Publications

dark-adapted spinach thylakoid protein heterogeneity offers insights into the photosystem ii repair cycle.	in higher plants, thylakoid membrane protein complexes show lateral heterogeneity in their distribution: photosystem (ps) ii complexes are mostly located in grana stacks, whereas psi and adenosine triphosphate (atp) synthase are mostly found in the stroma-exposed thylakoids. however, recent research has revealed strong dynamics in distribution of photosystems and their light harvesting antenna along the thylakoid membrane. here, the dark-adapted spinach (spinacia oleracea l.) thylakoid network w ...	2014	24296034
inhibition of escherichia coli o157:h7 and salmonella enterica on spinach and identification of antimicrobial substances produced by a commercial lactic acid bacteria food safety intervention.	the microbiological safety of fresh produce is of concern for the u.s. food supply. members of the lactic acid bacteria (lab) have been reported to antagonize pathogens by competing for nutrients and by secretion of substances with antimicrobial activity, including organic acids, peroxides, and antimicrobial polypeptides. the objectives of this research were to: (i) determine the capacity of a commercial lab food antimicrobial to inhibit escherichia coli o157:h7 and salmonella enterica on spinac ...	2014	24290643
identification of novel antimicrobial resistance genes from microbiota on retail spinach.	drug resistance genes and their mobile genetic elements are frequently identified from environmental saprophytic organisms. it is widely accepted that the use of antibiotics in animal husbandry selects for drug resistant microorganisms, which are then spread from the farm environment to humans through the consumption of contaminated food products. we wished to identify novel drug resistance genes from microbial communities on retail food products. here, we chose to study the microbial communitie ...	2013	24289541
synthesis and biological evaluation of 2-hydroxy-3-[(2-aryloxyethyl)amino]propyl 4-[(alkoxycarbonyl)amino]benzoates.	a series of twenty substituted 2-hydroxy-3-[(2-aryloxyethyl)amino]propyl 4-[(alkoxycarbonyl)amino]benzoates were prepared and characterized. as similar compounds have been described as potential antimycobacterials, primary in vitro screening of the synthesized carbamates was also performed against two mycobacterial species. 2-hydroxy-3-[2-(2,6-dimethoxyphenoxy)ethylamino]-propyl 4-(butoxycarbonylamino)benzoate hydrochloride, 2-hydroxy-3-[2-(4-methoxyphenoxy)ethylamino]-propyl 4-(butoxycarbonylam ...	2013	24288475
fascioliasis and intestinal parasitoses affecting schoolchildren in atlixco, puebla state, mexico: epidemiology and treatment with nitazoxanide.	the atlixco municipality, puebla state, at a mean altitude of 1840 m, was selected for a study of fasciola hepatica infection in schoolchildren in mexico. this area presents permanent water collections continuously receiving thaw water from popocatepetl volcano (5426 m altitude) through the community supply channels, conforming an epidemiological scenario similar to those known in hyperendemic areas of andean countries.	2013	24278492
identification of an escherichia coli s1-like protein in the spinach chloroplast ribosome.	antibodies directed against e. coli ribosomal protein s1 were used in immunoblotting assays to search for an s1-like protein in the ribosome of spinach chloroplast. an immunological cross-reaction was reproducibly detected on the blots and inhibition experiments have demonstrated its specificity. the chloroplastic ribosomal protein which has epitopes common to antigenic determinants of the e. coli protein s1 was identified as being protein s2/s3.	1988	24277593
transcription study of the genes encoded in the region of the junction between the large single copy and the inverted repeat a of spinach chloroplast dna.	the expression of the psba, trnh-gug and rps19' genes from spinach chloroplasts, coding respectively for the 32 kda protein, the trna(his) (gug), and the putative ribosomal protein cs19', has been studied by cloning, northern hybridization and 3' and 5' s1 mapping experiments.it is demonstrated that the putative transcription termination signal of the psba gene does not function as a rho-independent terminator of transcription in e. coli, whatever its orientation.evidence is presented suggesting ...	1988	24277592
chlorella chloroplast dna sequence containing a gene for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase and a part of a possible gene for the β' subunit of rna polymerase.	the sequence of a 2782 bp fragment of the chloroplast genome of chlorella ellipsoidea has been determined. the region includes the entire gene (rbcl) for the large subunit (ls) of ribulose-1,5-bisphosphate carboxylase/oxygenase and a sequence (rpoc-like) similar to part of the gene for the subunit of e. coli rna polymerase which is oriented in same direction as rbcl. the arrangement is rpoc-like - 446 bp - rbcl. the rbcl gene codes for a polypeptide of 475 amino acids whose sequence shows 88% ho ...	1988	24277518
glutamate and serine as competing donors for amination of glyoxylate in leaf peroxisomes.	when provided with glycollate, peroxisomal extracts of leaves of spinach beet (beta vulgaris l. cv.) converted l-serine and l-glutamate to hydroxypyruvate and 2-oxoglutarate respectively. when approximately saturating concentrations of each of these amino acids were incubated separately with glycollate, the utilization of serine was greater than that of glutamate. the utilization of glutamate was substantially reduced by the presence of relatively low concentrations of serine in the reaction mix ...	1981	24276826
metabolism and decarboxylation of glycollate and serine in leaf peroxisomes.	the linked utilization of glycollate and l-serine has been studied in peroxisomal preparations from leaves of spinach beet (beta vulgaris l.). the generation of glycine from glycollate was found to be balanced by the production of hydroxypyruvate from serine and similarly by 2-oxoglutarate when l-glutamate was substituted for l-serine. in the presence of l-malate and catalytic quantities of nad(+), about 40% of the hydroxypyruvate was converted further to glycerate, whereas with substrate quanti ...	1981	24276825
restriction endonuclease cleavage site map of chloroplast dna from oenothera parviflora (euoenothera plastome iv).	1) more than 50 cleavage sites produced by the restriction endonucleases sal i, pst i, kpn i, sma i and eco ri have been physically mapped on the 47 μm circular dna molecule of the euoenothera plastome iv. this plastome (= plastid genome) is considered to be the phylogenetically oldest of the subsection. 2) the dna molecule is segmentally organized into four regions represented by a large duplicated sequence in inverted orientation whose copies are separated by two single-copy segments. the sing ...	1981	24276512
