| 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 ... | 1988 | 2891708 |
| 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 ... | 1988 | 24226183 |
| 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 ... | 1988 | 15092555 |
| 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 ... | 1988 | 11537872 |
| 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 ... | 1987 | 24226075 |
| 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, ... | 1987 | 24225921 |
| 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 ... | 1987 | 24225916 |
| 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 ... | 1987 | 16665762 |
| 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 ... | 1987 | 24240224 |
| 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 ... | 1987 | 24225792 |
| 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 ... | 1987 | 16665655 |
| 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 ... | 1987 | 24225705 |
| 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 ... | 1987 | 17246394 |
| 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 ... | 1987 | 16665440 |
| 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 ... | 1987 | 16665435 |
| 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 ... | 1987 | 16665375 |
| 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 ... | 1987 | 28312237 |
| 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 ... | 1987 | 24232968 |
| 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 ... | 1987 | 16665303 |
| 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) > ... | 1987 | 16665276 |
| comparison of the protein conformations between different forms (pr and pfr) of native (124 kda) and degraded (118/114 kda) phytochromes from avena sativa. | | 1987 | 3562595 |
| 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 ... | 1987 | 24232877 |
| 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. | 1987 | 15092702 |
| 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 ... | 1987 | 11539098 |
| 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 ... | 1986 | 24248196 |
| 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 ... | 1986 | 24232327 |
| 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 ... | 1986 | 16665016 |
| 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 ... | 1986 | 11539102 |
| photobiology of phytochrome-mediated growth responses in sections of stem tissue from etiolated oats and corn. | the far-red reversibility of the phytochrome-controlled stimulation of elongation of coleoptile sections by low fluence red light has been characterized in subapical coleoptile sections from dark-grown avena sativa l., cv lodi seedlings. the fluence dependence of the far-red reversal was the same whether or not the very low fluence response is also expressed. the capacity of far-red light to reverse the red light-induced response began to decline if the far-red light was given more than 90 minut ... | 1986 | 16664851 |
| kinetics of intracellular redistribution of phytochrome in avena coleoptiles after its photoconversion to the active, far-red-absorbing form. | the kinetics of the intracellular redistribution of phytochrome (sequestering) in avena sativa l. coleoptiles following a brief, saturating actinic pulse of red (r) light have been determined. immunocytochemical labelling of phytochrome with monoclonal antibodies showed that at 22°c sequestering can occur within 1-2 s from the onset of r irradiation and is dependent upon the continued presence of the far-red-absorbing form of phytochrome (pfr). the initial rate, but not the final extent, of sequ ... | 1986 | 24240300 |
| viscosity dependence of primary photoprocesses of 124 kilodalton phytochrome. | to characterize the nature of primary photoprocesses of phytochrome which serves as the red-far red reversible photoreceptor for photomorphogenesis in plants, viscosity dependence of the fluorescence lifetimes of phytochrome isolated from etiolated oat seedling (avena sativa l.) has been investigated. the fluorescence decay of phytochrome exhibited approximately two components, one with lifetime in the range of 50-70 ps and another with 1.1-1.2 ns in phosphate buffer with or without 40-67% glyce ... | 1986 | 19431669 |
| tissue-distribution of secondary phenolic biosynthesis in developing primary leaves of avena sativa l. | primary leaves of oats (avena sativa l.) have been used to study the integration of secondary phenolic metabolism into organ differentiation and development. in particular, the tissue-specific distribution of products and enzymes involved in their biosynthesis has been investigated. c-glucosylflavones along with minor amounts of hydroxycinnamic-acid esters constitute the soluble phenolic compounds in these leaves. in addition, considerable amounts of insoluble products such as lignin and wall-bo ... | 1986 | 24241851 |
| allelopathic effects ofcitrus aurantium l. : i. vegetational patterning. | field observations on undisturbed stands of sour orange revealed thatcynodon dactylon, chenopodium album, avena sativa, andamaranthus retroflexus were not able to grow normally and complete their life cycles under its canopies, although the same species grow well under adjacent trees of date palm. investigations revealed that the failure of the test species to grow normally under sour orange was not due to competition for light, moisture and minerals or to differences in soil texture or ph. soil ... | 1985 | 24311244 |
| activities of arginine and ornithine decarboxylases in various plant species. | in extracts from the youngest leaves of avena sativa, hordeum vulgare, zea mays, pisum sativum, phaseolus vulgaris, lactuca sativa, and four pyrrolizidine alkaloid-bearing species of heliotropium, the activities of ornithine decarboxylase, close to v(max), ranged between traces and 1.5 nanomoles per hour per gram fresh weight when based on putrescine formed during incubation with labeled ornithine. the arginine decarboxylase activities in the same extracts ranged between 8 and 8000 nanomoles per ... | 1985 | 16664442 |
