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The alcohol dehydrogenase (ADH) inactivator from aerobically grown rice (Oryza sativa) coleoptiles was shown to be associated with membranes which were recovered in sucrose gradients at peak density 1.13 grams per cubic centimeter. When Mg(2+) was included in the gradient, the inactivator was recovered at peak density ... |
The roots of maize (Zea mays L. var LG11) seedlings were watered with a solution of Tridemorph (2,6-dimethyl-N-tridecyl-morpholine), a systemic fungicide, for 3 to 4 weeks from the onset of germination. Very few big up tri, open(5)-sterols, the major sterols of the control, were detected in the treated plants, and 9bet... |
The mechanism for decarboxylating the carboxyl carbon of glycolate was studied in Euglena gracilis Z, which liberates more than 70% of the carboxyl carbon as CO(2) during glycolate metabolism.In the isolated mitochondria of E. gracilis, glycolate was oxidized to glyoxylate, 25% of which was aminated to glycine, with th... |
Root nodules were harvested from chamber-grown soybean (Glycine max L. Merrill cv Woodworth) plants throughout development. Apparent nitrogenase activity (acetylene reduction) peaked before seeds began to develop, but a significant amount of activity remained as the seeds matured. Nodule senescence was defined as the p... |
Variations in leaf starch accumulation were observed among four species (wheat [Triticum aestivum L.], soybean [Glycine max L. Merr.], tobacco [Nicotiana tabacum L.], and red beet [Beta vulgaris L.]), nine peanut (Arachis hypogea L.) cultivars, and two specific peanut genotypes grown under different nutritional regimes... |
Porphobilinogen oxygenase, skatole pyrrolooxygenase, and tryptophan pyrrolooxygenase were found in the different parts of germinating wheat (Triticum aestivum) grain seedlings. In the embryos of grains germinated for 24 hours, the activities of PBG oxygenase and skatole pyrrolooxygenase were inhibited by a labile inhib... |
Cotyledons of light-grown soybean (Glycine max L. var Wayne) seedlings were used as a model system to study the possibility that aging requires qualitative changes in protein synthesis. Cotyledons reached a final stage of senescence and then abscised about 22 days after imbibition. Cotyledon senescence was reversed at ... |
The distribution of organelles and associated enzymes between cells containing bacteroids and uninfected cells from nodules of Glycine max L. Merr. cv Amsoy 71 was investigated by separation of protoplasts on a sucrose step-gradient. Infected protoplasts were much larger, irregular in shape, and more dense than uninfec... |
The enzymic oxidation of glycolate to glyoxylate and glyoxylate to oxalate by preparations purified from tobacco (Nicotiana tabacum var Havana Seed) leaves was studied. The K(m) values for glycolate and glyoxylate were 0.26 and 1.0 millimolar, respectively. The ratio of glycolate to glyoxylate oxidation was 3 to 4 in c... |
The indole alkaloid gramine is toxic to animals and may play a defensive role in plants. Under certain conditions, shoots of barley cultivars such as ;Arimar' and CI 12020 accumulate gramine (N,N-dimethyl-3-aminomethylindole) and lesser amounts of its precursors 3-aminomethylindole (AMI) and N-methyl-3-aminomethylindol... |
Activity of 5-methylthioribose kinase, the enzyme which catalyzes the ATP-dependent formation of 1-phospho-5-methylthioribose, has been revealed in the extracts from various higher plant species. Almost 2,000-fold-purified enzyme has been obtained from yellow lupin (Lupinus luteus L. cv Topaz) seed extract. Molecular w... |
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCase) was isolated from isogenic diploid-tetraploid and tetraploid-octoploid sets of alfalfa (Medicago sativa L.) leaves. Molecular weights of RuBPCase subunits were similar across ploidy levels of both isogenic sets with subunits of 52,000 and 14,000. Apparent K(m)(... |
