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enzymic synthesis of the iron-sulfur cluster of spinach ferredoxin.a biologically active spinach ferredoxin was reconstituted from the apoprotein by incubation with catalytic amounts of the sulfurtransferase rhodanese in the presence of thiosulfate, reduced lipoate and ferric ammonium citrate. analytical and spectroscopical features of the reconstituted ferredoxin were identical to those of the native one; yield of the reconstitution reaction was 80%. yields and kinetic parameters of the enzymic and chemical reconstitution were also compared. the higher efficie ...19846430704
spirulina ferredoxin-nadp+ reductase. the complete amino acid sequence.the amino acid sequence of ferredoxin-nadp+ oxidoreductase [ec 1.18.1.2, fnr] from spirulina sp., a blue-green alga, was determined. spirulina ferredoxin-nadp+ oxidoreductase was composed of 294 amino acid residues and the molecular weight of the holoenzyme was 34,135. an apparent homology of the amino(n)-terminal region was found between ferredoxin-nadp+ reductases from spirulina and spinach. we also found some sequence similarities in human erythrocyte glutathione reductase and p-hydroxybenzoa ...19846430889
phylogeny of the 5s ribosomal rna from synechococcus lividus ii: the cyanobacterial/chloroplast 5s rnas form a common structural class.the complete nucleotide sequence of the 5s ribosomal rna from the cyanobacterium synechococcus lividus ii has been determined. the sequence is (sequence in text) this 5s rna has the cyanobacterial- and chloroplast-specific nucleotide insertion between positions 30 and 31 (using the numbering system of the generalized eubacterial 5s rna) and the chloroplast-specific nucleotide-deletion signature between positions 34 and 39. the 5s rna of s. lividus ii has 27 base differences compared with the 5s ...19846443313
examination of protein sequence homologies: i. eleven escherichia coli l7/l12-type ribosomal "a" protein sequences from eubacteria and chloroplast.seven complete and four partial sequences of escherichia coli l7/l12-type ribosomal "a" proteins obtained from various bacteria (e. coli, bacillus subtilis, micrococcus lysodeikticus, rhodopseudomonas spheroides, desulfovibrio vulgaris, streptomyces griseus, bacillus stearothermophilus, clostridium pasteurianum, arthrobacter glacialis, and vibrio costicola) and spinach chloroplast have been reexamined using a computer program that searches for homologous tertiary structures. comparison matrices ...19846443314
isolation and characterization of the cytosolic and chloroplast forms of spinach leaf fructose diphosphate aldolase.two different isoenzymes of fructose-p2 aldolase can be resolved by chromatography of crude spinach leaf extracts on deae-cellulose columns. the acidic isoenzyme comprises about 85% of the total leaf aldolase activity. the two forms differ in primary structure as judged by their distinctive amino acid compositions, tryptic peptide patterns, and immunological properties. only the acidic isoenzyme was detected in extracts of isolated chloroplasts, suggesting that this molecule represents the chlor ...19846420397
2-(4-bromoacetamido)anilino-2-deoxypentitol 1,5-bisphosphate, a new affinity label for ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum. determination of reaction parameters and characterization of an active site peptide.a new affinity label for ribulose bisphosphate carboxylase/oxygenase from rhodospirillum rubrum, 2-(4-bromoacetamido)anilino-2-deoxypentitol 1,5-bisphosphate, has been prepared, reductive amination of ribulose-p2 with p-phenylenediamine in the presence of sodium cyanoborohydride yielded an epimeric mixture which was resolved by chromatography on quaternary aminoethyl-sephadex. subsequent bromoacetylation of the isolated amino bisphosphates gave reagents a and b (ribo and arabino epimers of 2-(4- ...19846421817
temperature dependence of the resonance raman spectra of plastocyanin and azurin between cryogenic and ambient conditions.resonance raman spectra of spinach plastocyanin and pseudomonas aeruginosa azurin were studied as a function of temperature between 10 k and 300 k. the spectra are markedly improved both in signal/noise ratio and in resolution at low temperatures. the assignments of the resonance raman-active vibrations are reinterpreted in view of the number and intensities of peaks observed in the low-temperature spectra. features appear in the low-temperature spectra of azurin that may be due to copper-bound ...19846422471
the shape of ribulose bisphosphate carboxylase/oxygenase in solution as inferred from small angle neutron scattering.small angle neutron scattering of both activated and deactivated hexadecameric ribulose bisphosphate carboxylase/oxygenase from spinach revealed that its structure in solution very closely resembles that determined for the deactivated crystalline enzyme from tobacco (baker, t.s., eisenberg, d., and eiserling, f. (1977) science 196, 293-295). scattering from both forms of the enzyme in h2o most closely fits that expected from a hollow sphere with an outer radius of 56.4 a and inner radius of 14.3 ...19846423629
x-ray diffraction studies on photosystem i fragments from a blue-green alga, anabaena variabilis, and spinach.photosystem i fragments were prepared from thylakoid membranes of a blue-green alga (anabaena variabilis) and spinach by treatment with a detergent, triton x-100. equatorial x-ray diffraction patterns were recorded on films for oriented specimens of thylakoid membranes and photosystem i fragments. the thylakoid membranes and photosystem i fragments gave essentially the same equatorial diffraction patterns in both anabaena variabilis and spinach, indicating that the major x-ray scatterers in thes ...19846425276
cellular fructose-p2 aldolase has a derivatized (blocked) nh2 terminus.fructose-p2 aldolases isolated from vertebrate skeletal muscle have underivatized nh2-terminal proline residues in contrast to most other cytoplasmic proteins which contain alpha-n-acetylated termini. however, if "native" aldolase molecules derived from chicken muscle, rat liver, wheat germ, and the cytosol of spinach leaves are isolated in the presence of phenylmethanesulfonyl fluoride (an inhibitor of serine proteases), they contain blocked and presumably derivatized nh2-terminal residues. whe ...19846693379
protoporphyrinogen oxidation, an enzymatic step in heme and chlorophyll synthesis: partial characterization of the reaction in plant organelles and comparison with mammalian and bacterial systems.high rates of oxidation of protoporphyrinogen to protoporphyrin were demonstrable in etioplasts, chloroplasts, and mitochondria from young barley shoots. much lower rates were observed in chloroplasts from older barley or mature spinach, in mitochondria from potatoes or rat liver, and in membranes from the bacteria escherichia coli and rhodopseudomonas spheroides. the presence of high activity in cells capable of rapid synthesis of large amounts of chlorophyll suggests a role for this activity i ...19846703698
magnesium absorption in human subjects from leafy vegetables, intrinsically labeled with stable 26mg.collards, turnip greens, leaf lettuce, and spinach, grown in nutrient solution so that their mg content was 80 to 90% 26mg, were tested in ambulant male volunteers stabilized on a constant metabolic diet. the freeze-dried vegetables were incorporated in bran muffins in which the vegetables replaced part of the bran. bran muffins without vegetables were consumed for breakfast each day. they were also used as a standard test meal to which the vegetable muffins were compared. all subjects participa ...19846711467
