Publications

[hill reaction and photophosphorylation of isolated chloroplasts in relation to water content : i. removal of water by means of concentrated solutions].	1. water was removed by means of concentrated solutions from chloroplasts which were isolated from leaves of spinach and beets. during and after the dehydration hill reaction and cyclic photophosphorylation with pms as a cofactor were investigated. as osmotic amterial glucose, sucrose, lutrol and nacl were used. 2. no depression of ferricyanide reduction was obtained in 3 m sugar solution and in 2.5 m lutrol solution. these concentrations correspond to a loss of water amounting to 90% of the tot ...	1967	24554371
some physiological responses to d,l abscisin (dormin).	the responses to synthetic d,l abscisin have been studied in a variety of tests. when fed in aqueous solution continuously to leaves of seedlings growing under long day conditions, d,l abscisin caused the cessation of extension growth and the formation of typical resting-buds in betula pubescens, acer pseudoplatanus and ribes nigrum. abscisin also inhibited the growth of non-dormant buds of potato when applied to the whole tubers, but was much less effective when applied to isolated tuber plugs. ...	1967	24554370
[studies on the backward-reactions in the xanthophyll-cycle of chlorella, spinacia and taxus].	the epoxidation of zeaxanthin to the di-epoxide violaxanthin via the mono-epoxide antheraxanthin (called the backward-reaction), is examined with several plant objects and under various conditions.in chlorella and in the needles of taxus baccata a backward-conversion can be observed immediately after the termination of strong illumination. the reaction can be accelerated somewhat by exposure of the plant material to pure o2 or dim light.one cannot observe such an epoxidation in leaf disks of spi ...	1967	24549422
detection of five shiga toxin-producing escherichia coli genes with multiplex pcr.	escherichia coli serogroup o157 is the pathogen most commonly associated with foodborne disease outbreaks, but epidemiological studies suggest that non-o157 shiga toxin-producing e. coli (stec) is a major player as well. the ten most clinically relevant stecs belong to serogroups o26, o103, o111, o145, o157, o91, o113, o128, o45, and o121; but emerging strains, such as o104:h4 that was identified with the 2011 german outbreak, could become more prevalent in the future. a 75-min conventional mult ...	2014	24549195
[the role of phosphorylase in starch metabolism in plastids].	two phosphorylases could be detected on gel-electropherograms of leaf-extracts of spinacia oleracea and of immature cotyledons of vicia faba. these two phosphorylases could be separated by means of ammonium sulfate fractionation. both the slower migrating phosphorylases from spinach and from beans, but not the fast one from beans, could be adsorbed on amyloplasts. this process takes place only when the amyloplasts are suspended in a salt medium. the slow phosphorylases can also be adsorbed on ch ...	1968	24522870
the effect of excess moisture on the germination of spinacia oleracea l.	the reversible inhibition of the germination of spinach (spinacia oleracea l.) seeds in conditions which are even slightly wetter than optimal has been traced to the production, in a wet environment, of a layer of mucilage around and within the fruit coat which surrounds the true seed. such wet seeds may however germinate readily when the temperature is lowered, or the oxygen pressure of the environment is raised, or the intact seeds are placed for a short time in hydrogen peroxide before being ...	1968	24519211
detection of cdt toxin genes in campylobacter spp. strains isolated from broiler carcasses and vegetables in são paulo, brazil.	campylobacteriosis is a worldwide distributed zoonosis. one of the main virulence factors related to campylobacter spp. in animals and humans is the cytolethal distending toxin (cdt), encoded by three adjacent genes (cdta, cdtb, cdtc). the occurrence of campylobacter spp. in samples of vegetables has not been reported in brazil yet, and has seldom been described in the international literature. the detection of cdt in these strains has not been reported, either. the objectives of the present stu ...	2014	24516435
enhanced photosynthetic activity in spinacia oleracea by spectral modification with a photoluminescent light converting material.	the spectral conversion of incident sunlight by appropriate photoluminescent materials has been a widely studied issue for improving the efficiency of photovoltaic solar energy harvesting. by using phosphors with suitable excitation/emission properties, also the light conditions for plants can be adjusted to match the absorption spectra of chlorophyll dyes, in this way increasing the photosynthetic activity of the plant. here, we report on the application of this principle to a high plant, spina ...	2013	24514932
trace level voltammetric determination of heavy metals and total mercury in tea matrices (camellia sinensis).	an analytical procedure regarding the voltammetric determination of mercury(ii), copper(ii), lead(ii), cadmium(ii) and zinc(ii) by square wave anodic stripping voltammetry (swasv) in matrices involved in food chain is proposed. in particular, tea leaves were analysed as real samples. the digestion of each matrix was carried out using a concentrated hcl-hno3-h2so4 acidic attack mixture; 0.01 mol l(-1) edta-na2 + 0.15 mol l(-1) nacl + 0.5 mol l(-1) hcl was employed as the supporting electrolyte. t ...	2013	24513061
evaluation of a loop-mediated isothermal amplification suite for the rapid, reliable, and robust detection of shiga toxin-producing escherichia coli in produce.	shiga toxin-producing escherichia coli (stec) strains are a leading cause of produce-associated outbreaks in the united states. rapid, reliable, and robust detection methods are needed to better ensure produce safety. we recently developed a loop-mediated isothermal amplification (lamp) suite for stec detection. in this study, the stec lamp suite was comprehensively evaluated against real-time quantitative pcr (qpcr) using a large panel of bacterial strains (n = 156) and various produce items (s ...	2014	24509927
farm management, environment, and weather factors jointly affect the probability of spinach contamination by generic escherichia coli at the preharvest stage.	the national resources information (nri) databases provide underutilized information on the local farm conditions that may predict microbial contamination of leafy greens at preharvest. our objective was to identify nri weather and landscape factors affecting spinach contamination with generic escherichia coli individually and jointly with farm management and environmental factors. for each of the 955 georeferenced spinach samples (including 63 positive samples) collected between 2010 and 2012 o ...	2014	24509926
genetic diversity of functional food species spinacia oleracea l. by protein markers.	exploration of genetic diversity contributes primarily towards crop improvement. spinaciaoleracea l. is a functional food species but unfortunately the genetic diversity of this vegetable is still unexplored. therefore, this research was planned to explore the genetic diversity of s. oleracea by using morphological and protein markers. protein profile of 25 accessions was generated on sodium dodecyl sulphate polyacrylamide gel. total allelic variation of 27 bands was found. out of these, 20 were ...	2014	24499432
