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1.
Reciprocal transfers of Nicotiana tabacum cv. Xanthi nc. leafexplants were made daily between root inducing medium (RIM)and shoot inducing medium (SIM), SIM and a basal medium containingno growth regulators (BM), and RIM and BM. It was found thatthe explants became determined for shoot production after 6d, while roots were produced after only 1 d on RIM before transferto BM. The competence of the explant to produce roots was greatlyreduced by culture on BM prior to culture on RIM. There wasfar less reduction in shoot numbers with preculture on BM. Explantswere found to be only weakly canalized for both caulogenesisand rhizogenesis for the first 2 d after determination. Thereafterthey became strongly canalized. Transfers were also made fromBM to SIM and back to BM, which revealed that the explants becamecompetent for caulogenesis in the absence of cytokinins priorto determination. The period for which SIM is required can bereduced to only 1 d. Key words: Nicotiana tabacum, in vitro, organogenesis, competence, determination 相似文献
2.
The role of ethylene during in vitro maturation of Nicotianatabacum pollen from the mld-binucleate (MB) stage was analysedby the addition of aminooxyacetic acid (AOA), aminoethoxyvinylglycine(AVG), CoCl2 and AgNO3 to the maturation medium (AMGLu). Anincrease in ethylene production was obtained in both isolatedpollen and pollen surrounded by sporophytic tissue during insitu maturation. in vitro maturation of pollen was inhibitedby AOA and AVG; ACC and ethrel were able to overcome this inhibitoryeffect. Cyclohexylamine (CHA) reverted the inhibition provokedby both Ag+ and Co2+ The results reported in this paper indicatethat ethylene is one of the factors implicated in in vitro maturationof MB pollen of Nicotiana tabacum. Key words: Nicotiana tabacum, maturation, germination, pollen, ethylene 相似文献
3.
VAN DEN ENDE G.; BARENDSE G. W. M.; KEMP A.; CROES A. F. 《Journal of experimental botany》1984,35(12):1853-1859
The effect of glucose on flower bud formation was studied inthin-layer tissue cultures of epidermal strips from flower stalksof Nicotiana tabacum L. cv. Samsun. A minimum concentration of 30 mol m3 glucose in the MS-mediumcontaining 1.0 mmol m3 of both NAA and BA was necessaryfor flower bud formation. With 150 mol m3 glucose a minimumstay of 10 d was required for optimal flower bud formation. Withholding glucose for a limited period at different time intervalsafter the onset of culture caused a delay in flower bud formationand did not affect previous development on glucose. The resultsindicated that competence for flower bud initiation is not restrictedto the early stage of culture. The process may start at anytime later at the appropriate glucose concentration. However,for both optimal initiation and further development of flowerbuds the presence of a metabolizable sugar is required. Incubationof the tissue on glucose is associated with higher respirationrate. Key words: Flower formation, Glucose, mannitol, Nicotiana tabacum, Respiration, tissue culture 相似文献
4.
Video images of the distributional pattern of membrane-associatedcalcium (Ca2+) and calmodulin (CaM) have been documented andanalysed during pollen hydration, germination and tip growthin Nicotiana tabacum. Digitization of fluorescence microscopeimages of chlorotetracycline (CTC) and fluphenazine (FPZ)-fluorescenceemissions reveal that there is a maximum concentration of membrane-associatedCa2+ and also CaM in the vicinity of germination apertures ofhydrated pollen. With the onset of germination relatively higheramounts of Ca2+ and CaM were found to regionalize towards theaperture through which the pollen tube would emerge Both shortand long growing pollen tubes manifest tip-to-base Ca2+ andCaM gradients which are disturbed in non-growing tubes. Tubegrowth and the Ca2+-gradient were significantly affected byvanadate and verapamil suggesting that both a vanadate-sensitiveCa2+-transport system and verapamil-sensitive Ca2+ channelsare involved in maintaining Ca2+ homeostasis during pollen germinationand tube growth. The possible interactions of Ca2+ and CaM withdifferent cytoskeletal proteins modulating organelle movementare also briefly discussed. Image analysis, calcium, calmodulin, Nicotiana tabacum L., pollen germination, pollen tube, tip growth, Ca2+-channels, Ca2+ transport ATPase 相似文献
5.