| assaying ornithine and arginine decarboxylases in some plant species. | a release of (14)co(2) not related to ornithine decarboxylase activity was found in crude leaf extracts from lycopersicon esculentum, avena sativa, and especially from the pyrrolizidine alkaloid-bearing heliotropium angiospermum when incubated with [1-(14)c]- or [u-(14)c]ornithine. the total (14)co(2) produced was about 5- to 100-fold higher than that due to ornithine decarboxylase activities calculated from labeled putrescine (put) found by thin-layer electrophoresis in the incubation mixtures. ... | 1985 | 16664441 |
| physiological mechanism of the auxin-induced increase in light sensitivity of phytochrome-mediated growth responses in avena coleoptile sections. | the physiology of the auxin-induced 10,000-fold increase in light sensitivity of a phytochrome-mediated growth response (shinkle and briggs, 1984 proc natl acad sci usa 81: 3742-3746) has been characterized in subapical coleoptile sections from dark-grown oat (avena sativa l. cv lodi) seedlings. six micromolar indole-3-acetic acid (iaa) must be present for 1 hour before to 2 hour after irradiation in order to confer maximal sensitivity to light. the direct effect of iaa on growth can be separate ... | 1985 | 16664413 |
| effect of calmodulin antagonists on auxin-induced elongation. | coleoptile segments of oat (avena sativa var cayuse) and corn (zea mays l. var patriot) were incubated in different concentrations of calmodulin antagonists in the presence and absence of alpha-naphthaleneacetic acid. the calmodulin antgonists (chlorpromazine (cp), trifluoperazine, and fluphenazine) inhibited the auxin-induced elongation at 5 to 50 micromolar concentrations. chlorpromazine sulfoxide, an analog of chlorpromazine, did not have significant effect on the elongation of oat and corn c ... | 1985 | 16664387 |
| chloroplast biogenesis 49 : differences among angiosperms in the biosynthesis and accumulation of monovinyl and divinyl protochlorophyllide during photoperiodic greening. | various angiosperms differed in their monovinyl and divinyl protochlorophyllide biosynthetic capabilities during the dark and light phases of photoperiodic growth. some plant species such as cucumis sativus l., brassica juncea (l.) coss., brassica kaber (dc.) wheeler, and portulaca oleracea l. accumulated mainly divinyl protochlorophyllide at night. monocotyledonous species such as avena sativa l., hordeum vulgare l., triticum secale l., zea mays l., and some dicotyledonous species such as phase ... | 1985 | 16664351 |
| stimulation of extracellular polysaccharide synthesis in oat protoplasts by the host-specific phytotoxin victorin. | the host-specific phytotoxin victorin (hv-toxin) stimulates mesophyll protoplasts of susceptible but not of resistant oat (avena sativa l.) to produce an amorphous, ethanol-insoluble extracellular material which stains with calcofluor white and aniline blue. over a 24-h period incorporation of [(14)c]glucose into ethanol-insoluble products is maximally stimulated by 60 pg victorin/ml, whereas at 6 ng/ml initial rates of incorporation are higher but the protoplasts collapse. the extracellular mat ... | 1985 | 24241147 |
| characterization of developing oat seed mrna: evidence for many globulin mrnas. | polyadenylated mrna from developing oat (avena sativa l.) seeds was isolated and analyzed. prominent mrna species of 18s, 15s and 12s were observed; the 18s mrna was judged to be esentially free of ribosomal rna by hybridization analysis. size fractionation andin vitro translation of this mrna was performed. sds, ief-sds gel electrophoresis and immunoprecipitation were used to analyze the translation products. it is shown that globulin mrna (18s) accounts for roughly 30% of the total mrna in dev ... | 1985 | 24310836 |
| the role of separate molecular domains in the structure of phytochrome from etiolated avena sativa l. | the spectral properties of peptides generated from etiolated-avana, 124-kda (kilodalton) phytochrome by endogenous protease(s) have been studied to assess the role of the amino-terminal and the carboxyl-terminal domains in maintaining the proper interaction between protein and chromophore. the amino-terminal, 74-kda chromopeptide, a degradation product of the far-red absorbing form of the pigment (pfr), is shown to be spectrally similar to the 124-kda, undegraded molecule. the minimum and maximu ... | 1985 | 24248223 |
| sodium and potassium fluxes and compartmentation in roots of atriplex and oat. | k(+) and na(+) fluxes and ion content have been studied in roots of atriplex nummularia lindl. and avena sativa l. cv goodfield grown in 3 millimolar k(+) with or without 3 or 50 millimolar nacl. compartmental analysis was carried out with entire root systems under steady-state conditions.increasing ambient na(+) concentrations from 0 to 50 millimolar altered k(+), in atriplex, as follows: slightly decreased the cytoplasmic content (q(c)), the vacuolar content (q(v)), and the plasma membrane inf ... | 1985 | 16664273 |
| electrostatic surface properties of plasmalemma vesicles from oat and wheat roots. ion binding and screening investigated by 9-aminoacridine fluorescence. | right-side-out and sealed plasmalemma vesicles were isolated from roots of spring wheat (triticum aestivum l. cv. drabant) and oat (avena sativa l. cv. brighton) by two-phase partition in a medium containing sucrose (0.25 mol l(-1)). oat root plasmalemma vesicles were discovered to contain a strongly fluorescent compound with an emission maximum at 418 nm. the surface potential of the membranes was monitored by 9-aminoacridine fluorescence and the effect of protein concentration, mannitol versus ... | 1985 | 24249604 |