effects of some phenoloxidase inhibitors on chloroplasts and carboxylating enzymes of sugar cane and spinach.	a number of additives have been tested for their effects on o-diphenol: o2 oxidoreductase activity of cane leaves. the most inhibitory compounds were thioglycollate, β-mercaptoethanol, polyethylene glycol and bovine serum albumin. sulphydryl (sh) compounds did not affect rates of photosynthetic co2 assimilation when used at concentrations below 10(-2) m. however, in the presence of mn(++) ions they contributed to an o2 consumption which masked photosynthetic o2 evolution. addition of sh compound ...	1970	24496906
[regulation of glucose-6-phosphate dehydrogenase in spinach chloroplasts by light].	1. the activity of the glucose-6-phosphate dehydrogenase (d-glucose-6-phosphate: nadph oxidoreductase, ec 1.1.1.49) in the homogenate of illuminated leaves of spinacea oleracea l. (30 min with 30000 lux) is about 30% lower than in the dark controls. 2. illumination of isolated chloroplasts (10000 lux) causes a fast inhibition of the enzyme activity which reaches about 45% after 20 min. 3. the activity of the 6-phosphogluconate dehydrogenase (6-phospho d-gluconate: nadp(+) oxidoreductase, ec 1.1. ...	1970	24496814
laser optical sensor, a label-free on-plate salmonella enterica colony detection tool.	we investigated the application capabilities of a laser optical sensor, bardot (bacterial rapid detection using optical scatter technology) to generate differentiating scatter patterns for the 20 most frequently reported serovars of salmonella enterica. initially, the study tested the classification ability of bardot by using six salmonella serovars grown on brain heart infusion, brilliant green, xylose lysine deoxycholate, and xylose lysine tergitol 4 (xlt4) agar plates. highly accurate discrim ...	2014	24496794
interpretations on chloroplast reproduction derived from correlations between cells and chloroplasts.	the size ranges of chloroplasts in living mesophyll cells of spinacia oleracea, allium cepa, beta vulgaris (swiss chard and red beet) and nicotiana glutinosa are extremely wide, e.g., ranging from about 6 µ(2) to 103 µ(2) in face area for spinach. moreover, the size distributions are positively skewed. we interpret the size range and skewed size distributions primarily to reflect an enormous growth of the bulk of the chloroplasts from small, equal-sized chloroplasts produced by fission of a smal ...	1971	24493165
[differences in the light-activation of nadp-dependent glyceraldehyde-3-phosphate dehydrogenase and of ribulose-5-phosphate kinase between plants containing the calvin and those containing the c4-dicarboxylic acid pathway of photosynthetic carbon reduction].	1. preceding experiments had shown that irradiance of intact leaves or of isolated chloroplasts causes a reversible increase in the activity of nadp-gpd (ziegler and ziegler, 1965) as well as of ribulose-5-phosphate kinase (latzko and gibbs, 1969). examination of several species which carry out the calvin type of photosynthetic co2 fixation (vicia faba, spinacia oleracea, nicotiana tabacum, avena sativa) now revealed that the dark level of nadp-gpd activity ranges between 300-400 μmol nadph/mg c ...	1971	24493083
thermal inactivation of human norovirus surrogates in spinach and measurement of its uncertainty.	leafy greens, including spinach, have potential for human norovirus transmission through improper handling and/or contact with contaminated water. inactivation of norovirus prior to consumption is essential to protect public health. because of the inability to propagate human noroviruses in vitro, murine norovirus (mnv-1) and feline calicivirus (fcv-f9) have been used as surrogates to model human norovirus behavior under laboratory conditions. the objectives of this study were to determine therm ...	2014	24490922
absence of internalization of escherichia coli o157:h7 into germinating tissue of field-grown leafy greens.	both growth chamber and field studies were conducted to investigate the potential for escherichia coli o157:h7 to be internalized into leafy green tissue when seeds were germinated in contaminated soil. internalized e. coli o157:h7 was detected by enrichment in both spinach (spinacia oleracea l.) and lettuce (lactuca sativa l.) seedlings when seeds were germinated within the growth chamber in autoclaved and nonautoclaved soil, respectively, contaminated with e. coli o157:h7 at 2.0 and 3.8 log cf ...	2014	24490912
[isolation and properties of mitochondria from leaves of spinacia oleracea and beta vulgaris].	from mature green leaves of spinacia oleracea and beta vulgaris a fraction has been obtained which is enriched in mitochondria. washed leaves were crushed in a meat-mill in an isotonic or slightly hypertonic medium containing sucrose, edta, mgso4, bovine serum albumin, mercaptoethanol, kh2po4, and hepes as a buffer substance. after squeezing through nylon the suspension was centrifuged first at 1500xg, and following removal of the sediment a second time at 25000xg. after resuspension in a washin ...	1971	24488246
the protective effect of sugars on chloroplast membranes during temperature and water stress and its relationship to frost, desiccation and heat resistance.	freezing, desiccation and high-temperature stress may under certain conditions result in inactivation of electron transport (dcip reduction) and cyclic photophosphorylation of isolated chloroplast membranes of spinach (spinacia oleracea l.). when sugars are present during temperature and water stress, the thylakoids may be partially or completely protected. this membrane stabilization depends on the concentration of sugars and their molecular size. the trisaccharide raffinose is, on a molar basi ...	1973	24468903
revisiting the classification of curtoviruses based on genome-wide pairwise identity.	members of the genus curtovirus (family geminiviridae) are important pathogens of many wild and cultivated plant species. until recently, relatively few full curtovirus genomes have been characterised. however, with the 19 full genome sequences now available in public databases, we revisit the proposed curtovirus species and strain classification criteria. using pairwise identities coupled with phylogenetic evidence, revised species and strain demarcation guidelines have been instituted. specifi ...	2014	24463952
heavy metal contamination of vegetables in isfahan, iran.	vegetables are an inevitable and important part of a healthy and balanced diet. they could be contaminated by heavy metals in many ways including irrigation by sewage water and industrial effluents sewage sludge, vehicular emissions, industrial waste and atmospheric deposition. in this study, we sought to determine if some vegetables (cucumbers, tomatoes, cabbage, lettuce, potatoes, onions, carrots, persian leeks, dill, spinach, coriander, parsley) grown locally in the suburban of isfahan city a ...	2013	24459476
[behavior of a mitochondrial population in the shoot apex of spinach].	in spinach (spinacia oleracea) certain mitochondria of the sporogenic promeristem would appear to show lysosomal involvement. this occasional involvement occurs when the photoperiodic conditions do not favor flowering. the mitochondrial morphological changes indicate increase in the production of membrane. the acid phosphatase activity normally found in the neighbourhood of the dictyosomes is present.	1974	24458994
