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l-Tyrosine decarboxylase (EC 4.1.1.25) activity was induced in cell suspension cultures of Thalictrum rugosum Ait. and Eschscholtzia californica Cham. with a yeast polysaccharide preparation (elicitor). The highest l-tyrosine decarboxylase activity in extracts from 7-day-old cell cultures of E. californica was observed... |
Properties of purified l-tyrosine decarboxylase (EC 4.1.1.25) from elicitor-induced cell suspension cultures of Eschscholtzia californica Cham. and Thalictrum rugosum Ait. are described. l-Tyrosine decarboxylase is a dimeric enzyme with a molecular weight of 112,600 +/- 600 daltons. The isoelectric point was estimated ... |
Primary cell walls, free from cytoplasmic contamination were prepared from corn (Zea mays L.) roots and potato (Solanum tuberosum) tubers. After EDTA treatment, the bound acid phosphatase activities were measured in the presence of various multivalent cations. Under the conditions of minimized Donnan effect and at pH 4... |
A comparison of two phosphoryl enzyme reaction states associated with the plasma membrane ATPase of red beet (Beta vulgaris L.) storage tissue was carried out to determine if their differences in reactivity toward ADP and K(+) was related to a structural difference in the site of phosphorylation. Using a pulse labeling... |
The reaction mechanism of the solubilized red beet (Beta vulgaris L.) plasma membrane ATPase was studied with a rapid quenching apparatus. Using a dual-labeled substrate ([gamma-(32)P]ATP and [5',8-(3)H]ATP), the presteady-state time course of phosphoenzyme formation, phosphate liberation and ADP liberation was examine... |
In etiolated squash (Cucurbita maxima L.) cotyledons, nitrate-inducible NADH:nitrate reductase activity and protein were increased in darkness by red light pulses with red/far-red photoreversibility. Continuous far-red light also led to increased levels of nitrate reductase activity and protein. Poly(A)+RNA, which hybr... |
We have examined the activity of the thiamin phosphate pyrophosphorylase in Arabidopsis thaliana wild type and in a mutant (th-1) which requires exogenous thiamin for growth. Mutant and wild-type plants grown in 1 x 10(-7) molar thiamin were used for the examination of the production of thiamin and thiamin monophosphat... |
Microsomal membrane vesicles isolated from the petals of young carnation (Dianthus caryophyllus L. cv White Sim) flowers accumulate Ca(2+) in the presence of ATP. The specific activity of ATP-dependent uptake is approximately 20 nanomoles per milligram of protein per 30 minutes. The membranes also hydrolyze ATP, but Ca... |
Mitochondria isolated from potato (Solanum tuberosum L.) tuber were investigated for the presence of a nicotinamide nucleotide transhydrogenase activity. Submitochondrial particles derived from these mitochondria by sonication catalyzed a reduction of NAD(+) or 3-acetylpyridine-NAD(+) by NADPH, which showed a maximum o... |
The activities of three enzymes and the concentration of intermediates involved in the synthesis of N,N-dimethyltryptamine (DMT) from endogenous tryptophan (TRP) have been measured in vitro in seedlings of Phalaris aquatica L. cv Australian Commercial over 16 days after planting. The activities of tryptophan decarboxyl... |
Changes occurring in several chloroplast components during Norflurazon-induced photobleaching of Pisum sativum seedlings were investigated. mRNA steady state levels of the chlorophyll a/b-binding protein of photosystem II, ferredoxin I, the small and large subunits of ribulose 1,5-bisphosphate carboxylase, and pEA214 a... |
Photosynthetic CO(2) assimilation, transpiration, ribulose-1,5-bisphosphate carboxylase (RuBPCase), and soluble protein were reduced in leaves of water-deficit (stress) ;Valencia' orange (Citrus sinensis [L.] Osbeck). Maximum photosynthetic CO(2) assimilation and transpiration, which occurred before midday for both con... |