| immunochemical detection with rabbit polyclonal and mouse monoclonal antibodies of different pools of phytochrome from etiolated and green avena shoots. | while two monoclonal antibodies directed to phytochrome from etiolated oat (avena sativa l.) shoots can precipitate up to about 30% of the photoreversible phytochrome isolated from green oat shoots, most precipitate little or none at all. these results are consistent with a report by j.g. tokuhisa and p.h. quail (1983, plant physiol. 72, suppl., 85), according to which polyclonal rabbit antibodies directed to phytochrome from etiolated oat shoots bind only a small fraction of the phytochrome obt ... | 1985 | 24249602 |
| phytochrome in green tissue: spectral and immunochemical evidence for two distinct molecular species of phytochrome in light-grown avena sativa l. | a method is described for the extraction of phytochrome from chlorophyllous shoots of avena sativa l. poly(ethyleneimine) and salt fractionation are used to reduce chlorophyll and to increase the phytochrome concentration sufficiently to permit spectral and immunochemical analyses. the phototransformation difference spectrum of this phytochrome is distinct from that of phytochrome from etiolated shoots in that the maximum in the red region of the difference spectrum is shifted about 15 nm to a s ... | 1985 | 24249601 |
| proteolysis of endogenous substrates in senescing oat leaves : i. specific degradation of ribulose bisphosphate carboxylase. | proteolysis of ribulose bisphosphate carboxylase (rubpcase) during senescence was monitored using oat leaf segments (avena sativa cv victory), kept in the dark. we here report the development of a novel approach for measuring protein degradation of endogenous substrates both in situ and in vitro in crude extracts using specific antibodies against highly purified polypeptides. the proteolytic products were separated on sodium dodecyl sulfate-gels. they were then electrotransferred onto nitrocellu ... | 1985 | 16664184 |
| spectral characterization and proteolytic mapping of native 120-kilodalton phytochrome from cucurbita pepo l. | a spectral, immunochemical, and proteolytic characterization of native 120-kilodalton (kd) phytochrome from cucurbita pepo l. is presented and compared with that previously reported for native 124-kd phytochrome from avena sativa. the molecule was partially purified ( approximately 200-fold) in the phytochrome-far red-absorbing form (pfr) in the presence of the protease inhibitor, phenylmethylsulfonyl fluoride, using a modification of the procedure initially developed to purify 124-kd avena phyt ... | 1985 | 16664177 |
| homology between legumin-like polypeptides from cereals and pea. | the presence of legumin-like constituents within the globulin fractions of wheat (triticum aestivum), rye (secale cereale) and corn (maize, zea mays) was demonstrated. two-dimensional analysis of wheat globulins in the presence and absence of a reducing agent revealed the existence of reducible approximately 60 kda polypeptides. western-blot analysis with 125i-labelled antibodies raised against the oat (avena sativa) 12s globulin holoprotein or its alpha-subunits demonstrated, firstly, the immun ... | 1985 | 3985947 |
| inhibition of phytochrome synthesis by gabaculine. | gabaculine (5-amino-1,3-cyclohexadienylcarboxylic acid), a transaminase inhibitor, also inhibits chlorophyll formation in plants, and the effect of this compound can be counteracted by 5-aminolevulinic acid (ala) (flint, personal communication, 1984). since it is probable that ala also serves as a precursor to phytochrome, the effects of gabaculine on phytochrome synthesis in developing etiolated seedlings were examined using in vivo spectrophotometry. preemergence treatment with gabaculine was ... | 1985 | 16664094 |
| investigations into the possible regulation of negative gravitropic curvature in intact avena sativa plants and in isolated stem segments by ethylene and gibberellins. | using avena sativa l. cv. victory oat seedlings and excised p-1 stem segments (including the p-1 and p-2 internodes) the effect of exogenously supplied ethylene and the removal of ethylene on internodal extension and gravitropic bending was assessed. similarly, the ability of the excised system to respond to gravistimulation was assessed in the presence of inhibitors of ethylene action (agno3) and ethylene synthesis (3,5-diiodo-4-hydroxybenzoic acid and benzyl isothiocyanate; bitc). the producti ... | 1985 | 11540850 |
| polyamine levels as related to growth, differentiation and senescence in protoplast-derived cultures of vigna aconitifolia and avena sativa. | we have previously reported that aseptically cultured mesophyll protoplasts of vigna divide rapidly and regenerate into complete plants, while mesophyll protoplasts of avena divide only sporadically and senesce rapidly after isolation. we measured polyamine titers in such cultures of vigna and avena, to study possible correlations between polyamines and cellular behavior. we also deliberately altered polyamine titer by the use of selective inhibitors of polyamine biosynthesis, noting the effects ... | 1985 | 11539806 |
| sterols in seeds and leaves of oats (avena sativa l.). | in seeds and leaves of oats (avena sativa l.) 12 different sterols (cholesterol, cholstanol, δ(7)-cholestenol, campesterol, campestanol, stigmasterol, lophenol, sitosterol, stigmastanol, δ(5)-avenasterol, δ(7)-avenasterol and δ(7)-stigmastenol) have been identified. the sterol pattern is qualitatively the same, but the relative composition is different in leaves and in seeds. leaves contain mainly sitosterol, stigmasterol, cholesterol and campesterol, but only minor portions of avenasterols. see ... | 1984 | 24253572 |
