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1.
Gilles Guerrier 《Physiologia plantarum》1996,97(3):583-591
NaCl (140 m M ) was applied to 14-day-old plants of salt-sensitive Lycopersicon esculentum Mill. cv. Volgogradskij and its wild relative L. pimpinellifolium Mill. accession PE-2. Changes in the relative growth rate of whole plant, and in the levels of inorganic and organic solutes in leaves, stems and roots were followed for 15 days after the application. Short-term salt exposure (4–6 days of salinization) resulted in enhanced relative growth rates for L. pimpinellifolium , but did not affect growth of L. esculentum , After 6 days of salinization, the relative growth rates of both species decreased significantly; leading to practically comparable growth rates for them by day 15. In all parts of both species, the contribution of organic solutes to the osmotic potential (Ψs ) gradually decreased from 30% on day 0 to a value lower than 5% on day 4. In L. pimpinellifolium , compared to L. esculentum , short-term salt exposure resulted in (1) a higher percentage of adjustment of Ψs ; and (2) increases in Na+ and K+ uptake rates, and in the levels of organic acids and proline (the level of which reached that of sugars, i.e., 10 μmol g-1 dry weight. Conversely, in L. esculentum , drastic reductions of K+ uptake rates and organic acid levels occurred already on day 1. During long-term salt exposure, both species were able to adjust osmotically and both exhibited decreases in organic acid levels as well as in K+ uptake and accumulation rates in all parts. The results are discussed in an attempt to explain the adaptive responses during short-term salt exposure and the metabolic dysfunctions that lead to growth decrease after long-term exposure to salt. 相似文献
2.
The growth of the wild tomato species Lycopersicon peruvianum (L.) Mill, and L. pennellii (Correll) D'Arcy, was compared with that of the cultivated tomato, L. esculentum Mill. cv. VE 234, under conditions of reduced K+ supply. Growth was impaired less in the wild than in the cultivated species. The higher efficiency of K+ utilization in the wild species was not associated with more efficient JC uptake from the medium. The rate of K+ uptake by whole plants was similar in the three species, but the rate of uptake by detached root tips was lower in the wild species. The permeability of the plasma membrane to K+ was apparently similar in root tips of the three species, but the tonoplast permeability was much lower in the wild than in the cultivated species. 相似文献
3.
Two tomato ( Lycopersicon esculentum Mill. cv. Pera) callus lines tolerant to NaCl were obtained by successive subcultures of NaCl-sensitive calli in 50 and 100 m M NaCl-supplemented medium. Growth and ion content, as well as plasma membrane lipid composition, fluidity and H+ -ATPase (EC 3.6.1.35) activity, were studied in both NaCl-sensitive and NaCl-tolerant calli. Although calli tolerant to 100 m M NaCl exhibited a reduced growth relative to calli sensitive to NaCl or tolerant to 50 m M NaCl, growth of calli tolerant to 100 m M NaCl was higher than that of NaCl-sensitive calli grown for one subculture in 100 m M NaCl. Growth in the presence of 100 m M NaCl provoked an increase of Na+ and Cl− content, but no significant changes in K+ and Ca2+ . As compared with NaCl-sensitive and 50 m M NaCl-tolerant calli, plasma membrane vesicles isolated from calli tolerant to 100 m M NaCl exhibited a higher phospholipid and sterol content as well as a lower phospholipid/free sterol ratio and a lower double bond index (DBI) of phospholipid fatty acids. The changes in plasma membrane lipid composition were correlated with a decrease of plasma membrane fluidity in calli tolerant to 100 m M NaCl, as indicated by fluorimetric studies using diphenylhexatriene (DPH) as probe. Plasma membrane-enriched vesicles isolated from calli tolerant to 100 m M NaCl showed lower ATP hydrolysis and ATP-dependent H+ -pumping activities, as well as a lower passive permeability to H+ than plasma membrane from NaCl-sensitive and 50 m M NaCl-tolerant calli. The involvement of the changes in plasma membrane lipid content and composition, fluidity and H+ -ATPase activity in salt tolerance of tomato calli is discussed. 相似文献
4.
5.
