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1.
Two fractionation procedures were used to study the phenomenonof phytochrome pelletability or binding to a particulate fractionof maize coleoptiles. Using a revised procedure, we were unableto show an increase of phytochrome pelletability during darkincubation of red irradiated plant tissue, reported by Manabeand Furuya for pea seedlings (6), and the Pfr-enhanced affinityfor Pr in R/FR irradiated tissue as reported by Quail et al.(11). However, we were able to match these reported observationsusing a procedure which we have regarded as standard. In thestandard procedure, the irradiated tissue is homogenized andthe brei permitted to incubate in the dark at 0?C before fractionationby differential centrifugation prior to measurements of phytochromepelletability. In the revised procedure this incubation is eliminatedand fractionation and measurement follow directly on tissuehomogenization. A progressive decrease of particulate phytochromewas observed during dark incubation at 0?C of the brei fromred irradiated tissue, but no substantial decrease was observedduring dark incubation of the red irradiated tissue at 0?C.The decrease was not dependent on in vitro PfrPr reversion.In the case of R/FR irradiated tissues, phytochrome pelletabilitywas found to decrease during dark incubation of both the irradiatedtissue and its brei at 0?C. With these results and a recognitionof the tendency of phytochrome to dissociate from the particulatefraction in vitro, we have thus rationalized the results ofQuail et al. (11) and Manabe and Furuya (6). (Received August 12, 1976; )  相似文献   

2.
DAVIDSON  DOUGLAS 《Annals of botany》1958,22(2):183-195
Roots of Vicia faba were given combined X-ray and colchicinetreatments. Breaks were not visible immediately after irradiation,even at metaphase. Breaks and reunions were, therefore, scoredlater in 2x nuclei, and in the 4x nuclei derived from 2x nucleiafter colchicine treatment. It was shown that metaphase is themost sensitive stage of mitosis Breaks per chromosome are less frequent in 4x nuclei than in2x nuclei after irradiation of resting stage. This apparentphysiological difference between the two types of nuclei mayaffect either the frequency of breakage or of restitution. Afterthe irradiation of prophase, metaphase, or telophase cells,however, breaks per chromosome are more frequent in the 4x nucleithan they are in 2x nuclei in the same sample owing to the factthat the 2x, unlike the 4x nuclei, are not accurately timed.They must include cells irradiated during the less sensitiveresting stage. Chromosome reunion occurred, probably at telophase. Chromatidreunion and sister reunion did not occur frequently. Chromatidbreaks, like chromatid reunions, were infrequent except afterirradiation of resting stage cells. The evidence indicates thatthe chromosome, at metaphase just as at resting stage, reactsto X-rays as a single functional unit.  相似文献   

3.
HUME  D. E. 《Annals of botany》1991,67(6):533-541
Effects of cutting to 3 or 6 cm stubble height at frequenciesof 1, 2 or 4 weeks were investigated in young, vegetative, spacedplants of prairie grass (Bromus willdenowii Kunth), a tetraploidWesterwolds ryegrass (Lolium multiflorum Lam.) and perennialryegrass (Lolium perenne L.). Plants were grown for 8 weekson nutrient solution in a growth cabinet at day/night temperaturesof 15/10°C and in a short photoperiod. Leaf appearance,site filling and tiller numbers were all reduced by both increasedcutting frequency and a lower cutting height. The extent ofthese reductions was least in prairie grass and greatest inWesterwolds ryegrass. Relative growth rates in all species respondedin a similar manner with more frequent cutting and a lower cuttingheight. Cutting frequency had the greatest effect on growthrates, although the effect of cutting height increased withtime. Results confirm general recommendations of long intervalsbetween defoliations to achieve high yields for vegetative prairiegrass, but the relative amounts of dry matter harvested underthe different cutting regimes may be no different to that obtainedin ryegrass. Stubble height was of lesser importance in determiningyields. A typical U-shaped curve for depletion and recovery in water-solublecarbohydrates occurred after defoliation in all species, butlevels remained low at frequent cutting. Water-soluble carbohydratelevels in stubble and roots were higher in prairie grass. Regrowthat the end of the experiment was highly correlated with totalstubble and root weights (r = 0.84), while regrowth per tillershowed a good correlation with water-soluble carbohydrate content,although the response varied between species. Prairie grass, Bromus willdenowii Kunth, perennial ryegrass, Lolium perenne L., Westerwolds ryegrass, Lolium multiflorum Lam., cutting frequency, cutting height, leaf appearance, tillering, site filling, yield, regrowth, nitrogen, water-soluble carbohydrates  相似文献   

