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[comparison of presence of ascorbic acid and the appearance of ascorbate peroxidase activity in embryos of avena sativa l].avena sativa l. grains are devoid of ascorbic acid (aa) and of oxidative enzymes (aa oxidase and aa peroxidase), while both reducing enzymes (afr reductase and dha reductase) are present. aa biosynthesis in the embryos starts after 12-14 hours of germination and at the same time aa peroxidase activity is detectable. during the following 14 hours the aa peroxidase activity rises up to 28 nmoles/aa oxidated/min/mg/prot. incubation of avena embryos with gl (the last precursor of aa according to the ...19902390226
oat mesophyll protoplasts: their response to various feeder cultures.oat (avena sativa l.) mesophyll protoplasts were recently demonstrated to be capable of dedifferentiation, repeated divisions, and colony formation. since the development of oat mesophyll protoplasts is decisively influenced by the nature of the used feeder culture (species, variety and concentration), we conducted a systematic study of this parameter. generally, graminaceous feeders promoted protoplast proliferation, while dicot species repressed protoplast divisions. the beneficial effect of t ...199024232678
fructan precipitation from a water/ethanol extract of oats and barley.fructan was precipitated from a water and ethanol extract of oat (avena sativa l.) and barley (hordeum vulgare l.). the degree of polymerization and response on a differential refractometer, based on peak area and height, was compared to fructan collected from a lead-based hplc column and to commercially available inulin. statistically significant differences are discussed.199016667347
senescence and stomatal aperture as affected by antibiotics in darkness and light.in leaves of barley (hordeum vulgare), as previously found with oats (avena sativa), a group of six antibiotics that interfere in different ways with the sequence dna --> mrna --> protein all delay senescence in the dark, acting to conserve chlorophyll (chl) and protein and also to open the stomata. among the active compounds is chloramphenicol, which had previously been reported to act only on procaryotes. it is now shown that all these compounds with senescence-delaying action in darkness have ...199016667337
intracellular localisation of phytochrome in oat coleoptiles by electron microscopy : dependence on light pretreatments and the amount of the active, far-red-absorbing form.the intracellular localisation of phytochrome in oat (avena sativa l. cv. garry oat) coleoptiles was analysed by electron microscopy. serial ultrathin sections of resin-embedded material were indirectly immunolabeled with polyclonal antibodies against phytochrome together with a gold-coupled second antibody. the limits of detectability of sequestered areas of phytochrome (saps) were analysed as a function of light pretreatments and amounts of the far-red absorbing form of phytochrome (pfr) estab ...199024202016
solubilization and reconstitution of the oat root vacuolar h/ca exchanger.calcium is sequestered into vacuoles of oat (avena sativa l.) root cells via a h(+)/ca(2+) antiporter, and vesicles derived from the vacuolar membrane (tonoplast) catalyze an uptake of calcium which is dependent on protons (ph gradient [deltaph] dependent). the first step toward purification and identification of the h(+)/ca(2+) antiporter is to solubilize and reconstitute the transport activity in liposomes. the vacuolar h(+)/ca(2+) antiporter was solubilized with octylglucoside in the presence ...199016667279
genomic sequence of a 12s seed storage protein gene from oat (avena sativa l. cv. 'solidor'). 19902326176
free amino acid composition of leaf exudates and phloem sap : a comparative study in oats and barley.comparisons were made between the free amino acid composition in leaf exudates and that in pure phloem sap, using twin samples taken from a single leaf of two oat (avena sativa l.) and three barley (hordeum vulgare l.) varieties. leaf exudate was collected in a 5 mm edta-solution (ph 7.0) from cut leaf blades and phloem sap was obtained through excised aphid (rhopalosiphum padi l.) stylets. fluorescent derivatives of amino acids were obtained using 9-fluorenylmethyl chloroformate and were separa ...199016667250
unusual hepatic parenchymal crystalloid material and biliary microliths in goats.investigation into an outbreak of suspected photosensitivity in boer goats grazing green oats (avena sativa) led to the finding of microscopical parenchymal crystaloid material and biliary microliths in the livers of 3 ewes that were killed for necropsy. neither tribulus terrestris nor panicum spp. occurred on the farm. further investigation resulted in the isolation, from leaf spots on the oat leaves, of the fungus drechslera campanulata, cultures of which have been shown to be highly toxic to ...19892634769
polyamine binding to proteins in oat and petunia protoplasts.previous work (a apelbaum et al. [1988] plant physiol 88: 996-998) has demonstrated binding of labeled spermidine (spd) to a developmentally regulated 18 kilodalton protein in tobacco tissue cultures derived from thin surface layer explants. to assess the general importance of such spd-protein complexes, we attempted bulk isolation from protoplasts of petunia and oat (avena sativa). in petunia, as in tobacco, fed radioactive spd is bound to protein, but in oat, spd is first converted to 1,3,-d ...198911537462
suitability of small grains as hosts of meloidogyne species.seven cultivars of wheat, five of oat, one of rye, and four of barley were tested as hosts for meloidogyne incognita, m. javanica, or m. arenaria under greenhouse conditions where soil temperature ranged from 21 to 34 c. reproduction rates of all nematode species were high on all cultivars, except m. javanica and m. arenaria on 'brooks' and 'florida 501' oat. meloidogyne incognita and m. javanica produced more eggs on roots of 'rutgers' tomato than on cultivars of wheat, oat, rye, or barley.198919287666
revision of the theory of phototropism in plants: a new interpretation of a classical experiment.went's classical experiment on the diffusion of auxin activity from unilaterally illuminated oat coleoptile tips (went 1928), was repeated as precisely as possible. in agreement with went's data with theavena curvature assay, the agar blocks from the illuminated side of oat (avena sativa l. cv. victory) coleoptile tips had, on an average, 38% of the auxin activity of those from the shaded side. however, determination of the absolute amounts of indole-3-acetic acid (iaa) in the agar blocks, using ...198924213051
characterization of a polyphosphoinositide phospholipase c from the plasma membrane of avena sativa.a phosphoinositide-specific phospholipase c activity was identified in oat root (avena sativa, cv victory) plasma membranes purified by separation in an aqueous two-phase polymer system. the enzyme is highly active toward inositol phospholipids but only minimally active toward phosphatidylethanolamine and phosphatidylcholine. activity approaches maximal levels at 200 micromolar phosphatidylinositol 4-phosphate (pip) and is highly dependent on calcium; it is inhibited by 1 millimolar egta and is ...198916667176
