text stringlengths 35 50.6k |
|---|
Two homozygous mutant lines of barley (Hordeum vulgare L.) R3202 (Lt1b/Lt1b) and R3004 (Lt2/Lt2), are resistant to lysine plus threonine. They contain aspartate kinase isoenzymes with lost or decreased feedback sensitivity to lysine in either isoenzyme AKII (R3202) or isoenzyme AKIII (R3004). A homozygous double mutant... |
We have examined the induction of carbonic anhydrase activity in Chlamydomonas reinhardtii and have identified the polypeptide responsible for this activity. This polypeptide was not synthesized when the alga was grown photoautotrophically on 5% CO(2), but its synthesis was induced under low concentrations of CO(2) (ai... |
A light-harvesting pigment-protein complex was isolated from the diatom Phaeodactylum tricornutum using the zwitterionic detergent CHAPS (3-[3-cholamidopropyl)dimethylammonio]-1-propanesulfonate). Detergent-solubilized membranes were fractionated by sucrose density gradient centrifugation into three components. The med... |
The relationship between malic acid production and carbon assimilation was examined in the submerged aquatic Crassulacean acid metabolism (CAM) plant, Isoetes howellii Engelmann. Under natural conditions free-CO(2) level in the water was highest at 0600 hours and (14)CO(2) assimilation rates in I. howellii were also hi... |
The imidazolinones, a new chemical class of herbicides, were shown to be uncompetitive inhibitors of acetohydroxyacid synthase from corn. This is the first common enzyme in the biosynthetic pathway for valine, leucine, and isoleucine. The K(i) for the imidazolinones tested ranged from 2 to 12 micromolar. These results ... |
Preincubation of wheat (Triticum aestivum L. Thell.) seedlings in a nutrient solution containing low doses of aluminum (0.5 microgram per milliliter for tolerant cultivar Atlas 66 and 0.1 microgram per milliliter for the sensitive cultivar Grana) enabled substantial root regrowth of varieties grown in a lethal aluminum... |
Chloroplasts of the CD3 wheat mutant were deficient primarily in chlorophyll of light harvesting pigment proteins (LHPP) 1 and 2 and CP1a. The reduced level of protein associated with chlorophyll of LHPP1 and LHPP2 and the reduced level of low molecular weight polypeptides between 23 and 29 kilodaltons confirmed that t... |
Cultured carrot (Daucus carota L.) cells were adapted to growing in 25 millimolar glyphosate by transfer into progressively higher concentrations of the herbicide. Tolerance was increased 52-fold, and the adaptation was stable in the absence of glyphosate. The uptake of glyphosate was similar for adapted and nonadapted... |
The effect of nitrate and ammonium on the extractable activity of two enzymes of assimilatory sulfate reduction, ATP sulfurylase (EC 2.7.7.4) and adenosine 5'-phosphosulfate sulfotransferase (APSSTase), was examined in Lemna minor L. cultivated under steady state conditions. Nitrate reductase (EC 1.6.6.1) was measured ... |
The effect of water stress on glutathione reductase and catalase activities was evaluated in leaf blades of field-grown winter wheat (Triticum aestivum L.). Wheat was sown at two seeding rates under both irrigated and dryland conditions. Flag leaves from dryland plants sown at 60 kilograms/hectare showed no change in e... |
gamma-Guanidinobutyraldehyde dehydrogenase was purified 27-fold in 40% yield from extracts of Vicia faba leaves. High specificity exist only for gamma-guanidinobutyraldehyde and gamma-aminobutyraldehyde; the K(m) value was 3.4 micromolar for gamma-guanidinobutyraldehyde, 25 micromolar for gamma-aminobutyraldehyde, and ... |
Adenylate cyclase, guanylate cyclase, and the cyclic nucleotide phosphodiesterases of Cylindrotheca fusiformis were characterized in crude and partially purified preparations. Both cyclases were membrane-bound and required Mn(2+) for activity, though Mg(2+) gave 50% activity with adenylate cyclase. Properties of adenyl... |