| a quantitative simulation model for h-amino acid cotransport to interpret the effects of amino acids on membrane potential and extracellular ph. | the h(+) cotransport of neutral and acidic amino acids induces transient depolarizations of oat coleoptile (avena sativa l., var victory) plasma membranes. the depolarizations, which are completed within 1 or 2 minutes, are followed by repolarizations that are nearly completed within another 2 or 3 minutes. cysteine induced a two-phased alkalinization of the tissue free space during the electrical changes. the first phase was a rapid, linear increase in ph that coincided with the depolarization; ... | 1984 | 16663928 |
| monoclonal antibodies to three separate domains on 124 kilodalton phytochrome from avena. | forty-six monoclonal antibodies have been prepared against 124 kilodalton phytochrome from avena sativa cv garry. clones grown in mice have yielded ascites fluids with antibodies which bind to three distinct regions of the molecule, as visualized by immunoblot analysis of proteolytically produced peptides of the protein. one antibody group (type 1) recognizes an antigenic domain(s) that lies within 6 kilodaltons of the amino terminus of the molecule, a region critical to correct protein-chromoph ... | 1984 | 16663895 |
| anion-sensitive, h-pumping atpase of oat roots : direct effects of cl, no(3), and a disulfonic stilbene. | to understand the mechanism and molecular properties of the tonoplast-type h(+)-translocating atpase, we have studied the effect of cl(-), no(3) (-), and 4,4'-diisothiocyano-2,2'-stilbene disulfonic acid (dids) on the activity of the electrogenic h(+)-atpase associated with low-density microsomal vesicles from oat roots (avena sativa cv lang). the h(+)-pumping atpase generates a membrane potential (deltapsi) and a ph gradient (deltaph) that make up two interconvertible components of the proton e ... | 1984 | 16663870 |
| redox activity at the surface of oat root cells. | electron transport activity at the cell surface of intact oat seedlings (avena sativa l. cv garry) was examined by measuring the oxidation and/or reduction of agents in the medium bathing the roots. oxidation of nadh with or without added electron acceptors and reduction of ferricyanide by an endogenous electron donor were detected. the activities appear to be due to electron transfer at, or across, the plasma membrane and not due to reagent uptake or leakage of oxidants or reductants. nadh-ferr ... | 1984 | 16663850 |
| physiological control of arginine decarboxylase activity in k-deficient oat shoots. | the effect of k-deficiency on the putrescine biosynthetic enzyme, arginine decarboxylase (adc), was investigated by growing oat (avena sativa l. var victory) plants on a low-k, but otherwise complete nutrient medium in washed quartz sand for up to 18 days. enzyme activity rose as the concentration of kcl was dropped to 0.6 millimolar or below. however, growth was not inhibited significantly at 0.6 millimolar kcl. adc activity increased in the whole shoot of k-deficient oats throughout the period ... | 1984 | 16663842 |
| intracellular transport and posttranslational cleavage of oat globulin precursors. | the synthesis, transport, and posttranslational processing of reserve globulin in avena sativa l. seeds were studied by pulse-chase labeling. developing oat seeds were labeled with radioactive sulfate and tissue homogenates were used for globulin extraction.two globulin precursors (58-62 kilodaltons) were labeled after 1 hour pulse. the alpha and beta globulin subunits appeared between 2 and 10 hours later, while simultaneously the 58 to 62 kilodaltons polypeptides gradually disappeared. this co ... | 1984 | 16663789 |
| cell fusion by simulated atmospheric discharges: further support for the hypothesis of involvement of electrofusion in evolution. | electrofusion of mesophyll cell protoplasts of avena sativa was induced by simulated atmospheric discharges. it is shown both experimentally and theoretically that the potential differences which occur at quite long distances from the point of lightning stroke are large enough to induce fusion. besides electromagnetic waves which are emitted during lightning (g. küppers and u. zimmermann, febs lett. 164, 323 (1983] cell fusion may have also occurred directly by means of the voltage built-up on t ... | 2016 | 6516538 |
| determination of compartmented metabolite pools by a combination of rapid fractionation of oat mesophyll protoplasts and enzymic cycling. | in vivo pool sizes of a range of metabolites have been determined in subcellular fractions of darkened and illuminated mesophyll protoplasts of avena sativa l. these estimations were made by combining a method of rapid protoplast fractionation with enzymic cycling techniques. results are given for reduced and oxidized pyridine nucleotides, triose phosphates, 3-phosphoglycerate, inorganic phosphate, aspartate, malate, oxaloacetate, glutamate, 2-oxoglutarate, and citrate, from chloroplasts, mitoch ... | 1984 | 16663726 |
| inhibition of gravitropism in oat coleoptiles by the calcium chelator, ethyleneglycol-bis-(beta-aminoethyl ether)-n,n'-tetraacetic acid. | a treatment period as brief as 8 h in 10(-3) m egta completely blocks gravitropism in 70-80% of the treated coleoptiles of oats (avena sativa l. cv. garry) without inhibiting growth. only about 10% of the plants perfused in water failed to exhibit gravitropism. subsequent perfusion of egta-treated plants with calcium completely restores gravitropism; post-perfusion with water does not. after perfusion in water for 10 h, gravistimulated oat coleoptile segments show the same asymmetry of 45ca dist ... | 1984 | 11829020 |
| biosynthesis of jasmonic acid by several plant species. | six plant species metabolized (18)o-labeled 12-oxo-cis,cis-10,15-phytodienoic acid (12-oxo-pda) to short chain cyclic fatty acids. the plant species were corn (zea mays l.), eggplant (solanum melongena l.), flax (linum usitatissimum l.), oat (avena sativa l.), sunflower (helianthus annuus l.), and wheat (triticum aestivum l.). among the products was jasmonic acid, a natural plant constituent with growth-regulating properties. the pathway is the same as the one recently reported by us for jasmoni ... | 1984 | 16663643 |