temperature dependence of the permeability of chloroplasts from chilling-sensitive and chilling-resistant plants.	osmotic responses of chloroplasts from chilling-resistant (pisum sativum l., spinacia oleracea l.) and chilling-sensitive (phaseolus vulgaris l., lycopersicon esculentum mill.) plants to glycerol and erythritol were determined from 1° to 28°. the permeability of the chloroplast limiting membranes, as measured by reflection coefficients, decreased when the temperature was raised. for pisum and spinacia the curves relating reflection coefficients and temperature were smooth, while for phaseolus an ...	1974	24458931
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 ...	1984	24458606
molecular structure and subcellular localization of spinach leaf glycolate oxidase.	glycolate oxidase (e.c. 1.1.3.1) was purified from spinach leaves (spinacia oleracea). the molecular weight of the native protein was determined by sucrose density gradient centrifugation to be 290,000 daltons (13s), whereas that of the monomeric form was 37,000 daltons. the quaternary structure of the holoenzyme is likely to be octameric, analogous to pumpkin cotyledon glycolate oxidase [nishimura et al, 1982]. the subcellular localization of the enzyme was studied using linear sucrose density ...	1983	24458446
molecular structure and subcellular localization of spinach leaf glycolate oxidase.	glycolate oxidase (e.c. 1.1.3.1) was purified from spinach leaves (spinacia oleracea). the molecular weight of the native protein was determined by sucrose density gradient centrifugation to be 290,000 daltons (13s), whereas that of the monomeric form was 37,000 daltons. the quaternary structure of the holoenzyme is likely to be octameric, analogous to pumpkin cotyledon glycolate oxidase [nishimura et al, 1982]. the subcellular localization of the enzyme was studied using linear sucrose density ...	1983	24458389
the stability of electron transport in in vitro chloroplast membranes.	the stability and stabilization of the electron transport system of chloroplast membranes under physiological conditions of temperature and illumination were studied in relation to two separate and often competing mechanisms of decay. photochemical inactivation (photoinhibition) of the electron transport system of ageing spinach chloroplasts was not normally found to limit stability even at saturating light intensities. only when the membranes were protected from dark (fatty acid) inhibition did ...	1982	24458288
association between photosynthesis and contrasting features of minor veins in leaves of summer annuals loading phloem via symplastic versus apoplastic routes.	foliar vascular anatomy and photosynthesis were evaluated for a number of summer annual species that either load sugars into the phloem via a symplastic route (cucumis sativus l. cv. straight eight; cucurbita pepo l. cv. italian zucchini romanesco; citrullus lanatus l. cv. faerie hybrid; cucurbita pepo l. cv. autumn gold) or an apoplastic route (nicotiana tabacum l.; solanum lycopersicum l. cv. brandywine; gossypium hirsutum l.; helianthus annuus l. cv. soraya), as well as winter annual apoplast ...	2014	24450755
leaf anatomical and photosynthetic acclimation to cool temperature and high light in two winter versus two summer annuals.	acclimation of foliar features to cool temperature and high light was characterized in winter (spinacia oleracea l. cv. giant nobel; arabidopsis thaliana (l.) heynhold col-0 and ecotypes from sweden and italy) versus summer (helianthus annuus l. cv. soraya; cucurbita pepo l. cv. italian zucchini romanesco) annuals. significant relationships existed among leaf dry mass per area, photosynthesis, leaf thickness and palisade mesophyll thickness. while the acclimatory response of the summer annuals t ...	2014	24450735
[the influence of starch on the activity of pyrophosphatase from isolated spinach chloroplasts].	the activity of the inorganic pyrophosphatase from isolated spinach (spinacia oleracea l.) chloroplasts is strongly dependent upon the addition of magnesium ions. since the complex of the bivalent ion with inorganic pyrophosphate is the real substrate, a definite mg(2+)/na4p2o7-ratio is required for maximum activity. when the activity was measured in particle-free extracts from chloroplasts, this ratio was shown to be approximately 3. however, an increase up to 10 was observed in the presence of ...	1974	24442654
separation and characterization of two inorganic pyrophosphatases from spinach leaves.	two inorganic pyrophosphatases (pyrophosphate phosphohydrolase, e.c.3.6.1.1) have been identified in spinach (spinacia oleracea l.) leaves. the two isoenzymes were readily separated by polyacrylamide gel electrophoresis and by isoelectric focusing between ph 4 and 6. one isoenzyme is located in the chloroplasts whereas the other form was isolated from the soluble "cytoplasmic" fraction. in addition, a third form appeared when the isolation procedure started from a crude extract from whole leaves ...	1974	24442653
amino acid permeability of the chloroplast envelope as measured by light scattering, volumetry and amino acid uptake.	the amino acid permeability of the envelope of intact, functional spinach (spinacia oleracea l.) chloroplasts was investigated by light scattering, volumetry and uptake of (14)c-labelled amino acids. the criterion for the functionally of the chloroplasts was their ability to reduce co2, pga and oxaloacetate in the light at high rates.net uptake into the chloroplast interior of neutral amino acids such as alanine, glycine, serine, proline, threonine or valine occurred only at very low rates. the ...	1974	24442617
uptake and reduction of glycerate by isolated chloroplasts.	intact chloroplasts of spinach (spinacia oleracea l.) evolve o2 in the light in a glycerate-dependent reaction at rates usually close to 10 μmolxmg(-1) chlorophyllxh(-1). glycerate isfirst phosphorylated and the resulting phosphoglycerate reduced to the sugar level. products of the reaction are the intermediates of the calvin cycle and glycolate. the ratio of triosephosphates to phosphoglycerate is higher under low light or at a low ph than under high light or at a high ph. chloroplasts contain ...	1974	24442616
localization of the c4 and c 3 pathways of photosynthesis in the leaves of pennisetum purpureum and other c4 species. insignificance of phenol oxidase.	mesophyll protoplasts and bundle-sheath cells of pennisetum purpureum schum., a c4 plant with low phenol-oxidase activity, were enzymatically separated according to methods recently developed with sugarcane (saccharum officinarum l.), maize (zea mays l.), and sorghum (sorghum bicolor l.). the phosphoenolpyruvate carboxylase and nadp-malic dehydrogenase of the c4 pathway were found to be localized in the mesophyll protoplasts while ribulose-1,5-diphosphate (rudp) carboxylase, phosphoribulokinase ...	1974	24442563
formation of c-4 dicarboxylic acids by intact spinach chloroplasts.	it is concluded from (14)c labelling kinetics as well as from enzyme analysis that formation of malate and aspartate from glycerate-3p via carboxylation of p-enolpyruvate occurs in isolated photosynthesizing spinach (spinacia oleracea l.) chloroplasts. carbon incorporation into both dicarboxylic acids was about 1% of the total co2 fixation. both acids are suggested to act as substrates for counter exchange for glutamate and α-ketoglutarate.	1975	24435300
a sulfotransferase from spinach leaves using adenosine-5'-phosphosulfate.	active sulfotransferase can be extracted from spinach (spinacea oleracea l.) leaves (and other higher plants) using a buffer system containing 0.1 m kcl and thiol reagents. this sulfotransferase is labile, it can, however, be stabilized by storage in 70% ammonium sulfate containing 10 mm mercaptoethanol. this extract will reduce labelled adenosine-5'-phosphosulfate (aps) and 3'-phosphoadenosine-5'-phosphosulfate (paps) to acid-volatile radioactivity when dithioerythrol is added. the reduction fr ...	1975	24435265