The study aimed to test the hypothesis that ammonia production by Rhizobium bacteroids provides not only a source of nitrogen for growth but has a central regulatory role in maintaining the metabolic activity and functional integrity of the legume nodule. Production of ammonia in intact, attached nodules was interrupte... |
The lipase from the scutella of corn (Zea mays) MO-17 seedlings was purified 272-fold to apparent homogeneity as evidenced by sodium dodecyl sulfate polyacrylamide gel electrophoresis and double immunodiffusion. The procedure involved isolation of the lipid bodies, extraction with diethyl ether, DE-52 ion exchange chro... |
Young, fully expanded leaves from 7-month-old P-deficient citrus rootstock seedlings had levels of nonprotein arginine that were 10- to 50-fold greater than those from P-sufficient control plants. Arginine content of the protein fraction increased 2- to 4-fold in P-deficient leaves. Total arginine content, which averag... |
An experiment was conducted to determine the extent that NO(3) (-) taken up in the dark was assimilated and utilized differently by plants than NO(3) (-) taken up in the light. Vegetative, nonnodulated soybean plants (Glycine max L. Merrill, ;Ransom') were exposed to (15)NO(3) (-) throughout light (9 hours) or dark (15... |
Phytohemagglutinin (PHA), the major seed lectin of the common bean (Phaseolus vulgaris), is found largely in the cotyledons, but is also present in the embryonic axis. At mid-maturation, the percentage of total protein synthesis which is directed towards making PHA is 5 to 10 times greater in the cotyledons than in the... |
Photosystem II (PSII) reaction center core complexes have been isolated and characterized from wild type (WT) Scenedesmus obliquus and from its LF-1 mutant. LF-1 thylakoids are blocked on the oxidizing side of PSII and have a reduced Mn content. Visible absorption and low temperature fluorescence spectra of both core c... |
Rhizopus stolonifer endopolygalacturonase, an elicitor of casbene synthetase activity in castor bean seedlings, was found to be a potent elicitor of the phytoalexin pisatin in pea pods and of proteinase Inhibitor I in tomato leaves. The enzyme was an active elicitor or inducer only in its active native state; heat-dena... |
Six molar urea in sodium dodecyl sulfate-polyacrylamide gels altered the relative electrophoretic mobility of several soybean protein subunits. Glycinin acidic polypeptide components A(3) and A(4) could be resolved from the other acidic polypeptides. A variant of the delta' subunit of beta-conglycinin was identified. |
Glutamine synthetases from roots, nodules, and leaves of Phaseolus vulgaris L. have been purified to homogeneity and their polypeptide composition determined.The leaf enzyme is composed of six polypeptides. The cytosolic fraction contains two 43,000 dalton polypeptides and the chloroplastic enzyme is formed by four 45,... |
The aim of the present investigation was to find factors critical for the co-existence of prolamellar bodies and prothylakoids in etioplasts of wheat (Triticum aestivum L. cv Starke II). The lipid composition of the prolamellar body and prothylakoid fractions was qualitatively similar. However, the molar ratio of monog... |
As starch is the main seed reserve material in both species of Araucaria of South America, A. araucana and A. angustifolia, it is important to understand starch breakdown in both embryo and megagametophyte tissues of Araucaria seeds. Sugar analysis by thin layer chromatography indicates that sucrose is the main sugar p... |
The effects of various chemical treatments upon photosynthesis, soluble leaf protein, CO(2) compensation point, and leaf light transmission in soybean, Glycine max (L.) Merr., seedlings were examined following varying response periods after application at 14 to 17 days postemergence. The compounds N(6)-benzyladenine (B... |
Constitutive arginase (molecular weight 330,000) 920-fold purified from Evernia prunastri thallus, is activated by putrescine, l-ornithine, and agmatine with K(a) values of 2.7, 1.1, and 5.8 millimolar, respectively. Constitutive arginase is also activated by endogenous l-arginine, reaching its maximum activity at 16 h... |