Developmental Pattern of Root and Shoot Organogenesis in Cultured Leaf Explants of Nicotiana tabacum cv. Xanthi nc. 总被引:1,自引:0,他引:1
Caulogenesis and rhizogenesis were studied in cultured leafexplants of Nicotiana tabacum cv. Xanthi nc. using both lightand scanning electron microscopy. The timing of organ appearancewas also recorded. The patterns of development seen were comparedto each other and to that in explants grown on growth regulator-freemedium. Shoots first appeared after 12 d in culture and rootsafter 7 d. In caulogenesis nodules appear at the explant edgeand from these the shoots arise. The nodules are mainly derivedfrom palisade mesophyll cells, along with some spongy mesophylland bundle-sheath cells. The nodules form a continuous row alongthe edge of the explant and their initiation appears to be centredon veins. Shoots are produced indirectly. Roots are produceddirectly from bundle-sheath and vein parenchyma cells. Withoutplant growth regulators bundle-sheath cells still divide, althoughonly a few divisions were seen. Key words: Nicotiana tabacum, in vitro, caulogenesis, rhizogenesis 相似文献
6.
The response of pollen development to low or high temperatureregimes was studied to determine the conditions suitable forthe formation of fertile pollen in the mango cv. 'Kensington'.The phase most sensitive to the degree and duration of temperaturestress was that from meiosis to the pre-vacuolate microspore(about 3 d duration at 25/20 °C) though vacuolated microsporeswere also sensitive to low temperature. Night temperatures below10 °C resulted in pollen grains with a low viability (<50%). A temperature between 15 and 33 °C during the phasefrom meiosis to the pre-vacuolate microspore was optimum forpollen development (70-85% pollen viability). Analysis of field records showed a linear negative correlationbetween percentage of pollen viability and number of days whichhad a mean night temperature lower than 10 °C during theperiod from meiosis to early mature stage (y = 77·7-3·4x,r2 = 0·60). The temperature sensitive phase was estimatedto begin 155 degree days D = [(Tmax + Tmin)/2 - 10] before anthesisand to end 78 degree days before anthesis. This equation maybe useful as a means of predicting pollen viability in the fieldfrom temperature records and thus fruit set, date of maturityand yield. It may also aid in the selection of areas for growingmangoes in marginal climates.Copyright 1994, 1999 Academic Press Mangifera indica L. mango, microsporogenesis, pollen development, viability, sterility, temperature 相似文献
7.
Cetyltrimethylammonium bromide (CTAB), a cationic detergent,more effectively inhibited the activity of membrane-bound epidermaladenosine triphosphatase (ATPase) of tobacco (Nicotiana tabacumL. cv. Samsun) leaves than anionic or non-ionic detergents.The inhibition of ATPase activity was highly dependent on thelength of the alkyl chain of alkyltrimethylammonium: CTAB >dodecyltrimethylammonium bromide > n-octyltrimethylammoniumbromide trimethylammonium chloride cetyl bromide, comparedat 104 M. The last three derivatives hardly inhibitedthe activity. CTAB inhibition was equivalent to that due toother cationic detergents, cetylpyridinium bromide and cetylamine, but less than that by gramicidin S and tyrocidine andstronger than that by N,N'-dicyclohexylcarbodiimide and vanadate. These results show that a certain length of the alkyl chain(Cn>12) and the combination of both hydrophobic and chargedgroups of a detergent moiety are indispensable for inhibitingthe membrane-bound epidermal ATPase activity. (Received January 26, 1982; Accepted April 10, 1982) 相似文献
8.
Matoh Toru; Ishigaki Ken-ichi; Mizutani Masaharu; Matsunaga Waki; Takabe Keiji 《Plant & cell physiology》1992,33(8):1135-1141
Cultured cells of tobacco (Nicotiana tabacum L. cv. Bright Yellow2) grown under the standard culture conditions (1 mg boron liter1medium as boric acid) contained boron at a concentration of2.26 mg boron kg1 oven-dried cells and the protoplastcontained 1.26% of the boron in the cells. The cells requiredboron for growth and the half-maximum growth rate was obtainedwith 0.056 mg of boron liter1 medium. Subculturing thecells in media with lower concentrations of boron allowed selectionof cells that can grow even in the presence of 1 µg boronliter1 medium. Cell walls of the selected cells seemedto be thicker than those of the control cells and Golgi bodieswere accompanied by more secretory vesicles than those in thecontrol cells. (Received May 25, 1992; Accepted September 10, 1992) 相似文献
9.
