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1.
Imène Ben Salah Tarek Slatni Alfonso Albacete Mhemmed Gandour Cristina Martínez Andújar Hayet Houmani Karim Ben Hamed Vicente Martinez Francisco Pérez-Alfocea Chedly Abdelly 《Symbiosis (Philadelphia, Pa.)》2010,51(2):187-195
In this study, the effect of 100 mM NaCl on physiological and biochemical responses were investigated in nodules of two Medicago ciliaris lines differing in salt tolerance (TNC 1.8 and TNC 11.9). Results showed that, on the basis of growth and nitrogen fixation,
the line TNC 1.8 proved more salt tolerant than TNC 11.9. The salt-induced oxidative stress (membrane lipid peroxidation,
leghemoglobin degradation, antioxidant activities reduction) occurred similarly in nodules of both lines. The tolerant line
TNC 1.8 showed a better capacity to preserve higher sucrolytic activities and maintained higher nodule malate concentration,
although total organic acids decreased in both lines. The higher amount of organic acids in the tolerant line seems to be
related to its capacity to maintain higher NH4 nodule concentration in comparison with the sensitive line. Although salt stress reduced concentrations of the majority of
amino acid in both lines, the decrease of the most preponderant amino acids glycine, valine, aspartate and glutamate was more
accentuated in the sensitive line TNC 11.9. However, alanine concentration increased in the nodules of this sensitive line,
suggesting a higher incidence of stress-induced hypoxia. The present study provides further evidence that salt tolerance of
nitrogen fixation in the tolerant line is linked to a more effective supply of malate to bacteroids which allows the synthesis
of amino acids required to maintain both plant and nodule growth. 相似文献
2.
Response of nitrogen fixation in relation to nodule carbohydrate metabolism in Medicago ciliaris lines subjected to salt stress 总被引:1,自引:0,他引:1
Ben Salah I Albacete A Martínez Andújar C Haouala R Labidi N Zribi F Martinez V Pérez-Alfocea F Abdelly C 《Journal of plant physiology》2009,166(5):477-488
The effect of salt stress on nitrogen fixation, in relation to sucrose transport towards nodules and other sink organs and the potential of sucrose breakdown by nodules, was investigated in two lines of Medicago ciliaris. Under salt stress conditions, the two lines showed a decrease of total biomass production, but TNC 1.8 was less affected by salt than TNC 11.9. The chlorophyll content was not changed in TNC 1.8, in contrast to TNC 11.9. Shoot, root, and nodule biomass were also affected in the two lines, but TNC 1.8 exhibited the higher potentialities of biomass production of these organs. Nitrogen fixation also decreased in the two lines, and was more sensitive to salt than growth parameters. TNC 1.8 consistently exhibited the higher values of nitrogen fixation. Unlike nodules, leaves of both lines were well supplied in nutrients with some exceptions. Specifically, the calcium content decreased in the sensitive line leaves, and the nodule magnesium content was not changed in either line. The tolerant line accumulated more sodium in its leaves. The two lines did not show any differences in the nodule sodium content. Sucrose allocation towards nodules was affected by salt in the two lines, but this constraint did not seem to affect the repartition of sucrose between sink organs. Salt stress induced perturbations in nodule sucrolytic activities in the two lines. It inhibited sucrose synthase, but the inhibition was more marked in TNC 11.9; alkaline/neutral activity was not altered in TNC 1.8, whereas it decreased more than half in TNC 11.9. Thus, the relative tolerance of TNC 1.8 to salt stress could be attributed to a better use of these photoassimilates by nodules and a better supply of bacteroids in malate. The hypothesis of a competition for sucrose between nodules and other sink organs under salt stress could not be verified. 相似文献
3.
