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Resistance to the fungal plant pathogen Cochliobolus carbonum race 1 and to its host-selective toxin, HC-toxin, is determined by Hm, a single dominant gene in the host plant maize, (Zea mays L). Radiolabeled HC-toxin of specific activity 70 milliCuries per millimole, prepared by feeding tritiated d,l-alanine to the fun... |
A mutant of Arabidopsis thaliana deficient in the accumulation of inorganic phosphate has been isolated by screening directly for plants with altered quantities of total leaf phosphate. The mutant plants accumulate approximately 5% as much inorganic phosphate, and 24 to 44% as much total phosphate, as wild-type plants ... |
Wild-type Euglena gracillis cells synthesize the key chlorophyll precursor, delta-aminolevulinic acid (ALA), from glutamate in their plastids. The synthesis requires transfer RNA(Glu) (tRNA(Glu)) and the three enzymes, glutamyl-tRNA synthetase, glutamyl-tRNA reductase, and glutamate-1-semialdehyde aminotransferase. Non... |
The activation states of a number of chloroplastic enzymes of the photosynthetic carbon reduction cycle and levels of related metabolites were measured in leaves of sugar beet (Beta vulgaris L., Klein E-type multigerm) under slowly changing irradiance during a day. The activation states of both phosphoribulokinase and ... |
The effects of an electric current on ethylene biosynthesis were investigated in cucumber (Cucumis sativus L.) fruit that were producing almost no ethylene. Direct currents at 0.5 to 3.0 milliamperes induced much ethylene synthesis, with a rapid continuous increase in the rate, which reached a peak within 5 to 6 hours ... |
Ethylene biosynthesis-inducing xylanase (EIX) from the fungus Trichoderma viride elicits enhanced ethylene production and tissue necrosis in whole tobacco (Nicotiana tabacum cv Xanthi) plants at sites far removed from the point of EIX application when applied through a cut petiole. Symptoms develop in a specific patter... |
Protoplasts from infected and uninfected cells were isolated from the central nitrogen fixing tissue of French bean (Phaseolus vulgaris L. cv Contender) root nodules. Successive filtrations allowed the separation of the infected cells, whereas the small uninfected cells were isolated on a discontinuous Percoll gradient... |
ADPglucose pyrophosphorylase (EC 2.7.7.27) has been purified from two cyanobacteria: the filamentous, heterocystic, Anabaena PCC 7120 and the unicellular Synechocystis PCC 6803. The purification procedure gave highly purified enzymes from both cynobacteria with specific activities of 134 (Synechocystis) and 111 (Anabae... |
We compared nodule initiation in lateral roots of Pisum sativum (L.) cv Sparkle and in a low-nodulating mutant E2 (sym 5). In Sparkle, about 25% of the infections terminated in the epidermis, a similar number stopped in the cortex, and 50% resulted in the formation of a nodule meristem or an emerged nodule. The mutant ... |
Vascular bundles were isolated from grapefruit (Citrus paradisi Macf.) during periods of rapid sucrose translocation into fruit. Invertase and sucrose synthase activities were assayed in these strands and compared with immediately adjacent tissues (inner most peel and segment epidermis) and phloem-free juice sacs durin... |
The levels of abscisic acid (ABA) during embryogenesis in the soybean (Glycine max) cultivar Dare were quantitated. An increase in the quantity of ABA per cotyledon was correlated with a decrease in the chlorophyll a/b binding (Cab) protein gene mRNA population. Soybean cotyledons were cultured in vitro in the presence... |
Tobacco (Nicotiana tabacum var Samsun) was transformed using the bacterial gor gene coding for the enzyme glutathione reductase. Transgenic plants were selected by their kanamycin resistence and expression of the bacterial gor gene. After separation by isoelectric focusing techniques, leaf extracts from transgenic plan... |