J. J. Alarcón M. J. Sánchez-Blanco M. C. Bolarín A. Torrecillas 《Physiologia plantarum》1993,89(3):441-447
Cultivated tomato Lycopersicon esculentum (L.) Mill. cv. P-73 and its wild salt-tolerant relative L. pennellii (Correll) D'Arcy accession PE-47 growing on silica sand in a growth chamber were exposed to 0, 70, 140 and 210 m M NaCl nutrient solutions 35 days after sowing. The saline treatments were imposed for 4 days, after which the plants were rinsed with distilled water. Salinity in L. esculentum reduced leaf area and leaf and shoot dry weights. The reductions were more pronounced when sodium chloride was removed from the root medium. Reduction in leaf area and weight in L. pennellii was only observed after the recovery period. In both genotypes salinity induced a progressive reduction in leaf water potential and leaf conductance. During the recovery period leaf water potential (ψ1 ) and leaf conductance (g1 ) reached levels similar to those of control plants in wild and cultivated species, respectively. Leaf osmotic potential at full turgor (ψos ) decreased in the salt treated plants of both genotypes, whereas the bulk modulus of elasticity was not affected by salinity. Leaf water potential at turgor loss point (ψtlp ) and relative water content at turgor loss point (RWCtlp ) appeared to be controlled by leaf osmotic potential at full turgor (ψos ) and by bulk modulus of elasticity, respectively. At lowest salinity, the wild species carried out the osmotic adjustment based almost exclusively on Cl− and Na+ , with a marked energy savings. Under highest salinity, this species accommodate the stress through a higher expenditure of energy due to the contribution of organic solutes to the osmotic adjustment. The domesticated species carried out the osmotic adjustment based always on an important contribution of organic solutes. 相似文献
6.
The responses to NaCl of cultured leaf discs and leaflets derived from fully differentiated leaves and of shoot apices excised from the cultivated tomato Lycopersicon esculentum Mill. and its wild salt-tolerant relatives L. peruvianum (L.) Mill, and Solanum pennellii Cor were compared. The results suggest that the tolerance of the whole plant to salt depends largely on the tolerance of plant organs containing meristematic tissues rather than on tissues already differentiated. This suggestion is based on the positive correlation found between the response to NaCl of shoot apices and of the whole plant, i.e. both whole plants and apices of the wild species were more resistant to salt than those of the cultivated species. No difference was found among the species with respect to the responses of the fully differentiated parts. The ion balance (K+ /Na+ and Cl− /Na+ ) in detached leaves and apices exposed to salt was different from the balance in the same parts while attached to the salt-treated plant. This difference may be due to the severance of the excised parts from the major sites controlling the balance of ions in the whole plant. 相似文献
7.
Tesshu Tamai Miwako Inoue Toshio Sugimoto Kuni Sueyoshi Naomasa Shiraishi & Yoshikiyo Oji 《Physiologia plantarum》1999,106(3):296-301
We investigated the cause and effect relationships among ethylene, polyamines, and K+ in barley ( Hordeum vulgare L. cv. Amagi) seedlings. Application of 1-aminocyclopropane-1-carboxylic acid (ACC), a precursor of ethylene, to the growth medium caused a decrease in K+ concentration in roots and an increase in shoots. Addition of ACC induced putrescine accumulation in roots, while spermidine and spermine levels remained unchanged. Exogenous supply of putrescine led to putrescine accumulation and reduced K+ concentration. Application of Co2+ , an inhibitor of ethylene biosynthesis, together with ACC, inhibited putrescine accumulation with a decrease in K+ concentration in roots. ACC-treated roots showed K+ uptake capacity equivalent to that of control roots, implying that the majority of K+ is translocated to shoots. These results suggest that ethylene regulates K+ partitioning between roots and shoots through the level of accumulation of putrescine in barley seedlings. 相似文献
8.
The influence of plant ontogeny on xylem exudate K+ concentrations and K+ transport to the shoot was studied in both nutrient-solution and field-grown tomato plants ( Lycopersicon esculentum ).