structural differences between [2fe-2s] clusters in spinach ferredoxin and in the "red paramagnetic protein" from clostridium pasteurianum. a resonance raman study.the [2fe-2s] ferredoxin ("red paramagnetic protein", rpp) from c. pasteurianum has been found to be composed of two identical subunits of 10,000 +/- 2 000 daltons, each containing a [2fe-2s] cluster. resonance raman (rr) spectra of rpp have been obtained at 23 degrees k, and compared to those of spinach ferredoxin (sp fd). ten modes of the [2fe-2s] chromophore were observed in the 100-450 cm-1 range. assignments of non fundamental modes in the 500-900 cm-1 range allowed correlations between fund ...19846712673
nucleotide sequences of chloroplast 5s ribosomal rna from cell suspension cultures of the liverworts marchantia polymorpha and jungermannia subulata.the nucleotide sequences of chloroplast 5s rrnas from cell suspension cultures of the liverworts marchantia polymorpha and jungermannia subulata were determined. their nucleotide sequences, 119 nucleotides long, were highly homologous to each other (96% identity) and had high homology with those from chloroplast 5s rrnas of two higher plants, tobacco (92% identity) and spinach (92-91% identity), but less homology (87-85% identity) with that from a lower plant, the fern dryopteris acuminata.19846739292
[effect of metalaxyl on the synthesis of rna, dna and protein in phytophthora nicotianae].metalaxyl is used to control diseases caused by fungi of the order of the perenosporales. we investigated the action of this fungicid eon nucleic acid and protein synthesis in liquid cultures of phytophthora nicotianae. the uptake of 32p, 3h-uridine, 3h-thymidine and 14c-leucine as precursors of nuclei acid and protein synthesis by the mycelium was not inhibited by metalaxyl. rna synthesis as indicated by 3h-uridine incorporation was strongly inhibited (about 80%) by 0.5 micrograms/ml of metalax ...19846741170
[nitrate content in the soils and vegetable crops in the villages of one district].the authors determine the content of nitrates in soil samples and the vegetables grown on them (lettuce, spinach, onion, garlic) via sensitive spectrophotometric methods with phenodisulphonic acid and reduction with cadmium column. the lowest nitrates content was established in the soil samples and vegetables grown by aic, followed by the private arms, and the highest - in the green-horse vegetables and soil samples, owing mainly to the technology of production.19846483820
the primary structure of spinach acyl carrier protein.acyl carrier protein (acp) from spinach leaves has been purified to homogeneity by high-performance liquid chromatography with an anion-exchange column. the amino acid sequence of one major acp in spinach leaves, acp-i, has been determined by automated edman degradation. it consists of the following 82 amino acids: (sequence in text). sequencing of the intact polypeptide provided data for the first 57 residues. cleavage of the succinylated acp with cnbr at met-46, followed by sequencing of the f ...19846486822
the effect of hypolipidemic drugs on plant lipid metabolism.the effect of hypolipidemic drugs, wy14643 and dh990, on plant lipid metabolism has been studied. the total incorporation of [14c]acetate into lipids was inhibited by addition of both drugs to aged potato (solanum tuberosum) tuber discs, spinach (spinacia oleracea) leaves, and spinach chloroplasts, while the incorporation in chlorella vulgaris cells was affected only by dh990. moreover, dh990 inhibited the incorporation of 14c-labeled fatty acids into phosphatidylcholine and phosphatidylethanola ...19846486826
absorption kinetics of oxalate from oxalate-rich food in man.the absorption of oxalate was investigated in a healthy subject after ingestion of oxalate-rich meals (spinach and rhubarb) with and without addition of 14c-labeled oxalic acid and calcium oxalate, and after oxalate-free meals with addition of nonlabeled sodium oxalate and calcium oxalate. under these conditions, calcium oxalate was absorbed to the same extent as soluble oxalate; only a small percentage (2.4 +/- 0.7) of the total oxalate load was absorbed. significant oxalate absorption occurred ...19846496379
sequence organization of a pea chloroplast dna gene coding for a 34,500-dalton protein.a gene (pgii), which codes for a 34.5-kilodalton protein, has been isolated and cloned from pea chloroplast dna. the production of its 1.2-kilobase mrna is photodependent. the direction of transcription has been determined, the site of initiation of transcription has been found, and an in vitro protein product has been produced. the gene, including the 5' and 3'-flanking regions, has been sequenced. it shows ca. 95% homology to the photosystem ii thylakoid membrane protein, photogene 32, from sp ...19846513932
chromatographic separation of extruded iron-sulfur cores from the apoproteins of clostridium pasteurianum and spinach ferredoxins in aqueous triton x-100/urea.iron-sulfur core extrusions from spinach [( 2fe-2s]) and clostridium pasteurianum (2[4fe-4s]) ferredoxins in aqueous triton x-100/urea containing excess benzenethiol yield quantitatively [fensn(sph)4]2- with n = 2 and n = 4, respectively. the iron-sulfur cluster can be separated from the corresponding apoprotein by rapid passage of the extrusion mixture over a small anaerobic column of whatman de-52 anion-exchange cellulose. essentially quantitative recovery of [fensn (sph)4]2- is achieved in th ...19846517316
thylakoid membranes: the translational site of chloroplast dna-regulated thylakoid polypeptides.stromal ribosomes and those bound to thylakoid membranes were prepared from intact spinach chloroplasts which were purified on percoll gradients. the products of read-out translation of these ribosomes supplemented with an escherichia coli extract were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. striking similarity was found between the polypeptides labeled in the read-out translation of the chloroplastic ribosomes and those synthesized in isolated chloroplasts. among ...19846517602
unscheduled dna synthesis in human leucocytes after a fish (amine source) meal with or without salad (nitrite source).increased unscheduled dna synthesis (uds) was observed previously in leucocytes from human volunteers after various meals containing nitrite from cured meats and vegetables. to explore further the role of ingested nitrite, uds response was measured in human leucocytes after a meal of bread, butter and cod fish alone (amine source) or bread, butter and cod fish plus a salad of lettuce, radish and spinach (nitrite source). a cross-over design was used so that all subjects (10 male, 10 female) were ...19846533054
survey of fresh vegetables for nematodes, amoebae, and salmonella.contamination by nematodes, amoebae, and bacteria of the genus salmonella was estimated in a 2-year survey of salad vegetables obtained from wholesale and retail sources. the vegetables examined were cucumbers, cabbage, lettuce, celery, carrots, radishes, tomatoes, mushrooms, cauliflower, and spinach. nematode eggs and larvae were recovered by the nacconol-ether centrifugation method. some nematode eggs were identified as parasitic ascaris sp.; the majority of larval nematodes were thought to be ...19846540260
adaptation of plants to atmospheric pollutants.man-made air pollutants are a recent phenomenon in the evolutionary experience of plants and animals although natural air pollutants from volcanic eruptions, forest fires and dust storms have accompanied evolution for geological eras. plants have responded to increasing concentrations of such pollutants as sulphur dioxide, fluorides, photochemical oxidants and acid rain at the community, species, population and individual levels. the lichens and bryophytes have shown particularly dramatic change ...19846559120