The herbicide chlorate has been used extensively to isolate mutants that are defective in nitrate reduction. Chlorate is a substrate for the enzyme nitrate reductase (NR), which reduces chlorate to the toxic chlorite. Because NR is a substrate (NO(3) (-))-inducible enzyme, we investigated the possibility that chlorate ... |
The regulation of 2-carboxyarabinitol 1-phosphatase (CA 1-Pase) by phosphorylated effectors was studied with enzyme purified from tobacco (Nicotiana tabacum) leaves. CA 1-Pase activity was most stimulated by fructose 1,6-bisphosphate, exhibiting an A(0.5) value of 1.9 millimolar and a 10-fold enhancement of catalysis. ... |
The large subunit (LS) of tobacco (Nicotiana rustica) ribulose-1,5-bisphosphate carboxylase/oxygenase (ribulose-P(2) carboxylase) contains a trimethyllysyl residue at position 14, whereas this position is unmodified in spinach ribulose-P(2) carboxylase. A protein fraction was isolated from tobacco chloroplasts by rate-... |
Posttranslational modifications that give rise to multiple forms of alpha-amylase (EC 3.2.1.1) in barley (Hordeum vulgare L. cv Himalaya) were studied. When analyzed by denaturing polyacrylamide gel electrophoresis, barley alpha-amylase has a molecular mass of 43 to 44 kilodaltons, but isoelectric focusing resolves the... |
The active transport of CO(2) in Synechococcus UTEX 625 was measured by mass spectrometry under conditions that preclude HCO(3) (-) transport. The substrate concentration required to give one half the maximum rate for whole cell CO(2) transport was determined to be 0.4 +/- 0.2 micromolar (mean +/- standard deviation; n... |
The cytosolic isoform of ascorbate peroxidase was purified to homogeneity from 14-day-old pea (Pisum sativum L.) shoots. The enzyme is a homodimer with molecular weight of 57,500, composed of two subunits with molecular weight of 29,500. Spectral analysis and inhibitor studies were consistent with the presence of a hem... |
In functioning eucalypt ectomycorrhizas, biochemical alterations are accompanied by a differential accumulation of polypeptides including the synthesis of symbiosis-related proteins (JL Hilbert, Martin FM [1988] New Phytol 110: 339-346). In the present study, protein biosynthesis in the early stages of ectomycorrhiza f... |
Chorismate synthase was purified 1200-fold from Euglena gracilis. The molecular mass of the native enzyme is in the range of 110 to 138 kilodaltons as judged by gel filtration. The molecular mass of the subunit was determined to be 41.7 kilodaltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Purified ... |
Formation of the stilbenes pinosylvin and pinosylvin 3-methyl ether, as well as the activity of the biosynthetic enzyme stilbene synthase (pinosylvin-forming), were induced several hundred- to thousandfold in primary needles of 6-week-old pine (Pinus sylvestris L.) seedlings upon exposure to a single pulse of ozone of ... |
Mesophyll and paraveinal mesophyll protoplasts (PVMP) were isolated from leaves of soybean (Glycine max) at various stages of physiological development, and protein compositions of the two protoplast types were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. Polypeptides of 27,... |
Mitochondria isolated from the taproot of beet (Beta vulgaris) were used in an effort to identify and partially purify the proteins constituting the exogenous NADH dehydrogenase. Three NAD(P)H dehydrogenases are released from these mitochondria by sonication, and these enzymes were partially purified using fast protein... |
We have purified homoserine dehydrogenase to homogeneity and subjected polypeptide fragments derived from digests of the protein to amino acid sequencing. The amino acid sequence of homoserine dehydrogenase from carrot (Daucus carota) indicates that in carrot both aspartokinase and homoserine dehydrogenase activities r... |
The procedure of Malhotra and Kayastha ([1990] Plant Physiology 93: 194-200) for the purification to homogeneity of a phosphoenolpyruvate-specific alkaline phosphatase (PEP phosphatase) from germinating mung beans (Vigna radiata) was followed. Although a higher specific activity of 1.4 micromoles pyruvate produced per ... |
