| phytochrome levels in light-grown avena change in response to end-of-day irradiations. | the effect of 15-minute end-of-day irradiations on photoreversible phytochrome levels in light-grown oat (avena sativa l., cv garry) seedlings was investigated. oat seedlings were grown in a cycle of 8 hours of natural daylight and 16 hours of complete darkness, from sowing until harvest at day 10. the level of extractable, photoreversible phytochrome per unit fresh weight was 60% higher after end-of-day far-red irradiation than after either end-of-day red irradiation or end-of-day far-red follo ... | 1992 | 16669098 |
| auxin-induced growth of avena coleoptiles involves two mechanisms with different ph optima. | although rapid auxin-induced growth of coleoptile sections can persist for at least 18 hours, acid-induced growth lasts for a much shorter period of time. three theories have been proposed to explain this difference in persistence. to distinguish between these theories, the ph dependence for auxin-induced growth of oat (avena sativa l.) coleoptiles has been determined early and late in the elongation process. coleoptile sections from which the outer epidermis was removed to facilitate buffer ent ... | 1992 | 11537888 |
| distribution of phytochrome and chlorophyll-a/b-binding-protein mrnas in etiolated avena seedlings. | in 4-d-old dark-grown oat (avena sativa l.) seedlings, the majority of the type-i-phytochrome (phya) mrna was found within 10 mm of the tip of the coleoptile sheath and in the mesocotyl node; almost none was detected in the enclosed primary leaf. in contrast, chlorophyll-a/b-binding-protein (cab) mrnas were found almost exclusively in the enclosed primary leaf and were barely detectable in total-rna samples from the coleoptile sheath or mesocotyl node of red-light-treated etiolated seedlings. se ... | 1992 | 24178148 |
| subunit composition and organization of the vacuolar h-atpase from oat roots. | the vacuolar h(+)-translocating atpase (h(+)-atpase), originally reported to consist of three major subunits, has been further purified from oat roots (avena sativa var lang) to determine the complete subunit composition. triton-solubilized atpase activity was purified by gel filtration on sephacryl s400 and ion-exchange chromatography (q-sepharose). atp hydrolysis activity of purified preparations was inhibited by 100 nanomolar bafilomycin a(1), a specific vacuolar-type atpase inhibitor. the pu ... | 1992 | 16668846 |
| dissociation and reassembly of the vacuolar h-atpase complex from oat roots. | conditions for the dissociation and reassembly of the multi-subunit vacuolar proton-translocating atpase (h(+)-atpase) from oat roots (avena sativa var lang) were investigated. the peripheral sector of the vacuolar h(+)-atpase is dissociated from the membrane integral sector by chaotropic anions. membranes treated with 0.5 molar ki lost 90% of membrane-bound atp hydrolytic activity; however, in the presence of mg(2+) and atp, only 0.1 molar ki was required for complete inactivation of atpase and ... | 1992 | 16668845 |
| comparison of the outer and inner epidermis : inhibition of auxin-induced elongation of maize coleoptiles by glucan antibodies. | polyclonal antibodies, raised against beta-d-glucans prepared from oat (avena sativa l.) caryopses, cross-reacted specifically with (1-->3),(1-->4)-beta-d-glucans when challenged in a dot blot analysis of related polymers bound to a cellulose thin layer chromatography plate. the antibodies suppressed indoleacetic acid (iaa)-induced elongation of segments from maize (zea mays l.) coleoptiles when the outer surface was abraded. however, iaa-induced elongation of nonabraded segments or segments wit ... | 1992 | 16668791 |
| relationship between electron transport across the plasmalemma and a ph decrease in the bulk medium. | the hypothesis is tested that acidification of the bulk medium during transplasmalemma electron transport to ferricyanide is due solely to a requirement for charge balance. according to this hypothesis, reduction of the trivalent anion, ferricyanide, to the tetravalent anion, ferrocyanide, results in a charge difference that is balanced by protons. a coulometric device is used that rapidly and efficiently reoxidizes ferrocyanide to ferricyanide, thus maintaining a constant charge in the bulk med ... | 1992 | 16668776 |
| novel light-regulated chloroplast thylakoid membrane protein. | a 64 kilodalton chloroplast membrane polypeptide was dependent on growth irradiance with 10-fold greater quantities of the protein present in barley (hordeum vulgare) grown under 500 micromoles of photons per square meter per second compared with growth at 50 micromoles per square meter per second. the concentration of the protein was sensitive to changes in irradiance, with a slow time course for the response (days) similar to other reported light acclimation processes. the polypeptide also was ... | 1992 | 16668749 |
