Publications

reversible redistribution of phytochrome within the cell upon conversion to its physiologically active form.	the intracellular localization of phytochrome was seen in dark-grown oat (avena sativa l., cv. garry) and rice (oryza sativa l., cv. unknown) shoots after various light treatments using an indirect peroxidase-antiperoxidase antibody labeling method. phytochrome is generally distributed throughout the cytoplasm in cells of tissue that had not been exposed to light prior to fixation. within, at most, 8 min after the onset of saturating red irradiation, phytochrome, now present in the far-red-absor ...	1975	1093170
studies on the presence of adenosine cyclic 3':5'-monophosphate in oat coleoptiles.	the incorporation of adenosine-8-(14)c into adenosine cyclic 3':5'-monophosphate in coleoptile-first leaf segments of avena sativa l. was investigated. homogenates of segments incubated in adenosine-8-(14)c for either 4 or 10 hours were partially purified by thin layer chromatography followed by paper electrophoresis. a radioactive fraction, less than 0.06% of the (14)c present in the original homogenate, migrated as adenosine cyclic 3':5'-monophosphate during electrophoresis. upon treatment wit ...	1975	16659080
immunological and physical characterization of the products of phytochrome proteolysis.	the relationship between high molecular weight (large) and low molecular weight (small) forms of phytochrome has been shown earlier to be one of proteolysis. the products of such proteolysis are characterized here by chromatography through bio-gel p-200 using specific antiphytochrome sera as an assay system. degradation of large oat (avena sativa l. cv. garry) phytochrome as phytochrome, red-absorbing form, phytochrome, far red-absorbing form, or under cycling conditions in crude preparations co ...	1975	16659053
[light-mediated de-novo synthesis of δ-aminolaevulinate dehydratase in isolated avena etioplasts].	a light dependent increase of the activity of δ-aminolaevulinate dehydratase (e.c. 4.2.1.24) in isolated etioplasts of avena sativa l. was shown. this increase can be assumed to be due to a de-novo synthesis of the enzyme. chloramphenicol was found to inhibit this synthesis, whereas cycloheximide did not have any effect. illumination with red light (660 nm) was followed by the same increase of porphobilinogen production as illumination with white light; far-red (731 nm) did not induce such an ef ...	1975	24435263
effects of magnesium, calcium and lanthanum ions on stomatal oscillations in avena sativa l.	mg(2+), ca(2+) and la(3+) caused an increased period time of the transpiratory oscillations when given to excised oscillating avena plants (plants without root system). the effect was reversible, i.e. after withdrawal of the ions the period time returned to its original value. in order to achieve the same period lengthening as with 2.5 mm la(3+), 20 mm ca(2+) and 40 mm mg(2+) was needed. the effects are discussed along two lines: (a) the ions interfere with ionic processes, central for the stoma ...	1975	24435179
developmental changes in the surface properties of chloroplast membranes.	when the surface properties of etioplast and etiochloroplast membranes from dark grown or variously illuminated leaves of avena sativa l. are examined by counter current distribution in a dextran: poly(ethylene-glycol) two-phase system the results may be summarized as follows: (i) etioplast membranes consist of two main classes with respect to upper phase poly(ethylene-glycol) affinity. (ii) shortly after illumination the proportion of higher affinity membranes increases and the upper phase affi ...	1975	24430083
plasma membrane adenosine triphosphatase of oat roots: activation and inhibition by mg and atp.	atpase activity of plasma membrane vesicles isolated from oat (avena sativa l. cv. goodfield) roots was examined in the presence of various concentrations of mgcl(2) and atp. a mg(2+): atp ratio of about 1 was required for maximal activity regardless of the concentrations used; the optimum concentration for both mg(2+) and atp was 9 mm. based on the atpase activity at different concentrations of complexed mg.atp and free atp, it is concluded that mg.atp is the true substrate of this enzyme.under ...	1975	16659034
multiple forms of invertase in developing oat internodes.	three different invertases are found in the developing internodes of oat (avena sativa cv. victory). two soluble invertases (i and ii) are separable on diethylaminoethylcellulose and sephadex columns. they are further distinguished by their kinetic constants, heat stability, and differences in stability and apparent activity optima in response to ph treatments. relative activities of the two soluble isozymes change considerably during the developmental stages examined. invertase i activity rises ...	1975	16659014
red light-enhanced phytochrome pelletability: re-examination and further characterization.	red light-enhanced pelletability of phytochrome was observed in extracts of all 11 plants tested: avena sativa l., secale cereale l., zea mays l., cucurbita pepo l., sinapis alba l., pisum sativum l., helianthus anuus l., raphanus sativus l., glycine max (l.) merr., phaseolus vulgaris l., and lupinus albus l. this enhanced pelletability was observed in all 11 plants following in situ irradiation (in vivo binding) but only in sinapis and cucurbita after irradiation of crude extracts (in vitro bin ...	1976	16659745
pharmacotherapy with avena sativa - a double blind study.	hundred non-hospitalized smokers with an average consumption of 20 cigarettes per day were treated with an alcoholic extract of avena sativa for disaccustoming. the study was double blind. by using query-sheets personal contact was excluded. the first result was a placebo-effect of 35% for disaccustoming of smokers and no statistically significant effect of the extract of avena sativa. the second result was a difference of disaccustoming between light and heavy smokers. it was shown, that the ra ...	1976	794001
characterization of passive ion transport in plasma membrane vesicles of oat roots.	the passive influx and efflux of inorganic ions across plasma membrane vesicles purified from extracts of avena sativa roots were investigated. uptake was measured by incubating the vesicles in a radioisotope for various times. the "loaded" vesicles were separated from the external solution by gel filtration. efflux was measured by dialyzing the preloaded vesicles.ion transport was differentiated from superficial ion binding by (a) the time course of association of radioisotope with the vesicles ...	1976	16659668
lack of influence of phytochrome on membrane permeability to tritiated water.	the water permeability of tissues was investigated by measuring the efflux of (3)hho from previously loaded (in darkness) etiolated bean buds (phaseolus vulgaris l. var. red kidney), pea epicotyl segments (pisum sativum l. var. alaska), and oat coleoptile segments (avena sativa l. var. garry). red light, far red light, or darkness was applied at the time of transfer of tissue from labeled to unlabeled medium. there were no effects of light on half-time for efflux or on the maximum level of radio ...	1976	16659447
polypeptide binding to plastid envelopes during chloroplast development.	pulse-chase experiments using [(35)s]methionine with various light and dark regimes have been used to follow in situ polypeptide accumulation during plastid development in avena sativa (var. mostyn). subsequent isolation and later fraction of the etioplasts, etio-chloroplasts or chloroplasts into envelope, stroma lamellae, thylakoid and supernatant (stromal) fractions has enabled a survey of the movement of label between the different fractions. these studies show that considerable and sometimes ...	1976	24430904