Soybean lipoxygenases-1 and -2 were localized intracellularly in seeds at various stages of germination by indirect labeling of cryosections with protein A-colloidal gold complexes. Two sizes of gold particles (Au(5) and Au(16)) were used in single- and double-labeling experiments. In primary leaves, lipoxygenases are ... |
Two distinct processes are involved in the formation of active hydrogenase during anaerobic adaptation of Chlamydomonas reinhardtii cells. In the first 30 minutes of anaerobiosis, nearly all of the hydrogenase activity can be attributed to activation of a constituitive polypeptide precursor, based on the insensitivity ... |
Preliminary results from differential centrifugation experiments, washing treatments, and enrichment in linear sucrose gradients at a density of 1.09 grams per cubic centimeter all indicated that beta-glucosidase activity in corn root homogenates was associated with a membrane such as tonoplast. A subsequent sucrose de... |
The subcellular localizations of the Dolichos biflorus seed lectin and the structurally related lectin (cross-reactive material [CRM]) from the stems and leaves of this plant were determined by immunofluorescence, immunocytochemistry, and cell fractionation procedures. Subcellular fractionation of the cotyledons using ... |
Vacuoles isolated from Nicotiana rustica var brasilia have been shown to contain significant levels of glycosidase activity when assayed using p-nitrophenyl-glycosides as substrates. The substrate specificity for the glycosidases in the vacuolar fraction closely paralleled that found in the protoplasts, and the leaf ti... |
Previous work in our laboratory (Krueger, Miles 1981 Plant Physiol 68: 1110-1114) indicated that a decaploid genotype (I-16-2) of tall fescue (Festuca arundinacea Schreb.) which exhibits unusually high net photosynthesis rates also had high potential rates of photosynthetic electron transport through photosystem I (PSI... |
The activity of sucrose-phosphate synthase (SPS) in 9-day-old barley (Hordeum vulgare L.) primary leaves was measured over a 24-hour period. Extractable enzyme activity was constant in the light, decreased 50 to 60% during the first one-half hour of darkness, and then returned to full activity before the start of the n... |
In the cotyledon extracts of seedlings of many oil seeds, including soybean, sunflower, cucumber, and peanut, the in vitro lipase activity was too low to account for the observed in vivo lipolysis. The low in vitro lipase activity was due to the presence of lipase inhibitors in the extracts. The inhibitors from soybean... |
In the eukaryotic and unicellular alga Cyanidium caldarium the synthesis of the plastid enzyme ribulose bisphosphate carboxylase/oxygenase (RuBPCase) and the light gathering proteins phycocyanin (PC) and allophycocyanin (APC) is under the control of light and glucose, which is a metabolizable carbon source for this org... |
The interacting effects of the rate of ribulose 1,5-bisphosphate (RuBP) regeneration and the rate of RuBP utilization as influenced by the amount and activation of RuBP carboxylase on photosynthesis and RuBP concentrations were resolved in experiments which examined the kinetics of the response of photosynthesis and Ru... |
The characteristics of Ca(2+) transport into endoplasmic reticulum vesicles isolated from roots of Lepidium sativum L. cv Krause have been investigated. The concentration of free Ca(2+) and ATP needed for half-maximal activity were 2.5 and 73 micromolar, respectively, and the enzyme obeyed Michaelis-Menten-like kinetic... |
Callus tissue cultures were developed from apical meristem regions of tumor-like ineffective root nodules of alfalfa. Callus growth was a function of tissue source and hormone composition and concentration. Callus derived from ineffective nodules also were shown not to contain Rhizobium meliloti.Glutamate dehydrogenase... |
The accumulation of the isoflavonoid phytoalexin, glyceollin, occurs in hypocotyls of green soybean seedlings (Glycine max L. Merr. cv Harosoy 63) in response to the injection of a glucan elicitor isolated from the mycelial walls of the fungus, Phytophthora megasperma f. sp. glycinea. This accumulation, which levels of... |
