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In response to adaptation to NaCl, cultured tobacco cells (Nicotiana tabacum L. cv Wisconsin 38) synthesize a major 26 kilodalton protein which has been named osmotin due to its induction by low water potentials. To help characterize the expression of osmotin in adapted cells, a cDNA clone for osmotin has been isolated... |
The effect of nitrate application on glutamine synthetase activity in roots of pea (Pisum sativum L.) seedlings (2 weeks old) was studied. Separation of organelles from root fragments by sucrose density-gradient centrifugation revealed that both nitrite reductase and glutamine synthetase activities increased in root pl... |
A mutant of Arabidopsis thaliana, deficient in activity of the chloroplast n-6 desaturase, accumulated high levels of C(16:1) and C(18:1) lipids and had correspondingly reduced levels of polyunsaturated lipids. The altered lipid composition of the mutant had pronounced effects on chloroplast ultrastructure, thylakoid m... |
Expression of the gene coding for nitrite reductase (NiR) is induced upon the addition of nitrate. We have analyzed this induction process in hydroponically grown maize (Zea mays L.) seedlings where the level of nitrate in the medium can be easily manipulated. There is a rapid induction of NiR mRNA upon addition of nit... |
Carbon oxysulfide (carbonyl sulfide, COS) is a close structural analog of CO(2). Although hydrolysis of COS (to CO(2) and H(2)S) does occur at alkaline pH (>9), at pH 8.0 the rate of hydrolysis is slow enough to allow investigation of COS as a possible substrate and inhibitor of the active CO(2) transport system of Syn... |
cDNA clones were selected from a corn (Zea mays L.) leaf lambda gt11 expression library using polyclonal antibodies for corn leaf NADH:nitrate reductase. One clone, Zmnrl, had a 2.1 kilobase insert, which hybridized to a 3.2 kilobase mRNA. The deduced amino acid sequence of Zmnrl was nearly identical to peptide sequenc... |
To determine if medium and long chain fatty acids can be appropriately metabolized by species that normally produce 16 and 18 carbon fatty acids, homogenates of developing Cuphea wrightii, Carthamus tinctorius, and Crambe abyssinica seeds were incubated with radiolabeled lauric, palmitic, oleic, and erucic acids. In al... |
In barley (Hordeum vulgare L.), alcohol dehydrogenase (ADH) and lactate dehydrogenase (LDH) are induced by anaerobiosis in both aleurone layers and roots. Under aerobic conditions, developing seeds of cv Himalaya accumulate ADH activity, which survives seed drying and rehydration. This activity consists almost entirely... |
As part of the study of the possible role(s) of CBF-1, a cytokinin-binding protein abundant in wheat embryo, a cytokinin oxidase was found in wheat (Triticum aestivum L.) germ and partially purified by conventional purification techniques and high performance chromatofocusing. This preparation catalyzes conversion of N... |
The rate of CO(2) fixation by ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) following addition of ribulose 1,5-bisphosphate (RuBP) to fully activated enzyme, declined with first-order kinetics, resulting in 50% loss of rubisco activity after 10 to 12 minutes. This in vitro decline in rubisco activity, terme... |
Vegetative fronds of Spirodela polyrrhiza were induced to form dormant turions by the addition of 1 micromolar abscisic acid or by shading. The cell wall polymers of fronds contained a high proportion of the branched-chain pentose, d-apiose (about 20% of total noncellulosic wall sugar residues), whereas turion cell wal... |
Three distinct flavonol-specific sulfotransferases were partially purified from the shoot tips of Flaveria chloraefolia A. Gray by fractional precipitation with ammonium sulfate, followed by gel filtration on Sephacryl S-200, 3'-phosphoadenosine 5-phosphate-Agarose affinity chromatography and chromatofocusing on Mono P... |