This study compared the growth, nodulation, N2 fixation, and ion distribution in three Medicago truncatula lines, in response to salt in nutrient solution. Two local lines (TN8.20 and TN6.18) and a reference line (Jemalong 6) were inoculated with a reference strain Sinorhizobium meliloti 2011, a very tolerant strain to salinity (700 mM NaCl) and grown in a controlled glasshouse with or without 75 mM NaCl. A genotypic variation in tolerance to salt was found: TN6.18 was the most sensitive line whereas TN8.20 was the most tolerant. The relative tolerance of TN8.20 was concomitant with the lowest leaf Na+ concentration and the highest nodule biomass production. However, nodule efficiency (amount of nitrogen fixed per g dry weight nodule) decreased in all lines. Results suggest that the tolerance to salt seems to depend on the host plant ability to protect its leaves against an excessive Na+ (and Cl?) accumulation, and its ability to maintain the development of an abundant nodular system, which in turn determines an important rate of nitrogen fixation and allows the plants to conserve their growth potentialities. The loss of the nodular efficiency under salt stress seems to be compensated by a large nodule biomass. 相似文献
4.
For plant salt tolerance, it is important to regulate the uptake and accumulation of Na+ ions. The yeast pmp3 mutant which lacks PMP3 gene accumulates excess Na+ ions in the cell and shows increased Na+ sensitivity. Although the function of PMP3 is not fully understood, it is proposed that PMP3 contributes to the restriction
of Na+ uptake and consequently salt tolerance in yeasts. In this paper, we have investigated whether the lack of RCI2A gene, homologous to PMP3 gene, causes a salt sensitive phenotype in Arabidopsis (Arabidopsis thaliana (L.) Heynh.) plants; and to thereby indicate the physiological role of RCI2A in higher plants. Two T-DNA insertional mutants
of RCI2A were identified. Although the growth of rci2a mutants was comparable with that of wild type under normal conditions, high NaCl treatment caused increased accumulation
of Na+ and more reduction of the growth of roots and shoots of rci2a mutants than that of wild type. Undifferentiated callus cultures regenerated from rci2a mutants also accumulated more Na+ than that from wild type under high NaCl treatment. Furthermore, when wild-type and rci2a plants were treated with NaCl, NaNO3, Na2SO4, KCl, KNO3, K2SO4 or LiCl, the rci2a mutants showed more reduction of shoot growth than wild type. Under treatments of tetramethylammonium chloride, CaCl2, MgCl2, mannitol or sorbitol, the growth reduction was comparable between wild-type and rci2a plants. These results suggested that RCI2A plays a role directly or indirectly for avoiding over-accumulation of excess Na+ and K+ ions in plants, and contributes to salt tolerance. 相似文献
5.
Mariana A. Reginato Guillermina I. Abdala Otto Miersch Oscar A. Ruiz Elsa Moschetti Virginia Luna 《Biologia》2012,67(4):689-697
Prosopis strombulifera, a common legume in high-salinity soils of Argentina, is a useful model for elucidation of salt tolerance mechanisms and
specific biochemical pathways in halophytes, since its NaCl tolerance exceeds the limit described for most halophytic plants.
We analyzed the effects of the increasing concentration of two main soil salts, Na2SO4 and NaCl, on growth parameters of P. strombulifera, chlorophyll levels, and content of jasmonates (JAs) and polyamines (PAs), which are key molecules involved in stress responses.
P. strombulifera showed a halophytic response (growth promotion) to NaCl, but strong growth inhibition by iso-osmotic solutions of Na2SO4. Chlorophyll levels, number of leaves and leaf area were also differentially affected. An important finding was the partial
alleviation of SO42− toxicity by treatment with two-salt mixture. JAs are not directly involved in salt tolerance in this species since its levels
decrease under all salt treatments. Beneficial effects of Putrescine (Put) accumulation in NaCl treated plants maybe inferred
probably associated with the antioxidative defense system. Another novel finding is the accumulation of the uncommon PA cadaverine
in roots under high Na2SO4, which may be related to SO42− toxicity. 相似文献
6.