K+ concentrations in xylem exudate from decapitated plants decreased during tomato plant development from a high of 12 m M to a low of 5 m M . In the nutrient-solution plants, the most rapid decline occurred during the vegetative growth phase, while in field-grown plants, the xylem K+ concentrations remained high during an-thesis and then subsequently declined. The rapid decline in nutrient-solution plants might be related to a decrease in the absorptive efficiency of the root system. In field-grown plants, a reduction in the availability of assimilates to the root might account in part for the decrease in xylem exudate K+ concentrations. The volume (ml h−1 plant−1 ) and the net rates of K+ exudation (mmol h−1 plant−1 ) decreased dramatically as the fruits approached maturity. Since only a small reduction in xylem exudate K+ concentrations occurred during fruiting, the hydraulic conductivity of the root system decreased as the tomato plants aged. It is proposed that the ontogenetic changes in xylem transport of K+ contribute to a reduction in leaf free space K+ concentration which would explain the decline in tomato leaf K+ concentrations. 相似文献
K
9.
Influence of exogenously supplied potassium and sodium salts on the abscisic acid-induced proline accumulation in barley leaf segments 总被引:1,自引:0,他引:1
A stimulation of the abscisic acid (ABA)-induced increase in proline was observed in leaf segments of barley ( Hordeum vulgare L. cv. Georgie) if K+ or Na+ were supplied in the external medium as salts of monovalent anions such as NO3 , Br, Cr and I, but not when sulphate or phosphate were used. To a lesser extent, the effect was evident also with RbCl, but it did not occur when chlorides of Li+ . Cs+ , NH4 + , Mg:+ and Ca2+ were used. Both KC1 and NaCl in the concentration range 2–100 m M influence the ABA-dependent proline accumulation to the same extent; the increase induced was about 100% at 10 m M , and reached a maximum between 60 and 100 m M. The effect is not due to the osmotic activity of the salts and does not seem to depend on changes in K+ and Na+ levels within the leaf tissue, but it is somehow linked to their external concentration. The existence of a specific interaction between ABA and K+ or Na+ , possibly at the cell membrane level, is proposed. 相似文献
10.
Walter E. Riedell 《Physiologia plantarum》1987,69(2):299-304
When 1 m M spermidine or spermine was included in an absorption solution which contained 20 m M Na+ and 1 m M Rb+ , Na+ influx into excised maize roots ( Zea mays L. cv. Golden Cross Bantam) was reduced. Rb+ influx was reduced in the presence of spermidine and uneffected in the presence of spermine when compared with control solutions. When 1 m M Ca2+ replaced the polyamines, Na+ influx was strongly reduced and Rb+ influx was promoted. Rb+ influx from 1 m M Rb+ solutions which did not contain Na+ was also promoted by 1 m M Ca2+ , but was inhibited by 1 m M spermidine. This Ca2+ promotion of Rb+ influx could be reversed by 10 times greater concentration of spermidine in the absorption solution. H+ efflux from excised roots was inhibited by spermidine when compared with Ca2+ or control solutions, however, the plasma membrane ATPase was not inhibited by spermidine. It is concluded that external Ca2+ plays two separate roles in membrane function, only one of which can be substituted for by polyamines. The first role, maintenance of membrane integrity, can be substituted for by spermidine or spermine. The second function, maintenance of the Rb+ transport mechanism, is Ca2+ specific and cannot be substituted for by spermidine or spermine. The results of this study are discussed in terms of electrostatic interactions between the plasma membrane and the Ca2+ or polyamines. 相似文献
11.
Apoplastic pH and inorganic ion levels in tomato fruit: A potential means for regulation of cell wall metabolism during ripening 总被引:6,自引:1,他引:5
Apoplastic pH and ionic conditions exert strong influence on cell wall metabolism of many plant tissues; however, the nature of the apoplastic environment of ripening fruit has been the subject of relatively few studies. In this report, a pressure-bomb technique was used to extract apoplastic fluid from tomato fruit ( Lycopersicon esculentum Mill.) pericarp at several developmental stages. pH and the levels of K+ , Na+ , Ca2+ , Mg2+ , Cl− and P were determined and compared with the values for the bulk pericarp and locule tissues. The pH of the apoplastic fluid from pericarp tissue decreased from 6.7 in immature and mature-green fruits to 4.4 in fully-ripe fruit. During the same period, the K+ concentration increased from 13 to 37 m M . The levels of Na+ and divalent cations did not change, whereas the anions P and Cl− increased in ripe fruit. Ca2+ levels remained relatively constant during ripening at 4–5 m M , concentrations that effectively limit pectin solubilization. The electrical conductivity of the apoplastic liquid increased 3-fold during ripening, whereas osmotically active solutes increased 2-fold. Pressure-treated fruit retained the capacity to ripen. The decline in apoplastic pH and increase in ionic strength during tomato fruit ripening may regulate the activity of cell wall hydrolases. The potential role of apoplastic changes in fruit ripening and softening is discussed. 相似文献
12.
