and, in addition, it was lower in the granathan in the stroma lamellae fraction. The data suggest that chlorophyll b is formed from chlorophylla; the grana are formed by stacking of preexisting primary thylakoids;chlorophyll b is synthesized faster in the grana than the stromalamellae; the newly formed chlorophyll a molecules are distributedat random throughout the developing photosynthetic membraneand not on specific growing sites. (Received April 24, 1976; )     

Estimating chlorophyll a abundance from the 'phytoplankton colour' recorded by the Continuous Plankton Recorder survey: validation with simultaneous fluorometry

The green colour (measured with reference to standard colourcharts) of sections of the Continuous Plankton Recorder (CPR)filtering silk was compared with estimates of chlorophyll aconcentration derived from a fluorometer mounted on the CPRduring seven tows in the North Sea between February and May1991. After the green colour was assessed, the abundance ofphytoplankton cells on the filtering silks was quantified bymicroscope analysis. Data were collected for 115 10-nautical-milesamples over a total of seven cruises. For these 115 samples,there was only a weak (F_1.113 = 3.8, P = 0.05, r² = 0.03) positiverelationship between the colour of the filtering silk and thechlorophyll a concentration. However, when this comparison wasrestricted to four tows (68 10-nautical-mile samples) wherethe recorded phytoplankton cell abundance on the silks was verylow, there was a highly significant (F_1.66 /,69.1, P < 0.001,r² = 0.51) positive relationship between the silk colour andthe chlorophyll a concentration. By measuring the relative colourintensity of CPR standard colour categories and quantifyingthe individual variation in the assessment of colour, a theoreticalmodel was developed which pedicted that if the silks were colouredin direct proportion to the chlorophyll a concentration in thewater, then the expert r² for the relationship between silkcolour and chlorophyll a concentration would be 0.62. The greencolour recorded by the CPR survey was therefore identified asa quantitative index of chlorophyll a concentration, but onlywhen numbers of phytoplankton cells on the CPR silks are nothigh.     

Carbon-specific phytoplankton growth rates: a comparison of methods

Measurements of biomass and growth rate of two axenic algalcultures were carried out using three different methodologicalapproaches: the specific ¹⁴C-labelling of chlorophyll a, [³H]adenineincorporation into DNA and net organic carbon assimilation.Time-course experiments revealed that the specific activitiesof chlorophyll a were significantly higher than the specificactivity of total algal carbon in six of seven experiments.When the specific activity of chlorophyll a is used to calculatethe carbon biomass and growth rate, the carbon biomass of thealgae will thus be underestimated and the specific growth ratewill be too high. Determination of growth rates from incorporationof [³H]adenine gave lower values than those obtained from netorganic carbon assimilation and from ¹⁴C incorporation intochlorophyll a. Problems with adenine saturation are suggested.When [³H]adenine is used to measure growth rates in dense algalcultures, additions of >1 µM [³H]adenine are oftenrequired to maximally label the extracellular and intracellularadenine pools and hence DNA.     

Acclimation of Tomato Leaves to Changes in Light Intensity; Effects on the Function of the Thylakoid Membrane

When young tomato plants grown in high light (400 µmolquanta m^–2s^–1 PAR) were transferred to low light(100 µmol quanta m^–2s^–1 PAR), non-cyclic electrontransport capacity was decreased and the rate of dark re-oxidationof Q^–, the first quinone electron acceptor of photosystemII, was decreased within 1–2 d. In contrast, the amountof coupling factor CF₁, assayed by its ATPase activity, decreasedmore gradually over several days. The total chlorophyll contentper unit leaf area remained relatively constant, although thechlorophyll a/chlorophyll b ratio declined. When young tomato plants grown in low light were transferredto high light, the ATPase activity of isolated thylakoids increasedmarkedly within 1 d of transfer. This increase occurred morerapidly than changes in chlorophyll content per leaf area. Inaddition, in vivo chlorophyll fluorescence induction curvesindicate that forward electron transfer from Q^– occurredmore readily. The functional implications of these changes arediscussed. Key words: Tomato, leaves, light intensity, thylakoid membrane     

Some properties of the chlorophyll fluorescence of the diatom Phaeodactylum tricornutum

