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1.
VAN DER KRIEKEN W. M.; VAN ELDIK G.; NIJTMANS L.; CROES A. F.; WULLEMS G. J. 《Journal of experimental botany》1991,42(1):77-80
The accumulation of endogenous cytokinins was studied in pedicelexplants of tobacco (Nicotiana tabacumL.) during regenerationof flower buds in vitro. Maximal bud formation was induced onmedia containing 1.0 mmol m3 of benzyladenine or dihydrozeatin.No buds were formed in the absence of cytokinin. The levelsof dihydrozeatin, zeatin, and the corresponding ribosides weredetermined in explants cultured in the presence or absence ofcytokinin by means of a competitive ELISA technique. In explantsincubated without a cytokinin, only the dihydrozeatin concentrationincreased significantly during the first day of incubation anddecreased during the second day. No increase was observed inexplants incubated in the presence of benzyladenine. The concentrationof dihydrozeatin in these bud-forming explants was only 10 to15% of the concentration built up in explants cultured on dihydrozeatininstead of benzyladenine. This suggests that the endogenouscytokinins only play a minor role in the regeneration of flowerbuds in vitro. Key words: cytokinin, flower bud development, tissue culture, tobacco 相似文献
2.
Potassium-Ammonium Uptake Interactions in Tobacco Seedlings 总被引:6,自引:0,他引:6
SCHERER HEINRICH W.; MACKOWN CHARLES T.; LEGGETT J. EVERETT 《Journal of experimental botany》1984,35(7):1060-1070
Short-term (< 12 h) uptake experiments were conducted with67-week-old tobacco (Nicotiana tabacum L. cv. Ky 14)seedlings to determine absorption interactions between K+ andNH4+. At equal solution concentrations (0.5 mol m3) netK+ uptake was inhibited 3035% by NH4+ and NH4+ uptakewas decreased 924%. Removal of NH4+ resulted in completerecovery in K+ uptake rate, but NH4+ uptake rate did not recoverwhen K+ was removed. In both cases, inhibition of the uptakerate of one cation saturated as the concentration of the othercation was increased up to 0.5 mol m3. The relative effectof K+-NH4+ interactions was not altered when Cl- was replacedwith SO42, but the magnitudes of the uptake rates wereless in the absence of Cl-. The Vmax for NH4+ uptake was reducedfrom 128 to 105 µmol g1 dry wt. h1 in thepresence of 0.5 mol m3 K+ and the Km for NH4+ doubledfrom 12 to 27 mmol m3 in the presence of K+. The resultsof these K+-NH4+ experiments are interpreted as mixed-noncompetitiveinteractions. However, an enhanced efflux of K+ coupled to NH4+influx via an antiporter cannot be ruled out as contributingto the decrease in net K+ uptake. Key words: Nicotiana tabacum, K+, NH4+, Uptake interactions 相似文献
3.
CROES A. F.; CREEMERS-MOLENAAR TINEKE; VAN DEN ENDE G.; KEMP ANKE; BARENDSE G. W. M. 《Journal of experimental botany》1985,36(11):1771-1779
Croes, A. F., Creemers-Molenaar, T., van den Ende, G., Kemp,A. and Barendse, G. W. M. 1985. Tissue age as an endogenousfactor controlling in vitro bud formation on explants from theinflorescence of Nicotiana tabacum L.J. exp. Bot. 36:17711779. The in vitro formation of generative buds was studied on explantsfrom flower and fruit stalks and from internodes of the floralramifications of tobacco. A floral gradient was found to existalong the axis of the branch. The gradient concerns the numberof flower buds formed in vitro and is present in both typesof tissues. The number of flower buds is greater on tissuesfrom the apical than from the basal portion of the branch. Thecapacity to generate these buds is largely determined by tissueage at the moment of the excision. Consequently, the gradientmoves along the axis during the outgrowth of the inflorescence. The alternative possibility that some apex-derived stimuluspredetermines the morphogenetic capacity of the tissue priorto excision is excluded by the observation that the gradientremains virtually unaltered if the apex is removed one weekbefore the onset of culturing. Auxin affects the floral gradient Increasing the auxin concentrationin internode tissue culture causes a steeper gradient of flowerbud generation by almost completely abolishing bud formationon older tissues. Key words: Auxin, flower buds, gradient, tissue culture, tobacco 相似文献
4.