4.
HUME  D.E. 《Annals of botany》1991,68(1):1-11
Effects of time of initial cut and subsequent cutting interval(1, 2 or 4 weeks) were examined in a glasshouse during summer1988 for reproductive plants of three prairie grass cultivars(Bromus willdenowii Kunth), Westerwolds ryegrass (Lolium multiflorumLam.) and perennial ryegrass (Lolium perenne L.). Measurementswere made of tiller and leaf numbers, sites of tillering, reproductivedevelopment, and herbage quality and yields. Effect of timeof initial cutting on regrowth appeared to be independent ofstage of reproductive development and unrelated to any of themeasured plant parameters. Characteristics for each cultivaras identified during undisturbed growth prior to the initialcuts, were modified by the subsequent cutting frequencies. Perennial ryegrass had the highest yields under frequent cuttingwith high herbage quality. Westenwolds ryegrass and the prairiegrass cultivars ‘Grasslands Matua’ and ‘Primabel’had the highest yields with infrequent cutting, but lower herbagequality than in perennial ryegrass. At each cut, tiller deathin prairie grass was determined by the number of reproductivetillers, and in the ryegrasses also by the numbers of elongatedvegetative tillers. Recovery of tiller numbers was rapid andprimarily from inhibited tiller buds at the base of reproductivetillers. In prairie grass, tiller numbers were relatively unaffectedby cutting frequency, but at frequent cutting, many axillarytillers originated from vegetative tillers rather than frominhibited tiller buds at the base of reproductive tillers. Prairie grass, Bromus willdenowii Kunth, Westerwolds ryegrass, Lolium multiflorum Lam., perennial ryegrass, Lolium perenne L., first (initial) cut, cutting frequency, regrowth, leaf appearance, tillering, yield, nitrogen, water-soluble carbohydrates, herbage quality  相似文献   

5.
Epicuticular waxes were removed from the leaf surfaces of Oleaeuropaea and Prunus persica by washing with chloroform and theresulting rinses were analysed by high performance liquid chromatography(HPLC) for the presence of fluorescing compounds. Removal ofepicuticular waxes from leaves of some representative plantsby the same treatment resulted in a significant reduction inthe intensity of the blue fluorescence emitted from guard cells(Karabourniotis et al., 2001: Annals of Botany. doi:10.1006/anbo.2001.1386).Ferulic acid and p-coumaric acid, as well as a number of unidentifiedcompounds, were constituents of the rinses of both plants examinedbut only after alkaline hydrolysis of the samples. This indicatesthat both phenolic acids are tightly bound to the epicuticularwaxes of the leaves of these plants. HPLC chromatograms of rinsesderived either from the abaxial or adaxial surfaces of the hypostomaticleaves of O. europaea did not show significant qualitative differences.Nevertheless, ferulic acid (the main blue fluorescent component)was much more abundant in the abaxial than the adaxial surface.In P. persica, the composition of the sample derived from theabaxial surface was far more complex, and all constituents werepresent in much higher concentrations than in the sample derivedfrom the adaxial surface. Given the particular fluorescencecharacteristics of ferulic acid, the differences in its concentrationbetween abaxial and adaxial surfaces, and between the two species,and the fluorescence images of these surfaces under the microscope,we propose that this compound is probably the main epicuticularconstituent responsible for the blue fluorescence emitted byguard cells of the species examined. The functional significanceof the findings is discussed. Copyright 2001 Annals of BotanyCompany Cuticle, epicuticular waxes, ferulic acid, HPLC analysis, Olea europaea L., p-coumaric acid, phenolics,Prunus persica L., stomata  相似文献   