We studied the regulation of 1-aminocyclopropane-1-carboxylate (ACC) synthase activity in tomato (Lycopersicon esculentum Mill.) fruit tissue and attempted the purification of this enzyme. The increase of ACC synthase activity in wounded tomato pericarp was inhibited by cordycepin and cycloheximide. Density labeling st... |
We previously reported that the net photosynthetic rate of a decaploid genotype (I-16-2) of tall fescue (Festuca arundinacea Schreb.) was 32 to 41 versus 22 milligrams CO(2) per square decimeter per hour in a hexaploid genotype (V6-802) (Randall, Nelson, Asay Plant Physiol 59: 38-41). The high rate was later correlated... |
The predominant storage protein of oat (Avena sativa L.) seeds is a saline-soluble globulin with a mol wt of 320,000 which is composed of six large (M(r) = 35,000 to 40,000) and six small (M(r) = 20,000 to 25,000) subunits. Experiments were conducted to further describe the subunit polypeptides and to identify the init... |
Excised soybean (Glycine max [L.] Merrill) cv Anoka leaf discs tend to remain green even after the corresponding intact leaves have turned yello on fruiting plants. We have found that explants which include a leaf along with a stem segment (below the node) and one or more pods (maintained on distilled H(2)O) show simil... |
Glycine decarboxylase has been successfully solubilized from pea (Pisum sativum) leaf mitochondria as an acetone powder. The enzyme was dependent on added dithiothreitol and pyridoxal phosphate for maximal activity. The enzyme preparation could catalyze the exchange of CO(2) into the carboxyl carbon of glycine, the rev... |
Trifluoperazine, a phenothiazine tranquilizer, and tetracaine, a local anesthetic, have been found to inhibit a variety of plant hormone responses at concentrations compatible with their known inhibition of Ca(2+)-calmod-ulin-dependent enzyme activities. Among these responses are cytokinin-dependent betacyanin synthesi... |
Two classes of compounds which bind to calmodulin in a calcium-dependent manner (neuroleptic drugs and local anaesthetics) were used to investigate the possible involvement of a calcium-dependent regulator protein in the action of the plant hormones cytokinins.The cytokinin-induced synthesis of betacyanin in Amaranthus... |
The lipid composition and level of unsaturation of fatty acids has been determined for chloroplast thylakoid membranes isolated from Pisum sativum grown under cold (4 degrees /7 degrees C) or warm (14 degrees /17 degrees C) conditions. Both the relative amounts of lipid classes and degree of saturation were not greatly... |
Light-induced loss of the enzyme protochlorophyllide reductase (EC 1.6.99.1.), already described as a characteristic of whole plants, has now been demonstrated in vitro using etioplast membrane preparations of Avena Sativa L. var Peniarth and Secale cereale L. var Rheidol. Some evidence is presented, based upon tempera... |
The photochemical properties of purified 124 kilodalton (kD) Avena cv Garry phytochrome are examined and compared with those of the proteolytically degraded 118/114 kD species. The proportion of the chromoprotein in the far red absorbing form, Pfr, following saturating red irradiation is 0.86 for 124 kD phytochrome, su... |
Soybean (Glycine max) and pea (Pisum sativum) differ in the transport of fixed nitrogen from nodules to shoots. The dominant nitrogen transport compounds for soybean are ureides, while amides dominate in pea. A possible enzymic basis for this difference was examined.The level of enzymes involved in the formation of the... |
The assay of acetyl-CoA carboxylase (EC 6.4.1.2) does not follow ideal zero-order kinetics when assayed in a crude extract from wheat (Triticum aestivum L.) germ. Our results show that the lack of ideality is the consequence of contamination by ATPase and adenylate kinase. These enzyme activities generate significant a... |
The photosynthetic enzyme ribulose bisphosphate carboxylase-oxygenase [EC 4.1.1.39] (RuBPCase) plays a key role in the carbon reduction system of plants. In this study, we determined the kinetic variability of RuBPCase among 46 varieties of Hordeum vulgare L. at two ages. The V(max) CO(2) and K(m) CO(2) of RuBPCase was... |