characterization of maltose biosynthesis from α-d-glucose-1-phosphate in spinacia oleracea. l.	the de novo synthesis of maltose in spinach (spinacia oleracea l.) was shown to be catalyzed by a maltose synthase, which converts two molecules of α-d-glucose-1-phosphate (α-g1p) (km 1.5 mmol l(-1)) to maltose and 2 orthophosphate (pi). this enzyme was purified 203-fold by fractionated ammonium sulfate precipitation and by column chromatography on sepharose 6b. the addition of α-g1p (15 mmol l(-1)) to the isolation buffer is required to stabilize the enzyme activity during the extraction and pu ...	1982	24275923
transformation of arsenic species during in vitro gastrointestinal digestion of vegetables.	arsenic is an element widely distributed in the environment, and the diet is the main source of arsenic exposure for most people. however, many of the processes related to steps before intestinal absorption are unknown. this study evaluates the effect of in vitro gastrointestinal digestion on pentavalent arsenic forms [as(v), mma(v), dma(v)] present in various vegetables (garlic, broccoli, asparagus, spinach) after soaking or boiling in aqueous solutions of these species. the results showed that ...	2013	24274313
expression of an active spinach acyl carrier protein-i/protein-a gene fusion.	a synthetic gene encoding spinach acyl carrier protein i (acp-i) was fused to a gene encoding the fc-binding portion of staphylococcal protein a. this gene fusion, under the control of the λpr promoter, was expressed at high levels in escherichia coli producing a 42 kda fusion protein. this fusion protein was phosphopantethenylated in e. coli. in vitro the acp portion of the fusion protein was able to participate in acyl acp synthetase reactions, plant malonyl-coa:acp transacylase (mct) reaction ...	1989	24272721
the reactivation of nitrate reductase from spinach (spinacea oleracea l.) inactivated by nadh and cyanide: effects of peroxidase and associated systems.	nitrate reductase of spinach (spinacea oleracea l.) leaves which had been inactivated in vitro by treatment with nadh and cyanide, was reactivated by incubation with oxidant systems and measured as fmnh2-dependent activity. ferricyanide, a purely chemical oxidant, produced rapid maximal reactivation (100%) which was 90% complete in less than 3 min. reactivation occurred slowly and less completely (30-75% in 30 or 60 min) when the enzyme was incubated with pure horseradish peroxidase alone, depen ...	1982	24272572
carbohydrate and carbon metabolite accumulation responses in leaves of ozone tolerant and ozone susceptible spinach plants after acute ozone exposure.	the objective of this study was to determine whether exposure of plants to ozone (o3) increased the foliar levels of glucose, glucose sources, e.g., sucrose and starch, and glucose-6-phosphate (g6p), because in leaf cells, glucose is the precursor of the antioxidant, l-ascorbate, and glucose-6-phosphate is a source of nadph needed to support antioxidant capacity. a further objective was to establish whether the response of increased levels of glucose, sucrose, starch and g6p in leaves could be c ...	1996	24271929
the properties of transketolase from photosynthetic tissue.	transketolase (e.c. 2.2.1.1.) has been partially purified from wheat (triticum aestivum, cv. sappo) and spinach (spinacia oleracea) leaves. the fully-active enzyme is a tetramer of relative molecular mass (mr) of 150 kmr requiring thiamin pyrophosphate for maximal activity, and dissociating into a 74 kmr dimer in its absence or in dilute solution. the chloroplastic transketolase (over 75% of the cellular total) is magnesium-stimulated but the cytosolic form is magnesium-insensitive. both chlorop ...	1982	24271866
a comparative flash-photolysis study of electron transfer from pea and spinach plastocyanins to spinach photosystem 1. a reaction involving a rate-limiting conformational change.	two mutants of plastocyanin have been constructed by site-directed mutagenesis in spinach and pea to elucidate the binding and electron transfer properties between plastocyanin and spinach photosystem 1. the conserved, surface-exposed tyr-83 has been replaced by phenylalanine and leucine in plastocyanin from both species and the proteins have been expressed in escherichia coli. the reaction mechanism of electron transfer from plastocyanins to photooxidized p700 in photosystem 1 has been studied ...	1996	24271818
purification and identification of the violaxanthin deepoxidase as a 43 kda protein.	violaxanthin deepoxidase (vde) has been purified from spinach (spinacia oleracea) leaves. the purification included differential sonication of thylakoid membranes, differential (nh4)2so4 fractionation, gel filtration chromatography and finally either hydrophobic interaction chromatography or anion exchange chromatography. a total purification of more than 5000-fold compared to the original thylakoids enabled the identification of a 43 kda protein as the vde, in contrast to earlier reported molec ...	1996	24271609
chimaeric cp47 mutants of the cyanobacterium synechocystis sp. pcc 6803 carrying spinach sequences: construction and function.	chimaeric mutants of the cyanobacterium synechocystis sp. pcc 6803 have been generated carrying part or all of the spinach psbb gene, encoding cp47 (one of the chlorophyll-binding core antenna proteins in photosystem ii). the mutant in which the entire psbb gene had been replaced by the homologous gene from spinach was an obligate photoheterotroph and lacked photosystem ii complexes in its thylakoid membranes. however, this strain could be transformed with plasmids carrying selected regions of s ...	1996	24271295
molecular characterization of two glutathione peroxidase genes of panax ginseng and their expression analysis against environmental stresses.	glutathione peroxidases (gpxs) are a group of enzymes that protect cells against oxidative damage generated by reactive oxygen species (ros). gpx catalyzes the reduction of hydrogen peroxide (h2o2) or organic hydroperoxides to water or alcohols by reduced glutathione. the presence of gpxs in plants has been reported by several groups, but the roles of individual members of this family in a single plant species have not been studied. two gpx cdnas were isolated and characterized from the embryoge ...	2014	24269671
in-vitro degradation of starch granules isolated from spinach chloroplasts.	the initial reactions of transitory starch degradation in spinacia oleracea l. were investigated using an in-vitro system composed of native chloroplast starch granules, purified chloroplast and non-chloroplast forms of phosphorylase (ec 2.4.1.1) from spinach leaves, and α-amylase (ec 3.2.1.1) isolated from bacillus subtilis. starch degradation was followed by measuring the release of soluble glucans, by determining phosphorylase activity, and by an electron-microscopic evaluation following deep ...	1983	24264852
ribulose 1,5-bisphosphate carboxylase and phosphoribulokinase in prochloron.	cell-free extracts of prochloron didemni were assayed for ribulose 1,5-bisphosphate (rubp) carboxylase (ec 4.1.1.39) and phosphoribulokinase (ec 2.7.1.19), two key enzymes in the reductive pentose-phosphate cycle. in an rubp-dependent reaction, the production of two molecules of 3-phosphoglycerate per molecule of co2 fixed was shown. phosphoribulokinase activity was demonstrated by the production of adp from ribulose 5-phosphate (ru5p) and atp and by measurement of atp-, ru5p-dependent (14)co2 f ...	1983	24264746