Acetohydroxyacid synthase (AHAS), the first enzyme leading to the biosynthesis of valine, leucine, and isoleucine, is inhibited by different chemical classes of herbicides. There is a loss in the extractable AHAS activity in imidazolinone-treated plants. Immunological studies using a monoclonal antibody against AHAS re... |
Leucoplast pyruvate kinase (PK(p); EC 2.7.1.40) from endosperm of developing castor oil seeds (Ricinus communis L. cv Baker 296) appears to be highly susceptible to limited degradation by a cysteine endopeptidase during the purification of the enzyme or incubation of clarified homogenates at 4 degrees C. Purified casto... |
Xylulose 1,5-bisphosphate (XuBP) is synthesized from ribulose 1,5-bisphosphate (RuBP) at carbamylated catalytic sites on ribulose 1,5-bisphosphate carboxylase (Rubisco) with significant amounts of XuBP being formed at pH less than 8.0. XuBP has been separated by high performance liquid chromatography and identified by ... |
During ear development in maize (Zea mays L.), nitrogenous compounds are translocated from vegetative organs to the kernels. At anthesis, the stalk contains approximately 40% of the total plant N, and contributes 45% of the N remobilized to the ear. Therefore, the stalk has an important function as a temporary reservoi... |
A method to fractionate corn (Zea mays L. B73) mitochondria into soluble proteins, high molecular weight soluble proteins, and membrane proteins was developed. These fractions were analyzed by both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and assays of mitochondrial enzyme activities. The Krebs cycle e... |
We have monitored the activities of RNases WL(A), WL(B), and WL(C) (A Blank, TA McKeon [1991] Plant Physiol 97: 1402-1408) during leaf senescence in wheat (Triticum aestivum L. cv Chinese Spring). When seedlings were induced to senesce in darkness, protein loss from primary leaves began immediately. RNase WL(B) activit... |
Synthesis of heat shock proteins (HSPs) in the leaves of a drought- and heat-resistant (line ZPBL 1304), and a drought- and heat-sensitive (line ZPL 389) line of maize (Zea mays L.) was studied under two environmental stress treatments: (a) soil drying and high temperature and (b) high temperature. In the first treatme... |
Thalli discs of the marine macroalga Ulva lactuca were given inorganic carbon in the form of HCO(3) (-), and the progression of photosynthetic O(2) evolution was followed and compared with predicted O(2) evolution as based on calculated external formation of CO(2) (extracellular carbonic anhydrase was not present in th... |
The tomato (Lycopersicon esculentum) acid phosphatase-1 (Apase-1(1), EC 3.1.3.2) isozyme variant, genetically linked to the root-knot nematode resistance locus (Mi) on chromosome 6, has been purified by a rapid procedure from tomato cell suspension cultures. Peptide fragments of the purified enzyme were generated from ... |
Phosphoenolpyruvate carboxylase (PEPcase) activity was studied in excised leaves of wheat (Triticum aestivum L.) in the dark and in the light, in presence of either N-free (low-NO(3) (-) leaves) or 40 millimolar KNO(3) (high-NO(3) (-) leaves) nutrient solutions. PEPcase activity increased to 2.7-fold higher than that m... |
Tomato (Lycopersicon esculentum Mill.) cell suspension cultures accumulated wall-bound phenolic materials in response to inoculation with Verticillium albo-atrum Reinke et Berth. in a fashion analogous to that observed in whole plants. Both monomeric and polymeric materials were recovered. Deposition of phenolics into ... |
Desiccation tolerance of the moss Tortula ruralis is characterized by a desiccation-induced change in gene expression that becomes evident upon rehydration. As reported earlier, this change in gene expression is apparently brought about by a change in the control of translation and does not include a major shift in mRN... |
Soybean (Glycine max) plants accumulate a vacuolar glycoprotein in the parenchymal cells of leaves, petioles, stems, seed pods, and germinating cotyledons that acts in temporary nitrogen storage during vegetative growth. In situ immunolocalization of this vegetative storage protein (VSP) revealed that it accumulates in... |