Abdelhamid Khaldi Rebai Ben Ammar Su Young Woo Noureddine Akrimi Ezzeddine Zid 《Acta Physiologiae Plantarum》2011,33(3):765-775
The salinity tolerance and ion transport of 2-month-old seedlings of stone pine (Pinus pinea L.) grown in hydroponic solution containing various concentrations of NaCl (0–100 mM) were studied. The presence of salt
of up to 100 mM did not significantly reduce growth. Seedling hydration was insensitive to salinity. High salt concentrations
reduced K+ and Ca2+ uptake, root accumulation, and export to shoots. Na+ and Cl− ions, representing the major part of the ionic uptake, were effectively compartmentalized in vacuoles. We concluded that
seedlings of stone pine cultivated hydroponically were highly tolerant to salt concentrations of up to 100 mM for a culture
period of 38 days. This tolerance was associated with the accumulation of Na+ and Cl− ions in the shoots. 相似文献
7.
Adnane Bargaz Cherki Ghoulam Mustapha Faghire Hesham Aslan Attar Jean-Jacques Drevon 《Symbiosis (Philadelphia, Pa.)》2011,53(3):157-164
Although recent studies have addressed the effects of phosphorus (P) deficiency on nodule O2 permeability, little attention has been given to the relationship between nodule P status and nodule permeability. To study
these traits, four recombinant inbred lines, namely RILs 34, 83, 115, 147 and one local variety (Concesa) of common bean (Phaseolus vulgaris) were inoculated with RhM11 (a native rhizobial strain from Haouz area of Marrakesh), and grown in hydroaeroponic culture
under P-sufficiency (250 μmol P plant−1 week−1) versus P-deficiency (75 μmol P plant−1 week−1) conditions. At the flowering stage, the biomass of plants and nodules and their P contents was determined after measuring
O2 uptake by nodulated roots (Conr) and nodule conductance to O2 diffusion (gn). The results showed that P-deficiency significantly decreased plant growth and nodulation, though there were differences
between bean genotypes. P-deficiency also induced a decrease in nodule P content (31%) in both sensitive (83, 147) and tolerant
lines (34, 115), a 42 and 27% reduction in shoots of sensitive and tolerant lines, respectively. These decreases were associated
with significant variations in nodule surface and O2 permeability among bean genotypes and P-nutrition. Under P-deficiency, gn increased more for the sensitive (39%) than for the tolerant lines (27%). This increase was linked with a rise both in the
P levels in nodules and shoots, as well as in the efficiency of symbiotic nitrogen fixation as determined by nodule-dependent
biomass production for the sensitive lines. Furthermore, positive correlations were found between O2 permeability, gn and P content both in nodules and shoots (r
2 = 0.94** and r
2 = 0.96**). We conclude that nodule variations in Conr and gn are related to nodule P content, and may contribute to the adaptation of energy metabolism in N2-fixing bean nodules to P-deficiency. 相似文献
8.
The lignocellulosic crop Miscanthus spp. has been identified as a good candidate for biomass production. The
responses of Miscanthus sinensis Anderss. to salinity were studied to satisfy the needs for high yields in marginal
areas and to avoid competition with food production. The results indicated that the relative advantages of the
tolerant accession over the sensitive one under saline conditions were associated with restricted Na+ accumulation
in shoots. Seedlings of two accessions (salt-tolerant ‘JM0119’ and salt-sensitive ‘JM0099’) were subjected to 0
(control), 100, 200, and 300 mM NaCl stress to better understand the salt-induced biochemical responses of genes
involved in Na+ accumulation in M. sinensis. The adaptation responses of genes encoding for Na+
/H+ antiporters,
NHX1 and SOS1 to NaCl stress were examined in JM0119 and JM0099.The cDNA sequences of genes examined
were highly conserved among the relatives of M. sinensis based on the sequencing on approximate 600 bp-long
cDNA fragments obtained from degenerate PCR. These salt-induced variations of gene expression investigated by
quantitative real-time PCR provided evidences for insights of the molecular mechanisms of salt tolerance in
M. sinensis. The expression of NHX1 was up-regulated by salt stress in JM0119 shoot and root tissues. However,
it was hardly affected in JM0099 shoot tissue except for a significant increase at the 100 mM salt treatment, and it
was salt-suppressed in the JM0099 root tissue. In the root tissue, the expression of SOS1 was induced by the high
salt treatment in JM0119 but repressed by all salt treatments in JM0099. Thus, the remarkably higher expression
of NHX1 and SOS1 were associated with the resistance to Na+ toxicity by regulation of the Na+ influx, efflux, and
sequestration under different salt conditions. 相似文献
9.