| k channels are responsible for an inwardly rectifying current in the plasma membrane of mesophyll protoplasts of avena sativa. | in whole-cell recording, the conductance of the plasma membrane of protoplasts isolated from mesophyll cells of leaves of oat (avena sativa) was greater for inward than outward current. the inward current in both the whole-cell mode and with isolated patches was dependent on [k(+)](o). when the membrane voltage was more positive than -50 millivolts, the membrane conductance in the whole-cell mode was low, and k(+) channels in cell-attached or outside-out patches had a low probability of being op ... | 1992 | 16668731 |
| immunochemical analysis of the temporal and tissue-specific expression of an avena sativa plasma membrane determinant. | an immunoglobulin mk monoclonal (f8ive9) antibody raised against oat (avena sativa cv garry) root homogenate has been produced and characterized. the predominant target bound by this antibody is a 62-kilodalton protein (p62) that is expressed in both oat root and oat shoot cells. treatment of the oat antigen with periodate, or with recombinant n-glycanase, affects the f8ive9 binding to the antigen, suggesting that the specific epitope for this monoclonal antibody involves a carbohydrate determin ... | 1992 | 16668621 |
| changes in the ultrastructure of cell walls, cellulose synthesis, and glucan synthase activity from gravistimulated pulvini of oat (avena sativa). | ultrastructural analyses of the cell walls from top and bottom halves of gravistimulated pulvini from oat leaves show a decrease in the density of material within the cell walls from the lower halves of pulvini after 24 h of gravistimulation. assays of cellulose synthesis with a 14c-sucrose pulse-chase experiment indicate no difference in the amount of new cellulose synthesized in top compared with bottom halves of gravistimulated pulvini. the highest rate of cellulose synthesis occurs with 12-2 ... | 1992 | 11537505 |
| the role of calcium in growth induced by indole-3-acetic acid and gravity in the leaf-sheath pulvinus of oat (avena sativa). | leaf-sheath pulvini of excised segments from oat (avena sativa l.) were induced to grow by treatment with 10 micromoles indole-3-acetic acid (iaa), gravistimulation, or both, and the effects of calcium, egta, and calcium channel blockers on growth were evaluated. unilaterally applied calcium (10 mm cacl2) significantly inhibited iaa-induced growth in upright pulvini but had no effect on growth induced by either gravity or gravity plus iaa. calcium alone had no effect on upright pulvini. the calc ... | 1992 | 11536939 |
| the outer epidermis of avena and maize coleoptiles is not a unique target for auxin in elongation growth. | a controversy exists as to whether or not the outer epidermis in coleoptiles is a unique target for auxin in elongation growth. the following evidence indicates that the outer epidermis is not the only auxin-responsive cell layer in either avena sativa l. or zea mays l. coleoptiles. coleoptile sections from which the epidermis has been removed by peeling elongate in response to auxin. the magnitude of the response is similar to that of intact sections provided the incubation solution contains bo ... | 1991 | 24186577 |
| the ph profile for acid-induced elongation of coleoptile and epicotyl sections is consistent with the acid-growth theory. | the acid-growth theory predicts that a solution with a ph identical to that of the apoplast of auxintreated tissues (4.5-5.0) should induce elongation at a rate comparable to that of auxin. different ph profiles for elongation have been obtained, however, depending on the type of pretreatment between harvest of the sections and the start of the ph-incubations. to determine the acid sensitivity under in vivo conditions, oat (avena sativa l.) coleoptile, maize (zea mays l.) coleoptile and pea (pis ... | 1991 | 24186576 |
| photoresponses of transgenic tobacco plants expressing an oat phytochrome gene. | the physiological responses of transgenic tobacco (nicotiana tabacum l.) plants that express high levels of an introduced oat (avena sativa l.) phytochrome (phya) gene to various light treatments are compared with those of wild-type (wt) plants. seeds, etiolated seedlings, and light-grown plants from a homozygous transgenic tobacco line (9a4) constructed by keller et al. (embo j, 8, 1005-1012, 1989) were treated with red (r), far-red (fr), or white light (wl) with or without supplemental fr ligh ... | 1991 | 24186338 |
| callus formation and plant regeneration from somatic embryos of oat (avena sativa l.). | globular-stage somatic embryos were isolated by vortexing friable, embryogenic callus of oat (avena sativa l.) followed by fractionation based on size. somatic embryos were most frequently found in the 300-380 μm size fraction. friable, embryogenic callus was reinitiated from 55% of isolated somatic embryos. fertile plants were regenerated from 22% of isolated somatic embryos. reinitiation of callus from somatic embryos and growth of friable, embryogenic callus was inhibited by the selective age ... | 1991 | 24221588 |