dark starvation and plant metabolism : iii. co2 fixation and the distribution of radioactive intermediates in leaf discs from spinach plants.	when leaf discs from spinach plants (spinacia oleracea l.) maintained in the dark for several days were subsequently illuminated, the decrease of incorporated (14)co2 measured under steady state conditions was found to be accompanied by an altered fixation pattern. substances found to contain a significantly lower label, were malate and aspartate. in contrast, an enhanced incorporation of radioactivity was observed for those substances known to be formed during light respiration. since the same ...	1975	24435231
dark starvation and plant metabolism : ii. co2 fixation in isolated chloroplasts.	the fixation pattern of radioactive labelled photosynthetic intermediates was followed under steady state conditions during prolonged dark starvation of spinach plants (spinacia oleracea l.). it is suggested that the considerable increase of radioactive dihydroxyacetonephosphate is correlated with a specific leakage of the outer chloroplast envelope induced by dark starvation. the primary fixation product, phosphoglyceric acid, followed the same decreasing tendency as observed for the net co2 fi ...	1975	24435230
lamellar superoxide dismutase of isolated chloroplasts.	photooxidation of hydroxylamine to nitrite by spinach (spinacia oleracea l. and sugarbeet (beta vulgaris l.) chloroplast lamellae in the presence of autoxidable electron acceptors is inhibited by either solubilized or membrane-bound superoxide dismutase (sod). this inhibition is reversed by kcn. the rates of hydroxylamine photooxidation by chloroplast lamellae, a reaction which is apparently driven by the superoxide free-radical ion, was used for quantitating the amount of sod bound to chloropla ...	1975	24435081
protection of photosynthetic o2 evolution against heat inactivation: the role of chloride, ph and coupling status.	heat inactivation of photosynthetic o2 evolution was studied in isolated thylakoids from spinach (spinacia oleracea) and mangrove (avicennia marina) leaves. different temperatures, salt, ph and uncoupler effects were investigated. from these results and others in the literature it was concluced that chloride loss from the membrane and, more specifically, the oxygen-evolving complex of photosystem ii, may be the cause of inhibition of oxygen evolution during heat inactivation.	1988	24430859
hydrogen peroxide production and the release of carbon dioxide during glycollate oxidation in leaf peroxisomes.	the rate at which h2o2 becomes available during glycollate oxidation for further oxidation reactions, especially that of glyoxylate to formate and co2, in peroxisomes from spinach-beet (beta vulgaris l., var. vulgaris) leaves has been determined by measuring o2 uptake in the presence and absence of added catalase. the rates observed under air and pure o2 were sufficient to account for the (14)co2 released from [l-(14)c]glycollate under these conditions; the two reactions showed similar character ...	1976	24430751
phosphoglycolate phosphatase: purification and preparation of antibodies.	phosphoglycolate phosphatase was partially purified from leaves of nicotiana rustica using ion exchange and chromatofocusing columns. the native molecular weight of the enzyme was determined to be about 58 kd from ferguson plots, with a subunit size of about 32 kd. the native enzyme is thus likely to be a dimer. a polyclonal antibody prepared against the lds denatured enzyme cross reacted with proteins from nicotiana tabacum, glycine max, spinacea oleracea and arabidopsis thaniana. there was lit ...	1987	24430563
relative thermostability of the chloroplast envelope.	intact isolated chloroplasts from leaves of spinacia oleracea l. were subjected to heat treatment. after heating, the integrity of the chloroplast envelopes and the activities of various light-dependent chloroplast reactions were tested. the integrity of the chloroplast envelopes, as judged from rates of ferricyanide reduction, enzyme compartmentation and visual appearance of the chloroplasts in the light microscope with phase optics, was affected much less by heat stress than the photochemical ...	1975	24430479
inhibition of the adenosine-5'-phosphosulfate-sulfotransferase activity from spinach, maize, and chlorella by adenosine-5'-monophosphate.	adenosin-5'-phosphosulfate (aps) sulfotransferase from higher plants and algae seems to be regulated by adenosine-5'-monophosphate, an endproduct of the aps-sulfotransferase reaction. this was found in crude extracts of spinacea oleracea l. and zea mays l. and with partially purified aps-sulfotransferase fractions from chlorella pyrenoidosa. half-maximal inhibition with adenosine-5'-monophosphate, was found to be (a) 1.3 mm for spinacea; (b) 1.3 mm for zea; and (c) 1.6 mm for chlorella. this inh ...	1975	24430289
e88, a new cyclic-di-gmp class i riboswitch aptamer from clostridium tetani, has a similar fold to the prototypical class i riboswitch, vc2, but differentially binds to c-di-gmp analogs.	c-di-gmp has emerged as a ubiquitous second messenger, which regulates the transition between sessile and motile lifestyles and virulence factor expression in many pathogenic bacteria using both rna riboswitches and protein effectors. we recently showed that two additional class i c-di-gmp riboswitch aptamers (ct-e88 and cb-17b) bind c-di-gmp with nanomolar affinity, and that ct-e88 rna binds 2'-f-c-di-gmp 422 times less tightly than class i vc2 rna. based on sequence comparison, it was conclude ...	2014	24430255
value addition of traditional wheat flour vermicelli.	vermicelli is a product prepared by using whole or refined wheat flour. hard dough is prepared, extruded and dried in the sun. since wheat flour is deficient in lysine, one of the essential amino acids, the protein quality remains poor. refining of wheat further reduces nutritional quality. therefore value addition of vermicelli is of prime importance to improve nutrient content and to save its delicacy. secondly, use of value added convenient/processed foods can be a solution to the problem of ...	2013	24425987
the effect of temperature on glycollate decarboxylation in leaf peroxisomes.	[1-(14)c]glycollate was oxidised to(14)co2 by peroxisomes isolated from leaves of spinach beet about 3 times as rapidly at 35°c as at 25°c; the rate was further increased with rise in temperature to a maximum at 55°c. these increases are shown to be mainly due to the increased h2o2 available to oxidise glyoxylate non-enzymically as a result of the higher temperature coefficient of glycollate oxidase activity relative to that of catalase. these results are compared with similar increases in the r ...	1977	24425260
the presence of glutathione and glutathione reductase in chloroplasts: a proposed role in ascorbic acid metabolism.	both glutathione and an nadph-dependent glutathione reductase are present in spinach (spinacia oleracea l.) chloroplasts. it is proposed that glutathione functions to stabilise enzymes of the calvin cycle, and it may also act to keep ascorbic acid in chloroplasts in the reduced form.	1976	24425174