changes in envelope permeability during chloroplast development.	the permeability of the plastid envelope during the development of avena sativa plastids was investigated by light scattering and uptake of various labelled compounds (malate, succinate, glutamate, α-ketoglutarate, citrate, glycine, sucrose). the results presented show that a primary event during greening is a change in permeability, thereby allowing an increased transport of metabolites across the membranes of very early etio-chloroplast stages. the results are discussed in view of an adaption ...	1976	24430818
phytochrome control of electrical potentials and intercellular coupling in oat-coleoptile tissue.	microelectrodes were used to demonstrate two electrical responses which occur in oat (avena sativa l.) coleoptile parenchyma-cells during exposure to red light. the membrane potential of these cells depolarized 5-10 mv in several seconds in red light and repolarized more slowly in far-red light. by pulsing current through the cells, it was found that cellular coupling along the longitudinal axis of the coleoptile increased about 2-fold in red light, but that coupling along the lateral axis was n ...	1976	24424904
cell elongation in the grass pulvinus in response to geotropic stimulation and auxin application.	horizontally-placed segments of avena sativa l. shoots show a negative geotropic response after a period of 30 min. this response is based on cell elongation on the lower side of the leaf-sheath base (pulvinus). triticum aestivum l., hordeum vulgare l. and secale cereale l. also show geotropic responses that are similar to those in avena shoots. the pulvinus is a highly specialized organ with radial symmetry and is made up of epidermal, vascular, parenchymatous and collenchymatous tissues. stato ...	1976	24424826
fluxes of gibberellic and abscisic acids, together with that of adenosine 3',5'-cyclic phosphate, across plastid envelopes during development.	application of the technique of silicone oil centrifugation to etioplasts and etio-chloroplasts isolated from greening etiolated avena sativa l. laminae has shown that etioplast envelope membranes are relatively impermeable to gibberellic acid, abscisic acid and adenosine 3',5'-cyclic phosphate. however, there is a marked increase in permeability for all in the early stages of greening, particularly after 2 h. all fluxes are reduced thereafter but a high level of abscisic acid still remains.	1976	24424702
changes in the permeability of the inner mitochondrial membrane associated with plastid development.	mitochondria isolated from greening etiolated laminae of avena sativa l. show changes in the permeability of their inner membranes during chloroplast development similar to those described earlier for plastids. oxalo-acetate, succinate and α-keto-glutarate permeate most readily inner membranes of mitochondria isolated from laminae given 2 h illumination whilst glutamate and glycine show later and more general penetration into the matrix spaces of mitochondria from greening tissue. aminolevulinic ...	1976	24424690
movement of labelled metabolites from mitochondria to plastids during development.	the exchange of metabolites from isolated mitochondria of avena sativa l. to isolated etioplasts or 1-24 h etio-chloroplasts, from the same laminae, has been investigated. the results confirm the synchronised changes in the permeabilities of the inner membranes of each during plastid development. they also indicated the possibility of directed transport of certain metabolites from mitochondria to plastids especially during the early stages of chloroplast maturation. over 80% of labelled succinat ...	1976	24424689
binding of (45)ca (2+) to particulate fractions of coleoptile tissue.	using recently developed techniques, we have investigated the binding of (45)ca(2+) to membrane preparations from corn (zea mays l) and oat (avena sativa l) coleoptile tissue. scatchard plot analysis reveals at least two ca(2+)-binding sites in each tissue, a high affinity binding site (k m=7.7×10(-7) m, n=6.9×10(-10) mol·0.5 g f.w.(-1) in corn, k m=4.93×10(-6) m, n=2.29×10(-9) mol·0.5 g f.w.(-1) in avena) and a low affinity binding site (k m=9.01×10(-5) m, n=5.4×10(-8) mol·0.5 g f.w.(-1) in cor ...	1976	24424643
[light dependence of phytol accumulation. a contribution to the question of chlorophyll biosynthesis].	phytol is identified by gas chromatography and mass spectrometry and its concentration determined (range 0.005-3 μg) in darkgrown and irradiated plants. seeds of oats (avena sativa l.), wheat (triticum aestivum l.) and barley (hordeum vulgare l.) contain bound phytol (2-5 μg/g). the phytol content decreases during germination in the dark. phytol synthesis in dark-grown seedlings starts in the light and stops in the dark again. the degradation of phytol in the dark is much slower than that of chl ...	1976	24424592
inhibition of iaa-induced elongation in avena coleoptile segments by lead: a physiological and an electron microscopic study.	a high resolution growth measuring apparatus was used to demonstrate the inhibition of auxin-induced cell elongation in oat coleoptile segments (avena sativa l. var holden) by lead at concentrations ranging from 2 x 10-6 m to 2 x 10-3 m. the inhibition was immediate, having no measurable lag period. electron micrographs of lead-treated and control segments revealed that in the treated material, lead became localized as electron-dense granules in the cell walls and in vesicles associated with dic ...	1976	1001018
extraction and purification of a substance with luteinizing hormone releasing activity from the leaves of avena sativa.	attempts were made to purify the lh-releasing substance extracted from the leaves of avena sativa by means of two-step chromatographic procedures using a weakly acidic ion-exchange resin (cg-50,type ii) and deae-sephadex a-25 (coarse) with successful results. for preliminary fractionation of such starting materials as dried leaves, fresh leaves, and acetone-extracted powder(crude extracts), 5% acetate-buffered active carbon proved to be more effective than starch zone electrophoresis. from its b ...	1976	781913
attempts to detect cyclic adenosine 3':5'-monophosphate in higher plants by three assay methods.	endogenous levels of cyclic adenosine-3':5'-monophosphate in coleoptile first leaf segments of oat (avena sativa l.), potato (solanum tuberosum l.) tubers, tobacco (nicotiana tabacum l.) callus, and germinating seeds of lettuce (lactuca sativa l.) were measured with a modified gilman binding assay and a protein kinase activation assay. the incorporation of adenosine-8-(14)c into compounds with properties similar to those of cyclic amp was also measured in studies with germinating lettuce seeds. ...	1976	16659419
long distance translocation of sucrose, serine, leucine, lysine, and carbon dioxide assimilates: ii. oats.	to establish whether several amino acids were equally able to enter the phloem of oat (avena sativa l.) plants and be transported, several (14)c-labeled amino acids were applied individually to an abraded spot on a fully expanded source leaf. the base of an immature sink leaf was monitored with a gm tube for time and rate of arrival of radioactivity. transport of (14)c-sucrose and (14)co(2) assimilates was measured for a comparison. the applied l-serine, l-lysine, and l-leucine, as well as sucro ...	1977	16659821
