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Treatment of melon leaves or seedlings with elicitors of Colletotrichum lagenarium, a fungal pathogen of melon, increases chitinase activity. In treated leaves, chitinase is enhanced within the first 6 hours and becomes 2 to 10 times higher than in control leaves after 24 hours. Ethylene is increased simultaneously and... |
Extensins are hydroxyproline-rich glycoproteins (HRGPs) found in the primary cell walls of dicots. Extensin monomers are secreted into the wall and covalently bound to each other, presumably by isodityrosine (IDT) cross-links, to form a rigid matrix. Expression of the extensin matrix is correlated with inhibition of ce... |
The quantum yield of photosynthetic O(2) exchange was measured in eight species of leaf succulents representative of both malic enzyme type and phosphoenolpyruvate carboxykinase type CAM plants. Measurements were made at 25 degrees C and CO(2) saturation using a leaf disc O(2) electrode system, either during or after d... |
Phosphoserine aminotransferase activity was detected in the plant and bacteroid fractions from soybean (Glycine max) root nodules. Both total and specific activities increased in the plant fraction during nodule development. Serine-pyruvate aminotransferase activity was not detectable in the plant or bacteroid fraction... |
In vitro culture of pericarp segments from fruit of Citrus sinensis (L.) Osbeck cv Valencia was used to determine the temporal sequence in development of chloroplasts from chromoplasts during regreening of the epicarp. Regreening of chromoplasts closely resembled greening of etioplasts, except that regreening proceeded... |
The functional transition of glyoxysomes to leaf peroxisomes occurs during greening of germinating pumpkin cotyledons (Cucurbita sp. Amakuri Nankin). The immunocytochemical protein A-gold method was employed in the analysis of the transition using glyoxysomal specific citrate synthase immunoglobulin G and leaf peroxiso... |
A simple and rapid technique was developed to synthesize abscisic acid glucose ester. The free acid of abscisic acid (ABA) was combined with CsHCO(3) to form the Cs salt of ABA. The Cs salt of ABA was then combined with acetobromo-alpha-d-glucose tetraacetate, and the tetraacetate derivative of abscisic acid glucose es... |
The metabolism of oleoyl coenzyme A (CoA) was examined in developing seed from two soybean (Glycine max [L.] Merr.) genotypes: Williams, a standard cultivar and A5, a mutant containing nearly twice the oleic acid (18:1) content of Williams. The in vitro rates of esterification of oleoyl-CoA to lysophosphatides by acyl-... |
The expression of phaseolin and phytohemagglutinin (PHA) in the developing cotyledons of a normal (Greensleeves) and a PHA-deficient (Pinto 111) cultivar of Phaseolus vulgaris was investigated. Phaseolin mRNA translational activity and abundance were present at similar levels in both cultivars. In contrast, PHA mRNA tr... |
Changes in the amount of P700-chlorophyll a protein complex, plastocyanin, and cytochrome b(6)/f complex during greening of pea (Pisum sativum L.), wheat (Triticum aestivum L.), and barley (Hordeum vulgare L.) leaves were analyzed by an immunochemical quantification method. Neither subunit I nor II of P700-chlorophyll ... |
A rapid method is described for the preparation of up to 500 milligrams of pure ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBP carboxylase) from 250 grams of field-grown soybean leaves. Leaves were extracted in 20 millimolar phosphate (pH 6.9) at 4 degrees C, containing 4% (w/v) polyvinylpolypyrrolidone, 10 micr... |
The ch4 mutant of sweetclover (Melilotus alba) has previously been demonstrated to be partially deficient in chlorophyll and to have a higher ratio of chlorophyll a to b than normal plants. We were able to substantiate these findings when plants were grown at 23 degrees C and lower (permissive temperatures). However, w... |
