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PubMed1973

Correlation between Chlorophyll and Chlorogenic Acid Content in Tobacco Leaves.

A positive correlation (r = 0.75, P < 0.01) was obtained between chlorophyll and chlorogenic acid content in the seedling leaves of burley and dark tobaccos. The dark tobaccos contained significantly higher concentrations of both constituents than the burleys. Such a correlation also occurred in a cytoplasmic mutant of chlorophyll-variegated tobacco when the green and yellow laminae were compared. In addition, the activity of phenylalanine ammonia-lyase and polyphenol-oxidase was higher in the green lamina than in the yellow tissue, which coincided with quantitative distribution of chlorogenic acid. Chlorophyll deficiency induced by streptomycin in tobacco seedlings resulted in a progressive decrease in chlorogenic acid content. However, an interruption of streptomycin treatment provoked accumulation of the two compounds. Dark-grown seedlings showed an increase in the content of chlorophyll and chlorogenic acid upon illumination. Incorporation of l-phenylalanine-U-(14)C into chlorogenic acid during leaf greening was drastically reduced owing to the presence of phenylpyruvate; the latter compound is a possible by-product of chlorophyll biosynthesis. This phenomenon was also evident with light-grown leaves. Results suggest that in addition to phenylalanine ammonia-lyase as a key enzyme regulating chlorogenic acid biosynthesis, an alternative pathway involving the conversion of phenylpyruvate to cinnamate may be functional in tobacco leaves. This pathway may bear importance as to higher chlorogenic acid content in dark tobaccos than in burleys.

Journal Article↗
PubMed1974

Properties of Protochlorophyllide and Chlorophyll(ide) Holochromes from Etiolated and Greening Leaves.

Protochlorophyllide and chlorophyll(ide) holochromes (Pchl-H and Chl-H) were extracted from dark-grown and greening seedlings with saponin and partly purified by ammonium sulfate fractionation. Sephadex gel filtration in the presence of saponin showed that the photoactive saponin Pchl-H from dark-grown leaves of bean (Phaseolus vulgaris L. cv. Redlands Pioneer) or pea (Pisum sativum L. cv. Greenfeast) has an apparent molecular weight of about 170,000, compared with 51,000 to 75,000 for the saponin Pchl-H from barley (Hordeum vulgare L. cv. Svalöfs Bonus). Photoconversion of saponin Pchl-H from dark-grown barley seedlings yields Chl-H with an absorption maximum at 678 nm, and with no change in apparent molecular weight. Above 0 C, a spectral shift from 678 to 672 nm follows, and a change in apparent molecular weight from about 63,000 to 29,000 is observed.Saponin Chl-H extracted from barley leaves illuminated for 15 minutes has an absorption maximum at 670 nm and an apparent molecular weight greater than 100,000. This chlorophyll holochrome has photosystem I activity and it is eluted together with the cytochromes. Saponin holochrome extracted from barley leaves returned to darkness after a light period, contains chlorophyll(ide) and protochlorophyllide complexes. Gel chromatography yields a complete separation of Chl-H (apparent molecular weight > 100,000) and photoactive Pchl-H (63,000).It is proposed that Chl-H dissociates into a chlorophyll(ide) a carrier protein complex and a photoenzyme, before the incorporation of chlorophyll into the lamellar membrane.Spectrofluorimetry on partially photoconverted preparations of saponin holochrome from barley, bean, and pea gave no indication for resonance energy transfer from protochlorophyllide to chlorophyllide. The saponin holochromes gave high polarization values, in contrast with bean holochrome extracted without the aid of detergents and bean leaves.

Journal Article↗
PubMed1975

Regulation of chlorophyll synthesis in the green alga golenkinia.

Chlorophyll synthesis in Golenkinia is inhibited 10-fold by growth in darkness on acetate or by growth on elevated concentrations of acetate in the light, particularly if the growth medium contains low levels of nitrogen. Glucose has no such inhibitory effect. delta-Aminolevulinic acid, with a maximal effect at 0.01 m, but not its precursors, overrides the inhibitory effect of acetate and darkness, restoring chlorophyll synthesis. Glycine, succinate, and alpha-ketoglutarate, the precursors tested, all enter the cell. Cells forming chlorophyll produce significantly more aminolevulinic acid than do cells becoming bleached, further indicating the important regulatory role of this compound. Cyclic AMP has no effect on chlorophyll synthesis. These results are compared with those obtained studying other algae, and a mechanism relating light and acetate to chlorophyll formation is proposed.