The influence of light-dark cycles and nitrate supply on nitrate reductase (NR) mRNA levels was studied in two plant species, tobacco (Nicotiana tabacum) and tomato (Lycopersicon esculentum) using specific NR DNA probes. In the same series of experiments, changes in the levels of NR protein (NRP) by enzyme-linked immun... |
A two-step purification protocol was used in an attempt to separate the constitutive NAD(P)H-nitrate reductase [NAD(P)H-NR, pH 6.5; EC 1.6.6.2] activity from the nitric oxide and nitrogen dioxide (NO((x))) evolution activity extracted from soybean (Glycine max [L.] Merr.) leaflets. Both of these activities were eluted ... |
The lipase from Rhizopus arrhizus and the lipolytic acyl hydrolase from potato tubers have been used to determine the transmembrane distribution of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) in prothylakoids and thylakoids from oat (Avena sativa). Both galactolipids were found to be asymm... |
The low protein barley (Hordeum vulgare L.) cultivar ;Karl' is deficient in hordeins, the major storage protein fraction, but has normal levels of other endosperm protein fractions. We compared hordein gene expression in Karl with that in ;Traill,' a related cultivar that contains normal amounts of hordein. In plants g... |
Impaired chloroplast function is responsible for nearly two-thirds of the inhibition of net photosynthesis caused by dark chilling in tomato (Lycopersicon esculentum Mill.). Yet the plant can eventually recover full photosynthetic capacity if it is rewarmed in darkness at high relative humidity. As a means of identifyi... |
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) rapidly extracted from leaves of wheat (Triticum aestivum) and purified activated RuBPCO were incubated in the presence and absence of 20 millimolar HCO(3) (-) and changes in activation state were followed. Rapid inactivation occurred in the presence, but not in ... |
HCN is the putative product of C-1 and amino moieties of 1-aminocyclopropane-1-carboxylic acid (ACC) during its conversion to ethylene. In apple (Malus sylvestrus Mill.) slices or auxin-treated mungbean (Vigna radiata L.) hypocotyls, which produced ethylene at high rates, the steady state concentration of HCN was found... |
Several lines of evidence with intact tissues suggest amino acid transport is mediated by a proton-amino acid symport (L Rheinhold, A Kaplan 1984 Annu Rev Plant Physiol 35: 45-83). However, biochemical studies of proton-coupled amino acid transport in isolated membrane vesicles have not been reported. In the experiment... |
When the unicellular green alga Chlamydomonas reinhardtii is placed under low CO(2) conditions it adapts by making an inorganic carbon accumulating mechanism. Algal cells were labeled with (35)SO(4) (-2) during this adaptation period and labeled proteins specific for this low CO(2) adaptation were identified. Four majo... |
Antibodies cross-reactive with specific membrane proteins were used to investigate membrane development in Anacystis nidulans R2 during recovery from iron stress. Polyclonal antibodies prepared using the iron-regulated chlorophyll (Chl)-protein CPVI-4 (HB Pakrasi, HC Riethman, LA Sherman 1985 Proc Natl Acad Sci USA 82:... |
Antibodies were raised against individual polypeptides of the oxygen-evolving photosystem II (PSII) complex from mesophyll chloroplasts of Vicia faba (Long Pod). These antibodies were used to probe immunologically for the presence of the main structural components of the PSII complex in guard cell chloroplasts, using b... |
Activities and subunit levels of three C(4) enzymes were determined for F(1) hybrids between C(4) and C(3)-C(4)Flaveria species. For phosphoenolpyruvate carboxylase and pyruvate orthophosphate, dikinase, enzyme amounts in the hybrids were close to the mid-parent means. However, activity and subunit levels of NADP-malic... |
1-Aminocyclopropane-1-carboxylic acid (ACC) is aerobically oxidized in plant tissues to form ethylene by ethylene-forming enzyme (EFE). The effect of substrate (ACC and oxygen) concentrations on ethylene production rate by plant tissues was investigated. The K(m) value for O(2) in ethylene production varied greatly dep... |