effect of dietary fiber on a guinea pig intestinal anaerobe, bacteroides ovatus.the purpose of this study was to determine the effect of fibrous plant components on the growth of intestinal bacteria. an anaerobe was isolated from the guinea pig cecum and identified as bacteroides ovatus. the organism was grown anaerobically in two types of media and shown to require hemin or protoporphyrin ix. treatment of the media with water-insoluble fractions of alfalfa, cabbage, spinach or wheat bran inhibited growth of the culture. inhibition occurred whether the residue remained in t ...19846319647
cadmium - a complex environmental problem. part ii. cadmium in sludges used as fertilizer.in intensively populated countries efficient sewage treatment is essential to protect river quality. an inevitable by-product is sewage sludge which has to be disposed of safely and economically. utilisation of sludge as a fertilizer of agricultural land is the most economic disposal route for inland sewage-treatment works and also benefits farmers by providing a cheap manure. much of the cadmium in wastewater is concentrated into sludge which consequently contains higher concentrations of cadmi ...19846321225
ophiobolin a. a natural product inhibitor of calmodulin.ophiobolin a, a fungal metabolite and a phytotoxin which can stimulate the net leakage of electrolytes and glucose from maize seedling roots (tipton, c. l., paulsen, p. v., and betts, r. e. (1977) plant physiol. 59, 907-910) was found to be a potent inhibitor of calmodulin-activated cyclic nucleotide phosphodiesterase. the physiologically less active analogue, 3-anhydro-ophiobolin a, was found to be less inhibitory than ophiobolin a in the phosphodiesterase assay. the direct interaction between ...19846321479
relationship of components in wheat bran and spinach to iron bioavailability in the anemic rat.components found in wheat bran and spinach were evaluated as to their affect on the bioavailability of ferrous iron (i.e., feso4) by using the criteria of hemoglobin regeneration in anemic rats. the relative biological value (rbv) of iron in wheat bran and spinach (feso4 = 100%) were determined to be 124 and 53%, respectively. control diets with graded levels of feso4 did not contain dietary fiber (i.e., cellulose). adding cellulose (1.74%) or phytic acid (0.66%) at levels contained in the wheat ...19846321704
sequence homology and structural similarity between cytochrome b of mitochondrial complex iii and the chloroplast b6-f complex: position of the cytochrome b hemes in the membrane.the amino acid sequences of cytochrome b of complex iii from five different mitochondrial sources (human, bovine, mouse, yeast, and aspergillus nidulans) and the chloroplast cytochrome b6 from spinach show a high degree of homology. calculation of the distribution of hydrophobic residues with a "hydropathy" function that is conserved in this family of proteins implies that the membrane-folding pattern of the 42-kilodalton (kda) mitochondrial cytochromes involves 8-9 membrane-spanning domains. th ...19846322162
comparison of ribosomal proteins of chloroplast from spinach and of e. coli.a comparison of ribosomal proteins from escherichia coli and from chloroplasts of spinach was made using two separate methods: electrophoretic migration and immunochemical cross-reaction between blotted e. coli ribosomal proteins and chloroplast ribosomal subunits antisera. it is shown that l2 from e. coli (e-l2) and l4 from chloroplasts (cs-l4) comigrated and that e-l2 immunologically cross-reacted with the isolated cs-l4 antibody. co-migration was observed for three additional couples of 50s r ...19846361495
acylation of plant acyl carrier proteins by acyl-acyl carrier protein synthetase from escherichia coli.the acyl-acyl carrier protein synthetase from escherichia coli has been examined for its ability to specifically acylate acyl carrier protein (acp) from higher plants in order to develop an assay for plant acp, and to prepare labeled acyl-acp of plant origin. it was found that the e. coli enzyme was able to acylate acp from spinach, soybean, avocado, corn, and several other plants. the acylation was very specific because, in crude extracts of spinach leaves where acp represented approximately 0. ...19846370139
a novel, general radioimmunoassay for acyl carrier proteins.a radioimmunoassay (ria) for acyl carrier proteins (acp) is described that is based on the competitive binding between [3h]acyl-acp and unlabeled acp of the same species. the radiolabeled antigen, [3h]palmitoyl-acp, is enzymatically synthesized by escherichia coli acyl-acp synthetase. because acyl-acp synthetase can specifically radiolabel acp in crude extracts from several plant sources, the use of this enzyme to prepare [3h]acyl-acp obviates the need for pure preparations of each acp. preparat ...19846372545
thioredoxin system of the photosynthetic anaerobe chromatium vinosum.chromatium vinosum, an anaerobic photosynthetic purple sulfur bacterium, resembles aerobic bacterial cells in that it has an nadp-thioredoxin system composed of a single thioredoxin which is reduced by nadph via nadp-thioredoxin reductase. both protein components were purified to homogeneity, and some of their properties were determined. chromatium vinosum thioredoxin was slightly larger than other bacterial thioredoxins (13 versus 12 kilodaltons) but was similar in its specificity (ability to a ...19846373736
computed spatial homology between the l12 protein of chloroplast ribosome and 1.7 a structure of escherichia coli l12 domain.a computer-graphic model of the tertiary structure of a functional domain in an organelle ribosomal protein was generated using the amino acid sequence of chloroplast ribosomal protein l12 from spinach (bartsch, kimura and subramanian, proc. natl. acad. sci. usa 79, 6871-6875, 1982) and 1.7 a resolution coordinates of the e. coli l12 c-terminal fragment crystal (leijonmarck, eriksson and liljas, nature 286, 824-826, 1980). a comparison between the model and the experimentally derived structure s ...19846383397
copper facilitated chemiluminescence from the sulfhydryl proteins: yeast alcohol dehydrogenase, spinach ferredoxin and metallothionein.this paper describes a copper mediated formation of active oxygen, presumably o2, from the sulfhydryl proteins, yeast alcohol dehydrogenase spinach ferredoxin and rabbit liver metallothionein which, on the addition of cyanide in the presence of acetaldehyde, displays as a chemiluminescence. these studies may provide some insights into the mechanisms of copper toxicity and provide a sensitive assay for monitoring the presence of sulfhydryl groups.19846391488
reconstitution of 50 s ribosomal subunits from bacillus stearothermophilus with 5 s rna from spinach chloroplasts and low-mr rna from mitochondria of locusta migratoria and bovine liver.reconstitution experiments with 50 s ribosomal subunits from bacillus stearothermophilus demonstrate that spinach chloroplast 5 s rrna can be incorporated into the bacterial ribosome and yield biologically active particles, thereby establishing the eubacterial nature of chloroplast 5 s rrna. in contrast, mitochondria from locusta migratoria or bovine liver do not appear to contain discrete, low-mr rnas, which can replace 5 s rrna in the functional reconstitution of b. stearothermophilus ribosome ...19846201395
manganese proteins isolated from spinach thylakoid membranes and their role in o2 evolution. i. a 56 kilodalton managnese-containing protein, a probable component of the coupling factor enzyme.the binding of endogenous manganese (mn) to proteins released from spinach grana-thylakoid membranes by 2% cholate detergent or by osmotic shock is investigated. a mixture of 15-20 proteins is released by cholate and has been separated by isoelectric focusing in a sucrose gradient or by chromatofocusing. mn coelutes with several proteins, but is lost upon dialysis. a dramatic redistribution of this mn occurs in proteins released by osmotic shock in the presence of hydrophobic and hydrophilic oxi ...19846234021