Journal Article↗
PubMed1976

Photosynthesis in trees: organization of chlorophyll and photosynthetic unit size in isolated gymnosperm chloroplasts.

Chloroplasts have been isolated in high yield from several gymnosperms and from two deciduous trees. The organization of chlorophyll in the chloroplasts of these woody species is basically similar to that in angiosperm crop plants and green algae. The tree chloroplasts contain two chlorophyll proteins, the P700-chlorophyll a-protein and the major light-harvesting chlorophyll a/b-protein, the size, spectral characteristics, and function of which are the same as the equivalent complexes previously isolated from other classes of green plants. All the gymnosperms have chlorophyll/P700 ratios (photosynthetic unit sizes) 1.6 to 3.8 times larger than that typically found in crop plants; the deciduous trees have units of intermediary size. The presence of fewer but larger photosynthetic units in the woody species can partially account for their lower photosynthetic rate and explains why their photosynthetic processes saturate at lower light intensities. Chloroplasts of shade needles have large units containing a greater proportion of the light-harvesting chlorophyll a/b-protein than those of sun needles.

Journal Article↗
PubMed1978

Relative Requirements for Magnesium of Protein and Chlorophyll Synthesis in Euglena gracilis.

The relationships among Mg, growth, chlorophyll synthesis, and cytoplasmic polysome content were studied in Euglena gracilis grown in different levels of the metal. At all levels of magnesium from 20 to 1,600 mumolar, both protein and chlorophyll are formed with exponential kinetics. The apparent rates of synthesis and final yields of both components are greater at higher levels of Mg, but the rate of chlorophyll synthesis always exceeds the rate of protein formation; i.e. the most severely deficient cells contain proportionally more chlorophyll than the sufficient cells. Cytoplasmic polysomes isolated from Mg-deficient Euglena are indistinguishable from those isolated from control cells. We conclude that decreased rates of protein synthesis occur prior to and possibly are causal to decreased rates of chlorophyll synthesis, but that the mechanism of this inhibition remains unclear.

Journal Article↗
PubMed1980

Effects of calcium on chlorophyll synthesis and stability in the early phase of greening in cucumber cotyledons.

The effects of calcium on chlorophyll accumulation and its stability in the early phase of greening in cucumber cotyledons were investigated. Chlorophyll accumulation was hardly affected by dark preincubation of cotyledons with 10 millimolar calcium solution, but was inhibited almost completely when 50 or 100 millimolar solution was used. On the other hand, 50 millimolar calcium inhibited delta-aminolevulinic acid formation in the light by only 75%. Calcium had little effect on the lag for initiation of protochlorophyllide(650) regeneration, but slowed down the rate of accumulation of protochlorophyllide(650). In calcium-treated cotyledons, the chlorophyll formed by primary photoconversion was quickly decomposed in the dark. The present results show that calcium inhibited chlorophyll accumulation by inhibiting delta-aminolevulinic acid formation in the light and by stimulating the decomposition of newly formed chlorophyll, both effects being completely prevented by potassium.

Journal Article↗
PubMed1981

White Light Effects on the mRNA for the Light-Harvesting Chlorophyll a/b-Protein in Lemna gibba L. G-3.

Translation products of poly(A) mRNA isolated from Lemna gibba L. G-3 include a major polypeptide of 32,000 daltons which is immunoprecipitated by antiserum to chlorophyll a/b-protein from Chlamydomonas. This 32,000 dalton polypeptide represents a precursor to the light-harvesting chlorophyll a/b-protein of molecular weight 28,000 found in the thylakoid membranes of Lemna gibba. The amount of this translatable mRNA decreases relative to other translatable mRNAs when green plants grown in continuous white light are placed in darkness. This decrease occurs rapidly. The most rapid decline occurs during the first day; after 4 days of darkness, only a low level of this mRNA can be detected by in vitro translation. When the plants are returned to white light there is an increase in the relative level of this mRNA which can be easily detected within two hours. The in vivo synthesis of this protein has been assayed under the different light conditions. The light effects on the in vivo synthesis of the chlorophyll a/b-protein reflect the light effects on the translatable mRNA for the polypeptide. The results indicate that light induced changes in the synthesis, processing, or degradation of chlorophyll a/b-protein mRNA could account for the light-induced changes observed in the effective synthesis rates for the chlorophyll a/b-protein in vivo.

Journal Article↗
PubMed1983

Relation between the Light-Harvesting Chlorophyll a-Protein Complex LHCPa and Photosystem I in the Alga Chlamydobotrys stellata.