| indole-3-acetic acid sensitization of phytochrome-controlled growth of coleoptile sections. | addition of 6 mum indole-3-acetic acid (iaa) to incubation buffer increases the sensitivity of coleoptile sections cut from dark-grown avena sativa l. cv. lodi to red light by a factor of 10,000, relative to the response in the absence of added iaa, without changing the maximum amount of light-induced growth. from 0.03 to 4 mum iaa sections show at least a 100-fold increase in sensitivity to red light relative to the response in the absence of added iaa. in this iaa concentration range, the ligh ... | 1984 | 16593476 |
| native phytochrome: immunoblot analysis of relative molecular mass and in-vitro proteolytic degradation for several plant species. | the relative molecular mass (mr) of the native phytochrome monomer from etiolated cucurbita pepo l., pisum sativum l., secale cereale l. and zea mays l. seedlings has been determined using immunoblotting to visualize the chromoprotein in crude extracts subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. a single phytochrome band is observed for each plant species when the molecule is extracted under conditions previously demonstrated to inhibit the proteolysis of native avena ... | 1984 | 24258779 |
| the instron technique as a measure of immediate-past wall extensibility. | the relationship between the plastic-extensibility values (pex) obtained in the instron technique and the growth parameter, wall extensibility (φ) has been evaluated for avena sativa l. coleoptile cell walls. the possibility that pex is proportional to the growth rate rather than to φ has been eliminated by showing that turgor-driven changes in the growth rate do not cause comparable changes in pex. for avena coleoptiles, pex appears to be a measure of the average φ over the previous 60-90 min r ... | 1984 | 24258778 |
| glyoxylate transamination in intact leaf peroxisomes. | intact spinach (spinacia oleracea l.) leaf peroxisomes were supplied with glycolate and one to three of the amino acids serine, glutamate, and alanine, and the amount of the respective alpha-keto acids formed in glyoxylate transamination was assayed. at 1 millimolar glycolate and 1 millimolar each of the three amino acids in combination, the transamination reaction reached saturation; reduction of either glycolate or amino acid concentration decreased the activity. the relative serine, glutamate ... | 1984 | 16663603 |
| characterization of oat vicilin-like polypeptides. | the 7s and 3s globulin fractions were extracted and characterized from avena sativa l. seeds which showed similar solubility characteristics and holoprotein size to those of the vicilin fraction in legumes. these holoproteins were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectrofocussing, and two-dimensional electrophoresis. among the components of the oat reserve globulins, the 7s fraction was capable of binding to concanavalin a-sepharose, thus indicating ... | 1984 | 16663577 |
| purification, characterization, and kinetic mechanism of s-adenosyl-l-methionine: vitexin 2"-o-rhamnoside 7-o-methyltransferase of avena sativa l. | an o-methyltransferase catalyzing the transfer of the methyl group of s-adenosyl-l-methionine to the a-ring 7-hydroxyl group of vitexin 2"-o-rhamnoside has been isolated from oat primary leaves and purified 180-fold by protein fractionation with (nh4)2so4 and chromatography on deae-cellulose and s-adenosyl-l-homocysteine-sepharose. km values for s-adenosyl-l-methionine and the flavonoid substrate were 1.6 microm and 15 microm, respectively. the lack of methyltransfer to biosynthetic intermediate ... | 1984 | 6705789 |
| discrimination between the red- and far-red-absorbing forms of phytochrome from avena sativa l. by monoclonal antibodies. | a set of rat monoclonal antibodies (arc mac 48 to 52 and 54 to 56), raised to phytochrome from dark-grown seedlings of avena sativa l. was tested for the ability to discriminate between the red-absorbing (pr) and far-red-absorbing (pfr) forms of phytochrome by indirect enzyme-linked immunosorbent assay. mac 50 bound more strongly to pfr and mac 49 and 52 showed preferential binding to pr from extracts of dark-grown avena seedlings; mac 50 also bound more strongly to pfr from brushite-purified ph ... | 1984 | 24258587 |
| quantitation of oat globulin by radioimmunoassay. | a radioimmunoassay was used to determine the globulin content of developing oat (avena sativa l. var coker 6622) seeds. the globulin content increased from 0.32 to 2.37 milligrams per seed from 2 to 21 days post anthesis. the amount of globulin did not increase from 21 to 30 days post anthesis. when the total protein of seeds harvested 21, 24, and 30 days post anthesis was measured by micro-kjeldahl analysis, it was determined to be 3.15 milligrams per seed for each sampling date. when the amoun ... | 1984 | 16663443 |
| auxin concentration/growth relationship for avena coleoptile sections from seedlings grown in complete darkness. | a biphasic auxin dose-response curve has been obtained for indole-acetic acid (iaa)-stimulated growth of subapical sections of coleoptiles from totally dark-grown oats (avena sativa l. cv lodi). the curve for growth at 6 h is composed of a log-linear phase and a modified bell-shaped phase separated by a plateau. the curve is log-linear from 0.003 to 0.4 micromolar iaa when sections are incubated in ph 5.9 buffer. the plateau of iaa concentration-neutral growth is seen from 0.4 to 4.0 micromolar ... | 1984 | 16663419 |
| characterization by enzyme-linked immunosorbent assay of monoclonal antibodies to pisum and avena phytochrome. | nine monoclonal antibodies to pea (pisum sativum l.) and 16 to oat (avena sativa l.) phytochrome are characterized by enzyme-linked immunosorbent assay against phytochrome from six different sources: pea, zucchini (cucurbita pepo l.), lettuce (lactuca sativa l.), oat, rye (secale cereale l.), and barley (hordeum vulgare l.). all antibodies were raised against phytochrome with a monomer size near 120,000 daltons. nevertheless, none of them discriminated qualitatively between 118/114-kilodalton oa ... | 1984 | 16663365 |