calmodulin-dependent and independent nad kinase activities from cytoplasmic and chloroplastic fractions of spinach (spinacia oleracea l.).	nad kinase activity has been found in a soluble, cytoplasmic fraction and in the chloroplasts prepared from green spinach leaves. a small amount of both the cytoplasmic and the chloroplastic nad kinase activities was retained on a calmodulin-sepharose affinity column. the cytoplasmic nad kinase eluted from the affinity column was found to be enhanced by calmodulin in a ca(2+)-dependent manner. the chloroplastic enzyme which is located exclusively in the stroma and not in the envelope and thylako ...	1982	24259024
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 ...	1984	24258671
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 ...	1984	24258369
pyridine nucleotides and redox-charge evolution during the induction of flowering in spinach leaves.	in the long-day plant spinacia oleracea changes in the pool size of pyridine nucleotides have been followed under different photoperiodic conditions. in short days (vegetative state), the dark and light phases of the cycle are characterized by specific reciprocal changes in nad and nadp pool sizes. as a consequence, the ratios of nadh/nad+nadh and nadph/nadp+nadph, which are respectively considered to represent the catabolic and anabolic state of metabolism, also show a characteristic pattern. u ...	1983	24258176
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 ...	1984	24253719
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. ...	1984	24253553
gene expression in cytokinin-and light-mediated plastogenesis of cucurbita cotyledons: ribulose-1,5-bisphosphate carboxylase/oxygenase.	the effects of a cytokinin (n(6)-benzyladenine, ba) and light on plastogenesis have been studied in detached cucurbita cotyledons using the key enzyme of photosynthetic co2 fixation, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubpcase), as an example of a coordinated program of plastid and nucleo-cytoplasmic gene expression. treatment of etiolated cotyledons with either ba in darkness or in light or light alone results in a marked and correlated stimulation of enzyme activity, quantity and ...	1984	24253161
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 ...	1985	24253119
spectrophotometric determination of cu(2+) and monitoring of hg(2+) and ni(2+) in some iranian vegetables using 6-(2-naphthyl)-2, 3-dihydro-as-triazine-3-thione.	recently, 6-(2-naphthyl)-2, 3-dihydro-as-triazine-3-thione (ndtt) was synthesized in laboratory and used successfully for the spectrophotometric determination of nanogram levels of cu(2+) in aqueous solution. this reagent forms a specific red complex with cu(2+) ions after the extraction by chloroform at alkaline ph. the absorption of the complex in the uv region (313 nm) is about 8 times as strong as in the visible one (510 nm). mercury and nickel ions form yellow complexes with ndtt under the ...	2013	24250566
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 ...	1985	24249508
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 ...	1985	24249342
copy numbers of chloroplast and nuclear genomes are proportional in mature mesophyll cells of triticum and aegilops species.	the possibility of estimating the proportion of chloroplast dna (ctdna) and nuclear dna (ndna) in nucleic-acid extracts by selective digestion with the methylation-sensitive restriction enzyme psti, was tested using leaf extracts from spinacia oleracea and triticum aestivum. values of ctdna as percentage ndna were estimated to be 14.58%±0.56 (se) in s. oleracea leaves and 4.97%±0.36 (se) in t. aestivum leaves. these estimates agree well with those already reported for the same type of leaf mater ...	1986	24241861
initiation and characterization of a cotton (gossypium hirsutum l.) photoautotrophic cell suspension culture.	a heterotrophic cotton (gossypium hirsutum l. cv. stoneville 825) cell suspension culture was adapted to grow photoautotrophically. after two years in continuous photoautotrophic culture at 5% co2 (balance air), the maximum growth rate of the photoautotrophic cell line was a 400% fresh weight increase in eight days. the chl concentration was approximately 500 μg per g fresh weight.elevated co2 (1%-5%) was required for culture growth, while the ambient air of the culture room (600 to 700 ul co2 1 ...	1988	24241763
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 ...	1985	24241617
effects of temperature at constant air dew point on leaf carboxylation efficiency and co2 compensation point of different leaf types.	the effect of temperature on photosynthesis at constant water-vapor pressure in the air was investigated using two sclerophyll species, arbutus unedo and quercus suber, and one mesophytic species, spinacia oleracea. photosynthesis and transpiration were measured over a range of temperatures, 20-39° c. the external concentration of co2 was varied from 340 μbar to near co2 compensation. the initial slope (carboxylation efficiency, ce) of the photosynthetic response to intercellular co2 concentrati ...	1985	24241315
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 ...	1985	24241150
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 ...	1985	24241148
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. ...	1985	24241146
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 ...	1985	24240965
α-1,4-glucan phosphorylase forms from leaves of spinach (spinacia oleracea l.) i. in situ localization by indirect immunofluorescence.	antisera were raised against two forms of α-1,4-glucan phosphorylase (ec 2.4.1.1) which had been purified from leaves of spinacia oleracea l. immunoglobulin g preparations were isolated from the antisera, and their specificity was ensured by immunoplobulin g preparations were used for in situ localization of the two phosphorylase forms in spinach leaf thin sections by indirect immuno-fluorescence. both enzyme forms were present in the palisade and spongy parenchyma and in the guard cells, but th ...	1986	24240359
the influence of a decrease in irradiance on photosynthetic carbon assimilation in leaves of spinacia oleracea l.	when leaves of spinacia oleracea l. were subjected to a decrease from a saturating to a limiting irradiance, photosynthetic carbon assimilation exhibited a pronounced lag. this comprised a postlower-illumination co2 burst (vines et al. 1982, plant physiol. 70, 629-631) and a slow increase in the rate of carbon assimilation to the new lower steady-state rate. the latter phenomenon was distinguishable from the former because it was present in leaves when photorespiration was inhibited by high conc ...	1986	24240313