Constitutively produced extracellular pectinesterases from culture filtrates of the potato late blight fungus Phytophthora infestans were purified and characterized. One enzyme (PE II) was purified to homogeneity. Sodium dodecyl sulfate electrophoresis of the second enzyme (PE I) revealed two protein bands; there are i... |
Cytidine 5'-triphosphate (CTP):phosphatidate cytidyltransferase from the endoplasmic reticulum and mitochondria of Ricinus communis L. var Hale was characterized. The endoplasmic reticulum enzyme has a pH optimum of 6.5 and a divalent cation is required, Mn(2+) being preferred and giving maximum activity at 2.5 millimo... |
Nitrate reductase was purified about 3,000-fold from spinach leaves by chromatography on butyl Toyopearl 650-M, hydroxyapatite-brushite, and blue Sepharose CL-6B columns. The purified enzyme yielded a single protein band upon polyacrylamide gel electrophoresis under nondenaturing conditions. This band also gave a posit... |
The metabolism of allantoin by immature cotyledons of soybean (Glycine max L. cv Elf) grown in culture was investigated using solid state (13)C and (15)N nuclear magnetic resonance. All of the nitrogens of allantoin were incorporated into protein in a manner similar to that of each other and to the amide nitrogen of gl... |
Different methods for the isolation of soluble proteins were applied to cell cultures of three apple cultivars (Malus sylvestris Mill.), best results being obtained with a rapid technique based on freezing and thawing. Ultrathin-layer isoelectric focusing followed by an improved silver staining method has shown that pr... |
During male gametophyte development the synthesis of several proteins occurs from transcripts of the haploid genome. Alcohol dehydrogenase (ADH1), a developmentally regulated protein, was chosen for study to determine the stage at which its synthesis was initiated and the pattern of its synthesis during microsporogenes... |
The synthesis of beta-galactosidase during Brassica campestris pollen development results from the transcription of the haploid genome. A quantitative cytochemical method has been developed in which 5-bromo-4-chloro-3-indoxyl-beta-d-galactoside is used as substrate giving a blue-green final reaction product. We have re... |
The interaction of ferredoxin-NADP reductase (FNR) and ferredoxin (Fd) results in an enhanced rate of reaction and a shift of the pH optimum for the FNR-mediated diaphorase reaction. Low concentrations of NaCl (<100 millimolar), favorable for formation of the FNR:Fd complex, further magnify the alteration of the diapho... |
Soybean (Glycine max L. Merr.) leaves contain two forms of nitrate reductase (NR)-NAD(P)H:NR and NADH:NR. Wild-type (cv Williams), nr(1) mutant and an unrelated cultivar (Prize) were grown with either no N source or with nitrate. Crude extracts were assayed for NR activities and the enzyme forms were purified on blue S... |
Organic gelling agents such as agar and agarose provide a heterotrophic substrate for growth of illuminated tobacco callus. When green cells are incubated in CO(2)-free air on a medium lacking sucrose but solidified with 1% agar, an increase in relative dry weight is sustained through two passages. Similar results with... |
Corn was grown under greenhouse and controlled light quality conditions incluing full spectrum, red (R), and far-red (FR) sources. Young leaf samples were analyzed for pigments, pigment-proteins, membrane polypeptides, and ultrastructure. Chloroplast development in full spectrum white light was similar to that found in... |
The substrate and ionic requirements of ATP and inorganic pyrophosphate (PPi) hydrolysis by tonoplast vesicles isolated from storage tissue of red beet (Beta vulgaris L.) were compared with the requirements of ATP-and PPi-dependent proton translocation by the same material. Both ATP hydrolysis and ATP-dependent proton ... |
