Alterations in Pigment Content in Leaves of Pisum sativum After Exposure to Supplementary UV-B

Pea plants were either illuminated with visible light supplementedwith ultraviolet-B (UV-B) radiation for five days, or transferredback to control light after short exposures (hours) to UV-B.Spectra of NaOH-extracted pigments from UV-B-exposed plantsshowed a decrease in absorption in the visible region and anincrease in the UV region: the former a consequence of the lossof chlorophyll, the latter probably due to induced synthesisof protective pigments. The decrease in chlorophyll absorptionwas an earlier event than the increase in UV absorption. Inextracts from plants which had recovered, the increase in UVabsorption was greater than in leaves subjected to three daysof UV-B. This stresses the importance of recovery from UV-Bfor extensive synthesis of protective pigments. Analysis oftetrapyrrolic pigments showed that UV-B treatment caused noallomerization of chlorophylls. Formation of chlorophyllidesa and b was greatly enhanced during the degradation of chlorophylls;however, the concentrations of chlorophyllides were three ordersof magnitude lower than those of the chlorophylls and did notincrease greatly as chlorophyll degradation progressed. No protoporphyrinIX, uro- or copro-porphyrins III were detected, which suggeststhat early steps in chlorophyll synthesis are not affected byUV-B light. (Received May 15, 1992; Accepted August 6, 1992)     

The Influence of Stress Conditions on Chlorophyll Content of Two Range Grasses with Contrasting Photosynthetic Pathways

The influence of various treatments and temperature regimeson total chlorophylls and on the chlorophyll a:b ratio of westernwheatgrass and blue grama plants was investigated at differenttime intervals during the 120-day growth period. Western wheatgrass,a C₃ species, accumulated greater amounts of chlorophyll thandid blue grama plants, a C₄ species. Maximum concentrations(mg gd wt^–1) of chlorophylls in western wheatgrass andin blue grama were recorded at the lower (13/7°C) and higher(30/18°C) temperature regimes. Nitrogen fertilizer alonedecreased the chlorophyll content in both species. The chlorophylla:b ratio in blue grama ranged from an average of 2·00under irrigated plus fertilized conditions to 3·00 undercontrol and fertilized conditions. On the other hand, the chlorophylla:b ratio in western wheatgrass remained constant at 3·00throughout the growing season under various treatments and temperatureregimes.     

Chlorophyll a forms in mesophyll and bundle sheath chloroplasts of Zea mays leaves grown at low light intensity

Mesophyll and bundle sheath chloroplasts were prepared fromleaves of Zea mays grown at light intensities of 1.1 and 240µW/cm², respectively. The mesophyll chloroplasts thatdeveloped at the low intensity and bundle sheath chloroplatsthat developed at both low and high intensities showed higherratios of chlorophyll a/b and P700/chlorophylls compared withthe normal ratios found for the mesophyll chloroplasts thathad developed at the high intensity. Derivative absorption spectrophotometryat 77?K revealed that the low intensity mesophyll chloroplastscontained more of chlorophyll a forms with longer wavelengthred bands than high intensity mesophyll chloroplasts. More ofthe longer wavelength forms of chlorophyll a were also presentin the bundle sheath chloroplasts that had developed at lowand high intensities. All these four types of chloroplasts showedtwo peaks of fluorescence, one at 687 hra and the other at 733or 738 nm. In addition to these peaks, the high intensity mesophyllchloroplasts showed a shoulder at 697 nm, and the two typesof bundle sheath chloroplasts showed a shoulder at 680 nm. (Received June 17, 1974; )     

Biomass-pigment relationships in potamoplankton

During most of the growing season of 1994, pigment content,as determined by HPLC analysis of algal sample extracts, wasfollowed in the River Meuse (Belgium) potamoplankton. The concentrationof some algal pigments (chlorophylls a and b, fucoxanthin, lutein,echinenone and alloxanthin) was related to biomass estimatesof total phytoplankton and of major taxonomic components (diatoms,green algae, cyanobacteria and cryptomonads). Highly significantlinear regressions were obtained for chlorophyll a-total biomass,fucoxanthin-diatoms, lutein-green algae, chlorophyll b-greenalgae. However, no relationship was found for cyanobacteriaor cryptomonads and their specific pigments, which may be attributedto poor accuracy of biomass estimates for these non-dominantalgae. In conclusion, the good relationship found for dominantalgae and their specific pigments confirms the value of pigmentsas quantitative markers of phytoplankton, as detected in othermarine and freshwater environments.     