the relationship between phosphate status and photosynthesis in leaves : reversibility of the effects of phosphate deficiency on photosynthesis.	spinach (spinacia oleracea l.) and barley (hordeum vulgare l.) were grown in hydroponic culture with varying levels of orthophosphate (pi). when leaves were fed with 20 mmol·l(-1) pi at low co2 concentrations, a temporary increase of co2 uptake was observed in pi-deficient leaves but not in those from plants grown at 1 mmol·l(-1) pi. at high concentrations of co2 (at 21% or 2% o2) the pi-induced stimulation of co2 uptake was pronounced in the pi-deficient leaves. the contents of phosphorylated m ...	1986	24240307
the relationship between phosphate status and photosynthesis in leaves : effects on intracellular orthophosphate distribution, photosynthesis and assimilate partitioning.	photosynthesis, assimilate partitioning and intracellular distribution of orthophosphate (pi) in barly (hordeum vulgare l.) leaves were measured in plants grown with either 25, 1 or 0 mmol· 1(-1) nutrient phosphate supply. phosphate deficiency resulted in a significant decrease in the leaf pi, diminished rates of photosynthesis and a decrease in the sucrose/starch ratio in the leaves. changes in the cytoplasmic pi content were relatively small in comparison with the large variations in vacuolar ...	1986	24240306
stimulation of photosynthesis by 2% oxygen at low temperatures is restored by phosphate.	the effect of phosphate feeding on the influence of low (2%) oxygen on photosynthetic carbon assimilation has been investigated in leaf discs of spinach (spinacia oleracea l.) at 12°c. the following observations were made. first, after the transition from 20% o2 to 2% o2, the rate of co2 uptake was inhibited at co2 concentrations between about 250 and about 800 μl co2·l(-1). second, phosphate feeding stimulated the rate of co2 uptake in 20% o2 at higher concentrations of co2 (500-900 μl·l(-1)). ...	1986	24233739
simulation of in situ freezing damage of the photosynthetic apparatus by freezing in vitro of thylakoids suspended in complex media.	chloroplast thylakoid membranes were isolated from leaves of unhardened and cold-acclimated spinach (spinacia oleracea l.). for freezethaw treatment, the membranes were suspended in complex media composed to simulate the solute concentrations in the chloroplast stroma in the unhardened and hardened states of the leaves. in particular, high concentrations of amino acids were applied for simulating the hardened state. after frost treatment, photosynthetic activities and chlorophyll fluorescence pa ...	1986	24233737
salt treatment induces frost hardiness in leaves and isolated thylakoids from spinach.	frost hardiness of spinach (spinacia oleracea l.) leaves was increased by high concentrations of nacl in the hydroponic culture medium. freezing damage was determined by measurement of slow chlorophyll fluorescence quenching after freezing of leaves. both the osmolality of the leaf sap and forst hardiness of the leaves were linearly correlated with the salt concentration in the hydroponic culture medium. freezing damage occurred, irrespective of the extent of frost hardening, when dehydration of ...	1986	24233734
resolution of two molecular forms of sucrose-phosphate synthase from maize, soybean and spinach leaves.	two forms of sucrose-phosphate synthase (ec 2.4.1.14) were resolved from leaves of three species, maize (zea mays l. cv. pioneer 3184), soybean (glycine max (l.) merr., cv. ransom) and spinach (spinacia oleracea l. cv. resistoflay) by hydroxyapatite ultrogel chromatography, using a 75-mm (designated peak 1) and 250-mm (peak 2) k-phosphate discontinuous-gradient elution. rechromatography of the two forms showed that they were not readily interconvertible. the distribution of activity between the ...	1987	24233014
characterization and properties of the spinach chloroplast transcriptionally active chromosome isolated at high ionic strength.	the transcriptionally active chromosome (tac) of spinach (spinacia oleracea l.) chloroplasts has been isolated at a high ionic strength, with low mechanical shearing, by glycerol gradient centrifugation. the properties of the tac differ from those previously reported for the tac isolated either from euglena chloroplasts or from spinach using a low-ionic-strength solubilization medium and gel filtration. the high-salt-isolated tac is homogenous in density but not in size and contains fewer weakly ...	1986	24232757
freezing of isolated thylakoid membranes in complex media : iii. differences in the pattern of inactivation of photosynthetic reactions.	chloroplast thylakoid membranes isolated from spinach leaves (spinacia oleracea l. cv. monatol) were subjected to a freeze-thaw treatment in a buffered medium containing 70 mm kcl, 30 mm nano3 and 20 mm k2so4 in different combinations. in the presence of the three predominant inorganic electrolytes, inactivation of photophosphorylation was mainly caused by a decrease in the capacity of the photosynthetic electron transport; release of proteins from the membranes was not manifest and light-induce ...	1986	24232033
α-1,4-glucan phosphorylase forms from leaves of spinach (spinacia oleracea l.) : ii. peptide patterns and immunological properties. a comparison with other phosphorylase forms.	peptide patterns and immunological properties of the cytoplasmic and chloroplastic α-1,4-glucan phosphorylase (ec 2.4.1.1) from spinach leaves have been studied and were compared with those of phosphorylases from other sources. the two spinach leaf phosphorylases were immunologically different; a limited cross-reactivity was observed only at high antigen or antibody concentrations. peptide mapping of the two enzymes resulted in complex patterns composed of more than 20 fragments; but no peptide ...	1986	24232025
calcium binding by spinach stromal proteins.	calcium binding to spinach (spinacia oleracea l.) stromal proteins was examined by dual-wavelength spectrophotometry using the metallochromic indicator tetramethylmurexide. the data are consistent with the existence of at least two, probably independent, classes of binding sites. the total number of binding sites varied between 90-155 nmol·mg(-1) protein with "average" binding constants of 1.1-2.7·mm(-1). both mg(2+) and la(3+) inhibited calcium binding competitively, with "average" inhibitor co ...	1987	24227335
non-photochemical quenching of chlorophyll a fluorescence in isolated chloroplasts under conditions of stressed photosynthesis.	non-photochemical quenching of chlorophyll a fluorescence after short-time light, heat and osmotic stress was investigated with intact chloroplasts from spinacia oleracea l. the proportions of non-photochemical fluorescence quenching (q n ) which are related (q e ) and unrelated (q i ) to the transthylakoid proton gradient (δph) were determined. light stress resulted in an increasing contribution of q ito total q n.the linear dependence of q. eand δph, as seen in controls, was maintained. the me ...	1987	24227329