Stem segments of non-tumorous Nicotiana glauca and N. langsdorffiiplants and of their tumor-producing amphidiploid F1 hybrid weretreated with 6-furfurylaminopurine (kinetin) prior to transporttests with applied labeled indoleacetic acid (IAA-2-14C). Kinetin-treatmentsincreased the uptake of IAA in non-tumorous shoots; the IAAuptake by N. langsdorffii segments was increased up to 3-fold.The auxin uptake in stem-segments of the tumor-forming hybrid,however, could not be increased significantly by kinetin. Theeven distribution of IAA-14C in segments of normal and tumorproneNicotiana shoots is stimulated by kinetin. Data are discussedin conjunction with previous results on auxin transport andtumorformation in Nicotiana. (Received August 8, 1972; ) 相似文献
10.
Visualization of Membrane Calcium and Calmodulin in Embryo Sacs in situ and Isolated from Petunia hybrida L. and Nicotiana tabacum L. 总被引:2,自引:0,他引:2
We have used chlorotetracycline (CTC) and fluphenazine (FPZ)as fluorescent probes to visualize the distributional patternsof membrane calcium (mCa2+) and the Ca2+-receptor protein calmodulin(CaM) in various cell types of unfixed living isolated and unisolatedembryo sacs of Petunia hydrida L. and Nicotiana tabacum L. Ourresults indicate that in the young embryo sacs of Petunia, bothsynergids and the central cell sequester relatively higher amountsof mCa2+ and CaM than the egg cell and the antipodals. Much of the mCa2+ in the synergids is polarized in its distributionin that the mCa2+ is higher towards the micropylar end of thesynergids. Interestingly, in the mature embryo sacs of Petuniaonly one of the two synergids and the egg cell proper manifesta higher level of mCa2+. In vivo only one of the synergids inthe young as well as in the mature embryo sacs if Nicotianaconsistently show higher mCa2+. In the mature embryo sacs of Petunia the level of CaM is almostuniform in all the cell types except that one of the synergidsand the three antipodal cells show a slightly higher level ofCaM. The possible implications of these findings in the late eventsof vectorial orientation of pollen tube tip, pollen-tube-synergidinteractions and sperm delivery mechanism are discussed.Copyright1993, 1999 Academic Press Membrane-Ca2+, calmodulin, living embryo sacs, Petunia, Nicotiana, pollen tube-synergid interaction 相似文献
11.
Growth and ion accumulation were measured in callus culturesof Cicer arietinum L. cv. BG-203, grown on media supplementedwith 0200 mol m3 NaCl. Fresh and dry weights decreasedat concentrations ranging from 100200 mol m3,the reduction being greater during the third and fourth weeksof culture. Slight stimulation of growth was observed at 25and 50 mol m3 NaCl. There was also a decrease in tissuewater content (fresh weight: dry weight) at 100200 molm3 NaCl. The concentration of Na+ and Cl in thetissue increased with increasing salinity of the medium. Mostof the accumulation of these ions occurred by the first weekwhile significant growth inhibition became apparent by onlythe third week of culture. Tissue K+ and Mg2+ decreased withincreasing salinization, the decrease being greater in K+ levels.Levels of Ca2+, however, were maintained throughout the experimentalrange. Key words: Cicer arietinum, NaCl stress, Callus cultures, Ion accumulation 相似文献
12.
WEIMBERG RALPH; LERNER H. R.; POLJAKOFF-MAYBER A. 《Journal of experimental botany》1983,34(10):1333-1346
For determination of the effects of polymyxin B, polymyxin E,or ethylenediamine tetra-acetic acid (EDTA) on plant cell membranes,the rates at which three solutes, K+, P1, and sugar, leakedfrom treated tissue culture cell suspensions of Nicotiana tabacumwere measured. The kinetics of leakage from cells treated witheither of the polymyxins was biphasic, whereas kinetics forcells treated with EDTA was monophasic. Only K+ leaked frompolymyxin-treated cells during the first phase, and all threesolutes leaked during the second phase. The slower first phaseis interpreted as leakage of K+ from the Donnan free space andcytoplasm, and the faster second phase as the leakage of solutesfrom the vacuole. The monophasic kinetics of EDTA treatmentindicated that solutes were leaking simultaneously from cytoplasmand vacuole. Of the divalent cations tested, only Ca++ and Mn++counteracted the effects of polymyxin and EDTA. Ca++ even restoredP1 and sugar uptake. Addition of Mg++ or Sr++ to polymyxin-treatedcells did not stop solute leakage but actually enhanced theleakage rates. A model is presented that suggests that polymyxinor EDTA induces solute leakage by forming pores in plant cellmembranes. The effects of divalent cations on membranes oncethe pores are formed are also discussed. Key words: Polymyxin, EDTA, Nicotiana tabacum, Solute leakage 相似文献
13.