diclofop-methyl increases the proton permeability of isolated oat-root tonoplast.diclofop-methyl (methyl ester of 2-[4-(2',4'-dichlorophenoxy)phenoxy]propionate; 100 micromolar) and diclofop (100 micromolar) inhibited both atp- and ppi-dependent formation of h(+) gradients by tonoplast vesicles isolated from oat (avena sativa l., cv dal) roots. diclofop-methyl (1 micromolar) significantly reduced the steady-state h(+) gradient generated in the presence of atp. the ester (diclofop-methyl) was more inhibitory than the free acid (diclofop) at ph 7.4, but this relative activity ...198916667096
analysis of avenin proteins and the expression of their mrnas in developing oat seeds.we have isolated and characterized cdna clones encoding avenins, the prolamine storage proteins of oat seeds. sequence analysis shows that avenins are a related group of polypeptides and that their mrnas differ from each other by point mutations and small insertions and deletions. avenin proteins have structural homology to the alpha/beta-gliadins and gamma-gliadins of wheat, the b-hordeins of barley, and the gamma-secalins of rye. hybridization analysis of dna from various diploid, tetraploid, ...19892535531
in vitro selection for 2,4-d tolerance in red clover.in vitro, selection is a viable method of selecting herbicide-tolerant crops. this research was to evaluate in vitro selection techniques for enhancing 2,4-d [(2,4-dichlorophenoxy) acetic acid] tolerance in red clover (trifolium pratense l.). in vivo and in vitro responses to 2,4-d of eight diverse red clover populations were correlated (r=0.77), justifying in vitro selection for 2,4-d tolerance. suspension cultures of a red clover genotype capable of regeneration were plated onto agar-based nut ...198924227154
selective delipidation of the plasma membrane by surfactants : enrichment of sterols and activation of atpase.the influence of plasma membrane lipid components on the activity of the h(+)-atpase has been studied by determining the effect of surfactants on membrane lipids and atpase activity of oat (avena sativa l.) root plasma membrane vesicles purified by a two-phase partitioning procedure. triton x-100, at 25 to 1 (weight/weight) triton to plasma membrane protein, an amount that causes maximal activation of the atpase in the atpase assay, extracted 59% of the membrane protein but did not solubilize th ...198916666960
beta-d-glucan antibodies inhibit auxin-induced cell elongation and changes in the cell wall of zea coleoptile segments.antiserum was raised against the avena sativa l. caryopsis beta-d-glucan fraction with an average molecular weight of 1.5 x 10(4). polyclonal antibodies recovered from the serum after protein a-sepharose column chromatography precipitated when cross-reacted with high molecular weight (1-->3), (1-->4)-beta-d-glucans. these antibodies were effective in suppression of cell wall autohydrolytic reactions and auxin-induced decreases in noncellulosic glucose content of the cell wall of maize (zea mays ...198916666935
intracellular protein phosphorylation in oat (avena sativa l.) protoplasts by phytochrome action. 1. measurement of action spectra for the protein phosphorylation.the effects of red light and wavelength dependency of the protein phosphorylation in oat protoplasts were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography. red light (660 nm) irradiation of the protoplasts increased the phosphorylation of 15 different proteins, and the phosphorylation of 2 proteins (27 kda, 32 kda) out of 15 were observed to be dependent on the wavelength of the irradiating light. the phosphorylation densities of these two proteins in ...19892751674
lysophosphatidylcholine stimulates atp dependent proton accumulation in isolated oat root plasma membrane vesicles.lysophosphatidylcholine at concentrations of 30 micromolar stimulated the rate of mgatp-dependent h(+)-accumulation in oat (avena sativa l. cv rhiannon) root plasma membrane vesicles about 85% while the passive permeability of h(+) was unchanged. activation was dependent on chain length, degree of saturation, and head group of the lysophospholipid. a h(+)-atpase assay was developed that allowed the simultaneous measurement of proton pumping and atpase activity in the same sample. atp hydrolysis ...198916666844
a wheat alpha-amy2 promoter is regulated by gibberellin in transformed oat aleurone protoplasts.gibberellin (ga(3))-responsive aleurone protoplasts isolated from avena sativa have been successfully used as a transient expression system to analyse promoter fusions between the wheat alpha-amylase gene alpha-amy2/54 and the reporter gene gus. following peg-mediated uptake of plasmid dna, transient expression directed by the alpha-amy2/54 promoter was found to be regulated in the same way as the endogenous oat alpha-amylase genes. expression was thus dependent on the inclusion of ga(3) in the ...198916453890
immunolocalization of avenin and globulin storage proteins in developing endosperm of avena sativa l.the seed storage proteins of oats (avena sativa l.) are synthesized and assembled into vacuolar protein bodies in developing endosperm tissue. we used double-label immunolocalization to study the distribution of these proteins within protein bodies of the starchy endosperm. when sections of developing oat endosperm sampled 8 d after anthesis were stained with uranyl acetate and lead citrate, the vacuolar protein bodies consisted of light-staining regions which were usually surrounded by a darker ...198924212898
characterization of a protein-kinase activity associated with phytochrome from etiolated oat (avena sativa l.) seedlings.a protein-kinase activity which is co-purified with phytochrome from etiolated oat seedlings was investigated in some detail. whereas phytochrome was always phosphorylated in solution (together with some contaminating protein bands), radioactive phosphate was not found in the phytochrome band after native gel electrophoresis and incubation of the entire gel with labeled atp. since protein kinases are usually autophosphorylated under these conditions, the result shows that the kinase activity doe ...198924212749
gas-exchange of ears of cereals in response to carbon dioxide and light : ii. occurrence of a c3-c 4 intermediate type of photosynthesis.data for the maximum carboxylation velocity of ribulose-1,5-biosphosphate carboxylase, vm, and the maximum rate of whole-chain electron transport, jm, were calculated according to a photosynthesis model from the co2 response and the light response of co2 uptake measured on ears of wheat (triticum aestivum l. cv. arkas), oat (avena sativa l. cv. lorenz), and barley (hordeum vulgare l. cv. aramir). the ratio jm/vm is lower in glumes of oat and awns of barley than it is in the bracts of wheat and i ...198924212745
phytochrome structure: peptide fragments from the amino-terminal domain involved in protein-chromophore interactions.we have undertaken a study of the structure of the amino-terminal domain of the phytochrome polypeptide purified from avena sativa l. amino-acid sequencing was used to indentify arginine 52 as the precise location of a conformation-specific cleavage of phytochrome by subtilisin. the location of the epitopes for a class of monoclonal antibodies designated type 2 has been shown to be located between approx. 10 and 20 kilodaltons (kda) from the amino terminus. these two new spatial markers, in addi ...198924212743