Salinity tolerance of Kosteletzkya virginica. II. Root growth, lipid content, ion and water relations 总被引:1,自引:0,他引:1
Abstract. Kosteletzkya virginica (L.) Presl., a dicot halophyte native to brackish tidal marshes, was grown on nutrient solution containing 0. 85, 170 or 255 mol m 3 NaCl, and the effects of external salinity on root growth, ion and water levels, and lipid content were examined in successive harvests. Root growth paralleled shoot growth trends, with some enhancement observed at 85 mol m 3 NaCl and a reduction noted at the higher salinities. Root Na+ content increased with increasing external NaCl, but remained constant with time for each treatment. K+ content, although lower in salt-grown plants after 14 d salinization, subsequently increased to levels comparable to unsalinized plants. A strong K+ affinity was reflected in the increased K+ /Na+ selectivity of salt-grown plants and by their low Na+ /K+ ratios. Cl levels rose in salinized plants and values were double or more those for Na+ , indicating the possibility of a sodium-excluding mechanism in roots. Root phospholipids and sterols, principal membrane constituents, were maintained or elevated and the free sterol/phospholipids ratio increased in salinized K. virginica plants, suggesting retention of overall membrane structure and decreased permeability. This response, considered in light of root calcium maintenance and high potassium levels, suggests that salinity-induced changes in membrane lipid composition may be important in preventing K+ leakage from cells. 相似文献
13.
Effects of salinity and replacement of K+ by Na+ on lipid composition in two sugar beet inbred lines
The effects of NaCl and replacement of K+ by Na+ on the lipid composition of the two sugar beet inbred lines FIA and ADA were studied (a) with increasing additions of NaCl to the basal medium, and (b) with increasing replacement of K+ by Na+ at the same total concentration as in the basal medium. Direct relations were noted between NaCl concentration of the nutrient solution and the phospholipid concentration in the roots of FIA, the genotype characterized by a low K+ /Na+ ratio, as well as between NaCl in the medium and the phospholipid concentration in the shoots of ADA, the genotype with a high K + /Na + ratio. The sulfolipid level in the roots of FIA was maintained at higher NaCl concentrations, while it was decreased in ADA. The glycolipid concentration in the shoots of ADA and the degree of unsaturation of the fatty acids of the total lipid fraction were decreased by salinity, indicating reduced biosynthesis of chloroplast glycolipids and/or accelerated oxidation of these lipids in the presence of NaCl.
In the Na+ for K+ replacement experiment a low content of K+ in the medium resulted in decreased levels of total lipids, phospholipids and sulfolipid in the roots of both genotypes, which did not relate to root growth. K+ -leakage from the roots at low K+ -level in the medium may be reduced by the increase in saturation of the lipids. In the shoots of ADA increased levels of total lipids, phospholipids and Sulfolipid were noted at a low K+ -concentration of the nutrient solution. 相似文献
In the Na
14.
Salt tolerance of the reed plant Phragmites communis 总被引:6,自引:0,他引:6
Reed plants ( Phragmites communis Trinius) were grown at NaCl concentrations up to 500 m M and their growth, mineral contents and leaf blade osmotic potential were determined. Addition of NaCl up to 300 m M did not affect growth significantly. Sucrose, Cl- and Na+ concentrations in the shoots increased with the salinity of the medium and the shoot water content decreased. K+ always contributed most to the leaf osmotic potential. Even in the presence of 250 m M NaCl in the rooting medium, the leaf blade contained only 50 mM Na+ , suggesting that the plants have an efficient mechanism for Na+ exclusion. 22 Na+ uptake experiments suggested that the retranslo-cation of absorbed Na+ from shoots to the rooting medium lowered the uptake of Na+ . 相似文献
15.
