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1.
Effect of Salt Stress on Callus Cultures of Oryza sativa L. 总被引:1,自引:0,他引:1
Kavi Kishor, P.B 1988. Effect of salt stress on callus culturesof Oryza sativa L.. exp. Bot 39 235240 Callus cultures of rice adapted to grow under increasing NaClstress were found to accumulate considerable amounts of freeproline, compared with unadapted cells. Salt-adapted cells grownfor 10 passages (25 d each) on NaCl-free medium accumulatedproline on re-exposure to salt as did cells which were growncontinuously on NaCl. On replacing NaCl (100 mol m3)with 100 mol m3 of KC1, fresh and dry weights as wellas free proline content of salt-adapted callus declined comparedto that attained on 100 mol m3 NaCl medium. However,equimolar concentrations of NaCl and KC1 (when added together)produced an increase in growth and free proline accumulationin salt adapted callus. Omission of Ca2+ from the growth mediuminhibited the growth of salt-adapted cells in the presence ofNaCl, while it had little effect on the growth of non-adaptedcells in the presence of NaCl. ABA increased the fresh and dryweights of the non-adapted callus only in the presence of 200mol m3 of NaCl but not in the absence of NaCl. ABA failedto evoke the same response in salt adapted cells in the presenceof the salt. Tissues exhibited good growth under inhibitorylevels of NaCl (500 mol m3) only when glycine betaine,choline and proline were added to the medium but showed no growthin the presence of sarcosine, glycine and dimethylglycine. Key words: Oryza saliva, callus cultures, NaCl stress 相似文献
2.
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
3.
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
4.
UNNIKRISHNAN S K.; PRAKASH L.; JOSEKUTTY P. C.; MEHTA A. R. 《Journal of experimental botany》1991,42(3):401-406
The effect of NaCl salinity on growth and development of somaticembryos of Sapindus trifoliatus L. was examined. Incorporationof 25 and 50 mol m3 NaCl into the medium greatly increasedthe growth and development of somatic embryos and both theseconcentrations favoured the production of secondary embryoids.However, supplementation of 100 mol m3 NaCl to the mediumdid not have any significant effect on the growth and developmentof somatic embryos. On the other hand, the culturing of proembryostructures in medium containing 200 mol m3 NaCl resultedin complete death within 7 d of salt exposure. Analysis of somatic embryos revealed that, upon salinization,they accumulated Na+ and Cl in significant amounts butthe content of Na+ was much less compared to that of Cl.Addition of NaCl (up to 50 mol m3) in the medium resultedin a considerable increase in the K+ content of somatic embryos.The content of proline in somatic embryos, however, increasedsubstantially in response to salinization. The amount of freesterols, steryl glycosides, steryl esters, and phospholipidsalso rose to higher values in salt-affected somatic embryos.The results suggest that somatic embryos of S. trifoliatus cantolerate concentrations of NaCl up to 100 mol m3 withoutaffecting growth and that they have sufficient cellular mechanismsto tolerate salinity at relatively high levels. Key words: Salinity, somatic embryo, sterols, phospholipids 相似文献
5.
Spatial and Temporal Aspects of Growth in the Primary Root of Cotton Seedlings: Effects of NaCl and CaCl2 总被引:1,自引:0,他引:1
Seedlings of cotton (Gossypium hirsutum L. cv. Acala SJ-2) weregrown in modified Hoagland nutrient solution with various combinationsof NaCl and CaCl2. Marking experiments and numerical analysiswere conducted to characterize the spatial and temporal patternsof cotton root growth at varied Na/Ca ratios. At 1 mol m3Ca, 150 mol m3 NaCl reduced overall root elongation rateto 60% of the control, while increasing Ca to 10 mol m3at the same NaCl concentration restored the elongation rateto 80% of the control. Analysis of the spatial distributionof elongation revealed that the presence of 150 mol m3NaCl in the medium shortened the growth zone by about 2 mm fromthe approximate 10 mm in the control and also reduced the relativeelemental elongation rate (i.e. the longitudinal strain rate,defined as the derivatives of displacement velocity of a cellularparticle with respect to position on root axis). Supply of 10mol m3 Ca at the high salt condition restored partiallythe relative elemental elongation rate, but not the length ofthe growth zone. Compared to the control, the growth trajectoriesshowed that at 1 mol m3 CaCl2 it took more time for acellular particle to move through the growth zone at 150 molm3 NaCl, while at 10 mol m3 CaCl it took lesstime and there was no difference between the NaCl treatments Key words: Gossypium hirsutum, salinity stress, root growth kinematics 相似文献
6.