Membranes enriched in ATP-dependent proton transport were prepared from suspension cultures of tomato cells (Lycopersicon esculentum Mill cv VF36). Suspension cultures were a source of large quantities of membranes from rapidly growing, undifferentiated cells. Proton transport activity was assayed as quench of acridine... |
Comparison of two-dimensional polyacrylamide gel electrophoretic maps of proteins isolated from benzyladenine-treated and untreated pumpkin (Cucurbita pepo L. cv Halloween) cotyledons showed that the expression of certain proteins is enhanced, induced, or suppressed by the cytokinin treatment. The amount of poly(A)(+) ... |
The allocation and turnover of photosynthetically assimilated (14)CO(2) in lipid and protein fractions of soybean (Glycine max L. Clark) leaves and stem materials was measured. In whole plant labeling experiments, allocation of photosynthate from a pulse of (14)CO(2) into polymeric compounds was: 25% to proteins in 4 d... |
Experiments were conducted with soybean (Glycine max [L.] Merr. cv ;Ransom') plants to determine if diurnal rhythms in net carbon dioxide exchange rate (CER), stomatal resistance, and sucrose-phosphate synthase (SPS) activity persisted in constant environmental conditions (constant light, LL; constant dark DD) and to a... |
The novel sucrose derivative 1'-fluorosucrose (alpha-d-glucopyranosyl-beta- d-1-deoxy-1-fluorofructofuranoside) was synthesized in order to help define mechanisms of sucrose entry into plant cells. Replacement of the 1'-hydroxyl by fluorine very greatly reduces invertase hydrolysis of the derivative (hydrolysis at 10 m... |
Photoactivation of phosphoenolpyruvate carboxylase in C(4) plants is detected more efficiently when activity is assayed at suboptimum pH (e.g. 7.2); the magnitude of the light effect is often larger at low phosphoenolpyruvate concentration.Darkness and low assay pH induce an allosteric behavior (positive cooperativity ... |
Steady state rates of NADP reduction decline upon commencement of nitrite reduction in reconstituted chloroplast preparations. Similarly, steady state rates of nitrite reduction are lower, but not zero, during concurrent NADP reduction. These results imply that competition for substrate occurs and suggest that nitrite ... |
The activation and catalytic mechanism of corn mitochondrial F(1) were examined for the two distinct forms of the enzyme which appear upon storage in ammonium sulfate or glycerol. Apparently irreversible differences in the stability of the two active forms were found. Nucleosidetriphosphate induced activation of the en... |
Corn mitochondrial F(1)-ATPase was purified from submitochondrial particles by chloroform extraction. Enzyme stored in ammonium sulfate at 4 degrees C was substantially activated by ATP, while enzyme stored at -70 degrees C in 25% glycerol was not. Enzyme in glycerol remained fully active (8-9 micromoles P(i) released ... |
The aim of this work was to examine the possibility that fructose 2,6-bisphosphate (Fru-2,6-P(2)) plays a role in the regulation of gluconeogenesis from fat. Fru-2,6-P(2) is known to inhibit cytoplasmic fructose 1,6-bisphosphatase and stimulate pyrophosphate:fructose 6-phosphate phosphotransferase from the endosperm of... |
The ability of the wheat germ initiation factors and ribosomes to serve as substrates for a wheat germ protein kinase (Yan and Tao 1982 J Biol Chem 257: 7037-7043) has been investigated. The wheat germ kinase catalyzes the phosphorylation of the 42,000 dalton subunit of eukaryotic initiation factor (eIF)-2 and the 107,... |
Budgets for import and utilization of ureide, amides, and a range of amino acids were constructed for the developing first-formed fruit of symbiotically dependent cowpea (Vigna unguiculata [L.] Walp. cv Vita 3). Data on fruit total N economy, and analyses of the xylem and phloem streams serving the fruit, were used to ... |
The transverse heterogeneity of the polypeptides associated with the Photosystem I (PSI) complex in spinach thylakoid membranes and in a highly resolved PSI preparation has been studied using the impermeant chemical modifier, 2,4,6-trinitrobenzenesulfonate (TNBS) and the proteolytic enzyme, Pronase E. The present study... |