6.
Pools of ATP, ADP and AMP in algae were compared after extractionwith Trisbuffer, ethanol, chloroform, sulfuric acid, trichloroaceticacid and perchloric acid. Experimental organisms were Anacystisnidulans, Euglena gracilis, Chlorella kessleri and Scenedesmusobtusiusculus. Adenine nucleotides were determined by fireflyluciferase assay. Extraction of illuminated algae in situ with the different methodsresulted in great variations in the proportions between ATP,ADP and AMP. The sum of adenine nucleotides varied less. Extractionwith trichloroacetic acid or perchloric acid generally yieldedthe highest energy charge and ATP/ADP ratio. Experiments withilluminated Anacystis and Scenedesmus showed that extractionwith perchloric acid in situ gave higher yields of ATP in theextracts than if samples were withdrawn for extraction (timefor sample withdrawal {small tilde}1 sec). For Anacystis, itwas demonstrated that the extraction methods giving the highestproportions of ATP were suitable for studies on fluctuationsof the adenine nucleotide pools at transitions from dark tolight. 1 Permanent address: National Defence Research Institute, Department4, S-172 04 Sundbyberg, Sweden. (Received September 4, 1978; )  相似文献   

7.
A new indole-3-acetic acid (IAA) metabolite in the root of Viciafaba L. cv. Chukyo was identified as 3-hydroxy-2-indolone-3-acetylasparticacid, with the simpler name of dioxindole-3-acetylaspartic acid,by comparison with the authentic sample. Formation of dioxindole-3-aceticacid conjugates seems to be a major route of IAA metabolismin Vicia roots. (Received October 22, 1985; Accepted January 7, 1986)  相似文献   

8.
Perceptual Properties of Benzoic Acid Derivatives   总被引:1,自引:1,他引:0  
Peleg  H.; Noble  A.C. 《Chemical senses》1995,20(4):393-400
Sensory properties of equimolar concentrations of benzoic acidderivatives were examined using time-intensity procedures. Significantdifferences in maximum intensities (P < 0.005) were foundfor astringency, bitterness, prickling, sourness and sweetness.Although these compounds differed only in the number and positionof the hydroxy groups, they exhibited quite different profiles.Gentisic acid had the highest sourness and bitterness maximumintensity, salicylic and gentisic acids were highest in astringency,and m-hydroxybenzoic acid was the sweetest sample. Benzoic acidhad the highest intensity of prickling feeling which lasted20 s longer than salicylic acid and 40 s longer than the othersamples which elicited lowest intensity of prickling sensation.Chem. Senses 20: 393–400, 1995.  相似文献   

9.
Culvenor  R. A. 《Annals of botany》1993,72(6):559-568
Two cultivars of phalaris (Phalaris aquatica L.), Australianand Sirolan, were cut at four stages of development in a controlledenvironment to study factors involved in the sensitivity ofphalaris to grazing during spring. Effects on tillering, regrowthafter cutting and regenerative capacity after an artificiallyimposed summer dormant period were observed. Compared with Australian,Sirolan cut after the commencement of stem elongation was characterizedby a higher degree of decapitation due to more synchronous elevationof its apices, and displayed a more severe reduction in regrowth,size of tiller bases and dormant buds and levels of carbohydratereserves in summer relative to plants cut before stem elongation.Suppressed bud activity in tillers of Sirolan decapitated atearly stem elongation, and the potential for profuse tilleringassociated with low bud dormancy after cutting at the earlyboot stage, could reduce persistence under field conditions. Relative to plants cut before stem elongation, regenerationgrowth after 'summer' by plants cut during reproductive developmentwas depressed more severely for Sirolan (56-70%; P 0·05)than Australian (28%; n.s), a result more closely related toregenerating tiller size than number. Regeneration growth didnot differ significantly with stage reproductive developmentat cutting in either cultivar. Regenerative capacity of phalariscut during reproductive development can be considered to dependon an increasing contribution from buds on bases of tillersdecapitated when cut and a contribution from buds on intacttiller bases which declines as the stage of cutting becomeslater. The balance between these source will depend on the environment.Copyright1993, 1999 Academic Press Phalaris aquatica L., phalaris, regrowth, persistence, defoliation, cutting, perennial grass, tillering  相似文献   