Growth and Osmotic Adjustment of Cultured Suspension Cells from Alternanthera philoxeroides (Mart.) Griseb After an Abrupt Increase in Salinity 总被引:2,自引:0,他引:2
BALAGTAS-BUROW GLORIA E.; MORONEY JAMES V.; LONGSTRETH DAVID J. 《Journal of experimental botany》1993,44(3):673-679
We have developed a cell suspension culture from alligator weed(Alternanthera philoxeroides [Mart.] Griseb), a C3 member ofthe Amaranthaceae. Intact plants of alligator weed can growat 400 mol m3 NaCl. Growth of alligator weed suspensionswas compared to growth of tobacco (Nicotiana tabacum L. cv.Wisconsin 38) suspensions after subculture to 200 mol m3NaCl. Fresh weight and cell density of salt-treated alligatorweed suspensions more than doubled by 7 d after subculture,but the fresh weight of salt-treated tobacco suspensions didnot double during the 21 d experiment. Correspondingly, cellviability dropped from about 90% to 77% in alligator weed andto 41% in tobacco, at 1 d after subculture to 200 mol m3NaCl. The symplastic volume of alligator weed cells declined36% by 2 h after subculture to 200 mol m3 NaCl, but cellcontents became iso-osmotic with the media at this point. Between2 h and 6 h there was a further decrease in osmotic potential,an increase in turgor potential and a partial recovery of symplasticvolume. Turgor potential was similar to that in control cellsby 24 h, indicating significant osmotic adjustment. Turgor potentialsremained similar in both treatments from 24 h through 21 d butthe average symplastic volume of salt-treated cells was 11 %less than in control cells. Therefore, alligator weed suspensioncells exhibit a rapid recovery of water balance and cell growthafter an abrupt and substantial increase in salinity. Key words: Cell culture, growth, osmotic adjustment, salinity, turgor potential 相似文献
5.
The state of determination of the two emergent carpel primordiaof Nicotiana tabacum was tested. Carpel rudiments were excisedand cultured singly or in pairs. The basal medium was that ofLinsmaier and Skoog, supplemented with 1.0 mg 11 kinetin.Over the ensuing 4 week period, whole differentiated pistilsformed from the pairs and half pistils grew from the singlecarpels. It is concluded that these emergent organs show a certaindegree of autonomy and that they may have been determined atthe time of isolation. Nicotiana tabacum L, tobacco, carpel, organ determination, tissue culture, morphogenesis 相似文献
6.
DNA polymerases were purified several hundred-fold from the10 000 x g soluble (polymerase I) and particulate (polymeraseIII) fractions prepared from virus PBCV-1 infected ChlorellaNC64A extracts. Both DNA polymerases exhibited optimal activitywith activated calf thymus DNA at pH 8.5. DNA polymerase I required3.0 mol m3 MgSO4 and 150 to 250 mol m3 KCl foroptimum activity whereas, DNA polymerase III required 2.0 molm3 MgSO4 and 150 mol m3 KCl. Both enzymes wereinhibited by pyrophosphate, actinomycin D, ethidium bromide,dideoxythymidine triphosphate, and N-ethylmaleimide but wererelatively insensitive to aphidicolin. DNA polymerase I differedfrom DNA polymerase III in its response to cations (particularlyNH4Cl), elution from a DEAE cellulose column, and molecularweight. Key words: Algal virus, DNA polymerase, Chlorella 相似文献
7.
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
8.