gas exchange of ears of cereals in response to carbon dioxide and light : i. relative contributions of parts of the ears of wheat, oat, and barley to the gas exchange of the whole organ.one cultivar each of spring wheat (triticum aestivum l. cv. arkas), oat (avena sativa l. cv. lorenz), and barley (hordeum vulgare l. cv. aramir) was chosen in order to study the relative contributions of individual bracts to the gas exchange of whole ears. the distribution and frequency of the stomata on the bracts were examined. gas exchange was measured at normal atmospheric co2 (330 μbar) and at high co2 (2000 μbar) on intact ears and on ears from which glumes or lemmas and pleae (wheat and o ...198924212553
ph-dependence of extension growth in avena coleoptiles and its implications for the mechanism of auxin action.the ph-dependence of acid-induced growth in excised segments of avena sativa coleoptiles has been reinvestigated in the ph range 3 to 7. in contrast to previous reports (e.g. dl rayle [1973] planta 114: 63-73), only acidic buffers with a ph below 5.0 induce an extension response. a ph of 3.5 to 4.0 is required to mimic auxin-mediated growth. very similar ph-response curves are obtained with both intact (abraded) and peeled coleoptiles. these results agree with the recent finding of a similarly l ...198916666736
soluble and bound apoplastic activity for peroxidase, beta-d-glucosidase, malate dehydrogenase, and nonspecific arylesterase, in barley (hordeum vulgare l.) and oat (avena sativa l.) primary leaves.an intercellular washing solution containing about 1% of the soluble protein, 0.3% or less of the glucose-6-phosphate dehydrogenase activity, but up to 20% of the peroxidase and beta-d-glucosidase activity of barley (hordeum vulgare l.) or oat (avena sativa l.) primary leaves was obtained by vacuum infiltrating peeled leaves with ph 6.9 buffered 200 millimolar nacl. after this wash, segments were homogenized in buffer, centrifuged, and the supernatant was assayed for soluble cytoplasmic enzymes. ...198916666733
phytochrome - all regions marked by a set of monoclonal antibodies reflect conformational changes.monoclonal antibodies to defined locations on six regions of the phytochrome molecule (from avena sativa l. or zea mays l.) were each found to have a different affinity toward the farred-absorbing form of phytochrome (pfr) and the red-absorbing form (pr). the differences were small, but were consistently shown by antibodies which bind to the vicinity of the aminoterminus, the carboxylterminus and to sequences in between. it seems that the conformational differences between pr and pfr extend over ...198924212493
regulation of transplasmalemma electron transport in oat mesophyll cells by sphingoid bases and blue light.long-chain sphingoid bases inhibit transplasmalemma electron transport in certain animal cells in part by inhibiting protein phosphorylation. as a first step in determining whether similar regulatory processes exist for cell surface redox activity in plants, peeled leaf segments of avena sativa l. cv garry were exposed to sphingoid bases and other long chain lipids. sphingoid bases which are the most active inhibitors of protein kinase c in animal cells inhibit transplasmalemma electron transpor ...198916666708
biosynthesis of the tonoplast h-atpase from oats.to determine whether the tonoplast-type h(+)-atpase was differentially synthesized in various parts of the oat seedling, sections of 4-day-old oat (avena sativa l. var lang) seedlings were labeled in vivo with [(35)s]methionine and atpase subunits were precipitated with polyclonal antisera. atpase subunits were detected in all portions of the seedling with the exception of the seed. lesser amounts of the 60 and 72 kilodalton polypeptides of the atpase were found in apical regions (0-5 millimeter ...198916666699
domain structure of phytochrome from avena sativa visualized by electron microscopy.highly purified phytochrome from avena sativa was visualized by electron microscopy after negative staining with uranyl acetate and after rotary shadowing with platinum. the particle shape was variable in both types of specimens, but tripartite structures resembling a 'y' were consistently observed. the tripartite substructure is composed of three globular domains each having a diameter of 7 to 8 nm and equally spaced in an equilateral triangle. the dimensions of the tripartite particle measured ...19892727087
phototropism involves a lateral gradient of growth inhibitors, not of auxin. a review.during phototropic curvature, indolyl-3-acetic acid (iaa) remains evenly distributed in the hypocotyl of sunflower (helianthus annuus l.) and in the oat (avena sativa l.) coleoptile. at the irradiated side, growth inhibiting substances accumulate. in sunflower, basipetal movement of a growth factor is not involved, since the top of the seedling can be covered or removed without affecting the photo-tropic response; this response, moreover, is independent of the rate of elongation growth. the chem ...198911541033
calcium bridges are not load-bearing cell-wall bonds in avena coleoptiles.i examined the ability of frozen-thawed avena sativa l. coleoptile sections under applied load to extend in response to the calcium chelators ethyleneglycol-bis-(beta-aminoethylether)-n,n,n',n'-tetraacetic acid (egta) and 2-[(2-bis-[carboxymethyl]amino-5-methylphenoxy)methyl]-6-methoxy-8-bis[carboxymethyl]aminoquinoline (quin ii). addition of 5 mm egta to weakly buffered (0.1 mm, ph 6.2) solutions of 2(n-morpholino) ethanesulfonic acid (mes) initiated rapid extension and wall acidification. when ...198911539809
comparison of the lipid composition of oat root and coleoptile plasma membranes: lack of short-term change in response to auxin.the total lipid composition of plasma membranes (pm), isolated by the phase partitioning method from two different oat (avena sativa l.) tissues, the root and coleoptile, was compared. in general, the pm lipid composition was not conserved between these two organs of the oat seedling. oat roots contained 50 mole percent phospholipid, 25 mole percent glycolipid, and 25 mole percent free sterol, whereas comparable amounts in the coleoptile were 42, 39, and 19 mole percent, respectively. individual ...198911537452
purification and identification of the fusicoccin binding protein from oat root plasma membrane.fusicoccin (fc), a fungal phytotoxin, stimulates the h(+) -atpase located in the plasma membrane (pm) of higher plants. the first event in the reaction chain leading to enhanced h(+) -efflux seems to be the binding of fc to a fc-binding protein (fcbp) in the pm. we solubilized 90% of the fcbp from oat (avena sativa l. cv victory) root pm in an active form with 1% octyl-glucoside. the fcbp was stabilized by the presence of protease inhibitors. the fcbp was purified by affinity chromatography usin ...198911537448
glycolytic activity in embryos of pisum sativum and of non-dormant or dormant seeds of avena sativa l. expressed through activities of pfk and ppi-pfk.a quantitative cytochemical assay for ppi-pfk activity in the presence of fru-2,6-p2 is described along with its application to determine levels of activity in embryos of pisum sativum and avena sativa. the activity of atp-pfk has also been studied in parallel as have pfk activities during the switch from dormant to non-dormant embryos in avena sativa. ppi-pfk activity has been demonstrated in all tissues of pisum sativum embryos and of avena sativa embryos including the scutellum and the aleuro ...19892541117