According to sequences of several vacuolar Na+/H+ antiporter genes from Xinjiang halophytic plants, a new vacuolar Na+/H+ antiporter gene (HcNHX1) from the halophyte Halostachys caspica was obtained by RACE and RT-PCR using primers corresponding to conserved regions of the coding sequences. The obtained HcNHX1 cDNA was 1,983 bp and contained a 1,656 bp open reading frame encoding a deduced protein of 551 amino acid residues. The
deduced amino acid sequence showed high identity with other NHX1 we have cloned previously from halophyte in Xinjiang desert
area. The phylogenetic analysis showed that HcNHX1 formed a clade with NHX homologs of Chenopodiaceae. Expression profiles
under salt treatment and ABA induction were investigated, and the results revealed that expression of HcNHX1 was induced by NaCl and ABA. To compare the degree of salt tolerance, we over-expressed HcNHX1 in Arabidopsis. Two transgenic lines grew more vigorously than the wild type (WT) under salt stress. The analysis of ion
contents indicated that under salt stress, the transgenic plants compartmentalized more Na+ in the leaves compared with wild-type plants. Together, these results suggest that the products of the novel gene HcNHX1 from halophyte Halostachys caspica is a functional tonoplast Na+/H+ antiporter. 相似文献
10.
Selected NaCl tolerant and unselected control lines ofHolcus lanatus L.,Lolium perenne L.,Dactylis glomerata L., andFestuca rubra L. were grown in sand culture at 0, 100, 200, 250, and/or 300 ml m-3NaCl for seven weeks. The tolerant lines of all four species produced significantly greater both shoot and root dry matter
at all NaCl treatments compared with the unselected control lines. Na+, K+, Cl-, Ca2+, and Mg2+ contents of leaf, stalk, and roots of each species were determined. The tolerant lines ofH. lanatus contained less Na+ and less Ca2+ but higher K+ in shoots, compared with the unselected line. By contrast theL. perenne tolerant line had higher Na+ and Cl- contents at 250, and 300 mol m-3 NaCl in shoots than the unselected line suggesting a halophytic nature of the tolerant line.D. glomerata accumulated greater quantities of ions compared with the other species examined. The tolerant line contained significantly
less Cl- but more K+ in its shoots than the unselected line. Na+, Cl-, and K+ contents in the shoots of the tolerant line ofF.rubra were higher than in the unselected line shoots. Therefore selection for NaCl tolerance may provide useful material for examining
the basis of tolerance. 相似文献
11.