experiments on enzymatic acylation of sn-glycerol 3-phosphate with enzyme preparations from pea and spinach leaves.	optimal reaction conditions were investigated for acylation of sn-[u-(14)c]glycerol 3-phosphate in cell-free systems from leaves of pisum sativum l. and spinacia oleracea l. with palmitoyl-coa as acyl donor the major product formed was monoacyl glycerol phosphate. in pea seedlings enzymatic activity was found to be dependent on the age of shoots going through a maximum 12 days after planting. in such plants the highest enzymatic activity is found in leaves and not in the shoot apex. also in leav ...	1976	24424994
partial purification and properties of adenosine nucleosidase from leaves of spinach beet (beta vulgaris l.).	adenosine nucleosidase (ec 3.2.2.7), which catalyses the irreversible hydrolysis of adenosine to adenine and ribose, has been isolated and purified about 40-fold from leaves of spinach beet (beta vulgaris l.). the enzyme appeared to be specific for adenosine only among the naturally-occurring nucleosides, but comparable activity was also found with adenosine n-oxide. adenosine hydrolysis, which had an optimum at ph 4.5, did not require phosphate ions nor was it stimulated by their presence. the ...	1976	24424769
photosynthetic control, "energy-dependent" quenching of chlorophyll fluorescence and photophosphorylation under influence of tertiary amines.	the effects of the tertiary amines tetracaine, brucine and dibucaine on photophosphorylation and control of photosynthetic electron transport in isolated chloroplasts of spinacia oleracea were investigated. tertiary amines inhibited photophosphorylation while the related electron transport decreased to the rates, observed under non-phosphorylating conditions. light induced quenching of 9-aminoacridine fluorescence and uptake of (14)c-labelled methylamine in the thylakoid lumen declined in parall ...	1989	24424746
oxygen evolving membranes and particles from the transformable cyanobacterium synechocystis sp. pcc6803.	membranes and ps ii particles retaining high rates of o2-evolving activity have been isolated from the transformable cyanobacterium, synechocystis sp. pcc6803. membranes from cells grown under red light exhibit rates of o2-evolution ranging from 500-700 μmole o2/mg chl/h. ps ii particles are prepared by a simple procedure involving deae column chromatography of detergent extracts obtained by simultaneous treatment of membranes with octylglucoside and dodecylmaltoside. the isolated ps ii fraction ...	1989	24424744
the adenosine-5'-phosphosulfate sulfotransferase from spinach (spinacea oleracea l.). stabilization, partial purification, and properties.	adenosine-5'-phosphosulfate (aps) sulfotransferase was purified 25-fold from spinach (spinacea oleracea l.) leaves by sephadex-g-200 gel filtration and chromatography on deae-cellulose. enzyme activity was stabilized with 0.05 m tris-hcl ph 8.0 containing 10 mm mercaptoethanol (me), 10 mm mgcl2, and 30% glycerol. the molecular weight of the aps-sulfotransferase was estimated by gel filtration to be about 110,000 daltons. the enzyme is specific for the sulfonucleotide aps; paps is not a sulfur do ...	1976	24424637
freezing of isolated thylakoid membranes in complex media. v. inactivation and protection of electron transport reactions.	when chloroplast thylakoid membranes isolated from spinach leaves (spinacia oleracea l. cv. monatol) were frozen in media containing the predominant inorganic electrolytes of the chloroplast stroma, linear photosynthetic electron transport became progressively inhibited. after onset of freezing, both psii- and psi-mediated electron flow were inactivated almost to the same extent. prolonged storage of the membranes in the frozen state increased damage to psii relative to psi activity. under these ...	1990	24420991
sulfate and sulfite translocation via the phosphate translocator of the inner envelope membrane of chloroplasts.	the permeability of the inner envelope membranes of spinach (spinacia oleracea) chloroplasts to sulfite and sulfate was investigated in vitro, using the technique of silicone oil centrifugal filtration. the results show that there is a permeability towards both ions, resulting in rates of uptake of about 1.0 (so 3 (2-) ) and 0.7 (so 4 (2-) ) μmol mg chlorophyll(-1) h(-1) respectively (external concentration 2 mmol l(-1)). the rates depend on the external concentration of the anions. anion exchan ...	1977	24420671
qualitative and quantitative immunofluorescence studies of chloroplast ferredoxin : application to investigations of ferredoxin inheritance in nicotiana hybrids.	antibodies were raised in rabbits against 2fe-2s ferredoxin from n. tabacum l. the antibodies showed partial cross-reactivity in the double diffusion test with ferredoxins from spinacia oleracea l., petunia inflata fries., p. axillaris lam., phaseolus vulgaris l., chlamydomonas remhardii dang. a complete cross-reaction was observed with ferredoxins from five other nicotiana species, thus with this test it was impossible to discriminate between these ferredoxins. therefore the following test was ...	1977	24420666
light saturation response of inactive photosystem ii reaction centers in spinach.	the effective absorption cross section of inactive photosystem ii (ps ii) centers, which is the product of the effective antenna size and the quantum yield for photochemistry, was investigated by comparing the light saturation curves of inactive ps ii and active reaction centers in intact chloroplasts and thylakoid membranes of spinach (spinacia oleracea). inactive ps ii centers are defined as the impaired ps ii reaction centers that require greater than 50 ms for the reoxidation of qa (-) subse ...	1990	24420169
effect of fusicoccin on plant cell cultures and protoplasts.	we have assayed the capacity of the fungal toxin fusicoccin to induce some of its characteristic effects (acidification of the medium, stimulation of k(+), and of 3-o-methyl-d-glucose uptake) in cell suspensions of parthenocissus tricuspidata (siebold et zucc.) planchon, acer pseudoplatanus l. and oryza sativa l., and in protoplast suspensions prepared from leaves of nicotiana tabacum l. and spinacia oleracea l. or from cultures of p. tricuspidata. evidence is presented showing that all tested b ...	1977	24420024
subcellular distribution of (35)s-sulfur in spinach leaves after application of (35)so 4 (2-) , (35)so 3 (2-) , and (35)so 2.	(35)so2, (35)so 3 (2-) , and (35)so 4 (2-) , respectively, were applied to leaves of spinacia oleracea l. for 60 min in the light. thereafter, the specific activity was determined in the organelles separated by means of sucrose density gradient centrifugation. in mitochondria and peroxisomes, the specific activity was equally distributed in their protein moieties. after application of (35)so2 or (35)so 3 (2-) , the chloroplast lamellae are characterized by elevated specific activity, which is no ...	1977	24419888
in-vitro interaction between chloroplasts and peroxisomes as controlled by inorganic phosphate.	peroxisomes, whole chloroplasts, mitochondria, and broken chloroplasts of spinach (spinacia oleracea l.), each form 1 band at its typical density, when isolated in sucrose gradients by isopycnic centrifugation in glycylglycine buffer. in potassium-phosphate buffer peroxisomes form a 2nd band at the density of whole chloroplasts. the phosphate effect is half-saturated at a concentration of 10-20 mm. if whole chloroplasts are removed by differential centrifugation before isopycnic centrifugation n ...	1977	24419687
