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covalent labelling of the nadph: protochlorophyllide oxidoreductase from etioplast membranes with [3h]n-phenylmaleimide.[3h]n-phenylmaleimide has been used to covalently label in a specific manner the substrate-protected thiol groups of the enzyme protochlorophyllide reductase. in membrane preparations from oat (avena sativa) and runner-bean (phaseolus vulgaris) seedlings, two related peptides of mol.wts. 35000/37000 and 34000/35000 respectively and showing properties expected of the reductase have been identified, whereas the same technique with barley (hordeum vulgare) extracts resulted in labelling a single pe ...19817306063
characterization of the inhibition of k absorption in oat roots by salicylic acid.the phenolic compounds salicylic acid (o-hydroxybenzoic acid) and ferulic acid (4-hydroxy-3-methoxycinnamic acid) inhibited k(+) ((86)rb(+)) absorption in excised oat (avena sativa l. cv. goodfield) root tissue. salicylic acid was the most inhibitory. the degree of inhibition was both concentration- and ph-dependent. with decreasing ph, the inhibitory effect of the phenolic increased. during the early stages of incubation, the time required to inhibit k(+) absorption was also ph- and concentrati ...198116662106
use of lilium longiflorum, cv. ace pollen germination and tube elongation as a bioassay for the hepatocarcinogens, aflatoxins.although various animal tissues are used for bioassay of aflatoxins (b1, b2, g1, g2), a rapid bioassay dependent upon a plant part's response does not exist. both pollen germination (g) and tube elongation (te) were enhanced in a 3.0 mm kh2po4 (k)-containing but afb1-lacking, modified dickinson's medium. the b1 did not affect g when k was withheld but k supplementation impaired g above 15 micrograms/ml b1. without k, 5-20 stimulated but 25 and 30 micrograms/ml b1 inhibited te which was suppresse ...19817274186
chlorophyll biosynthesis by mesophyll protoplasts and plastids from etiolated oat (avena sativa l.) leaves.the uptake of [1-(3)h]geranylgeranyl diphosphate (ggpp) into protoplasts and intact etioplasts and the metabolic interconversion therein was studied after a 2 min pulse of white light. the chlorophyll synthetase reaction, chlide+ggpp→chlgg, was taken as a natural probe for the etioplast compartment. this reaction yields labeled chlgg and, by hydrogenation, labeled chlp, when [1-(3)h]ggpp receives access to the etioplast stroma. it was found that penetration across the plastid envelope was rapid ...198124302319
changes in endogenous gibberellins and the metabolism of [h]ga(4) after geostimulation in shoots of the oat plant (avena sativa).the recovery from "lodging," or bending over, by shoots of 42-day-old avena sativa plants is controlled primarily by a negatively geotropic differential growth of the lower halves of the p-1 node-pulvinus and the base of the p-1 internode, relative to the upper halves. although geostimulation causes a significant reduction in p-1 internode length, dry matter accumulation in the p-1 node-pulvinus is increased, apparently at the expense of the sheath. recovery to an angle of 30 degrees is associat ...198116661788
phytochrome control of two low-irradiance responses in etiolated oat seedlings.light-induced coleoptile stimulation and mesocotyl suppression in etiolated avena sativa (cv. lodi) has been quantitated. etiolated seedlings showed the greatest response to light when they were illuminated 48 to 56 hours after imbibition. two low-irradiance photoresponses for each tissue have been described. red light was 10 times more effective than green and 1,000 times more effective than far red light in evoking these responses. the first response, which resulted in a 45% mesocotyl suppress ...198116661745
fusion of avena sativa mesophyll cell protoplasts by electrical breakdown.studies with the light microscope were carried out on mesophyll cell protoplasts of avena sativa which had been made to undergo fusion by reversible electrical breakdown of the cell membrane. in order to establish close membrane contact between the cells, an important prerequisite for fusion, a method known as dielectrophoresis was used. in an inhomogeneous alternating electrical field the protoplasts adhere to the electrodes and to each other in the direction of the field lines. the cells which ...19817213711
physicochemical differences between the red- and the far-red-absorbing forms of phytochrome.we investigated some of the chemical and physical differences between the red-absorbing (pr) and far-red-absorbing (pfr) forms of immunoaffinity-purified, undegraded oat (avena sativa l., ev. garry) phytochrome. both pr and pfr had identical surface charges as measured by isoelectric focusing and identical secondary structure as judged from their circular dichroic spectra. modification of specific amino acid residues, however, revealed some chemical differences between pr and pfr. compared to pr ...19817213624
biomass production of c3- and c4-plant species in pure and mixed culture with different water supply.pure and mixed cultures of the dicotyledons atriplex hortensis l. (c3 plant) and amaranthus retroflexus l (c4) on the one hand and of the grasses avena sativa l (c3) and panicum miliaceum l. (c4) on the other hand were maintained in a standard soil with different ground water tables. after 12 weeks the length, dry weight and nitrogen-content of the aboveground and belowground parts of the plants, and in addition the carbon-and ash-content and the δ(13)c value of the aboveground parts were determ ...198128310064
rotation of cells in an alternating electric field: the occurrence of a resonance frequency.cells suspended in a low-conducting medium were exposed to an alternating electric field whose frequency was altered between 1 khz and 2 mhz. a resonance frequency was observed at which all suspended cells rotated about an axis normal to the field lines (when the electric field strength was larger than a threshold value of about 400 v/cm). this resonance frequency varied from species to species of cells (mesophyll protoplasts of avena sativa = 20-40 khz, human erythrocytes and ghost cells = 80-1 ...19817010816
immunopurification and initial characterization of dicotyledonous phytochrome.antiserum was prepared against proteolytically undegraded phytochrome obtained from etiolated zucchini squash (cucurbita pepo l., cv. black beauty). the antiserum was prepared by injecting into a rabbit immunoprecipitates between zucchini phytochrome and specific antiserum against undegraded oat (avena sativa l., cv. garry) phytochrome. specific antiphytochrome immunoglobulins were purified from this crude serum by an affinity column consisting of conventionally purified undegraded pea phytochro ...198216662209
evidence from studies with acifluorfen for participation of a flavin-cytochrome complex in blue light photoreception for phototropism of oat coleoptiles.the diphenyl ether acifluorfen enhances the blue light-induced absorbance change in triton x100-solubilized crude membrane preparations from etiolated oat (avena sativa l. cv. lodi) coleoptiles. enhancement of the spectral change is correlated with a change in rate of dark reoxidation of a b-type cytochrome. similar, although smaller, enhancement was obtained with oxyfluorfen, nitrofen, and bifenox. light-minus-dark difference spectra in the presence and absence of acifluorfen, and the dithionit ...198216662593