chalcone synthases from spinach (spinacia oleracea l.) : ii. immunofluorescence and immunogold localization.	the distribution of the two chalcone synthases in leaves ofspinacia oleracea l. was studied at both the tissue and the subcellular level using immunofluorescence and immunogold techniques. neither technique differentiated between the two enzyme forms. the chalcone synthases are located in the upper and the lower epidermis and to a minor extent in the subepidermal layers. traces of the two enzyme forms may be present in the residual mesophyll. this distribution is independent of leaf age. a simil ...	1988	24226692
chalcone synthases from spinach (spinacia oleracea l.) : i. purification, peptide patterns, and immunological properties of different forms.	the two chalcone-synthase forms from leaves ofspinacia oleracea l. were purified to apparent homogeneity. antibodies were raised against both proteins in rabbits. the specificity of the antibodies was tested using immunotitration, immunoblotting, and immunoelectrophoresis techniques. the antibodies exhibited exclusive specificity for chalcone synthase and did not discriminate between the two antigens. the homodimeric chalcone synthases had the same subunit molecular weight but differed in their ...	1988	24226691
effect of high light intensities on oxygen evolution and the light activation of nadp-malate dehydrogenase in intact spinach chloroplasts.	the factors limiting the photosynthetic carbon metabolism of intact spinach (spinacia oleracea l.) chloroplasts after a high-light pretreatment have been studied. photosynthetic co2 fixation was decreased and became more sensitive to the inhibitory effect of the cyclic-electron-flow inhibitor, antimycin a. depending on the extent of photoinhibition, changing the balance of linear to cyclic electron flow by adding oxaloacetate and antimycin a either did not relieve, or partially relieved the phot ...	1988	24226683
fractional control of photosynthesis by the qb protein, the cytochrome f/b 6 complex and other components of the photosynthesic apparatus.	in order to obtain information on fractional control of photosynthesis by individual catalysts, catalytic activities in photosynthetic electron transport and carbon metabolism were modified by the addition of inhibitors, and the effect on photosynthetic flux was measured using chloroplasts of spinacia oleracea l. in thylakoids with coupled electron transport, light-limited electron flow to ferricyanide was largely controlled by the qb protein of the electron-transport chain. fractional control b ...	1988	24226408
coarse control of sucrose-phosphate synthase in leaves: alterations of the kinetic properties in response to the rate of photosynthesis and the accumulation of sucrose.	it has been investigated whether diurnal rhythms of sucrose-phosphate synthase (sps) are involved in controlling the rate of photosynthetic sucrose synthesis. extracts were prepared from spinach (spinacia oleracea l.) and barley (hordeum vulgare l.) leaves and assayed for enzyme activity. the activity of sps increased in parallel with a rising rate of photosynthesis, and was increased by feeding mannose and decreased by supplying inorganic phosphate. in leaf material where sucrose had accumulate ...	1988	24221478
chloroplast dna evolution in potato (solanum tuberosum l.).	a deletion specific to chloroplast (ct) dna of potato (solanum tuberosum ssp. tuberosum) was determined by comparative sequence analysis. the deletion was 241 bp in size, and was not flanked by direct repeats. five small, open reading frames were found in the corresponding regions of ctdnas from wild potato (s. tuberosum ssp. andigena) and tomato (lycopersicon esculentum). comparison of the sequences of 1.35-kbp haeiii ctdna fragments from potato, tomato, and tobacco (nicotiana tabacum) revealed ...	1991	24221153
role of plastidial acyl-acyl carrier protein: glycerol 3-phosphate acyltransferase and acyl-acyl carrier protein hydrolase in channelling the acyl flux through the prokaryotic and eukaryotic pathway.	in order to investigate whether the relative activities of the plastidial acyl-acyl carrier protein (acp):glycerol 3-phosphate acyltransferase (ec 2.3.1.15) and acyl-acp hydrolase play a role in controlling the acyl flux through the prokaryotic and eukaryotic pathway, we determined these enzymic activities in stroma fractions from 16:3- and 18:3-plants using glycerol 3-phosphate and labelled acyl-acp as substrates. several factors were examined which might influence the activities within plastid ...	1988	24220947
import of peroxisomal hydroxypyruvate reductase into glyoxysomes.	a new procedure was used to purify the peroxisomal matrix enzyme hydroxypyruvate reductase (hpr) from green leaves of pumpkin (cucurbita pepo l.) and spinach (spinacia oleracea l.). monospecific antibodies were prepared against this enzyme in rabbits. immunoprecipitation of hpr from watermelon (citrullus vulgaris schrad.) yielded a single protein with a subunit molecular weight of 45 kda. immunohistochemical labeling of hpr was found exclusively in watermelon microbodies. isolated polyadenylated ...	1988	24220768
phosphate sequestration by glycerol and its effects on photosynthetic carbon assimilation by leaves.	glycerol induced a limitation on photosynthetic carbon assimilation by phosphate when supplied to leaves of barley (hordeum vulgare l.) and spinach (spinacia oleracea l.). this limitation by phosphate was evidenced by (i) reversibility of the inhibition of photosynthesis by glycerol by feeding orthophosphate (ii) a decrease in light-saturated rates of photosynthesis and saturation at a lower irradiance, (iii) the promotion of oscillations in photosynthetic co2 assimilation and in chlorophyll flu ...	1988	24220742
shoot regeneration from spinach hypocotyl segments by short term treatment with 5,6-dichloro-indole-3-acetic acid.	factors affecting shoot regeneration from hypocotyl segments of spinach (spinacia oleracea l.) were investigated. when expiants were cultured on medium containing 10 mg/l iaa for 7 weeks, 3 out of 9 cultivars showed relatively high shoot regeneration response (15 - 35%). the other pgrs tested had no effect on shoot regeneration. however, the transfer of explants from auxin-containing medium to auxin-free medium 20 d after culture induced shoot formation from expiants cultured on media containing ...	1992	24213485
comparative biochemical and immunological studies of the glycine betaine synthesis pathway in diverse families of dicotyledons.	members of the chenopodiaceae can accumulate high levels (>100 μmol·(g dw)(-1)) of glycine betaine (betaine) in leaves when salinized. chenopodiaceae synthesize betaine by a two-step oxidation of choline (choline→betaine aldehyde→ betaine), with the second step catalyzed by betaine aldehyde dehydrogenase (badh, ec 1.2.1.8). high betaine levels have also been reported in leaves of species from several distantly-related families of dicotyledons, raising the question of whether the same betaine-syn ...	1989	24212901
short-term water stress leads to a stimulation of sucrose synthesis by activating sucrose-phosphate synthase.	the aim of this work was to identify which aspects of photosynthetic metabolism respond most sensitively to leaf water deficit. spinach (spinacia oleracea l.) leaf discs were floated on sorbitol concentrations of increasing molarity and changes of the protoplast volume were estimated using [(14)c]sorbitol and (3)h2o penetration. detached leaves were also wilted until 10% of their fresh weight was lost. photosynthesis was studied at very high external co2 concentrations, to eliminate the effect o ...	1989	24212496