The sucrose-stimulated in vivo hydrolysis of indole-3-acetyl-l-alanine (IAAIa) in tobacco (Nicotiana tabacum L.) leaf discs was confirmed by in vitro analysis of an IAAIa-hydrolyzing enzyme isolated from the same tissue. The enzymic activity could be stimulated by either aging of the tissue or by application of externa... |
A temporary vegetative storage protein, composed of similar 25 kilodalton and 27 kilodalton subunits, was found to be abundant in soybean (Glycine max (L.) Herr. var Hobbit) leaves, stems, pods, flower petals, germinated cotyledons, and less abundant in roots, nodules and seeds. Total pod protein was highest at 3 weeks... |
Gametophytes of the fern Onoclea sensibilis grow as filaments in the dark and in red light and become planar in blue light. Pulse-labeling 4-day-old gametophytes with [(35)S]methionine at different times after transfer to dark, red, and blue light environments revealed higher rates of amino acid uptake and protein synt... |
When Brassica nigra leaf petiole suspension cells were subjected to 7 days of inorganic phosphate (Pi) starvation the extractable activity of: (a) pyrophosphate:fructose 6-phosphate 1-phosphotransferase, nonphosphorylating NADP-glyceraldehyde 3-phosphate dehydrogenase, phosphoenolpyruvate phosphatase, and phosphoenolpy... |
Plasma membrane vesicles from pea (Pisum sativum L.) seedlings contain an autophosphorylating calcium-activated protein kinase of relative molecular weight 18,000 (phosphoprotein 18, pp 18). Pulse chase analysis revealed that pp 18 autophosphorylation exhibited very rapid turnover. pp 18 was the only detectable plasma ... |
We have compared the activity of 5-aminolevulinate dehydratase (5-ALAD) with the amount of protein detected by specific antibodies in rocket immunoelectrophoresis. Parallel kinetic evolutions of enzymic activity and amount of antigen were observed in radish (Raphanus sativus L.) cotyledons, both in complete darkness or... |
Alanine aminotransferase, otherwise called glutamate-pyruvate aminotransferase (GPT), activity increases up to fourfold during several days of anaerobic induction in barley (Hordeum vulgare L.) roots, reaching a maximum activity of 13 international units per gram fresh weight. This increase in activity paralleled the i... |
An enzyme catalyzing the formation of O-glucosylzeatin in immature embryos of Phaseolus lunatus was purified 2500-fold using ammonium sulfate precipitation followed by affinity and anion exchange chromatography. The enzyme uses trans-zeatin as substrate (K(m) 28 micromolar) but not cis-zeatin, ribosylzeatin, or dihydro... |
Antiserum was raised against the Avena sativa L. caryopsis beta-d-glucan fraction with an average molecular weight of 1.5 x 10(4). Polyclonal antibodies recovered from the serum after Protein A-Sepharose column chromatography precipitated when cross-reacted with high molecular weight (1-->3), (1-->4)-beta-d-glucans. Th... |
We have examined post-transcriptional control of expression of the anaerobically induced sucrose synthase 1 (SS1) isozyme mRNA encoded by the shrunken (Sh) gene of maize (Zea mays L.). The SS1 transcript level is increased in maize seedling roots during anaerobiosis without a concomitant increase in the SS1 protein lev... |
Levels of several polypeptides in addition to the vegetative storage protein (VSP) increase in soybean leaves following depodding. Two of these polypeptides interact specifically with antibodies raised against the seed lectins of Phaseolus vulgaris and soybean. The two polypeptides, which had apparent molecular masses ... |
Juice tissues of citrus lack phloem; therefore, photosynthates enroute to juice sacs exit the vascular system on the surface of each segment. Areas of extensive phloem unloading and transport (vascular bundles + segment epidermis) can thus be separated from those of assimilate storage (juice sacs) and adjacent tissues ... |
A cDNA clone for phenylalanine ammonia-lyase (PAL) induced in wounded sweet potato (Ipomoea batatas Lam.) root was obtained by immunoscreening a cDNA library. The protein produced in Escherichia coli cells containing the plasmid pPAL02 was indistinguishable from sweet potato PAL as judged by Ouchterlony double diffusio... |