Chlorella sorokiniana cells, cultured for 12 hours in 30 millimolar ammonium medium, contained an ammonium inducible nicotinamide adenine dinucleotide phosphate-specific glutamate dehydrogenase (NADP-GDH) isoenzyme with subunits having a molecular weight of 53,000. In vitro translation of total cellular poly(A)(+) RNA,... |
FARNESYL TRANSFERASE (FARNESYL PYROPHOSPHATE: isopentenyl pyrophosphate farnesyl transferase; geranylgeranyl pyrophosphate synthetase) was purified at least 400-fold from extracts of castor bean (Ricinus communis L.) seedlings that were elicited by exposure for 10 h to Rhizopus stolonifer spores. The purified enzyme wa... |
Six monoclonal antibodies against different epitopes of maize leaf nitrate reductase were used to compare plant nitrate reductases in enzyme linked immunosorbent assay and enzyme activity inhibition tests. The number of cross-reacting antibodies was shown to vary with species according to phylogenetic classification, r... |
The microsomal fraction of mung bean seedlings contains mannosidase activities capable of hydrolyzing [(3)H]mannose from the [(3)H]Man(9)GlcNAc as well as for releasing mannose from p-nitrophenyl-alpha-d-mannopyranoside. The glycoprotein processing mannosidase was solubilized from the microsomes with 1.5% Triton X-100 ... |
The evidence presented in this paper suggests that purified plant chromatin, similar to mammalian (SR Umansky et al., Eur J Biochem 1980 105: 117-129), has the ability to incorporate amino acids into acid precipitable material. The polypeptide-synthesizing system of chromatin seems to differ substantially from the clas... |
The ammonium induction of the chloroplast-localized NADP-specific glutamate dehydrogenase (NADP-GDH) was shown not to be a light-dependent process per se in Chlorella sorokiniana. In the dark without exogenous organic substrates, the cells synthesized low levels of fully active NADP-GDH, provided endogenous starch rese... |
The effect of temperature on accumulation of starch was studied in grain slices of wheat (Triticum aestivum cv SUN9E), taken 15 days after anthesis. As compared with pretreatment of such slices at 25 degrees C, pretreatment at 30 or 35 degrees C reduced the subsequent conversion of sucrose to starch. In contrast to ric... |
The [(14)C] moiety from [(3)H]UDP[(14)C]glucose was incorporated by intact cotton fibers into hot water soluble, acetic-nitric reagent soluble and insoluble components, and chloroform-methanol soluble lipids; the [(3)H] UDP moiety was not incorporated. The (3)H-label can be exchanged rapidly with unlabeled substrate in... |
Thin sections of wound-healing potato tuber tissue were stained with rabbit antibody prepared against a suberization-associated anionic peroxidase and then stained with a goat anti-rabbit antibody-fluorescein conjugate. When these sections were examined with an epiilluminating fluorescence microscope, bright green fluo... |
Kernels cultured in vitro were induced to abort by high temperature (35 degrees C) and by culturing six kernels/cob piece. Aborting kernels failed to enter a linear phase of dry mass accumulation and had a final mass that was less than 6% of nonaborting field-grown kernels. Kernels induced to abort by high temperature ... |
A specific polysome immunoadsorption procedure, employing soluble rabbit anti-NADP-GDH IgG and sheep anti-rabbit IgG covalently-linked to an insoluble cellulose matrix, was used to immunoselect polysomes translating mRNA for a chloroplastic ammonium-inducible NADP-GDH in fully induced cells of Chlorella sorokiniana. Th... |
Metabolism of trehalose, alpha,d-glucopyranosyl-alpha,d-glucopyranoside, was studied in nodules of Bradyrhizobium japonicum-Glycine max [L.] Merr. cv Beeson 80 symbiosis. The nodule extract was divided into three fractions: bacteroid soluble protein, bacteroid fragments, and cytosol. The bacteroid soluble protein and c... |
In synchronized Euglena gracilis (light-dark regime of 14:10 hours) the successive formation of the photosynthetic apparatus during cell ontogeny is correlated with large changes in photosynthetic efficiency (P Brandt, B von Kessel 1983 Plant Physiol 72: 616-619; B Kohnke, P Brandt 1984 Biochim Biophys Acta 766: 156-16... |