Ca(2+)-ATPases keep cytoplasmic [Ca(2+)] low by pumping Ca(2+) into intracellular compartments or out of the cell. The transport properties of Ca(2+)-pumping ATPases from carrot (Daucus carota cv Danvers) tissue culture cells were studied. ATP-dependent Ca(2+) transport in vesicles that comigrated with an endoplasmic r... |
Photosynthetic capacity of isolated intact chloroplasts is known to be sensitive to K(+) fluxes across the chloroplast envelope. However, little is known about the system of chloroplast envelope proteins that regulate this K(+) movement. The research described in this report focused on characterizing some of the compon... |
In organello starch biosynthesis was studied using intact chloroplasts isolated from spinach leaves (Spinacia oleracea). Immunoblot analysis using a specific antiserum against the mitochondrial adenylate (ADP/ATP) translocator of Neurospora crassa shows the presence of an adenylate translocator protein in the chloropla... |
A simple procedure that yields highly purified intact chloroplasts from Chlamydomonas reinhardtii is described. This procedure involves breakage of cell wall-deficient cells by passing them through a narrow bore syringe needle. The intact chloroplasts are then purified from the crude homogenate by differential centrifu... |
Experiments were conducted with a tobacco (Nicotiana tabacum) mutant with 40 to 50% greater catalase activity than wild type that is associated with a novel form of O(2)-resistant photosynthesis. The apparent K(m) for H(2)O(2) was the same in mutant and wild-type leaf extracts. Tobacco RNAs were hybridized with Nicotia... |
Aspen (Populus tremuloides Michx.) leaf extracts contain a newly discovered enzyme activity that catalyzes the magnesium ion-dependent elimination of diphosphate from dimethylallyl diphosphate with rearrangement to form isoprene (2-methyl, 1-3-butadiene). This isoprene synthase activity has been partially purified. The... |
We have described the inhibition of polar auxin transport by several phytotropins including 1-N-naphthylphthalamic acid (NPA) and quercetin. Semicarbazones (substituted phenylsemicarbazones of 2-acetylarylcarboxylic acids) are inhibitors consistent with previously predicted general structural requirements for auxin tra... |
Cells of yellow-poplar (Liriodendron tulipifera L.) were transformed by direct gene transfer and regenerated into plants by somatic embryogenesis. Plasmid DNA bearing marker genes encoding beta-glucuronidase (GUS) and neomycin phosphotransferase (NPT II) were introduced by microprojectile bombardment into single cells ... |
Cinnamyl alcohol dehydrogenase (CAD) is an enzyme involved in lignin biosynthesis. In this paper, we report the purification of CAD to homogeneity from tobacco (Nicotiana tabacum) stems. The enzyme is low in abundance, comprising approximately 0.05% of total soluble cell protein. A simple and efficient purification pro... |
Polyclonal antibodies against victorin, the host-specific toxin produced by Cochliobolus victoriae, were raised in rabbits immunized with a victorin-bovine serum albumin conjugate. The antibodies were purified from serum by protein A column chromatography and characterized by indirect and direct enzymelinked immunosorb... |
C(4) phosphoenolpyruvate carboxylase (PEPC) is post-translationally regulated by reversible phosphorylation of a specific N-terminal seryl residue in response to light/dark transitions of the parent leaf tissue. The protein-serine kinase (PEPC-PK) that phosphorylates/activates this mesophyll-cytoplasm target enzyme is ... |
Banana (Musa acuminata, cv Dwarf Cavendish) proteins were extracted from pulp tissue at different stages of ripening and analyzed by two-dimensional electrophoresis. The results provide evidence of differential protein accumulation during ripening. Two sets of polypeptides have been detected that increase substantially... |