glutamine transport and the role of the glutamine translocator in chloroplasts.the transport of l-[(14)c]glutamine in oat (avena sativa l.) and spinach (spinacia oleracea l.) chloroplasts was studied by a conventional single-layer and a newly developed stable double-layer silicone oil filtering system. [(14)c]glutamine was actively transported into oat chloroplasts against a concentration gradient. metabolite uptake was greatly affected by the endogenous dicarboxylate pools, which could be easily changed by preloading the chloroplast with specific exogenous substrate. glut ...198816666419
mapping of antigenic domains on phytochrome from etiolated avena sativa l. by immunoblot analysis of proteolytically derived peptides.several monoclonal antibodies to phytochrome that interact with putative functionally important domains have been previously identified. the locations of some of these domains are determined here by epitope mapping experiments that utilize immunoblot analyses of proteolytically degraded phytochrome. seven independent epitopes are identified. an epitope that is recognized by monoclonal antibody oat-25 is confirmed to be wholly located near the n terminus of phytochrome. this domain undergoes a co ...19882463784
peripheral and integral subunits of the tonoplast h+-atpase from oat roots.the subunit organization of the tonoplast h+-pumping atpase from oat roots (avena sativa l. var. lang) was investigated. tonoplast vesicles were treated with low ionic strength solutions (0.1 mm 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid buffer or 0.1 mm na edta), carbonate, or a chaotropic reagent (ki), and then centrifuged to give a soluble fraction and a pellet. treatments with low ionic strength solutions or ki resulted in 70-80% reduction in the membrane-associated atpase activity, ...19882903155
phototropic fluence-response relations for avena coleoptiles on a clinostat.phototropism of avena sativa l. has been characterized using a clinostat to negate the gravitropic response. the kinetics for development of curvature was measured following induction by a single pulse of blue light (bl), five pulses of bl at 20-min intervals, and this same pulsed-light regime following a 2-h red light (rl) pre-irradiation. a final curvature of about 14° is expressed within 180 min following the single pulse; a final curvature of about 62° in about 240 min following five pulses ...198824220772
pulse-induced phototropisms in oat and maize coleoptiles.phototropisms induced by a pulse (1-30 seconds) of blue light in red-light-grown coleoptiles of oats (avena sativa l.) and maize (zea mays l.) were investigated in terms of fluence-response relationships and time courses. phototropic stimulation was made by a laser beam (457.9 nanometers), allowing application of high-fluence pulses. the phototropic fluence-response curves for oats and maize revealed two peaks in the positive range, thus indicating the occurrence of two separable pulse-induced p ...198816666391
4-amino-5-hexynoic acid-a potent inhibitor of tetrapyrrole biosynthesis in plants.4-amino-5-hexynoic acid, a suicide inactivator of the mammalian pyridoxal phosphate-dependent 4-aminobutyric acid:2-oxoglutaric acid aminotransferase, inhibits phytochrome and chlorophyll synthesis in developing oat (avena sativa l.), corn (zea mays l.), pea (pisum sativum l.), and cucumber (cucumis sativus l.) seedlings. in avena and cucumis seedlings, respectively, inhibition of phytochrome and chlorophyll accumulation by 4-amino-5-hexynoic acid can be significantly reversed by application of ...198816666377
competency for graviresponse in the leaf-sheath pulvinus of avena sativa: onset to loss.the development of the leaf-sheath pulvinus of oat (avena sativa l. cv. victory) was studied in terms of its competency to respond to gravistimulation. stages of onset of competency, maximum competency and loss of competency were identified, using the length of the supertending internode as a developmental marker. during the early phases in the onset of competency, the latency period between stimulus and graviresponse decreased and the steady state response rate increased significantly. when ful ...198811538847
rapid transcriptional regulation by phytochrome of the genes for phytochrome and chlorophyll a/b-binding protein in avena sativa.we have examined phytochrome-regulated transcription of phytochrome (phy) and chlorophyll a/b binding protein (cab) genes in dark-grown avena seedlings by using run-on transcription in isolated nuclei. kinetic analysis of phy transcription following pulse-light treatments to produce various amounts of pfr, the active form of phytochrome, leads to these conclusions. (i) transcription decreases rapidly (discernible within 5 min) after pfr formation, reaching an essentially undetectable level by 1 ...19882463467
potentials for exploiting allelopathy to enhance crop production.strategies for utilizing allelopathy as an aid in crop production include both avoidance and application protocols. there are immediate opportunities for management of weed and crop residues, tillage practices, and crop sequences to minimize crop losses from allelopathy and also to use allelopathic crops for weed control. varieties of grain and forage sorghums (sorghum spp.), sunflower (helianthus annuus l.), oats (avena sativa l.), wheat (triticum sativum l.),rye (secale cereale l.), and others ...198824277097
photoprotection of phytochrome.high-fluence-rate white light is shown to retard the degradation of phytochrome in etiolated seedlings of four different species: amaranthus caudatus, phaseolus radiatus (mung bean), pisum sativum (garden pea), and avena sativa (oat). in amaranthus, a high photon fluence rate (approx. 1000 μmol · m(-2) · s(-1)) preserved nearly 50% of the total phytochrome over a period of 5 h; at 3 μmol · m(-2) · s(-1), less than 8% remained over the same period. kinetics of the loss of total phytochrome could ...198824221928
chitinases and beta-1,3-glucanases in the apoplastic compartment of oat leaves (avena sativa l.).to isolate chitinases and beta-1,3-glucanases from the intercellular space of oats (avena sativa l.), primary leaves were infiltrated with buffer and subjected to gentle centrifugation to obtain intercellular washing fluid (iwf). approximately 5% of the chitinase and 10% of the beta-1,3-glucanase activity of the whole leaf were released. only small amounts (0.01-0.03%) of the intracellular marker malate-dehydrogenase were released into the iwf during infiltration. activities of chitinase and bet ...198816666294
molecular features affecting the biological activity of the host-selective toxins from cochliobolus victoriae.the structures of the toxins produced by cochliobolus victoriae, victorin b, c, d, e, and victoricine, have recently been established. these toxins and modified forms of victorin c were tested for their effect on dark co(2) fixation in susceptible oat (avena sativa) leaf slices. half-maximal inhibition of dark co(2) fixation occurred with the native toxins in the range of 0.004 to 0.546 micromolar. an essential component for the inhibitory activity of victorin is the glyoxylic acid residue, part ...198816666275
regulation of electrogenic proton pumping by auxin and fusicoccin as related to the growth of avena coleoptiles.the temporal relations between early responses to indoleacetic acid (iaa), proton secretion, hyperpolarization of the membrane potential, and growth change during the incubation of segments of oat (avena sativa l.) coleoptiles in a low salt medium. when iaa is added after pretreatment of several hours, proton secretion increases after a latency of 7 minutes and reaches its maximum 10 to 15 minutes later. this timing coincides with both the increase in growth of the segments and the hyperpolariza ...198816666253