Serine hydroxymethyltransferase has been purified 1,550-fold from the plant fraction of soybean (Glycine max [L]. Merr. cv Williams) nodules. The pH optimum for the enzyme was at 8.5. The native molecular weight was 230,000 with a subunit molecular weight of 55,000 which suggested a tetramer of identical subunits. The ... |
Two methods were developed for the detection of altered ureide metabolism in legume nodules. Both techniques are based on the positive correlation between the presence of high xanthine dehydrogenase (EC 1.2.1.37) specific activity in nodules and the ability of those nodules to produce the ureides, allantoin and allanto... |
The localizations of soybean lectin (SBL) and antigenically related proteins in cotyledons and roots of lectin positive (Le(+)) and lectin negative (Le(-)) soybean cultivars were compared by light level immunocytochemistry using antibodies produced against the 120 kilodalton (kD) native seed lectin tetramer or its subu... |
Inorganic phosphate (Pi) inhibits threonine synthase of Lemna, and cystathionine gamma-synthase less strongly. AMP is an extremely potent and structurally specific inhibitor of threonine synthase. Each inhibition progressively decreases with increasing concentrations of O-phosphohomoserine (OPH). To study the in vivo e... |
In fully expanded leaves of greenhouse-grown cotton (Gossypium hirsutum L., cv Coker 100) plants, carbon export, starch accumulation rate, and carbon exchange rate exhibited different behavior during the light period. Starch accumulation rates were relatively constant during the light period, whereas carbon export rate... |
The effects of added NAD on substrate oxidation by turnip (Brassica rapa L.) and beetroot (Beta vulgaris L.) mitochondria were investigated. State 3 malate and 2-oxoglutarate oxidation rates with turnip mitochondria were stimulated 25 to 40% by external NAD. Following NAD-depletion this stimulation by NAD was increased... |
Two nitrate reductase (NR) mutants were selected for low nitrate reductase (LNR) activity by in vivo NR microassays of M(2) seedlings derived from nitrosomethylurea-mutagenized soybean (Glycine max [L.] Merr. cv Williams) seeds. The mutants (LNR-5 and LNR-6) appeared to have normal nitrate-inducible NR activity. Both m... |
Antibodies to broad bean polyphenoloxidase (PPO) were used to detect and demonstrate that the PPOs found in several different plants have many similarities in common. Crude extracts from leaves of broad bean, bush bean, lettuce, mung bean, pea, soybean, spinach, tobacco, and tomato contained enzyme which cross-reacted ... |
Root cultures of various solanaceous plants grow well in vitro and produce large amounts of tropane alkaloids. Enzyme activity that converts hyoscyamine to 6beta-hydroxyhyoscyamine is present in cell-free extracts from cultured roots of Hyoscyamus niger L. The enzyme hyoscyamine 6beta-hydroxylase was purified 3.3-fold ... |
To widen the selection of proteins for gene expression studies in barley seeds, experiments were performed to identify proteins whose synthesis is differentially regulated in developing and germinating seed tissues. The in vitro synthesis of nine distinct barley proteins was compared using mRNAs from isolated endosperm... |
Since 1-(malonylamino)cyclopropane-1-carboxylic acid (MACC), the major conjugate of 1-aminocyclopropane-1-carboxylic acid (ACC) in plant tissues, is a poor ethylene producer, it is generally thought that MACC is a biologically inactive end product of ACC. In the present study we have shown that the capability of waterc... |
Western blots of soluble protein from wheat, rice, and corn showed that ADPglucose pyrophosphorylase subunits have a size of 50 kilodaltons from endosperm tissue and 43 and 46 kilodaltons from leaf. Antisera to ADPglucose pyrophosphorylase precipitated in vitro translation products of 73 and 76 kilodaltons when leaf po... |