In microsomes from 24-hour-old radish (Raphanus sativus L.) seedlings ATP-dependent Ca(2+) uptake occurs only in inside-out plasma membrane vesicles (F Rasi-Caldogno, MC Pugliarello, MI De Michelis [1987] Plant Physiol 83: 994-1000). A Ca(2+)-dependent ATPase activity can be shown in the same microsomes, when assays ar... |
If green light-acclimated Fremyella diplosiphon cultures are transferred to red light, the transcription from the inducible phycocyanin gene set increases at least 30-fold within 60 minutes. This effect is inhibited completely by the protein synthesis inhibitors chloramphenicol and spectinomycin. Application of chloram... |
Cytosolic ATP-dependent phosphofructokinase (PFK) from spinach leaves (Spinacia oleracea L.) was enriched 2600-fold by (NH(4))(2)SO(4) fractionation, DEAE anion exchange chromatography, Blue Sepharose CL-6B, and ATP agarose type 3-affinity chromatography. The final preparation had a specific activity of 417 nkat per mi... |
The influence of plasma membrane lipid components on the activity of the H(+)-ATPase has been studied by determining the effect of surfactants on membrane lipids and ATPase activity of oat (Avena sativa L.) root plasma membrane vesicles purified by a two-phase partitioning procedure. Triton X-100, at 25 to 1 (weight/we... |
Transfer of C(4) photosynthetic traits was studied through hybridization of Flaveria trinervia (Spreng.) Mohr (C(4)) and Flaveria brownii A.M. Powell (C(4)-like) with Flaveria linearis Lag. (C(3)-C(4)) and the C(3) species Flaveria pringlei Gandoger (C(3)). Fertility was low, based on irregular chromosome pairing and l... |
The uptake of acidic and basic sugar derivatives in Lemna gibba L. was studied. Uronic acids applied to the experimental solution (50 millimolar) induced a small decrease of the membrane potential (10 +/- 1 millivolt galacturonic acid, and 20 +/- 4 millivolt glucuronic acid). After incubation of the plants in a 0.1 mil... |
Diacylglycerol kinase (ATP:1,2-diacylglycerol 3-phosphotransferase, EC 2.7.1.107) from suspension-cultured Catharanthus roseus cells was extracted from a membrane fraction with 0.6% Triton X-100 and 150 millimolar NaCl and was purified about 900-fold by DEAE-cellulose, blue Sepharose, gel permeation, and phenyl-Sepharo... |
The cyanogenic glucoside dhurrin is rapidly synthesized in etiolated seedlings of Sorghum bicolor (L.) Moench. The dhurrin content of the seedlings increases sigmoidally with the germination time. Shoots of 10 centimeters height contain 850 nanomoles of dhurrin per shoot corresponding to 6% of the dry weight. The biosy... |
The variations of the amounts of phospholipid transfer proteins (PLTP), determined by ELISA and immunoblotting methods, were followed during the maturation and germination of maize (Zea mays L.) seeds. Changes of the amounts of PLTP occur during seed maturation. The levels of PLTP, low in the first 3 weeks after fecond... |
Carbamoyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), and aspartate transcarbamylase (ATC) were assayed in extracts from unpollinated ovaries of Pisum sativum L. CPS and OTC activities were, per milligram protein, the highest reported in a plant tissue, representing an estimated 0.1% of the protein in... |
A sensitive and specific method was developed for assay of aspartokinase (EC 2.7.2.4) in crude extracts of Lemna paucicostata. Lysine inhibited approximately 93%, and threonine approximately 6%; together, these amino acids inhibited 99%. Inhibition by lysine was synergistically increased by S-adenosylmethionine, which ... |
Comprehensive studies were made with Lemna paucicostata Hegelm. 6746 of the effects of combinations of lysine, methionine, and threonine on growth rates, soluble amino acid contents, aspartokinase activities, and fluxes of 4-carbon moieties from aspartate through the aspartokinase step into the amino acids of the aspar... |