On the microparticles which pass through glass fiber filter type GF/F in coastal and open waters

The chlorophyll a content of nicroparticles which passed throughglass fiber filters Whatman type GF/F but were retained on 0.2µm Nuclepore membranes was analyzed on a weekly basisover the course of 1 year in Kaneohe Bay, Hawaii. Depth profileswere also obtained at four oceanic stations off the islandsof Maui and Molokai, Hawaii. Experimental evidence indicatedthat these microparticles were photosynthetically active. Theproportion of microparticulate chlorophyll a could be up to35% of picoplankton chlorophyll a (2.0–0.2 µm sizerange) retained on a single pass through a 0.2 p.m Nucleporefilter. The filtrate from both GFIF and 0.2µm Nucleporefilters was found to contain chlorophyll a which could be retainedon a subsequent pass through either 0.2 µm Nuclepore orGF/F filters. Only serial filtration can ensure that essentiallyall picoplankton have been filtered from the water when eitherof these types of filters is used.     

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.     

CHLOROPHYLL FORMATION IN ISOLATED PUMPKIN COTYLEDONS IN THE PRESENCE OF KINETIN AND CHLORAMPHENICOL

Investigations have been made on the changes in the levels ofprotochlorophyll, chlorophyll a and chlorophyll b in relationto the kinetin induced expansion of isolated pumpkin cotyledonsin the presence and absence of chloramphenicol. It has been shown that rise in pigment level keeps pace withexpansion growth of the cotyledons. Kinetin markedly promotes the synthesis of protochlorphyll withoutmuch affecting the rate of its photoreduction to chlorophyll. Chloramphenicol strongly inhibits the development of both chlorophylla and b. The inhibition seems to be due to its interferenceboth with the synthesis of protochlorophyll and its subsequentconversion to chlorophyll. The inhibitory effect of chloramphenicol on the formation ofchlorophyll a is greater than on that of chlorophyll b, suggestingthereby the probability of divergent pathways for the formationof the two chlorophylls. (Received December 21, 1966; )     

Enzymatic Conversion of Pheophorbide a to the Precursor of Pyropheophorbide a in Leaves of Chenopodium album

Soluble proteins extracted from leaves of Chenopodium albumcatalyzed the conversion of pheophorbide a to a precursor ofpyropheophorbide a, putatively identified as C-13²-carboxyl-pyropheophorbidea. The precursor was then decarboxylated non-enzymatically toyield pyropheophorbide a. Soluble proteins and pheophorbidea, as the substrate, were required for the formation of theprecursor, and boiled proteins were enzymatically inactive.The maximum rate of conversion of pheophorbide a to the precursoroccurred at pH 7.5. The K_m for pheophorbide a was 12.5 µMat pH 7.0. Both pheophorbide b and bacteriopheophorbide a couldserve as substrates, but protopheophorbide a could not. Formationof methanol was detected during the enzymatic reaction, an indicationthat the enzyme is an esterase. Among seven alcohol analogstested, only methanol inhibited the enzymatic activity uncompetitively,with a K₁ of 71.6 mM. Mass-spectrometric (MS) analysis of theprecursor yield a peak at m/z 579 that indicated the releaseof a methyl group from pheophorbide a. It appears thereforethat the enzyme catalyzes the demethylation of the carbomethoxygroup at C-13² of pheophorbide a by hydrolysis to yield methanoland the precursor, C-13²-carboxyl-pyropheophorbide a, whichis converted to pyropheophorbide a by spontaneous decarboxylation.We have tentatively designated the enzyme "pheophorbidase".The presence of the enzyme was dependent on plant species andit was expressed constitutively. ¹Present address: Faculty of Science, Shizuoka University, Ohya,Shizuoka, 422 Japan     