use of i-labeled phytochrome to quantitate phytochrome binding to membranes of avena sativa.	purified oat phytochrome was labeled with (125)i without altering the photoreversibility or absorbance properties of the pigment. the radiolabeled phytochrome was used in experiments in vitro to quantitate the binding of the pigment to both crude and purified membrane preparations from oat tissue. after the membranes were allowed to react with (125)i-labeled phytochrome, washed free of unbound material, and pelleted, they were found to have significant levels of radioactivity bound to them. qual ...	1977	16592450
formation of n-acetylglutamate by extracts of higher plants.	the enzymic synthesis of n-acetylglutamate was studied in extracts of higher plant tissues, especially in sugar beet leaves (beta vulgaris l.). sugar beet leaves had an enzyme that transferred the acetyl group either from acetyl-coa or from n(2)-acetylornithine to glutamate. the enzyme was so unstable that special precautions were necessary for its detection and appreciable purification was impossible. the km values were 2.5 and 0.025 mm for acetyl-coa and n(2)-acetylornithine, respectively. the ...	1977	16659918
comparison of three methods for measuring electrical resistances of plant cell membranes.	the reliability of two different membrane resistance-measuring methods that use a single intracellular microelectrode was tested against a conventional method that uses two intracellular microelectrodes. the first single-electrode method used a single square current pulse and required a constant microelectrode resistance. this method was unreliable because the electrode resistance changed markedly on cell penetration and changed with time within the cell. the second method used a high frequency ...	1977	16660164
beta-d-glucan of avena coleoptile cell walls.	a specific glucanase was used to liberate a noncellulosic beta-d-glucan from isolated cell walls of avena sativa coleoptile tissue. cell walls of this tissue contain as much as 7 to 9 mg of glucan/100 mg of dry wall. because of the specific action pattern of the enzyme, a linkage sequence of.. 1 --> 4 glc 1 --> 3 glc 1 --> 4 glc.. is indicated and the predominance of trisaccharide and tetrasaccharide as hydrolytic products suggests a rather regular repeating pattern in the polysaccharide. the tr ...	1977	16660149
stabilization of oat leaf protoplasts through polyamine-mediated inhibition of senescence.	protoplasts isolated from avena sativa l. leaves undergo progressive senescence when incubated aseptically in 0.6 m mannitol with or without added nutrients. this senescence is manifested by morphological deterioration and ultimate lysis of protoplasts, by a decrease in incorporation of [(3)h]uridine and [(3)h]leucine into macromolecules, and by a sharp increase in ribonuclease activity.the presence in the incubation medium of l-arginine, l-lysine, certain polyamines related to these amino acids ...	1977	16660139
occurrence and properties of polygalacturonase in avena and other plants.	polygalacturonase activity has been detected in a number of plants including seedlings of phaseolus vulgaris, zea mays, avena sativa, and pisum sativum. particular emphasis was placed on characterizing the enzyme from oat seedlings. this enzyme is solubilized by 0.2 m nacl, and its activity is highest near the apical tips of oat coleoptiles. it has a ph optimum between 5 and 5.5 and is activated by ca(2+), with an optimal concentration of 0.4 mm. cd(2+) also activates the enzyme but less effecti ...	1977	16660135
isolation and purification of an alpha-mannosidase from coleoptiles of avena sativa.	an alpha-mannosidase has been purified from the coleoptiles of avena sativa l. var. segrehavre. the enzyme, which is tightly associated with the cell wall, was solubilized with 3 m licl. the purification involves precipitation with (nh(4))(2)so(4), gel filtration, ion exchange chromatography, and isoelectric focusing. the enzyme appears homogeneous when chromatographed on disc gels and on isoelectric focusing gels. the enzyme runs as a single protein of constant specific activity when chromatogr ...	1977	16660119
responses of enzymically isolated aleurone cells of oat to gibberellin a(3).	oat (avena sativa l.) aleurone layer cells (spheroplasts) were isolated by maceration of the aleurone layer with a mixture of commercially available cellulase and pectinase. about 20% of the cells present in intact layers were released as spheroplasts and 79 +/- 9% of the spheroplast population was viable as judged by methylene blue staining. the spheroplasts became disorganized in solutions containing less than 0.4 md-mannitol. when the spheroplasts were incubated for 48 hours, total activities ...	1977	16660114
effects of indoleacetic acid on the quantity of mitochondria, microbodies, and plastids in the apical and expanding cells of dark-grown oat coleoptiles.	we determined the number of mitochondria, microbodies, and plastids in dark-grown oat (avena sativa) coleoptiles following incubation in indoleacetic acid (iaa) for a period of 60 minutes at 6-minute intervals. in the apical outer epidermis of coleoptiles, the mitochondria increased from 31.4 to 35 per cell section with a 6-minute incubation in iaa, and this trend persisted over the 60-minute incubation. neither the microbodies, plastids, nor the dicytosomes (gawlik and miller 1974 plant physiol ...	1977	16660086
chloroplast phosphofructokinase: i. proof of phosphofructokinase activity in chloroplasts.	ammonium sulfate fractionation of an extract from the leaves of spinach (spinacia oleracea l.) produced two fractions of phosphofructokinase activity, the first stimulated by inorganic phosphate and the second inhibited by inorganic phosphate. only the second fraction was obtained from similar treatment of an extract of isolated spinach chloroplasts. the two fractions differed distinctly with respect to kinetics for the substrate fructose 6-phosphate. evidence for these two types of phosphofruct ...	1977	16660078
proteases of senescing oat leaves: i. purification and general properties.	two proteases active in the senescing first leaves of oat seedlings (avena sativa cv. victory) have been purified approximately 500-fold by a combination of ammonium sulfate precipitation, affinity chromatography on hemoglobin-sepharose, and ion exchange chromatography on deae-sephadex. the enzymes show ph optima of 4.2 and 6.6 with denatured hemoglobin as substrate, and the molecular weights of both are about 76,000. their optimum temperatures are close to 50 c. small amounts of a third enzyme, ...	1977	16659993
occurrence of a high temperature sensitivity of chloroplast ribosome formation in several higher plants.	a specific high temperature-induced deficiency of chloroplast ribosome formation, as indicated by the absence of chloroplast rrna, has been observed in the leaves of light- or dark-grown seedlings of avena sativa l., hordeum vulgare l., and triticum aestivum l. at certain temperatures between 28 and 34 c. while the growth of the leaves (size, morphology, total amino nitrogen content) was little affected by the elevated temperature, chlorophyll accumulation was strongly inhibited, amounting to on ...	1977	16659957