subcellular compartmentation of fructose 2,6-bisphosphate in oat mesophyll cells.evacuolated mesophyll protoplasts from oat (avena sativa l.) were fractionated by a membrane-filtration technique. this method of rapid quenching of metabolic reactions permitted estimation of the in-vivo pools of fructose 2,6-bisphosphate (fru2,6bisp) in the cytosol, chloroplasts and mitochondria. vacuolar fru2,6bisp was calculated as the difference between control protoplasts and evacuolated ones. the results indicate that fru2,6bisp is exclusively cytosol-located in oat mesophyll protoplasts. ...198824221713
respiration of mitochondria isolated from leaves and protoplasts of avena sativa.mitochondria isolated from mesophyll protoplasts differed from mitochondria isolated directly from leaves of avena sativa in that protoplast mitochondria (a) had a lower overall respiratory capacity, (b) were less able to use low concentrations of exogenous nadh, (c) did not respond rapidly or strongly to added nad, (d) appeared to accumulate more oxaloacetate, and (e) oxidized both succinate and tetramethyl-p-phenylene-diamine (an electron donor for cytochrome oxidase) more slowly than did leaf ...198816666211
molecular characterization of oat seed globulins.we have isolated full-length cdna clones that encode oat (avena sativa) seed storage globulin mrnas from a cdna library in the expression vector lambda gtll. the longest of these clones, pog2, has an 1840-base pair insert that encodes a complete precursor subunit with a signal peptide of 24 amino acids followed by an acidic polypeptide of 293 amino acids and a basic polypeptide of 201 amino acids. near the c terminus of the acidic polypeptide are four repeats of a highly conserved, glutamine-ric ...198816666210
utilization of microbial siderophores in iron acquisition by oat.iron uptake by oat (avena sativa cv victory) was examined under hydroponic chemical conditions that required direct utilization of microbial siderophores for iron transport. measurements of iron uptake rates by excised roots from the hydroxamate siderophores, ferrichrome, ferrichrome a, coprogen, ferrioxamine b (fob), and rhodotorulic acid (ra) showed all five of the siderophores supplied iron, but that fob and ra were preferentially utilized. fob-mediated iron uptake increased four-fold when ro ...198816666207
elimination of the adverse effects of urea fertilizer on seed germination, seedling growth, and early plant growth in soil.the rapidly increasing importance of urea fertilizer in world agriculture has stimulated research to find methods of reducing the problems associated with the use of this fertilizer. one of these problems is that urea has adverse effects on seed germination, seedling growth, and early plant growth in soil. because there is evidence that these adverse effects are caused largely, if not entirely, by ammonia produced through hydrolysis of urea fertilizer by soil urease, we explored the possibility ...198816593951
subcellular localization of proteases in developing leaves of oats (avena sativa l.).the distribution and subcellular localization of the two major proteases present in oat (avena sativa l. cv victory) leaves was investigated. both the acidic protease, active at ph 4.5, and the neutral protease, active at ph 7.5, are soluble enzymes; a few percent of the enzyme activity was ionically bound or loosely associated with organellar structures sedimenting at 1000g. on the average, 16% of the acidic protease could be washed out of the intercellular space of the leaf. since isolated pro ...198816666179
characteristics of photosynthate partitioning during chloroplast development in avena leaves.the first leaves (40 millimeters long) of 4-day-old light-grown avena sativa l. cv victory i seedlings contained a complete age sequence of cells from the base to the tip, and within these tissues all stages of chloroplast development could be observed. although chloroplasts underwent progressive development, a marked increase in number of thylakoids per granum, in chloroplast volume, and in chlorophyll content occurred in the region between 20 and 30 millimeters from the base. photosynthetic co ...198816666164
inhibition of phytochrome synthesis by the transaminase inhibitor, 4-amino-5-fluoropentanoic acid.gardner and gorton (1985 plant physiol 77: 540-543) demonstrated that the transaminase inhibitor gabaculine (5-amino-1,3-cyclohexadienyl-carboxylic acid) inhibits the initial synthesis and resynthesis of spectrophotometrically detectable phytochrome in vivo. another mechanism-based transaminase inhibitor, 4-amino-5-fluoropentanoic acid (afpa), is examined in this report for its effects on phytochrome synthesis in developing etiolated seedlings. preemergence treatment with afpa was found to inhib ...198816666131
modifications of sulfhydryl groups on phytochrome and their influence on physicochemical differences between the red- and far-red-absorbing forms.phytochrome extracted from shoots of dark-grown rye (secale cereale cv rymin) and oat (avena sativa cv garry) as the far-red-form (pfr) and/or under conditions conducive to oxidation exhibited a blue shift in the visible absorption maximum of its red-light-absorbing form (pr) relative to that measured in vivo. this spectral alteration could not be reversed but could be prevented by inclusion of 10 millimolar diethyldithiocarbamate and 140 millimolar 2-mercaptoethanol in homogenization buffers. s ...198816666102
dissipation of ph gradients in tonoplast vesicles and liposomes by mixtures of acridine orange and anions: implications for the use of acridine orange as a ph probe.acridine orange altered the response to anions of both atp and in-organic pyrophosphate-dependent ph gradient formation in tonoplast vesicles isolated from oat (avena sativa l.) roots and red beet (beta vulgaris l.) storage tissue. when used as a fluorescent ph probe in the presence of i(-), clo(3) (-), no(3) (-), br(-), or scn(-), acridine orange reported lower ph gradients than either quinacrine or [(14)c]methylamine. acridine orange, but not quinacrine, reduced [(14)c]methylamine accumulation ...198816666073
cytochemical localization of atpase activity in oat roots localizes a plasma membrane-associated soluble phosphatase, not the proton pump.cytochemical techniques employing lead-precipitation of enzymically released inorganic phosphate have been widely used in attempts to localize the plasma membrane proton pump (h(+)-atpase) in electron micrographs. using avena sativa root tissue we have performed a side-by-side comparison of atpase activity observed in electron micrographs with that observed in in vitro assays using atpases found in the soluble and plasma membrane fractions of homogenates. cytochemical analysis of oat roots, whic ...198816665998
n,n'-dicyclohexylcarbodiimide-binding proteolipid of the vacuolar h+-atpase from oat roots.the inhibitor n,n'-dicyclohexylcarbodiimide (dccd) was used to probe the structure and function of the vacuolar h+-translocating atpase from oat roots (avena sativa var. lang). the second-order rate constant for dccd inhibition was inversely related to the concentration of membrane, indicating that dccd reached the inhibitory site by concentrating in the hydrophobic environment. [14c]dccd preferentially labeled a 16-kda polypeptide of tonoplast vesicles, and the amount of [14c]dccd bound to the ...19882891708