10.
DE RUITER  H. A. 《Annals of botany》1996,77(1):99-104
In three experiments (twoin-vivo, onein-vitro), an attempt wasmade to separate the possible effects of age and position ofaxillary buds of chrysanthemum on bud outgrowth and the subsequentquality of cuttings. In thein-vivoexperiments, bud age and bud position were notsignificant factors in bud outgrowth and subsequent qualityof cuttings. Nevertheless, most outgrowth parameters showedslightly higher values for the lower positioned buds and thetime needed to produce a cutting tended to decrease with theage of the axillary bud. In thein-vitroexperiment, the relationship between age and thevarious parameters showed an optimum. axillary bud; Chrysanthemum morifolium; Dendranthema grandiflora; Age; cutting; chrysanthemum; position  相似文献   

11.
The photosynthetic production of oxalic acid in Oxalis corniculata   总被引:2,自引:0,他引:2  
The biogenesis of oxalic acid in Oxalis corniculata has beeninvestigated. In O. corniculata the bulk of the oxalic acidis produced by CO2 fixation both in light and in darkness butthe rate of its photosynthetic formation is much higher thanin darkness. Several other plants some of which are known toaccumulate oxalic acid e.g., Biophytum sensitivum, Averrhoacarambola, Impatiens balsamina, Amorphophallus campanulatusand Colocassia antiquorum also fix 14CO2 into oxalic acid photosyntheticallywithin 1 min of exposure to the gas. In O. corniculata 14C canbe detected in oxalic acid within 5 sec and about half of thetotal 14C fixed in the 70% ethanol soluble fraction can be locatedin this compound after 5 min. This is accompanied by a declineof radioactivity in two compounds, the chromatographic behaviourand melting points of one of which and its DNP hydrazone aresimilar to those of an authentic sample of glyoxylic acid. Whenglyoxylate 1, 2-14C is incubated with Oxalis leaf homogenateit is converted to oxalate-14C. Glycolate is also metabolizedto oxalate. The conversion of both glycolate and glyoxylateare favoured by light. The C2 compounds acetate and glycinehowever are utilized rather poorly. Sucrose-14C is also notmetabolized markedly for this purpose. (Received August 20, 1969; )  相似文献   

12.
The amphidiploid (AACC) nuclear genome of Brassica napus (oil-seedrape) contains c. 5 ? 105 copies of a simple, highly repetitiveDNA element; each repeat is 176 or 177 base pairs long and isdefined by Hind III cutting sites. The diploid (AA) Brassicacampestris (turnip) possesses a very similar repetitive DNA,the consensus sequence of which does not differ from that inB. napus. The 176/177 bp unit consists of three 59 bp sub-units,defined by vestigial EcoRII sites. Analysis of the distributionof variants from consensus in adjacent and non-adjacent unitsprovides evidence for homogenization of sequences by the fixationof independent mutations and for tandem duplication of units.Within units, there is also evidence for inversion and tandemduplication of short (5–8 bp) motifs. Previously published data show that 176/177 base pair repetitiveDNA elements, defined by Hind III cutting sites, are also presentin Sinapis and Raphanus. There is a sequence homology betweenBrassica and Sinapis, and between Brassica and Raphanus, of75%. Sequence homology between Raphanus and Sinapis is 73%. Key words: Repetitive DNA, Brassica, Cruciferae  相似文献   

13.
When seedlings of Cuscuta japonica were grown with Vigna radiata(the host plant) in a flower pot for 6 d under white light andthen irradiated with far-red or blue light (ca. 6 µmolphotons m–2 s–1), the seedlings parasitized V. radiata.However, no parasitism of the seedlings was observed under redor white light or in darkness. The parasitic behavior of seedlingsof C. japonica was observed even if an acrylic rod was usedas a substitute for the host plant. Upon incubation under far-redlight, the seedling twined tightly around the rod and developedhaustoria towards it. Haustoria also developed when apical andsubapical regions of seedlings were held between two glass platesthat were about 0.7 mm apart and were irradiated with far-redlight. However, no haustoria were induced by either the holdor irradiation alone. These results indicate that parasitismof Cuscuta japonica is controlled by the cooperative effectsof two physical signals, far-red light and appropriate tactilepressure. Our findings suggest that parasitism by the genusCuscuta involves a novel strategy. (Received April 10, 1996; Accepted August 21, 1996)  相似文献   