comparative phytochrome immunochemistry as assayed by antisera against both monocotyledonous and dicotyledonous phytochrome.preparation and characterization of antisera against lettuce (lactuca sativa l., cv. grand rapids) and pea (pisum sativum l., cv. alaska) phytochrome is described. these antisera, together with previously obtained antisera against zucchini (cucurbita pepo l., cv. black beauty) and oat (avena sativa l., cv. garry) phytochrome, were used to compare by ouchterlony double immunodiffusion phytochrome isolated from etiolated lettuce, pea, bean (phaseolus vulgaris l., cv. taylor horticultural bush), zu ...198216662599
relation of polyamine synthesis and titer to aging and senescence in oat leaves.polyamine biosynthesis in senescing leaves of avena sativa l. was measured by determining the activities of arginine decarboxylase (ec 4.1.1.19), ornithine decarboxylase (ec 4.1.1.17) and s-adenosyl-l-methionine decarboxylase (ec 4.1.1.50). polyamine content was also estimated by thin layer chromatography and high performance liquid chromatography. arginine decarboxylase activity decreases progressively in aging attached first leaves and in senescing excised leaves in the dark. conversely, it in ...198216662218
localization of phytochrome in oats by electron microscopy.phytochrome was localized by immunoelectron microscopy in cells of the coleoptile tip of etiolated and irradiated oat (avena sativa l., cv. konata) seedlings. by using ultrathin frozen sections and immunopurified, monospecific antibodies, both the sensitivity and resolution of the immunocytochemical assay were increased. the results with etiolated plants agree with and extend previously published data. a brief red light illumination caused the redistribution of phytochrome from a diffuse to a mo ...198216662591
sources of ammonium in oat leaves treated with tabtoxin or methionine sulfoximine.excised 7-day-old oat (avena sativa l. cv. jaycee) leaves were incubated in media containing 7.1 millimolar kno(3) and 0.15 millimolar tabtoxin or 1 millimolar methionine sulfoximine (mso) to investigate the sources of the observed ammonium accumulated. tabtoxin and mso are known inhibitors of glutamine synthetase, the first enzyme in the primary pathway of ammonium assimilation. during a 4- to 6-hour incubation, there was little net change in protein or total amino acid concentration. alanine, ...198216662206
osmoregulation in the avena coleoptile : control of solute uptake in peeled sections.peeled avena sativa coleoptile sections (i.e. sections from which the epidermis has been removed) have been used to study the control of solute uptake under conditions where the uptake is not limited by the cuticular barrier. in the presence of 2% sucrose, auxin enhances the rate at which the total osmotic solutes increase, but this appears to be a response to the increased growth rate, inasmuch as the auxin effect is eliminated when growth is inhibited osmotically. when sections are incubated i ...198216662195
pyruvate orthophosphate dikinase from the immature grains of cereal grasses.pyruvate orthophosphate dikinase has been identified in the green grains of eight cereal grasses, most of which are classified as c(3) plants. the wheat (triticum aestivum l. cv. lerma rojo) grain enzyme was further investigated: activity was low in very young grains, increased to a maximum at about 25 days after anthesis, then returned to a low level as the grain matured. it appeared to be located in the aleurone layer. a procedure was developed for obtaining partially purified preparations of ...198216662187
does ethylene play a role in the release of lateral buds (tillers) from apical dominance in oats?the growth of lateral buds (tillers), which are undergoing release from apical dominance, was measured in upright and gravistimulated intact avena sativa l. cv. ;victory' (oat) shoots as well as in isolated avena stem segments treated with kinetin and sucrose. during release, the tiller bud initially shows a slow rate of elongation accompanied by swelling. it is followed by a more rapid rate of elongation. ethylene (c(2)h(4)) production in shoot segments containing a tiller bud was found to occu ...198216662580
ethylene as an effector of wound-induced resistance to cellulase in oat leaves.peeling the abaxial epidermis from oat leaves (avena sativa var. victory) induces the formation of wound ethylene and the development of resistance to cellulolytic digestion of mesophyll cell walls. ethylene release begins between 1 and 2 hours after peeling in the light or dark. aminoethoxyvinylglycine (avg, 0.1 millimolar), cocl(2) (1.0 millimolar), propyl gallate (pg, 1.0 millimolar) or aminooxyacetic acid (aoa, 1.0 millimolar) inhibits, whereas agno(3) stimulates wound ethylene formation. in ...198216662576
wound-induced resistance to cellulase in oat leaves.peeling the epidermis induces the development of resistance to cellulolytic digestion in the mesophyll cell wals of the first leaf of 1- to 3-week-old oat seedlings (avena sativa var. victory). development of resistance occurs between 3 and 11 hours after the abaxial epidermis is peeled from the blade, and is inhibited by actinomycin d (20 micrograms per milliliter) or cycloheximide (1 microgram per milliliter). other methods of wounding (cutting with a razor blade, stabbing with a dissection ne ...198216662575
rotation of cells in an alternating electric field: theory and experimental proof.protoplasts of avena sativa rotate in an alternating electric field provided that at least two cells are located close to each other. an optimum frequency range (20 to 30 khz) exists where rotation of all cells exposed to the field is observed. below and above this frequency range, rotation of some cells is only occasionally observed. the angular velocity of rotation depends on the square of the electric field strength. at field strengths above the value leading to electrical breakdown of the ce ...19827097755
localization of phytochrome in oats by electron microscopy.phytochrome was localized by immunoelectron microscopy in cells of the coleoptile tip of etiolated and irradiated oat (avena sativa l., cv. konata) seedlings. by using ultrathin frozen sections and immunopurified, monospecific antibodies, both the sensitivity and resolution of the immunocytochemical assay were increased. the results with etiolated plants agree with and extend previously published data. a brief red light illumination caused the redistribution of phytochrome from a diffuse to a mo ...198216662762
plasma membranes from oats prepared by partition in an aqueous polymer two-phase system : on the use of light-induced cytochrome b reduction as a marker for the plasma membrane.presumptive plasma membrane fractions have been prepared from oat (avena sativa l. cv. brighton) roots and shoots, respectively, by partition of microsomal fractions in a dextran-polyethylene glycol two-phase system. the plasma membranes had a high affinity for the polyethylene glycol-rich upper phase, whereas membranes from mitochondria and other organelles partitioned in the dextran-rich lower phase or at the interface. thus, relatively pure plasma membranes were obtained by only two partition ...198216662693
effect of vanadate, molybdate, and azide on membrane-associated atpase and soluble phosphatase activities of corn roots.the effects of vanadate, molybdate, and azide on atp phosphohydrolase (atpase) and acid phosphatase activities of plasma membrane, mitochondrial, and soluble supernatant fractions from corn (zea mays l. wf9 x mo17) roots were investigated. azide (0.1-10 millimolar) was a selective inhibitor of ph 9.0-atpase activity of the mitochondrial fraction, while molybdate (0.01-1.0 millimolar) was a relatively selective inhibitor of acid phosphatase activity in the supernatant fraction. the ph 6.4-atpase ...198216662676