human exposure to nickel.in order of abundance in the earth's crust, nickel ranks as the 24th element and has been detected in different media in all parts of the biosphere. thus, humans are constantly exposed to this ubiquitous element, though in variable amounts. the average natural nickel exposure from food in the past has probably been somewhat, but not much, below current levels. nickel is a useful metal, particularly in various alloys, in batteries and in nickel-plating. nickel compounds are used especially as cat ...19846241927
a new epr signal associated with photosystem 1 of algal and plant photosynthesis.a new low temperature electron paramagnetic resonance (epr) signal with a g-value of 1.97 was found in photosystem-1 particles from a blue-green alga, anacystis nidulans, illuminated at room temperature. a similar signal was also found in spinach photosystem-1 particles treated with thiophenol to decrease interference from a signal due to center a. in the dark, the signal appeared only when the anacystis particles were at redox potentials lower than -0.5 volts where centers a and b were also red ...19846327659
distinct reduction of nitrofurans and metronidazole to free radical metabolites by tritrichomonas foetus hydrogenosomal and cytosolic enzymes.anaerobic tritrichomonas foetus hydrogenosomes supplemented with pyruvate and coa effectively reduce nitrofurans and metronidazole to their respective anion free radicals. addition of purified ferredoxins from clostridium pasteurianum or spinacia oleracea to these preparations causes a great stimulation of metronidazole reduction, but does not affect nitrofuran reduction. a similar stimulatory effect of ferredoxin on metronidazole reduction, but not on nitrofuran reduction, is observed in incuba ...19846330106
isolation and characterization of calmodulin from the motile green alga chlamydomonas reinhardtii.calmodulin, a calcium-binding protein with no known enzymatic activity but multiple, in vitro effector activities, has been purified to apparent homogeneity from the unicellular green alga chlamydomonas reinhardtii and compared to calmodulin from vertebrates and higher plants. chlamydomonas calmodulin was characterized in terms of electrophoretic mobility, amino acid composition, limited amino acid sequence analysis, immunoreactivity, and phosphodiesterase activation. chlamydomonas calmodulin ha ...19846322690
anion and divalent cation activation of phosphoglycolate phosphatase from leaves.phosphoglycolate (p-glycolate) phosphatase was purified 223-fold from spinach leaves by (nh4)2so4 fractionation, deae-cellulose chromatography, and sephadex g-200 chromatography. the partially purified enzyme had a broad ph optimum between 5.6 and 8.0 and was specific for the hydrolysis of p-glycolate with a km (p-glycolate) of 26 microm. the enzyme was activated by divalent cations including mg2+, co2+, mn2+, and zn2+, and by anions including cl-, br-, no-3, and hcoo-. neither anions nor divale ...19846322692
oxetin, a new antimetabolite from an actinomycete. fermentation, isolation, structure and biological activity.a new amino acid-antimetabolite, oxetin, was isolated from a fermentation broth of a streptomyces sp. om-2317, a soil isolate. the chemical structure was elucidated as (2r,3s)-3-amino-2-oxetane carboxylic acid by analysis of the spectral data and by x-ray diffraction methods. the antibiotic is the first natural product possessing an oxetane ring. certain microorganisms were inhibited by oxetin only when cultivated in minimal media. the inhibitory action was reversed by several amino acids such a ...19846150928
junctions of the large single copy region and the inverted repeats in spinacia oleracea and nicotiana debneyi chloroplast dna: sequence of the genes for trnahis and the ribosomal proteins s19 and l2.this work describes the organization, at the nucleotide sequence level, of genes flanking the junctions of the large single copy regions and the inverted repeats of spinacia oleracea (spinach) and nicotiana debneyi chloroplast dnas. in both genomes, trnh1, the gene for trna-his(gug) is located at the extremity of the large single copy region 3' to psba, the gene for the 35 kd photosystem 2 protein. both psba and trnh1 are transcribed towards the inverted repeat. in spinach, the first 48 codons o ...19846089120
isolation and characterization of thioredoxin f from the filamentous cyanobacterium, anabaena sp. 7119.two thioredoxin fractions had previously been reported to occur in anabaena 7119 by buchanan and co-workers (yee, b. c., dela torre, a., crawford, n. a., lara, c., carlson, d. e., and buchanan, b. b. (1981) arch. microbiol. 130, 14-18). these proteins were detected by their ability to activate spinach fructose-1,6-bisphosphatase (fru-p2-ase). the partially purified proteins resembled similar thioredoxins found in spinach chloroplasts and were designated thioredoxin f (tf) for the fraction most e ...19846094540
structure of the spinach chloroplast genes for the d2 and 44 kd reaction-centre proteins of photosystem ii and for trnaser (uga).we have determined the sequence of the spinach (spinacia oleracea) chloroplast genes for the photosystem ii proteins, d2 and the 44 kd reaction-centre, chlorophyll a-binding protein, and for trnaser (uga). the 3' end of the d2 gene overlaps the first 50 bp of the 5' end of the gene for the 44 kd protein. northern rna hybridization analysis indicates the two genes are cotranscribed into a single 3.5 kb rna. the predicted molecular weight of the 353-residue d2 protein is 39536 and that of the 473- ...19846096808
purification of peroxisomes and mitochondria from spinach leaf by percoll gradient centrifugation.a procedure was developed to purify simultaneously peroxisomes and mitochondria from spinach (spinacia oleracea l.) leaf under isoosmotic and low viscosity conditions. this method involved differential centrifugation and density gradient centrifugation on four layers of percoll. chlorophyll-free preparations of highly intact and active organelles were obtained and cross-contamination was negligible. both organelles were stable for several hours, even if they remained in percoll. purified mitocho ...198416663685
reactivation by chloride of hill activity in heat- and tris-treated thylakoid membranes from beta vulgaris.hill activity (photoreduction of 2,6,dichlorophenol indophenol) of heat inactivated (40°c, 3 min) and tris-washed (0.8m, ph 8.3) thylakoids of beta vulgaris (beet-spinach) was partially restored if they were incubated with 150 mm mgcl2 prior to the assay. mg(no3)2 or mgso4 were unable to restore this activity. the extent of this reactivation was dependent upon the degree of inactivation by heating and upon the composition of the isolation and the resuspension buffer used during the heat treatmen ...198424458606
effects of cu deficiency on photosynthetic electron transport.the role of copper (cu) in photosynthetic electron transport was explored by using cu deficiency in sugar beet as an experimental approach. copper influenced electron transport at two sites in addition to plastocyanin. under mild deficiency (0.84 nmol of cu per cm(2) of leaf area), electron transport between the two photosystems (ps) is inhibited but not electron transport within ps i or ps ii measured separately. the chlorophyll/plastoquinone ratio was normal in cu-deficient plants. however, th ...198416593455