The light-harvesting chlorophyll protein system of the alga Chlamydobotrys stellata consists of an as yet uncharacterized algal chlorophyll a-protein, called LHCPa, and a common photosystem II-related chlorophyll a/b-protein, called LHCPb (Brandt, Kaiser-Jarry, Wiessner 1982 Biochim Biophys Acta 679: 404-409). For further characterization, this LHCPa was isolated from the organism by polyacrylamide isoelectrofocusing and reelectrophoresis. It contains only chlorophyll a and has only one apoprotein (32,000 daltons). When separated from autotrophically grown cells, its absorption peak is at 674 nm and its isoelectric point at 5.3. Photoheterotrophic cultivation of the algae shifts the absorption maximum of LHCPa to 679 nm and its isoelectric point to 4.8. This LHCPa is a component of photosystem I particles. In relation to the total chlorophyll a content, the amount of LHCPa is low in autotrophic algae, but increases under photoheterotrophic growth conditions, where the organisms do not have the ability to assimilate CO(2) photosynthetically.

Journal Article↗
PubMed1985

Extinction coefficients of chlorophyll a and B in n,n-dimethylformamide and 80% acetone.

We found inconsistencies in the commonly used data for chlorophyll analysis in 80% acetone. Recently developed extinction coefficients for chlorophyll b in N,N-dimethylformamide (DMF) based on values from 80% acetone are low as a result of these inconsistencies. We determined extinction coefficients of chlorophyll a (Chl a) and chlorophyll b (Chl b) in DMF for wavelengths of 618 to 665 nanometers. The simultaneous equations necessary for quantifying Chl a, Chl b, or total Chl in DMF in the absence of other chlorophyllous pigments are: Chl a = 12.70A(664.5) - 2.79A(647); Chl b = 20.70 A(647) - 4.62A(664.5); total Chl = 17.90A(647) + 8.08A(664.5), where A = absorbance in 1.00 centimeter cuvettes and Chl = milligrams per liter.N,N-Dimethylformamide is a very convenient solvent for Chl extraction since it is effective on intact plant parts and Chl is quite stable in DMF. There was no difference in the amount of Chl extracted when plant tissue was stored for 1 or 3 days at three temperatures, with or without solvent added.

Journal Article↗
PubMed1985

Influence of photosynthesis and chlorophyll synthesis on polypeptide accumulation in greening euglena.

Two-dimensional gel electrophoresis resolves total cellular protein from Euglena gracilis klebs var bacillaris Cori into 640 polypeptides, 79 of which are induced by light exposure. The inhibition of chloroplast translation by streptomycin, the direct inhibition of photosynthesis as well as the indirect inhibition of chlorophyll synthesis by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and the specific inhibition of photosynthesis but not chlorophyll synthesis by DCMU in the presence of 17 millimolar ethanol failed to inhibit the accumulation of 40 polypeptides. These polypeptides appear to be synthesized on cytoplasmic ribosomes and their accumulation is independent of the developmental status of the chloroplast. Streptomycin but not DCMU completely inhibited the accumulation of six polypeptides which are undetectable in mutants lacking chloroplast DNA suggesting that these polypeptides are translated on chloroplast ribosomes. The accumulation of seven polypeptides which are detectable in mutants lacking chloroplast DNA was also inhibited by streptomycin but not by DCMU suggesting that the accumulation of these polypeptides is dependent upon stabilization by a chloroplast translation product. The accumulation of 12 polypeptides was inhibited by streptomycin and by DCMU under conditions in which chlorophyll synthesis was inhibited, but not under conditions in which chlorophyll synthesis was unaffected by DCMU. The inhibition by DCMU of the accumulation of these polypeptides appears to be due to the inhibition of chlorophyll synthesis suggesting that they are components of pigment protein complexes. The accumulation of six polypeptides was inhibited under all conditions in which photosynthesis was inhibited suggesting that the accumulation of these polypeptides is dependent upon a product of photosynthesis.

Journal Article↗
PubMed1986

Accumulation of Chlorophyll, Chloroplastic Proteins, and Thylakoid Membranes during Reversion of Chromoplasts to Chloroplasts in Citrus sinensis Epicarp.