Ultrastructural Changes in Chloroplasts of Quercus rotundifolia Lam. in Response to Evernic Acid

The amount of total chlorophyll, chlorophylls a and b as wellas the ratio of a to b decreased in chloroplasts isolated fromQuercus rotundifolia leaves, kept for 17 d in a solution of35.5 µM evernic acid in 1 mM Na HCO₃, when compared withthe chloroplasts of control leaves (kept in NaHCO₃). The chloroplastsin the spongy parenchyma were smaller and the amount of starchand plastoglobuli lower. The number of grana per chloroplastsection, the number of thylakoids per grana and the height ofgrana stacks were also less in the chloroplasts of leaves treatedwith evernic acid. Quantitative ultrastructural differenceswere determined by means of electron microscopy and image analysistechniques. Quercus rotundifolia Lam., chloroplasts, ultrastructure, lichens, evernic acid     

Comparison of east and west chlorophyll a standing stock and oceanic habitat along the Transition Domain of the North Pacific

Chlorophyll (Chl) a was measured every 10 m from 0 to 150 min the Transition Domain (TD), located between 37 and 45°N,and from 160°E to 160°W, in May and June (Leg 1) andin June and July (Leg 2), 1993–96. Total Chl a standingstocks integrated from 0 to 150 m were mostly within the rangeof 20 and 50 mg m^–2. High standing stocks (>50 mg m^–2)were generally observed westof 180°, with the exceptionof the sporadic high values at the easternmost station. Thetotal Chl a standing stock tended to be higher in the westernTD (160°E–172°30'E) than in the central (175°E–175°W)and eastern (170°W–160°W) TD on Leg 1, but thesame result was not observed on Leg 2. It was likely that largephytoplankton (2–10 and >10 µm fractions) contributedto the high total Chl a standing stock. We suggest that thehigh total Chl a standing stock on Leg 1, in late spring andearly summer, reflects the contribution of the spring bloomin the subarctic region of the northwestern Pacific Ocean. Thedistribution of total Chl a standing stock on Leg 2 was scarcelyaffected by the spring phytoplankton bloom, suggesting thattotal Chl a standing stock is basically nearly uniform in theTD in spring and summer. Moreover, year-to-year variation inthe total Chl a standing stock was observed in the western TDon Leg 1, suggesting that phytoplankton productivity and/orthe timing of the main period of the bloom exhibits interannualvariations.     

Determination of chlorophylls and carotenoids of marine phytoplankton: separation of chlorophyll a from divinylchlorophyll a and zeaxanthin from lutein

A rapid reverse-phase HPLC method is presented for the identificationand quantification of most of the phytoplankton pigments. Thismethod yields the resolution of divinyl-chlorophyll a and chlorophylla, as well as the partial resolution of lutein and zeaxanthin,and of divinyl-chlorophyll b and chlorophyll b. In addition,chlorophylls c_1,2 and c₃ are well resolved. The analysis timefor one sample is 20 mm, which makes this method particularlysuited when large numbers of samples have to be processed.     

HPLC analysis of phytoplankton pigments from Lake Kinneret with special reference to the bloom-forming dinoflagellate Peridinium gatunense (Dinophyceae) and chlorophyll degradatio products