Phase shifts of the circadian rhythm of K(+) uptake by Lemna gibba G3, caused by pulse administration of various amino acids analogs, were examined and compared. The various phase shifts were not due to any disturbance in the biosynthesis of amino acids, since the effective time of day and direction of the phase shift ... |
Three endopeptidases (EP2, EP3, and EP4) were identified after fractionation of pea (Pisum sativum, var Feltham First) chloroplast stromal extracts. All three were identified by their ability to cleave in vitro-synthesized preplastocyanin to lower molecular weight forms. EP2 is inhibited by phenylmethylsulfonylfluoride... |
A reductase catalyzing the conversion of zeatin to dihydrozeatin was detected in soluble fractions of immature Phaseolus vulgaris embryos. The enzyme was partially purified by ammonium sulfate fractionation and affinity, gel filtration, and anion exchange chromatography. NADPH was the only cofactor required for enzyme ... |
Aspartate aminotransferase (l-aspartate:2-oxoglutarate aminotransferase, EC 2.6.1.1 [AAT]), a key enzyme in the assimilation of C and N compounds, was purified from the cytosol of alfalfa (Medicago sativa L.) root nodules. Isoforms that increased during nodule development, AAT-2a, AAT-2b, and AAT-2c, were purified grea... |
The substrate requirement of the H(+)-ATPase in purified corn root tonoplast vesicles was investigated. The coupled activities, ATP hydrolysis and proton pumping, were simultaneously supported only by Mg(2+) or Mn(2+). The presence of Ca(2+) or Ba(2+) did not significantly affect the coupled activities. The addition of... |
The properties of enzymes involved in ethylene biosynthesis are reviewed and progress toward the purification of these enzymes is described. The enzyme whose activity usually limits ethylene biosynthesis is 1-aminocyclopropane-1-carboxylate (ACC) synthase. Even though its level in plants is extremely low, it has now be... |
The subtilisin inhibitor (MBSI-A) from the mung bean (Vigna radiata (L.) Wilczek) seed has been purified to homogeneity. MBSI-A consists of a single polypeptide chain of 119 residues, with a high content of glutamic acid/glutamine, aspartic acid/asparagine, valine, threonine, and proline (19, 12, 10, 9, and 8 residue p... |
Citrus exocortis viroid induces in tomato plants (Lycopersicon esculentum) synthesis and accumulation of a pathogenesis-related protein (P69) previously reported to be a proteinase (Vera P, Conejero V [1988] Plant Physiol 87: 58-63). By immunogold/transmission electron microscopy, we have studied the distribution of th... |
The chiA gene of Serratia marcescens codes for a secreted protein, bacterial chitinase (ChiA). We have investigated the modifications and the cellular location of ChiA when it is expressed in transgenic tobacco plants. Immunoblots on total leaf protein probed with antibody to ChiA showed that when the bacterial chitina... |
Pea (Pisum sativum L.) chloroplast D-enzyme (4-alpha-d-glucanotransferase, EC 2.4. 1.25) was purified greater than 750-fold and partially characterized. It is a dimer with a subunit M(r) of ca. 50,000. Optimal activity is between pH 7.5 and 8.0 with maltotriose as substrate and the enzyme's K(m) for maltotriose is 3.3 ... |
Tracerkinetic experiments were performed using l-[guanidino-(14)C]arginine, l-[U-(14)C]arginine, l-[ureido-(14)C]citrulline, and l-[1-(14)C]ornithine to investigate arginine utilization in developing cotyledons of Glycine max (L.) Merrill. Excised cotyledons were injected with carrier-free (14)C compounds and incubated... |
Phosphate starvation increased the secretion of at least six proteins by suspension cultured tomato (Lycopersicon esculentum L. and L. pennellii) cells. Cells exhibited a biphasic response to phosphate (Pi) starvation. The early phase involved enhanced secretion of three proteins in response to transfer to a Pi-deplete... |
Growth potential of potato (Solanum tuberosum L.) plants is influenced by seed-tuber age. After 24 days of growth, single-eye seedcores from 7-month-old seed-tubers produced 64% more foliar dry matter than those from 19-month-old seed-tubers, reflecting a higher growth rate. This study was initiated to determine if dif... |