| lipids of plasma membranes prepared from oat root cells : effects of induced water-deficit tolerance. | plasma membranes were isolated from oat (avena sativa) roots by the phase-partitioning method. the membranes were exposed to repeated periods of moderate water-deficit stress, and a water-deficit tolerance was induced (acclimated plants). the plasma membranes of the controls (nonacclimated plants) were characterized by a high phospholipid content, 79% of total lipids, cerebrosides (9%) containing hydroxy fatty acids (>90% 24:1-oh) and free sterols, acylated sterylglucosides, sterylglucosides, an ... | 1991 | 16668310 |
| western blot analysis of cereal grain prolamins using an antibody to carboxyl-linked indoleacetic acid. | a monoclonal antibody raised against carboxyl-linked iaa was used in western blot analysis of storage proteins from kernels of avena sativa, pennisetum americanum, sorghum bicolor, and zea mays. iaa or an iaa-like molecule is associated with the ethanolsoluble protein fraction of the seed. western blotting of commercial zein, the major storage protein of maize, along with physicochemical evidence reported by leverone et al. ([1991] plant physiol, 96: 1070-1075) indicated that iaa is linked with ... | 1991 | 16668300 |
| conjugation of ubiquitin to proteins from green plant tissues. | conjugation of the polypeptide ubiquitin to endogenous proteins was studied in oat (avena sativa l.) plants, and particularly in green tissues. conjugating activity in leaf extracts was different from that in root extracts, and in both was less than in etiolated tissue. the conjugates were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page), and their formation was both time- and atp-dependent and had a ph optimum of about 8.2. the assay had a high affinity for atp ... | 1991 | 16668183 |
| expression of ap 3, 4 and 5 isophytochromes in etiolated oat seedlings (avena sativa l.). | type 1 phytochrome from etiolated oat seedlings was digested with v-8 protease. microsequencing of a 13 kda fragment yielded a sequence of 31 amino acids. the fragment starting with the alanine residue at position 427 of the entire phytochrome amino acid sequence revealed a heterogeneity (threonine, alanine and asparagine) at position 10. this demonstrates that the phytochrome type a genes ap3, 4 and 5 are expressed as proteins. | 1991 | 1881964 |
| some properties of the h-atpase activity present in root plasmalemma of avena sativa l. two different enzymes or one enzyme with two atp sites? | the effects of mg2+, k+ and atp on a h-atpase activity from a native plasmalemma fraction of oat roots were explored at 20 degrees c and ph 6.5. in the presence of 3 mm atp and no k+, h-atpase activity vs. [mg2+] approached a monotonic activation but it became biphasic, with a decline above 3 mm mg2+, in the presence of 20 mm k+. mg2+ inhibition occurred also in k-free solutions when [atp] was lowered to 0.05 mm. also, an apparent monotonic h-atpase activation by [k+] at 3.0 mm atp was transform ... | 1991 | 1827349 |
| functional xylem anatomy in root-shoot junctions of six cereal species. | in cereals, the formation of safety zones in the root-shoot junction could protect the vessels of roots from embolism originating in the shoot. the root-shoot junction was examined both anatomically, with a light microscope, and experimentally, using a pressurized-air method, in the base of seminal and adventitious roots of maize (zea mays l. cv. seneca 60-ii), a corngrass mutation of maize (cg mutant), sorghum (sorghum bicolor l. cv. ho-pak), winter oats (avena sativa l. cv. ogle), spring wheat ... | 1991 | 24193938 |
| avena sativa l. contains three phytochromes, only one of which is abundant in etiolated tissue. | phytochrome from leaves of light-grown oat (avena sativa l. cv. garry) plants is characterized with newly generated monoclonal antibodies (mabs) directed to it. the results indicate that there are at least two phytochromes in green oat leaves, each of which differs from the phytochrome that is most abundant in etiolated oat tissue. when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) with reference to 124-kilodalton (kda) phytochrome from etiolated oats, the two ... | 1991 | 24193935 |
| large-scale partial purification of phytochrome from green leaves of avena sativa l. | phytochrome from 10 or 11-d-old oat (avena sativa l. cv. garry) leaves, which were harvested just prior to sunset from plants grown in a greenhouse in the absence of supplemental illumination, was purified an estimated 250-fold by sequential poly(ethylenimine) and ammonium-sulfate fractionations, followed by linear-gradient hydroxyapatite chromatography. compared to earlier protocols, the one presented here is substantially more rapid, provides improved yield and purity, can be used with larger ... | 1991 | 24193933 |