T. V. Roslyakova O. V. Molchan A. V. Vasekina E. M. Lazareva A. I. Sokolik V. M. Yurin A. H. de Boer A. V. Babakov 《Russian Journal of Plant Physiology》2011,58(1):24-35
Two barley cultivars (Hordeum vulgare L., cvs. Elo and Belogorskii) differing in salt tolerance were used to study 22Na+ uptake, expression of three isoforms of the Na+/H+ antiporter HvNHX1-3, and the cellular localization of these isoforms in the elongation zone of seedling roots. During short
(1 h) incubation, seedling roots of both cultivars accumulated approximately equal quantities of 22Na+. However, after 24-h incubation the content of 22Na+ in roots of a salt-tolerant variety Elo was 40% lower than in roots of the susceptible variety Belogorskii. The content of
22Na+ accumulated in shoots of cv. Elo after 24-h incubation was 6.5 times lower than in shoots of cv. Belogorskii and it was 4
times lower after the salt stress treatment. The cytochemical examination revealed that three proteins HvNHX1-3 are co-localized
in the same cells of almost all root tissues; these proteins were present in the tonoplast and prevacuolar vesicles. Western
blot analysis of HvNHX1-3 has shown that the content of isoforms in vacuolar membranes increased in response to salt stress
in seedling roots and shoots of both cultivars, although the increase was more pronounced in the tolerant cultivar. The content
of HvNHX1 in the seedlings increased in parallel with the enhanced expression of HvNHX1, whereas the increase in HvNHX2 and HvNHX3 protein content was accompanied by only slight changes in expression of respective
genes. The results provide evidence that salt tolerance of barley depends on plant ability to restrict Na+ transport from the root to the shoot and relies on regulatory pathways of HvNHX1-3 expression in roots and shoots during
salt stress. 相似文献
12.
Imène Ben Salah Héla Mahmoudi Margaret Gruber Tarek Slatni Mondher Boulaaba Mhemmed Gandour Dorsaf Messedi Karim Ben Hamed Riadh Ksouri Abdelali Hannoufa Chedly Abdelly 《Biologia》2011,66(5):813-820
The objective of this study was to determine more indepth physiological and antioxidant responses in two Medicago ciliaris lines (a salt-tolerant line TNC 1.8 and a salt-sensitive line TNC 11.9) with contrasting responses to 100 mM NaCl. Under salt stress, both lines showed a decrease in total biomass and in the growth rate for roots, but TNC 1.8 was less affected by salt than TNC 11.9 in that it maintained leaf growth even in the presence of added salt. In both lines, salt stress mainly affected micronutrient status (Fe, Mn, Cu and Zn) rather than K nutrition, but the tolerant line TNC 1.8 accumulated more Na in leaves and less in roots compared with TNC 11.9. Salt stress decreased total soluble sugars (TSS) in all organs of the sensitive line TNC 11.9, whereas TSS was only reduced in roots of the tolerant line. The salt-induced drop in growth was linked to an increase in lipid peroxidation in roots of both lines and in leaves of the sensitive line. The salt-tolerant line TNC 1.8 was more efficient at managing salt-induced oxidative damage in leaves and to a lesser extent in roots than the salt-sensitive line TNC 11.9, by preserving higher phenolic compound and superoxide dismutase levels in both organs. 相似文献
13.
Abdel Hamid A. Khedr Mamdouh S. Serag Mamdouh M. Nemat-Alla Amina Z. Abo El-Naga Reham M. Nada W. Paul Quick Gaber M. Abogadallah 《Acta Physiologiae Plantarum》2011,33(5):1769-1784
In the present study, Na+ manipulating genes could contribute not only to ion homeostasis but also to growth stimulation with exposing the halophyte
Atriplex halimus L. to moderate NaCl concentration. The stimulation of growth was attributed to Na+ accumulation inside the vacuole leading to increase leaf cell size as well as accelerate leaf cell division. Increasing the
assimilatory surface could result in enhancing the photosynthetic rate. The reduction of A. halimus growth compared to optimum growth at 50 and 200 mM NaCl could be attributed to osmotic effect rather than the ionic one of
salt stress. The inhibition of photosynthesis seemed to be resulted from limitation of CO2 due to the osmotic effect on stomatal conductance rather than the activity loss of photosynthetic machinery. The depletion
of starch content along with the increase in sucrose content could imply that photosynthesis may be a limiting for A. halimus growth. The fast coordinate induction of Na+ manipulating genes could reveal that the tolerance of A. halimus to high concentrations evolved from its ability to regulate and control Na+ influx and efflux. V-H
+-PPase may play a vital role in A. halimus tolerance to osmotic and/or ionic stress due to its kinetics of induction. It seemed that H+-ATPase plays a pivotal role in A. halimus tolerance to stress due to the increase in its protein level was detected with all NaCl concentrations as well as with PEG
treatments. Both of these genes might be useful in improving stress tolerance in transgenic crops. 相似文献
14.