The effect of gibberellic acid (GA) on light-induced greening of etiolated pea plants (Pisum sativum [L.] cultivars Alaska and Progress) was characterized. Progress, a GA-deficient dwarf of Alaska, was found to accumulate chlorophyll and light harvesting chlorophyll protein associated with photosystem II (LHC-II) more ... |
Calcium ionophoresis into coenocytic cells of Neurospora crassa activates the plasma membrane proton pump as measured by current-voltage analysis. This is direct evidence that intracellular calcium regulates the activity of a key transport enzyme found in higher plants and fungi. |
The subcellular localization of ADPglucose pyrophosphorylase, a key regulatory enzyme in starch biosynthesis, was determined in developing potato tuber cells by immunocytochemical localization techniques at the light microscopy level. Specific labeling of ADPglucose pyrophosphorylase by either immunofluorescence or imm... |
Etiolated hypocotyls of the resistant soybean (Glycine max [L.] Merr.) cultivar Harosoy 63 became susceptible to Phytophthora megasperma (Drechs.) f.sp. glycinea (Hildeb.) Kuan and Erwin race 1 after treatment with abscisic acid. Susceptibility was expressed by increases in lesion size and a major decrease in accumulat... |
A phosphorescent trivalent cation, terbium [Tb(III)], has been used to study the binding of different polyvalent cations to the proteins of wheat (Triticum aestivum L.) root plasma membranes. The phosphorescence emission intensity of Tb(III) was enhanced after Tb(III) binding to wheat root plasma membranes as a result ... |
Structural features of feruloylated arabinoxylan (feraxan) present in Zea mays L. (hybrid B 73 x Mo 17) coleoptile cell walls have been studied using a purified feraxan-dissociating enzyme (feraxanase) and an alpha-arabinofuranosidase. This experimental approach has demonstrated the following. (a) Feraxanase dissociate... |
Developmental patterns of alpha-amylase in Vigna radiata cotyledons during and following germination were quite different depending on the differences in the treatments of cotyledons during the imbibitional stage. When axis-detached cotyledons were imbibed in water with seed-coats attached, alpha-amylase activity did n... |
Plants of Zea mays L. cv TX5855 were grown in a complete, well oxygenated nutrient solution then subjected to nutrient starvation by omitting either nitrate and ammonium or phosphate from the solution. These treatments induced the formation of aerenchyma close to the apex of the adventitious roots that subsequently eme... |
A library of monoclonal antibodies directed against the proteins of the inner mitochondrial membrane was screened for antibodies that could bind to the glutamate/aspartate transporter of pea mitochondria and thereby inhibit its activity. One antibody, 2C7, had the property of inhibiting glutamate and aspartate-dependen... |
At least two hydroxypyruvate reductases (HPRs), differing in specificity for NAD(P)H and (presumably) utilizing glyoxylate as a secondary substrate, were identified by fractionation of crude maize leaf extracts with ammonium sulfate. The NADH-preferring enzyme, which most probably represented peroxisomal HPR, was preci... |
Nitrate reductase (NR, EC 1.6.6.1) from higher plants is a homodimeric enzyme carrying a molybdenum cofactor at the catalytic site. Tungsten can be substituted for molybdenum in the cofactor structure, resulting in an inactive enzyme. When nitratefed Nicotiana tabacum plants were grown on a nutrient solution in which t... |
Two isoforms of dihydroxyacetone phosphate reductase were present in Dunaliella tertiolecta. The major form was located in the chloroplast and the minor form in the cytosol. The chloroplastic reductase eluted first from a DEAE cellulose column followed immediately by the cytosolic form. Both forms were unstable and col... |
A lipoxygenase preparation was obtained from green algae Oscillatoria sp. and was shown to differ from previous described lipoxygenases in the positional specificity and pH characteristics of the dioxygenation reaction. The enzyme had a pH optimum at 8.8 and was inactive at pH 6. Oscillatoria lipoxygenase converted lin... |