sensitivity of photosynthesis by spinach chloroplast membranes to osmotic stress in vitro: rapid inhibition of o2 evolution in presence of magnesium.	thylakoids prepared from spinach (spinacea oleracea l.) chloroplasts were exposed to osmotic stress in vitro in the presence or absence of different inorganic salts. by an hour after incubation in 1.0 m sorbitol and 10 mm (or more) mgcl2, the thylakoids lost approximately 80% of their photosystem (ps) ii activity, but not ps i. the inhibition occurred only in presence of magnesium as indicated by the combinations of several cations/anions. the ps ii activity was relatively insensitive to osmotic ...	1990	24419656
trace level voltammetric determination of heavy metals and total mercury in tea matrices (camellia sinensis).	an analytical procedure regarding the voltammetric determination of mercury(ii), copper(ii), lead(ii), cadmium(ii) and zinc(ii) by square wave anodic stripping voltammetry (swasv) in matrices involved in food chain is proposed. in particular, tea leaves were analyzed as real samples. the digestion of each matrix was carried out using a concentrated hcl-hno3-h2so4 acidic attack mixture; 0.01 mol l(-1) edta-na2+ 0.15 mol l(-1) nacl + 0.5 mol l(-1) hcl was employed as the supporting electrolyte. th ...	2013	24416778
effect of phosphon-d on photosynthetic light reactions and on reactions of the oxidative and reductive pentose phosphate cycle in a reconstituted spinach (spinacia oleracea l.) chloroplast system.	phosphon-d (tributyl-2, 4-dichlorobenzylphosphonium chloride), known as an inhibitor of gibberellin biosynthesis, enhances photosynthetic electron transport by up to 200%, with fe(cn) 6 (3-) and nadp(+) being the electron acceptors. maximum stimulation is reached at phosphon-d concentrations around 2-5 μm. at the same time photosynthetic atp formation is gradually inhibited. phosphon-d concentrations over 0.1 mm inhibit electron transport. the uncoupling activity of phosphon-d is manifested by i ...	1978	24414777
properties and intracellular distribution of two phosphoglucomutases from spinach leaves.	two isoenzymes of phosphoglucomutase from spinach (spinacia oleracea l.) leaves can be separated by ammonium-sulfate gradient solubilization or deae-cellulose ion exchange chromatography. they were designated as phosphoglucomutase 1 and 2, according to decreasing electrophoretic mobility towards the anode at ph 8.9. phosphoglucomutase 1 is localized in the stroma of the chloroplasts, phosphoglucomutase 2 is a cytosolic enzyme as judged from aqueous cell fractionation studies. both isoenzymes hav ...	1978	24414634
sources of reducing power for nitrate reduction in spinach leaves.	the possible source of nadh, the energy donor for nitrate reductase (ec 1.6.6.1), has been studied using an in vivo assay involving freezing the material (leaves of spinacea oleracea l.) in liquid nitrogen in order to render the tissue permeable to added substrates. glycolysis and the pentose phosphate pathway were capable of generating nadh through glyceraldehyde-3-phosphate dehydrogenase. malate and isocitrate were also capable of generating nadh white other organic acids tested were not, incl ...	1978	24414563
properties and physiological function of a glutathione reductase purified from spinach leaves by affinity chromatography.	glutathione reductase (ec 1.6.4.2) was purified from spinach (spinacia oleracea l.) leaves by affinity chromatography on adp-sepharose. the purified enzyme has a specific activity of 246 enzyme units/mg protein and is homogeneous by the criterion of polyacrylamide gel electrophoresis on native and sds-gels. the enzyme has a molecular weight of 145,000 and consists of two subunits of similar size. the ph optimum of spinach glutathione reductase is 8.5-9.0, which is related to the function it perf ...	1978	24414099
inhibition of photosynthesis and respiration by batatasins.	effects of batatasins i, iii and v, phenolic growth inhibitors occuring in dormant bulbils of dioscorea batatas decne., on photosynthetic reactions of chloroplasts from spinach (spinacia oleracea l.) and on respiration of mitochondria from potatoes (solanum tuberosum l.) were investigated. in chloroplasts, the batatasins effectively inhibited co2-dependent oxygen evolution and electron flow from water to acceptors such as dichlorophenolindophenol, ferricyanide and methylviologen. photosystem-i d ...	1978	24414012
the role of leaves in sex expression in hemp and spinach.	when shoots of young plants of hemp (cannabis sativa l.) and spinach (spinacea oleracea l.) were cultured as cuttings and allowed to regenerate advenitious roots, ca. 80-85% became female (formed pistillate flowers) regardless of whether the leaves were left on the plants or were cut off (except for the 2-3 uppermost ones) after the beginning of adventitious-root formation. but when the leaves were cut off and the cuttings treated with gibberellic acid (ga3, 25 mg/l) ca. 77-80% of the plants bec ...	1979	24408695
localization of adenosine 5'-phosphosulfate sulfotransferase in spinach leaves.	roots of spinach (spinacia oleracea l.) seedlings contained only a very low activity of adenosine 5'-phosphosulfate sulfotransferase compared to the cotyledons. adenosine 5'-phosphosulfate sulfotransferase activity increased about tenfold in cotyledons during greening. preparation of organelle fractions from spinach leaves by a combination of differential and isopycnic density gradient centrifugation showed that adenosine 5'-phosphosulfate sulfotransferase banded with nadp-glyceraldehyde-3-phosp ...	1978	24408467
cell organelles from crassulacean-acid-metabolism (cam) plants : i. enzymes in isolated peroxisomes.	cell organelles were isolated from the cam plants crassula lycopodioides lam., bryophyllum calycinum salisb. and sedum rubrotinctum r.t. clausen by isopycnic centrifugation in sucrose gradients. the inclusion of 2.5% ficoll in the grinding medium proved to be essential for a satisfactory separation of cell organelles during the subsequent centrifugation. peroxisomes, mitochondria, and whole and broken chloroplasts were at least partially resolved as judged by marker-enzyme-activity profiles. the ...	1978	24408466
regulation of photosynthetic electron transport and photophosphorylation in intact chloroplasts and leaves of spinacia oleracea l.	oxygen ist reduced by the electron transport chain of chloroplasts during co2 reduction. the rate of electron flow to oxygen is low. since antimycin a inhibited co2-dependent oxygen evolution, it is concluded that cyclic photophosphorylation contributes atp to photosynthesis in chloroplasts which cannot satisfy the atp requirement of co2 reduction by electron flow to nadp and to oxygen. inhibition of photosynthesis by antimycin a was more significant at high than at low light intensities suggest ...	1978	24408259
o2-dependent inhibition of photosynthetic capacity in intact isolated chloroplasts and isolated cells from spinach leaves illuminated in the absence of co2.	when isolated intact chloroplasts or cells from spinach (spinacia oleracea l.) leaves are incubated in the light in the absence of co2, their capacity for subsequent co2-dependent photosynthetic oxygen evolution is drastically decreased. this inhibition is light and oxygen-dependent and can be prevented by addition of bicarbonate. it is concluded that the normal dissipation of photosynthetic energy by carbon assimilation and in processes related to photorespiration is an essential condition for ...	1978	24408108
effect of growth regulators and role of roots in sex expression in spinach.	when 7-d-old plantlets of spinach (spinacia oleracea l.) were immersed with their roots for 24 h in 25 mg/l gibberellic acid (ga3), or 15 mg/l 6-benzylaminopurine (6-bap), or 15 mg/l indole-3-acetic acid (iaa), or 10 mg/l abscisic acid (aba) and subsequently grown on long (18-h) days, the ratio of plants with male and female flowers, which in the controls was almost 1:1 (48 and 52%, respectively), was greatly altered. the treatments with 6-bap, iaa and aba raised the percentage of female plants ...	1978	24408104