light-induced h secretion and the relation to senescence of oat leaves.when abraded oat (avena sativa l. cv victory) leaf segments are floated on kcl solution, white light causes acidification of the solution external to leaf tissue. the presence of mannitol amplifies the light-induced proton secretion. mature leaves as well as young ones acidify the medium in light, while senescing leaves (after 3 to 4 days incubated in water in the dark) lose the ability to produce this response to light. the decrease in h(+) secretion is already measureable after as little as 30 ...198216662624
synthesis of oat globulin precursors : analogy to legume 11s storage protein synthesisa.the oat (avena sativa l.) seed globulin was found to be synthesized in vitro as 60,000 to 64,000 dalton precursors. in vivo protein labeling yielded polypeptides of 58,000 to 62,000 daltons, suggesting cleavage of signal sequences from the precursors. further cleavage is apparently required to separate the alpha and beta polypeptide sequences which are known to form disulfide-linked 53,000 to 58,000 dalton species in the (alphabeta)(6) holoprotein. the data are discussed with respect to analogou ...198216662760
effects of exogenous 1,3-diaminopropane and spermidine on senescence of oat leaves : ii. inhibition of ethylene biosynthesis and possible mode of action.the effects of the polyamines spermidine and 1,3-diaminopropane on ethylene biosynthesis and chlorophyll (chl) loss were studied in peeled leaves of oat (avena sativa l., var. victory) incubated in the dark. peeling off the epidermal cells induces an increase in 1-aminocyclopropane-1-carboxylate (acc) synthase activity, resulting in an enhanced acc and ethylene formation. both polyamines inhibit ethylene biosynthesis from methionine by inhibiting acc synthase activity and, more effectively, the ...198216662726
effects of exogenous 1,3-diaminopropane and spermidine on senescence of oat leaves : i. inhibition of protease activity, ethylene production, and chlorophyll loss as related to polyamine content.excision and dark incubation of oat (avena sativa l., var. victory) leaves cause a sharp increase in protease activity, which precedes chl loss. both these senescence processes are inhibited by exogenously applied 1,3-diaminopropane (dap), which occurs naturally in leaf segments. the inhibition of protease activity is much greater in vivo than in vitro, suggesting inhibition of protease synthesis as well as protease action by dap. chl breakdown in leaves of radish and broccoli, which also senesc ...198216662725
proteolysis alters the spectral properties of 124 kdalton phytochrome from avena.native phytochrome from avena sativa l. is homogeneous with a monomeric molecular weight of 124 kdalton; 6-10 kdalton larger than the heterogeneous "120" kdalton preparations previously considered to be undegraded (vierstra and quail, 1982, proc. natl. acad. sci. usa, 79: 5272-5276). the phototransformation difference spectrum (pr-pfr) of 124 kdalton phytochrome measured in crude extracts has a minimum in the farred region at 730 nm, the same as that observed in vivo. these spectral properties c ...198224272311
the influence of gibberellic acid and temperature on the growth rate of avena sativa stem segments.a micro-growth measuring technique was used to determine the growth response of stem segments of avena sativa cv. avon to a variety of gibberellic acid (ga(3)) concentrations over a range of incubation temperatures. growth rate varied with ga(3) concentration, the temperature at which the rate was measured, and the growth temperature of the plants prior to excision of the segments. the curves relating segment extension rates to temperature were affected by ga(3) such that the linear portion of t ...198216662529
biological properties of d-amino acid conjugates of 2,4-d.some d-amino acid (glutamic acid, valine, or leucine) conjugates of 2,4-dichlorophenoxyacetic acid (2,4-d) at 10(-5) molar, stimulated elongation of avena sativa l. var mariner coleoptile sections and growth of soybean (glycine max. l. var amsoy) tissue as much as did the l-amino acid conjugates at 10(-6) molar. the d-methionine conjugate did not stimulate growth of soybean root callus tissue but did stimulate avena elongation. the d-aspartic acid conjugate did not stimulate elongation of avena ...198216662495
the hydraulic conductivity as a criterion for the membrane integrity of protoplasts fused by an electric field pulse.the hydraulic conductivity of the membrane, lp, of fused plant protoplasts was measured and compared to that for unfused cells, in order to identify possible changes in membrane properties resulting from the fusion process. fusion was achieved by an electric field pulse which induced breakdown in the membranes of protoplasts in close contact. close membrane contact was established by dielectrophoresis. in some experiments pronase was added during field application; pronase stabilizes protoplasts ...198224271667
correlation between the lipid composition and the responsiveness of avena sativa stem segments to gibberellic acid.the lipid composition of avena sativa stem segments was manipulated using basf 13-338 (formerly sandoz 9785) and growth temperature, in order to establish whether there were correlations between responsiveness of the tissue to gibberellic acid (ga(3)) and the presence, before hormone treatment, of specific lipid components. high correlations were obtained between ga(3)-induced growth and total phospholipid, individual phospholipids, and fatty acids (except for linolenic acid), total saturated fa ...198216662703
phytochrome-controlled extension growth of avena sativa l. seedlings : ii. fluence rate response relationships and action spectra of mesocotyl and coleoptile responses.fluence rate response curves for light-induced inhibition of mesocotyl growth and promotion of coleoptile growth in etiolated avena sativa l. (cv. victory) were developed. the irradiation time was 24 h. fluence rates between 10(-6) and 10(5) nmol m(-2)s(-1) and 30 wavelengths between 563 and 1,093 nm were used. the main conclusions are as follows: 1. both organs exhibit a low fluence rate response as well as a high fluence rate response. 2. the mesocotyl response is more sensitive to light than ...198224276066
phytochrome-controlled extension growth of avena sativa l. seedlings : i. kinetic characterization of mesocotyl, coleoptile, and leaf responses.the effects of continuous red and far-red light and of brief light pulses on the growth kinetics of the mesocotyl, coleoptile, and primary leaf of intact oat (avena sativa l.) seedlings were investigated. mesocotyl lengthening is strongly inhibited, even by very small amounts of pfr, the far-red light absorbing form of phytochrome (e.g., by [pfr]≈0.1% of total phytochrome, established by a 756-nm light pulse). coleoptile growth is at first promoted by pfr, but apparently inhibited later. this in ...198224276065
regulation of h excretion : role of protein released by osmotic shock.when the protoplasts of peeled oat leaf segments (avena sativa l.) expand after a brief plasmolysis (osmotic shock), fusicoccin-enhanced h(+) excretion is reduced and protein is released to the rehydration medium. this shock protein seems to arise from the cell surface, not from the interior of leaky cells or from broken cells, because (a) the protein differs quantitatively and qualitatively from protein of cell homogenates as determined by sodium dodecyl sulfate-polyacrylamide gel electrophores ...198216662324