The longitudinally bisected pistil of Lilium longiflorum cv.Hinomoto was shown to be useful for the study of self-incompatibility.When pollen grains of cv. Hinomoto or cv. Georgia were placedon the stigma of the bisected pistil, pollen tube elongationof each cultivar occurred with almost the same time course aswhen placed on the stigmaof the whole pistil. Tube elongation of cv. Hinomoto was retarded after 24 hours(self combination), whereas the tubes of cv. Georgia elongatedwell (cross combination). The selfincompatibility reaction detectedas retardation of pollen tube elongation occurred in all portionsof the inner surface of the stylar canal; it was not restrictedto a specific portion of the style.
1Present address: Laboratory of Pomology, Faculty of Horticulture,Chiba University, Matsudo, Chiba 271, Japan. (Received October 20, 1982; Accepted February 9, 1983) 相似文献
14.
The development of a medium for studying aluminium toxicityin plant cell cultures is described. To prevent the precipitationof Al added to the standard cell culture medium, it was necessaryto lower the phosphate concentration from 1250 mmol m3to10 mmol m3, and the pH from 5.8 to 4-0. Two additionalmodifications were the use of unchelated iron and a reductionin the calcium concentration from 3.0 mol m3 to 0.1 molm3. Since the gelling properties of agar are inhibitedat pH 4.0, cells were cultured on filter paper supported bypolyurethane foam sturated with liquid medium. The only limitationto the growth of plated Nicotiana plumbaginifolia Viv. cellson the modified medium was the reduced phosphate concentration.This was partly overcome by preloading the cellswith phosphate prior to each experiment. In addition, the filterpaper with adhering cells was transferred to fresh medium everysecond day to replenish phosphate, and to re-establish the initialpH of4.0 (which otherwise drifts upward). With the modifiedmedium, Al toxicity was observed in plated N. plumbaginifoliacells at both 200 mmol m3 and 400 mmol m3 Al.There was no toxicity at these Al concentrations when the normalphosphate concentration or pH were restored to the modifiedmedium. Partial alleviation of Al toxicity occurred with restorationof the normal calcium concentration or chelated iron. Chelationof Al with citrate or EDTA also mitigated Al toxicity. In additonto Al toxicity, the modified medium should also prove usefulfor studying other metal toxicities in plant cell culture. Key words: Al toxicity, Cell culture, Nicotiana plumbaginifolia 相似文献
15.
Anthers of Hordeum vulgare cv. Sabarlis at the mid-unicellularpollen stage, pretreated in the excised spike for 14 d at 7°C, dehisce within 24 h of being floated on the surfaceof liquid medium. About half the pollen (1500 grains per anther)is liberated into the medium. If the anthers are then removedand the cultures re-incubated, calluses develop from the shedpollen in high yields. At low anther densities, 10p20(13 x 104 grains) per ml, medium preconditioned by anthersand supplemented with m-inositol (1000 mg 11) is required,but at high densities, 120 anthers (2 x 105 grains) per ml,preconditioning is less important, the cultured anthers themselveshaving a sufficient conditioning influence. Large-scale dissectionof anthers can be avoided by use of drops of medium, the volumebeing increased gradually as culture proceeds. Pollen remainingin the anthers after 3 d gives rise to calluses if isolatedmechanically and cultured in the inositol medium. The use ofshed pollen is seen as particularly valuable for culture inspecies whose anthers are small, tedious to dissect out anddifficult to process without severe damage. 相似文献
16.
Capacity for aluminium uptake depends on brefeldin A-sensitive membrane traffic in tobacco (Nicotiana tabacum L. cv. BY-2) cells 总被引:1,自引:0,他引:1
The relationship between cellular growth and aluminium (Al) uptake was examined by applying brefeldin A, a vesicle transport
inhibitor, to cultured tobacco (Nicotiana tabacum L. cv. BY-2) cells. Cultured cells almost completely lost the capacity for Al uptake when pre-incubated for 1–3 h in a minimal
medium. Pre-incubation also diminished subsequent growth in a culture medium. However, competency for Al uptake (20 μm, pH 4.5) was sustained in a dose-dependent and reversible manner when cells were treated with brefeldin A (10 μm), an inhibitor of Golgi-mediated secretion, prior to and during the incubation in minimal medium.