inhibition of 3-phosphoglycerate-dependent o(2) evolution by phosphoenolpyruvate in c(4) mesophyll chloroplasts of digitaria sanguinalis (l.) scop.the effects of phosphoenolpyruvate (pep), inorganic phosphate (pi), and atp on 3-phosphoglycerate (pga)-dependent o(2) evolution by chloroplasts of digitaria sanguinalis (l.) scop. (crabgrass) were evaluated relative to possible mechanisms of pep transport by the c(4) mesophyll chloroplast. crude and percoll purified chloroplast preparations exhibited rates of pga-dependent o(2) evolution in the range of 90 to 135 micromoles o(2) per milligram chlorophyll per hour, and up to 180 micromoles o(2) ...198416663911
fusion of spinach mesophyll protoplasts with carrot root parenchyma protoplasts and the effect on spinach chloroplasts.mesophyll protoplasts of spinach (spinacia oleracea l.) have been fused, using polyethylene glycol, with root parenchyma protoplasts of carrot (daucus carota l.) to enable studies of spinach chloroplasts in a foreign cytoplasm. after 24 h culture, electron microscopy of the fused protoplasts showed many intact chloroplasts, but some chloroplasts were completely disrupted, showing loss of chloroplast envelope and stroma. spinach protoplasts showed normal chloroplast structure 24 h after peg treat ...198423196088
pyruvate-derived amino acids in spinach chloroplasts : synthesis and regulation during photosynthetic carbon metabolism.a probable carbon flow from the calvin cycle to branched chain amino acids and lipids via phosphoenolpyruvate (pep) and pyruvate was examined in spinach (spinacia oleracea) chloroplasts. the interpendence of metabolic pathways in and outside chloroplasts as well as product and feedback inhibition were studied. it was shown that alanine, aromatic, and small amounts of branched chain amino acids were formed from bicarbonate in purified intact chloroplasts. addition of pep only favored formation of ...198416663866
conversion of glycerate to serine in intact spinach leaf peroxisomes.intact spinach (spinacia oleracea l.) leaf peroxisomes converted glycerate to serine in the presence of nad and alanine. the reaction proceeded optimally at ph9. addition of oxaloacetate or alpha-ketoglutarate plus aspartate enhanced the conversion about three-fold. alteration of the concentration of one of the reaction components, consisting of 2 mm glycerate, 0.2 mm nad, 0.5 mm oxaloacetate, and 2 mm alanine, revealed half-saturation constants of 0.45 mm for glycerate, 0.06 mm for nad, 0.02 mm ...19846435526
control of photosynthetic sucrose synthesis by fructose 2,6-bisphosphate : iii. properties of the cytosolic fructose 1,6-bisphosphatase.the cytosolic fructose 1,6-bisphosphatase from spinach (spinacia oleracea u.s. hybrid 424) leaves has been partially purified and its response to fructose 2,6-bisphosphate, amp, and fructose 1,6-bisphosphate studied, using concentrations present in the cytosol during photosynthesis. in the presence of fructose 2,6-bisphosphate, the substrate saturation kinetics for fructose 1,6-bisphosphate are sigmoidal, with half-maximal activity being attained in 0.1 to 1 millimolar concentration range. the i ...198416663666
control of photosynthetic sucrose synthesis by fructose 2,6-bisphosphate : ii. partitioning between sucrose and starch.the role of fructose 2,6 bisphosphate in partitioning of photosynthate between sucrose and starch has been studied in spinach (spinacia oleracea u.s. hybrid 424). spinach leaf material was pretreated to alter the sucrose content, so that the rate of starch synthesis could be varied. the level of fructose 2,6-bisphosphate and other metabolites was then related to the accumulation of sucrose and the rate of starch synthesis. the results show that fructose 2,6-bisphosphate is involved in a sequence ...198416663665
control of photosynthetic sucrose synthesis by fructose 2,6-bisphosphate : i. coordination of co(2) fixation and sucrose synthesis.a mechanism is proposed for a feed-forward control of photosynthetic sucrose synthesis, which allows withdrawal of carbon from the chloroplast for sucrose synthesis to be coordinated with the rate of carbon fixation. (a) decreasing the rate of photosynthesis of spinach (spinacia oleracea, u.s. hybrid 424) leaf discs by limiting light intensities or co(2) concentrations leads to a 2-to 4-fold increase in fructose 2,6-bisphosphate. (b) this increase can be accounted for by lower concentrations of ...198416663664
measurement of subcellular metabolite levels in leaves by fractionation of freeze-stopped material in nonaqueous media.this paper describes a technique for measuring the in vivo metabolite levels in the chloroplast stroma, the cytosol, and the vacuole of spinach (spinacia oleracea u.s.a. hybrid 424) leaves. spinach leaves were freeze stopped and the frozen tissue was ground and lyophilized. the dry material was homogenized by sonication in a mixture of carbon tetrachloride and heptane, and fractionated by density gradient centrifugation. measurements of the activity of marker enzymes in various subcellular compa ...198416663663
light-induced nuclear synthesis of spinach chloroplast fructose-1,6-bisphosphatase.etiolated spinach (spinacia oleracea l. var winter giant) seedlings show a residual photosynthetic fructose-1,6-bisphosphatase activity, which sharply rises under illumination. this increase in activity is due to a light-induced de novo synthesis, as it has been demonstrated by enzyme labeling experiments with (2)h(2)o and [(35)s]methionine. the rise of bisphosphatase activity under illumination is strongly inhibited by cycloheximide, but not by the 70s ribosome inhibitor lincocin, which shows t ...198416663662
the co2/o 2 specificity of ribulose 1,5-bisphosphate carboxylase/oxygenase : dependence on ribulosebisphosphate concentration, ph and temperature.the substrate specificity factor, v cko/vokc, of spinach (spinacia oleracea l.) ribulose 1,5-bisphosphate carboxylase/oxygenase was determined at ribulosebisphosphate concentrations between 0.63 and 200 μm, at ph values between 7.4 and 8.9, and at temperatures in the range of 5° c to 40° c. the co2/o2 specificity was the same at all ribulosebisphosphate concentrations and largely independent of ph. with increasing temperature, the specificity decreased from values of about 160 at 5° c to about 5 ...198424253719
a rapid reverse phase evaporation method for the reconstitution of uncharged thylakoid membrane lipids that resist hydration.comparison of several lipid reconstitution methods showed that they were not equally efficient at transferring the predominant thylakoid lipid, monogalactosyldiglyceride (mg), to the aqueous phase. we report a reverse phase evaporation method that employs freon 11 as a lipid solvent and is capable of successfully hydrating mg in spinach (spinacia oleracea l.) at room temperature within minutes. using this method it is possible to force an equal weight mixture of mg and digalactosyldiglyceride in ...198416663653
photosynthetic carbon metabolism in leaves and isolated chloroplasts from spinach plants grown under short and intermediate photosynthetic periods.responses of foliar and isolated intact chloroplast photosynthetic carbon metabolism observed in spinach (spinacia oleracea cv wisconsin bloomsdale) plants exposed to a shortened photosynthetic period (7-hour light/17-hour dark cycle), were used as probes to examine in vivo metabolic factors that exerted rate determination on photosynthesis (ps) and on starch synthesis. compared with control plants propagated continuously on a 12-hour light/12-hour dark cycle, 14 to 15 days were required, subseq ...198416663634