regulation of h excretion : effects of osmotic shock.osmotic shock, a 15-minute plasmolysis followed by a 15-minute rehydration in the cold, is a nondestructive technique which inhibits fusicoccin-stimulated h(+) excretion from oat mesophyll cells (avena sativa l.). osmotic shock also causes a loss of intracellular solutes and stimulates h(+) uptake, but osmoregulation can still occur, and enhanced h(+) uptake is observed only at low external ph. it is concluded that osmotic shock interferes directly with the excretion of h(+) rather than affectin ...198216662323
adenylate levels, energy charge, and phosphorylation potential during dark-light and light-dark transition in chloroplasts, mitochondria, and cytosol of mesophyll protoplasts from avena sativa l.the compartmentation of cellular energy relations during dark-light and light-dark transitions was studied by means of a newly developed technique to fractionate oat (avena sativa l., var. arnold) mesophyll protoplasts. using an improved microgradient system with hydrophobic and hydrophilic layers of increasing density, a pure plastid pellet (up to 90% of total chloroplasts) could be separated from an interphase of only slightly contaminated mitochondria (70 to 80% of total mitochondria), and a ...198216662227
interaction of nitroxide spin labels with chloroplasts.chloroplasts isolated from oats eliminated the electron spin resonance (esr) signals from spin labels in white light and partially restored them in far-red light. only the white light-mediated reaction was blocked by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (dcmu). in contrast, oat (avena sativa l. cv. garry and park) leaf mesophyll protoplasts oxidized the spin labels in both white and far-red light, with and without dcmu. light had no obvious effect on spin label motion within chloroplast membr ...198216662554
localization of spin labels in oat leaf protoplasts.an assay based on light-mediated oxidation was used to determine whether specific spin labels were partitioned throughout the protoplast or retained in the plasmalemma of avena sativa l. cv. garry and park. many classes of spin label were tested, including phospholipids, fatty acid, fatty acid methyl ester, maleimide, iodoacetamide, short chain hydrocarbon, androstane, 2,2,6,6-tetramethyl-4-aminopiperidinooxyl (tempamine) and 2,2,6,6-tetramethylpiperidinooxyl (tempo). all except the phosphotidyl ...198216662553
cell-free synthesis of phytochrome apoprotein.a single polypeptide is immunospecifically precipitated by monospecific antiphytochrome from the total translation products of both wheat-germ and rabbit-reticulocyte cell-free protein synthesizing systems programmed with oat (avena sativa l.) poly(a) rna. the mobility of this polypeptide is slightly lower on sodium dodecyl sulfate (sds) polyacrylamide gel electrophoresis than that of immunoaffinity-purified, 118 kdalton phytochrome and corresponds to an apparent molecular weight of 124 kdalton. ...198224271769
inhibition of elongation growth by two sesquiterpene lactones isolated from helianthus annuus l. : possible molecular mechanism.two sesquiterpene lactones belonging to the germacranolides were isolated from the leaves and stems of helianthus annuus l. their formation in the plant is light-dependent. both sesquiterpene lactones (sl) strongly inhibit indole-3-acetic acid (iaa)-induced elongation growth of avena sativa l. coleoptile segments and helianthus annuus l. hypocotyl segments. both sl do not, however, inhibit acid-induced growth nor growth triggered by fusicoccin at all. in the presence of dithiothreitol (dtt), the ...198224272656
incorporation of [4-(14)c] cholesterol into steryl derivatives and saponins of oat (avena sativa l.) plants.sterols from both green and etiolated oat plants (avena sativa) contain sitosterol, stigmasterol, cholesterol, δ(7)-stigmastenol, δ(7)-cholestenol and campesterol. in the saponin fraction avenacosides a and b and 26-desgluco-avenacosides a and b were detected. etiolated plants incorporated [4-(14)c] cholesterol into steryl derivatives (esters, glycosides and acylated glycosides) and also into all of the 4 saponins. [4-(14)c] sitosterol, however, is incorporated only into steryl derivatives, but ...198224257768
pigment-protein complexes of illuminated etiolated leaves.photoconversion of protochlorophyllide in etiolated leaves of avena sativa l., var. pennal or peniarth and phaseolus vulgare l., var. ;the prince' results in the sequential appearance of spectrally distinct chlorophyllide complexes (chlide 678, 684, and 672). this paper reports on the generation of similar forms in vitro, under controlled conditions, using well characterized etioplast membranes enriched in the enzyme protochlorophyllide reductase. excess nadp(+) and nadph stabilize complexes rel ...198216662606
evidence for a cl-stimulated mgatpase proton pump in oat root membranes.the possibility that plant membrane-bound mgatpases may act as electrogenic proton pumps has been investigated. using an oat (avena sativa l. cv. victory) root membrane preparation which is partially enriched in tightly sealed vesicles, we have shown that mgatp stimulates the uptake of the membrane-permeable anion [(14)c]scn(-) by the vesicles; this indicates that an electrical potential (interior positive) is generated across the membrane. both cl(-) ions and the proton ionophore trifluorometho ...198216662299
energy coupling in h-amino acid cotransport : atp dependence of the spontaneous electrical repolarization of the cell membranes in oat coleoptiles.experiments were undertaken in order to test the mechanism of energy coupling for amino acid uptake proposed in the cotransport hypothesis. according to the hypothesis an electrochemical potential difference in h(+) is established by active h(+) extrusion. that potential difference then drives the cotransport of h(+) and amino acids into the cells. application of amino acids to oat (avena sativa var. victory) coleoptiles induced transient depolarizations of the cell membrane electrical potential ...198216662266
production and purification of monoclonal antibodies to pisum and avena phytochrome.at least nine monoclonal antibodies against phytochrome from pisum sativum l. and 20 against phytochrome from avena sativa l. have been obtained from mouse hybridomas that were produced by fusion of spleen cells with sp 2/o-ag14 myeloma cells. hybridomas were selected and cloned in a single step by plating on a semisolid methylcellulose medium. eight antibodies to pisum and one to avena phytochrome were immunopurified from hybridoma medium or ascitic fluid. when necessary, secreted antibodies we ...198324264758
differential uptake of mercury vapor by gramineous c(3) and c(4) plants.the uptake of mercury vapor by six gramineous plant species was compared under uniform conditions using a whole-plant chamber and (203)hg-labeled mercury at a low atmospheric concentration. mean hg uptake by leaves of the c(3) species oats (avena sativa), barley (hordeum vulgare), and wheat (triticum aestivum) was 5 times greater than that by leaves of the c(4) species corn (zea mays), sorghum (sorghum bicolor), and crabgrass (digitaria sanguinalis). although there was a difference in resistance ...198316663117
phytochrome-mediated cellular photomorphogenesis.red light-induced cell elongation and division in intact, etiolated oat (avena sativa cv lodi) seedlings have been assessed. the middle of coleoptile was especially responsive in the very low fluence range whereas the region immediately below the coleoptile tip and the two regions just above the coleoptilar node were more responsive than the entire organ in the low fluence range. these responses in the coleoptile are both the result of an increase in cell elongation. coleoptile cell division is ...198316663071