Received: 24 September 1998 / Revision received: 24 November 1998 / Accepted: 5 December 1998 相似文献
17.
Haploid plantlets were obtained in large numbers in three diploid,24-chromosome species of Nicotiana by culture of anthers ator just past the first pollen mitosis. The three species wereN. Knightiana, N. raimondii, and N. attentiata. Efficiency ofhaploid production varied from about 10 per cent in N. attenuatacultures to 30 and 38 per cent respectively in cultures of N.raimondii and N. Knightiana. H-medium without hormones and standardcultural conditions were used. N. Knightiana appeared to beespecially suitable for haploid studies on account of its highplantlet productivity, low chromosome number, and distinctivekaryotype. 相似文献
18.
The effect of ionophores and tyrocidine on membrane-bound adenosinetriphosphatase (ATPase) activity in epidermal cells from tobacco(Nicotiana tabacum L. cv. Samsun) leaves was investigated. GramicidinS inhibited Mg2$-K$-ATPase activity in the epidermal membraneof tobacco leaves. Its half-maximal inhibition was found at2.4?105 M (under conditions of 370 µg membraneprotein per 2 ml reaction mixture). The degree of inhibitionof the epidermal ATPase was in the following order: tyrocidine>gramicidinS>DCCD>vanadate>DES>gramicidin D, all at 104M. The ionophores, valinomycin, nigericin and salinomycin, inhibitedthe epidermal ATPase activity only slightly or not at all. TheATPase solubilized from the membrane with detergents was negligiblyinhibited by gramicidin S and tyrocidine. Thus, gramicidin Sacts in the manner of tyrocidine rather than as an ionophoreand may disturb the organization of the lipoprotein membrane,which in turn inactivates the membranebound epidermal ATPase. (Received July 13, 1981; Accepted December 4, 1981) 相似文献
19.
K+ efflux from tobacco (Nicotiana tabacum L, cv. Samsun NN)leaf discs into the external medium was increased and the membranepotential (Em) changed in the positive direction with a changein pH from 8.0 to 4.0. Em was affected by the external concentrationof KCl, greatly decreasing with a change in concentration from1 mM to 100 mM. The equilibrium potential of the membrane forK+ (Ek) was decreased in a Nernst fashion with increasing externalconcentrations of KCl. Ek is more positive than Em above ca.50 µM KCl. Most of the experiments were carried out underconditions in which the difference between the electrochemicalpotential for K+ on the inside to the outside of the cell (µkis positive. Thus, K+ may passively flow to the outside of thecells accompanied by the depolarization of the membrane. Abscisic acid (ABA) increased the K+ efflux under conditionsof passive transport. K+ efflux was accelerated with an increasingconcentration of ABA, being maximal at 104 M103M. This acceleration was due to the enhancement of the potassiummotive force (µk/F) which is the force causing the netpassive transport of K+. The membrane potential was decreasedfrom 205 mV to 170 mV by 2 x 104 M ABAwithin 10 min. The depolarization was not transient, being lostfor at least 3 hr. These results show that ABA accelerated passive K+ efflux, whichaccompanied depolarization of the membrane. (Received June 22, 1981; Accepted August 24, 1981) 相似文献
20.
Polypeptide compositions, ATPase characteristics, and the N-1-naphthylphthalamicacid binding capacity of plasma membranes prepared from winterrye (Secale cereale L. cv. Puma) shoots and roots were examinedand compared. Some unique polypeptides were revealed in each plasma membraneby one- and two-dimensional slab gel electrophoresis. A differencewas also detected in glycopeptide compositions. The plasma membranesfrom both organs contained Mg2+-stimulated ATPase exhibitingslightly different properties in the divalent cation specificityand the kinetic constants. The ATPase activities from both organsshowed a similar optimum pH around 6.5, simple Michaelis-Mentensaturation with increasing ATP-Mg concentrations, and littleK+-stimulation at the optimum pH. Both ATPases were inhibitedby orthovanadate, however, the degree of inhibition was a littledifferent in each membrane sample. The specific N-1-naphthylphthalamicacid binding capacity in the shoot plasma membrane was 2.6-foldhigher than that in the root plasma membrane. These results suggest that polypeptide compositions of plasmamembranes vary corresponding with a difference in the physiologicalfunctions of plasma membranes between shoots and roots of winterrye.
1 Contribution No. 2670 from the Institute of Low TemperatureScience. (Received May 17, 1984; Accepted October 9, 1984) 相似文献