The intact fruits of preclimacteric tomato (Lycopersicon esculentum Mill) or cantaloupe (Cucumis melo L.) produced very little ethylene and had low capability of converting 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene. When these unripe tomato or cantaloupe fruits were treated with ethylene for 16 hours ther... |
Light or dark grown Euglena gracilis strains contain similar levels of glutathione (GSH) peroxidase. Cells in midstationary phase of growth contained the highest level of the enzyme. The enzyme was purified 280-fold to homogeneity from the permanently bleached strain, E. gracilis var bacillaris W(3)BUL. The native enzy... |
Administration of methionine to growing Lemna had essentially no effect on accumulation of sulfate sulfur in protein cysteine, but decreased accumulation into cystathionine and its products (homocysteine, methionine, S-methylmethioninesulfonium salt, S-adenosylmethionine, and S-adenosylhomocysteine) to as low as 21% th... |
A number of proteins that accumulate in vacuoles and protein bodies undergo posttranslational processing at these accumulation sites. These processing steps include proteolytic cleavage (e.g. pea lectin, soybean glycinin, and rice lectin) and the removal of some sugar residues from oligosaccharide side-chains (e.g. bea... |
The fate of glutamine, the major source of nitrogen supplied to the developing maize endosperm, has been examined in endosperm tissues of corn caryopsis grown under sterile conditions. In the culture system, [U-(14)C]glutamine was included in the medium or was injected directly into the endosperm. Samples were harveste... |
In soybean seeds the level of hydroxyproline is regulated in a developmental and tissue-specific manner. The seed coat contains approximately 77% of the total hydroxyproline in the seed at all stages of development. We determined the ratio of hydroxyproline to dry weight in a number of tissues within the seed; however,... |
A new method for the rapid and quantitative fluorometric determination of callose is described. In suspension-cultured cells of Glycine max, synthesis of callose starts within 20 minutes of treatment with chitosan and parallels over hours the accumulation of 1,3-linked glucose in the wall. Poly-l-lysine also elicits ca... |
The CO(2)/O(2) specificity factor of sucrose gradient purified ribulose 1,5-bisphosphate carboxylase/oxygenase from the C(3)-C(4) intermediate plants Moricandia arvensis (79 +/- 1) and Panicum milioides (89 +/- 2) was similar to the respective values of the enzyme from the closely related C(3) species, Moricandia foeti... |
Wheat leaves (Triticum aestivum L.) at the moment of their maximum expansion were detached and put in darkness. Their protein, RNA and DNA contents, as well as their rates of protein synthesis and degradation, were measured at different times from 0 to 5 days after detachment. Rates of protein synthesis were measured b... |
The objective of this study was to determine the biochemical basis for genetic variability in pyruvate,Pi dikinase (PPDK) activity among inbred lines of maize (Zea mays L.). Although in vitro PPDK activity varied more than 5-fold among eight maize inbreds, immunochemical determinations of the proportion of leaf soluble... |
Biochemists who study single cells have been constrained by the lack of a general methodology of high time resolution and high measurement sensitivity for quantitatively assaying enzyme activities using natural substrates in solution. The methods we describe will remove this limitation. In brief, nanogram tissue sample... |
Phosphoenolpyruvate carboxylase appears to be located in or associated with the chloroplasts of Crassula. As has been found with this enzyme in other CAM plants, a crude extract of leaves gathered during darkness and rapidly assayed for phosphoenolpyruvate carboxylase (PEPc) activity is relatively insensitive to inhibi... |