| effects of diclofop and diclofop-methyl on membrane potentials in roots of intact oat, maize, and pea seedlings. | growth and electrophysiological studies in roots of intact diclofop-methyl susceptible and resistant seedlings were conducted to test the hypothesis that the herbicide acts primarily as a proton ionophore. the ester formulation of diclofop, at 0.2 micromolar, completely inhibited root growth in herbicide-susceptible oat (avena sativa l.) after a 96 hour treatment, but induced only a delayed transient depolarization of the membrane potential in oat root cortical cells. root growth in susceptible ... | 1991 | 16668091 |
| electrical membrane properties of leaves, roots, and single root cap cells of susceptible avena sativa: effect of victorin c. | the effect of the purified host-selective toxin victorin c, a cyclized penta peptide, was compared to that of cccp and vanadate on membrane functions of susceptible leaves, roots, and single root cap cells of avena sativa with conventional electrophysiology. the plasmalemma depolarized irreversibly by about 80 millivolts and to below the diffusion potential within 1 hour. concentrations as low as 12.5 picomolar were effective in the susceptible but not the resistant cultivar. electrical membrane ... | 1991 | 16668038 |
| diurnal periodicity of chalcone-synthase activity during the development of oat primary leaves. | chalcone-synthase (chs) activity was followed during the development of primary leaves of oat (avena sativa l.) seedlings grown under different illumination conditions. continuous darkness and continuous light resulted in similar time courses of enzyme activity. the maximum of chs activity in etiolated leaves was delayed by 1 d and reached about half the level of that of light-grown leaves. in seedlings grown under defined light-dark cycles a diurnal rhythm of chs activity and its protein level ... | 1991 | 24193751 |
| prediction of f3 row performance from f2 individual plant data in oats. | parameters estimated from a gardner-eberhart analysis of the f2 generation of a six-parent diallel in oats (avena sativa l.) were used to compare methods for predicting the performance of f3 row plots. the prediction methods were: (1) individual f2 plant performance (f2i), (2) parent average plus f2 plot deviations (pf2), (3) parent average plus weighted f2 plot deviations (pf2p), (4) best linear unbiased prediction (blup) of parent average plus f2 plot deviations (bpf2), and (5) blup plus weigh ... | 1991 | 24221162 |
| elongation growth of the leaf sheath base of avena sativa seedlings: regulation by hormones and sucrose. | the leaf sheath base of the seedling of avena sativa was characterized for growth response to hormones and sucrose. six day old plants, raised under a 10:14 hr light:dark cycle, were excised at the coleoptilar node and 1 cm above the node for treatment. the growth of the leaf sheath base was promoted by gibberellic acid (ga3) and this response was dose dependent. the lag to response initiation was approximately 4 hr. growth with or without ga3 (10 micromoles) was transient, diminishing appreciab ... | 1991 | 11538405 |
| dynamics of auxin movement in the gravistimulated leaf-sheath pulvinus of oat (avena sativa). | the role of auxin redistribution in the graviresponse of the leaf-sheath pulvinus of oat (avena sativa l.) was assessed using 3h-indole-3-acetic acid (3h-iaa) preloaded into isolated pulvini. when pulvini were totally isolated from subtending nodal tissue as well as leaf-sheath and internode, gravistimulation failed to induce an asymmetric growth response. presence of either the nodal tissue or the internode/leaf-sheath tissue was sufficient to restore a normal graviresponse. gravistimulation of ... | 1991 | 11538277 |
| the outer epidermis of avena and maize coleoptiles is not a unique target for auxin in elongation growth. | a controversy exists as to whether or not the outer epidermis in coleoptiles is a unique target for auxin in elongation growth. the following evidence indicates that the outer epidermis is not the only auxin-responsive cell layer in either avena sativa l. or zea mays l. coleoptiles. coleoptile sections from which the epidermis has been removed by peeling elongate in response to auxin. the magnitude of the response is similar to that of intact sections provided the incubation solution contains bo ... | 1991 | 11538125 |
| the ph profile for acid-induced elongation of coleoptile and epicotyl sections is consistent with the acid-growth theory. | the acid-growth theory predicts that a solution with a ph identical to that of the apoplast of auxin-treated tissues (4.5.-5.0) should induce elongation at a rate comparable to that of auxin. different ph profiles for elongation have been obtained, however, depending on the type of pretreatment between harvest of the sections and the start of the ph-incubations. to determine the acid sensitivity under in vivo conditions, oat (avena sativa l.) coleoptile, maize (zea mays l.) coleoptile and pea (p ... | 1991 | 11538124 |