relation between respiration and senescence in oat leaves.the respiration of excised oat (avena sativa cv victory) leaves and their sensitivity to inhibitors was followed during senescence under varied conditions. the respiration rate, which in controls reaches its peak on the third day in darkness, is lowered at the time of fastest loss of chlorophyll (as reported earlier) by seven unrelated reagents that all delay dark senescence. when senescence is delayed by white light or by cytokinins, the respiratory rise is correspondingly delayed. kinetin and ...198316663039
structure-function studies on phytochrome. preliminary characterization of highly purified phytochrome from avena sativa enriched in the 124-kilodalton species.a new protocol for the purification of phytochrome from etiolated avena sativa l. seedlings in 15-25% yield is described. this preparation exhibits molecular properties dissimilar to those previously reported from oats. phytochrome prepared by this method contains a dominant species having a mr = 124,000 (70% of total) on sodium dodecyl sulfate-polyacrylamide gels, in addition to a chromoprotein species with mr = 118,000 (30%). a blocked nh2 terminus is indicated by amino acid sequencing of the ...19836885811
a study of homoeologous relationships in the cultivated oat avena sativa (2n=6x=42).the homoeologous relationship of the chromosomes of the allopolyploid species avena sativa has been demonstrated by studies of nullisomic-tetrasomic compensation. the effects of the deletion of chromosome vi was partially compensated for by a tetrasomic dose of chromosome xiii, both at the gametic and zygotic level. the data confirm the genetic similarities of the homoeologues, which are attributable to their evolutionary derivation from a common chromosome.198324263931
a report on the consumption, composition and nutritional adequacy of a mixture of lush green perennial ryegrass (lolium perenne) and cocksfoot (dactylis glomerata) fed ad libitum to thoroughbred mares.non-pregnant thoroughbred mares were stabled and subjected to 2 trials, each 24 h in duration, to establish their total consumption of a mixture of freshly cut, lush green perennial ryegrass (lolium perenne) and cocksfoot (dactylis glomerata) in approximately equal proportions; and to compare the total intake of crude protein, calcium, phosphorus and mass of the grass mixture on a dry matter basis with their daily nutritional requirements. the body mass of each mare was calculated at the commenc ...19836655653
role of endoplasmic reticulum in biosynthesis of oat globulin precursors.oat (avena sativa l.) groats were labeled with radioactive leucine and salt-soluble proteins were extracted and analyzed. polyacrylamide gel electrophoresis followed by fluorography indicated two radioactive polypeptides with molecular weight 58 to 62 kilodaltons which were similar in size to unreduced globulin alpha-beta dimers. the role of endoplasmic reticulum in the synthesis of these globulin polypeptides was investigated by in vivo and in vitro protein synthesis studies. labeled tissue was ...198316663349
separation of two types of electrogenic h-pumping atpases from oat roots.microsomal vesicles of oat roots (avena sativa var lang) were separated with a linear dextran (0.5-10%, w/w) or sucrose (25-45%, w/w) gradient to determine the types and membrane identity of proton-pumping atpases associated with plant membranes. atpase activity stimulated by the h(+)/k(+) exchange ionophore nigericin exhibited two peaks of activity on a linear dextran gradient. atpase activities or atp-generated membrane potential (inside positive), monitored by scn(-) distribution, included a ...198316663344
phytochrome quantitation in crude extracts of avena by enzyme-linked immunosorbent assay with monoclonal antibodies.an enzyme-linked immunosorbent assay (elisa), which uses both rabbit polyclonal and mouse monoclonal antibodies to phytochrome, has been adapted for quantitation of phytochrome in crude plant extracts. the assay has a detection limit of about 100 pg phytochrome (<1 fmol of monomer) and can be completed within 10 h. nonspecific interference by crude plant extracts was detected and corrected for. quantitation of phytochrome in crude extracts of etiolated oat (avena sativa l.) seedlings by elisa ga ...198324258330
role of o(2) and mitochondrial respiration in a photosynthetic stimulation of oat protoplast acidification of a surrounding medium.some photosynthetically stimulated acidification of the medium by oat (avena sativa l. cv garry) leaf protoplasts required respiration. the requisite respiration (a) had a low apparent affinity for o(2), (b) was blocked by cyanide plus salicylhydroxamic acid, (c) characterized protoplasts and mitochondria isolated from protoplasts, (d) could be induced in leaf segments, and (e) appeared to result from an inhibition of mitochondrial respiration that included the cytochrome pathway.carbon monoxide ...198316663006
stereospecific analysis of triglycerides of glycine max, glycine soya, avena sativa and avena sterilis strains.a rapid method for the stereospecific analysis of triglycerides based on enzymatic hydrolysis on thin layer plates was applied to a number of glycine max, glycine soya, avena sativa and avena sterilis strains. the percentage of each fatty acid on the sn-1-, sn-2- and sn-3-positions was linearly related to the total percentage of the fatty acid in the triglyceride. large deviations from the common triglyceride pattern were not found.19836686643
compartmentation of labeled fixation products in intact mesophyll protoplasts from avena sativa l. after in-situ inhibition of the chloroplast phosphate translocator.leaf mesophyll protoplasts of oat (avena sativa l.) were allowed to fix (14)c-labeled bicarbonate in the absence or presence of pyridoxal phosphate (plp), a specific inhibitor of the phosphate translocator of the inner envelope membrane of chloroplasts. the incubation was terminated by a method of rapid integrated protoplast homogenization and fractionation, and compartmented levels of label contained in sugars, phosphate esters, amino acids and organic acids were determined. the results show th ...198324258228
rapid response of the plasma-membrane potential in oat coleoptiles to auxin and other weak acids.we have compared the effects of the auxin, indole-3-acetic acid (iaa) with that of other weak acids on the plasma-membrane potential of oat (avena sativa l.) coleoptile cells. cells treated with 1 μm iaa at ph 6 depolarize 20-25 mv in 10-12 min, but they then repolarize, until by 20-25 min their potentials are about 25 mv more negative than the initial value. similar concentrations of benzoic and butyric acids cause the initial depolarization, but not the subsequent hyperpolarization. the hyperp ...198324258173
interaction of indoleacetic acid and gibberellic acid in the short-term growth kinetics of oat stem segments.gibberellins and auxins are the only hormones known that promote growth in oat (avena sativa) stem segments, but when applied together, indoleacetic acid inhibits gibberellic acid-induced growth appreciably. this study shows that in addition to this inhibitory role, indoleacetic acid shortens the response time of the tissue to gibberellic acid.198316663259