7.
Clipson, N. J. W. 1987. Salt tolerance in the halophyte Suaedamaritima L. Dum. Growth, ion and water relations and gas exchangein response to altered salinity.J. exp. Bot. 38: 19962004. Shoot and root fresh and dry weights and shoot sodium, chlorideand potassium contents were measured and shoot relative growthrates calculated in seedlings of Suaeda maritima over a periodof 11 d following a raising of culture solution salinity from0 to 200 mol m3 NaCl. Growth, growth rates and sodiumand chloride contents, as compared to plants growing in theabsence of salt were increased whilst potassium contents declined.Shoot sodium accumulation rate and the rate of transport ofsodium from root to shoot, osmotic potential, and rates of photosynthesisand transpiration were also measured for up to 72 h after transferof plants originally growing at 0 and 200 mol3 NaCl to200 and 400 mol m3 NaCl respectively. Ion uptake andtransport rates were maximal 6-12 h after transfer and thendeclined to new steady-state levels within 48 h; osmotic potentialswere lowered over a 72 h period on average by approximately1·0 MPa; and after 9 h photosynthetic and transpirationrates were reduced by about 20percnt; and 30% respectively.Results are discussed in terms of the ability of halophytesto adjust to fluctuating salinity and to salt tolerance mechanismsin general. Key words: Suaeda maritima, salinity, gas exchange, growth, ion and water relations 相似文献
8.
Vicia faba cv. Maris Bead was grown either on fixed nitrogenor on ammonium nitrate. After 4 weeks growth, nutrient solutionswere supplemented with 50, 75 and 100 mol m3 NaCl for15 d. Five harvests were made at weekly intervals, beginningat 4 weeks. Effects of salinity were directly related to dose,plant growth (fresh and dry weight) being depressed in bothN-fixing and N-fertilized plants. The number of nodules perplant and the proportion of those formed which developed intothe active nitrogen fixing state were depressed by salt stress.Increased size of nodules in salt-stressed plants only partlycompensated for the lower specific nitrogenase activity. Theeffects of salinity on plant nitrogen content were more pronouncedon N-flxing than on N-fertilized plants. The former took upmore Na+ and Cl than the latter: the implications ofthis and of ionic imbalance are discussed. Key words: Vicia faba, Growth, Salt stress, Nodulation 相似文献
9.
Following 20 d of exposure to 75 or 150 mol m3 NaCl Sorghumbicolor (L.) Moench plants become capable of growing in mediumcontaining 300 mol m3 NaCl. Control plants, which havenot been pretreated, or plants pretreated for less than 20 ddie within 2 weeks when exposed to 300 mol m3 NaCl. Weconsider this induction of a capacity to survive in and toleratea high NaCl concentration as an adaptation to salinity. We suggestthat adaptation to salinity is more than osmotic adjustmentand that it takes longer to develop than osmotic adjustment.Concomitantly with the appearance of the ability to grow inhigh salinity, adaptation also comprises the development ofa capacity to regulate internal Na+ and Cl concentrations,even when external salinity is high. Shoot mean relative growthrates are similar for both control plants and for adapted plantsgrowing in 300 mol m3 NaCl, although their shoot Na+and Cl concentrations are quite different. Based on thesedata, we propose that adaptation of Sorghum to high salinityresults from a modulation of genome expression occurring duringextended exposure to non-lethal NaCl concentrations. Key words: Sorghum bicolor (L.) Moench, NaCl, salt tolerance, adaptation to salinity 相似文献
10.
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
11.
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
12.