Labeling patterns from (14)CO(2) pulses to leaves and whole leaf metabolite contents were examined during photosynthetic induction in Flaveria trinervia, a C(4) dicot of the NADP-malic enzyme subgroup. During the first one to two minutes of illumination, malate was the primary initial product of (14)CO(2) assimiltion (... |
We have recently reported that the activity of maize leaf glycerate kinase [EC 2.7.1.31] is regulated in vivo by the light/dark transition, possibly involving the ferredoxin/thioredoxin mechanism, and that the stimulating effect of light can be mimicked in vitro by incubation of crude leaf extract with reducing compoun... |
Illumination of previously darkened maize (Zea mays L. cv Golden Cross Bantam T51) leaves had no effect on the concentration of phosphoenolpyruvate (PEP) carboxylase protein, but increased enzyme activity about 2-fold when assayed under suboptimal conditions (pH 7.0 and limiting PEP). In addition, sensitivity to effect... |
The metabolism of fixed (14)CO(2) and the utilization of the C-4 carboxyl of malate and aspartate were examined during photosynthetic induction in Flaveria trinervia, a C(4) dicot of the NADP-malic enzyme subgroup. Pulse/chase experiments indicated that both malate and aspartate appeared to function directly in the C(4... |
The tissue and subcellular distribution of prephenate aminotransferase, an enzyme of the shikimate pathway, was investigated in protoplasts from leaves of Sorghum bicolor. Activity was detected in purified epidermal and mesophyll protoplasts, and in bundle sheath strands. After fractionation of mesophyll and epidermal ... |
When the glutelin protein fraction of rice (Oryza sativa L.) seeds was fractionated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, three size classes of proteins, 51 kilodaltons (kD), 34 to 37 kD, and 21 to 22 kD, as well as a contaminating prolamine polypeptide of 14 kD were detected. Antibodies were ra... |
A cDNA clone for the glyoxysomal enzyme malate synthase was isolated from a cDNA library made with polyadenylated RNA from the cotyledons of germinating Cucumis sativus L. This cloned DNA sequence was used as a probe to characterize changes in the amounts of malate synthase gene transcripts in cotyledons of cucumber se... |
The accumulation of arginine in leaves of four citrus rootstock cultivars during P deficiency has been demonstrated to be due to increased de novo synthesis rather than decreased catabolism or increased protein degradation (E Rabe, CJ Lovatt, 1984, Plant Physiol 76: 747-752). In this report, we provide evidence (a) tha... |
A plasma membrane-enriched fraction prepared from barley roots was analyzed by two-dimensional gel electrophoresis. Four methods of sample solubilization were assessed on silver stained gels. When membranes were solubilized with 2% sodium dodecyl sulfate followed by addition of Nonidet P-40, gels had high background st... |
The leucine specific serine proteinase present in the soluble fraction of leaves from Spinacia oleracea L. (called Leu-proteinase) has been purified by acetone precipitation and a combination of gel-filtration, ion exchange, and adsorption chromatography. This enzyme shows a molecular weight of 60,000 +/- 3,000 daltons... |
Intact leucoplasts from the endosperm of developing castor oil seed were isolated by Percoll density gradient centrifugation. The precursor to the small subunit of ribulose 1,5-bisphosphate carboxylase from pea was synthesized in vitro from hybrid-selected mRNA. Leucoplasts imported this precursor by an ATP-requiring m... |
Extracts of resting and germinating (3 days at 20 degrees C) wheat (Triticum aestivum L. cv Ruso) grains rapidly hydrolyzed various benzyloxycarbonyldipeptides (Z-dipeptides) at pH 4 to 6. Similar activities were present in extracts of mature flag leaves. Fractionation by chromatography on CM-cellulose and on Sephadex ... |
Iron deficiency in higher plants causes accumulation of salts of organic acids in the roots, the most characteristic being citrate. We show that citrate and malate accumulate in beans (Phaseolus vulgaris L. var Prélude), not because of a lack of the iron-containing enzyme aconitase (EC 4.2.1.3), but in close coupling t... |