| phytochrome quantitation in crude extracts of avena by enzyme-linked immunosorbent assay with monoclonal antibodies. | an enzyme-linked immunosorbent assay (elisa), which uses both rabbit polyclonal and mouse monoclonal antibodies to phytochrome, has been adapted for quantitation of phytochrome in crude plant extracts. the assay has a detection limit of about 100 pg phytochrome (<1 fmol of monomer) and can be completed within 10 h. nonspecific interference by crude plant extracts was detected and corrected for. quantitation of phytochrome in crude extracts of etiolated oat (avena sativa l.) seedlings by elisa ga ... | 1983 | 24258330 |
| role of endoplasmic reticulum in biosynthesis of oat globulin precursors. | oat (avena sativa l.) groats were labeled with radioactive leucine and salt-soluble proteins were extracted and analyzed. polyacrylamide gel electrophoresis followed by fluorography indicated two radioactive polypeptides with molecular weight 58 to 62 kilodaltons which were similar in size to unreduced globulin alpha-beta dimers. the role of endoplasmic reticulum in the synthesis of these globulin polypeptides was investigated by in vivo and in vitro protein synthesis studies. labeled tissue was ... | 1983 | 16663349 |
| separation of two types of electrogenic h-pumping atpases from oat roots. | microsomal vesicles of oat roots (avena sativa var lang) were separated with a linear dextran (0.5-10%, w/w) or sucrose (25-45%, w/w) gradient to determine the types and membrane identity of proton-pumping atpases associated with plant membranes. atpase activity stimulated by the h(+)/k(+) exchange ionophore nigericin exhibited two peaks of activity on a linear dextran gradient. atpase activities or atp-generated membrane potential (inside positive), monitored by scn(-) distribution, included a ... | 1983 | 16663344 |
| stereospecific analysis of triglycerides of glycine max, glycine soya, avena sativa and avena sterilis strains. | a rapid method for the stereospecific analysis of triglycerides based on enzymatic hydrolysis on thin layer plates was applied to a number of glycine max, glycine soya, avena sativa and avena sterilis strains. the percentage of each fatty acid on the sn-1-, sn-2- and sn-3-positions was linearly related to the total percentage of the fatty acid in the triglyceride. large deviations from the common triglyceride pattern were not found. | 1983 | 6686643 |
| compartmentation of labeled fixation products in intact mesophyll protoplasts from avena sativa l. after in-situ inhibition of the chloroplast phosphate translocator. | leaf mesophyll protoplasts of oat (avena sativa l.) were allowed to fix (14)c-labeled bicarbonate in the absence or presence of pyridoxal phosphate (plp), a specific inhibitor of the phosphate translocator of the inner envelope membrane of chloroplasts. the incubation was terminated by a method of rapid integrated protoplast homogenization and fractionation, and compartmented levels of label contained in sugars, phosphate esters, amino acids and organic acids were determined. the results show th ... | 1983 | 24258228 |
| rapid response of the plasma-membrane potential in oat coleoptiles to auxin and other weak acids. | we have compared the effects of the auxin, indole-3-acetic acid (iaa) with that of other weak acids on the plasma-membrane potential of oat (avena sativa l.) coleoptile cells. cells treated with 1 μm iaa at ph 6 depolarize 20-25 mv in 10-12 min, but they then repolarize, until by 20-25 min their potentials are about 25 mv more negative than the initial value. similar concentrations of benzoic and butyric acids cause the initial depolarization, but not the subsequent hyperpolarization. the hyperp ... | 1983 | 24258173 |
| interaction of indoleacetic acid and gibberellic acid in the short-term growth kinetics of oat stem segments. | gibberellins and auxins are the only hormones known that promote growth in oat (avena sativa) stem segments, but when applied together, indoleacetic acid inhibits gibberellic acid-induced growth appreciably. this study shows that in addition to this inhibitory role, indoleacetic acid shortens the response time of the tissue to gibberellic acid. | 1983 | 16663259 |
| differential changes in the amount of protein complexes in the chloroplast membrane during senescence of oat and bean leaves. | antibodies against the individual subunits of protein complexes in the chloroplast membranes were used to follow the amounts of these polypeptides during foliar senescence. no change was found in the amount of polypeptides of photosystem i reaction center and the chloroplast coupling factor during senescence of oat (avena sativa l.) and bean (phaseolus vulgaris l.) leaves. a significant decrease in the amount of the different components of the cytochrome b(6)-f complex was detected. this change ... | 1983 | 16663247 |
| differences in the physical properties of native and partially degraded phytochrome as probed by their differential sensitivity to permanganate oxidation. | the differential sensitivities to permanganate oxidation of the red and far-red forms of native phytochrome from avena sativa l. cv mulaga (isolated as pfr from red-irradiated tissue) and of partially degraded phytochrome (isolated as pr from nonirradiated tissue) were determined. the far-red absorbing form of partially degraded phytochrome was 5 times more sensitive than its red-absorbing form, while both the far-red and red forms of native phytochrome exhibited identical sensitivity. the prese ... | 1983 | 16663241 |