Fluorescence transients were investigated with the diatom Phaeodactylumtricornutum. Supplementary experiments were done with Chaetocerossp. Under weak excitation ({small tilde}10³ erg/cm²sec), fluorescencetransients were induced simply by die oxidation-reduction reactionof Q, the primary reductant of photosystem II. The action spectraindicated that the electron transfer components between thetwo photosystems were in the most reduced state when fucoxanthinwas excited. The transients were observed with the 681 run emissionand with the 707 nm emission at room temperature. At –196°C,induction due to the reduction of Q. appeared both at the 681and 707 nm emissions. Similar results were also obtained withChaetoceros sp. Under strong excitation (10⁴–10⁵ erg/cm²-sec), the fluorescencetransients due to the interconversion between States 1 and 2of die pigment system (cf. ref. 27, 29) were observed. The transientswere induced by die alternate excitation of chlorophyll a andfucoxanthin or chlorophyll c. Conversion from State 2 to State1 was inhibited by DNP and CCCP, indicating that die processwas energy-dependent. Fluorescence spectra at –196°Cwere not altered by die state-conversion of die pigment system. These results suggest diat all die fluorescence bands whichappeared at room temperature and at –196°C were dueto die chlorophyll a of pigment system II in Phaeodactylum andChaetoceros. (Received September 7, 1972; )     

Field Measurements of the Gas Exchange of Woody Plant Species in Simulated Sunflecks

The photosynthetic responses of eight tree and shrub speciesto simulated sunflecks was measured in the field. The net carbonexchange (NCE) of Corylus avellana and Ulmus glabra increasedwith irradiance up to the maximum irradiance of 230 µmolm^–2 s^–1. The NCE of Fraxinux excelsior, Hedera helixand the sun and shade forms of Rhododendron ponticum saturatedat about 120 µmol m^–2 s^–1 whereas the NCEof Ilex aquifolium, Daphne laureola and Fagus sylvatica hadeffectively saturated at 27 µmol m^–2 s^–1. In all cases the quantum efficiency of NCE could be predictedfrom measurements of chlorophyll fluorescence and the maximumvalue for NCE from measurements of stomatal conductance. Therelationships were combined into a model for predicting NCE/irradiancecharacteristics. Corylus avellana L., Daphne laureola L., Fagus sylvatica L., Fraxinus excelsior L., Hedera helix L., Ilex aquifolium L., Prunus laurocerasus L., Rhododendron ponticum L., Ulmus glabra Huds., gas exchange, stomatal resistance, water use efficiency, chlorophyll fluorescence, quantum efficiency     

Photoconversion of protochlorophyll to chlorophyll a in a mutant of Chlorella regularis

Dark-grown cells of a mutant strain of Chlorella regularis containedchlorophyll a and protochlorophyll, phytyl ester of protochlorophyllide.Under illumination, protochlorophyll was quantitatively anddirectly converted into chlorophyll a. The photoconversion wasdependent on light intensity and temperature and proceeded ina cell-free preparation. The pathway of chlorophyll formation found in the mutant cellsis entirely different from that from protochlorophyllide byway of chlorophyllide a, which is generally observed in greenplants. ¹Present address: Division of Biology, Medical College of Miyazaki,Miyazaki 889-16, Japan. ²Present address: Division of Environmental Biology, The NationalInstitute for Environmental Studies, Ibaragi 300-21, Japan. (Received October 24, 1975; )     

Acclimation in Seedlings of a Tropical Tree, Bischofia javanica, Following a Stepwise Reduction in Light

Acclimation of fully developed leaves of Bischofia javanicaBlume to shadelight was examined. Seedlings were grown undersimulated daylight (1000 µmol m^–2 s^–1), thentransferred to a simulated shadelight (40 µmol m^–2s^–1). When a high-light leaf was transferred to low light, large negativenet photosynthetic rates (P_m) were recorded. This decrease wasrapid, but within 7 d the rate increased and became equal tothe low-light control leaf. These changes in photosynthesisdid not follow the pattern of changes in stomatal conductance(g_s). Transfer to the low light resulted in a dramatic decreasein leaf weight per unit area (L_w), and most of the decreasesin L_w occurred within 3 d of transfer when the P_m of the transferredleaf was well below that of the low-light control leaf. There was a significant decrease in chlorophyll a in the transferredleaf without an appreciable change in chlorophyll b resultingin a large decrease in the chlorophyll a to chlorophyll b ratio.Leaf chlorophylls per unit area were higher in the transferredleaf than the low-light control leaf. Maximum photosyntheticrate in the transferred leaf was decreased by 40% compared tothat for the high-control leaf, but was almost at the same extenthigher than the low-light control leaf The results are discussedin the context of carbon gain capacity of its seedlings underlight-limiting forest understorey habitats. Bischofia, chlorophylls, light, photosynthesis, shade acclimation, tree seedlings, tropical tree     