Ion Transport in Suaeda maritima: Its Relation to Growth and Implications for the Pathway of Radial Transport of Ions across the Root 总被引:5,自引:0,他引:5
The ion relations of the halophytc Suaeda maritima are described.When plants grew in 340 mol m3 sodium chloride (176MPa) leaf solute potentials decreased, and were sustained around25 MPa Inorganic ion concentration (mostly of sodiumchloride) accounted for this. Comparable shoot ion concentrationsof potassium, nitrate and sulphate occurred when plants grewon different salinity types characterized by these ions. Netsodium transport and shoot sodium concentration increased dramaticallywith increases in external sodium chloride concentration upto 85 mol m3; thereafter, further increases in externalsodium chloride concentration had relatively little effect uponeither shoot sodium concentration or upon net transport of sodiumto the shoot. The net transport of sodium plus potassium onlydoubled when the external concentration of sodium plus potassiumincreased from 24 to 687 mol m3 Shoot ion concentrationswere remarkably constant with time, external concentration andsalinity type. The membrane flux rates and symplasmic ion concentrations neededto sustain the observed net transport of sodium (of some 10mmol g1 dry wt. of roots d1) are calculated fromanatomical and stereological data for the root system of thisspecies. The minimum net sodium chloride flux to load the symplasmwould be 260 nmol m2s1 if the whole cortical andepidermal plasmalemmal surface area were used uniformly, butthe flux rate required would be 3000 nmol m2s1if uptake took place only at the root surface. A flux rate ofat least 1000 nmol m2s1 is needed between symplasmand xylem. The symplasmic concentration of NaCl would be atleast 80 mol m3. It is argued (1), that both symplasmicand xylem loading are likely to be passive processes mediatedby ion channels rather than active carriers, (2), that net iontransport at 340 mol m3 sodium chloride is close to themaximum which is physiologically sustainable and (3), that growthof this halophyte is limited by NaCl supply from the root. Key words: Suaeda maritima, halophyte, salinity, roots, radial ion transport 相似文献
13.
Ricinus communis L. (castor bean) plants were grown in the absence(control) and in the presence of 100molm3NaCl with areciprocal split-root system, in which K+ was supplied to oneand NO3 to the other part of the root system. In theseplants shoot and, to a lesser extent, total root growth wereinhibited compared to plants with non-split roots. Without andwith NaCl, growth of roots receiving NO3 but noK+ (minusK/plus N-roots) was substantially more vigorous thanunder the reverse conditions (plus K/minus N-roots1).100mol m3 NaCl inhibited growth of minus K/plus N-roots1to the same extent as that of non-split roots, indicating thatexternally supplied K+ was not required for root growth undersaline conditions. In growth media without added K+ the rootdepleted the external low K + levels resulting from chemicalsdown to a minimum value Cmln (1.0 to 1.4 mmol m3); inthe presence of 100 mol m3 NaCl, Cmin, was higher (1018mmol m3) and resulted from an initial net loss of K +.Cmin, was pH-dependent The distribution of K+, Na+ and Mg2+along the root was measured. In meristematic root tissues, K+ concentrations were scarcely affected by external K+ or byNaCl, where Na + concentrations were low, but somewhat elevatedat low external K+ and/or high NaCl. In differentiated, vacuolatedtissues K + concentrations were low and Na+ concentrations high,if K + was not supplied externally and/or NaCl was present.The longitudinal distribution of ions within the root was usedto estimate cytoplasmic and vacuolar ion concentrations. Thesedata showed a narrow homoeostasis of cytoplasmic K+ concentrations(100140 mol m3) independent of external K + supplyeven in the presence of 100 mol m 3 NaCl. CytoplasmicNa + concentrations were maintained at remarkably low levels.Hence, external K+ concentrations above Cmin, were not requiredfor maintaining K/Na selectivity, i.e. for controlling Na+ entry.The results are discussed with regard to mechanisms of K/Naselectivity and to the importance of phloem import of K+ forsalt tolerance of roots and for cytoplasmic K+ homoeostasis. Key words: Ricinus communis, nitrate, potassium, root (split-root), salt tolerance, phloem transport 相似文献
14.