| translocation and metabolism of endosperm-applied [2-c] indoleacetic acid in etiolated avena sativa l. seedlings. | the role of free indole-3-acetic acid (iaa) in the endosperm of avena sativa l. seedlings was investigated to determine its contribution to free iaa in the shoot. [2-(14)c]iaa was injected into the endosperm of darkgrown seedlings and the transport and metabolism of the [(14)c]-labeled compounds determined. it was concluded that translocation of free iaa directly from the endosperm is probably not a significant source of free iaa in the shoot, mainly because even small amounts of [(14)c]iaa intr ... | 1983 | 16663214 |
| structure-function studies on phytochrome. preliminary characterization of highly purified phytochrome from avena sativa enriched in the 124-kilodalton species. | a new protocol for the purification of phytochrome from etiolated avena sativa l. seedlings in 15-25% yield is described. this preparation exhibits molecular properties dissimilar to those previously reported from oats. phytochrome prepared by this method contains a dominant species having a mr = 124,000 (70% of total) on sodium dodecyl sulfate-polyacrylamide gels, in addition to a chromoprotein species with mr = 118,000 (30%). a blocked nh2 terminus is indicated by amino acid sequencing of the ... | 1983 | 6885811 |
| a study of homoeologous relationships in the cultivated oat avena sativa (2n=6x=42). | the homoeologous relationship of the chromosomes of the allopolyploid species avena sativa has been demonstrated by studies of nullisomic-tetrasomic compensation. the effects of the deletion of chromosome vi was partially compensated for by a tetrasomic dose of chromosome xiii, both at the gametic and zygotic level. the data confirm the genetic similarities of the homoeologues, which are attributable to their evolutionary derivation from a common chromosome. | 1983 | 24263931 |
| a report on the consumption, composition and nutritional adequacy of a mixture of lush green perennial ryegrass (lolium perenne) and cocksfoot (dactylis glomerata) fed ad libitum to thoroughbred mares. | non-pregnant thoroughbred mares were stabled and subjected to 2 trials, each 24 h in duration, to establish their total consumption of a mixture of freshly cut, lush green perennial ryegrass (lolium perenne) and cocksfoot (dactylis glomerata) in approximately equal proportions; and to compare the total intake of crude protein, calcium, phosphorus and mass of the grass mixture on a dry matter basis with their daily nutritional requirements. the body mass of each mare was calculated at the commenc ... | 1983 | 6655653 |
| production and purification of monoclonal antibodies to pisum and avena phytochrome. | at least nine monoclonal antibodies against phytochrome from pisum sativum l. and 20 against phytochrome from avena sativa l. have been obtained from mouse hybridomas that were produced by fusion of spleen cells with sp 2/o-ag14 myeloma cells. hybridomas were selected and cloned in a single step by plating on a semisolid methylcellulose medium. eight antibodies to pisum and one to avena phytochrome were immunopurified from hybridoma medium or ascitic fluid. when necessary, secreted antibodies we ... | 1983 | 24264758 |
| differential uptake of mercury vapor by gramineous c(3) and c(4) plants. | the uptake of mercury vapor by six gramineous plant species was compared under uniform conditions using a whole-plant chamber and (203)hg-labeled mercury at a low atmospheric concentration. mean hg uptake by leaves of the c(3) species oats (avena sativa), barley (hordeum vulgare), and wheat (triticum aestivum) was 5 times greater than that by leaves of the c(4) species corn (zea mays), sorghum (sorghum bicolor), and crabgrass (digitaria sanguinalis). although there was a difference in resistance ... | 1983 | 16663117 |
| phytochrome-mediated cellular photomorphogenesis. | red light-induced cell elongation and division in intact, etiolated oat (avena sativa cv lodi) seedlings have been assessed. the middle of coleoptile was especially responsive in the very low fluence range whereas the region immediately below the coleoptile tip and the two regions just above the coleoptilar node were more responsive than the entire organ in the low fluence range. these responses in the coleoptile are both the result of an increase in cell elongation. coleoptile cell division is ... | 1983 | 16663071 |
| relation between respiration and senescence in oat leaves. | the respiration of excised oat (avena sativa cv victory) leaves and their sensitivity to inhibitors was followed during senescence under varied conditions. the respiration rate, which in controls reaches its peak on the third day in darkness, is lowered at the time of fastest loss of chlorophyll (as reported earlier) by seven unrelated reagents that all delay dark senescence. when senescence is delayed by white light or by cytokinins, the respiratory rise is correspondingly delayed. kinetin and ... | 1983 | 16663039 |
| role of o(2) and mitochondrial respiration in a photosynthetic stimulation of oat protoplast acidification of a surrounding medium. | some photosynthetically stimulated acidification of the medium by oat (avena sativa l. cv garry) leaf protoplasts required respiration. the requisite respiration (a) had a low apparent affinity for o(2), (b) was blocked by cyanide plus salicylhydroxamic acid, (c) characterized protoplasts and mitochondria isolated from protoplasts, (d) could be induced in leaf segments, and (e) appeared to result from an inhibition of mitochondrial respiration that included the cytochrome pathway.carbon monoxide ... | 1983 | 16663006 |
| light-stimulated changes in the acidity of suspensions of oat protoplasts: dependence upon photosynthesis. | light induced an alkalinization and stimulated a subsequent acidification of the medium surrounding oat (avena sativa l. cv garry) leaf protoplasts. blue light was less effective than would be predicted from photosynthetic action spectra. nonetheless, 3-(3,4-dichlorophenyl)-1,1-dimethylurea prevented alkalinization and reduced acidification to the dark rate for protoplast suspensions exposed to all light regimes tested.alkalinization increased in parallel with initial rates of o(2) evolution as ... | 1983 | 16663005 |