A polypeptide structurally related to the thaumatin family of proteins has been purified from soybean (Glycine max) leaves and the complete amino acid sequence has been determined. The mature protein, which we have termed P21, has a calculated molecular weight of 21,461 and an isoelectric point of 4.6. The soybean prot... |
Maize (Zea mays L.) beta-glucosidase (beta-d-glucoside glucohydrolase, EC 3.2.1.21) was extracted from the coleoptiles of 5- to 6-day-old maize seedlings with 50 millimolar sodium acetate, pH 5.0. The pH of the extract was adjusted to 4.6, and most of the contaminating proteins were cryoprecipitated at 0 degrees C for ... |
The pigmentation of Petunia hybrida corollas is regulated by gibberellic acid (GA(3)). It controls the increase of flavonoid enzyme levels and their corresponding mRNAs. We have used an in vitro culture system for corollas to study the regulatory role of GA(3) in the expression of flavonoid genes. By determining steady... |
We have characterized the occurrence and expression of multiple acyl carrier protein (ACP) isoforms in Arabidopsis thaliana (L.) Heynh ecotype Columbia. Immunoblot analysis of ACPs from Arabidopsis tissues separated by native polyacrylamide gel electrophoresis and 1 molar urea polyacrylamide gel electrophoresis reveale... |
Squalene synthetase, an integral membrane protein and the first committed enzyme for sterol biosynthesis, was solubilized and partially purified from tobacco (Nicotiana tabacum) cell suspension cultures. Tobacco microsomes were prepared and the enzyme was solubilized from the lipid bilayer using a two-step procedure. M... |
The light-harvesting complex (LHC) of photosystem II is composed of several different pigment-binding apoproteins. We have identified a cDNA clone LHCIIa-1 encoding the 31-kilodalton LHC IIa (CP29, Chl a/b-P1) apoprotein of barley (Hordeum vulgare). Direct protein microsequencing of an internal peptide fragment from th... |
An immunoglobulin Mk monoclonal (F8IVE9) antibody raised against oat (Avena sativa cv Garry) root homogenate has been produced and characterized. The predominant target bound by this antibody is a 62-kilodalton protein (p62) that is expressed in both oat root and oat shoot cells. Treatment of the oat antigen with perio... |
The protein contents of mitochondria from different potato (Solanum tuberosum L.) tissues (tubers, dark-grown shoots, and green leaves) grown in a greenhouse or in vitro were compared by two-dimensional polyacrylamide gel electrophoresis. Two different methods were used: using the method that gave the highest resolutio... |
Excision of developing potato (Solanum tuberosum L.) tubers from the mother plant, followed by storage at 10 degrees C, resulted in a rapid, substantial decrease in sucrose synthase activity and considerable increases in hexose content and acid invertase activity. A comparison of the response of three genotypes, known ... |
A complementary DNA for the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was cloned from tobacco (Nicotiana tabacum) and fused in the antisense orientation to the cauliflower mosaic virus 35S promoter. This antisense gene was introduced into the tobacco genome, and the resulting transgenic... |
A glyoxysomal copper,zinc-containing superoxide dismutase (EC 1.15.1.1) was purified to homogeneity, for the first time, from watermelon cotyledons (Citrullus vulgaris Schrad.). The stepwise purification procedure consisted of acetone precipitation, batch anion-exchange chromatography, anion-exchange Fast Protein Liqui... |
Tobacco proteins that share homology with thaumatin, a sweet protein of Thaumatococcus daniellii Benth., are produced in various physiological situations such as pathogenesis-related stress or water deficit stress. Using purified polyclonal anti-thaumatin antibodies, we have detected other thaumatin-like proteins in to... |
Phenylalanine ammonia-lyase (EC 4.3.1.5) has been purified from differentiating secondary xylem of loblolly pine (Pinus taeda L.). Native molecular weight of the enzyme was estimated to be 280,000, with a subunit molecular weight of 74,000; isoelectric point, 5.8; and Michaelis constant for i-phenylalanine, 27 micromol... |