rapid elicitation of second messengers by nanomolar doses of triacontanol and octacosanol.triacontanol (tria) increases the dry weight and alters the metabolism of rice (oryza sativa l.) seedlings within 10 min of application to either the shoots or roots. this activity is prevented if octacosanol (octa, c28 primary alcohol) is applied with the tria on the roots or shoots. triacontanol activity is also stopped if the octa is applied at least 1 min before the tria on the opposite part of the seedling.triacontanol rapidly elicits a second messenger that moves rapidly throughout the pla ...198824226183
reduction of net photosynthesis in oats after treatment with low concentrations of ozone.oats (avena sativa l. cv titus) were exposed to low concentrations of o3 in an assimilation chamber system. net photosynthesis (net co2 uptake), measured before and after o3 fumigation, showed significantly different responses for leaves of different age. the oldest active leaf was the most sensitive to o3. net photosynthesis was depressed after 2 h with 0.075 ppm (150 microg m(-3)) o3. for leaves exposed to 0.150 ppm (300 microg m(-3)) o3 for 2 h, net photosynthesis was reduced significantly fo ...198815092555
altered growth response to exogenous auxin and gibberellic acid by gravistimulation in pulvini of avena sativa.pulvini of excised segments from oats (avena sativa l. cv victory) were treated unilaterally with indoleacetic acid (iaa) or gibberellic acid (ga3) with or without gravistimulation to assess the effect of gravistimulation on hormone action. optimum pulvinus elongation growth (millimeters) and segment curvature (degrees) over 24 hours were produced by 100 micromolar iaa in vertical segments. the curvature response to iaa at levels greater than 100 micromolar, applied to the lower sides of gravist ...198811537872
uptake of 226ra by established vegetation and black cutworm larvae, agrotis ipsilon (class insecta: order lepidoptera), on u mill tailings at elliot lake, canada.radium-226 levels in samples from an inactive u tailings site at elliot lake, ontario, canada, were: 9,140 +/- 500 mbq g-1 dry weight in the substrate; 62 +/- 1 mbq g-1 dry weight in rye, secale cereale, and less than 3.7 mbq g-1 dry weight in oats, avena sativa, the dominant species established by revegetation of the tailings; and 117 +/- 7 mbq g-1 dry weight in washed and unwashed black cutworm larvae. concentration ratios were: vegetation to tailings 0.001-0.007; black cutworms to vegetation ...19883391775
phosphorylation of the plasma-membrane h(+)-atpase of oat roots by a calcium-stimulated protein kinase.when plasma-membrane vesicles isolated from oat (avena sativa l.) root cells were incubated with [γ-(32)p]atp, the h(+)-atpase was found to be phosphorylated at serine and threonine residues. phosphotyrosine was not detected. endogenous atpase kinase activity was also observed in plasma-membrane vesicles isolated from potato (solanum tuberosum l.) root cells as well as from yeast (saccharomyces cerevisiae). identity of the phosphorylated oat root mr=100 000 polypeptide as the atpase was confirme ...198824226688
role of mycorrhizal infection in the growth and reproduction of wild vs. cultivated plants : i. wild vs. cultivated oats.we tested the hypothesis that mycorrhizal infection benefits wild plants to a lesser extent than cultivated plants. this hypothesis stems from two observations: (1) mycorrhizal infection improves plant growth primarily by increasing nutrient uptake, and (2) wild plants often possess special adaptations to soil infertility which are less pronounced in modern cultivated plants. in the first experiment, wild (avena fatua l.) and cultivated (a. sativa l.) oats were grown hydroponically at four diffe ...198828311275
hemin inhibits ubiquitin-dependent proteolysis in both a higher plant and yeast.in eukaryotes, a major route for atp-dependent protein breakdown proceeds through covalent intermediates of target proteins destined for degradation and the highly conserved, 76 amino acid protein ubiquitin. in rabbit reticulocytes, it has been shown that hemin effectively inhibits this pathway by blocking the catabolism of ubiquitin-protein conjugates [ki = 25 microm (haas, a. l., & rose, i. a. (1981) proc. natl. acad. sci. u.s.a. 78, 6845-6848)]. here, we demonstrate that hemin is also an effe ...19882839230
agrobacterium-mediated infectivity of cloned digitaria streak virus dna.a monomeric clone of double-stranded dna synthesized in vitro dna of the geminivirus digitaria streak (dsv) was subcloned as a tandem dimeric unit into a binary vector of agrobacterium tumefaciens, creating a plasmid pds2. inoculation of digitaria sanguinalis with a. tumefaciens carrying pds2 resulted in viral infection. the symptoms, virus particles, and dna forms obtained were indistinguishable from those of a natural dsv infection of d. sanguinalis. inoculations have also induced infections i ...19883341112
h+-atpase from plasma membranes of saccharomyces cerevisiae and avena sativa roots: purification and reconstitution. 19882906717
oats tolerant of pseudomonas syringae pv. tabaci contain tabtoxinine-beta-lactam-insensitive leaf glutamine synthetases.pseudomonas syringae pv. tabaci, a commonly recognized leaf pathogen of tobacco, can infest the rhizosphere of many plants, including oats. normal oat plants do not survive this infestation as a consequence of the complete and irreversible inactivation of all of their glutamine synthetases by tabtoxinine-beta-lactam (tbetal), a toxin released by pv. tabaci. we have identified a population of oat (avena sativa l. var lodi) plants that are tolerant of pv. tabaci. the tolerant plants had no detecta ...198816666304
development of oat prothylakoids into thylakoids during greening does not change transmembrane galactolipid asymmetry but preserves the thylakoid bilayer.the lipase from rhizopus arrhizus and the lipolytic acyl hydrolase from potato tubers have been used to determine the transmembrane distribution of monogalactosyldiacylglycerol (mgdg) and digalactosyldiacylglycerol (dgdg) in prothylakoids and thylakoids from oat (avena sativa). both galactolipids were found to be asymmetrically distributed. the molar outside/inside distribution was 70 +/- 8/30 +/- 8 for mgdg and 10 +/- 4/90 +/- 4 for dgdg in the prothylakoid membrane. mature thylakoids presented ...198816666318
red light-induced formation of ubiquitin-phytochrome conjugates: identification of possible intermediates of phytochrome degradation.phytochrome is the photoreceptor that controls red light-mediated morphogenesis in higher plants. it exists in two photointerconvertible forms, a red light-absorbing form, pr, and a far-red light-absorbing form, pfr. because photoconversion of pr to pfr by a brief light pulse decreases the in vivo half-life of this chromoprotein by a factor of approximately 100, this system offers a unique way to modulate the turnover rate of a specific protein and hence study the mechanisms responsible for sele ...198716593800
nematode response to cool season annual graminaceous species and cultivars.the response of 29 rye, oat, triticale, and wheat cultivars to selected nematode species was determined in the greenhouse. variability in nematode root galling and final nematode population densities in root and soil in response to cool season annual graminaceous crops occurred for spiral (helicotylenchus dihystera), stubby root (paratrichodorus minor), and root-knot (meloidogyne incognita) nematodes. although none of the graminaceous crops supported m. incognita at levels as high as the suscept ...198719290289