Photosynthetic pigments extracted from the paniculate materialof the water column of Lake Kinneret were studied throughoutthe periods of May 1988-June 1989, and November 1993-November1994, by means of HPLC. The temporal and vertical variationof the pigment suite found agreed with the microscopically determinedphytoplankton record. The regression calculations of taxon-specificbiomass with the corresponding signature pigments suggest thatpigment analysis may be a useful tool for the monitoring ofbloom-forming species, e.g. the dinoflagellate Peridinium gatunenseNygaard. The HPLC pigment analysis permitted the identificationand quantification of chlorophyll degradation products, providingfor the first time information about their composition in LakeKinneret. Chlorophyllide a was the major detectable degradationproduct of chlorophyll a, varying between 1 and 9% of the chlorophylla concentration. Other chlorophyll a derivatives appeared mostlyin minor quantities. Pheophytin a was virtually lacking in allthe samples. Removal rates of pigments, measured by sedimentationtraps, indicated that the degradation of chlorophyll a via chlorophyllidea is a dynamic process that continues during the sedimentationof the phytoplankton particles.     

Temporal and vertical variation of chlorophyll a concentration, phytoplankton photosynthetic activity and light attenuation in Lake Kinneret: possibilities and limitations for simulation by remote sensing

The relationship between chlorophyll a (Chl a) and primary productivity(PP) in the uppermost water layer and the water column-based(0–15 m) integral values of those variables were examinedusing measurements taken in Lake Kinneret (Israel) from 1990to 2003. In 81% of all Chl a profiles examined, the distributionwas fairly uniform within the entire 0–15 m water column,and 12.3% of instances showed a prominent subsurface maximum,when the lake phytoplankton was dominated by the dinoflagellatePeridinium gatunense. Chl a can be reliably estimated by remotesensing techniques in the productive and turbid water of LakeKinneret, since Chl a concentration at surface layers can beextrapolated to the entire water column. Light vertical attenuationcoefficient average for wavelengths from 400 to 700 nm, K_d,ranged from 0.203 to 1.954 m^–1 and showed high degreeof temporal variation. The maximal rate of photosynthetic efficiency,P_B^opt [average 3.16 (±1.50)], ranged from 0.25 to 8.85mg C m^–3 h^–1 mg Chl a^–1. Using measured dataof Chl a, P_B^opt, and light as an input, a simple depth-integratedPP model allowed plausible simulation of PP. However, a lackof correlation between photosynthetic activity and temperature(or other variable with remotely sensed potential) renders theuse of models that require input of photosynthetic efficiencyto calculate integrated PP of little value in the case of productiveand turbid Lake Kinneret.     

CHANGES IN EMISSION SPECTRA OF PHOTOSYNTHETIC PIGMENTS IN VIVO

1. The effects of 3-(4'-chlorophenyl)-1, 1-dimethylurea (CMU)onthe fluorescence of photosynthetic pigments in vivo wereinvestigatedin blue-green, red and brown algae and in isolatedspinach chloroplasts.CMU caused an increase in steady statelevel of fluorescenceof chlorophyll a, but did not influencethe fluorescence ofphycobilins. The spectrum of the fluorescenceincrement hada peak at 685 m/µ and a shoulder at 730–740mµ.These two bands probably arise from chlorophyll a(C_f684) belongingto pigment system II.
2. On excitation of chlorophylla in a red alga, Porphyra yezoensis,a fluorescence band witha peak at 720 mµ was observedbesides a shoulder at 685mµ. The 720 m band is inferredto arise from chlorophylla (probably, C_f-1) in pigment systemI.
3. On addition of CMUto the algal cells, the induction of fluorescencewas modifiedto take a simple time course. The induction wasobserved onlywith respect to the fluorescence of chlorophylla, but not inthe fluorescence of phycobilins. The spectrumof the "transient"fluorescence showed two emission bands ofchlorophyll a at 685mµ and 740 mµ, and was quitesimilar in form tothe spectrum of the CMU-caused increase insteady state fluorescence.
4. These facts were interpreted in terms of the correlation offluorescence of chlorophyll a and the photochemical reactionsof photosynthesis

(Received July 20, 1967; )     

Structural differences between light and heavy rare earth elment binding chlorophylls in naturally grown fern Dicranopteris linearis