CHUN-MEI WANG JIN-LIN ZHANG XUE-SONG LIU ZHAN LI GUO-QIANG WU JIAN-YI CAI TIMOTHY J. FLOWERS & SUO-MIN WANG 《Plant, cell & environment》2009,32(5):486-496
Puccinellia tenuiflora is a useful monocotyledonous halophyte that might be used for improving salt tolerance of cereals. This current work has shown that P. tenuiflora has stronger selectivity for K+ over Na+ allowing it to maintain significantly lower tissue Na+ and higher K+ concentration than that of wheat under short- or long-term NaCl treatments. To assess the relative contribution of Na+ efflux and influx to net Na+ accumulation, unidirectional 22 Na+ fluxes in roots were carried out. It was firstly found that unidirectional 22 Na+ influx into root of P. tenuiflora was significantly lower (by 31–37%) than in wheat under 100 and 150 m m NaCl. P. tenuiflora had lower unidirectional Na+ efflux than wheat; the ratio of efflux to influx was similar between the two species. Leaf secretion of P. tenuiflora was also estimated, and found the loss of Na+ content from leaves to account for only 0.0006% of the whole plant Na+ content over 33 d of NaCl treatments. Therefore, it is proposed that neither unidirectional Na+ efflux of roots nor salt secretion by leaves, but restricting unidirectional Na+ influx into roots with a strong selectivity for K+ over Na+ seems likely to contribute to the salt tolerance of P. tenuiflora . 相似文献
16.
The tolerances of Columbia Arabidopsis thaliana (L.) Heynh. to NaCl, L-asparagine (L-Asn) and D-asparagine (D-Asn) during seedling establishment on sterile agar medium were determined. Germination and the establishment of upright seedlings with expanded green cotyledons were increasingly inhibited by NaCl concentrations from 20 to 180 m M and radicle growth was prevented at 225 m M NaCl. Tolerance of established seedlings to NaCl was similar at these concentrations. Seedling establishment was prevented at 20 m M L-Asn and 60 m M D-Asn, but L-Asn was not toxic to established seedlings. At lower concentrations, exogenous L- and D-Asn enhanced NaCl tolerance during germination and seedling establishment. Inhibition of seedling establishment by NaCl concentrations below 225 m M was reduced by the addition of L- and D-Asn to the medium. Maximal reduction of NaCl inhibition occurred between 2 and 4 m M for both L- and D-Asn. Higher concentrations of NaCl prevented establishment whether exogenous Asn was present or not. Reduction of NaCl inhibition occurred to the same extent whether L-Asn was presented simultaneously with the NaCl or preloaded for up to 24 h. The total seedling content of Na+ increased about 4-fold to 55 μg (mg dry weight)−1 as the medium concentration of NaCl was increased from 9 μ M to 150 m M NaCl. Total K+ content declined about 80% from about 34 μg (mg dry weight)−1 over the same range of NaCl concentrations. The Na+ uptake and K+ efflux by whole seedlings were similar whether or not NaCl tolerance was increased by exogenous Asn. 相似文献
17.
Low-K+ , high-Na+ cells of strain RL21a of Neurospora crassa , in steady state with 25 m M Na+ , were used to study K+ /Na+ exchanges in the presence or absence of Ca2+ and Mg2+ . In the presence of Ca2+ and Mg2+ , a low concentration of K+ (0.3 m M ) triggered a rapid exchange, but in the absence of the divalents, a high K+ concentration (30 m M ) was required to initiate the exchange at a rapid rate. In the absence of Ca2+ and Mg2+ , K+ uptake did not occur at low K+ concentration, internal K+ did not regulate Na+ influx in the presence of external K+ , and the efflux of Na+ proceeded at maximum activity at very low-K+ contents. 相似文献
18.