The consequences of light adaptation and acclimation of photosynthesis on photosynthetic nitrogen use efficiency (NUE), particularly as it relates to the efficiency of ribulose-1,5-bisphosphate carboxylase (Rubisco) use in photosynthetic CO(2) assimilation, was studied in the sun species Glycine max and the shade speci... |
The water-insoluble 1,4-beta-linked products formed from UDP-[(14)C]glucose by pea membranes were dissolved in hot dimethyl-sulfoxide/paraformaldehyde and fractionated on columns of controlled pore glass beads calibrated with dextran standards. The products eluted with a peak size close to 70 kilodaltons in dextran equ... |
The active transport of CO(2) in the cyanobacterium Synechococcus UTEX 625 was inhibited by H(2)S. Treatment of the cells with up to 150 micromolar H(2)S + HS(-) at pH 8.0 had little effect on Na(+)-dependent HCO(3) (-) transport or photosynthetic O(2) evolution, but CO(2) transport was inhibited by more than 90%. CO(2... |
A mutant of barley (Hordeum vulgare L.), LaPr 88/29, deficient in NADH-dependent hydroxypyruvate reductase (HPR) activity has been isolated. The activities of both NADH (5%) and NADPH-dependent (19%) HPR were severely reduced in this mutant compared to the wild type. Although lacking an enzyme in the main carbon pathwa... |
Cells of tobacco (Nicotiana tabacum L.) adapted to grow in severe osmotic stress of 428 millimolar NaCl (-23 bar) or 30% polyethylene glycol 8000 (-28 bar) exhibit a drastically altered growth physiology that results in slower cell expansion and fully expanded cells with volumes only one-fifth to one-eighth those of un... |
An endogenous alpha-amylase inhibitor was found to be synthesized in embryos of developing barley grain (Hordeum vulgare cv Bonanza). Accumulation of this protein occurred late in development (stage IV), at the same time that endogenous abscisic acid (ABA) showed a large increase. The inhibitor could be induced up to 2... |
Pyrophosphate:fructose-6-phosphate phosphotransferase (PFP, EC 2.7.1.90) from endosperm of developing wheat (Triticum aestivum L.) grains was purified to apparent homogeneity with about 52% recovery using ammonium sulfate fractionation, ion exchange chromatography on DEAE-cellulose and gel filtration through Sepharose-... |
The effect of ozone (O(3)) on ribulose bisphosphate carboxylase/oxygenase (Rubisco) activity and quantity and net photosynthesis in greenhouse-grown Solanum tuberosum L. cv ;Norland' foliage was studied in relation to oxidant-induced premature senescence. Plants, 26 days old, were exposed to 0.06 to 0.08 microliters pe... |
Photosystem I (PSI) has been isolated from mesophyll chloroplasts of mature maize leaves. The isolated PSI (PSI-200) was used as starting material for preparing an antenna-depleted core (PSI-100). Both of these preparations appear to be quite analogous to PSI complexes isolated from other plant tissue sources, such as ... |
The chemical composition of extracellular polymers released by cells of tobacco (Nicotiana tabacum L. cv W38) adapted to a medium containing 30% polyethylene glycol 8000 (-28 bar) or 428 millimolar NaCl (-23 bar) was compared to the composition of those released by unadapted cells. Unadapted cells released uronic acid-... |
l-Tryptophan decarboxylase (TDC) (EC 4.2.1.27) enzyme activity was induced in cell suspension cultures of Catharanthus roseus after treatment with a Pythium aphanidermatum elicitor preparation. The enzyme was extracted from lyophilized cells containing high levels of TDC and the protein was purified to homogeneity. The... |
Synechocystis (PCC 6714) is photoinhibited at low photon flux density when illuminated in medium devoid of Na(+). Photosynthetic activity and variable fluorescence yield were measured in intact cells during the course of inhibition and during recovery from inhibition in order to characterize sequential inhibitory event... |