The effects of NaCl (0, 50, 100, 150 and 200 mM) on growth, water relations, glycinebetaine, free proline, ion contents, stomata number and size of Kochia prostrata (L.) Schard were determined. Shoot and root fresh and dry matter, root and shoot length, relative growth rate, net assimilation rate, relative water content, water use efficiency, soluble sugars and glycinebetaine contents were not changed at low NaCl concentrations, but they were significantly decreased at 200 mM NaCl. The K+, Mg2+ and Ca2+ contents, water potential, chlorophyll a+b and carotenoides contents, and stomata number and size were reduced already at low concentrations of NaCl. In contrast, the Na+, Cl– and proline contents increased several times with increasing NaCl concentration. Kochia prostrata is a salt tolerant species, the optimal growth of this plant occurred up to 150 mM NaCl. The mechanisms of salt tolerance in the plant may be balance among ion accumulation and production of glycinebetaine, proline, soluble sugars for maintenance of pressure potential. 相似文献
15.
16.
The present work has been performed to study the growth and metabolic activities of two maize cultivars (cv. 323 and cv. 324) which are shown to have different tolerances to salt stress and to determine the effects of inoculation with Azospirillum spp. Along with identifying the mechanisms of maize salt tolerance and the role of Azospirillum (growth promoting rhizobacteria) in elevating salinity stress conditions is examined Maize cv. 323 was the most sensitive to salinity, while cultivar 324 was the most resistant of the 12 maize cultivars tested. Cultivars differences were apparent with certain growth criteria as well as related metabolic activities. The lack of a negative response to increasing NaCl concentration for water content, dry matter yield and leaf area of cv. 324 up to a concentration of – 0.6 MPa indicated salt tolerance. While for cv. 323 there was a marked inhibitory effect of salinity on growth. In the tolerant cv. 324, soluble and total saccharides, soluble protein in shoots and total protein in roots increased with salinity stress. The sensitivity of cv. 323 however was associated with depletion in saccharides and proteins. Proline accumulation was higher and detected earlier at a lower salinity concentration in the salt sensitive cv. 323 comapred to the salt tolerant cv. 324. When salt stressed maize was inoculated with Azospirillum, proline concentration declined significantly. The present study showed, in general, that the concentration of most amino acid increased on exposure to NaCl as well as when inoculated with Azospirillum. The relatively high salt tolerance of cv. 324, compared with cv. 323 was associated with a significantly high K+/Na+ ratio. Azospirillum inoculation markedly altered the selectivity of Na+, K+ and Ca++ especially in the salt sensitive cultivar cv. 323. Azospirillum restricted Na+ uptake and enhanced the uptake of K+ and Ca++ in cv. 323. A sharp reduction in the activity of nitrate reductase and nitrogenase in shoots and roots of both cultivars was induced by salinity stress. This reduction in NR and NA activity was highly significant at all salinity concentrations. Azospirillum inoculation stimulated NR and nitrogenase activity in both shoots and roots of both cultivars. The differential effect of Azospirillum inoculation on maize cv. 323 and cv. 324 illustrates the different sensitivity of these two cultivars to stress, but still does not provide any clues as to the key events leading to this difference. 相似文献
17.