comparison of acetate- and pyruvate-dependent fatty-acid synthesis by spinach chloroplasts.	in recent studies using intact chloroplasts of spinach (spinacia oleracea l.) to investigate the accumulation of acetyl-coa produced by the activity of either acetyl-coa synthetase (ec 6.2.1.1) or the pyruvate-dehydrogenase complex, this product was not detectable. these results in combination with new information on the physiological levels of acetate and pyruvate in spinach chloroplasts (h.-j. treede et al. 1986, z. naturforsch. 41 c, 733-740) prompted a reinvestigation of the incorporation of ...	1989	24212436
photoinhibition at chilling temperature : fluorescence characteristics of unhardened and cold-acclimated spinach leaves.	the effects of moderate light at chilling temperature on the photosynthesis of unhardened (acclimated to +18° c) and hardened (cold-acclimated) spinach (spinacea oleracea l.) leaves were studied by means of fluorescence-induction measurements at 20° c and 77k and by determination of quantum yield of o2 evolution. exposure to 550 μmol photons·m(-2)·s(-1) at +4° c induced a strong photoinhibition in the unhardened leaves within a few hours. photoinhibition manifested by a decline in quantum yield ...	1989	24212435
response of photosynthesis and respiration of resurrection plants to desiccation and rehydration.	using non-invasive techniques (co2 gas exchange, light scattering, light absorption, chlorophyll fluorescence, chlorophyll luminescence), we have analysed the response of respiration and photosynthesis to dehydration and rehydration of leaves of the resurrection plants craterostigma plantagineum hochst., ramonda mykoni reichb. and ceterach officinarum lam. et dc. and of the drought-sensitive mesophyte spinach (spinacia oleracea l.). the following observations were made: (i) the rate of water los ...	1989	24212344
regulation of sucrose-phosphate-synthase activity in spinach leaves by protein level and covalent modification.	a dot-blot technique was developed using monoclonal antibodies to measure, rapidly and accurately, the amount of sucrose-phosphate synthase (sps; ec 2.4.1.14) protein present in a crude extract from spinach (spinacia oleracea l. cv. dark green bloomsdale) leaves; this was compared with sps activity in this material. during leaf development, increased sps activity followed closely the increase in enzyme-protein level, indicating denovo synthesis or altered turn-over rates for sps. in contrast, ac ...	1989	24212279
proteins from frost-hardy leaves protect thylakoids against mechanical freeze-thaw damage in vitro.	we have isolated protein fractions from cold-acclimated, frost-hardy cabbage (brassica oleracea l.) and spinach (spinacia oleracea l.) leaves which protect isolated thylakoids from non-hardy spinach against mechanical membrane rupture during an in-vitro freeze-thaw cycle. no protective activity was found in similar preparations from non-hardy leaves. the proteins protected the membranes from damage by reducing their solute permeability during freezing and by increasing their expandability during ...	1990	24202022
protective systems against active oxygen species in spinach: response to cold acclimation in excess light.	spinach (spinacia oleracea l.) plants were acclimated to 1° c or maintained at 18° c under the same light regime (260-300 μmol photons·m(-2)·s(-1)). the cold acclimation led to several metabolic and biochemical changes that apparently include improved protection of the photosynthetic apparatus against active oxygen species. in particular, cold-acclimated leaves exhibited a considerably higher ascorbate content and significantly increased activities of superoxide dismutase, ascorbate peroxidase, ...	1990	24202017
the ferredoxin-thioredoxin system of a green alga, chlamydomonas reinhardtii : identification and characterization of thioredoxins and ferredoxin-thioredoxin reductase components.	the components of the ferredoxin-thioredoxin (ft) system of chlamydomonas reinhardtii have been purified and characterized. the system resembled that of higher plants in consisting of a ferredoxin-thioredoxin reductase (ftr) and two types of thioredoxin, a single f and two m species, m1 and m2. the chlamydomonas m and f thioredoxins were antigenically similar to their higher-plant counterparts, but not to one another. the m thioredoxins were recognized by antibodies to both higher-plant m and ba ...	1990	24202012
reversible photoinhibition of unhardened and cold-acclimated spinach leaves at chilling temperatures.	the photoinhibition of photosynthesis at chilling temperatures was investigated in cold-acclimated and unhardened (acclimated to +18° c) spinach (spinacia oleracea l.) leaves. in unhardened leaves, reversible photoinhibition caused by exposure to moderate light at +4° c was based on reduced activity of photosystem (ps) ii. this is shown by determination of quantum yield and capacity of electron transport in thylakoids isolated subsequent to photoinhibition and recovery treatments. the activity o ...	1990	24201942
localization of a protein, immunologically similar to a sucrose-binding protein from developing soybean cotyledons, on the plasma membrane of sieve-tube members of spinach leaves.	immunocytochemical studies using antibodies raised against a 62-kda membrane protein isolated from developing soybean (glycine max (l.) merr.) cotyledons were performed on leaf tissue of spinach (spinacia oleracea l.). this 62-kda protein was labeled by 6'-deoxy-6'-(4-azido-2-hydroxy)-benzamidosucrose (habs), a photoaffinity sucrose analogue (k. g. ripp et al., 1988, plant physiol.88, 1435-1445). western-blot analysis of spinach plasma-membrane proteins indicated a cross-reactive polypeptide ide ...	1989	24201850
fluorescence microscopy and radiolabeling of c3 and c 4 chloroplasts using diisothiocyanatostilbene disulfonic acid as a marker for the phosphate translocator.	the usefulness of 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (dids) for in-situ studies of the chloroplast phosphate translocator was evaluated by fluorescence microscopy and radiolabeling of spinach (spinacia oleracea l.) (c3 plant) and maize (zea mays l.) (c4 plant) chloroplasts. in maize mesophyll and bundle-sheath chloroplasts and in spinach chloroplasts that were either intact, broken or swollen, dids fluorescence was only associated with the chloroplast envelope. intact chloroplast ...	1989	24201512
regulation of photosynthetic sucrose synthesis: a role for calcium?	we have investigated whether changes of the cytosolic free-calcium concentration could regulate photosynthetic sucrose synthesis. partially purified enzymes from spinach (spinacea oleracea l.) leaves were assayed using calcium-egta buffers to obtain defined free-calcium concentrations in the low micromolar and submicromolar ranges. these concentrations of calcium did not directly affect sucrose-phosphate synthase activity. they inhibited the cytosolic fructose-1,6-bisphosphatase, acting competit ...	1990	24197102