light-induced breakdown of nadph-protochlorophyllide oxidoreductase in vitro.light-induced loss of the enzyme protochlorophyllide reductase (ec 1.6.99.1.), already described as a characteristic of whole plants, has now been demonstrated in vitro using etioplast membrane preparations of avena sativa l. var peniarth and secale cereale l. var rheidol. some evidence is presented, based upon temperature, ph, and inhibitor sensitivity of the process, that loss of enzyme may be the result of proteolysis. the light-induced process can, in vitro, be largely prevented by addition ...198316662967
oat seed globulin: subunit characterization and demonstration of its synthesis as a precursor.the predominant storage protein of oat (avena sativa l.) seeds is a saline-soluble globulin with a mol wt of 320,000 which is composed of six large (m(r) = 35,000 to 40,000) and six small (m(r) = 20,000 to 25,000) subunits. experiments were conducted to further describe the subunit polypeptides and to identify the initial translation products of globulin mrnas. approximately 20 large subunits and 10 small subunits were resolved by two-dimensional gel analysis. the large and small subunits had ac ...198316662952
light-stimulated changes in the acidity of suspensions of oat protoplasts: dependence upon photosynthesis.light induced an alkalinization and stimulated a subsequent acidification of the medium surrounding oat (avena sativa l. cv garry) leaf protoplasts. blue light was less effective than would be predicted from photosynthetic action spectra. nonetheless, 3-(3,4-dichlorophenyl)-1,1-dimethylurea prevented alkalinization and reduced acidification to the dark rate for protoplast suspensions exposed to all light regimes tested.alkalinization increased in parallel with initial rates of o(2) evolution as ...198316663005
cellular and subcellular localization of calcium in gravistimulated oat coleoptiles and its possible significance in the establishment of tropic curvature.light-and electron-microscopic studies of the distribution of calcium in gravitropically responding oat (avena sativa l. cv. "garry") coleoptiles are described. a modification of the antimonate precipitation procedure was used to localize tissue calcium in situ. an accumulation of ca in the upper halves of horizontal, gravistimulated coleoptiles is seen within 10 min of stimulus onset. a pronounced redistribution of ca to the upper side occurs within 30 min; although the localization of this cat ...198324264412
analysis of phytochrome kinetics in light-grown avena sativa l. seedlings.the phytochrome content, the rate of phytochrome accumulation after a light/dark transition and the rate of phytochrome destruction after a 1.5 d reaccumulation period in darkness were measured in light grown avena sativa l. seedlings. the results using spectrophotometrical methods (norflurazon treated seedlings) and the radio-immunoassay (ria) (green seedlings) were almost identical. the rate of phytochrome synthesis was analysed by measuring the activity of poly(a(+))-rna coding for the phytoc ...198324264335
aminotransfer from alanine and glutamate to glycine and serine during photorespiration in oat leaves.(15)n-labeled glutamate and alanine were used to examine the photorespiratory nitrogen metabolism in oat (avena sativa l.) leaf slices. glutamate and alanine supply amino groups for glycine formation during photorespiration. the nitrogen flux from alanine to glycine was estimated to be 3 times higher than that from glutamate. it is concluded from these results that alanine is a direct and important amino donor for photorespiratory glycine formation in oat leaves. the (15)n labeling of serine was ...198316662936
differential changes in the amount of protein complexes in the chloroplast membrane during senescence of oat and bean leaves.antibodies against the individual subunits of protein complexes in the chloroplast membranes were used to follow the amounts of these polypeptides during foliar senescence. no change was found in the amount of polypeptides of photosystem i reaction center and the chloroplast coupling factor during senescence of oat (avena sativa l.) and bean (phaseolus vulgaris l.) leaves. a significant decrease in the amount of the different components of the cytochrome b(6)-f complex was detected. this change ...198316663247
differences in the physical properties of native and partially degraded phytochrome as probed by their differential sensitivity to permanganate oxidation.the differential sensitivities to permanganate oxidation of the red and far-red forms of native phytochrome from avena sativa l. cv mulaga (isolated as pfr from red-irradiated tissue) and of partially degraded phytochrome (isolated as pr from nonirradiated tissue) were determined. the far-red absorbing form of partially degraded phytochrome was 5 times more sensitive than its red-absorbing form, while both the far-red and red forms of native phytochrome exhibited identical sensitivity. the prese ...198316663241
translocation and metabolism of endosperm-applied [2-c] indoleacetic acid in etiolated avena sativa l. seedlings.the role of free indole-3-acetic acid (iaa) in the endosperm of avena sativa l. seedlings was investigated to determine its contribution to free iaa in the shoot. [2-(14)c]iaa was injected into the endosperm of darkgrown seedlings and the transport and metabolism of the [(14)c]-labeled compounds determined. it was concluded that translocation of free iaa directly from the endosperm is probably not a significant source of free iaa in the shoot, mainly because even small amounts of [(14)c]iaa intr ...198316663214
putrescine and acid stress : induction of arginine decarboxylase activity and putrescine accumulation by low ph.incubation of peeled oat avena sativa l. var victory leaf segments on media of ph 5.0 or below leads to a rapid and massive increase in the titer of putrescine while incubation at ph values above 5.0 causes little or no change. the low ph effect is independent of the buffer system employed. putrescine levels rise within 3 hours and reach their peak 8 to 9 hours after acidification. at this time, putrescine titer is eight times greater at ph 3.5 than at 6.0. none of the other polyamines shows a r ...198316662904
anion-sensitive, h-pumping atpase in membrane vesicles from oat roots.h(+)-pumping atpases were detected in microsomal vesicles of oat (avena sativa l. var lang) roots using [(14)c]methylamine distribution or quinacrine fluorescent quenching. methylamine (mea) accumulation into vesicles and quinacrine quench were specifically dependent on mg,atp. both activities reflected formation of a proton gradient (deltaph) (acid inside) as carbonyl cyanide m-chlorophenylhydrazone, nigericin (in the presence of k(+)), or gramicidin decreased mea uptake or increased quinacrine ...198316662875
isolation and characterization of oat aleurone and starchy endosperm protein bodies.to compare oat (avena sativa l. cv froker) aleurone protein bodies with those of the starchy endosperm, methods were developed to isolate these tissues from mature seeds. aleurone protoplasts were prepared by enzymic digestion and filtration of groat (caryopsis) slices, and starchy endosperm tissue was separated from the aleurone layer by squeezing slices of imbibed groats followed by filtration. protein bodies were isolated from each tissue by sucrose density gradient centrifugation. ultrastruc ...198316662859
metabolism of oat leaves during senescence : vii. the interaction of carbon dioxide and other atmospheric gases with light in controlling chlorophyll loss and senescence.in air largely freed from co(2), senescence of isolated oat (avena sativa cv victory) seedling leaves is no longer prevented by white light; instead, the leaves lose both chlorophyll and protein as rapidly as in the dark. senescence in light is also accelerated in pure o(2), but it is greatly delayed in n(2); 100% n(2) preserves both protein and chlorophyll in light and in darkness. in light in air, most of the compounds tested that had previously been found to delay or inhibit senescence in dar ...198316662800