the uptake of gibberellin a1 by suspension-cultured spinacia oleracea cells has a carrier-mediated component.the kinetics of the uptake of [(3)h]gibberellin a1 (ga1) by light- and dark-grown suspension-cultured cells of spinacia oleracea (spinach) have been studied. use of nonradioactive ga1 and gibberellic acid (ga3) show that the uptake has a saturable and a nonsaturable component. the nonsaturable component increases as the ph is lowered at a fixed concentration of [(3)h]ga1 and is probably caused by non-mediated diffusion of the uncharged protonated species of ga1. the saturable component is not th ...198424258671
characteristics of light-dependent inorganic carbon uptake by isolated spinach chloroplasts.the light-dependent accumulation of radioactively labeled inorganic carbon in isolated spinach (spinacia oleracea l.) chloroplasts was determined by silicone oil filtering centrifugation. intact chloroplasts, dark-incubated 60 seconds at ph 7.6 and 23 degrees c with 0.5 millimolar sodium bicarbonate, contained 0.5 to 1.0 millimolar internal inorganic carbon. the stromal pool of inorganic carbon increased 5- to 7-fold after 2 to 3 minutes of light. the saturated internal bicarbonate concentration ...198416663542
purification and properties of spinach leaf debranching enzyme.starch debranching enzyme was purified from intact spinach (spinacia oleracea l. cv vital) chloroplasts and from a spinach leaf extract using affinity chromatography on sepharose 6b-bound cycloheptaamylose (schardinger beta-dextrin). the enzyme from both sources was homogeneous upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. spinach leaf debranching enzyme appears to consist of a single polypeptide chain, since the molecular weight of the native protein (110,000 daltons) was not ...198416663522
de novo maltotriose biosynthesis from the reducing end by spinacia oleracea l. chloroplasts.the distribution of (14)c in the various glucose residues of maltotriose was studied as a function of time of photosynthesis of isolated chloroplasts of spinach (spinacia oleracea l.) using (14)co(2). the distribution of label showed that the reducing-end glucose residue was labeled first and the label subsequently distributed to the second and third glucose residues at approximately equal rates.a mechanism for the distribution of label and the synthesis of maltotriose from the reducing end is p ...198416663512
freeze-fracture ultrastructure of thylakoid membranes in chloroplasts from manganese-deficient plants.leaves from spinach (spinacia oleracea l. cv hybrid 102) plants grown in mn-deficient nutrient solution were characterized by chlorosis, lowered chlorophyll a/b ratio and reduced electron transport. there were characteristic changes in room temperature fluorescence induction kinetics with increased initial yield (f(o)) and decreased variable fluorescence (f(v)). the fluorescence yield after the maximum fell rapidly to a level below f(o). the shape of the rise from f(o) to the maximum was altered ...198416663491
subcellular localization of triacylglycerol synthesis in spinach leaves.the subcellular location of diacylglycerol acyltransferase (ec 2.3.1.20) in spinach leaves (spinacia oleracea l. cv. longstanding bloomsdale) was determined after sucrose-gradient centrifugation of tissue homogenates. enzyme activity was associated primarily with gradient fractions containing oil bodies and intact chloroplasts. gradient fractions enriched with the endoplasmic reticulum contained insignificant levels of diacylglycerol acyltransferase activity. on the basis of chlorophyll, diacylg ...198427520324
evidence for control of carbon partitioning by fructose 2,6-bisphosphate in spinach leaves.excision of spinach (spinacia oleracea l.) leaves had no effect on photosynthetic rates, but altered normal carbon partitioning to favor increased formation of starch and decreased formation of sucrose. the changes were evident within 2 hours after excision. concurrently, leaf fructose-2,6-bisphosphate content increased about 5-fold (from 0.1 to 0.5 nanomoles per gram fresh weight). the activities of sucrose-p synthase and cytoplasmic fructose 1,6-bisphosphatase in leaf extracts remained constan ...198416663440
short term acclimation of spinach to high temperatures: effect on chlorophyll fluorescence at 293 and 77 kelvin in intact leaves.using intact leaves of spinacia oleracea (l.), reversible temperature-induced changes in chlorophyll fluorescence emitted at room temperature and at 77k were studied. interpretation of fluorescence at 77k was largely facilitated by developing a new method to minimize reabsorption artifacts (;diluted leaf-powder'). leaves of plants grown at 15 to 20 degrees c were exposed for several hours to different temperatures. upon incubation at 35 degrees c in the dark or in the light, the following change ...198416663430
spinach pyruvate kinase isoforms : partial purification and regulatory properties.pyruvate kinase from spinach (spinacea oleracea l.) leaves consists of two isoforms, separable by blue agarose chromatography. both isoforms share similar ph profiles and substrate and alternate nucleotide k(m) values. in addition, both isoforms are inhibited by oxalate and atp and activated by amp. the isoforms differ in their response to three key metabolites; citrate, aspartate, and glutamate. the first isoform is similar to previously reported plant pyruvate kinases in its sensitivity to cit ...198416663425
interference by ddt and cyclodiene types of insecticides with chloroplast-associated reactions.the effects of ddt, some of its analogs, and selected cyclodiene insecticides on isolated spinach (spinacea oleracea l.) thylakoids were identified, characterized, and compared to responses induced by selected herbicides. except for endrin, the insecticides inhibited light-induced electron transport, altered chlorophyll fluorescence transients, and competitively displaced [14c]atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], a known photosystem ii inhibitor, from the membranes. ...19846697419
nine introns with conserved boundary sequences in the euglena gracilis chloroplast ribulose-1,5-bisphosphate carboxylase gene.the single, chloroplast encoded gene for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcl) from euglena gracilis is found to contain nine intervening sequences. the intervening sequences were identified by heteroduplex analysis between euglena rbcl and the non-intron-containing rbcl from spinacea oleracea, by electron microscopy of euglena rbcl dna-mrna hybrids, and by cloning, restriction endonuclease analysis, and partial dna sequencing. the identification, locus, and ...19846319030
inhibited light activation of fructose and sedoheptulose bisphosphatase in spinach chloroplasts exposed to osmotic stress.the light activation of fructose-1,6-bisphosphatase (ec 3.1.3.11) and sedoheptulose-1,7-bisphosphatase (ec 3.1.3.37) was inhibited in isolated intact spinach (spinacia oleracea l.) chloroplasts exposed to reduced osmotic potentials. decreases in the velocity and magnitude of light activation correlated with the overall reduction in co2 fixation rates. responses of osmotically stressed chloroplasts to both varying ph and exogeous dihydroxyacetone phosphate (dhap) or 3-phosphoglycerete (pga) were ...198424258369
thylakoid membrane stability in drought-tolerant and drought-sensitive plants.the stress stability of membranes from two drought-tolerant plants (craterostigma plantagineum andceterach officinarum) was compared with that of a drought-sensitive plant (spinacia oleracea) in model experiments. thylakoids from these plants were exposed to excessive sugar or salt concentrations or to freezing. all stresses caused loss of membrane function as indicated by the loss of cyclic photophosphorylation or the inability of the membranes to maintain a large proton gradient in the light. ...198424253553