The 2',3'-dialdehyde derivative of ATP (dial-ATP) has been shown to be an affinity label for the ATP binding site of the H(+)-ATPase from tonoplast of etiolated mung bean seedlings (Vigna radiata L.). The dial-ATP caused marked inactivation of enzymatic activities of both membrane-bound and soluble ATPase and its assoc... |
Phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) is involved in the lignification of pine suspension cultures in response to an elicitor prepared from an ectomycorrhizal fungus. To elucidate the molecular basis of this response, PAL was purified to homogeneity from jack pine (Pinus banksiana) suspension cultures using ani... |
To study gene regulation during the transition from late embryogeny to germination, we have analyzed the expression of a gene encoding the glyoxylate cycle enzyme malate synthase in transgenic tomato (Lycopersicon esculentum) plants. We have shown that although there are at least four classes of malate synthase genes i... |
A unique phosphoribulokinase (ADP:D-ribulose 5-phosphate 1-phosphotransferase, EC 2.7.1.19) has been purified to homogeneity from the green alga Selenastrum minutum. The enzyme has a native molecular mass of about 83 kilodaltons and a native isoelectric point of 5.1. The enzyme consists of two different-sized subunits ... |
Addition of catecholamines at micromolar concentrations caused a dramatic stimulation of growth of tobacco (Nicotiana tabacum) thin cell layers (TCLs) and Acmella oppositifolia "hairy" root cultures. A threefold increase in the rate of ethylene evolution was observed in the catecholamine-treated explants. Aminooxyaceti... |
Shoots of germinating rice (Oryza sativa L.) seedlings are able to grow under anoxia and to withstand long periods of anoxic treatment. Mitochondria were purified from aerobically germinated and anaerobically treated rice shoots by differential and isopycnic centrifugation and were found to consist of two subpopulation... |
In Chlamydomonas reinhardtii mutants defective at the structural locus for nitrate reductase (nit-1) or at loci for biosynthesis of the molybdopterin cofactor (nit-3, nit-4, or nit-5 and nit-6), both nitrite uptake and nitrite reductase activities were repressed in ammonium-grown cells and expressed at high amounts in ... |
A family of specific guanine nucleotide-binding proteins in Dunaliella salina was studied. Polypeptides of different subcellular fractions were separated by electrophoresis and transferred to nitrocellulose or Immobilon membranes. Incubation of the transfer blots with [(35)S]GTPgammaS or [alpha-(32)P]GTP showed no evid... |
The expression of maize (Zea mays) phophoenolpyruvate carboxylase (PPC) gene constructions was studied in transgenic tobacco plants (Nicotiana tabacum). Where transcription was under the control of a maize PPC gene promoter, a low level of aberrantly large PPC transcript was detected. Analysis of this PPC transcript in... |
Polyphenoloxidase was purified from chloroplasts of broad bean leaves (Vicia faba L.) to apparent homogeneity. The enzyme was composed of two proteins with an apparent mass of 65 and 68 kilodaltons after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isolated enzyme contained covalently attached carbohy... |
(31)P-, (13)C-, and (15)N-nuclear magnetic resonance spectroscopy were used to determine the roles of malate, succinate, Ala, Asp, Glu, Gln, and gamma-aminobutyrate (GABA) in the energy metabolism and regulation of cytoplasmic pH in hypoxic maize (Zea mays L.) root tips. Nitrogen status was manipulated by perfusing roo... |
Potato (Solanum tuberosum L.) tubers contain two isoenzymes of 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (EC 4.1.2.15), the enzyme that catalyzes the first step of aromatic amino acid biosynthesis. One of the isoenzymes is specifically activated by Mn(2+), and the other requires Co(2+), Mg(2+), or another di... |