Soybean [Glycine max (L.) Merrill] seeds and cotyledons weregrown in an in vitro culture system to investigate the relationshipsbetween cell expansion (net water uptake by the seed) and drymatter accumulation. Seeds or cotyledons grown in a completenutrient medium containing 200 mol m3 sucrose continueddry matter accumulation for up to 16 d after in planta seedsreached physiological maturity (maximum seed dry weight). Seedor cotyledon water content increased throughout the cultureperiod and the water concentration remained above 600 g kg1fresh weight. These data indicate that the cessation of seeddry matter accumulation is controlled by the physiological environmentof the seed and is not a pre-determined seed characteristic.Adding 600 mol m3 mannitol to the medium caused a decreasein seed water content and concentration. Seeds in this mediumstopped accumulating dry matter at a water concentration ofapproximately 550 g kg1. The data suggest that dry matteraccumulation by soybean seeds can continue only as long as thereis a net uptake of water to drive cell expansion. In the absenceof a net water uptake, continued dry matter accumulation causesdesiccation which triggers maturation. Key words: Glycine max (L.) Merrill, solution culture, duration of seed growth, water content, dry matter accumulation 相似文献
15.
Kinetics of Root Elongation of Maize in Response to Short-Term Exposure to NaCl and Elevated Calcium Concentration 总被引:9,自引:0,他引:9
CRAMER GRANT R.; EPSTEIN EMANUEL; LAUCHLI ANDRE 《Journal of experimental botany》1988,39(11):1513-1522
To study the effect of salt (NaCl) on root elongation we developeda device that measures this effect by means of a Linear VariableDifferential Transformer (LVDT). To test the efficacy of thedevice we performed experiments demonstrating that (a) ratesof elongation of primary maize (Zea mays L.) roots were comparableto elongation rates of primary roots growing freely in solutionculture; and (b) chilling and low O2 concentrations of the solutionelicited the expected responses. Inhibition of root elongation by 75 mol m3 NaCl was gradual.At an iso-osmotic concentration, mannitol did not inhibit rootgrowth, suggesting that the inhibition was not due to osmoticfactors but rather to effects of salt on metabolism. The additionof supplemental Ca (10 mol m3) ameliorated this stressfulcondition. Timing of the application of Ca was critical. Treatmentwith Ca after addition of NaCl only partially restored growth,but pretreatment with Ca completely prevented the inhibitionof growth by salt stress. Key words: Root growth, Zea mays L., salinity 相似文献
16.
Possible reasons for relative salt stress tolerance in nodules of white lupin cv. Multolupa 总被引:5,自引:2,他引:3
Fernndez-Pascual M.; de Lorenzo C.; de Felipe M.R.; Rajalakshmi S.; Gordon A.J.; Thomas B.J.; Minchin F.R. 《Journal of experimental botany》1996,47(11):1709-1716
The effects of different NaCl concentrations on the growth andnitrogen fixation activity of white lupin (Lupinus albus [L.])was studied over a 6 d period. Plant growth parameters, photosynthesisand shoot respiration were unaffected by NaCl concentrationsup to 150 mol m3. However, nitrogenase activity decreasedwith increased NaCl concentration up to 100 mol m3, whilstthe O2 diffusion resistance increased with 100 mol m3NaCl, but showed no further change when 150 mol m3 NaClwas applied for 6 d. Increases in NaCl concentration decreasednodular starch content while increasing sucrose content, suggestingan osmotic regulation. These changes were associated with a77% decrease in sucrose synthase activity. The effect on theO2 diffusion resistance was paralleled by changes in glycoproteincontent of the nodules, as determined by immunogold localizationand ELISA. X-ray microanalysis studies of nodules showed that,following a 6 d exposure to 150 mol m3 NaCl, Na+ ionswere largely excluded from the infected zone, whilst only lowlevels of Cl- ions penetrated into this region. Na+ entry intoroots and leaves was also at a low level. Leghaemoglobin contentdecreased with saline stress, as did superoxide dismutase; whichdecreased by 36% following exposure to 100 mol m3 saltfor 6 d. These results are discussed in relation to the relativesalt tolerance of the Multolupa/ISLU-16 symbiosis. Key words: Salt stress, nodules, nitrogen fixation, oxygen diffusion, carbohydrates, Lupinus albus 相似文献
17.