| characterization of acyllipid: sterol glucoside acyltransferase from oat (avena sativa l.) seedlings. | membranous fractions from leaves of oat seedlings readily convert cholesterol beta-d-glucoside into its 6'-o-acyl derivative using endogenous acyllipids as acyl sources. experiments with delipidated enzyme preparations showed that among acyllipids present in oat leaves digalactosyldiacylglycerols are evidently the best acyl donors in this reaction. beside of sterol glucosides, the enzyme can acylate beta-d-glucosides of several other steroids, although at very different rates. | 1991 | 1796705 |
| an h-atpase assay: proton pumping and atpase activity determined simultaneously in the same sample. | a continuous spectrophotometric assay of h(+)-atpase activity was developed by combining two well-known methods for measuring proton pumping and atpase activity. proton uptake into plasma membrane vesicles from avena sativa l. (cv rhiannon) was monitored as the absorbance decrease at 495 nm of the deltaph probe acridine orange. simultaneously, atpase activity was measured by following the absorbance decrease at 340 nanometers by coupling atp hydrolysis enzymatically to the oxidation of nadh. thi ... | 1990 | 16667867 |
| cell wall and enzyme changes during the graviresponse of the leaf-sheath pulvinus of oat (avena sativa). | the graviresponse of the leaf-sheath pulvinus of oat (avena sativa) involves an asymmetric growth response accompanied by several asymmetric processes, including degradation of starch and cell wall synthesis. to understand further the cellular and biochemical events associated with the graviresponse, changes in cell walls and their constituents and the activities of related enzymes were investigated in excised pulvini. asymmetric increases in dry weight with relatively symmetric increases in wal ... | 1990 | 11537483 |
| aluminum ions induce oat protoplasts to produce an extracellular (1-->3)beta-d-glucan. | aluminum chloride induced mesophyll protoplasts of oat (avena sativa) to produce an extracellular polysaccharide (eps). eps induced by alcl(3) appeared identical to that produced in response to the phytotoxin victorin (jd walton, ed earle [1985] planta 165: 407-415). al ions at 1 millimolar were toxic to protoplasts, but maximum eps production occurred at a sublethal concentration of 200 micromolar, assayed at ph 6.0. as measured by incorporation of [(14)c]glucose, alcl(3) stimulated eps product ... | 1990 | 16667679 |
| immunocytolocalization of plasma membrane h-atpase. | the localization of plasma membrane h(+)-atpase has been studied at the optical microscope level utilizing frozen and paraffin sections of avena sativa and pisum sativum, specific anti-atpase polyclonal antibody, and second antibody coupled to alkaline phosphatase. in leaves and stems the atpase is concentrated at the phloem, supporting the notion that it generates the driving force for phloem loading. in roots the atpase is concentrated at both the periphery (rootcap and epidermis) and at the c ... | 1990 | 16667670 |
| pectin esterification is spatially regulated both within cell walls and between developing tissues of root apices. | monoclonal antibodies recognizing un-esterified (jim5) and methyl-esterified (jim7) epitopes of pectin have been used to locate these epitopes by indirect immunofluorescence and immunogold electron microscopy in the root apex of carrot (daucus carota l.). both antibodies labelled the walls of cells in all tissues of the developing root apex. immunogold labelling observed at the level of the electron microscope indicated differential location of the pectin epitopes within the cell walls. the un-e ... | 1990 | 24196931 |
| photoregulation of beta-tubulin mrna abundance in etiolated oat and barley seedlings. | the effect of light on the abundance of beta-tubulin mrna was measured in etiolated avena sativa l. and hordeum vulgare l. seedlings. slot blot analysis employing an oat beta-tubulin cdna clone was used to measure beta-tubulin mrna levels. white light induced a 45% decrease in oat beta-tubulin mrna abundance by 2 hours after transfer. a saturating red light pulse induced 40 and 55% decreases in beta-tubulin mrna levels in oats and barley, respectively. recovery of beta-tubulin mrna levels was ob ... | 1990 | 16667578 |
| intracellular protein phosphorylation in oat (avena sativa l.) protoplasts by phytochrome action: involvement of protein kinase c. | phosphorylations of two proteins (27 kda, 32 kda) in oat cells were dependent on phytochrome action. to determine which kinase system(s) for the phosphorylation of these two proteins are controlled by the phytochrome, involvement of the ca2+/dg dependent protein kinase (protein kinase c) was first investigated. when a protein kinase c inhibitor (1-(5-isoquinoline sulfonyl)-2-methylpiperazine:h-7) or the inositol phospholipid metabolic blocker li+ was added into the cell suspension, respectively, ... | 1990 | 2163631 |
| co-ordination of chromophore-apoprotein synthesis in the developing leaf of avena sativa l. | | 1990 | 2373249 |
| [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 ... | 1990 | 2390226 |
| 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 ... | 1990 | 24232678 |