control of photosynthate partitioning in spinach leaves : analysis of the interaction between feedforward and feedback regulation of sucrose synthesis.	experiments were carried out to estimate the elasticity coefficients and thence the distribution of control of sucrose synthesis and photosynthate partitioning between cytosolic fructose-1,6-bisphosphatase and sucrose-phosphate synthase (sps), by applying the dualmodulation method of kacser and burns (1979, biochem. soc. trans. 7, 1149-1161). leaf discs of spinach (spinacia oleracea l.) were harvested at the beginning and end of the photoperiod and illuminated at five different irradiances to al ...	1990	24196941
the aggregation states of spinach phosphoribulokinase.	phosphoribulokinase (prk; ec 2.1.7.19) is active in illuminated chloroplasts and inactive in darkened chloroplasts. this regulatory mechanism is mediated by thioredoxin-dependent reduction of a kinase disulfide in vivo. extracts of spinach (spinacia oleracea l.) leaves in the presence of 10 mm dithiothreitol contain a single 80-kda form of prk as judged by gel filtration. gel filtration of thiol-free extracts of light-harvested tissue shows the presence of two inactive forms of prk, the 80-kda f ...	1990	24196813
characterization and compartmentation, in green leaves, of hexokinases with different specificities for glucose, fructose, and mannose and for nucleoside triphosphates.	when green leaves of spinach (spinacia oleracea l.) were surveyed for the presence of hexokinases which utilize glucose, fructose and-or mannose as a substrate, four kinases could be distinguished by their order of elution during chromatography on diethylaminoethyl (deae)-cellulose: (i) a hexokinase i with a specificity for fructose, glucose, and mannose, (ii) a fructokinase i with a specificity for fructose, (iii) a hexokinase ii with a specificity for glucose, fructose and mannose, and (iv) a ...	1990	24196745
regulation of sedoheptulose-1,7-bisphosphatase by sedoheptulose-7-phosphate and glycerate, and of fructose-1,6-bisphosphatase by glycerate in spinach chloroplasts.	using partially purified sedoheptulose-1,7-bisphosphatase from spinach (spinacia oleracea l.) chloroplasts the effects of metabolites on the dithiothreitoland mg(2+)-activated enzyme were investigated. a screening of most of the intermediates of the calvin cycle and the photorespiratory pathway showed that physiological concentrations of sedoheptulose-7-phosphate and glycerate specifically inhibited the enzyme by decreasing its maximal velocity. an inhibition by ribulose-1,5-bisphosphate was als ...	1990	24196680
embryogenesis and plant regeneration of spinach (spinacia oleracea l.) from hypocotyl segments.	a system for somatic embryogenesis and plant regeneration of spinach from hypocotyl segments has been established. callus was induced on solid media supplemented with 8.5-15.0 mg.l(-1) of indole-3-acetic acid and 3.46-34.64 mg.l(-1) gibberellic acid. callus was then subcultured on different media (solid or liquid) with or without iaa, or continuously maintained on the initiating media. somatic embryos were obtained in subcultures on iaa-containing media as well as in long-term cultures on initia ...	1993	24196289
purification of udp-galactose: diacylglycerol galactosyltransferase from chloroplast envelopes of spinach (spinacia oleracea l.).	uridine 5'-diphosphate(udp)-galactose: 1,2-diacylglycerol 3-o-β-d-galactopyranosyltransferase (ec 2.4.1.46) is an integral protein of chloroplast envelope membranes from which it has been partially purified (covès et al., 1986, febs lett. 208, 401-406). we have worked out a purification procedure which after removal of peripheral membrane proteins, solubilization and two chromotographic steps allowed us to identify a 22-kda protein as the galactosyltransferase. enrichment of enzymatic activity w ...	1991	24194148
photosynthetic oxygen evolution and chlorophyll fluorescence in intact isolated chloroplasts on a solid support: the influence of orthophosphate.	we devised recently a method to trap intact isolated chloroplasts on a solid support consisting of membrane filters made of cellulose nitrate (cerović et al., 1987, plant physiol. 84, 1249-1251). the addition of alkaline phosphatase to the reaction medium enabled continuous photosynthesis by spinach (spinacia oleracea l.) chloroplasts to be sustained by hydrolysis of newly produced and exported triose phosphates and recycling of orthophosphate. in this system, simultaneous measurements of chloro ...	1991	24194077
coaction of light, nitrate and a plastidic factor in controlling nitrite-reductase gene expression in spinach.	it is well established that nitrite reductase (nir; ec 1.7.7.1) a key enzyme of nitrate reduction - is "induced" by nitrate and light. in the present study with the spinach (spinacia oleracea l.) seedling the dependency of nir appearance on nitrate, light and a 'plastidic factor' was investigated to establish the nature of the coaction between these controlling factors. a cdna clone coding for spinach nir was available as a probe. the major results we have obtained are the following: (i) the lig ...	1991	24193932
the relationship between the activation state of sucrose-phosphate synthase and the rate of co2 assimilation in spinach leaves.	the relationship between the gas-exchange characteristics of spinach (spinacia oleracea l.) leaves and the activation state of sucrose-phosphate synthase was examined at different intercellular partial pressures of co2 at two different photon flux densities. there was a strong positive correlation between the activation state of sucrose-phosphate synthase and the assimilation rate. the relationship was the same at both photon flux densities, indicating that the activation state of the enzyme is ...	1991	24193857
inhibition of the transthylakoid gradient of electrochemical proton potential by the local anesthetic dibucaine.	the effects of the local anesthetic dibucaine on coupling between electron transport and atp synthesis-hydrolysis by the coupling-factor complex (cf0cf1 atpase) were investigated in thylakoid membranes from spinacia oleracea l. cv. monatol. evidence is presented that inhibition of atp synthesis was produced by a specific uncoupling mechanism which was based on dibucaine-membrane surface interactions rather than on the interaction of dibucaine with the atpase complex. dibucaine reduced the osmoti ...	1991	24193850
molecular cloning and structural analysis of the phosphate translocator from pea chloroplasts and its comparison to the spinach phosphate translocator.	using an 5'-avaii fragment of the spinach (spinacia oleracea l.) phosphate translocator cdna as a probe for a hybridization screening of a pea (pisum sativum l.) cdna library we have cloned and sequenced a cdna clone coding for the phosphate translocator precursor protein from pea chloroplasts. the full-length cdna clone comprises 42 base pairs (bp) at the 5'-non-coding region, a 1206-bp coding region corresponding to a polypeptide of 402 amino-acid residues (relative molecular mass 43 671) and ...	1991	24193755