We have earlier identified a set of proteins of 23 to 25 kilodaltons (kD), covering an isoelectric point (pI) range of 6.2 to 8.2, which accumulate gradually during normal embryogenesis of Zea mays and disappear in early germination. These polypeptides can be induced prematurely in immature embryos by abscisic acid (AB... |
The expression of alpha-amylase isozymes in barley (Hordeum vulgare L.) aleurone layers is known to be maximally induced between 12 and 20 hours after addition of the phytohormone, gibberellic acid (GA(3)). Addition of another hormone, abscisic acid (ABA), or its metabolite, phaseic acid, during this time period result... |
Cultured tobacco cells (Nicotiana tabacum L. var Wisconsin-38) developed tolerance to otherwise nonpermissive 54 degrees C treatment when heat-shocked at 38 degrees C (2 h) but not at 42 degrees C. Heat-shocked cells (38 degrees C) exhibited little normal growth when the 54 degrees C stress came immediately after heat ... |
The succulent leaf of the obligate Crassulacean acid metabolism plant Crassula falcata comprises two distinct types of parenchyma. The peripheral tissue is dark green, whereas the central tissue is relatively colorless. We have investigated whether the conventional interpretation of Crassulacean acid metabolism-simply,... |
Ascorbate oxidase from pumpkin (Cucurbita sp.) was purified from a commercially available preparation. A single polypeptide band with M(r) 64,000 was detected after sodium dodecylsulfate-polyacrylamide gel electrophoresis of the purified enzyme. In double immunodiffusion tests, antiserum against the purified preparatio... |
By screening two rice (Oryza sativa L.) seed cDNA libraries, recombinant cDNA clones encoding the rice prolamine seed storage protein were isolated. Based on cross-hybridization and restriction enzyme map analyses, these clones can be divided into two homology classes. All clones contain a single open reading frame enc... |
A membrane-bound auxin-binding protein (MABP) was solubilized by Triton X-100 from cell suspension cultures of Nicotiana tabacum L. Solubilization of MABP was dependent on the detergent concentration and more than 80% of naphthalene-1-acetic acid (NAA)-binding activity was recovered by an optimum concentration of 0.2%.... |
The long-term effects of altered salinities on the physiology of the intertidal red alga Gelidium coulteri Harv. were assessed. Plants were transfered from 30 grams per liter salinity to media with salinities from 0 to 50 grams per liter. Growth rate, agar, photosynthesis, respiration, and various metabolites were quan... |
Chenopods synthesize betaine by a two-step oxidation of choline: choline --> betaine aldehyde --> betaine. The pathway is chloroplastic; the first step has been shown in isolated spinach (Spinacia oleracea L.) chloroplasts to be O(2)- and light-dependent, the role of light being to provide reducing power (P Weigel, EA ... |
A small basic peptide with an unusual amino acid composition has been isolated from the seeds of pumpkin, Cucurbita maxima. Amino acid analysis and sequence data show the protein to be about 36 residues in length, with an approximate composition Lys(1), Arg(14), Asp(3), (Glu + Gln)(15), Gly(1), Pro(1), Trp(1). On the b... |
Ethylene production rates and tissue ethylene concentrations were determined for the single-gene, Epinastic (Epi) tomato (Lycopersicon esculentum Mill.) mutant, and its parent, cv VFN8. The Epi phenotype was characterized by severe leaf epinasty, thickened stems and petioles, and a compact growth habit. In 4-day-old se... |
A mutant (NS 458) of Nicotiana sylvestris (Spegazzini and Comes) unable to synthesize leaf starch was isolated in the M(2) generation following ethyl methanesulfonate mutagenesis by testing with iodine. Segregation ratios in reciprocal F(2) progenies showed that the starchless phenotype resulted from a recessive mutati... |