Conditions de formation d'agr?gats de chlorophylle {alpha} dans des solvants polaires aqueux: polarit? du milieu

The absorbance and emission spectroscopy of chlorophyll a (10^–5M) in water-miscible alcohols, acetone and dioxane were studiedto determine the properties of the chloroplast membranes whichsupport the aggregation of chlorophyll in vivo. It appears thatthe formation of the chlorophyll aggregates is closely dependenton the polarity of their molecular environment. (Received April 16, 1974; )     

Effects of Light on Degradation of Chlorophyll and Proteins during Senescence of Detached Rice Leaves

Regulatory effects of light on senescence of rice leaves wereinvestigated by measuring degradation of chlorophyll and proteinsin leaf segments which had been kept in the dark or under illuminationwith light of different intensities and colors. When leaveshad been left in total darkness for three days at 30°C,there was an initial long lag that lasted for one whole dayand then chlorophyll was rapidly degraded in the second andthird days. Breakdown of chlorophyll was strongly retarded bycontinuous illumination with white light of intensity as lowas 0.5 µmol photons m^–2 s^–1 but the effectof light decreased at intensities above 10 µmol photonsm^–2 s^–2. The initial lag and subsequent degradationof chlorophyll in the dark were little affected by illuminationwith red or far red light at the beginning of dark treatment.However, a brief illumination with red light at the end of thefirst and/or second day significantly suppressed degradationof chlorophyll during subsequent dark periods and the effectof red light was nullified by a short irradiation with far redlight. Thus, degradation of chlorophyll is regulated by phytochrome.Thylakoid membrane proteins and soluble proteins were also largelydegraded during three days in the dark. Degradation of membraneproteins such as the apoproteins of light-harvesting chlorophylla/b proteins of photosystem II and chlorophyll a-binding proteinsof reaction center complexes showed a long lag and was stronglysuppressed by illumination with weak white light. Thus, theloss of chlorophyll can be correlated with degradation of chlorophyll-carryingmembrane proteins. By contrast, light had only a weak protectingeffect on soluble proteins and ribulose-1,5-bisphosphate carboxylase/oxygenaserapidly disappeared under illumination with weak white light.Thus, breakdown of thylakoid membrane and soluble proteins aredifferently regulated by light. Artifacts which would be introducedby detachment of leaves were also discussed. ¹ Present address: Department of Applied Biology, Faculty ofScience and Technology, Science University of Tokyo, Yamazaki,Noda-shi, Chiba, 278 Japan. ² Present address: Department of Life Science, Faculty of Science,Himeji Institute of Technology, Harima Science Park City, Hyogo,678-12 Japan.     

Water-column chlorophyll in an oligotrophic environment: correction for the sampling depths and variations of the vertical structure of density, and observation of a growth period

The chlorophyll content of a water column (WCC), which is commonlyused as an index of the phytoplankton abundance, is affectedby the choice of the sampling depths and by the variations ofthe vertical structure of density. For instance, the thicknessof the water layer, between two sigma-t values, which containsthe deep chlorophyll maximum, can vary with internal waves.The resulting noise often dominates the mesoscale variationsof the observed water-column chlorophyll (OWCC). Sigma-t dependentstatistics (mean, standard deviation) of the chlorophyll concentrationare computed using the observations at 29 casts from a 22-day-longfixed station in an oligotrophic environment at 15•S, 173°E.For each cast, these statistics, the sampling depths, and thewater density at these sampling depths, allow the estimationof a station-dependent ‘expected water-column chlorophyll’(EWCC). The ratio of EWCC to the overall likelihood of WCC duringthe fixed station (i.e. the mean of all OWCC) is a measure ofthe effect of sampling and variable density structure at eachcast. When this effect is removed, the noise in WCC estimatesdecreases significantly. The time variations of WCC during thefixed station then show a trend with relatively high valuesduring the first days, followed by a 12-day-long period withlow values. A regular increase occurred from 1 October, whichwas accompanied by high carbon fixation rates and was mainlydue to an increase of the chlorophyll concentration betweenthe surface and the deep chlorophyll maximum. New productionduring this active phase was estimated to be 535 mgC m^–2day^–1, corresponding to 62% of the total production. Breakingof internal waves which were recorded at the beginning of thegrowth phase and vertical mixing of nutrients can explain theobservation.     