the action of phosphatidate phosphatase on the fatty-acid composition of safflower triacylglycerol and spinach glycerolipids.	the microsomal phosphatidate phosphatase (ec 3.1.3.4) in maturing seeds of safflower (carthamus tinctorius l.) was specific and selective for unsaturated phosphatidates. the relative order of specificity for phosphatidate molecular species was 1,2-dilinoleoyl = 1,2-dioleoyl > 1-palmitoyl-2-oleoyl > 1,2-dilauroyl = 1,2-dimyristoyl > 1,2-dipalmitoyl. the order of selectivity was similar to that of the specificity. the broad selectivity for unsaturated phosphatidate species (1,2-di-unsaturated-acyl ...	1991	24193745
superoxide production by thylakoids during chilling and its implication in the susceptibility of plants to chilling-induced photoinhibition.	factors influencing the rate of superoxide (o 2 (-) ) production by thylakoids were investigated to determine if increased production of the radical was related to injury induced by chilling at a moderate photon flux density (pfd). plants used were spinacia oleracea l., cucumis sativus l. and nerium oleander l. grown at either 200° c or 45° c. superoxide production was determined by electron-spin-resonance spectroscopy of the (o 2 (-) )-dependent rate of oxidation of 2-ethyl-1-hydroxy-2,5,5-trim ...	1991	24193624
adenine nucleotides are apparently involved in the light-dark modulation of spinach-leaf nitrate reductase.	nitrate reductase (nr; ec 1.6.6.1) in spinach (spinacia oleracea l. cv. polka f1) leaves showed reversible modulation, being activated in the light and inactivated in the dark (t/2 = 20-30 min). the large changes in enzyme activity during light-dark transients were observed only when assayed in buffers containing free mg(2+). in the presence of edta (5 mm), the enzyme activity was high and the light modulation was barely evident.the inactivation of nr in the dark could be totally prevented by an ...	1992	24186663
identification of an nadp/thioredoxin system in chlamydomonas reinhardtii.	the protein components of the nadp/thioredoxin system, nadp-thioredoxin reductase (ntr) and thioredoxin h, have been purified and characterized from the green alga, chlamydomonas reinhardtii. the analysis of this system confirms that photoautotrophic chlamydomonas cells resemble leaves in having both an nadp- and ferrodoxin-linked thioredoxin redox system. chlamydomonas thioredoxin h, which is smaller on sodium dodecyl sulfate-polyacrylamide gel electrophoresis than thioredoxin m from the same s ...	1991	24186583
ribulose-1,5-bisphosphate carboxylase-oxygenase, other calvin-cycle enzymes, and chlorophyll decrease when glucose is supplied to mature spinach leaves via the transpiration stream.	the inhibition of photosynthesis after supplying glucose to detached leaves of spinach (spinacia oleracea l.) was used as a model system to search for mechanisms which potentially contribute to the "sink" regulation of photosynthesis. detached leaves were supplied with 50 mm glucose or water for 7 d through the transpiration stream, holding the leaves in low irradiance (16 μmol photons · m(-2) · s(-1)) and a cycle of 9 h light/15 h darkness to prevent any endogenous accumulation of carbohydrate. ...	1991	24186575
aspartic-acid synthesis in c3 plants.	in a previous study (melzer and o'leary, 1987, plant physiol. 84, 58-60), we used isotopic methods to show that a substantial fraction of protein-bound aspartic acid in tobacco is derived from anaplerotic synthesis via phosphoenolpyruvate (pep) carboxylase. similar studies in soybean (glycine max l.) and spinach (spinacia oleracea l.) showed a similar pattern, and this pattern persists with age because of slow protein turnover. a more quantitative analysis indicates that about 40% of protein-bou ...	1991	24186420
multiplicity of soluble glucan-synthase activity in spinach leaves: enzyme pattern and intracellular location.	buffer-extractable proteins from leaves of spinacia oleracea l. were separated by non-denaturing polyacrylamide gel electrophoresis. gels were stained for adenosine diphosphoglucose (adpglucose)-dependent glucan-synthase (gs) activity (ec 2.4.1.21). three major forms of activity were observed. no staining was detectable when adpglucose was replaced by an equimolar concentration of either uridine, guanosine or cytosine diphosphoglucose. two of the three gs forms exhibited both primed and citrate- ...	1991	24186345
lipid peroxidation and superoxide dismutase activity in relation to photoinhibition induced by chilling in moderate light.	the effect of a chilling stress, at a moderate photon flux density for a few hours, on the peroxidation of membrane lipids and on superoxide dismutase (sod) activity was compared in leaf slices of chilling-sensitive and chilling-insensitive plants. the aim was to determine if susceptibility to chill-temperature photoinhibition could be related to either damage to membrane lipids by superoxide and-or a decrease in activity of chloroplast sod. plants used were nerium oleander l., grown at 45° c, a ...	1991	24186344
binding sites of e. coli dna-dependent rna polymerase on spinach chloroplast dna.	under stringent conditions e. coli dna-dependent rna polymerase holoenzyme binds selectively to some spinach chloroplast dna fragments generated by restriction endonucleases. the strongest of these binding sites, as judged by the initial rate of complex formation, are located in the large single-copy dna region (crouse et al. 1978) of this molecule and correspond in map location with known protein coding sequences. some of these binding sites have characteristics of complex formation comparable ...	1981	24185866
efficient chimeric plant promoters derived from plant infecting viral promoter sequences.	in the present study, we developed a set of three chimeric/hybrid promoters namely fsgt-pflt, pflt-uas-2x and msgt-pflt incorporating different important domains of figwort mosaic virus sub-genomic transcript promoter (fsgt, -270 to -60), mirabilis mosaic virus sub-genomic transcript promoter (msgt, -306 to -125) and peanut chlorotic streak caulimovirus full-length transcript promoter (pflt-, -353 to +24 and pflt-uas, -353 to -49). we demonstrated that these chimeric/hybrid promoters can drive t ...	2014	24178585
response of a nitrite-reductase 3.1-kilobase upstream regulatory sequence from spinach to nitrate and light in transgenic tobacco.	in the present study the question was addressed of whether the nitrite-reductase (nir-)promoter from spinach (spinacia oleracea l.), fused to a reporter gene (bacterial β-glucuronidase, gus) and introduced into tobacco (nicotiana tabacum l.) responds to nitrate and light in accordance with spinach (donor) or in accordance with tobacco (host). the data obtained at the gus enzyme level as well as at the transcript level allow an unambiguous answer to this question: gus gene expression under the co ...	1993	24178503