Some properties of ornithine carbamoyltransferase from chloroplasts isolated from leaves of Pisum sativum L. (cv Marzia) were compared with those of the enzyme partially purified (316-fold) from shoots of seedlings after 3 weeks of cultivation.Both preparations showed a pH optimum at pH 8.3 and had the same affinity to... |
Cultures of soybean cells incorporate [5,6-(3)H]-l-fucose into various cellular components including lipids and proteins. The membrane glyco-proteins were digested with pronase to produce glycopeptides, and the glycopeptides were isolated on columns of Biogel P-4. The major fucoselabeled glycopeptide sized as a Hexose(... |
Treatment of melon hypocotyls or petioles with an elicitor from Colletotrichum lagenarium, a fungal pathogen of melons, causes an initial transitory inhibition of protein synthesis and, after 18 hours, induces the synthesis of a plant cell wall hydroxyproline-rich glycoprotein (HRGP). Microgram amounts of elicitor are ... |
Changes in the amounts of thylakoid galactolipids and proteins were monitored for 96 hours following iron resupply to iron-deficient sugar beet (Beta vulgaris L. cv F58-554H1) plants. During this period of iron nutrition-mediated chloroplast development, the amount of galactolipid per leaf area increased linearly with ... |
In vitro studies to explore the biosynthesis of 11S globulin developing cotyledons of pumpkin (Cucurbita sp.) demonstrated that 11S globulin is synthesized on membrane-bound polysomes. M(r) of the translation products (preproglobulin) synthesized by the poly(A)(+)-RNA isolated from developing cotyledons were determined... |
The kinetics and inhibitor specificities of phosphate transport across the plasma membrane of wheat leaf mesophyll protoplasts have been examined. Studies were also carried out on the effects of light and pH on phosphate transport and the plasma membrane electropotential. At pH 5.8 (30 degrees C), protoplasts accumulat... |
We have found nuclear, recessive mutants in Zea mays L. where assembly of the major chlorophyll (a/b) light-harvesting complex (LHC) was not delayed relative to most other thylakoid protein complexes during thylakoid biogenesis. This contrasts with the normal development of maize chloroplasts (NR Baker, R Leech 1977 Pl... |
Two-dimensional gel electrophoresis resolves total cellular protein from Euglena gracilis klebs var bacillaris Cori into 640 polypeptides, 79 of which are induced by light exposure. The inhibition of chloroplast translation by streptomycin, the direct inhibition of photosynthesis as well as the indirect inhibition of c... |
After dark-light transitions, there is a delay in photosynthetic CO(2) fixation by isolated pea chloroplasts in the range of some minutes. In order to assess the physiological significance of light modulation of enzyme activity in the control of induction, we made estimates of the kinetic parameters of fructose-1,6-bis... |
Glycosyl transferases that participate in the assembly of the lipid-linked oligosaccharide intermediates were solubilized from cultured soybean cells using 0.3% Nonidet P-40 (NP-40) in the presence of 10% glycerol. The solubilized enzyme preparation was reasonably stable and 50% of the activity still remained after sto... |
Leaf photosynthesis and ribulose bisphosphate carboxylase activation level were inhibited in several mutants of the C(3) crucifer Arabidopsis thaliana which possess lesions in the photorespiratory pathway. This inhibition occurred when leaves were illuminated under a photorespiratory atmosphere (50% O(2), 350 microlite... |
An anion-sensitive ATP-dependent H(+) transport in microsomal membranes from Zea mays L. coleoptiles was partially characterized using the pH gradient-dependent decrease of unprotonated neutral red. The following criteria strongly suggest a tonoplast origin of the H(+) transport observed: strict dependence on Cl(-); in... |
We have investigated the accumulation and intracellular localization of soybean (Glycine max [L.] Merr. cv Forrest) alpha-galactosidase-hemagglutinin during seed development. Cotyledon tissue was embedded in Lowicryl K4M and immunocytochemical localization was accomplished through treating thin sections with alpha-gala... |