Chloroplasts and chlorophylls were isolated from the leaves of Dicranopteris linearis, a natural perennial fern sampled at rare earth element (REE) mining areas in the South-Jiangxi region (southern China). The inductively coupled plasma-mass spectrometry (ICP-MS) results indicated that REEs were present in the chloroplasts and chlorophylls of D. linearis. The in vivo coordination environment of light REE (lanthanum) or heavy REE (yttrium) ions in D. linearis chlorophyll-a was determind by the extended X-ray absorption fine structure (EXAFS). Results revealed that there were eight nitrogen atoms in the first coordination shell of the lanthanum atom, whereas there were four nitrogen atoms in the first coordination shell of yttrium. It was postulated that the lanthanum-chlorophyll-a complex might have a double-layer sandwichlike structure, but yttrium-binding chlorophyll-a might be in a single-layer form. Because the content of REE-binding chlorophylls in D. linearis chlorophylls was very low, it is impossible to obtain structural characteristics of REE-binding chlorophylls by direct analysis of the Fourier transform infrared (FTIR) and ultraviolet (UV)-visible spectra of D. linearis chlorophylls. In order to acquire more structural information of REE-binding chlorophyll-a in D. linearis, lanthanum—and yttrium-chlorophyll-a complexes were in vitro synthesized in acetone solution. Element analyses and EXAFS results indicated that REE ions (lanthanum or yttrium) of REE-chlorophyll-a possessed the same coordination environment whether in vivo or in vitro. The FTIR spectra of the REE-chlorophyll-a complexes indicated that REEs were bound to the porphyrin rings of chlorophylls. UV-visible results showed that the intensity ratios of Soret to the Q-band of REE-chlorophyll-a complexes were higher than those of standard chlorophyll-a and pheophytin-a indicating that REE-chlorophyll-a might have a much stronger ability to absorb the ultraviolet light. The MCD spectrum in the Soret band region of lanthanum-chlorophyll-a showed a special peak, but yttrium-chlorophyll-a did not have this special peak, corresponding well to their double-layer and single-layer structure, respectively. Structural differences between lanthanum—and yttrium-chlorophyll-a might result from the difference in ion radius between yttrium and lanthanum. These data might be useful for understanding of both the properties of REE-chlorophyll-a complexes and the physiological roles of REEs in the hyperaccumulator D. linearis.     

Size and species-specific primary productivity and community structure of phytoplankton in Tokyo Bay

Combined methods of size fractionation and single-cell isolationwere used to investigate the seasonal variation of phytoplanktondynamics in Tokyo Bay with an emphasis on primary productivity.Red tides occurred in Tokyo Bay from spring to autumn; a diatom,Skeletonema costatum, and a raphidophycean, Heterosigma akashiwo,were the most important primary producers. Small diatoms andflagellates, including these species, were dominant and showedrapid changes of phytoplankton community structure within severaldays in summer. The nanoplankton (3–20 µm) fractioncontributed most to chlorophyll a concentration and primaryproductivity during spring to autumn, whereas the microplankton(>20 µm) contribution was remarkable in winter. Picoplankton(<3 µm phytoplankton) remained relatively constantthroughout the year. A significant reverse relationship wasobtained between assimilation rate and chlorophyll a contentfor the total and nanoplankton population; the assimilationrate was high at the initial phase of the bloom, then decreasedto a minimum level at the peak of the bloom. Factors controllingthe reduction of assimilation rates at the peak, and changesin phytoplankton community structure, are discussed.     