Antioxidant metabolites in eastern white pine (Pinus strobus L.) needles increased two- to fourfold from the summer to the winter season. Antioxidant enzymes in needle tissue increased between 2- and 122-fold during this same period. These seasonal changes were determined by monitoring ascorbate and glutathione concent... |
The effect of short-term water stress on photosynthesis of two sunflower hybrids (Helianthus annuus L. cv Sungro-380 and cv SH-3622), differing in productivity under field conditions, was measured. The rate of CO(2) assimilation of young, mature leaves of SH-3622 under well-watered conditions was approximately 30% grea... |
The existence of multiple forms of avocado (Persea americana Mill. cv Hass) cellulase in crude protein extracts of ripe avocado fruit is reported. Cellulase was separated into at least 11 multiple forms by native isoelectric focusing in the pH range between 4 and 7 and visualized by both activity staining using Congo r... |
The small subunit (SSU) of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) possesses a binding site that can be photoaffinity labeled with [(32)P]8-azidoadenosine 5' triphosphate (N(3)ATP). In the present study, photoaffinity labeling was used to compare the nucleotide analog binding properties of SSU in the ... |
Fruit ripening involves a series of changes in gene expression regulated by the phytohormone ethylene. AVOe3, a ripening-related gene in avocado fruit (Persea americana Mill. cv Hass), was characterized with regard to its ethylene-regulated expression. The AVOe3 mRNA and immunopositive protein were induced in mature fr... |
Carbonyl sulfide (COS), a substrate for carbonic anhydrase, inhibited alkalization of the medium, O(2) evolution, dissolved inorganic carbon accumulation, and photosynthetic CO(2) fixation at pH 7 or higher by five species of unicellular green algae that had been air-adapted for forming a CO(2)-concentrating process. T... |
Northern analysis has revealed substantial differences in mRNA accumulation of the two histone H3 gene variants represented by pH3c-1 and pH3c-11 cDNA clones. Both in partially synchronized cell suspension cultures and in protoplast-derived cells from alfalfa, Medicago varia, the maximal level of the histone H3-1 gene ... |
The facultative halophyte Mesembryanthemum crystallinum responds to salt stress by increasing the levels of phosphoenolpyruvate carboxylase (PEPCase) and other enzymes associated with Crassulacean acid metabolism. A more common response to salt stress in sensitive and tolerant species, including M. crystallinum, is the... |
Bark storage proteins accumulate in the bark of many woody plants during autumn and winter. In poplar (Populus deltoides Bartr. ex Marsh), the accumulation of the 32-kilodalton bark storage protein is controlled by photoperiod. We have isolated a full-length cDNA encoding for the poplar 32-kilodalton bark storage prote... |
In a recent paper (P Ohana, DP Delmer, JC Steffens, DE Matthews, R Mayer, M Benziman [1991] J Biol Chem 266: 13472-13475), we described the purification and structural characterization of beta-furfuryl-beta-glucoside (FG), an endogenous activator of plant UDP-glucose:(1-->3)-beta-glucan (callose) synthase. In the prese... |
Elicitor induction of phenylpropanoid metabolism was investigated in suspension-cultured cells of the fast-growing poplar hybrid (Populus trichocarpa Torr. & Gray x Populus deltoides Marsh) H11-11. Treatment of cells with polygalacturonic acid lyase or two fungal elicitors resulted in rapid and transient increases in e... |
Appearance of a lag period dependent on pH in the expression of the catecholase activity of a polyphenoloxidase extracted in a latent state from Airen grape (Vitis vinifera L.) berries, is revealed, suggesting the hysteretic nature of the enzyme. The lag time was independent of enzyme concentration, indicating that slo... |
The effect of 5-5'-dithiobis-2-nitrobenzoate (DTNB) on the kinetic parameters and structure of phosphoenolpyruvate carboxylase purified from maize (Zea mays L.) has been studied. The V(max) is found to be independent of the presence of this thiol reagent. The K(m) is increased upon oxidation of cysteines by DTNB. At a ... |