The intracellular localization of aryl acylamidase (aryl-acylamide amidohydrolase, EC 3.5.1.13) in rice (Oryza sativa L. var Starbonnet) leaves was investigated. The enzyme hydrolyzes and detoxifies the herbicide propanil (3,4-dichloropropionanilide) thereby accounting for immunity of the rice plant to herbicidal actio... |
The subcellular localization of the enzyme anthocyanin-methyltransferase was studied in cells (protoplasts) obtained from the upper epidermis of petals of Petunia hybrida Hort. Vacuoles were isolated from protoplasts to ascertain the possible presence of the enzyme in these organelles. The recovery of methyltransferase... |
Nitrogenase (EC 1.7.99.2) activity of nodules of cowpea (Vigna unguiculata [L.] Walp), maintained under conditions of a 12-hour day at 30 degrees C and 800 to 1,000 microeinsteins per square meter per second (photosynthetically active radiation) and a 12-hour night at 20 degrees C, showed a marked diurnal variation wit... |
Endopeptidase activity in mature soybean seeds (Glycine max), has been measured using an exogenous substrate, [(125)I]iodoinsulin B chain. On the basis of pH optimum and the use of specific proteinase inhibitors, two distinct endopeptidase activities can be identified in both the embryonic axis and the cotyledons. One ... |
The pathway of phloem unloading and the metabolism of translocated sucrose were determined in corn (Zea mays) seedling roots. Several lines of evidence show that exogenous sucrose, unlike translocated sucrose, is hydrolyzed in the apoplast prior to uptake into the root cortical cells. These include (a) presence of cell... |
Chromatographic and electrophoretic studies have shown that the subunits of the crystalloid protein, isolated from mature castor bean (Ricinus communis L. cv Hale) seed endosperm protein bodies, are heterogeneous with molecular weights in the range 49 to 53.5 kilodaltons (kD), and are quantitatively in unequal amounts.... |
The requirement for the synthesis of RNA and DNA in early germination of wheat (Triticum aestivum var Newana) embryonic axes has been studied by incubating embryos in the presence of appropriate inhibitors and monitoring both embryo growth and the rates of specific metabolic processes. Experiments with 5-fluorouridine ... |
A sensitive and reliable method has been developed for the quantitation of NADP(+)-glutamate dehydrogenase from the phytopathogenic Ascomycete Sphaerostilbe repens using a two-step competitive enzyme-linked immunosorbent assay. Purified enzyme was adsorbed noncovalently to polystyrene wells and rabbit immunserum was al... |
Hydroxypyruvate reductase (HPR), a marker enzyme of peroxisomes, has been purified to homogeneity from cotyledons of light-grown cucumber seedlings (Cucumis sativus var. Improved Long Green). In addition, the peroxisomal location of both HPR and serine-glyoxylate aminotransferase has been confirmed in cucumber cotyledo... |
Mitochondria from castor bean (Ricinus communis cv Hale) endosperm, purified on sucrose gradients, were used to investigate transport of dicarboxylic acids. The isolated mitochondria oxidized malate and succinate with respiratory control ratios greater than 2 and ADP/O ratios of 2.6 and 1.7, respectively. Net accumulat... |
A method for cellular fractionation of Chlamydomonas reinhardii, SAG 11-32/b, and isolation of intact chloroplasts from synchronized cells of the alga is described. The procedure for cell fractionation comprises essentially four steps: (1) protoplast production with autolysine; (2) lysis of the protoplasts with digiton... |
Changes in the levels of twenty-two free amino acids and in the amino acid composition of the total protein were measured throughout the development of cotyledons of a dwarf garden pea, Pisum sativum cv Greenfeast, grown in a constant environment. A sensitive double-isotope dansylation technique was used. Fresh weight,... |