cell-free synthesis of globulin by developing oat (avena sativa l.) seeds.	the primary storage protein synthesized during oat (avena sativa l.) groat development is a globulin. polysomes were isolated from oat groats 12 days after anthesis. these polysomes directed the incorporation of radioactive amino acids into protein in a cell-free protein synthesis system containing wheat germ supernatant. the mg(2+) optimum was 4 mm, the ph optimum was 6-8, and the amount of amino acid incorporation depended on polysome concentration. incorporation of amino acids was linear for ...	1977	16659952
selectivity of alkali cation influx across the plasma membrane of oat roots: cation specificity of the plasma membrane atpase.	influx of alkali cations (li(+), na(+), k(+), rb(+), cs(+)) across plasma membranes of cells of excised roots of avena sativa cv. goodfield was selective, but different, in the absence and in the presence of 1 mm caso(4). ca(2+) reduced the influx rates of all of the alkali cations-especially na(+) and li(+). transport selectivity changed as the external concentrations of the alkali cations increased.plasma membrane atpase, purified from avena sativa roots, was differentially stimulated by alkal ...	1977	16659910
phytochrome-controlled hydrogen ion excretion by avena coleoptiles.	a red light-induced, far red reversible stimulation of proton efflux from apical segments of etiolated avena sativa l. cv. victory coleoptiles was observed. the acidification responses to red light and also to auxin were not the consequence of respired co(2). the response to red light was strongly inhibited by cycloheximide and carbonyl cyanide, m-chlorophenyl hydrazone, but mannitol had a stimulatory effect. red light and auxin applied together yielded a greater than additive response, in compa ...	1977	16659904
metabolism of oat leaves during senescence: v. senescence in light.	a comparison has been made of the progress of senescence in the first leaf of 7-day-old oat plants (avena sativa cv. victory) in darkness and in white light. light delays the senescence, and intensities not over 100 to 200 ft-c (1000-2000 lux) suffice for the maximum effect. in such intensities, chlorophyll loss and amino acid liberation still go on in detached leaves at one-third to one-half the rate observed in darkness; however, when the leaves are attached to the plant, the loss of chlorophy ...	1977	16659871
osmotic shock inhibits auxin-stimulated acidification and growth.	cells of oat coleoptiles (avena sativa l. cv. "garry") have been osmotically shocked in order to observe the effect of alterations of the plasma membrane on some auxin responses. when coleoptile sections were treated sequentially with 0.5 m mannitol and 1 mm na-phosphate (ph 6.4) at 4 c, polar auxin transport and acidification by 1 mm cacl(2) were unaffected, but auxin-stimulated acidification and growth were eliminated. shock treatment also had no effect on acid-stimulated growth or on freezing ...	1977	16659853
effects of osmotic shock on some membrane-regulated events of oat coleoptile cells.	oat coleoptile sections (avena sativa l. cv. "garry") were osmotically shocked with 0.5 m mannitol followed by 1 mm na-phosphate (ph 6.4) at 4 c. this treatment reduced uptake of alpha-aminoisobutyric acid, 3-o-methyl glucose, and leucine by 75 to 90% but inhibited (36)cl(-) uptake only 30%. some recovery was observed 1 to 3 hours later. respiration rates were unaffected by osmotic shock and protein synthesis was reduced 11%.osmotic shock also stimulated efflux of alpha-aminoisobutyric acid and ...	1977	16659852
superoxide dismutases: ii. purification and quantitative relationship with water-soluble protein in seedlings.	superoxide dismutase was purified from pea (pisum sativum l., cv. wando) seeds and corn (zea mays l., cv. michigan 500) seedlings. the purified pea enzyme eluting as a single peak from gel exclusion chromatography columns contained the three electrophoretically distinct bands of superoxide dismutase characterizing the crude extract. the purified corn enzyme eluted as the same peak as the pea enzyme, and contained five of the seven active bands found in the crude extract. the similar molecular we ...	1977	16659840
superoxide dismutases: i. occurrence in higher plants.	shoots, roots, and seeds of corn (zea mays l., cv. michigan 500), oats (avena sativa l., cv. au sable), and peas (pisum sativum l., cv. wando) were analyzed for their superoxide dismutase content using a photochemical assay system consisting of methionine, riboflavin, and p-nitro blue tetrazolium. the enzyme is present in the shoots, roots, and seeds of the three species. on a dry weight basis, shoots contain more enzyme than roots. in seeds, the enzyme is present in both the embryo and the stor ...	1977	16659839
on the localization of enzymes related to flavonoid metabolism in sections and tissues of oat primary leaves.	during growth of the primary leaves of avena sativa l., the distribution of extractable l-phenylalanine ammonia-lyase (pal, ec 4.3.1.5) and chalcone-flavanone isomerase (cfi, ec 5.5.1.6) activities in distinct leaf sections (top section, medium section and meristematic basal section) and in the epidermal and mesophyll tissues were investigated in relation to c-glycosylflavone accumulation. characteristic changes have been observed in the levels of pal and cfi activities within the three leaf sec ...	1977	24420517
distribution of chloroplast coupling factor (cf1) particles on plastid membranes during development.	samples of internal membrane systems separated from lysates of intact plastids from dark grown avena sativa l. (vars, cooba and mostyn) and hordeum vulgare l. (vars, himalaya and deba abed) given different periods of illumination before isolation were assayed for trypsin-activated ca(2+)-dependent atpase activities and also examined in the electron microscope after treatment in the manner described by oleszko and moudinanakis (1974) which assists the visualization of the chloroplast coupling fac ...	1977	24420023
initial phases of indoleacetic acid induced growth in coleoptile segments of avena sativa l.	the intial phases of auxin-induced growth in coleoptile segments of avena sativa l. were investigated using a high resolution growth recording technique, based on an angular position sensing transducer. the first response to the hormone is a slight, transient reduction of the growth rate lasting about 5 min. after this phase growth rate increases to a maximum. the duration of the increase and the maximum clearly depend on the concentration of the hormone. with increasing auxin concentration the ...	1977	24420017
the retention of photosynthetic activity by senescing chloroplasts of oat leaves.	the retention of photosystems i and ii and or rudp carboxylase activity in chloroplasts isolated from the first leaves of victory oat (avena sativa l.) seedlings was followed as the chloroplasts senesced in darkness. both photosystems (ps) i and ii retained their full activity after 3 days at 1°c, while even after 7 days at 1°c around 80% of the activity was still present. after 3 days at 25°c, ps i lost only 20% and ps ii 50% of the initial activity. acid ph increased the rate of decay of both ...	1977	24420010
examination of ribosome-like particles in isolated prolamellar bodies.	potential methods for the preparation of fractions enriched in prolamellar bodies (plbs) were examined in detail. sucrose density gradient centrifugation methods gave fractions consisting almost exclusively of plbs whilst those methods employing differential centrifugation were quite successful but contained greater quantities of lamellar membranes. greater difficulty was experienced in obtaining detached plbs which retained their "ribosome-like" lattice particles. no modification to density gra ...	1977	24419578