temperature dependence of energy-transducing functions and inhibitor sensitivity in chloroplasts.a comparative analysis of the temperature dependence of energy-transducing reactions in spinach (spinacia oleracea) chloroplasts and their sensitivity for uncouplers and energy-transfer inhibitors at different temperatures is presented. arrhenius plots reveal two groups of transitions, around 19 degrees c and around 12 degrees c. activities that show transitions around 19 degrees c include linear electron flow from water to ferricyanide, its coupled photophosphorylation, the dark-release of the ...198416663374
characterization of calcium fluxes across the envelope of intact spinach chloroplasts.calcium fluxes across the envelope of intact spinach chloroplasts (spinacia oleracea l.) in the light and in the dark were investigated using the metallochromic indicator arsenazo iii. light induces ca(2+) influx into chloroplasts. the action spectrum of light-induced ca(2+) influx and the inhibitory effect of 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (dcmu) indicate an involement of photosynthetic electron transport in this process. the driving force for light-induced ca(2+) influx is most like ...198524241617
the effect of low osmotic potential on nitrite reduction in intact spinach chloroplasts.the effect of water stress (reduced osmotic potential) on photosynthetic nitrite reduction was investigated using intact, isolated spinach (spinacia oleracea) chloroplasts. nitrite-dependent o(2) evolution was inhibited 39% at -29.5 bars osmotic potential, relative to a control at -11 bars. in the presence of an uncoupler of photophosphorylation this inhibition was not seen. reduced osmotic potential did not inhibit either methyl viologen reduction or photosynthetic o(2) reduction. these results ...198516664429
effect of triacontanol on chlamydomonas: ii. specific activity of ribulose-bisphosphate carboxylase/oxygenase, ribulose-bisphosphate concentration, and characteristics of photorespiration.increased photosynthetic co(2) assimilation by chlamydomonas reinhardtii cells treated with triacontanol (tria) was not due to changes in glycolate excretion, co(2) compensation point, or the sensitivity of photosynthetic co(2) assimilation to o(2). kinetic analysis of tria-treated cells showed that the increase in photosynthetic co(2) assimilation was a result of an increase in the apparent v(max) for intact cells. the total activity of ribulose-p(2) carboxylase/oxygenase was higher in cell lys ...198516664415
stromal protein phosphorylation in spinach (spinacia oleracea) chloroplasts.when intact spinach chloroplasts were supplied with [32p]pi, stromal protein phosphorylation was found to occur in the dark. on illumination the thylakoid protein kinase was activated and the amount of label found in thylakoid proteins quickly exceeded that incorporated into stromal protein, such that the latter was found to account for only 10-15% of the total radioactivity bound to chloroplast proteins after 5 min illumination. the rate of phosphorylation of stromal polypeptides was unchanged ...19854062895
photoinhibition of photosynthesis under anaerobic conditions studied with leaves and chloroplasts of spinacia oleracea l.the role of oxygen in the photoinactivation of the photosynthetic apparatus of spinacia oleracea l. was investigated. moderate irradiation (1200 μmol photons m(-2)s(-1)) of spinach leaves in an atmosphere of pure nitrogen caused strong inhibition of subsequently measured net co2 assimilation, whereas considerably less photoinhibition was observed in the presence of low partial pressures (10-20 mbar) of o2. the decrease in activity caused by anaerobiosis in the light was not based on stomatal clo ...198524241150
metabolite levels in the stroma of spinach chloroplasts exposed to osmotic stress: effects of the ph of the medium and exogenous dihydroxyacetone phosphate.the levels of stromal photosynthetic intermediates were measured in isolated intact spinach (spinacia oleracea l.) chloroplasts exposed to reduced osmotic potentials. stressed chloroplasts showed slower rates of metabolite accumulation upon illumination than controls. relative to other metabolites sedoheptulose-1,7-bisphosphate (sbp) and fructose-1,6-bisphosphate (fbp) accumulated in the stroma in the stressed treatments. under these conditions 3-phosphoglycerate (3-pga) efflux to the medium was ...198524241148
effect of temperature on the co2/o 2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase and the rate of respiration in the light : estimates from gas-exchange measurements on spinach.responses of the rate of net co2 assimilation (a) to the intercellular partial pressure of co2 (p i ) were measured on intact spinach (spinacia oleracea l.) leaves at different irradiances. these responses were analysed to find the value of p i at which the rate of photosynthetic co2 uptake equalled that of photorespiratory co2 evolution. at this co2 partial pressure (denoted г), net rate of co2 assimilation was negative, indicating that there was non-photorespiratory co2 evolution in the light. ...198524241146
photoinhibition of photosynthesis in broken chloroplasts as a function of electron transfer rates during light treatment.photoinhibition was studied in osmotically broken chloroplasts isolated from spinach leaves (spinacia oleracea l.). both whole chain electron transport (measured as ferricyanide-dependent o(2) evolution in the presence of nh(4)cl) and photosystem ii activity (measured as o(2) evolution in the presence of either silicomolybdate plus 3-(3,4-diphenyl)-1,1 dimethylurea or parabenzoquinone) showed similar decreases in activity in response to a photoinhibitory treatment (8 minutes of high light given ...198516664315
monoclonal antibodies to a higher-plant nitrate reductase: differential inhibition of enzyme activities.a set of monoclonal antibodies has been raised against nadh-nitrate reductase (nr; ec 1.6.6.1) from spinach (spinacea oleracea l.) leaves. antibodies were screened by enzyme-linked immunosorbent assay and by their ability to inhibit various activities of the enzyme. the six monoclonals selected (afrc mac 74 to 79) are all gamma globulins; four (mac 74 to 77) inhibit all terminal donating activities (nadh-nr; flavin mononucleotide, reduced form (fmnh2)-nr; and methyl viologen, reduced form (mv)-n ...198524240965
isolation of photosystem i complexes from octyl glucoside/sodium dodecyl sulfate solubilized spinach thylakoids : characterization and reconstitution into liposomes.we have used the nonionic detergent octyl-beta-d-glucopyranoside in combination with sodium dodecyl sulfate to isolate two novel photosystem i (psi) complexes from spinach (spinacea oleracea l.) thylakoid membranes. these complexes have been characterized as to their spectral properties, content of psi reaction center chlorophyll p(700), and protein composition. psi-b, purified from solubilized membranes by sucrose density gradient centrifugation, is a putative native psi complex. psi-b contains ...198516664291
association of fe-s center(s) with the large subunit(s) of photosystem i particles.treatment of photosystem i particles from spinach (spinacia oleracea) with dodecyl sulfate destroyed the protein-bound fe-s centers and converted some of the acid-labile sulfide to zero-valence sulfur which remained covalently bound to the proteins. when the proteins were resolved by gel-permeation chromatography or by polyacrylamide gel electrophoresis in the presence of dodecyl sulfate, a considerable amount of zero-valence sulfur was associated with the large molecular weight polypeptide(s) ( ...19852995329