Helminthosporium sacchari produces a host-selective toxin and structurally related nontoxic compounds, here referred to as ;toxoids.' Toxin and the three toxoids were each isolated to a high level of purity and were hydrolyzed under acidic conditions. The released galactose was measured by a galactose oxidase/peroxidas... |
Endoplasmic reticulum membranes stripped of attached ribosomes were isolated from homogenates of germinating castor bean (Ricinus communis L.) endosperm by sucrose density gradient centrifugation. The isolated endoplasmic reticulum fraction was further separated into two major membrane subfractions by centrifugation on... |
Immunohistochemical staining was used to determine the cellular distribution of two glycosylated polypeptides (molecular weights of 27 and 29 kilodaltons) which are normally present at low levels in soybean (Glycine max var ;Wye') leaves but which markedly accumulate after depodding. These polypeptides, which comprise ... |
In spinach (Spinacia oleracea Hybrid 102 [New World seeds]) and wheat (Triticum aestivum L. cv Gabo) leaves, O(2) uptake rates in the dark were faster after the plants had been allowed to photosynthesize for a period of several hours. Alternative path activity also increased following a period of photosynthesis in thes... |
It was previously reported that magnesium ion inhibited carbonic anhydrase (Bamberger and Avron 1975 Plant Physiol 56: 481-485). Studies with partially purified carbonic anhydrase from spinach (Spinacia oleracea L.) chloroplasts show that the effect was the result of the chloride counterion and not the magnesium ion. E... |
Xerosicyos danguyi Humbert (Cucurbitaceae) is a leaf succulent endemic to Madagascar. Under well-watered conditions, the plant exhibited Crassulacean acid metabolism (CAM) but shifted to a dampened form of CAM, CAM-idling, when subjected to water stress. The purpose of this investigation was to examine the effects of a... |
The sensitivity of soybean (Glycine max L. Merr. cv Maple Arrow) seeds to dehydration changed during germination. Seeds were tolerant of dehydration to 10% moisture if dried at 6 hours of imbibition, but were susceptible to dehydration injury if dried at 36 hours of imbibition. Dehydration injury appeared as loss of ge... |
The P(700) chlorophyll alpha-protein was purified by preparative sodium dodecyl sulfate (SDS) gel electrophoresis from SDS-solubilized barley (Hordeum vulgare L., cv Himalaya) chloroplast membranes. After elution from the gel in the presence of 0.05 to 0.1% Triton X-100, the recovered protein had a chlorophyll/P(700) r... |
Cellulase C(1), cellulase Cx, and xylanase were isolated and purified from a cellulase preparation of Trichoderma viride as enzymes effective in the isolation of protoplasts from oat leaves. Pectin lyase which is specific for methyl-galacturonide linkages was also found to be a useful enzyme for the isolation of protop... |
Cabbage (Brassica oleracea var capitata) leaves were used as a source of cystine lyase. Diethylaminoethyl-cellulose chromatography resolved two peaks of activity, designated I and II.Cystine lyase I (molecular weight 145,000) and O-acetylserine sulfhydrylase (molecular weight 70,000) were resolved by Bio-Gel A-0.5M chr... |
The subcellular localization of hexose phosphorylating activity in extracts of pea stems has been studied by differential centrifugation and sucrose density gradient centrifugation. The hexokinase (EC 2.7.1.1) was associated with the mitochondria, whereas fructokinase (EC 2.7.1.4) was in the cytosolic fraction. Some pr... |
Proline accumulation in NaCl-treated excised barley (Hordeum vulgare var Larker) leaves was studied. Leaves were treated by placing the cut end in NaCl solutions and allowing the salt to enter the leaf via the transpiration stream. Leaves treated this way maintained turgor while the sodium content increased and the osm... |
A beta-1,4-xylanase has been purified from the mixture of carbohydrate-degrading enzymes found in a commercial preparation from cultures of Trichoderma viride. Purification from the desalted enzyme mixture is accomplished either by preparative isoelectric focusing or in two-column chromatographic steps. The xylanase ha... |