Flag Leaf Photosynthesis of Triticum aestivum and Related Diploid and Tetraploid Species

Rates of net photosynthesis of the flag leaves of 15 genotypesof wheat and related species were measured throughout theirlife, using intact leaves on plants grown in the field. At thestage when rates were maximal, they were in general highestfor the diploid species, intermediate for the tetraploidspeciesand lowest for Triticum aestivum (means of 38, 32 and 28 mgCO₂ dm^–2 h^–1 respectively). Rates were stronglynegatively correlated with leaf area, leaf width and the meanplan area per mesophyll cell and positvely correlated with stomatalfrequency and number of veins per mm of leaf width. The differencesamong species in these attributes were mainly related to ploidylevel. It was not possible to determine the relative importanceof each anatomical feature, though the changes in stomatal frequencyhad only slight effects on stomatal conductance and the observeddifferences in rates of photosynthesis were much greater thanwould be expected from those in stomatal conductance alone. There was genetic variation in rates of light dependent oxygenevolution of isolated protoplasts and intact chloroplasts butno difference attributable to ploidy. The mean rate, 91 µmolO₂ mg^–1 chlorophyll h^–1, equivalent to 3.9 mg CO₂mg^-1chlorophyll h^-1 was considerably less than the rate of photosynthesisin comparable intact leaves, which was 7.2 mg CO₂ mg^–1chlorophyll h^–1. The total above-ground dry matter yields were least for thewild diploids T. urartu and T. thauodar and the wild tetraploidT. dicoccoides, but the other wild diploids produced as muchdry matter as the hexaploids. The prospects of exploiting differences in photosynthetic ratein the breeding of higher yielding varieties are discussed. Triticum aestivum L., wheat, Aegilops spp, photosynthesis, stomatal conductance, stomatal frequency, polyploidy     

A Preliminary Study on the Effects of Nitrogen Supply on the Growth In Vitro of Nine Potato Genotypes (Solanum spp)

Cultures of nine potato genotypes (seven Solanum tuberosum oneS. sparsipilum and one S. oplocense genotypes) were examinedfor their response to growing on medium containing either 60mol m^–3, 40 mol m^–3 or 20 mol m^–3 nitrogen.Genotypes differed in their response to nitrogen. Reducing thenitrogen regime tended to produce taller plants with longerinternodes, shoots had larger leaves but contained less chlorophyll.No change in fresh weight or number of nodes was observed. Genotypex nitrogen interactions were significant for chlorophyll content,shoot length and internode length. Results suggest that thechanges observed were as a result of changes in the total nitrogenlevel rather than changes in the ammonium : nitrate ratio. Thisstudy suggests that for certain potato genotypes, nitrogen levelsin MS medium are too high for producing desirable microplantsin terms of leaf area and shoot length Key words: Solanum tuberosum, S. sparsipilum, S. oplocense, micropropagation, morphogenesis     

Patchiness, collapse and succession of a cyanobacterial bloom evaluated by synoptic sampling and remote sensing

Spatial patchiness and collapse of the cyanobacterium, Nodulariaspumigena, were evaluated in saline Pyramid Lake, Nevada, bytwo synoptic ground surveys and Landsat remote sensing. Horizontalvariation of surface water chlorophyll a during the first surveyranged from 3.6 to 9790 mg m^–3 and Nodularia biovolumewas between 416?10³ and 347?10⁶ µm³ ml^–1. Differencesin spatial and temporal resolution between synoptic ground surveys({small tilde}10m, hours) and Landsat imagery (80m, seconds)yielded a poor correlation when data were matched by commonground location. A regression model for estimating chlorophyllfrom Landsat radiance was developed by pairing equivalent frequenciesfrom cumulative relative frequency distributions of both variables.Wind driven advection precipitated bloom collapse shortly afterthe first synoptic sample and Nodularia mineralization producedhigh epilimnetic ammonium concentrations. Ammonium, silica fromfluvial sources, and density differences between river and lakewater masses stimulated succession to a Chaetoceros elmoreibloom within 8 days of the first synoptic survey. The 16 dayfly by interval of Landsat is too long to document such short-termbloom succession. Landsat imagery is most applicable for evaluatinginstantaneous, basin-scale horizontal patchiness and averagelakewide chlorophyll concentrations, while frequent synopticground surveys yield more accurate estimates of meso- and micro-scalephytoplankton patchiness and species succession.     