high-frequency oscillations and circadian rhythm of the membrane potential in spinach leaves.	the microelectrode technique was used to follow oscillations in membrane potential in mesophyll cells of spinach (spinacia oleracea l.) during exposure do different photoperiodic conditions. both high-frequency oscillations and circadian variations were observed. the circadian rhythm was imposed on the period of high-frequency oscillation during short days as well as in continuous light: the free-running period was 25.2 h. the average period of high-frequency oscillation increased from 7.64 min ...	1979	24407253
quantifying the sensitivity of scent detection dogs to identify fecal contamination on raw produce.	consumption of raw produce commodities has been associated with foodborne outbreaks in the united states. in a recent centers for disease control and prevention report outlining the incidence of food-related outbreaks from 1998 to 2008, produce of all kinds were implicated in 46% of illnesses and 23% of deaths. methods that quickly identify fecal contamination of foods, including produce, will allow prioritization of samples for testing during investigations and perhaps decrease the time require ...	2014	24405993
n-substituted 5-amino-6-methylpyrazine-2,3-dicarbonitriles: microwave-assisted synthesis and biological properties.	in this work a series of 15 n-benzylamine substituted 5-amino-6-methyl-pyrazine-2,3-dicarbonitriles was prepared by the aminodehalogenation reactions using microwave assisted synthesis with experimentally set and proven conditions. this approach for the aminodehalogenation reaction was chosen due to its higher yields and shorter reaction times. the products of this reaction were characterized by ir, nmr and other analytical data. the compounds were evaluated for their antibacterial, antifungal a ...	2014	24402198
oxalate content of foods and its effect on humans.	oxalic acid and its salts occur as end products of metabolism in a number of plant tissues. when these plants are eaten they may have an adverse effect because oxalates bind calcium and other minerals. while oxalic acid is a normal end product of mammalian metabolism, the consumption of additional oxalic acid may cause stone formation in the urinary tract when the acid is excreted in the urine. soaking and cooking of foodstuffs high in oxalate will reduce the oxalate content by leaching. the mea ...	1999	24393738
a practical approach to minimize the interaction of dietary vitamin k with warfarin.	the many interactions between warfarin and other drugs and foods generate great challenges for clinicians and patients in maintaining stable anitcoagulation. interactions due to variable vitamin k content of different dietary items influence the therapy of nearly all patients on warfarin. unfortunately, there is no widely acceptable, patient-friendly strategy for managing such interactions. in this contribution, we propose a practical approach to managing this troublesome interaction, consisting ...	2014	24383939
molecular approaches toward targeted cancer prevention with some food plants and their products: inflammatory and other signal pathways.	in recent years, there has been growing interest in cancer prevention by food plants and their products. although several plant parts have potentials for chemoprevention and other therapeutic use, their molecular mechanisms of action are not always well understood. extensive research has identified several molecular targets that can potentially be used for the prevention and/or treatment of cancer. in this review, we accumulate evidences of modulating abilities of some dietary plants and their p ...	2014	24377653
using spinach-based sensors for fluorescence imaging of intracellular metabolites and proteins in living bacteria.	genetically encoded fluorescent sensors can be valuable tools for studying the abundance and flux of molecules in living cells. we recently developed a novel class of sensors composed of rnas that can be used to detect diverse small molecules and untagged proteins. these sensors are based on spinach, an rna mimic of gfp, and they have successfully been used to image several metabolites and proteins in living bacteria. here we discuss the generation and optimization of these spinach-based sensors ...	2014	24356773
the genome of the recently domesticated crop plant sugar beet (beta vulgaris).	sugar beet (beta vulgaris ssp. vulgaris) is an important crop of temperate climates which provides nearly 30% of the world's annual sugar production and is a source for bioethanol and animal feed. the species belongs to the order of caryophylalles, is diploid with 2n = 18 chromosomes, has an estimated genome size of 714-758 megabases and shares an ancient genome triplication with other eudicot plants. leafy beets have been cultivated since roman times, but sugar beet is one of the most recently ...	2014	24352233
effect of edta washing of metal polluted garden soils. part ii: can remediated soil be used as a plant substrate?	in a field experiment on metal contaminated and edta-remediated soil we studied plant performance, mycorrhizal associations and prospects of potential re-use of remediated soil as a garden substrate. two experimental plots of 4 × 1 × 0.3 m were filled, one with remediated and the other with original contaminated soil. selected cultivars were rotated over the course of 16months. pb, zn, cd and micronutrient plant uptake was measured and their phytoaccessibility was analyzed by the dtpa method. pl ...	2014	24342493
regio- and stereospecific hydroxylation of various steroids at the 16α position of the d ring by the streptomyces griseus cytochrome p450 cyp154c3.	cytochrome p450 monooxygenases (p450s), which constitute a superfamily of heme-containing proteins, catalyze the direct oxidation of a variety of compounds in a regio- and stereospecific manner; therefore, they are promising catalysts for use in the oxyfunctionalization of chemicals. in the course of our comprehensive substrate screening for all 27 putative p450s encoded by the streptomyces griseus genome, we found that escherichia coli cells producing an s. griseus p450 (cyp154c3), which was fu ...	2014	24334658
clinical efficacy of a herbal dentifrice on dentinal hypersensitivity: a randomized controlled clinical trial.	dentinal hypersensitivity is a common problem and there is a growing interest in herbal based formulations for the treatment of oral diseases. this study was conducted to assess the efficacy of a commercially available novel herbal dentifrice in reduction of dentinal hypersensitivity.	2013	24320906
a survey for isoenzymes of glucosephosphate isomerase, phosphoglucomutase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase in c3-, c 4-and crassulacean-acid-metabolism plants, and green algae.	two isoenzymes each of glucosephosphate isomerase (ec 5.3.1.9), phosphoglucomutase (ec 2.7.5.1), glucose-6-phosphate dehydrogenase (ec 1.1.1.49) and 6-phosphogluconate dehydrogenase (ec 1.1.1.43) were separated by (nh4)2so4 gradient solubilization and deae-cellulose ion-exchange chromatography from green leaves of the c3-plants spinach (spinacia oleracea l.), tobacco (nicotiana tabacum l.) and wheat (triticum aestivum l.), of the crassulacean-acid-metabolism plants crassula lycopodioides lam., b ...	1979	24317570