metabolism of indole-3-acetic acid: iv. biological properties of amino acid conjugates.	the biological activity of 20 l-alpha-amino acid conjugates of indole-3-acetic acid (iaa) to stimulate cell elongation of avena sativa coleoptile sections and to stimulate growth of soybean cotyledon tissue cultures has been examined at concentrations of 10(-4) to 10(-7)m. in the avena coleoptile test, most of the amino acid conjugates stimulated elongation. several of the conjugates stimulated as much elongation as iaa but their half-maximum concentrations tended to be higher. some of the more ...	1977	16659795
use of lipophilic cations to measure the membrane potential of oat leaf protoplasts.	uptake of the lipophilic cation triphenylmethylphosphonium into mesophyll protoplasts of oat (avena sativa l. cv. "garry") approaches equilibrium at 3 to 4 hours. the resulting external and internal concentrations are then used with the nernst equation to obtain a membrane potential of -62 millivolts, inside negative. potentials calculated in this manner are depolarized by adding 2 mm sodium azide and 50 mum carbonyl cyanide m-chlorophenylhydrazone as well as by increasing the external proton an ...	1978	16660641
phytochrome destruction: apparent inhibition by ethylene.	phytochrome destruction begins immediately following actinic irradiation of 4-day-old, dark-grown oat (avena sativa l., cv. garry) shoots grown in open containers. when grown in closed containers, otherwise identical oat shoots exhibit a delay of about 40 minutes between irradiation and the onset of destruction. this delay can be attributed to accumulation of ethylene by several criteria, including elimination of the delay by mercuric perchlorate. these data provide an explanation for otherwise ...	1978	16660639
capping structures at the 5'-terminus of polyadenylated ribonucleic acid in avena coleoptiles.	evidence is presented for the occurrence of 5'-terminal capping structures in the polyadenylated rna of oat (avena sativa) coleoptiles. these structures are composed of an inverted terminal nucleoside containing the modified base 7-methylguanine which is joined 5' to 5' with a second (penultimate) nucleoside by means of three phosphate groups in two pyrophosphate linkages. the penultimate nucleoside is joined to the remainder of the rna molecule by a conventional 3',5' phosphodiester bond. a sig ...	1978	16660619
kinetics of membrane transport during chloroplast development.	in the course of plastid development there are changes in the permeability of the envelope membranes. an investigation of the kinetics of transport with largely uncontaminated and intact etioplast/etiochloroplast preparations from greening avena sativa laminae demonstrates: (a) that etioplasts already possess specific translocators for the transporation of orthophosphate, dihydroxyacetone phosphate, 3-phosphoglycerate ("phosphate translocator"), and dicarboxylic acids ("dicarboxylate translocato ...	1978	16660596
subunit structure and composition of oat seed globulin.	oat (avena sativa l.) seed globulin was extracted from ground caryopses with 1 m nacl, 0.05 m tris(hydroxymethyl)aminoethane (ph 8.5) at room temperature. the globulin had a sedimentation constant of 12.1, and a molecular weight of 322,000, as determined by analytical ultracentrifugation. the globulin could be separated into two major subunits by sodiumdodecyl sulfate polyacrylamide gel electrophoresis. molecular weights of the subunits were 21,700 (alpha) and 31,700 (beta), and they were presen ...	1978	16660548
effect of abscisic acid on the gain of the feedback loop involving carbon dioxide and stomata.	gains of the feedback loops involving intercellular co(2) concentration on one hand, and co(2) assimilation and stomata on the other (= assimilation loop with gain [g(a)] and conductance loop with gain [g(g)]) were determined in detached leaves of amaranthus powelli s. wats., avena sativa l., gossypium hirsutum l., xanthium strumarium l., and zea mays in the absence and presence of 10(-5)m (+/-) abscisic acid (aba) in the transpiration stream. determinations were made for an ambient co(2) concen ...	1978	16660528
regulation of glucose metabolism and cell wall synthesis in avena stem segments by gibberellic acid.	gibberellic acid (ga) stimulated both the elongation of avena sativa stem segments and increased synthesis of cell wall material. the effects of ga on glucose metabolism, as related to cell wall synthesis, have been investigated in order to find specific events regulated by ga. ga caused a decline in the levels of glucose, glucose 6-phosphate, and fructose 6-phosphate if exogenous sugar was not supplied to the segments, whereas the hormone caused no change in the levels of glucose 6-phosphate, f ...	1978	16660524
cadmium alteration of root physiology and potassium ion fluxes.	segments of oat (avena sativa l.) roots which had been exposed to 1 millimolar cdso(4) in quarter-strength hoagland no. 1 solution exhibited decreased respiratory rates, atp levels, membrane-bound atpase activity, and reduced k(+) fluxes. respiration and atp levels were decreased after a 2-hour treatment with 1 millimolar cdso(4) to 65 and 75%, respectively, of control rates. a membrane-bound, mg(2+)-dependent, k(+)-stimulated acid atpase was rapidly inhibited to 12% of control activity in the p ...	1978	16660477
dual mechanisms in polyamine-mediated control of ribonuclease activity in oat leaf protoplasts.	dibasic amino acids and polyamines added to oat (avena sativa l.) leaf protoplast isolation media decrease the rnase activity of extracted protoplasts relative to controls. this effect, which is manifested even when the added polyamine is removed by exhaustive dialysis prior to assay, is due to a prevention of the rise in rnase activity which usually follows protoplast isolation. polyamines, but not dibasic amino acids, also decrease rnase activity in vitro. this in vitro effect seems to result ...	1978	16660458
evidence for amino acid-h co-transport in oat coleoptiles.	microelectrode and tracer techniques were used to test for possible amino acid-h(+) co-transport in coleoptiles of avena sativa l. cv. "garry." the amino acid analogue alpha-aminoisobutyric acid (aib) caused transient depolarization of the membrane potential. the absolute magnitude of the maximum depolarization was affected by the same factors that affected aib transport. both increased with higher concentrations of aib, increased with higher acidities in the medium, and were enhanced by indolea ...	1978	16660429
alkylguanidine inhibition of ion absorption in oat roots.	the effect of various alkylguanidines on ion absorption and energy metabolism in oat (avena sativa cv. goodfield) roots has been investigated. of several alkylguanidines tested, octylguanidine was the most effective inhibitor of both k(+) and cl(-) absorption by excised roots. at 225 mum octylguanidine, the transport of both ions was inhibited within 60 seconds and to a similar extent. octylguanidine inhibited mitochondrial oxidative phosphorylation and mitochondrial adenosine 5'-triphosphatase ...	1978	16660414
proteases of senescing oat leaves: ii. reaction to substrates and inhibitors.	two proteases isolated from senescent oat (avena sativa) leaves have been subjected to further study. one of these, an acid protease active at ph 4.2, is inhibited by phenylmethylsulfonyl fluoride (pmsf) but not by iodoacetamide (iac). the other, active at ph 6.6, is inhibited by both pmsf and iac. these results, together with previously reported evidence that mercaptoethanol stimulates the activity of only the neutral protease, are taken to indicate that the acid protease is probably of the ser ...	1978	16660324