isolation and characterization of oat globulin messenger rna.when polyadenylated rna, isolated from membrane-bound polysomes extracted from developing oat (avena sativa l.) seeds, was translated in vitro in the rabbit reticulocyte system, two polypeptides of about 58 and 60 kilodaltons were immunoprecipitated by anti-oat globulin antibody. no electrophoretic bands corresponding to the 40 and 20 kilodalton polypeptides of oat globulin were present. however, when in vivo labeled extracts were immunoprecipitated with anti-oat globulin antibody, three groups ...198316663046
rotation of cells and ion exchange beads in the mhz-frequency range.whereas human red blood cells and protoplasts of leaves of avena sativa show rotation only at discrete frequencies in the khz-range of a linear alternating electric field, rotation of these cells is observed at practically every frequency in the mhz range (15 to 200 mhz). the cell rotation in the mhz-range can be explained in terms of field induced polarisation and orientation of permanent dipoles within the membrane and the cell. this interpretation is supported by the finding that chelex beads ...19836880341
glycerate kinase from leaves of c3 plants.d-glycerate-3-kinase (ec 2.7.1.31) in six c3 species, including dicots (pisum sativum, spinacea oleracea, antirrhinum majus) and monocots (secale cereale, hordeum vulgare, avena sativa), ranged in activity from 44 to 353 mumol x mg chl-1 x h-1. studies with protoplast extracts of these species indicate that the enzyme is localized in the chloroplasts. glycerate kinase was partially purified from secale (rye, 288-fold) and pisum (pea, 252-fold) chloroplasts by deae-cellulose chromatography, sucro ...19836307152
a seed storage protein with possible self-affinity through lectin-like binding.the primary storage protein of oat (avena sativa l.) seeds, globulin, was shown to have a specific carbohydrate-binding activity. the globulin was capable of hemagglutinating rabbit red blood cells and this hemagglutination was inhibited by the beta-glucan, laminarin, as well as by carbohydrate which had been cleaved from the native globulin. globulin with carbohydrate-binding activity was isolated from cell wall preparations and from defatted flour. the lectin activity apparently resides in the ...198416663480
characterization of oat calmodulin and radioimmunoassay of its subcellular distribution.a protein identifiable as calmodulin has been isolated from oat (avena sativa, var garry) tissues. this protein is relatively heat stable, binds to hydrophobic gels, and phenothiazines in a calcium-dependent fashion, and binds to antibody to rat testes calmodulin. based on its migration on sodium dodecyl sulfate-polyacrylamide gels, ultraviolet absorption spectrum, and amino acid composition, oat calmodulin is essentially identical to calmodulin isolated from other higher plants. radioimmunoassa ...198416663631
characterization by enzyme-linked immunosorbent assay of monoclonal antibodies to pisum and avena phytochrome.nine monoclonal antibodies to pea (pisum sativum l.) and 16 to oat (avena sativa l.) phytochrome are characterized by enzyme-linked immunosorbent assay against phytochrome from six different sources: pea, zucchini (cucurbita pepo l.), lettuce (lactuca sativa l.), oat, rye (secale cereale l.), and barley (hordeum vulgare l.). all antibodies were raised against phytochrome with a monomer size near 120,000 daltons. nevertheless, none of them discriminated qualitatively between 118/114-kilodalton oa ...198416663365
monoclonal antibodies to three separate domains on 124 kilodalton phytochrome from avena.forty-six monoclonal antibodies have been prepared against 124 kilodalton phytochrome from avena sativa cv garry. clones grown in mice have yielded ascites fluids with antibodies which bind to three distinct regions of the molecule, as visualized by immunoblot analysis of proteolytically produced peptides of the protein. one antibody group (type 1) recognizes an antigenic domain(s) that lies within 6 kilodaltons of the amino terminus of the molecule, a region critical to correct protein-chromoph ...198416663895
anion-sensitive, h-pumping atpase of oat roots : direct effects of cl, no(3), and a disulfonic stilbene.to understand the mechanism and molecular properties of the tonoplast-type h(+)-translocating atpase, we have studied the effect of cl(-), no(3) (-), and 4,4'-diisothiocyano-2,2'-stilbene disulfonic acid (dids) on the activity of the electrogenic h(+)-atpase associated with low-density microsomal vesicles from oat roots (avena sativa cv lang). the h(+)-pumping atpase generates a membrane potential (deltapsi) and a ph gradient (deltaph) that make up two interconvertible components of the proton e ...198416663870
redox activity at the surface of oat root cells.electron transport activity at the cell surface of intact oat seedlings (avena sativa l. cv garry) was examined by measuring the oxidation and/or reduction of agents in the medium bathing the roots. oxidation of nadh with or without added electron acceptors and reduction of ferricyanide by an endogenous electron donor were detected. the activities appear to be due to electron transfer at, or across, the plasma membrane and not due to reagent uptake or leakage of oxidants or reductants. nadh-ferr ...198416663850
physiological control of arginine decarboxylase activity in k-deficient oat shoots.the effect of k-deficiency on the putrescine biosynthetic enzyme, arginine decarboxylase (adc), was investigated by growing oat (avena sativa l. var victory) plants on a low-k, but otherwise complete nutrient medium in washed quartz sand for up to 18 days. enzyme activity rose as the concentration of kcl was dropped to 0.6 millimolar or below. however, growth was not inhibited significantly at 0.6 millimolar kcl. adc activity increased in the whole shoot of k-deficient oats throughout the period ...198416663842
a quantitative simulation model for h-amino acid cotransport to interpret the effects of amino acids on membrane potential and extracellular ph.the h(+) cotransport of neutral and acidic amino acids induces transient depolarizations of oat coleoptile (avena sativa l., var victory) plasma membranes. the depolarizations, which are completed within 1 or 2 minutes, are followed by repolarizations that are nearly completed within another 2 or 3 minutes. cysteine induced a two-phased alkalinization of the tissue free space during the electrical changes. the first phase was a rapid, linear increase in ph that coincided with the depolarization; ...198416663928
the instron technique as a measure of immediate-past wall extensibility.the relationship between the plastic-extensibility values (pex) obtained in the instron technique and the growth parameter, wall extensibility (φ) has been evaluated for avena sativa l. coleoptile cell walls. the possibility that pex is proportional to the growth rate rather than to φ has been eliminated by showing that turgor-driven changes in the growth rate do not cause comparable changes in pex. for avena coleoptiles, pex appears to be a measure of the average φ over the previous 60-90 min r ...198424258778