A series of experiments, with Secale cereale and Triticum aestivum var Argee, to evaluate critically the ability of a malate/aspartate shuttle to provide reducing equivalents to drive hydroxypyruvate reduction to glycerate led to the conclusion that the shuttle, as previously envisioned, does not supply NADH to the per... |
Apple seeds (Malus domestica Borkh. cv Golden Delicious) were stratified at 5 and 15 degrees C for various lengths, weighed, and soluble protein of axis and cotyledon tissue was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Only seeds treated at 5 degrees C germinated; seeds treated at 15 degre... |
The peptidyl prolyl hydroxylase responsible for the formation of hydroxyproline during arabinogalactan-protein biosynthesis in Lolium multiflorum (ryegrass) endosperm cells is a membrane-associated enzyme which will catalyze the hydroxylation of poly(l-proline) in the presence of oxygen, alpha-ketoglutarate, ferrous io... |
Highly purified fractions of three starch branching enzymes from developing maize (Zea mays L.) endosperm were used to prepare antisera in rabbits. In double diffusion experiments, no immunoprecipitate was observed when branching enzyme IIa or IIb was tested against branching enzyme I antiserum. No immunoprecipitate wa... |
Barley (Hordeum distichum cv Klages) kernels were shown to contain a factor that converted malted barley alpha-amylase II to the alpha-amylase III form. After purification by ammonium sulfate fractionation, ion exchange chromatography on DEAE-Sephacel, and gel-filtration on Bio Gel P60, the factor gave a single band of... |
Light stimulates gravitropic bending (downward growth) in roots of many cultivars of corn (Zea mays). In this work, using the cultivar Merit, we show that light stimulates protein synthesis in the root cap, with protein levels increasing 1.3 to 1.6 times that recorded for tissues maintained in continuous dark. Light en... |
When assayed in the presence of azide, NO(3) (-) was shown to be a specific inhibitor of a proton-translocating ATPase present in corn (Zea mays L. cv WF9 x M017) root microsomal membranes. The distribution of the NO(3) (-)-sensitive ATPase on sucrose gradients and its general characteristics are similar to those previ... |
The coordinated synthesis of the subunits of ribulose 1,5-bisphosphate carboxylase was examined by analysis of the chloroplast ribosome-deficient mutant of Chlamydomonas reinhardtii, ac20crl. The absence of the chloroplast-synthesized large subunit of this enzyme from cells of this strain is a direct consequence of the... |
Cell-free preparations of the Crassulacean acid metabolism (CAM) plant, Kalanchoë daigremontiana, were analyzed for thioredoxins and ferredoxin-thioredoxin reductase. Three distinct forms of thioredoxin were identified in Kalanchoë leaves, two of which specifically activated fructose 1,6-bisphosphatase (designated f(1)... |
Accumulation of acid-stable and acid-labile C has been studied in cells isolated from cladophylls of Asparagus sprengeri regel, as a function of the concentrations of the various inorganic C (C(i)) species in the external medium.The rate of CO(2) fixation was higher when C(i) was supplied as CO(2) as opposed to HCO(3) ... |
A novel glucosyltransferase which catalyzed the transfer of glucose from UDP-glucose to positions 2' and 5' of partially methylated flavonols was isolated from the shoots of Chrysosplenium americanum Schwein ex Hooker. It was purified 225-fold by ammonium sulfate precipitation and successive chromatography on Sephadex ... |
The effect of host plant cultivar on H(2) evolution by root nodules was examined in symbioses between Pisum sativum L. and selected strains of Rhizobium leguminosarum. Hydrogen evolution from root nodules containing Rhizobium represents the sum of H(2) produced by the nitrogenase enzyme complex and H(2) oxidized by any... |
The NAD malic enzyme has been purified to near homogeneity from the leaves of Crassula argentea Thunb. The enzyme has two subunits, one of 59,000 daltons, and one of 62,000 daltons. In native gels stained for activity, the enzyme appears to exist in the dimeric, tetrameric, and predominantly the octameric forms.The enz... |