destruction and possible de novo synthesis of phytochrome in subcellular fractions of laminae from avena sativa l.	phytochrome was determined in etiolated laminae of avena satival. either without pretreatment or after 5 min of red irradiation followed by different periods of darkness (0-24 h). at given intervals laminae were homogenized and phytochrome was determined spectrophotometrically in the total homogenate and in purified etioplasts and mitochondria. enhanced specific activity of phytochrome was found in all fractions after the irradiation in comparison to dark controls. phytochrome destruction was ob ...	1978	24414872
phytochrome photoreversibility: empirical test of the hypothesis that it varies as a consequence of pigment compartmentation.	phytochrome of oat (avena sativa l., cv. garry) coleoptile cells in the red-light-absorbing form, pr, is diffusely distributed while after conversion to the far-red-light-absorbing form, pfr, it is observed only in very small areas within the cell. comparison of phytochrome photoversibility measurements to the distribution of the pigment within the cell indicates that the spectral assay is not influenced by the observed compartmentalization of the chromoprotein. however, the observed compartment ...	1978	24414766
a comparison of regenerated cell walls in tobacco and cereal protoplasts.	four independent kinds of observations indicate that the cell wall regenerated by oat (avena sativa l.) and corn (zea mays l.) protoplasts in culture is less well developed than that regenerated by tobacco (nicotiana tabacum l.) protoplasts. following wall regeneration the cereal protoplasts remained susceptible to osmotic shock upon transfer to water, showed great enlargement, stained poorly with calcofluor white, and maintained a positive internal electrical potential. the development of a neg ...	1978	24414155
effects of fusicoccin on the activity of a key ph-stat enzyme, pep-carboxylase.	the phytotoxin fusicoccin (fc) causes rapid synthesis of malate in coleoptile tissues, presumably via phosphoenolpyruvate (pep) carboxylase coupled with malate dehydrogenase. the possibility that fc directly affects pep carboxylase in avena sativa l. and zea mays l. coleoptiles was studied and rejected. the activity of this enzyme is unaffected by fc whether fc is added in vitro or a pretreatment to the live material. fc does not change the sensitivity of the enzyme to bicarbonate or malate. the ...	1978	24414104
rapid auxin- and fusicoccin-enhanced rb(+) uptake and malate synthesis in avena coleoptile sections.	the short-term effects of auxin (indole-3-acetic acid) and fusicoccin (fc) on rb(+) uptake and malate accumulation in avena sativa l. coleoptile sections have been investigated. fc stimulates (86)rb(+) uptake within 1 min while auxin-enhanced uptake begins after a 15-20-min lag period. auxin has little or no effect on (86)rb(+) uptake at external phs of 6.0 or less, but substantial auxin effects can be observed in the range of ph 6.5 to 7.5. competition studies indicate that the uptake mechanism ...	1978	24414103
spectrophotometric phytochrome measurements in light-grown avena sativa l.	phytochrome was studied spectrophotometrically in avena sativa l. seedlings that had been grown for 6 d in continous white fluorescent light from lamps. greening was prevented through the use of the herbicide san 9789. when placed in the light, phytochrome (ptot) decreased with first order kinetics (τ1/2 ≈ 2 h) but reached a stable low level (≈2.5% of the dark level) after 36 h. this concentration of phytochrome remained constant in the light and during the initial hours of a subsequent dark per ...	1978	24408470
the contribution of tonoplast and plasma membrane to the electrical properties of a higher-plant cell.	the cytoplasm of subepidermal parenchyma cells of avena sativa l. coleoptiles was collected at one end of the cell by centrifugation. the electrical properties of both plasmalemma and tonoplast were then examined with microelectrodes inserted into both cytoplasm and vacuole of the same cell. the input resistance of the cytoplasm measured with either electrode was 7.5±0.8 mω while that of the vacuole measured with the single vacuolar electrode and a bridge circuit was 29.2±3.1 mω. the latter valu ...	1978	24408463
control of mitochondrial activities by phytochrome during greening.	mitochondria isolated from 7-day old darkgrown avena sativa l. (var. arnold) laminae given 5 min illumination of red light, followed by varying lengths of darkness up to 3 h, showed at least a twofold increase in the rates of both nadh-dependent oxygen consumption and respiratory chain phosphorylation over those of mitochondria isolated from unilluminated tissue. similar organelles, isolated from tissue given either far-red or red followed by far-red pretreatment, exhibited rates of both functio ...	1979	24311037
nonhormonal induction of h efflux from plant tissues and its correlation with growth.	when the esterase substrate alpha-naphthyl acetate is added to segments from coleoptiles of oat (avena sativa l., var. victory) or corn (zea mays l., bear hybrid wf 9 x 38) or to roots of lentil (lens culinaris med.), it is rapidly taken up and hydrolyzed to alpha-naphthol and acetic acid. this technique was used to generate intracellular acid and to study the effect of its efflux on growth. with corn coleoptile segments, treatment with alpha-naphthyl acetate induced more rapid and more prolonge ...	1979	16592739
cyanide inhibition of acid-induced growth in avena coleoptile segments.	the comparative effects of metabolic inhibitors on acid- and auxininduced growth in oat (avena sativa l. var. victory) coleoptile segments have been examined. acid (ph 4)-induced growth in both peeled and unpeeled segments is inhibited by 1 millimolar kcn when added at the time of acidification. kcn inhibits total acid-induced growth by 59 and 76%, respectively, in peeled and nonpeeled segments during the first 60 minutes. the growth rate of cyanide-treated tissue drops to zero or near zero in b ...	1979	16661034
phytochrome immunoaffinity purification.	we have developed a phytochrome immunoaffinity purification procedure that yields undegraded oat (avena sativa l., cv. garry) phytochrome of greater than 98% purity within 2 hours when starting with a brushite-purified preparation. immunoaffinity-purified phytochrome, except for its greater purity, is indistinguishable from conventionally purified phytochrome by gel exclusion chromatography, isoelectric focusing, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. we have also used th ...	1979	16660959
short term phytochrome control of oat coleoptile and pea epicotyl growth.	continuous recordings of the effect of light on oat (avena sativa l. cv. victory) coleoptile and pea (pisum sativum l. cv. alaska) epicotyl growth were made. using a single excised coleoptile 10 minutes of red light was found to promote growth after a latent period of 46 minutes. the stimulation was transient and was not far red-reversible. blue and far red light also promoted growth with similar kinetics. the action of continuous red or far red light was similar to that of 10-minute light. the ...	1979	16660744