chloroplast phenylalanine ammonia-lyase from spinach leaves : evidence for light-mediated regulation via the ferredoxin/thioredoxin system.	phenylalanine ammonia-lyase (pal) from spinach (spinacia oleracea l.) leaves was resolved into three forms by diethyl-aminoethyl(deae)-cellulose chromatography. two forms were found in isolated chloroplasts, and the third form (the major component) was located outside of the chloroplasts. one of the chloroplast forms of the enzyme (designated the regulatory form) was activated by reduced thioredoxin. neither the other chloroplast form nor the extra-chloroplast form showed a response to thioredox ...	1979	24317559
modulation of glucose-6-phosphate dehydrogenase by nadph, nadp(+) and dithiothreitol at variable nadph/nadp (+) ratios in an illuminated reconstituted spinach (spinacia oleracea l.) chloroplast system.	the light-dependent inhibition of glucose-6-phosphate dehydrogenase (ec 1.1.1.49), the key enzyme of the oxidative pentose phosphate cycle, can be gradually abolished in an illuminated reconstituted spinach chloroplast system by increasing the concentration of nadp(+). the inhibition caused by the effector which was produced by the system in the light is characterized as being of the competitive type with respect to nadp(+). the ki value is 0.070 mm. the addition of nadph to the illuminated reco ...	1980	24311258
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.	1985	24310941
organization and nucleotide sequence of the genes for spinach chloroplast trna(glu) and trna (tyr.).	the map location and nucleotide sequence of the genes and flanking regions for trnauuc (glu) (trne) and trnagua (tyr) (trny) from spinach (spinacia oleracea) chloroplast dna have been determined. the genes lie approximately midway between the genes for trnaggu (thr) (trnt) and trnaguc (asp) (trnd) on bamh1 fragment 8b, the arrangement being trnt, 458 bp, trne, 64 bp, trny, 409 bp, trnd. trne and trny are encoded by the same dna strand as trnd and the direction of their transcription is divergent ...	1984	24310516
the reactivation of nitrate reductase from spinach (spinacia oleracea l.) inactivated by nadh and cyanide, using trivalent manganese either generated by illuminated chloroplasts or as manganipyrophosphate.	nitrate reductase of spinach (spinacia 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. reactivation was produced with trivalent manganese compounds represented either by manganipyrophosphate or produced by oxidation of mn(2+) ions in the presence of illuminated chloroplasts and compared with reactivation obtained with ferricyanide. reactivation in the chloropla ...	1980	24306689
effects of ph and other factors on the phosphate dependence of photosynthesis in spinach chloroplasts.	chloroplast stromal volume and ph influenced the phosphate (pi)-dependence of photosynthesis of spinach (spinacia oleracea l.) chloroplasts. decreasing the sorbitol concentration in the reaction mixture from 0.35 to 0.25 m, or decreasing the external ph from 8.3 to 7.3, extended the induction period of photosynthesis and decreased both the optimal [pi] and the minimal [pi] required to inhibit o2 evolution completely. at least part of the effect of external ph was attributable to changes in strom ...	1980	24306478
effects of freezing on isolated plant mitochondria.	mitochondria isolated from spinach leaves (spinacia oleracea l.) and potato tubers (solanum tuberosum l.) were partly injured when subjected to freezing for 2 to 4 h at-25°c in salt solutions in the absence of cryoprotectants. damage was manifested by the inactivation of respiratory properties and increase in the permeability of the mitochondrial membranes. decrease in respiratory control indicated that the control mechanism of the electron transport chain was influenced by freezing. oxidative p ...	1981	24302422
adenine nucleotides and energy charge evolution during the induction of flowering in spinach leaves.	changes in adenine nucleotides pool size levels have been investigated in spinach leaves (spinacia oleracea. l. cv. nobel) in order to characterize the transition from the vegetative to the reproductive development. the transient changes reported in this study are the earliest responses observed to date in leaves during photoperiodic induction. these results are discussed in relation to prigogine's theory of systems far from equilibrium.	1981	24302414
an ultrastructural search for lectin-binding sites on surfaces of spinach leaf organelles.	organelles isolated from leaves of spinach (spinacia oleracea l.) were prefixed in glutaraldehyde and then incubated with ferritin conjugates of four lectins - concanavalin a (con a), ricinus communis l. agglutinin, mw 120,000 (rca), soybean agglutinin (sba), and wheat germ agglutinin (wga) - in order to probe their cytoplasmic surfaces for saccharide residues. in each case the major leaf organelles, including microbodies, mitochondria and chloroplast derivatives, failed to exhibit labeling when ...	1981	24302382
characterization of the spinach chloroplast genes for the s4 ribosomal protein, trna(thr) (ugu) and trna (ser) (gga).	the map location and nucleotide sequence of the genes for the s4 ribosomal protein (rps4) and for trna(thr) (ugu) (trnt) and trna(ser) (gga) (trns) on spinach chloroplast dna have been determined. rps4 lies approximately 5 kb 3' to atpbe in the large single copy region and is transcribed in the same direction as atpbe. it has a 178 bp leader sequence, a 603 bp coding region and 620 bp 3' tail. the sequence of the coding region is 83% homologous with that of maize rps4 (29) and the deduced amino ...	1986	24302158
freezing injury in cold-acclimated and unhardened spinach leaves : ii. effects of freezing on chlorophyll fluorescence and light scattering reactions.	leaves from cold-acclimated and from unhardened spinach plants (spinacia oleracea l.) were subjected to a freezing/thawing procedure in which varying minimum temperatures were reached. subsequently, the chlorophyll fluorescence induction signal (kautsky phenomenon) and the light-induced apparent absorbance changes at 535 nm (light-scattering changes indicative of the proton gradient, and absorbance changes induced by the membrane potential) of the leaves were studied to obtain information on the ...	1981	24301977
freezing injury in cold-acclimated and unhardened spinach leaves : i. photosynthetic reactions of thylakoids isolated from frost-damaged leaves.	spinach plants (spinacia oleracea l.) were frost-hardened by cold-acclimation to 1° c or kept in an unhardy state at 20°/14° c in phytotrons. detached leaves were exposed to temperatures below 0°c. rates of photosynthetic co2 uptake by the leaves, recorded after frost treatment, served as a measure of freezing injury. thylakoid membranes were isolated from frost-injured leaves and their photosynthetic activities tested. ice formation occurred at about-4° to-5° c, both in unhardened and cold-accl ...	1981	24301976
photoinhibition of photosystem i electron transfer activity in isolated photosystem i preparations with different chlorophyll contents.	photoinhibition of the light-induced photosystem i (ps i) electron transfer activity from the reduced dichlorophenol indophenol to methyl viologen was studied. ps i preparations with chl/p700 ratios of about 180 (ps i-180), 100 (ps i-100) and 40 (ps i(ha)-40) were isolated from spinach thylakoid membranes by the treatments with triton x-100, followed by sucrose density gradient centrifugation and hydroxylapatite column chromatography. white light irradiation (1.1 × 10(4)μe m(-2) s(-1)) of ps i-1 ...	1996	24301820