an electron transport system in maize roots for reactions of glutamate synthase and nitrite reductase : physiological and immunochemical properties of the electron carrier and pyridine nucleotide reductase.a non-heme iron containing protein which bears an antigenic similarity to ferredoxin from spinach leaves (spinacia oleracea l.) has been identified in extracts prepared from young roots of maize (zea mays l., hybrid w64a x w182e). the ferredoxin-like root electron carrier could substitute for ferredoxin in a cytochrome c reduction system in which pyridine nucleotide (nadph) reduces the root electron carrier in a reaction catalyzed by ferredoxin-nadp(+) reductase (ec 1.6.7.1) from spinach leaves. ...198516664248
altered gene expression during cold acclimation of spinach.exposure of spinach (spinacia oleracea l.) plants to a constant 5 degrees c induced a greater tolerance to extracellular freezing. the metabolic basis of this cold acclimation response in plants is not understood. in this study we tested the hypothesis that cold acclimation derives from altered gene transcription. we found that exposure of plants to low temperature resulted in a rapid and stable change in the translatable poly(a)+ rna populations extracted from leaves, as determined by a cell-fr ...19853858842
development of cytosol and chloroplast aldolases during germination of spinach seeds.the total activity of aldolase (ec 4.1.2.13) and the activities of cytosol and chloroplast aldolase were determined in seeds, cotyledons, primary leaves and secondary leaves of spinach (spinacia oleracea l., cv. monopa) during germination. total aldolase activity in cotyledons increased from low levels to a low maximum in the dark after one week and to a high maximum in white light after three to four weeks and declined thereafter. the activity in primary and secondary leaves started to rise str ...198524249508
potentiel intracellulaire du mésophylle d'épinard (spinacia oleracea l. cv. nobel) en relation avec la lumière et l'induction florale.using glass microelectrodes we studied (in spinach, a long-day plant) the characteristics of the intracellular potential of mesophyll cells as well as its response towards light, in particular during the transfer of the plant to an inductive photoperiod (transfer from short day to continuous photoperiod). when 20 minutes treatments of alternating white light (2 minutes) and darkness (2 minutes) are provided every 2 hours (during the photo-or nyctoperiod), the amplitude of the bioelectrical respo ...198523196180
inhibition of photosynthetic reactions by light : a study with isolated spinach chloroplasts.illumination of isolated intact chloroplasts of spinacia oleracea l. for 10 min with 850 w m(-2) red light in the absence of substrate levels of bicarbonate caused severe inhibition of subsequently measured photosynthetic activities. the capacity of co2-dependent o2 evolution and of non-cyclic electron transport were impaired to similar degrees. this photoinactivation was prevented by addition of bicarbonate which allowed normal carbon metabolism to proceed during preillumination. photoinhibitio ...198524249342
abscisic acid accumulation in spinach leaf slices in the presence of penetrating and nonpenetrating solutes.abscisic acid (aba) accumulated in detached, wilted leaves of spinach (spinacia oleracea l. cv savoy hybrid 612) and reached a maximum level within 3 to 4 hours. the increase in aba over that found in detached turgid leaves was approximately 10-fold. the effects of water stress could be mimicked by the use of thin slices of spinach leaves incubated in the presence of 0.6 molar mannitol, a compound which causes plasmolysis (loss of turgor). about equal amounts of aba were found both in the leaf s ...198516664022
photosynthesis involvement in the mechanism of action of diphenyl ether herbicides.photosynthesis is not required for the toxicity of diphenyl ether herbicides, nor are chloroplast thylakoids the primary site of diphenyl ether herbicide activity. isolated spinach (spinacia oleracea l.) chloroplast fragments produced malonyl dialdehyde, indicating lipid peroxidation, when paraquat (1,1'-dimethyl-4,4'-bipyridinium ion) or diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] were added to the medium, but no malonyl dialdehyde was produced when chloroplast fragments were treated with ...198516664206
physical and genetic mapping of safflower chloroplast dna : location of psba, rbcl, atpa and rrna.a physical map of safflower (carthamus tinctorius l.) chloroplast dna has been generated using sali, psti, kpni and hindiii restriction endonucleases. the circular plastid genome (151 kbp) has the usual inverted repeat. heterologous probes containing psba, rbcl, atpa or rrna structural genes mapped colinearly with spinach and other chloroplast genomes.198524310941
construction and mapping of safflower chloroplast dna recombinants and location of selected gene markers.dna was isolated and purified from chloroplasts of safflower (carthamus tinctorius l.), digested with hindiii restriction endonuclease, and ligated into the hindiii site of the plasmid puc9. recombinant dnas were isolated from ampicillin resistant white colonies which grew in the presence of the appropriate indicator, digested with hindiii, and then identified by comparison of agarose gel electrophoretic mobilities. hindiii digests of chloroplast dna were used as a standard. such recombinants we ...198524253119
betaine synthesis in chenopods: localization in chloroplasts.plants from several families (chenopodiaceae, gramineae, compositae) accumulate betaine (glycine betaine) in response to salt or water stress via the pathway: choline --> betainal (betaine aldehyde) --> betaine. betaine accumulation is probably a metabolic adaptation to stress. intact protoplasts from leaves of spinach (spinacia oleracea) oxidized [(14)c]choline to betainal and betaine, as did protoplast lysates. upon differential centrifugation, the [(14)c]choline-oxidizing activity of lysates ...198516593569
kinetics of reduction of clostridium pasteurianum rubredoxin by laser photoreduced spinach ferredoxin:nadp+ reductase and free flavins. electron transfer within a protein-protein complex.the kinetics of reduction of oxidized clostridium pasteurianum rubredoxin (rdox) by free flavin semiquinones generated by the laser flash photolysis technique and by spinach ferredoxin:nadp+ reductase (fnr) semiquinone (also produced by flavin semiquinone reduction) have been investigated under anaerobic conditions. 5-deazariboflavin semiquinone (5-drf) rapidly reduces oxidized rubredoxin (rdox) (k = 3.0 x 10(8) m-1 s-1) and oxidized ferredoxin:nadp+ reductase (fnrox) to the semiquinone level (k ...19853968079
a reappraisal of leukocyte dehydroascorbate reductase.dehydroascorbate reductase (glutathione:dehydroascorbate oxidoreductase, ec 1.8.5.1) activity was determined in human leukocyte homogenates using a direct spectrophotometric assay. despite previous studies, using a less sensitive coupled assay, which reported that this enzyme was present in leukocytes, we found that neither neutrophil nor chronic lymphocytic leukemia lymphocyte extracts had detectable activity. furthermore, when the product was quantitated by hplc, protein-dependent generation c ...19853978119
isolation and characterization of safflower (carthamus tinctorius l.) chloroplast dna.safflower (carthamus tinctorius l.) chloroplasts were isolated and purified with the aid of commercially available nylon mesh, differential centrifugation, and dnase i treatment. these chloroplasts were free of nuclei as determined by light microscopy of aceto orcein stained preparations, and similar to those observed by electron microscopy in spinach and many other higher plants, being bounded by a double membrane layer and characterized by the presence of a lamellar system surrounded by embedd ...19853982399
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