The biosynthesis and processing of cellulase from ripening avocado fruit was studied. The mature protein is a glycoprotein, as judged by concanavalin A binding, with a molecular weight of 54,200. Upon complete deglycosylation by treatment with trifluoromethane sulfonic acid the mature protein has a molecular weight of ... |
Leaf tissue of a mutant of Arabidopsis thaliana contains reduced levels of both 16:3 and 18:3 fatty acids and has correspondingly increased levels of the 16:2 and 18:2 precursors due to a single recessive nuclear mutation. The kinetics of in vivo labeling of lipids with [(14)C]acetate and quantitative analysis of the f... |
Cd-binding protein was extracted from tomato roots and purified on QAE-Sephadex A-25 and on Sephadex G-75 in 1 molar KCl buffer. The protein preparation was light brown and contained predominantly Cd and small amounts of Zn and Cu. Polyacrylamide gel electrophoresis at pH 6.9 removed the brown material from protein whi... |
The development of Brassica napus L. cv Tower embryos of different ages cultured in vitro with and without high osmoticum (0.48 and 0.69 molar sorbitol) was compared with normal development in situ to investigate the role of a drying environment in embryo maturation. Sensitivity to osmoticum was assayed in terms of its... |
We have developed procedures for detection and characterization of UDP-glucose: glucosyltransferases following electrophoretic separation in nondenaturing polyacrylamide gels. Using digitonin-solubilized membrane protein preparations from a variety of plants and two cellulose-producing bacteria, activity can be demonst... |
Macerase, a pectinase-containing enzyme mixture, was used to digest cell walls isolated from cultured pear cells. Following digestion, the reaction mixture was boiled to inactivate enzymes. Addition of soluble aliquots of the mixture to suspension cultures of pear cells led to a rapid and transient production of ethyle... |
Enzymes of sucrose degradation and glycolysis in cultured sycamore (Acer pseudoplatanus L.) cells were assayed and characterized in crude extracts and after partial purification, in an attempt to identify pathways for sucrose catabolism. Desalted cell extracts contained similar activities (20-40 nanomoles per milligram... |
We have examined the time course for accumulation of each of 12 different nuclear gene transcripts in pea buds after irradiating dark grown seedlings with a single pulse low fluence red light (10(3) micromoles per square meter delivered in 100 seconds). The 12 time courses can be grouped into four general classes. Six ... |
The mechanisms and the controlling factors of malate oxidation by mitochondria from leaves of Kalanchoë blossfeldiana Poelln. plants performing Crassulacean acid metabolism were investigated using Percollpurified mitochondria. The effects of pH and of various cofactors (ATP, NAD(+), coenzyme A) on malate dehydrogenase ... |
The presence of betaine, a quaternary ammonium compound, at a concentration (0.5 molar) reported to accumulate inside Aphanothece halophytica in response to increasing external salinity, slightly promoted ribulose-1,5-bisphosphate (RuBP) carboxylase activity. KCl at 0.25 molar inhibited RuBP carboxylase about 55%. Beta... |
Membrane vesicles were isolated from the roots of the halophyte Atriplex nummularia Lindl. H(+)-translocating Mg(2+)-ATPase activity was manifested by the establishment of a positive membrane potential (measured as SCN(-) accumulation); and also by the establishment of a transmembrane pH gradient (measured by quinacrin... |
alpha-Amylase is one of the major enzymes present in the seeds of both Araucaria species of South America and it initiates starch hydrolysis during germination and early seedling growth. The pattern of the multiple forms of alpha-amylase of the two Araucaria species was investigated by electrophoresis and isoelectrofoc... |
The proton-translocating, plasma membrane ATPase was purified from tomato roots. At the final stage of purification approximately 80% of the protein was found in a single band with an apparent molecular weight of 90 kilodaltons. Cross-linking studies indicated that the ATPase normally exists as a trimer of catalytic su... |