The effect of inorganic phosphate (Pi) on sucrose-phosphate synthase (SPS) activity was determined for the enzyme from five plant species (Nicotiana tabacum L., Spinacia oleracea L., Triticum aestivum L., Zea mays L., Glycine max L.) using two assay methods. The assay method based on determination of uridine diphosphat... |
Wheat germ agglutinin (WGA) is synthesized as a proprotein with a glycosylated, 15 amino acid, carboxyl-terminal propeptide. This glycopeptide is cleaved from pro-WGA to produce the mature lectin during the transport of WGA to the protein bodies/vacuoles. To study the posttranslational modification of WGA, it would be ... |
Polyphenoloxidase was purified from broad bean (Vicia faba) leaves. The purified enzyme contained two immunocross-reactive proteins of approximately 60 to 65 and 43 to 45 kilodaltons. Further electrophoretic separation resolved these proteins into doublets with molecular mass of 61.5, 60, 44.5, and 43 kilodaltons, resp... |
Active human carbonic anhydrase II (HCAII) protein was expressed in the cyanobacterium Synechococcus PCC7942 by means of transformation with the bidirectional expression vector, pCA. This expression was driven by the bacterial Tac promoter and was regulated by the IacIQ repressor protein, which was expressed from the s... |
Five- and six-subunit forms of F(1)-ATPase were purified from pea (Pisum sativum L. cv Homesteader) cotyledon submitochondrial particles. Apart from the usual complement of five subunits, the six-subunit enzyme contained an additional 26,500-dalton protein. Both forms of the F(1)-ATPase were used to reconstitute oxidat... |
The isoflavonoid phytoalexin pisatin is synthesized by Pisum sativum in response to microbial infection and certain other forms of stress. An enzyme which synthesizes pisatin by methylating the 3-hydroxyl of (+)6a-hydroxymaackiain (HMK) was extracted from CuCl(2)-stressed pea seedlings. The enzyme was enriched 370-fold... |
The phospholipid dependence of the UDP-glucose sterol glucosyl transferase (UDPG-SGTase) from maize coleoptiles was previously demonstrated using the partially purified and highly delipidated enzyme, in the presence of the detergent Triton X-100 (P Ullmann, P Bouvier-Navé, P Benveniste [1987] Plant Physiol 85: 51-55). ... |
Transcription rates and mRNA levels for Brassica napus seed storage protein families, cruciferin and napin, have been determined in embryos developing in the seed, as well as in embryos cultured with and without abscisic acid. Cruciferin and napin mRNAs are high during the cell expansion phase of embryo development, re... |
Expression of three chloroplast genes encoding proteins of different chloroplast complexes and the rRNA gene has been examined in cells having reduced numbers of chloroplast genomes as a result of growth in the presence of the thymidine analog 5-fluorodeoxyuridine. While accumulation of total mRNA for rpl2 (ribosomal p... |
It is not known why some species accumulate high concentrations of sucrose in leaves during photosynthesis while others do not. To determine the possible basis, we have studied 10 species, known to differ in the accumulation of sucrose, in terms of activities of sucrose hydrolyzing enzymes. In general, acid invertase a... |
During seed development, various storage proteins and hydrolases accumulate in specialized storage vacuoles, the protein bodies, via an elaborate intracellular transport system involving the rough endoplasmic reticulum, the Golgi apparatus, and transit vesicles. Clathrin-coated vesicles, similar to those which transpor... |
An efficient and largely genotype-independent transformation method for Brassica napus and Brassica oleracea was established based on neo or bar as selectable marker genes. Hypocotyl explants of Brassica napus and Brassica oleracea cultivars were infected with Agrobacterium strains containing chimeric neo and bar genes... |
ATP-dependent polycation-stimulated phosphorylation of highly purified phytochrome preparations from etiolated Avena seedlings has been reported previously (Y-S Wong, H-C Cheng, DA Walsh, JC Lagarias [1986] J Biol Chem 261: 12089-12097). In this study, we present a more detailed description of the properties of this pr... |