| cellular and subcellular localization of calcium in gravistimulated oat coleoptiles and its possible significance in the establishment of tropic curvature. | light-and electron-microscopic studies of the distribution of calcium in gravitropically responding oat (avena sativa l. cv. "garry") coleoptiles are described. a modification of the antimonate precipitation procedure was used to localize tissue calcium in situ. an accumulation of ca in the upper halves of horizontal, gravistimulated coleoptiles is seen within 10 min of stimulus onset. a pronounced redistribution of ca to the upper side occurs within 30 min; although the localization of this cat ... | 1983 | 24264412 |
| light-induced breakdown of nadph-protochlorophyllide oxidoreductase in vitro. | light-induced loss of the enzyme protochlorophyllide reductase (ec 1.6.99.1.), already described as a characteristic of whole plants, has now been demonstrated in vitro using etioplast membrane preparations of avena sativa l. var peniarth and secale cereale l. var rheidol. some evidence is presented, based upon temperature, ph, and inhibitor sensitivity of the process, that loss of enzyme may be the result of proteolysis. the light-induced process can, in vitro, be largely prevented by addition ... | 1983 | 16662967 |
| oat seed globulin: subunit characterization and demonstration of its synthesis as a precursor. | the predominant storage protein of oat (avena sativa l.) seeds is a saline-soluble globulin with a mol wt of 320,000 which is composed of six large (m(r) = 35,000 to 40,000) and six small (m(r) = 20,000 to 25,000) subunits. experiments were conducted to further describe the subunit polypeptides and to identify the initial translation products of globulin mrnas. approximately 20 large subunits and 10 small subunits were resolved by two-dimensional gel analysis. the large and small subunits had ac ... | 1983 | 16662952 |
| analysis of phytochrome kinetics in light-grown avena sativa l. seedlings. | the phytochrome content, the rate of phytochrome accumulation after a light/dark transition and the rate of phytochrome destruction after a 1.5 d reaccumulation period in darkness were measured in light grown avena sativa l. seedlings. the results using spectrophotometrical methods (norflurazon treated seedlings) and the radio-immunoassay (ria) (green seedlings) were almost identical. the rate of phytochrome synthesis was analysed by measuring the activity of poly(a(+))-rna coding for the phytoc ... | 1983 | 24264335 |
| aminotransfer from alanine and glutamate to glycine and serine during photorespiration in oat leaves. | (15)n-labeled glutamate and alanine were used to examine the photorespiratory nitrogen metabolism in oat (avena sativa l.) leaf slices. glutamate and alanine supply amino groups for glycine formation during photorespiration. the nitrogen flux from alanine to glycine was estimated to be 3 times higher than that from glutamate. it is concluded from these results that alanine is a direct and important amino donor for photorespiratory glycine formation in oat leaves. the (15)n labeling of serine was ... | 1983 | 16662936 |
| putrescine and acid stress : induction of arginine decarboxylase activity and putrescine accumulation by low ph. | incubation of peeled oat avena sativa l. var victory leaf segments on media of ph 5.0 or below leads to a rapid and massive increase in the titer of putrescine while incubation at ph values above 5.0 causes little or no change. the low ph effect is independent of the buffer system employed. putrescine levels rise within 3 hours and reach their peak 8 to 9 hours after acidification. at this time, putrescine titer is eight times greater at ph 3.5 than at 6.0. none of the other polyamines shows a r ... | 1983 | 16662904 |
| anion-sensitive, h-pumping atpase in membrane vesicles from oat roots. | h(+)-pumping atpases were detected in microsomal vesicles of oat (avena sativa l. var lang) roots using [(14)c]methylamine distribution or quinacrine fluorescent quenching. methylamine (mea) accumulation into vesicles and quinacrine quench were specifically dependent on mg,atp. both activities reflected formation of a proton gradient (deltaph) (acid inside) as carbonyl cyanide m-chlorophenylhydrazone, nigericin (in the presence of k(+)), or gramicidin decreased mea uptake or increased quinacrine ... | 1983 | 16662875 |
| isolation and characterization of oat aleurone and starchy endosperm protein bodies. | to compare oat (avena sativa l. cv froker) aleurone protein bodies with those of the starchy endosperm, methods were developed to isolate these tissues from mature seeds. aleurone protoplasts were prepared by enzymic digestion and filtration of groat (caryopsis) slices, and starchy endosperm tissue was separated from the aleurone layer by squeezing slices of imbibed groats followed by filtration. protein bodies were isolated from each tissue by sucrose density gradient centrifugation. ultrastruc ... | 1983 | 16662859 |
| metabolism of oat leaves during senescence : vii. the interaction of carbon dioxide and other atmospheric gases with light in controlling chlorophyll loss and senescence. | in air largely freed from co(2), senescence of isolated oat (avena sativa cv victory) seedling leaves is no longer prevented by white light; instead, the leaves lose both chlorophyll and protein as rapidly as in the dark. senescence in light is also accelerated in pure o(2), but it is greatly delayed in n(2); 100% n(2) preserves both protein and chlorophyll in light and in darkness. in light in air, most of the compounds tested that had previously been found to delay or inhibit senescence in dar ... | 1983 | 16662800 |