probing the catalytic subunit of the tonoplast h+-atpase from oat roots. binding of 7-chloro-4-nitrobenzo-2-oxa-1,3,-diazole to the 72-kilodalton polypeptide.the purified tonoplast h+-atpase from oat roots (avena sativa l. var. lang) consists of at least three different polypeptides with masses 72, 60, and 16 kda. we have used covalent modifiers (inhibitors) and polyclonal antibodies to identify the catalytic subunit of the h+-pumping atpase. the inactivation of atpase activity by 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (nbd-cl, an adenine analog) was protected by mgatp or mgadp, and showed kinetic properties consistent with active site-directed inhi ...19872884218
a monoclonal antibody specific for the red-absorbing form of phytochrome.characterisation of a new monoclonal antibody (mab), designated las 41, directed against 124-kilodalton (kda) etiolated-oat (avena sativa l.) phytochrome, indicates that it recognises an epitope unique to the red-light-absorbing form, pr. in a solid-phase enzyme-linked immunosorbent assay (elisa), las 41 exhibits a seven- to eight-fold higher affinity for pr than for the far-red-light-absorbing form of phytochrome, pfr. in addition, in immunoprecipitation assays las 41 effectively precipitates 1 ...198724226075
the levels of two distinct species of phytochrome are regulated differently during germination in avena sativa l.the abundance and molecular mass of phytochrome in germinating embryos of a. sativa (oat) grown in light or darkness have been monitored using immunoblot and spectrophotometric assays. immunoblot analysis shows that imbibed but quiescent embryos have two immunochemically distinct species of phytochrome with monomeric molecular masses of 124 and 118 kda (kdalton). the 118-kda species has the properties of the 118-kda phytochrome extracted from fully green oat tissue (j.g. tokuhisa, s.m. daniels, ...198724225921
do some plant responses to cytokinins involve the cyanide-resistant respiratory pathway?a disengagement of the cyanide-resistant, alternative respiratory pathway in soybean (glycine max (l.) merr.) callus tissue was observed prior to the start of deoxyisoflavone production stimulated by addition of the cytokinin benzyladenine. to test whether this loss of alternativepathway activity was part of the response to cytokinin, inhibitors of the alternative pathway were assayed for their ability to elicit cytokinin-like responses. salicylhydroxamic acid (sham) was found to produce a deoxy ...198724225916
latency of plasma membrane h-atpase in vesicles isolated by aqueous phase partitioning : increased substrate accessibility or enzyme activation.the properties of the plasma membrane h(+)-atpase and the cause of its latency have been studied using a highly purified plasma membrane fraction from oat (avena sativa l., cv victory) roots, prepared by aqueous two-phase partitioning. the atpase has a maximum specific activity (at 37 degrees c) in excess of 4 micromoles inorganic phosphate per milligram protein per minute in the presence of nondenaturing surfactants. it is inhibited by more than 90% by vanadate, is specific for atp, has a ph op ...198716665762
improving grain yield in backcross populations from avena sativa × a. sterilis matings by using independent culling for harvest index and vegetative growth index or unit straw weight.grain yield was selected in avena sativa x a. sterilis populations of segregates by applying independent culling for harvest index and either vegetative growth index or unit straw weight. samples of lines intensively selected for harvest index had high harvest index but low grain yield because they had low vigor. populations intensively selected for growth rate index or unit straw weight had high biological yield but low harvest index. intensive selection for grain yield per se resulted in sampl ...198724240224
some characteristics of anion transport at the tonoplast of oat roots, determined from the effects of anions on pyrophosphatedependent proton transport.the effects of anions on inorganicpyrophosphate-dependent h(+)-transport in isolated tonoplast vesicles from oat (avena sativa l.) roots were determined. both fluorescent and radioactive probes were used to measure formation of ph gradients and membrane potential in the vesicles. pyrophosphate hydrolysis by the h(+)-translocating pyrophosphatase was unaffected by anions. nonetheless, some anions (cl(-), br(-) and no3-) stimulated h(+)-transport while others (malate, [formula: see text] and imino ...198724225792
effects of diclofop and diclofop-methyl on the membrane potentials of wheat and oat coleoptiles.electrophysiological measurements were made on the mesophyll cells of wheat (triticum aestivum l. cv waldron) and oat (avena sativa l. cv garry) coleoptiles treated either with the herbicide diclofop-methyl (methyl 2-(4-(2',4'-dichlorophenoxy)phenoxy)propanoate), or it's primary metabolite diclofop, (2-(4-(2',4'-dichlorophenoxy)phenoxy)-propanoic acid). application of a 100 micromolar solution of diclofop-methyl to wheat coleoptiles had little or no effect on the membrane potential (e(m)), howev ...198716665655
immunocytological and chemical studies on the stromacentre-forming protein from avena plastids.the stromacentre (sc), a particular structure in the plastids of avena, was isolated from etioplasts of avena sativa by density gradient centrifugation and then analyzed and compared with ribulose-1,5-bisphosphate carboxylase-oxygenase (rubpcase) from a. sativa, with pyrenoids of chlorella vulgaris and with the "stromacentre" of opuntia. purified sc-elements consisted of protein subunits with a relative molecular weight of 63 kda, different from the isolated rubpcase of a. sativa as shown by sod ...198724225705
chloroplast genome evolution in the genus avena.the genus avena contains five different chloroplast genomes, i-v. a physical map of chloroplast (ct) dna of avena sativa (type i chloroplast genome) was constructed using three restriction endonucleases, psti, sali and smai. this genome is ca. 135.5 kbp in size, and contains two inverted repeats of ca. 22.5 kbp each, separated by a large (ca. 79.0 kbp) and small (ca. 12.5 kbp) single copy region. the rbcl gene which codes for the large subunit of ribulose 1,5-bisphosphate carboxylase, was locate ...198717246394
storage protein synthesis during oat (avena sativa l.) seed development.oat (avena sativa l.) seeds harvested at 2-day intervals from anthesis to maturity were tested for their ability to incorporate [(35)s]sulfate into protein. incorporation of [(35)s]sulfate into tca-insoluble material began 2 to 4 days postanthesis (dpa), reached a peak 14 to 16 dpa, and was barely detectable by 24 dpa. incorporation of label into globulin was parallel to total protein accumulation, and averaged about 85% of the total protein synthesis. sodium dodecyl sulfate-polyacrylamide gel e ...198716665440
phytochrome chromophore biosynthesis : both 5-aminolevulinic acid and biliverdin overcome inhibition by gabaculine in etiolated avena sativa l. seedlings.etiolated avena sativa l. seedlings grown in the presence of gabaculine (5-amino-1,3-cyclohexadienylcarboxylic acid) contained reduced levels of phytochrome as shown by spectrophotometric and immunochemical assays. photochromic phytochrome levels in gabaculine-grown plants were estimated to be 20% of control plants, while immunoblot analysis showed that the phytochrome protein moiety was present at approximately 50% of control levels. gabaculine-grown seedlings administered either 5-aminolevulin ...198716665435