The levels of a membrane-bound auxin binding protein (MABP) and a root-specific peroxidase (RSP) were studied in several tobacco (Nicotiana tabacum L.) cell lines including an auxin-resistant variant. Groups of cell lines were distinguished which behaved differentially with respect to MABP and RSP depending on the horm... |
The universal tetrapyrrole precursor delta-aminolevulinic acid (ALA) is formed from glutamate (Glu) in algae and higher plants. In the postulated reaction sequence, Glu-tRNA is produced by a Glu-tRNA synthetase, and the product serves as a substrate for a reduction step catalyzed by a pyridine nucleotide-requiring Glu-... |
A dihydroxyacetone phosphate (DHAP) reductase has been isolated in 50% yield from Dunaliella tertiolecta by rapid chromatography on diethylaminoethyl cellulose. The activity was located in the chloroplasts. The enzyme was cold labile, but if stored with 2 molar glycerol, most of the activity was restored at 30 degrees ... |
Only one form of membrane-associated cellulase was found previously in the lower petiolar pulvinus of Phaseolus vulgaris (cv Red Kidney). The cellulase has an isoelectric point (pI) of 4.5 (DE Koehler, LN Lewis 1979 Plant Physiol 63: 677-679). This enzyme was detected in abscission zones collected before the onset of a... |
Photosynthetic energy conversion was investigated in five species of marine unicellular algae, (Dunaliella tertiolecta, Thalassiosira pseudonana, T. weisflogii, Skeletorema costatum, Isochrysis galbana) representing three phylogenetic classes, which were grown under steady state conditions with either light or inorgani... |
Chitinase and beta-1,3-glucanase purified from pea pods acted synergistically in the degradation of fungal cell walls. The antifungal potential of the two enzymes was studied directly by adding protein preparations to paper discs placed on agar plates containing germinated fungal spores. Protein extracts from pea pods ... |
Glutamine synthetase was localized in leaves and cotyledons of young tomato (Lycopersicon esculentum Mill.) plants using immunogold techniques coupled to transmission electron microscopy. The enzyme occurs only in chloroplasts and is most probably a stroma constituent. |
The specific activities of nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase, and glutamate dehydrogenase were determined in intact protoplasts and intact chloroplasts from Chlamydomonas reinhardtii. After correction for contamination, the data were used to calculate the portion of each enz... |
Pulses of a fluorinated analog of leucine, 5',5',5'-trifluoroleucine, reset the phase of the circadian rhythm of K(+) uptake in Lemna gibba G3 under continuous light conditions. The trifluoroleucine pulse caused the largest delay phase-shifts during the early subjective phase but it caused only small phase advances. Th... |
Transcriptional fusions composed of a 19 kilodalton zein cDNA, the 5' flanking region from a beta-phaseolin gene, and 3' flanking regions from either the phaseolin or a 15-kilodalton zein gene were introduced into Petunia by Agrobacterium-mediated transformation. The expression of both zein mRNA and protein in these tr... |
Ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) activase protein was purified from spinach leaves by ammonium sulfate precipitation and ion exchange fast protein liquid chromatography. This resulted in 48-fold purification with 70% recovery of activity and yielded up to 18 milligrams of rubisco activase prote... |
The requirements for reactivation (dephosphorylation) of the pea (Pisum sativum L.) leaf mitochondrial pyruvate dehydrogenase complex (PDC) were studied in terms of magnesium and ATP effects with intact and permeabilized mitochondria. The requirement for high concentrations of magnesium for reactivation previously repo... |
Corn seedlings (Zea mays cv W64A x W182E) were grown hydroponically, in the presence or absence of NO(3) (-), with or without light and with NH(4)Cl as the only N source. In agreement with earlier results nitrate reductase (NR) activity was found only in plants treated with both light and NO(3) (-). Sodium dodecyl sulf... |