Mangat, B. S. and Janjua, S. 1987. Cyclic nucleotides and invitro plant cultures. I. Induction of organogenesis in tobacco(Nicotiana tabacum) callus cultures.J. exp. Bot. 38:20592067. The possibility that cyclic nucleotides have a mediatory rolesimilar to cytokinins in plant tissue cultures was examined.Calli obtained from tobacco pith tissue were incubated on growthmedia supplemented with either cyclic AMP, cyclic GMP, adenosineor guanosine, in concentrations ranging from (mg dm3)0 to 2·0 together with 2·0 mg dm3 of IAA.Results were compared with identical calli grown on media containingcomparable amounts of kinetin and IAA. Increase in callus growthwas observed on all media containing cyclic AMP, cyclic GMP,adenosine, guanosine or kinetin. Adenosine or guanosine didnot promote organogenesis. Low concentrations (0·02 and0·05 mg dm3) of kinetin stimulated extensive rootdevelopment. Some root formation was also elicited with higheramounts of cyclic AMP (0·1 and 0·2 mg dm3)or cyclic GMP (0·2 and 0·5 mg dm3). Bothkinetin and cyclic GMP promoted shoot differentiation. However,in contrast to kinetin, cyclic GMP induced organogenesis atlower concentrations (0·02 and 0·1 mg dm3).The addition of 2·0 mg dm 3 of cyclic AM P toIAA-free growth media elicited shoot differentiation. This wasalso the case with a similar concentration of kinetin or cyclicGMP. Results suggest cytokinin activity for the two cyclic nucleotides. Key words: Tobacco, Nicotiana tabacum, tissue culture, cyclic nucleotides, cyclic AMP, cyclic GMP organogenesis 相似文献
9.
Solutions of oestrone, oestrone-phosphate, oestrone-sulphate,oestradiol and oestradiol-sulphate in the concentration range103 mol m3 to 107 mol m3 had noobservable morphological or anatomical effects on adventitiousroot formation in Phaseolus vulgaris hypocotyl, epicotyl andprimary leaf cuttings. Oestradiol-sulphate and oestrone-sulphatetreatments at 0.1 mol m3 significantly inhibited rootingin hypocotyls, and the inhibition was almost complete in epicotylsand primary leaves. In the latter, anomalous development ofvascular tissues was noted. However, neither oestrone-phosphateat 0.1 mol m3 nor direct application of up to 100 µgof the oestrogens to apices or primary leaves of explants modifiedthe pattern of root formation. The results are discussed withreference to the distributive and metabolic fates of the appliedsubstances. Phaseolus vulgaris L., bean, adventitious roots, steroidal oestrogens, translocation 相似文献
10.
Effect of Salinity on Growth, Nodulation and Nitrogen Yield of Chickpea (Cicer arietinum L.) 总被引:2,自引:0,他引:2
Chickpea cultivar ILC 482 was inoculated with salt-tolerantRhizobium strain Ch191 in solution culture with different saltconcentrations added either immediately with inoculation or5 d later. The inhibitory effect of salinity on nodulation ofchickpea occurred at 40 dS m1 (34.2 mol m3 NaCl)and nodulation was completely inhibited at 7 dS m1 (61.6mol m3 NaCl); the plants died at 8 dS m1 (71.8mol m3 NaCl). Chickpea cultivar ILC 482 inoculated with Rhizobium strain Ch191spcstrwas grown in two pot experiments and irrigated with saline water.Salinity (NaCl equivalent to 14 dS m1) significantlydecreased shoot and root dry weight, total nodule number perplant, nodule weight and average nodule weight. The resultsindicate that Rhizobium strain Ch191 forms an infective andeffective symbiosis with chickpea under saline and non-salineconditions; this legume was more salt-sensitive compared tothe rhizobia, the roots were more sensitive than the shoots,and N2 fixation was more sensitive to salinity than plant growth. Key words: Cicer arietinum, nodulation, N2 fixation, Rhizobium, salinity 相似文献
11.