kinetics of mitochondrial phosphate transport and rates of respiration and phosphorylation during greening of etiolated avena leaves.	using the technique of silicone oil filtration of organelles and the inhibitor stop method, the kinetics of transport of inorganic phosphate across the inner mitochondrial membrane were tested in relation to different stages of greening (0 to 24 h) of etiolated laminae of avena sativa l., and compared to the rates of oxygen consumption and atp formation. the results demonstrate that there is a pronounced increase in phosphate transport after 3 h of greening, reaching values for vmax (about 17 μm ...	1979	24407321
protein synthesis and auxin-induced growth: inhibitor studies.	we have compared the effects of cycloheximide (chi) and two other rapid and effective inhibitors of protein synthesis, pactamycin and 2-(4-methyl-2,6-dinitroanilino)-n-methyl proprionamide (mdmp), on protein synthesis, respiration, auxin-induced growth and h(+)-excreation of avena sativa l. coleoptiles. all three compounds inhibit protein synthesis without affecting respiration. the effectiveness of the inhibitors against h(+)-excretion and growth correlates with their ability to inhibit protein ...	1979	24317859
studies on lysine analogs, aspartate-derived amino acids, and attempted mutant selection on oat seedlings.	the lysine analogs s-2-aminoethyl-l-cysteine (aec) and dl-δ-hydroxylysine (dhl) caused severe growth inhibition in dark-grown oat seedlings (avena sativa l. and a. nuda l.) at similar concentrations while l-lysine methyl ester (lme) had little effect. lysine, arginine, and ornithine reversed the inhibition caused by aec and dhl, the order of effectiveness being lysine>arginine>ornithine. of aspartate-pathway amino acids, tested individually and in combinations for inhibitory effects on seedling ...	1979	24317756
effects of osmotic stress on polar auxin transport in avena mesocotyl sections.	segments of mesocotyls of avena sativa l. transported [1-(14)c]indol-3yl-acetic acid (iaa) with strictly basipetal polarity. treatment of the segments with solutions of sorbitol caused a striking increase in basipetal auxin transport, which was greatest at concentrations around 0.5 m. similar effects were observed with mannitol or quebrachitol as osmotica, but with glucose or sucrose the increases were smaller. polar transport was still detectable in segments treated with 1.2 m sorbitol. the eff ...	1979	24317665
comparison of reductions in adenosine triphosphate content, plasma membrane-associated adenosine triphosphatase activity, and potassium absorption in oat roots by diethylstilbestrol.	the possibility was investigated that diethylstilbestrol (des) inhibits potassium absorption in oat (avena sativa l. cv. goodfield) roots by inhibiting mitochondrial functions in addition to inhibiting the plasma membrane atpase. des at 10(-6) molar stimulated the mitochondrial atpase slightly, but higher concentrations had no effect. oxidative phosphorylation by isolated mitochondria was inhibited 50% by 2.6 x 10(-5) molar des; concentrations of 10(-4) molar or greater were completely inhibitor ...	1979	16660692
inhibition of adenosine triphosphatase activity of the plasma membrane fraction of oat roots by diethylstilbestrol.	diethylstibestrol (des) inhibited noncompetitively the atpase in the plasma membrane fraction from avena sativa l. cv. goodfield roots when assayed in the presence of mgso(4) or mgso(4) plus kcl. in the presence of mgso(4), 7.1x10(-5) molar des inhibited the enzyme 50%; whereas in the presence of mgso(4) and kcl, 1.3x10(-4) molar des was required for the same inhibition. dixon plots indicated that in the presence of mgso(4), one molecule of des bound to one molecule of atpase; however, in the pr ...	1979	16660690
effect of diethylstilbestrol on ion fluxes in oat roots.	effects of diethylstilbestrol (des) on ion fluxes in oat roots (avena sativa l.) were investigated by measuring k(+) and cl(-) absorption and k(+) efflux. des rapidly decreased the absorption of k(+) ((86)rb) and (36)cl(-) by excised roots; 10(-4) molar des inhibited cl(-) absorption in 1 minute and k(+) absorption in 1 to 2 minutes. with a 10-minute incubation period, k(+) and cl(-) absorption were inhibited 50% by 1.1x10(-5) molar and 8.4x10(-6) molar des, respectively. treatment for 3 minutes ...	1979	16660689
red light and auxin effects on rubidium uptake by oat coleoptile and pea epicotyl segments.	apical segments of etiolated oat (avena sativa l. cv. victory) coleoptiles showed enhanced uptake of [(86)rb(+)] when tested 30 minutes after a 5-minute red irradiation. the response was partly reversible by far red light. uptake was sensitive to carbonyl cyanide m-chlorophenyl hydrazone, but not to isotonic mannitol. indoleacetic acid (10(-7) molar) caused a very pronounced and rapid stimulation of uptake. basal coleoptile segments also exhibited a red light-enhanced uptake, but not an effect o ...	1979	16660665
possible role of volatile fatty acids and abscisic acid in the dormancy of oats.	species of avena differ markedly in their levels of pre- and post-harvest dormancy. these species offer the opportunity of determining if dormancy is related to the endogenous level of growth inhibitor. germinability in two species of differing levels of dormancy, common oat avena sativa l., and wild oat avena fatua l. was assessed as were the contents of abscisic acid and volatile fatty acids of chain length c(6)-c(10). in a. sativa which did not possess postharvest dormancy there was no correl ...	1979	16660807
glycerolipid synthesis in avena leaves during greening of etiolated seedlings ii. α-linolenic acid synthesis.	to determine the synthesis of α-linolenic acid esterified to galactolipids, etiolated leaves from avena sativa l. were fed with [1-(14)c]acetate for the first 3 hr of greening, and the redistribution of (14)c incorporated into the fatty acid moieties of lipid classes was examined during a 21-hr chase. phosphatidylcholine (pc) was most heavily labeled, but lost a large portion of its (14)c during the chase. galactolipids, such as monogalactosyl-diglyceride (mgdg) and digalactosyldiglyceride (dgdg ...	1980	25385976
glycerolipid synthesis in avena leaves during greening of etiolated seedlings i. lipid changes in leaves.	etiolated seedlings of avena sativa l. were illuminated under fluorescent light of 1,500 lux at 25°c and the lipid changes in their first leaves and isolated plastids were followed during 24 hr of greening. lipid changes were divided into a degradation phase [0 hr of illumination (hr-l) to 3 hr-l] and a synthetic phase (3 hr-l to 24 hr-l). in the degradation phase, which paralleled prolamellar body transformation in the plastids, both plastidic lipids, monogalactosyldiglyceride (mgdg), digalacto ...	1980	25385975
effects of peeling on the surface structure of the avena coleoptile: implications for hormone research.	coleoptiles of oats (avena sativa l.) are often peeled in order to observe hormone-enhanced acidification of the external medium. it is shown by means of the scanning electron microscope that peeling largely removes a single layer of cells, the epidermis with its cuticle. strips of intact and damaged epidermal cells remain, but most of the newly exposed surface is composed of cortical cells. the cortical face is relatively intact, except that some cells appear punctured and some are broken when ...	1980	24306888