In vitro culture of pericarp segments from fruit of Citrus sinensis (L.) Osbeck cv Valencia was used to determine the temporal sequence in development of chloroplasts from chromoplasts during regreening of the epicarp. Regreening of chromoplasts closely resembled greening of etioplasts, except that regreening proceeded much more slowly. Chlorophyll, the light-harvesting chlorophyll a/b binding protein of photosystem II, the chlorophyll a binding protein of reaction center P-700 of photosystem I, thylakoid membranes, and adenosine triphosphate synthetase were all detected at very low levels in degreened epicarp. All of these increased in parallel during regreening of the epicarp. Ribulose 1,5-bisphosphate carboxylase (RuBPCase) levels were high in degreened epicarp and declined for the first 10 days of culture before reaccumulating in the regreening segments. Light was necessary for the accumulation of all of the chloroplastic components. A lack of exogenous nitrogen did not prevent the accumulation of any chloroplastic component except Ru-BPCase, although accumulation of the other components was reduced. Sucrose at 150 millimolar in media lacking nitrogen markedly inhibited the accumulation of chlorophyll and light-harvesting chlorophyll a/b-protein.

Journal Article↗
PubMed1988

Chlorophyll Expression Varies with Development State in the Temperature-Sensitive ch4 Mutation of Melilotus alba.

The ch4 mutant of sweetclover (Melilotus alba) has previously been demonstrated to be temperature- and photoperiod-sensitive for the accumulation of chlorophyll. Pigment content of ch4 mutant leaves was examined as a function of trifoliolate mass, an index of leaf development. Inhibition of chlorophyll accumulation caused by increased growth temperature or decreased photoperiod can be attenuated during the earliest leaf development stages but is almost complete after the trifoliolates have reached 10 milligrams in size. Once this size is reached, the total amount of chlorophyll per trifoliolate remains constant, and the amount of chlorophyll per gram of leaf decreases as the leaf expands. We have evidence for several other sweetclover mutants with this general phenotype, all with alterations previously determined to be located in different genes as evidenced by complementation following genetic crosses. This mutant phenotype may represent lesions in the chlorophyll biosynthetic pathway or the assembly of the photosynthetic apparatus.

Journal Article↗
PubMed1991

Chlorophyll Fluorescence and Photon Yield of Oxygen Evolution in Iron-Deficient Sugar Beet (Beta vulgaris L.) Leaves.

The response of sugar beet (Beta vulgaris L.) leaves to iron deficiency can be described as consisting of two phases. In the first phase, leaves may lose a large part of their chlorophyll while maintaining a roughly constant efficiency of photosystem II photochemistry; ratios of variable to maximum fluorescence decreased by only 6%, and photon yields of oxygen evolution decreased by 30% when chlorophyll decreased by 70%. In the second phase, when chlorophyll decreased below a threshold level, iron deficiency caused major decreases in the efficiency of photosystem II photochemistry and in the photon yield of oxygen evolution. These decreases in photosystem II photochemical efficiency were found both in plants dark-adapted for 30 minutes and in plants dark-adapted overnight, indicating that photochemical efficiency cannot be repaired in that time scale. Decreases in photosystem II photochemical efficiency and in the photon yield of oxygen evolution were similar when measurements were made (a) with light absorbed by carotenoids and chlorophylls and (b) with light absorbed only by chlorophylls. Leaves of iron-deficient plants exhibited a room temperature fluorescence induction curve with a characteristic intermediate peak I that increases with deficiency symptoms.

Journal Article↗
PubMed1992

Occurrence of Temperature-Sensitive Phenotypic Plasticity in Chlorophyll-Deficient Mutants of Arabidopsis thaliana.

A collection of 75 putative mutants with alterations in leaf pigmentation was visually selected from Arabidopsis thaliana plants (M(2) generation) grown at 26 degrees C from seeds treated with the mutagen ethylmethanesulfonate. Fifty-eight of the plants were found to have chlorophyll contents decreased by at least 10% from the parental Columbia ecotype. These plants were screened for chlorophyll content and the ratio of chlorophyll b/a after growth at 20 or 26 degrees C. Relative to the parental type, a significant number of individuals in which the chlorophyll-deficient phenotype was exacerbated at one of the growth temperatures were identified. We conclude that temperature-sensitive phenotypic plasticity for chlorophyll content is relatively common in mutant populations of higher plants.

Journal Article↗
PubMed2004

Sequence of morphological and physiological events during natural ageing and senescence of a castor bean leaf: sieve tube occlusion and carbohydrate back-up precede chlorophyll degradation.