Ethylene and Ethane Production in 2,4-D Treated and Salt Treated Tobacco Tissue Cultures 总被引:1,自引:0,他引:1
Gas chromatography was used to measure ethylene (ethene) andethane production by tobacco (Nicotiana tabacum cv. Wisconsinno. 38) callus tissues grown on media containing inorganic saltsaccording to Murashige and Skoog (1962), sucrose, myo-inositol,thiamine-HCl kinetic according to Linsmaier and Skoog (1965),and either 2,4-dichiorophenoxyacetic acid (2,4-D) in the range0100 mgl1 or 2 mgl1 indoi-3-ylacetic acidplus NaCl in the range 0200 Meq l1. Ethylene productionrates were high (> 500 nl h1 g1 fresh weight)initially in all treatments. Subsequently, ethylene productiondeclined in rapidly growing cultures but remained high in moderatelyand severely 2,4-D (> 0·5 mgl1) stressed andin severely NaCl (150 Meql1) stressed cultures. Highinitial rates of ethane production (> 200 nl h1 g1fresh weight) were obtained under conditions of severe stresscaused by 2,4-D or NaCl but not in control or moderately inhibitedcultures. With further incubation ethane production declinedin the severely stressed cultures. It is concluded that ethyleneproduction can be used as an index of moderate 2,4-D stressand severe NaCl stress by virtue of the high persisting ratesof ethylene production in stressed cultures. Ethane productioncan be used as an early index of severe stress caused by either2,4-D or NaCl in vitro. Nicotiana tabacum L., tobacco, ethylene, ethenen, ethane, 2,4-dichlorophenoxyacetic acid, auxin, stress, callus tissue 相似文献
12.
The effects of 0, 50, 100, 200, 300, 400 and 500 mol m3NaCl on growth and ion accumulation in the succulent, coastalhalophyte Sarcocornia natalensis (Bunge ex Ung.-Sternb.) A.J. Scott were investigated. Increase in salinity from 0 to 300 mol m3 NaCl stimulatedproduction of fresh, dry, and organic dry mass, increased succulenceand shifted resource allocation from roots to shoots. Growthwas optimal at 300 mol m3 and decreased with furtherincrease in salinity. Water contributed to a large proportion of the increase in freshmass. Inorganic ions, especially Na+ and Cl contributedsubstantially to the dry mass. At 300 mol m3 NaCl inorganicions contributed to 37% of total dry mass and NaCl concentrationin the shoots was 482 mol m3. Expressed sap osmotic potentialsdecreased from 2.10 to 3.95 MPa as salinity increasedfrom 0 to 300 mol m3 NaCl. Massive accumulation of inorganicions, especially Na+ and Cl, accounted for 86% of theosmotic adjustment at 300 mol m3 NaCl. Salinity treatments decreased the concentrations of K+ in shoots.Plant Na+ :K+ ratios increased steadily with salinity and reacheda maximum of 16.6 at 400 mol m3 NaCl. It is suggested that the exceptional salt tolerance of S. natalensisis achieved by massive inorganic ion accumulation which providessufficient solutes for osmoregulation, increased water fluxand turgor-induced growth. Key words: Sarcocornia natalensis, salt tolerance, halophyte 相似文献
13.
14.
Explants of stem, leaves, roots, and cotyledons from etiolatedaxenically grown Vicia faba seedlings were cultured on a rangeof media. Shoot organogenesis was only obtained with nodal stemand cotyledonary node explants when cultured on MS medium with3% sucrose, 2.0 mg 11 BAP and 02 mg 11 NAA. Callusproliferation accompanied shoot organogenesis from nodal stemexplants. Successive subculture of nodal stem callus resultedin proliferation of regenerative callus which contained severalshoot bud initials. The capacity for shoot regeneration fromthis callus was maintained for 9 months. Histological studiesreveal de novo formation of meristematic centres in callus andtheir further development into bud primordia. High frequencyrooting of these adventitious shoots was obtained on half-strengthMS medium with 1.5% sucrose, 0.1 mg 11 NAA and 0.5 mg11 kinetin. Key words: Vicia faba, adventitious shoots, axillary shoots, de novomeristem formation, organogenesis, tissue culture 相似文献
15.
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
16.
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
17.