Calcium transport into tomato (Lycopersicon esculentum Mill, cv Castlemart) fruit tonoplast vesicles was studied. Calcium uptake was stimulated approximately 10-fold by MgATP. Two ATP-dependent Ca(2+) transport activities could be resolved on the basis of sensitivity to nitrate and affinity for Ca(2+). A low affinity C... |
The steady state level of mRNA for the light-harvesting chlorophyll a/b binding protein (LHCP) varies considerably during a day-night light cycle in expanding leaves of tobacco (Nicotiana tabacum, cv Wisconsin 38). The maximum (day) level is at least one hundred-fold higher than the minimum (night) level. The oscillati... |
Wheat (Triticum aestivum L. cv Albis) was grown in open-top chambers in the field and fumigated daily with charcoal-filtered air (0.015 microliters per liter O(3)), nonfiltered air (0.03 microliters per liter O(3)), and air enriched with either 0.07 or 0.10 microliters per liter ozone (seasonal 8 hour/day [9 am-5 pm] m... |
The growth of the halotolerant cyanobacterium Aphanothece halophytica, previously adapted to 0.5 molar NaCl, was optimal when NaCl concentration in culture medium was in the range 0.5 to 1.0 molar. The growth was delayed at either too low or too high salinities with lag time of ca. 0.5 day in 0.25 molar NaCl and ca. 2 ... |
The precursor to the light-harvesting chlorophyll a/b protein of photosystem II can insert into isolated thylakoid membranes if reaction mixtures also contain ATP and a soluble extract of chloroplasts. Optimization of this insertion process and the initial characterization of the soluble chloroplastic component are pre... |
The proteinaceous noncompetitive inhibitor of starch phosphorylase isolated from the root of sweet potato (Ipomoea batatas [L.] Lam.) (TC Chang, JC Su 1986 Plant Physiol 80: 534-538) has been identified as a beta-amylase. The starch phosphorylase inhibitor and beta-amylase activities copurified to give a protein indist... |
A light microsomal membrane fraction (collected on 28% weight/volume sucrose) from young mycelia of Phycomyces blakesleeanus Bgff. stationary cultures exhibited Mg(2+) ATP-dependent proton pumping as monitored with the dye neutral red or by accumulation of [(14)C]methylamine. The substrate kinetics for ATP (K(m(ATP)) 1... |
Protoplasts purified from pea (Pisum sativum L.) leaves were lysed and fractionated to assess the subcellular distribution of NADPH-dependent hydroxypyruvate reductase (NADPH-HPR) activity. Rate-zonal centrifugation and sucrose-gradient experiments demonstrated that most (about 70%) of the NADPH-HPR activity was locate... |
A native PSI complex and a PSI core complex have been isolated from the halophilic green alga, Dunaliella salina. The composition and properties of these complexes are similar to previously described PSI complexes from spinach membranes. By growth on (14)C-NaHCO(3), it has been possible to isolate uniformly labeled (14... |
The intraorganellar distribution of superoxide dismutase (SOD) (EC 1.15.1.1) in two types of plant peroxisomes (glyoxysomes and leaf peroxisomes) was studied by determinations of SOD latency in intact organelles and by solubilization assays with 0.2 molar KCl. Glyoxysomes were purified from watermelon (Citrullus vulgar... |
The accumulation of radiolabeled plastid-encoded chlorophyll a-apoproteins is light dependent and is controlled at a posttranscriptional level. Illumination of dark-grown barley (Hordeum vulgare L.) with a brief pulse of red light induced the accumulation of radiolabeled chlorophyll a-apoproteins in subsequent protein ... |
Addition of elicitor, cell wall fragments of the fungus Phytophthora parasitica, to tobacco cell suspension cultures (Nicotiana tabacum) resulted in the rapid synthesis and secretion of large amounts of antibiotic sesquiterpenoids. Pulse-labeling experiments with [(14)C]acetate and [(3)H] mevalonate demonstrated that t... |
Growth at an elevated CO(2) concentration resulted in an enhanced capacity for soybean (Glycine max L. Merr. cv Bragg) leaflet photosynthesis. Plants were grown from seed in outdoor controlled-environment chambers under natural solar irradiance. Photosynthetic rates, measured during the seed filling stage, were up to 1... |