14.
ASCASO  C.; RAPSCH  S. 《Annals of botany》1986,57(3):407-413
The amount of total chlorophyll, chlorophylls a and b as wellas the ratio of a to b decreased in chloroplasts isolated fromQuercus rotundifolia leaves, kept for 17 d in a solution of35.5 µM evernic acid in 1 mM Na HCO3, when compared withthe chloroplasts of control leaves (kept in NaHCO3). The chloroplastsin the spongy parenchyma were smaller and the amount of starchand plastoglobuli lower. The number of grana per chloroplastsection, the number of thylakoids per grana and the height ofgrana stacks were also less in the chloroplasts of leaves treatedwith evernic acid. Quantitative ultrastructural differenceswere determined by means of electron microscopy and image analysistechniques. Quercus rotundifolia Lam., chloroplasts, ultrastructure, lichens, evernic acid  相似文献   

15.
One-node potato (Solanum tuberosum L. cv. ‘Katahdin’)cuttings were used to study early anatomical changes associatedwith tuberization. Starch deposition and the percentage frequencyof cells in mitosis increased in the medullary region of thebud within 1 d after cutting, whereas increases in average cellsize were not detected until 4 d after cutting. Starch depositionand mitosis were the earliest detectable changes in anatomyassociated with tuber initiation. Potato, Solanum tuberosum L., tuber initiation, cuttings, cell enlargement, mitosis, starch deposition  相似文献   

16.
Changes in total nitrogen and free amino acid contents in stemcuttings of Morus alba have been studied. The fresh and dryweights and total nitrogen amounts of the parent stems of cuttingsdecreased initially after cutting. Their increase follows theformation of main roots in cuttings, suggesting that, like carbohydrates,sugars and starch, stored nitrogenous substances are used forsprouting and rooting of cuttings. Amino acids found in stems,roots and shoots are those common in other higher plants withthe exception of pipecolic acid and 5-hydroxypipecolic acid.Significant changes in the levels of asparagine, proline, arginine,-aminobutyric acid and alanine in roots, bark and wood of parentstems were observed during cutting growth, whereas those ofother amino acids remained comparatively constant; the mostpredominant amino acid in the starting materials was proline.while that in the cuttings during growth was asparagine. Theresults suggest that, among free amino acids, asparagine, prolineand arginine play the major part in storage of nitrogen in mulberry.The importance of glut-amine and asparagine in nitrogen metabolismin mulberry has been discussed.  相似文献   

17.
Gibberellic acid inhibited rooting but increased extension ofpea and bean stem cuttings. Indolylacetic acid usually had acontrary effect both on extension and on root initiation. Itwas found possible to separate the effects of gibberellic acidon extension and rooting. Small doses of gibberellic acid appliedto the bases of cuttings reduced rooting without increasingextension. Small apical doses increased extension without reducingrooting. Disbudding cuttings prevented extension, but gibberellicacid inhibited rooting of disbudded cuttings as strongly asthat of normal cuttings. It has thus been found necessary todiscard an earlier hypothesis that inhibition of rooting bygibberellic acid was a consequence of a diversion of essentialmetabolites to the extending apical regions of the cutting.The antagonism between gibberellic acid and indolylacetic acidwas non-competitive. Gibberellin A1, known to occur naturallyin Phaseolus, was as active a rooting inhibitor as gibberellicacid. It is now believed that inhibition of rooting of cuttingsby gibberellins is a direct local effect, preventing those earlycell divisions involved in transformation of mature stem tissuesto a meristematic condition.  相似文献   