The development of castor bean (Ricinus communis L. var. sanguineus) leaves from bud break to abscission was studied to determine whether senescence of phloem precedes or follows chlorophyll degradation in the course of natural ageing of leaves. The castor bean leaf blade took 20 days for full expansion and its average life span was 60 days. From the day of full expansion on it suffered a substantial loss in N, a small loss in C, K and P and a gain in Ca, Mg and S. The content of soluble sugars increased with time, paralleled by a decrease of photosynthetic activity. Starch accumulated shortly before chlorophyll breakdown. The amino acid level in the leaves decreased steadily together with nitrate reductase and glutamine synthetase activity. Reactive oxygen species increased and oxidation-protecting compounds decreased during the life span of the leaves. Shortly after full leaf expansion an increasing number of sieve plates showed strong callose depositions when visualized by aniline blue method. At day 40 only half of the sieve tubes appeared functional. Chlorophyll breakdown followed these processes with a time lag of approximately 10 days. The sieve tube sap of ageing leaves had the same sucrose concentrations as young leaves, whereas amino acid concentrations decreased. High levels of reduced ascorbic acid and glutathione together with increasing levels of glutaredoxin indicated oxidative strain during senescence. We speculate that the gradual increase of reactive oxygen species during ageing together with the import of calcium ions lead to the stimulation of callose synthesis in plasmodesmata and sieve plates with the consequence of inhibition of phloem transport leading to carbohydrate back-up in the leaf blade. The latter may finally induce chlorophyll breakdown and, at the end, leaf abscission at the petiole base. Thus phloem blockage would precede and may be causal for chlorophyll degradation in leaf senescence.

Journal Article↗
PubMed1996

The fucoxanthin-chlorophyll proteins from a chromophyte alga are part of a large multigene family: structural and evolutionary relationships to other light harvesting antennae.

A fucoxanthin-chlorophyll protein (FCP) cDNA from the raphidophyte Heterosigma carterae encodes a 210-amino acid polypeptide that has similarity to other FCPs and to the chlorophyll a/b-binding proteins (CABs) of terrestrial plants and green algae. The putative transit sequence has characteristics that resemble a signal sequence. The Heterosigma fcp genes are part of a large multigene family which includes members encoding at least two significantly different polypeptides (Fcp1, Fcp2). Comparison of the FCP sequences to the recently determined three-dimensional structure of the pea LHC II complex indicates that many of the key amino acids thought to participate in the binding of chlorophyll and the formation of complex-stabilizing ionic interactions are well conserved. Phylogenetic analyses of sequences of light-harvesting proteins shows that the FCPs of several chromophyte phyla form a natural group separate from the intrinisic peridinin-chlorophyll proteins (iPCPs) of the dinoflagellates: Although the FCP and CAB genes shared a common ancestor, these lineages diverged from each other prior to the separation of the CAB LHC I and LHC II sequences in the green algae and terrestrial plants.

Amino Acid Sequence↗
PubMed2005

Spatial analysis and eutrophication assessment for chlorophyll a in Taihu Lake.

Spatial structure analysis and kriging analysis have been identified to be useful tools in illustrating the spatial patterns of variables. Taihu Lake is one of the largest fresh water lakes in China, and has suffered serious eutrophication in recent years due to the rapid economic development and growing environmental pollution in the Taihu Catchment. In this paper, spatial structural analysis, kriging interpolation and eutrophication assessment were carried out for chlorophyll a in the lake. Studies show that spherical model could be applied to fit all experimental variograms. Positive nuggets were observed for three directions except NE-SW direction. The variograms show some anisotropy with anisotropic ratio falling within 1.76. The spatial structural patterns of chlorophyll a in the lake were affected by factors such as distribution of pollution sources, water flow and wind. Two-dimensional ordinary block kriging was applied for interpolation process. An eutrophication assessment map was also made based on a water-quality evaluation standard. Results show that the content of chlorophyll a in Taihu Lake was quite high. The whole lake has suffered serious eutrophication. However, the eutrophic situation varied in space. Higher contents of chlorophyll a appeared mainly in the northern part of the lake.

China↗
PubMed1985

A non-fluorescent complex of chlorophyll a with plastocyanin.

A complex between chlorophyll a and plastocyanin has been prepared by dialysis of mixtures of chlorophyll in Triton X-100 micellar solution with the protein. The complex appears to contain no more than one chlorophyll per plastocyanin molecule, and is non-fluorescent, whether the protein is in the oxidized or reduced state. The lack of fluorescence suggests that the chlorophyll is adsorbed very close to the Cu center.

Chlorophyll↗