Among several wheat (Triticum aestivum L.) germ proteins able to lyse Micrococcus lysodeikticus, one lysozyme (W1A) was purified by ion-exchange chromatography, gel filtration, and preparative polyacrylamide gel electrophoresis. Polyclonal antibodies against this lysozyme were raised in rabbits. The in situ localizatio... |
Mature maize leaf tissue (Zea mays L.) was immunolabeled using a pre-embedding protocol with specific antibodies for nitrate reductase and protein A-colloidal gold. Immunogold label was found exclusively in the cytoplasm of mesophyll cells; no reaction was detected in bundle sheath cells. Chloroplasts, which were slice... |
Gibberellins A(12) (GA(12)), GA(53), GA(44), GA(19), GA(17), GA(20), GA(29), GA(1), and GA(8) have been identified from extracts of vegetative shoots of normal (wild type) maize using full scan capillary gas chromatography-mass spectrometry and Kovats retention indices. Seven of these gibberellins (GAs) have been quant... |
RNA is an essential component for the enzymic conversion of glutamate to delta-aminolevulinic acid (ALA), the universal heme and chlorophyll precursor, as carried out in plants, algae, and some bacteria. The RNA required in this process was reported to bear a close structural resemblance to tRNA(Glu(UUC)), and it can b... |
The response of pearl millet (Pennisetum glaucum [L.]) seedlings to prolonged starvation was investigated at the biochemical and ultrastructural level. After 2 days of darkness the bulk of the seedling carbohydrate reserves were depleted. After 8 days in the dark the respiratory rate had declined to less than 50% of it... |
Plants cultivated with Cd can produce large amounts of phytochelatins. Since these compounds contain much cysteine, these plants should have an increased rate of assimilatory sulfate reduction, the biosynthetic pathway leading to cysteine. To test this prediction, the effect of Cd on growth, sulfate assimilation in viv... |
The photolyzable sucrose derivative 6'-deoxy-6'-(4-azido-2-hydroxy)-benzamidosucrose (6'-HABS), competitively inhibited the influx of [(14)C] sucrose into protoplasts from developing soybean (Glycine max L. Merr cv Wye) cotyledons. Photolysis of (125)I-labeled 6'-HABS in the presence of 10 millimolar dithiothreitol and... |
Changes in the levels of cytosolic and chloroplastic isoforms of glutamine synthetase were examined in senescing radish (Raphanus sativus L. cv Comet) cotyledons by immunoblotting analysis using antibodies raised separately against maize glutamine synthetase isoforms. Translatable mRNAs for these isoforms were also exa... |
A proteinase was purified from germinated barley (green malt from Hordeum vulgare L. cv Morex) by acidic extraction, ammonium sulfate fractionation and successive chromatographies on CM-cellulose, hemoglobin sepharose, Sephadex G-75 and organomercurial agarose columns. The overall purification and final recovery were 2... |
The response of maize (Zea mays L.) protoplasts to high temperature stress was investigated. After isolation and electroporation, protoplasts were preincubated for 12 hours at 26 degrees C then incubated for 6 hours at elevated temperatures. The pattern of polypeptides synthesized by these protoplasts during the last h... |
Phosphoenolpyruvate carboxylase isolated from maize (Zea mays L.) leaves was assayed with varying concentrations of free phosphoenolpyruvate at several fixed-varying concentrations of free magnesium higher than required to saturate the enzyme reaction. These assays produced velocity data which were found to form a fami... |
Na(+)/H(+) exchange activity in barley (Hordeum vulgare cv CM-72) root tonoplast was induced by Na(+) even in the presence of inhibitors of protein synthesis. Induction occurred with a half-time of only 15 minutes. When salt-treated roots were transferred to a nutrient solution containing no Na(+), the activity disappe... |