The N-acetylglucosamine (GlcNAc) transferase that catalyzes the formation of dolichyl-pyrophosphoryl-GlcNAc-GlcNAc from UDP-GlcNAc and dolichyl-pyrophosphoryl-GlcNAc was solubilized from the microsomal enzyme fraction of mung beans with 1.5% Triton X-100, and was purified 140-fold on columns of DE-52 and hydroxylapatit... |
Mitochondria were isolated from nodules of cowpea (Vigna unguiculata (L). Walp.) and purified on a Percoll gradient. They were only slightly contaminated by bacteroids (an average of 3.5%), and had low lipoxygenase activity. Compared to mitochondria from hypocotyls the nodule mitochondria had similar O(2) uptake rates ... |
Adenylate kinase (EC 2.7.4.3) from leaves of maize (Zea mays) was purified to homogeneity using (NH(4))(2)SO(4) fractionation, followed by chromatography on DEAE-cellulose, hydroxyapatite, Sephadex G-75SF, and Green A dye-ligand columns. The purified enzyme had specific activity of about 1,550 micromoles ADP produced p... |
To investigate possible charge and size heterogeneity of catalase (EC 1.11.1.6) in cotton (Gossypium hirsutum L. cv Deltapine 62), extracts of cotyledons from different developmental ages were subjected to nondenaturing polyacrylamide gel electrophoresis and isoelectric focusing. Special precautions (e.g. fresh homogen... |
Recent studies have provided a fairly detailed view of the various intermediates involved in the reactions of ribulosebisphosphate carboxylase and the manner in which the catalytically essential metal atom might catalyze their interconversions. A better understanding of how the enzyme distinguishes between its alternat... |
In addition to chlorophyll-protein complexes, other proteins were labeled when isolated developing pea (Pisum sativum L.) chloroplasts were incubated with [(14)C]-5-aminolevulinic acid. The major labeled band (M(r) = 43 kilodaltons by lithium dodecyl sulfate-polyacrylamide gel electrophoresis) was labeled even in the p... |
The heme and chlorophyll precursor delta-aminolevulinic acid (ALA) can be formed by two biosynthetic routes: from the intact carbon skeleton of glutamate via a five-carbon pathway, which occurs in chloroplasts and bluegreen algae, and by ALA synthase-catalyzed condensation of succinyl-CoA and glycine, which occurs in b... |
Photosystem II particles of Chlamydomonas reinhardtii contain three extrinsic polypeptides of 29, 20, and 16 kilodaltons, whose functions are incompletely defined. We prepared a monospecific polyclonal antibody against the 29 kilodalton protein and determined that it also specifically recognizes a protein of approximat... |
A purified pectate lyase isozyme derived from Erwinia chrysanthemi induced rapid net K(+) efflux and H(+) influx in suspension-cultured tobacco cells. Comparable fluxes of other ions (Na(+), Cl(-)) were not observed. The K(+) efflux/H(+) influx response began within 15 minutes after addition of enzyme to cell suspensio... |
Zein, the major storage protein of maize (Zea mays L.) endosperm, was extracted from a number of inbreds with alcohol plus a reducing agent. Isoelectric focusing (IEF) separated total zeins into 41 components, while sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) separated total zeins into about 15... |
Cell-free extracts capable of converting [(14)C]-labeled gibberellins (GAs) were prepared from spinach (Spinacia oleracea L.) leaves. [(14)C]-labeled GAs, prepared enzymically from [(14)C]mevalonic acid, were incubated with these extracts, and products were identified by gas chromatography-mass spectrometry. The follow... |
Two isozymes of 3-deoxy-d-arabino-heptulosonate 7-phosphate (DAHP) synthase, denoted DS-Mn and DS-Co, were identified following DEAE-cellulose chromatography of crude extracts prepared from suspension-cultured cells of Nicotiana silvestris. The strikingly different properties of the isozymes allowed the development of ... |