Treatment of Sorghum bicolor (L.) Moench, cv. 610, with abscisicacid (ABA) during the first week of sahnization with 150 molm3 NaCl induced enhancement of growth and acceleratedadaptation to high salinity (300 mol m3 NaCl) Adaptationis defined as the development of the ability of the plant tosurvive, grow, and set seeds upon exposure to a NaCl concentrationwhich is lethal for the unadapted plant In the absence of ABAthe saline pretreatment requires 20 d for the development ofadaptation (Amzallag et al., 1990), with ABA treatment the sameresult is achieved within approximately one week The exposureof the plants to non-lethal salinity (150 mol m3 NaCl)apparently triggers a transient sensitivity to ABA lasting forabout 8 to 10 d following the beginning of sahnization Thisperiod coincides with an increase in leaf PEP carboxylase activitywhich seems to occur faster if the plants are treated with ABA.Exogenous ABA-induced enhancement of growth and control of shootNa+ concentration, occur at a lower ABA concentration (10 mmolm3) than the induction of adaptation to salinity whichoc curs at 40 mmol m3 or above. The lowered shoot Na+concentration which is induced by a low ABA concentration isnot sufficient to induce survival of the plants in high salinity(300 mol m3 NaCl). Key words: Growth, adaptation to salinity, ABA 相似文献
18.
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
19.
STOREY R.; GORHAM J.; PITMAN M. G.; HANSON A. D.; GAGE D. 《Journal of experimental botany》1993,44(10):1551-1560
Melanthera biflora (Asteraceae) is a moderately salt-tolerantplant from the Indo-Pacific region. In laboratory studies itsgrowth was inhibited by salt above 50 mol m3, but itwas able to survive salinities approaching that of seawater,namely 400 mol m3. Shoot potassium concentrations weremaintained over a range of salinities up to 400 mol m3,while sodium and chloride accumulation followed closely theincrease in external osmotic pressure. In contrast, the increasein osmotic pressure of the leaf sap of Melanthera biflora, subjectedto water stress, was due mainly to a decrease in the ratio offresh weight/dry weight. 3-dimethylsulphoniopropionate (3-DMSP)and glycinebetaine were identified by fast atom bombardmentmass and 1H -NMR spectroscopy, with 3-DMSP being the main oniumcompound and glycinebetaine absent in some accessions. Onium(quaternary ammonium and/or tertiary sulphonium) compounds andproline increased during salt and water stress due mainly toa decrease in the fresh weight/dry weight ratio of tissue, althoughpart of the increase in salt-stressed tissue was due to an increasein the accumulation of the onium compound. This salt-inducedincrease in 3-DMSP was inhibited in conditions of low sulphursupply and there was no compensatory increase in proline. Key words: Melanthera biflora, Asteraceae, salinity, glycinebetaine, 3-dimethylsulphonioproprionate 相似文献
20.
Determination of Volume of Dunaliella Cells by Lithium Dilution Measurements and Derivation of Internal Solute Concentrations 总被引:1,自引:0,他引:1
A method has been developed to measure the cell volume of theunicellular green alga Dunaliella parva 19/9 using Li+ measurementsonly. Concentrations of internal solutes can also be calculatedif they are assayed in the same samples as Li+. We found thatD. parva cells grown in 0.4 kmol m3 NaCl have an averageaqueous cell volume of 65.1 ?2.9 µm3, a K+ concentrationof 126?6 mol m3, a Na+ concentration of 11?11 mol m3and a glycerol concentration of 615?27 mol m3 (n= 12).Algae grown in 1.5 kmol m3 NaCl have an average aqueouscell volume of 131 ?7.5 µm3, a K+ concentration of 109?4mol m3, a Na+ concentration of 10?39 mol m3 anda glycerol concentration of 1 425?59 mol m3 (n = 12).These results indicate that D. parva cells adapted to high salinitieshave larger cell volumes than those adapted to lower salinities.However, there is no evidence for a significant difference ininternal Na+ concentration, despite the almost 4-fold differencein the concentration of external NaCl. The intracellular glycerolconcentration alone accounts for 65% and 54%, respectively,of the osmotic balance in low and high salt grown cells. Key words: Dunaliella, cell volume, intracellular solutes 相似文献