| 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. | 1990 | 16667347 |
| 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 ... | 1990 | 16667337 |
| 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 ... | 1990 | 24202016 |
| 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 ... | 1990 | 16667279 |
| genomic sequence of a 12s seed storage protein gene from oat (avena sativa l. cv. 'solidor'). | | 1990 | 2326176 |
| 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 ... | 1990 | 16667250 |
| oscillations of acetylcholine in oat seedlings. | using gas chromatography it was shown that acetylcholine (ach) was present in both etiolated and green oat (avena sativa l. cv. diadem) seedlings. in etiolated seedlings the ach level was low, but increased rapidly during exposure to sunlight and red light (rl). the stimulative influence of rl was reversed by far-red light (frl). the rl- and frl- changes in ach level were correlated to changes in acetylcholinesterase (ache) localization. using karnovsky's method, it was found that in the etiolat ... | 2013 | 2350987 |
| 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 ... | 1989 | 24213051 |
| 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 ... | 1989 | 16667176 |
| 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 ... | 1989 | 16667096 |
| 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, ... | 1989 | 2535531 |
| 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 ... | 1989 | 24227154 |
| 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 ... | 1989 | 16666960 |
| 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 ... | 1989 | 16666935 |
| 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 ... | 1989 | 2751674 |
| 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 ... | 1989 | 16666844 |
| 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 ... | 1989 | 16453890 |
| 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 ... | 1989 | 24212898 |
| 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 ... | 1989 | 24212749 |
| 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 ... | 1989 | 24212745 |
| 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 ... | 1989 | 24212743 |
| 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 ... | 1989 | 24212553 |
| 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 ... | 1989 | 16666736 |
| 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. ... | 1989 | 16666733 |
| 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 ... | 1989 | 24212493 |
| 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 ... | 1989 | 16666708 |
| 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 ... | 1989 | 16666699 |
| 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 ... | 1989 | 2727087 |
| 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 ... | 1989 | 11541033 |
| 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 ... | 1989 | 11539809 |
| 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 ... | 1989 | 11537452 |
| 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 ... | 1989 | 11537448 |
| 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 ... | 1989 | 2541117 |
| 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 ... | 1988 | 16666419 |
| 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 ... | 1988 | 2463784 |
| 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, ... | 1988 | 2903155 |
| 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 ... | 1988 | 24220772 |
| 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 ... | 1988 | 16666391 |
| 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 ... | 1988 | 16666377 |
| 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 ... | 1988 | 11538847 |
| 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 ... | 1988 | 2463467 |
| 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 ... | 1988 | 24277097 |
| 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 ... | 1988 | 24221928 |
| 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 ... | 1988 | 16666294 |
| 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 ... | 1988 | 16666275 |
| 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 ... | 1988 | 16666253 |
| 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. ... | 1988 | 24221713 |
| 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 ... | 1988 | 16666211 |
| 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 ... | 1988 | 16666210 |
| 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 ... | 1988 | 16666207 |
| 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 ... | 1988 | 16593951 |
| 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 ... | 1988 | 16666179 |
| 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 ... | 1988 | 16666164 |
| 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 ... | 1988 | 16666131 |
| 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 ... | 1988 | 16666102 |
| 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 ... | 1988 | 16666073 |
| 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 ... | 1988 | 16665998 |