Photosynthetic characteristics were studied in several F(1) hybrids between C(4) and C(3)-C(4) species of Flaveria. Stable carbon isotope ratios, O(2) inhibition of apparent photosynthesis, and phosphoenolpyruvate carboxylase activities in the hybrids were similar to the means for the parents. Values of CO(2) compensat... |
Inactivation of the water splitting enzyme complex in leaves or isolated chloroplasts results in increased susceptibility of photosystem II (PSII) to damage by light. Photoinhibition under this condition occurs in very weak light. The site of damage is exclusive of the water splitting complex yet still on the oxidizing... |
As part of a continuing effort to elucidate the mode of action of abscisic acid (ABA) in barley (Hordeum vulgare L. cv Himalaya) aleurone layers, we have investigated the induction of several polypeptides by ABA in this tissue. There were nine ABA-induced polypeptides as observed by one-dimensional sodium dodecyl sulfa... |
The developmental accumulation pattern of messenger RNA transcripts and polypeptides for wheat gliadins and ADPglucose pyrophosphorylase was determined using cDNA and antibody probes. Gliadin mRNA was detected on Northern and RNA dot blots at 3 days after flowering, it increased 100-fold by 10 days and decreased subseq... |
Ca(2+) uptake into microsomal vesicles was measured using the fluorescent probe chlorotetracycline. The Ca(2+) uptake was ATP-dependent and did not occur in the presence of the calcium ionophore A23187. There was a linear relationship between the rate of ATP-dependent fluorescence increase using chlorotetracycline and ... |
The photoreversible nature of the regulation of nitrate reductase is one of the most interesting features of this enzyme. As well as other chemicals, NH(2)OH reversibly inactivates the reduced form of nitrate reductase from Ankistrodesmus braunii. From the partial activities of the enzyme, only terminal nitrate reducta... |
The activities of 10 enzymes involved in carbohydrate metabolism were measured in both desiccated and rehydrated fronds of the desiccation-tolerant pteridophyte Selaginella lepidophylla (Hook. & Grev.) Spring. Enzyme conservation was defined as the ratio of desiccated to hydrated frond enzyme activity. The mean level o... |
Past research on kernel growth in wheat (Triticum aestivum) has shown that the kernel itself largely regulates the influx of sucrose for consequent starch synthesis in the endosperm of the grain. The first step in the conversion of sucrose to starch is catalyzed by sucrose synthase (EC 2.4.13). Sucrose synthase activit... |
The effects of pH on catalysis and activation characteristics of spinach ribulose 1,5-bisphosphate (RuBP) carboxylase were examined at air level of CO(2). Catalysis at limiting CO(2) was independent of pH over the range of pH 8.2 to 8.8 However, the kinetics of activation and the apparent equilibrium between the activa... |
First leaves and flag leaves of the wheat species Triticum aestivum cv Anza (6x), T. boeoticum Boiss (2x) L. were examined for content of pyruvate, orthophosphate dikinase (PPDK), phosphoenolpyruvate carboxylase (PEPC), and ribulose 1,5-bisphosphate carboxylase (RuBPC) by protein blot analyses using antibodies to maize... |
The contents of (+)-cis-abscisic acid (ABA) and alkaline-hydrolyzable ABA-conjugate(s) were analyzed by means of enzyme immunoassay in partially purified extracts of developing and mature sweet orange fruit (Citrus sinensis [L.] Osbeck cv Washington navel). A relatively small increase in ABA was observed in the fruit e... |
Physiological and biochemical markers of metabolic competence were assayed in bacteroids isolated from root nodules of control, dark-stressed, and recovered plants of Glycine max Merr. cv ;Woodworth.' Nitrogenase-dependent acetylene reduction by the whole plant decreased to 8% of control rates after 4 days of dark stre... |
Starch granules isolated from potato (Solanum tuberosum L.) tubers were extracted with sodium dodecyl sulfate and the extract was analyzed. A major protein with a molecular weight of 60,000 daltons was detected. This protein was purified by preparative sodium dodecyl sulfate-gel electrophoresis and specific antibodies ... |