Cell-free translation of Chlamydomonas reinhardtii RNA in the presence of photosynthetic membranes resulted in association of the herbicide binding (Qb) protein with membranes. Incubation of recovered membranes with high salt did not extract the polypeptide from membranes. Tryptic digestion of in vivo labeled membranes... |
We previously reported (A Reinero, RN Beachy 1986 Plant Mol Biol 6:291-301) that coat protein (CP) of tobacco mosaic virus (TMV) accumulates in chloroplasts of systemically infected leaves. To determine the significance of such interaction we examined electron transport rates in chloroplasts containing different levels... |
Molecular cloning of polygalacturonase (PG; EC 3.2. 1.15) from fruits of tomato (Lycopersicon esculentum Mill cv Rutgers) was accomplished by constructing a cDNA library from turning stage poly(A)(+) RNA in lambdagtll and immunoscreening with polyclonal antibodies raised against purified PG2. Both PG cDNA and antibody ... |
The proteinaceous ethylene biosynthesis-inducing factor (EIF) that was purified from Cellulysin was also shown to contain a xylanase activity. In all nondenaturing protein separation methods employed (Sephacryl S-200 chromatography, and preparative isoelectric focusing and agarose electrophoresis), xylanase activity co... |
Protein kinase and phosphatase activities were studied in plasmalemma and tonoplast membrane fractions from corn (Zea mays L.) roots in order to test the hypothesis that the tonoplast H(+)-ATPase is regulated by intrinsic protein phosphorylation (G Zocchi, SA Rogers, JB Hanson 1983 Plant Sci Lett 31: 215-221), and to f... |
The light-dependent kinetics of the apparent in vivo synthesis and degradation of 2-carboxyarabinitol 1-phosphate (CA1P) were studied in three species of higher plants which differ in the extent to which this compound is involved in the light-dependent regulation of ribulose-1,5-bisphosphate carboxylase (Rubisco) activ... |
Chloroplast thylakoid protein phosphatase activity was measured using (32)P-labeled histone as an exogenous substrate and an assay of the (32)Pi released involving formation of a phosphomolybdate complex and organic extraction. The activity was liberated from wheat (Triticum aestivum) thylakoids by washing the membrane... |
The vacuolar pH and the trans-tonoplast DeltapH modifications induced by the activity of the two proton pumps H(+)-ATPase and H(+)-PPase and by the proton exchanges catalyzed by the Na(+)/H(+) and Ca(2+)/H(+) antiports at the tonoplast of isolated intact vacuoles prepared from Catharanthus roseus cells enriched in inor... |
A sulfhydryl-endopeptidase was purified as a 33 kilodalton (kD) mass polypeptide from cotyledons of Vigna mungo seedlings. Immunoblot analysis with antiserum made against the purified enzyme showed that the sulfhydryl-endopeptidase was synthesized only in the cotyledons during germination and that the amount of the enz... |
Most C(4) species are chilling sensitive and certain enzymes like pyruvate,Pi dikinase of the C(4) pathway are also cold labile. The ability of cations and compatible solutes to protect maize (Zea mays) dikinase against cold lability was examined. The enzyme in desalted extracts at pH 8 from preilluminated leaves could... |
Young or mature rosette leaves from spinach (Spinacia oleracea L.) plants growing in the field, in the greenhouse, or in a growth chamber under a regimen of 8 hours light and 16 hours dark contained 15 to 50 nanomoles per minute per gram wet weight of NADH:dihydroxyacetone phosphate reductase activity. Of this activity... |
Soybeans (Glycine max L.) accumulate a storage glycoprotein which is abundant in vegetative tissues, but is only a minor component of seeds. Changes in vegetative storage protein gene expression in leaves of control and depodded plants were monitored throughout plant development. Western and Northern blot hybridization... |
NAD malic enzyme (EC 1.1.1.39), which is involved in C(4) photosynthesis, was purified to electrophoretic homogeneity from leaves of Eleusine coracana and to near homogeneity from leaves of Panicum dichotomiflorum. The enzyme from each C(4) species was found to have only one type of subunit by SDS polyacrylamide gel el... |