Three types of transgenic tobacco plants were acquired by separate transformation or co-transformation of a vacuolar Na+/H+ antiporter gene, SeNHX1, and a betaine synthesis gene, BADH. When exposed to 200 mM NaCl, the dual gene-transformed plants displayed greater accumulation of betaine and Na+ than their wild-type counterparts. Photosynthetic rate and photosystem II activity in the transgenic plants were less affected
by salt stress than wild-type plants. Transgenic plants exhibited a greater increase in osmotic pressure than wild-type plants
when exposed to NaCl. More importantly, the dual gene transformed plants accumulated higher biomass than either of the single
transgenic plants under salt stress. Taken together, these findings indicate that simultaneous transformation of BADH and SeNHX1 genes into tobacco plants can enable plants to accumulate betaine and Na+, thus conferring them more tolerance to salinity than either of the single gene transformed plants or wild-type tobacco plants.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
This study describes two phenotypes of Arabidopsis thaliana (ecotype Columbia) developed in vitro under salt stress (75 mM NaCl). The phenotypes 01 and 02 appeared visibly distinguishable by rosette morphology and competence
to produce flowers. Phenotype 01, sensible to salt stress, accumulated high quantities of Na+, showed a slight reduction in dry mass, and high protein and chlorophyll contents. Moreover, its anatomy exhibited some xeromorphic
traits. Phenotype 02, clearly salt tolerant, showed a morphology similar to control plants, displaying typical phyllotactic
rosette and flowering stalk production. Accumulation of Na+, protein and chlorophyll contents were close to control plants. Reversion experiments on NaCl free MS medium, showed a partially
recovered phenotype 01. A threshold salt stress concentration that permits the simultaneous development of two phenotypes,
was found. 相似文献
19.
Shah Safdar Hussain Tobita Satoshi Shono Mariko 《Plant Cell, Tissue and Organ Culture》2002,71(2):95-101
Cell lines of Oryza sativa L. (cv. Taipei-309) were adapted to 30 mM LiCl and 150 mM NaCl. Both adapted lines were considerably more tolerant than non adapted line when grown on 200, 250 and 300 mM NaCl and 30 mM LiCl stresses. The tolerance of LiCl-adapted line to NaCl (150 to 300 mM) and the tolerance of NaCl-adapted cells line to LiCl (30 mM) indicated that there was a cross-adaptation towards alkali metals (Na+ and Li+) not the Cl–. Na+ and K+ contents of all lines which increased with increasing medium salinity but to a different degree. The increase in Na+ and K+ content in NaCl-adapted and non-adapted lines were comparable, while LiCl-adapted line accumulated significantly lower Na+and higher K+ content. Proline content of all lines increased with the increase in NaCl-stress but the magnitude of increase was much higher in the LiCl-adapted than other lines. The differential response of adapted lines to NaCl stress in accumulating proline and maintaining the ionic contents reveals that adapted lines have evolved different features of adaptation to cope with NaCl stress. 相似文献
20.
Hui Chen Rui An Jiang-Hua Tang Xiang-Huan Cui Fu-Shun Hao Jia Chen Xue-Chen Wang 《Molecular breeding : new strategies in plant improvement》2007,19(3):215-225
To develop a salt-tolerant upland rice cultivar (Oryza sativa L.), OsNHX1, a vacuolar-type Na+/H+ antiporter gene from rice was transferred into the genome of an upland rice cultivar (IRAT109), using an Agrobacterium-mediated method. Seven independent transgenic calli lines were identified by polymerase chain reaction (PCR) analysis. These
35S::OsNHX1 transgenic plants displayed a little accelerated growth during seedling stage but showed delayed flowering time and a slight
growth retardation phenotype during late vegetative stage, suggesting that the OsNHX1 has a novel function in plant development. Northern and western blot analyses showed that the expression levels of OsNHX1 mRNA and protein in the leaves of three independent transgenic plant lines were significantly higher than in the leaves of
wild type (WT) plants. T2 generation plants exhibited increased salt tolerance, showing delayed appearance and development of damage or death caused
by salt stress, as well as improved recovery upon removal from this condition. Several physiological traits, such as increased
Na+ content, and decreased osmotic potential in transgenic plants grown in high saline concentrations, further indicated that
the transgenic plants had enhanced salt tolerance. Our results suggest the potential use of these transgenic plants for further
agricultural applications in saline soil. 相似文献