Mutants of sweetclover (Melilotus alba) with defects in the nuclear ch5 locus were examined. Using thin-layer chromatography and absorption spectroscopy, three of these mutants were found to lack chlorophyll (Chl) b. One of these three mutants, U374, possessed thylakoid membranes lacking the three Chl b-containing pigm... |
A method was developed for the isolation of vacuoles from the mesophyll protoplasts of spinach leaf, employing the discontinuous Ficoll density gradient centrifugation technique. Isolated vacuole preparations were judged to be free from other organellar fractions based on the assays of marker enzyme activities of indiv... |
Endosperms from castor beans (Ricinus communis) germinated for 0 to 6 days were exposed to anoxia for 0 to 15 hours. Ethanol, the only alcohol detected by gas chromatography in the tissue, accumulates to a concentration of 15 millimolar during the first 2 to 4 hours of anoxia and subsequently decreases. The absolute am... |
Activities catalyzing the synthesis of fructose-2,6-bisphosphate (fructose-6-phosphate,2-kinase or Fru-6-P,2K) and its breakdown (fructose-2,6-bisphosphatase or Fru-2,6-P(2)ase) were identified in leaves of corn (Zea mays), a C(4) plant. Fru-6-P,2K and Fru-2,6-P(2)ase were both localized mainly, if not entirely, in the... |
Vacuoles were isolated from corn coleoptile protoplasts and ATP-dependent proton transport was measured by quinacrine fluorescence quenching or by the uptake of [(14)C]methylamine. Intact vacuoles were judged to be free of a surrounding plasma membrane based on fluorescent staining with fluoroscein-diacetate. Essential... |
Proteolysis of ribulose bisphosphate carboxylase (RuBPCase) during senescence was monitored using oat leaf segments (Avena sativa cv Victory), kept in the dark. We here report the development of a novel approach for measuring protein degradation of endogenous substrates both in situ and in vitro in crude extracts using... |
Mature soybean (Glycine max L. cv Harosoy 63) leaves normally contain kaempferol-3-glycosides but they accumulate no other flavonoids. Whole leaves sprayed with the diphenyl ether herbicide Acifluorfen and maintained in the light developed small necrotic lesions and accumulated isoflavone aglycones, isoflavone glucosid... |
Ribulose 1,5-bisphosphate carboxylase (RuBPCase) was chosen as a model protein to study how heat shock (HS) affects both chloroplast protein synthesis and the nuclear-chloroplast interaction in production of chloroplast proteins. Experiments were performed using highly chlorophyllous, soybean (Glycine max L. Merr. var ... |
SUCROSE SYNTHASE (UDPGLUCOSE: d-fructose 2-alpha-d-glucosyl transferase, EC 2.4.1.13) has been purified from the plant cytosolic fraction of soybean (Glycine max L. Merr cv Williams) nodules. The native enzyme had a molecular weight of 400,000. The subunit molecular weight was 90,000 and a tetrameric structure is propo... |
A study was made of the influence of wounding on the senescence of standard oat leaf segments in the dark. Wounding was by either subdividing the 3 centimeter long segments into 5 millimeter subsegments, gently scraping the adaxial surface of the segments with a sharp blade, making transverse linear cuts, or by making ... |
Subterranean clover (Trifolium subterraneum L. cv Seaton Park) was grown in solution cultures containing adequate nitrogen both with and without Cu. After Cu deficiency had developed, Cu(2+) was added to some deficient plants and Cu content, protein content, and activities of three Cu metalloenzymes (diamine oxidase [E... |
Metabolism of abscisic acid (ABA) was investigated in isolated guard cells and in mesophyll tissue of Vicia faba L. and Commelina communis L. After incubation in buffer containing [G-(3)H]+/-ABA, the tissue was extracted by grinding and the metabolites separated by thin layer chromatography. Guard cells of Commelina me... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.