A tomato ( Lycopersicon esculentum Mill. cv. Pera) callus culture tolerant to NaCl was obtained by successive subcultures of NaCl-sensitive calli in medium supplemented with 50 m M NaCl. NaCl-tolerant calli grew better than NaCl-sensitive calli in media supplemented with 50 and 100 m M NaCl. Analysis of callus ion content showed a strong increase in Na+ and Cl− both in NaCl-tolerant and -sensitive calli grown in media containing NaCl for one subculture. Cells from NaCl-tolerant calli showed a higher H+ extrusion activity than those from NaCl-sensitive calli grown for one subculture in the presence of NaCl. The inhibition of H+ extrusion by NaCl-sensitive cells was correlated with an inhibition of microsomal vanadate-sensitive H+ -ATPase (EC 3.6.1.35) and ATP-dependent H+ transport, while the stimulation of H+ extrusion by cells tolerant to 50 m M NaCl was correlated with an increase in plasma membrane ATP-dependent H+ transport. The increase of ATP-dependent H+ extrusion in plasma membranes isolated from 50 m M NaCl-tolerant calli was not a result of stimulation of a vanadate-sensitive ATP hydrolytic activity or an increase in passive permeability to H+ . Relative to NaCl-sensitive calli, plasma membrane H+ -ATPase from calli tolerant to 50 m M NaCl showed a lower Km for Mg2+ -ATP. Our results indicate that tolerance of tomato calli to 50 m M NaCl increases the affinity of plasma membrane H+ -ATPase for the substrate ATP and stimulates the H+ -pumping activity of this enzyme without modifying its phosphohydrolytic activity. 相似文献
19.
M. J. Sánchez-Blanco M. C. Bolarín J. J. Alarcón A. Torrecillas 《Physiologia plantarum》1991,83(2):269-274
Cultivated tomato Lycopersicon esculentum (L.) Mill. cv. P-73 and its wild salt tolerant relative L. pennellii (Correll) D'Arcy accession PE-47, were grown during spring-summer 1989 under unheated plastic greenhouse conditions. Plants were submitted to two different salt treatments using 0 and 140 mM NaCI irrigation water. In both tomato species, salinity caused a proportionally larger reduction in leaf area than in leaf weight and, in L. esculentum , a proportionally larger decrease in stem weight than in leaf weight. Daily variations in leaf water potential (Ψ1 ) were fundamentally due to changes in the evaporative demand of the atmosphere. Reductions in Ψ1 due to salinity were consistent only in L. esculentum . In all the conditions studied, leaf turgor was maintained. Leaf conductance (g1 )was higher in L. esculentum than in L. pennellii .Salinity induced a clear reduction in g1 levels in L. esculentum whereas, in L. pennellii , this reduction was noted only in May. In both species the Ψo s (leaf osmotic potential at full turgor) levels were reduced by salinity. The bulk modulus of elasticity (E) and relative water content at turgor loss point (RWCtlp ) were not affected by salinity. The RWCtlp values in L. pennellii seem to be controlled by E values. 相似文献
20.
Developmental changes in tomato fruit composition in response to water deficit and salinity 总被引:6,自引:0,他引:6
Processing tomato ( Lycopersicon esculentum Mill. cv. UC82B) plants were subjected to moderate levels of water deficit and salinity (Na2 SO4 /CaCl2 ) in sand culture. Fruit water content and the relative contributions of organic and inorganic constituents to fruit solute potential (Ψ ) and soluble solids content were determined throughout development. Fruit Ψ averaged –0.63, –0.86 and –0.77 MPa in the control, salinity and water deficit plants, respectively. Reduced net water import and maintenance of solute accumulation, irrespective of water import, accounted for the reductions in Ψ of stressed fruits. Mineral ions (Na+ , K+ , Ca2+ , Mg2+ , Cl− and SO2- 4 ) contributed –0.31 MPa to Ψ in salinized fruit, compared with –0.19 MPa in control and water deficit treatments. Changes in net carbon accumulation were not observed among treatments, despite considerable differences in fruit K+ status. Starch accumulation in immature fruit was increased and hexose accumulation was decreased by both salinity and water deficit. Maximum starch levels were negatively correlated with total fruit Ψ , but were independent of fruit K+ . Organic acid levels were generally higher throughout development in salinized plants, relative to control plants, and correlated with increased inorganic cation rather than anion accumulation in these fruits. 相似文献