rapid separation of the plastid, mitochondrial, and cytoplasmic fractions from intact leaf protoplasts of avena : determination of in vivo atp pool sizes during greening.	purified intact protoplasts were isolated from etiolated and greening leaves of avena sativa. they were ruptured by forcing them through a 20-μm aperture nylon net and immediately thereafter fractionated into a pure pellet of plastids (well above 70% of total plastids), a layer of mitochondria only slightly contaminated by other cellular constituents (about 50% of total mitochondria), and a cytoplasmic supernatant. this was achieved within 60 s by an integrated method of homogenation of protopla ...	1980	24306801
hormonal regulation of lateral bud (tiller) release in oats (avena sativa l.).	stem segments containing a single node and quiescent lateral bud (tiller) were excised from the bases of oat shoots (cv. ;victory') and used to study the effects of plant hormones on release of lateral buds and development of adventitious root primordia. kinetin (10(-5) and 10(-6) molar) stimulates development of tillers and inhibits development of root primordia, whereas indoleacetic acid (iaa) (10(-5) and 10(-6) molar) causes the reverse effects. abscisic acid strongly inhibits kinetin-induced ...	1980	16661589
phytochrome pelletability induced by irradiation in vivo: mixing experiments.	samples of irradiated and control avena sativa shoot tissue were homogenized together to determine whether, during homogenization phytochrome from irradiated tissue can bind to the particulate material simultaneously extracted from the control tissue. the level of phytochrome pelletability for such mixed tissue homogenizations is equal to: (a) the values obtained when the extracts from separate homogenizations of the two batches of tissue are mixed and then centrifuged; and (b) the arithmetic me ...	1980	16661550
protein patterns in the oat coleoptile as influenced by auxin and by protein turnover.	synthesis of growth-limiting proteins (glp) is required for continued auxin-induced elongation of oat (avena sativa l.) coleoptiles. in order to determine whether glp synthesis is dependent or independent of auxin, a double-labeling ratio technique, coupled with disc-gel electrophoresis, has been used to assess the effect of auxin on the pattern of protein synthesis. sections were peeled to enhance amino-acid uptake; proteins were labeled with [(14)c]- or [(3)h] leucine in the presence or absenc ...	1980	24310183
influence of anaerobiosis on chlorophyll biosynthesis in greening oat seedlings (avena sativa l.).	the influence of anaerobiosis for 0.5 to 15 hours on the last steps of chlorophyll biosynthesis of etiolated oat seedlings was investigated. phototransformation of protochlorophyllide to chlorophyllide is only slightly reduced and esterification of chlorophyllide is slightly increased by pretreatment under anaerobic conditions. pretreated plants accumulate the geranylgeraniol ester of chlorophyllide rather than the phytol ester. enzymic hydrogenation of the esterifying alcohol geranylgeraniol to ...	1980	16661480
analysis of genetic changes in radiated and non-radiated bulk oat (avena sativa l.) populations.	in both radiated and non-radiated oat populations inbreeding coefficients increased more slowly than was expected on the assumption of full selfing and equal selective values for homozygotes and heterozygotes. assuming 1% outcrossing for oats and a selective value of 1.0 for the mean, the heterozygotes for two loci governing crown rust reaction have an advantage of 50% over the homozygotes. this study supports previous observations that the heterozygote often has a decided advantage in predomina ...	1980	24305854
isolation and identification of a senescence-promoting substance from wormwood (artemisia absinthium l.).	the senescence-promoting substance of wormwood (artemisia absinthium l.) as detected by the oat (avena sativa l. cv "victory") leaf assay has been identified as (-)-methyl jasmonate, methyl (1s, 2r)-3-oxo-2-(2'-cis-pentenyl)-cyclopentane-1-acetate, by gas-liquid chromatography-mass spectrometry and optical rotatory dispersion. its senescence-promoting effect was much stronger than that of abscisic acid, and even at such a low concentration as 1 to 2.5 micrograms per milliliter, it could complete ...	1980	16661414
detection and partial characterization of activity of chlorophyll synthetase in etioplast membranes.	the esterification of chlorophyllide a was investigated an irradiated etioplast-membrane fractions ('broken etioplasts') from oat seedlings (avena sativa l.). as a substrate, [1(-3)h]geranylgeraniol and its monophosphate and diphosphate derivatives were prepared by chemical synthesis. geranylgeraniol and its monphosphate derivative are incorporated into chlorophyll only in the presence of atp whereas the diphosphate derivative is incorporated also without atp. the yield of esterified chlorophyll ...	1980	7408876
the effect of light on the production of ethylene from 1-aminocyclopropane-1-carboxylic acid by leaves.	white light inhibits the conversion of 1-amino-cyclopropane-1-carboxylic acid (acc) in discs of green leaves of tobacco (nicotiana tabacum l.) and segments of oat (avena sativa l.) leaves by from 60 to 90%. etiolated oat leaves do not show this effect. the general nature of the effect is shown by its presence in both a mono- and a dicotyledon. since the leaves have been grown and pre-incubated in light, yet can produce from 2 to 9 times as much ethylene in the dark as in the light, it follows th ...	1980	24306252
metabolism of oat leaves during senescence: vi. changes in atp levels.	the atp content of 7-day-old avena sativa leaves during senescence in dark and in light, and after treatment with cytokinins and other reagents, has been determined by the luciferin-luciferase method. special care was taken to avoid decomposition of the atp, and a detailed procedure is presented for atp analysis at the picomole level. preliminary experiments with several inhibitors of photophosphorylation suggest, though not conclusively, that the delaying effect of light on senescence is mediat ...	1980	16661296
on the use of avena protoplasts to study chloroplast development.	different methods were tested to isolate protoplasts from etiolated, partially greened, and light-grown leaves of avena sativa. preparations with high yields and high photosynthetic capacities (time of illumination ≧4 h) were obtained when small transverse leaf segments were incubated for 2 h at 30°c in 2% cellulysin (calbiochem), 0.6 m mannitol, and 0.5% bovine serum albumin (bsa) at ph 5.6, without shaking. as measured by light-dependent o2 evolution or fixation of labeled bicarbonate, protopl ...	1980	24311173
electrical field effects induced in membranes of developing chloroplasts.	etioplasts, etiochloroplasts, and chloroplasts of avena sativa l. purified on a percoll gradient were subjected to increasing electric field strengths in the orifice of a hydrodynamically focussing coulter counter. the change in resistance of the orifice when an organelle is present correlates well with the size of the plastid for field strengths up to about 3.5 kv cm(-1). beyond this field strength, depending on the size of the organelle, the size is underestimated. the underestimation of the s ...	1980	24311160
partial characterization of undegraded oat phytochrome.	we characterized immunoaffinity-purified, undegraded oat (avena sativa l., cv. garry) phytochrome by several physicochemical techniques. phytochrome, of greater than 98% purity [hunt, r. e., & pratt, l. h. (1979) plant physiol. 64, 332-336], existed in solution as a dimer of its 118 000-dalton monomers and had a full complement of the typical amino acids with about 35% nonpolar residues, 115 carboxylic acid groups per monomer, and an average of one phosphate per monomer. although the dimer was n ...	1980	7352993