Cell-free extracts from nodules of cowpea (Vigna unguiculata L. (Walp.) cv Caloona:Rhizobium strain CB756) prepared in the presence of 15% (v/v) glycerol showed high rates (30 to 60 nanomoles NAD reduced per minute per gram fresh weight nodule) of inosine monophosphate oxidoreductase (EC 1.2.1.14) activity. The enzyme ... |
Intact plastids from greening maize (Zea mays L.) leaves converted [(14)C]glutamate and [(14)C]2-ketoglutarate (KG) to [(14)C]5-aminolevulinic acid (ALA). Glutamate appeared to be the immediate precursor of ALA, while KG was first converted to glutamate, as shown by the effect of various inhibitors of amino acid metabo... |
DNA-dependent RNA polymerase II (RNAP II) was purified from wheat embryos germinated for 0, 12, 24, and 36 hours and examined with several polyacrylamide gel electrophoretic systems. A changing electrophoretic pattern of RNAP II was observed on nondenaturing polyacrylamide gels. Subunit structure analysis by sodium dod... |
The effects of reduced reaction medium osmotic potential (0.67 molar sorbitol as compared to a control treatment with 0.33 molar sorbitol) on the enzymic steps of the photosynthetic carbon reduction cycle were investigated using isolated spinach (Spinacia oleracea L. var Longstanding Bloomsdale) chloroplasts. Reversal ... |
A study has been made on the State 1-State 2 transitions exhibited by the unicellular green algae Chlorella pyrenoidosa. Chlorophyll fluorescence induction curves from algae adapted to State 1 or State 2 have been analyzed and a comparison made with similar curves produced by decreasing the intensity of light going to ... |
Partially purified intact chloroplasts were prepared from batch cultures of both wild type (Wt) and a mutant strain of Chlamydomonas reinhardtii. Protoplasts were generated from log phase cultures of Wt (137c) and the phosphoribulokinase-deficient mutant F60 by incubation of the cells in autolysine. These protoplasts w... |
Soybean (Glycine max L. Merr) seeds lose their tolerance of dehydration between 6 and 36 hours of imbibition. Soybean axes and cotyledons were excised 6 hours (tolerant of dehydration) and 36 hours (susceptible) after commencing imbibition and subsequently dehydrated to 10% moisture. Kinetics of the efflux of potassium... |
The distribution of diamines, polyamines, and their biosynthetic enzymes arginine decarboxylase and ornithine decarboxylase in roots and coleoptiles of corn (Zea mays var Golden Cross Bantam) seedlings have been determined. Putrescine content, expressed on either a fresh weight or protein basis, increases from the tip ... |
Nitrate and light are known to modulate barley (Hordeum vulgare L.) nitrate reductase activity. The objective of this investigation was to determine whether barley nitrate reductase is regulated by enzyme synthesis and degradation or by an activation-inactivation mechanism. Barley seedling nitrate reductase protein (cr... |
The oxidation isotherms for citrate and isocitrate by potato (Solanum tuberosum var. Russet Burbank) mitochondria in the presence of NAD differ markedly. Citrate oxidation shows positively cooperative kinetics with a sigmoid isotherm, whereas isocitrate oxidation shows Michaelis-Menten kinetics at concentrations up to ... |
The isotherm for isocitrate oxidation by potato (Solanum tuberosum L. var. Russet Burbank) mitochondria in the presence of exogenous NAD is characterized by a hyperbolic phase at isocitrate concentrations below 3 millimolar, and a sigmoid, or positively cooperative phase from approximately 3 to 30 millimolar. The two f... |
Positive phototropism of perithecial beaks in the fungus Neurospora crassa has been demonstrated. The effect was shown to be mediated by blue light. When mutants (white collar-1 and white collar-2) which are blocked in the light induction of enzymes in the carotenoid biosynthetic pathway were used as the protoperitheci... |