Proline and Polyamine Involvement in Chilling Tolerance of Maize Suspension Cultures 总被引:9,自引:0,他引:9
We have assessed the effect of various medium supplements inpromoting the ability of maize (Zea mays L.) inbred FR27rhmsuspension cultures to grow following a period of 4 °C chillingstress. Following a 4 week exposure to 4 °C in culture mediumwithout proline, no cell growth occurred upon subsequent incubationat 28°C for 2 weeks. This inhibition was reversed when 3to 48 mol m3 proline or 0.1 mol m3 putrescineor 0.01 mol m3 spermidine were present in the mediumduring the chilling stress. On the other hand, suspensions weremade more sensitive to 4°C by blocking polyamine biosynthesiswith 1.0 mol m3 methylglyoxal bis (guanylhydrazone) (MGBG)or a combination of 1.0 mol m3 difluoromethylornithine(DFMO) and 1.0 mol m3 difluoromethylarginine (DFMA).The addition of 10 mol m3 putrescine to the suspensioncontaining DFMO and DFMA prevented the increased chilling sensitivity.Electrolyte leakage studies conducted to assess membrane integrityafter 4 weeks at 4°C and a 2 week regrowth period showedthat cells treated with no polyamines (control), 0.01 mol m3spermidine, 1.0 mol m3 putrescine, or 1.0 mol m3MGBG lost 43, 32, 14, and 100% of the total electrolyte pool,respectively. These results suggest that proline and polyaminesare beneficial for inducing chilling tolerance in FR27rhm suspension. Key words: Proline, polyamine, chilling stress 相似文献
18.
Salt Tolerance in the Triticeae: Leymus sabulosus 总被引:1,自引:0,他引:1
Elymus dahuhcus, Leymus giganteus, L. angustus, L. sabulosusand, to a lesser extent, L. triticoides, were found to tolerate200 mol m3 NaCl in solution culture. Elymus dahuricusdiffered from the Leymus species in its ion-uptake characteristics,showing a greater uptake of Cl and Na and a greater loss ofK from the shoots. In a more detailed experiment on Leymus sabulosusit was found that transpiration rates altered rapidly in responseto changes in external salinity whereas the accumulation ofNa and Cl in the leaves exhibited a lag of several days. Insalt stressed L. sabulosus Cl partially replaced the high levelsof nitrate found in the leaves of control plants. Glycinebetainelevels increased in the leaves from 8.0 mol m3 plantsap in the controls to 28 mol m3 plant sap at 250 molm3 NaCl. Key words: Salt stress, Transpiration, Solute accumulation, Leymus 相似文献
19.
Endogenous abscisic acid contents were measured by gas-liquidchromatography in shoots of Suaeda maritima growing both inthe steady state over a range of salinities and over a time-coursefollowing an increase in the culture solution salinity of betweenapproximately 100 and 400 mol m3 NaCl. In steady-stateplants, the ABA content was maximal in the absence of salt at41 ng g1 fr. wt., declining to a minimum at 200 mol m3NaCl of 24 ng g1 fr. wt. Increase of culture solutionsalinity resulted in a marked increase in shoot ABA which wasmaximal after 6 h or 24 h in plants previously growing at 200mol m3 NaCl and in the absence of salt, respectively.Additionally, culture solution water potentials were loweredby 1.0 MPa (equivalent to raising the salt concentration byaround 200 mol m3); this resulted in a similar increasein endogenous ABA content to that brought about by an iso-osmoticsalt increase. Results are discussed in relation to the possiblerole of ABA in halophyte salt tolerance mechanisms. Key words: Suaeda, halophyte, abscisic acid, salt tolerance 相似文献
20.
In vitro culture of Picea sitchensis (Bong.) Carr. needle explantson a number of basal culture media indicated that a complexmixture of organic additives was neither essential nor stimulatory.Adventitious bud production occurred at inorganic nitrogen levelsof 1560 x 103M and 7.530 x 103 Min the adventitious bud induction and elongation media, respectively,when a well-balanced ratio of NH4+:NO3 was maintained.However, necrosis was increased at the highest level of inorganicnitrogen. Organogenesis was more sensitive to changes in theratio of NH4+:NO3. Complete replacement of NH4+ withNO3 during the adventitious bud induction passage severelyinhibited organogenesis, indicating that a reduced form of nitrogenmay be essential for adventitious bud differentiation. Conversely,a high proportion of NH4+ in either the adventitious bud inductionor elongation medium increased tissue necrosis and inhibitedbud induction, reflecting the potential toxicity of this ion.Explants from different individual trees were found to varyconsiderably in their morphogenetic responses, but NH4+:NO3ratios of 1:5 or 1:2 were o ptimal for all individual treeswhich developed adventitious buds from needle cultures. Picea sitchensis, Sitka spruce, tissue culture, nitrogen 相似文献