An efficient excitation energy transfer from a carotenoid, siphonaxanthin to chlorophyll a observed in a deep-water species of chlorophycean seaweed

Excitation spectra of chlorophyll a fluorescence and absorptionspectra of the thalli of Ulva japonica and Ulva pertusa werestudied at room temperature. Both the fluorescence excitationspectrum and absorption spectrum of the former showed a characteristicbroad peak at 540 nm, which those of the latter lacked. It wasinferred that siphonaxanthin in the former efficiently transferredits excitation energy to chlorophyll a. ¹ Contributions from the Shimoda Marine Research Center, No.312. (Received August 30, 1976; )     

Effect of light regime upon growth rate and chemical composition of a clone of Skeletonema costatum from the Trondheimsfjord, Norway

Nutrient-saturated cultures of Skeletonema costatum were grownat 15C and 42 combinations of photon flux density (PFD) anddaylength. The growth rate increased with the daylength andPFD up to 460–630 µE m^–2 s^–1 (maximum2.5 doublings day At 2000 µE m^–2 s^–1 the growthrate was reduced by 45%. The chlorophyll (chl) content of thecells and the rate of production of carbon per unit chlorophylland ambient light increased for declining light regimes as didcellular nitrogen and carbon. The N/C ratio, cellular phosphorusand ratios between in vivo fluorescence, with and without DCMU,and chlorophyll varied negligibly. The ATP/C ratio was linearlyrelated to the growth rate. The results were described mathematically.The chl/C ratio was low both in strong light and in marginallylow light, corresponding to low cellular chlorophyll and highcellular carbon, respectively. The observed increase in cellularnitrogen and carbon at shade adaptation probably represent anincrease in the size of internal stores of organic nitrogenand may imply that Skeletonema cells become enriched with organicnitrogen when staying in nitrate-rich subsurface layers, e.g.in or below a nutricline. However, close to zero growth in marginallight the cells become greatly enriched with respect to everymeasured factor. Such cells may be physiologically resting stageswhich may ensure survival during dark periods and promote rapiddevelopment during the initial phase of blooms. Cultures andnatural blooms of Skeleronema in the Trondheimsfjord exhibitvery similar patterns of variation.     

Studies on the absorption spectra of chlorophyll a in aqueous dispersions of lipids from the photosynthetic membranes

The absorption spectra of chlorophyll a were studied in aqueousdispersions of four major lipid components present in the thylakoidmembranes. Chlorophyll a in aqueous dispersions of uncharged galactolipidsrevealed two absorption bands, at 670 and 745 nm, when the molecularratio of chlorophyll to lipid was higher than 0.2. The latterband may be due to the formation of microcrystals of chlorophylla. Chlorophyll a in aqueous dispersions of negatively chargedlipids revealed a single absorption band at 670 nm. However,chlorophyll a was decomposed during measurement in these lipiddispersions. The absorption spectra of chlorophyll a in aqueous dispersionsof mixture of galactolipid and charged lipid were apparentlysimilar to those of chlorophyll a in the charged lipid dispersion.Chlorophyll a, however, was not decomposed in these aqueousdispersions of lipid mixtures. It is concluded that the presence of both galactolipid and chargedlipid are necessary to reconstruct the state of chlorophylla dissolved in the lipid phase in the thylakoid membranes. The red absorption band of chlorophyll a in the reconstructedsystem composed of chlorophyll a, charged and uncharged lipids,appeared at 670 nm with a half bandwidth of 22 nm. Analysisof the absorption spectrum in the fourth derivative and thecurve-fitting methods indicated that the red band was composedmainly of a single band with a peak at 670–671 nm. ¹ Present address: Department of Biology, College of GeneralEducation, University of Tokyo, Komaba, Meguro-ku, Tokyo 153,Japan. (Received October 13, 1977; )