Thermal acclimation by Saxifraga cernua to low temperatures results in a change in the optimum temperature for gross photosynthetic activity and may directly involve the photosynthetic apparatus. In order to test this hypothesis photosynthetic electron transport activity of S. cernua thylakoids acclimated to growth tem... |
This study employed in vitro seed culture to determine how C and N supply influence the growth (i.e. starch accumulation) and protein composition of maize (Zea mays L.) endosperm. Immature kernels were grown to maturity on liquid medium containing various concentrations of C (sucrose at 234 millimolar [low] and 468 mil... |
Malate synthase (EC 4.1.3.2) (MS), an enzyme unique to the glyoxylate cycle, was studied in cotyledons of dark-grown cotton (Gossypium hirsutum, L.) seedlings. MS has generally been regarded as a peripheral membrane protein in glyoxysomes and believed by some to be synthesized on rough ER. Immunocyto-chemical localizat... |
When Ribulose- 1,5-bisphosphate carboxylase/oxygenase was purified from spinach leaves (Spinacia oleracea) using precipitation with polyethylene glycol and MgCl(2) followed by DEAE cellulose chromatography, 75% of phosphoribulokinase and 7% of phosphoriboisomerase activities copurified with ribulose- 1,5-bisphosphate c... |
An enriched IgG serum fraction obtained from rabbits immunized against pea chloroplast fructose-1,6-bisphosphatase (FBPase) was used, coupled to colloidal gold (15 nanometer particles) goat anti-rabbit IgG, to analyze by electron microscopy the location of photosynthetic FBPase in pea (Pisum sativum L.) leaf ultrathin ... |
Intact cells and crude homogenates of high (1% CO(2)) and low dissolved inorganic carbon (C(i)) (30-50 microliters per liter of CO(2)) grown Synechococcus PCC7942 have carbonic anhydrase (CA)-like activity, which enables them to catalyze the exchange of (18)O from CO(2) to H(2)O. This activity was studied using a mass ... |
Diamine oxidase (DAO, EC 1.4.3.6) activity was examined in relation to polyamine content in Helianthus tuberosus L. during the first synchronous cell cycle induced in vitro by 2,4,-dichloro-phenoxyacetic acid in tuber slices and during the in vivo formation of the tuber. The optimal pH, buffer and dithiothreitol concen... |
The comparative analysis of plant hormones was undertaken on a 1-naphthaleneacetic acid tolerant mutant and normal tobacco (Nicotiana tabacum cv Xanthi) plantlets. The mutant plantlet was scrubby and impaired in its root morphogenesis. Degeneration of the root meristem was studied on tissue sections; it appeared very f... |
The aim of this study was to determine how Chondrus crispus, a marine red macroalga, acquires the inorganic carbon (C(i)) it utilizes for photosynthetic carbon fixation. Analyses of C(i) uptake were done using silicone oil centrifugation (using multicellular fragments of thallus), infrared gas analysis, and gas chromat... |
The vacuolar H(+)-ATPase of maize (Zea mays L.) root tip cells has been localized at the EM level using rabbit polyclonal antibodies to the 69 kilodalton subunit and protein A-colloidal gold. Intracellular gold particles were detected mainly on the tonoplast and Golgi membranes. Only about 27% of the vacuoles were labe... |
The inhibitory effects of the cyclic olefin 2,5-norbornadiene (NBD) on ethylene action were tested in carnation (Dianthus caryophyllus L. cv White Sim) flowers. Treatment of flowers at anthesis with ethylene in the presence of 500 microliters per liter NBD increased the concentration of ethylene required to elicit a re... |
Proton transport by the nitrate-insensitive, vanadate-sensitive ATPase in Kl-washed microsomes and reconstituted vesicles from maize (Zea mays L.) roots was followed by changes in acridine orange absorbance in the presence of either KNO(3) or KCl. Data from such studies obeyed a kinetic model in which net proton transp... |
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