Cellulose was produced heterotrophically from different carbon substrates by carrot tissue cultures and Acetobacter xylinum (a cellulose-producing bacterium) and by castor bean seeds germinated in the dark, in each case in the presence of water having known concentration of oxygen-18 ((18)O). We used the relationship b... |
Two forms of spinach acyl carrier protein (ACP-I and ACP-II) have recently been characterized and found to be expressed in a tissue-specific manner (JB Ohlrogge, TM Kuo, 1985 J Biol Chem 260: 8032). To examine possible different functions for these ACP isoforms, we have tested purified preparations of spinach leaf ACP-... |
Two enzymes capable of hydrolyzing fructose-1,6-bisphosphate (FBP) have been isolated from the foliose lichen Peltigera rufescens (Weis) Mudd. These enzymes can be separated using Sephadex G-100 and DEAE Sephacel chromatography. One enzyme has a pH optimum of 6.5, and a substrate affinity of 228 micromolar FBP. This en... |
The kinetic parameters of the photosynthetic fructose-1,6-bisphosphatase isolated from Peltigera rufescens (Weis) Mudd. were measured on a seasonal basis and during a laboratory-induced temperature acclimation. Both the substrate affinity and Ea changed on a seasonal basis. During the summer, the Ea decreased from 91.8... |
Photosynthetic CO(2)-fixation in isolated pea (Pisum sativum L., cv Little Marvel) chloroplasts during induction is markedly inhibited by 0.4 millimolar sulfite. Sulfate at the same concentration has almost no effect. The (14)CO(2)-fixation pattern indicates that the primary effect of sulfite is inhibition of the react... |
Thylakoid membrane preparations obtained from mechanically disrupted (sonicated) cells of the cyanobacterium Anabaena sp. strain 7119 show a membrane-bound ferredoxin-NADP(+) oxidoreductase (EC 1.18.1.2) as determined either by specific antibodies or by using the ferredoxin-dependent NADPH-cytochrome c reductase activi... |
Initial observations showed a 100% increase in H(2)-uptake (Hup) activity of Rhizobium leguminosarum strain 3855 in pea root nodules (Pisum sativum L. cv Alaska) on plants growing in a baked clay substrate relative to those growing in vermiculite, and an investigation of nutrient factors responsible for the phenomenon ... |
The phosphoenolpyruvate carboxylase of Amaranthus paniculatus shows in vitro optimum affinity (S(0.5)) to phosphoenolpyruvate at a relatively high temperature (about 35 degrees C); even in the presence of activators, it functions efficiently only above 25 to 27 degrees C. At lower temperatures, a steep increase of acti... |
3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the key regulatory enzyme of the isoprenoid pathway, was found to be predominantly microsomal in Ochromonas malhamensis, a chrysophytic alga. Detection of HMG-CoA reductase requires the presence of 1% bovine serum albumin during cell homogenization, and the act... |
Water hyacinth (Eichhornia crassipes [Mart.] Solms) plants were grown in environmental chambers at ambient and enriched CO(2) levels (330 and 600 microliters CO(2) per liter). Daughter plants (ramets) produced in the enriched CO(2) gained 39% greater dry weight than those at ambient CO(2), but the original mother plant... |
Salinity (100 millimolar NaCl) was found to reduce photosynthetic capacity independent of stomatal closure in Phaseolus vulgaris. This reduction was shown to be a consequence of a reduction in the efficiency of ribulose-1,5-bisphosphate (RuBP) carboxylase (RuBPCase) rather than a reduction in the leaf content of photos... |
Phosphoenolpyruvate carboxylase (PEPC) was extracted from maize (Zea mays L. cv Golden Cross Bantam T51) leaves harvested in the dark or light and was partially purified by (NH(4))(2)SO(4) fractionation and gel filtration to yield preparations that were 80% homogeneous. Malate sensitivity, PEPC activity, and PEPC prote... |
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