glyoxylate transamination in intact leaf peroxisomes.intact spinach (spinacia oleracea l.) leaf peroxisomes were supplied with glycolate and one to three of the amino acids serine, glutamate, and alanine, and the amount of the respective alpha-keto acids formed in glyoxylate transamination was assayed. at 1 millimolar glycolate and 1 millimolar each of the three amino acids in combination, the transamination reaction reached saturation; reduction of either glycolate or amino acid concentration decreased the activity. the relative serine, glutamate ...198416663603
characterization of oat vicilin-like polypeptides.the 7s and 3s globulin fractions were extracted and characterized from avena sativa l. seeds which showed similar solubility characteristics and holoprotein size to those of the vicilin fraction in legumes. these holoproteins were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectrofocussing, and two-dimensional electrophoresis. among the components of the oat reserve globulins, the 7s fraction was capable of binding to concanavalin a-sepharose, thus indicating ...198416663577
purification, characterization, and kinetic mechanism of s-adenosyl-l-methionine: vitexin 2"-o-rhamnoside 7-o-methyltransferase of avena sativa l.an o-methyltransferase catalyzing the transfer of the methyl group of s-adenosyl-l-methionine to the a-ring 7-hydroxyl group of vitexin 2"-o-rhamnoside has been isolated from oat primary leaves and purified 180-fold by protein fractionation with (nh4)2so4 and chromatography on deae-cellulose and s-adenosyl-l-homocysteine-sepharose. km values for s-adenosyl-l-methionine and the flavonoid substrate were 1.6 microm and 15 microm, respectively. the lack of methyltransfer to biosynthetic intermediate ...19846705789
discrimination between the red- and far-red-absorbing forms of phytochrome from avena sativa l. by monoclonal antibodies.a set of rat monoclonal antibodies (arc mac 48 to 52 and 54 to 56), raised to phytochrome from dark-grown seedlings of avena sativa l. was tested for the ability to discriminate between the red-absorbing (pr) and far-red-absorbing (pfr) forms of phytochrome by indirect enzyme-linked immunosorbent assay. mac 50 bound more strongly to pfr and mac 49 and 52 showed preferential binding to pr from extracts of dark-grown avena seedlings; mac 50 also bound more strongly to pfr from brushite-purified ph ...198424258587
quantitation of oat globulin by radioimmunoassay.a radioimmunoassay was used to determine the globulin content of developing oat (avena sativa l. var coker 6622) seeds. the globulin content increased from 0.32 to 2.37 milligrams per seed from 2 to 21 days post anthesis. the amount of globulin did not increase from 21 to 30 days post anthesis. when the total protein of seeds harvested 21, 24, and 30 days post anthesis was measured by micro-kjeldahl analysis, it was determined to be 3.15 milligrams per seed for each sampling date. when the amoun ...198416663443
auxin concentration/growth relationship for avena coleoptile sections from seedlings grown in complete darkness.a biphasic auxin dose-response curve has been obtained for indole-acetic acid (iaa)-stimulated growth of subapical sections of coleoptiles from totally dark-grown oats (avena sativa l. cv lodi). the curve for growth at 6 h is composed of a log-linear phase and a modified bell-shaped phase separated by a plateau. the curve is log-linear from 0.003 to 0.4 micromolar iaa when sections are incubated in ph 5.9 buffer. the plateau of iaa concentration-neutral growth is seen from 0.4 to 4.0 micromolar ...198416663419
sterols in seeds and leaves of oats (avena sativa l.).in seeds and leaves of oats (avena sativa l.) 12 different sterols (cholesterol, cholstanol, δ(7)-cholestenol, campesterol, campestanol, stigmasterol, lophenol, sitosterol, stigmastanol, δ(5)-avenasterol, δ(7)-avenasterol and δ(7)-stigmastenol) have been identified. the sterol pattern is qualitatively the same, but the relative composition is different in leaves and in seeds. leaves contain mainly sitosterol, stigmasterol, cholesterol and campesterol, but only minor portions of avenasterols. see ...198424253572
intracellular transport and posttranslational cleavage of oat globulin precursors.the synthesis, transport, and posttranslational processing of reserve globulin in avena sativa l. seeds were studied by pulse-chase labeling. developing oat seeds were labeled with radioactive sulfate and tissue homogenates were used for globulin extraction.two globulin precursors (58-62 kilodaltons) were labeled after 1 hour pulse. the alpha and beta globulin subunits appeared between 2 and 10 hours later, while simultaneously the 58 to 62 kilodaltons polypeptides gradually disappeared. this co ...198416663789
determination of compartmented metabolite pools by a combination of rapid fractionation of oat mesophyll protoplasts and enzymic cycling.in vivo pool sizes of a range of metabolites have been determined in subcellular fractions of darkened and illuminated mesophyll protoplasts of avena sativa l. these estimations were made by combining a method of rapid protoplast fractionation with enzymic cycling techniques. results are given for reduced and oxidized pyridine nucleotides, triose phosphates, 3-phosphoglycerate, inorganic phosphate, aspartate, malate, oxaloacetate, glutamate, 2-oxoglutarate, and citrate, from chloroplasts, mitoch ...198416663726
inhibition of gravitropism in oat coleoptiles by the calcium chelator, ethyleneglycol-bis-(beta-aminoethyl ether)-n,n'-tetraacetic acid.a treatment period as brief as 8 h in 10(-3) m egta completely blocks gravitropism in 70-80% of the treated coleoptiles of oats (avena sativa l. cv. garry) without inhibiting growth. only about 10% of the plants perfused in water failed to exhibit gravitropism. subsequent perfusion of egta-treated plants with calcium completely restores gravitropism; post-perfusion with water does not. after perfusion in water for 10 h, gravistimulated oat coleoptile segments show the same asymmetry of 45ca dist ...198411829020
biosynthesis of jasmonic acid by several plant species.six plant species metabolized (18)o-labeled 12-oxo-cis,cis-10,15-phytodienoic acid (12-oxo-pda) to short chain cyclic fatty acids. the plant species were corn (zea mays l.), eggplant (solanum melongena l.), flax (linum usitatissimum l.), oat (avena sativa l.), sunflower (helianthus annuus l.), and wheat (triticum aestivum l.). among the products was jasmonic acid, a natural plant constituent with growth-regulating properties. the pathway is the same as the one recently reported by us for jasmoni ...198416663643
indole-3-acetic acid sensitization of phytochrome-controlled growth of coleoptile sections.addition of 6 mum indole-3-acetic acid (iaa) to incubation buffer increases the sensitivity of coleoptile sections cut from dark-grown avena sativa l. cv. lodi to red light by a factor of 10,000, relative to the response in the absence of added iaa, without changing the maximum amount of light-induced growth. from 0.03 to 4 mum iaa sections show at least a 100-fold increase in sensitivity to red light relative to the response in the absence of added iaa. in this iaa concentration range, the ligh ...198416593476
native phytochrome: immunoblot analysis of relative molecular mass and in-vitro proteolytic degradation for several plant species.the relative molecular mass (mr) of the native phytochrome monomer from etiolated cucurbita pepo l., pisum sativum l., secale cereale l. and zea mays l. seedlings has been determined using immunoblotting to visualize the chromoprotein in crude extracts subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. a single phytochrome band is observed for each plant species when the molecule is extracted under conditions previously demonstrated to inhibit the proteolysis of native avena ...198424258779
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