Well nodulated, field-grown soybeans (Glycine max [L.] Merr. var Williams) were depodded just prior to seed development and near mid pod-fill. Both treatments caused a considerable increase in leaf dry weight, suggesting continued photosynthate production following pod removal. Moreover, depodding had a marked effect o... |
Removing the pods from soybean (Glycine max [L.] Merr. cv Wye) plants induces a change in leaf function which is characterized by a change in the leaf soluble protein pattern. The synthesis of at least four polypeptides ( approximately 27, 29, 54, and 80 kilodaltons) is enhanced, and these polypeptides accumulate to le... |
Scutella from ungerminated grains of barley (Hordeum vulgare L. cv Pirkka) take up leucine at a slow rate, which increases rapidly during germination. When endosperms were removed from the grains after imbibition for 4 hours or after germination for 12 or 72 hours, the increase in the rate of leucine uptake was greatly... |
Intact and broken (osmotically disrupted) spinach (Spinacia oleracea) leaf peroxisomes were compared for their enzymic activities on various metabolites in 0.25 molar sucrose solution. Both intact and broken peroxisomes had similar glycolate-dependent o(2) uptake activity. In the conversion of glycolate to glycine in t... |
The development of thylakoid stacking, accumulation of the light-harvesting chlorophyll a/b protein complex (LHCP), and the changes of circular dichroism (CD) which reflect the organization of chlorophyll molecules in greening thylakoids of bean Phaseolus vulgaris cv Red Kidney leaves were investigated.Chloroplasts for... |
The starch-granule-bound starch synthase from Zea mays has been solubilized with a recovery of between 50 and 84%. Chromatography of the solubilized enzyme on DEAE-Sepharose resolves two fractions of activity which may be distinguished by their response to citrate. Neither solubilized isoenzyme displays any significant... |
Phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and cardiolipin are the major phospholipids in young leaves of black oak (Quercus robor L.). Except for phosphatidylcholine, young, developing cynipid-galls on black oak leaves, i.e. the insect-transformed tissues, contain less phospholipid than normal... |
THE ACTIVITY OF PYROPHOSPHATE: d-fructose-6-phosphate-1-phosphotransferase (EC 2.7.1.90, PPi-PFK) in cotyledons and sprouts of germinating pea seeds (Pisum sativum cv Alaska or Green Arrow) increases rapidly during the first 2 to 3 days after imbibition and then declines to a lower activity. The reaction toward fructos... |
The chloroplast-associated form of superoxide dismutase from maize (Zea mays L.) (SOD-1) has been purified by a stepwise procedure consisting of (NH(4))(2)SO(4) fractionation, G-100 Sephadex gel filtration, DEAE-Sephacel chromatography, and hydroxylapatite chromatography. This procedure resulted in a single band on sod... |
Uptake of l-[1-(14)C]ascorbate by intact ascorbate-free spinach (Spinacia oleracea L. cv Vital(r)) chloroplasts has been investigated using the technique of silicone oil filtering. Rates greater than 100 micromoles per milligram chlorophyll per hour (external concentration, 10 millimolar) of ascorbate transport were ob... |
Mitochondrial preparations isolated from black gram (Vigna mungo L.) cotyledons exhibited cyanide-resistant respiration which was of mitochondrial origin. The appearance and the disappearance of this alternative respiration took place during and following imbibition. During the first 6 hours of imbibition, the respirat... |
Cytochemical and immunocytochemical methods were used to localize photosystems I and II in barley (Hordeum vulgare L. cv Himalaya) chloroplasts. PSI activity, monitored by diaminobenzidine oxidation, was associated with the lumen side of the thylakoids of both grana and stroma lamellae. The P(700) chlorophyll a protein... |
Polygalacturonase was isolated from cell suspension cultures of a thalloid liverwort, Marchantia polymorpha. The enzyme in the ;buffer-soluble' protein fraction was dialyzed at pH 5.2 and further purified 91-fold by a combination of chromatographic techniques including CM-Sephadex, Sephacryl S-200, DEAE-Sephadex, and S... |