inhibition and labeling of the plant plasma membrane h-atpase with n-ethylmaleimide.h(+)-atpase activity in plasma membranes isolated from avena sativa root cells is inhibited by n-ethylmaleimide, a covalent modifier of protein sulfhydryl groups. the rate of inhibition is reduced by adp, mgadp, and mgatp, but even at 40 millimolar adp the enzyme is only partially protected against inactivation. when plasma membranes are treated wth n-[2-(3)h]ethylmaleimide and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis, prominent radioactive bands appear at m(r)=100,0 ...198716665375
biomass production and nitrogen content of c3- and c4- grasses in pure and mixed culture with different nitrogen supply.two c3 grasses (hordeum vulgare l., avena sativa l.) and two c4 grasses (panicum miliaceum l., panicum crus-galli l.) were cultivated in standard soil in the open air in pure cultures and in various mixed cultures at low and high nitrogen fertilization levels. after three months the dry weight, length and nitrogen content of the aboveground and below-ground parts of the plants and the shoot/root ratios were determined. hordeum vulgare was the most successful species irrespective of the nitrogen ...198728312237
long-term acid-induced wall extension in an in-vitro system.when frozen-thawed avena sativa l. coleoptile and cucumis sativa l. hypocotyl sections, under tension, are acid-treated, they undergo rapid elongation (acid-extension). the acid-extension response consists of two concurrent phases: a burst of extension which decays exponentially over 1-2 h (exe), and a constant rate of extension (ce) which can persist for at least 6 h. the extension (al) is closely represented by the equation: δl = a - a · e (kt) + c · t where a is the total extension of the exp ...198724232968
site of synthesis of the enzymes of the pyrimidine biosynthetic pathway in oat (avena sativa l.) leaves.heat-bleached oat (avena sativa l. cv porter) leaves lacking 70s chloroplast ribosomes have been used to demonstrate that four chloroplast-localized enzymes of pyrimidine nucleotide biosynthesis: aspartate carbamoyl-transferase, dihydroorotase, orotidine phosphoribosyl-transferase, and orotidine-5'-phosphate decarboxylase, are synthesized on cytoplasmic ribosomes. two other chloroplast enzymes, carbamoyl phosphate synthetase, involved in both pyrimidine and arginine biosynthesis, and ornithine c ...198716665303
potential-dependent anion transport in tonoplast vesicles from oat roots.potential-dependent anion movement into tonoplast vesicles from oat roots (avena sativa l. var lang) was monitored as dissipation of membrane potentials (deltapsi) using the fluorescence probe oxonol v. the potentials (positive inside) were generated with the h(+)-pumping pyrophosphatase, which is k(+) stimulated and anion insensitive. the relative rate of deltapsi dissipation by anions was used to estimate the relative permeabilities of the anions. in decreasing order they were: scn(-) (100) > ...198716665276
comparison of the protein conformations between different forms (pr and pfr) of native (124 kda) and degraded (118/114 kda) phytochromes from avena sativa. 19873562595
the physiological role of lipoxygenase in ethylene formation from 1-aminocyclopropane-1-carboxylic acid in oat leaves.in order to understand the physiological significance of the in-vitro lipoxygenase (ec 1.13.11.12)-mediated ethylene-forming system (j.f. bousquet and k.v. thimann 1984, proc. natl. acad. sci. usa 81, 1724-1727), its characteristics were compared to those of an in-vivo ethylene-forming system. while oat (avena sativa l.) leaves, as other plant tissues, preferentially converted only one of the 1-amino-2-ethylcyclopropane-1-carboxylic acid (aec) isomers to 1-butene, the lipoxygenase system convert ...198724232877
effect of ozone on net photosynthesis in oat (avena sativa) and duckweed (lemna gibba).short exposure to ozone depressed photosynthesis in both oat and duckweed at concentrations above 140 microg m(-3) and 300 microg m(-3), respectively. the effect on exposed oat flag leaves was age-dependent, with maximum susceptibility to ozone 10-20 days after emergence of the panicle. in duckweed, photosynthesis was more sensitive to differences in ozone concentration than to differences in duration of exposure.198715092702
long-term acid-induced wall extension in an in-vitro system.when frozen-thawed avena sativa l. coleoptile and cucumis sativa l. hypocotyl sections, under tension, are acid-treated, they undergo rapid elongation (acid-extension). the acid-extension response consists of two concurrent phases: a burst of extension which decays exponentially over 1-2 h (exe), and a constant rate of extension (ce) which can persist for at least 6h. the extension (delta l) is closely represented by the equation: delta l = a-a e(-kt) + c t where a is the total extension of the ...198711539098
association of two measures of vegetative growth rate with other traits in inter and intraspecific matings of oats.f2-derived oat lines from inter (avena sativa l. x a. sterilis l.) and intraspecific (among a. sativa cultivars) matings were evaluated in the f3, f4, and f5 generations for heading date, grain and straw yields, biomass, vegetative dry weight at anthesis, vegetative growth rates until anthesis (gra) and until maturity (grm), and harvest index. the associations of gra and grm with harvest index ranged from zero to slightly negative. the positive correlations of gra and grm with grain yield were s ...198624248196
immunoprecipitation of phytochrome from green avena by rabbit antisera to phytochrome from etiolated avena.thirty-nine antiserum preparations from eight rabbits were screened for their ability to precipitate the immunochemically distinct phytochrome that is obtained from green oat (avena sativa l.) shoots. the antisera were obtained from rabbits immunized with either proteolytically degraded, but still photoreversible, 60-kda (kilodalton) phytochrome, or approx. 120-kda phytochrome, both of which were purified from etiolated oat shoots. the ability of these antisera to precipitate phytochrome from gr ...198624232327
isoelectric focusing of oat root membranes.the feasibility of purifying subcellular membranes, especially plasma membranes, from oat roots using isoelectric focusing has been examined. membranes from oat (avena sativa l. cv garry) root homogenates were fractionated using discontinuous sucrose density gradient centrifugation and then electrofocused using a microanalytical isoelectric focusing column. the column contained either a broad-range (ph 3-10) or narrow-range (ph 3-6) ph gradient stabilized by a 5 to 15% ficoll gradient. results f ...198616665016
in vitro and in vivo protein phosphorylation in avena sativa l. coleoptiles: effects of ca2+, calmodulin antagonists, and auxin.in vitro and in vivo protein phosphorylations in oat (avena sativa l.) coleoptile segments were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and by two-dimensional gel electrophoresis. in vitro phosphorylation of several polypeptides was distinctly promoted at 1 to 15 micromolar free ca2+ concentrations. ca2(+)-stimulated phosphorylation was markedly reduced by trifluoperazine, chlorpromazine, and naphthalene sulfonamide (w7). two polypeptides were phosphorylated both un ...198611539102
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