The cyanobacterium Agmenellum quadruplicatum PR-6 (Synechococcus sp PCC 7002) was grown turbidostatically in white light at three levels of irradiance: 20, 200, and 1260 microeinsteins per square meter per second. Phycobilisomes were isolated from each culture and analyzed by absorbance, gel electrophoresis, and electr... |
Proplastids and etioplasts are common starting points for monitoring chloroplast development in higher plants. Although proplastids are the primary precursor of chloroplasts, most proplastid to chloroplast systems are cumbersome to study temporally. Conversely, the etioplast to chloroplast transition is initiated by li... |
The subcellular site of the posttranslational modification of alpha-amylase was investigated in aleurone layers of barley (Hordeum vulgare L. cv Himalaya). Aleurone layers of Himalaya barley synthesize and secrete two groups of alpha-amylase isoforms, referred to as low-isoelectric point (low-pl) or HAMY1 and high-pl o... |
The starchy endosperm (SE) of the developing grain (caryopsis) of barley (Hordeum vulgare L.) cv Himalaya, as well as that of other barley cultivars examined, acidifies during maturation. The major decrease in pH begins with the attainment of maximum grain dry weight, onset of dehydration, and completion of chlorophyll... |
A polyadenylate-binding protein (PABP) was purified from cell-free extracts prepared from pea seedlings (Pisum sativum) by ammonium sulfate precipitation and Affi-Gel Blue and polyadenylate-Sepharose 4B affinity chromatography. The final preparation from polyadenylate-Sepharose 4B columns contained a single 70-kilodalt... |
Lysine-ketoglutarate reductase catalyzes the first step of lysine catabolism in maize (Zea mays L.) endosperm. The enzyme condenses l-lysine and alpha-ketoglutarate into saccharopine using NADPH as cofactor. It is endosperm-specific and has a temporal pattern of activity, increasing with the onset of kernel development... |
Diacylglycerol kinase (adenosine 5'-triphosphate:1,2-diacylglycerol 3-phosphotransferase, EC 2.7.1.107), purified from suspension cultured Catharanthus roseus cells (J Wissing, S Heim, KG Wagner [1989] Plant Physiol 90: 1546-1551), was further characterized and its subcellular location was investigated. The enzyme reve... |
Here it is reported that sucrose synthase can be readily measured in growing wild tomato fruits (Lycopersicon chmielewskii) when suitable methods are adopted during fruit extraction. The enzyme also was present in fruit pericarp tissues, in seeds, and in flowers. To check for novel characteristics, the wild tomato frui... |
Isoprene emissions from the leaves of velvet bean (Mucuna pruriens L. var utilis) plants exhibited temperature response patterns that were dependent on the plant's growth temperature. Plants grown in a warm regimen (34/28 degrees C, day/night) exhibited a temperature optimum for emissions of 45 degrees C, whereas those... |
Glutamate dehydrogenase (GDH) specific activity and function have been studied in cell suspension cultures of carrot (Daucus carota L. cv Chantenay) in response to carbon and nitrogen supply in the culture medium. The specific activity of GDH was derepressed in sucrose-starved cells concomitant with protein catabolism,... |
In this work, we exploited the capability of the plasma membrane Ca-ATPase to utilize ITP as a substrate to study its characteristics in plasma membrane vesicles purified from radish (Raphanus sativus L.) seedlings. The majority of the ITPase activity of plasma membrane was Ca(2+)-dependent. The Ca(2+)-dependent ITPase... |
The effect of calmodulin on the activity of the plasma membrane Ca-ATPase was investigated on plasma membranes purified from radish (Raphanus sativus L.) seedlings. Calmodulin stimulated the hydrolytic activity and the transport activity of the plasma membrane Ca-ATPase to comparable extents in a manner dependent on th... |
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