18.
Seeds irradiated with red light and then re-dried will respondto this light treatment on subsequent rehydration in the dark.If such high-Pfr seeds are irradiated in the dry state withfar-red light immediately before rehydration the percentagegermination is significantly reduced in the case of Plantagomajor and Sinapis arvensis but increased in Bromus steriliswhere Pfr inhibits germination. This effect of far-red lightcan be reversed by red light despite the fact that red lightalone has no effect on dry seed. This is due to the interconversionof Pfr and the red light absorbing phytochrome intermediatecomplex meta-Fa. If there is a delay between far-red irradiationand rehydration of Sinapis seeds, the inhibitory effect of thefar-red irradiation becomes progressively less the longer thedelay. This reduction in effectiveness of far-red is interpretedin terms of a dark reversal of meta-Fa to Pfr with a half-lifeof about 4–6 h. The reappearance of Pfr is either veryslow or docs not occur in dehydrated Plantago seeds, as far-redtight given 96 h prior to hydration is just as inhibitory asfar-red light given immediately before hydration. Meta-Fa doesappear to revert to Pfr in darkness in Bromus seeds, but onlyvery slowly. The rapid increase in effectiveness of red irradiationduring rehydration of high-Pfr Plantago seeds suggests that,in this species, the pre-treatment used in preparation of high-Pfrseeds may increase the receptivity or amount of the Pfr reactionpartner. Key words: Phytochrome intermediates, Seeds, Germination  相似文献   

19.
The interactive effects of gibberellic acid, abscisic acid,and benzyladenine were studied in relation to runner formationof the everbearing strawberry. In two of three cultivars studied,Ozark Beauty and Superfection, exogenous gibberellic acid stimulatedrunner formation and inhibited flowering. In the Geneva cultivar,a shy runner producer, gibberellic acid application as a foliarspray failed to induce runners. When applied in combinationwith benzyladenine, gibberellic acid greatly stimulated runnerformation Benzyladenine alone had no effect on runnering. Exogenous abscisic acid inhibited petiole length and runnerformation and had no influence on the number of inflorescencesinitiated. Response to exogenous gibberellic acid or abscisicacid varied according to the reproductive or vegetative stagethe plant exhibited at the time of treatment. Activity of endogenous gibberellin-like substances was not substantiallydifferent between flowering and non-flowering field-grown Genevaplants when sampled in long day lengths of August. Endogenousinhibitors were highly active in flowering Geneva plants andrelatively inactive in non-flowering plants The implications of these findings on hormonal balance in thestrawberry are discussed.  相似文献   

20.
5-Keto-D-[1-14C]gluconic acid, the most effective precursorof L(+)tartaric acid among all labeled compounds which haveever been tested in grapes, was found to be a good precursorof L(+)tartaric acid in a species of Pelargonium. The synthesisof labeled L(+)tartaric acid from D-[1-14C]glucose in Pelargoniumwas remarkably depressed when a 0.5% solution of D-gluconateor 5-keto-D-gluconate was administered continuously to leavestogether with D-[1-14C]glucose. Our results provide strong evidence that D-[1-14C]glucose ismetabolized in Pelargonium to give labeled L(+)tartaric acidvia (probably D-gluconic acid and) 5-keto-D-gluconic acid withoutpassing through L-ascorbic acid. Labeled L-idonic acid was found in young leaves of Pelargoniumwhich had been labeled with L-[U-14C]ascorbic acid. The synthesisof the labeled L-idonic acid increased when a 0.1% solutionof L-threonate was administered continuously to leaves togetherwith L-[U-14C]ascorbic acid. Specifically labeled compounds, recognized as the members ofthe synthetic pathway for L(+)tartaric acid from L-ascorbicacid via L-idonic acid in grapes, were administered to youngleaves of Pelargonium. Each compound (2-keto-L-[U-14C]idonicacid, L-[U-14C]idonic acid, 5-keto-D-[1-14C]gluconic acid and5-keto-D-[6-14C]gluconic acid) was partly metabolized, as ingrapes. The metabolic pathway starting from L-ascorbic acidto L(+)tartaric acid via L-idonic acid, however, did not actuallycontribute to the synthesis of L(+)tartaric acid in Pelargoniumprobably because the activity of each metabolic step was muchlower than that observed in grapes. (Received May 28, 1984; Accepted July 30, 1984)  相似文献   

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