We have isolated the membranes of the protein storage vacuoles (protein bodies) from Phaseolus vulgaris cotyledons and purified an integral membrane protein with M(r) 25,000 (TP 25). Antiserum to TP 25 recognizes an abundant polypeptide in the total cell extracts of many different seeds (monocots, dicots, and a gymnosp... |
Plasma membranes isolated from three-day-old maize (Zea mays L.) roots by aqueous two-phase partitioning were used as starting material for the purification of a novel electron transport enzyme. The detergent-solubilized enzyme was purified by dyeligand affinity chromatography on Cibacron blue 3G-A-agarose. Elution was... |
The pyridoxal phosphate-dependent 1-aminocyclopropane-1-carboxylate (ACC) synthase catalyzes the conversion of S-adenosyl-l-methionine (AdoMet) to ACC, and is inactivated by AdoMet during the reaction. l-Vinylglycine was found to be a competitive inhibitor of the enzyme, and to cause a time-dependent inactivation of th... |
The initial kinetics of accumulation of chlorophylls (Chl) were analyzed during optimal greening of Chlamydomonas reinhardtii y-1 at 38 degrees C. Acetate was required for maximal synthesis of Chl, which occurred at a linear rate when degreened cells were exposed to light. During the first hour Chl a and b accumulated ... |
Photosynthetic rates, chlorophyll content, and activities of several photosynthetic enzymes were determined per cell, per unit DNA, and per unit leaf area in five ploidal levels of the C(4) dicot Atriplex confertifolia. Volumes of bundle sheath and mesophyll protoplasts were measured in enzymatic digestions of leaf tis... |
The relationship between tubulin gene expression and cell elongation was explored in developing internodes of Glycine max (L.) Merr., using light as a variable to alter the rate of elongation. First internodes of etiolated seedlings elongated two to three times more rapidly than did those of seedlings growing under a 1... |
Dihydrofolate reductase (DHFR) and thymidylate synthase (TS) activities are associated with a 285,000 molecular weight enzyme complex in carrot (Daucus carota L.). Selection for methotrexate (MTX) resistance by stepwise increase of the concentration of MTX results in a high frequency adaptation to MTX with little or no... |
The transfer of genetic material into soybean tissue was accomplished by using an avirulent strain of Agrobacterium tumefaciens which contained the binary vector pGA482. The method used for transformation requires no tissue culture steps as it involves the inoculation of the plumule, cotyledonary node, and adjacent cot... |
NaCl and KCl enhanced the degradation of chlorophylls and proteins in detached rice (Oryza sativa) leaves in a concentration-dependent manner. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) accounted for 73 to 80% of the protein lost by day 4 in the light. NaCl at 50 millimolar increased proteolysis by 21% o... |
The influence of various colors of soil cover (mulch) on the farred/red (FR/R) ratio in upwardly reflected light and on concentrations of chlorophyll (Chl) and light-harvesting Chl protein (LHC-II) were measured under field conditions. The FR/R ratios above green surfaces were higher than over white surfaces. Even thou... |
Separation of catalase isozymes from leaf extracts of three diverse plant species (Nicotiana sylvestris, Zea mays, Hordeum vulgare L.) revealed a distinct isozyme with enhanced peroxidatic activity (30-, 70-, 28-fold over typical catalase, respectively) which constituted 10 to 20% of the total catalase activity. In mai... |
Certain N-substituted phthalimides (NSPs) have gibberellin (GA)-like activity in a number of GA bioassays. The interaction between representative NSPs and a protein fraction from cucumber (Cucumis sativus L.) hypocotyls that has GA-binding characteristics consistent with those expected of GA receptors was studied. Anal... |
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