OCCURRENCE OF A FAR-RED-ABSORBING PIGMENT (P 715) IN LEAF EXTRACT OF GYNKGO BILOBA

The occasional occurrence of far-red-absorption band in thegreen extract of Gynkgo biloba leaves was noticed. It resultedfrom the conversion of the ordinary red-absorbing form of thechlorophyllous pigments with absorption maximum at 675 mµ(P 675), to the far-red-absorbing form with absorption maximumat 710–715 mµ (P 715). The conversion seems to takeplace in two steps, i.e., first, decrease in thered-absorptionband, and secondly, appearance of the far-red-absorption band.Under some experimental conditions, the latter step occurs onlyafter a certain time lag. The conversion is accompanied by thechangeof chlorophylls a and b, contained in the initial formof the pigment, P 675, to the pheophytins and pheophorbides.The properties of the far-red-absorbing pigment are differentfrom those of other chlorophyllous pigments discovered in otherplant materials. ( Accepted January 29, 1965)     

Photoacoustic Spectroscopy--Leaf Absorption Spectra

Using a relatively recent technique, photoacoustic spectroscopy(PAS), purple pigmentation in leaves of three species of Euphorbiawas characterized as anthocyanin by observing a peak at 545nm. The in vivo chlorophylls of the leaf have a recorded maximumabsorption peak at 675 nm as against 665 nm of the in vitrochlorophylls. The intensity of purple pigmentation in leavesof Euphorbia hirta L., are inversely correlated to the soilmoisture levels, leaf water content and leaf water potentials.The applicability of PAS to biological samples was discussed.     

Detection of Chlorophyll Breakdown Products in the Senescent Leaves of Higher Plants

The determination of intermediary breakdown products of chlorophyllsin senescent leaves of higher plants was performed by high-performanceliquid chromatographic technique that had been newly developedto separate and identify the oxidation products of chlorophylls,in particular monopyrrole derivatives [Suzuki et al. (1999)J. Chromatogr. A 839: 85]. In six plants tested, degradationproducts were detected only in the senescent leaves of plantsincluding barley (Hordeum vulgare), except for radish (Raphanussativus), in which they were found both in pre- and senescentcotyledons. In the senescent cotyledons of barley, three degradationproducts, hematinic acid, methyl ethyl maleimide, and the putativedegraded C-E-ring derivative, methyl vinyl maleimide dialdehyde,were detected. In addition to above three products, methyl vinylmaleimide was also found in both pre- and senescent cotyledonsof radish. These products decreased during senescence with anaccumulation of unknown compound(s), probably degraded monopyrrolederivatives. The degradation process and amounts of breakdownproducts of chlorophylls depend largely on plant species andvary with length of senescence. To conclude, it is likely thatchlorophylls are degraded into low-molecular-weight hydrolyticcompounds through monopyrroles. (Received March 10, 1999; Accepted June 11, 1999)     

Size structures of microplankton biomass and production in Jiaozhou Bay, China

Seasonal investigations of size-fractionated biomass and productionwere carried out from February 1992 to May 1993 in JiaozhouBay, China. Microplankton assemblages were separated into threefractions: pico- (0.7–2 µm), nano- (2–20 µm)and netplankton (20–200 µm). The biomass was measuredas chlorophyll a (Chi a), paniculate organic carbon (POC) andparticipate organic nitrogen (PON). The production was determinedby ¹⁴C and ¹⁵N tracer techniques. The seasonal patterns in biomass,though variable, were characterized by higher values in springand lower values in autumn and summer (for Chi a only). Theseasonal patterns in production, on the other hand, were moreclear with higher values occurring in summer and spring, andlower values occurring in autumn and winter. Averaged over thewhole study period, the respective proportions of total biomassaccounted for by net-, nano- and picoplankton were 26, 45 and29% for Chi a, 32, 33 and 35% for POC, and 26, 32 and 42% forPON. The contributions to total primary production by net-,nano- and picoplankton were 31, 35 and 34%, respectively. Therespective proportions of total NH₄⁺–N uptake accountedfor by net-, nano- and picoplankton were 28, 33 and 39% in thedaytime, and 10, 29 and 61% at night. The respective contributionsto total NO₃^–-N uptake by net-, nano- and picoplanktonwere 37, 40 and 23% in the daytime, and 13, 23 and 64% at night.Some comprehensive ratios, including C/N biomass ratio, Chla/C ratio, C uptake/Chl a ratio, C:N uptake ratio and the f-ratio,were also calculated size separately, and their biological andecological meanings are discussed.