Cells of Anacystis nidulans strain R2 and of Synechococcus cedrorum were grown in an iron-deficient medium. Iron starvation induced several pronounced effects without influencing the viability of these cells. The phycocyanin and chlorophyll contents of these cells were depressed, and the absorption maxima of membrane-b... |
Lipoxygenases 1 and 2 were localized in etiolated germinating soybean seeds (Glycine max [L.]. Merr. var. Williams) by an indirect immunofluorescence staining technique. Sections of paraffin-embedded seedlings were stained with affinity-purified antibodies directed against lipoxygenase 1 or 2. The specificity of the im... |
The effect of proline analogs on peptidyl proline hydroxylation has been studied in vivo using aerated root slices of Daucus carota. One analog, 3,4-dehydroproline, acted at micromolar concentrations to rapidly and selectively inhibit peptidyl proline hydroxylation. A structurally altered hydroxyproline-rich cell wall ... |
Phycobilisomes were isolated from wild type Gracilaria tikvahiae and a number of its genetically characterized Mendelian and non-Mendelian pigment mutants in which the principal lesions result in an increase or decrease in the accumulation of phycoerythrin. Both the size and phycoerythrin content of the phycobilisomes ... |
Nitrogenase (EC 1.7.99.2) activity of a cowpea (Vigna unguiculata (L.) Walp cv Caloona) symbiosis formed with a Rhizobium strain (176A27) lacking uptake hydrogenase and maintained under conditions of a 12-hour day at an air temperature of 30 degrees C (800-1000 microeinsteins per square meter per second) and a 12-hour ... |
Two fractions enriched in plasma membrane derived from suspension-cultured carrot (Daucus carota L.) cells were examined to determine if they differed from each other either in physical nature or in orientation. Parameters studied included the protein composition of purified membranes derived from trypsinized and nontr... |
Two high fluorescent, nuclear recessive mutants of maize (Zea mays L.), designated hcf-2 and hcf-6, are described which are missing the chloroplast cytochrome f/b-563 complex. Thylakoids from the mutants show a block in whole chain electron transport activity (H(2)O to methyl viologen), while retaining activities assoc... |
In the scutella of corn (Zea mays), lipase activity is absent in ungerminated seeds and increases during seedling growth. At the peak stage of lipolysis, about 50% of the lipase activity is recovered in the lipid body fraction after flotation centrifugation. The lipase is tightly bound to the lipid bodies, and resists ... |
Antibodies against the individual subunits of protein complexes in the chloroplast membranes were used to follow the amounts of these polypeptides during foliar senescence. No change was found in the amount of polypeptides of photosystem I reaction center and the chloroplast coupling factor during senescence of oat (Av... |
Arginine is the predominant free amino acid in the cotyledons of developing seeds of Pisum sativum L. cv Marzia. Breakdown of arginine was measured by injecting l-[guanido-(14)C]arginine into detached cotyledons. Cotyledons of developing seeds showed a low rate of (14)CO(2) evolution whereas a much higher rate of (14)C... |
The quantum yield for CO(2) uptake was measured on a number of C(3) and C(4) monocot and dicot species. Under normal atmospheric conditions (330 microliters per liter CO(2), 21% O(2)) and a leaf temperature of 30 degrees C, the average quantum yields (moles CO(2) per einstein) were as follows: 0.052 for C(3) dicots, 0.... |
The mechanism underlying the increase of activity of the three O-methyltransferases of tobacco (Nicotiana tabacum) after infection by tobacco mosaic virus (TMV) has been investigated with a density-labeling method. The three O-methyltransferases from healthy or TMV-infected leaves fed with H(2)O or (2)H(2)O were purifi... |
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