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1.
A novel zinc-finger-like gene from <Emphasis Type="Italic">Tamarix hispida</Emphasis> is involved in salt and osmotic tolerance 总被引:1,自引:0,他引:1
In the present study, a zinc-finger-like cDNA (ThZFL) was cloned from the Tamarix hispida. Northern blot analysis showed that the expression of ThZFL can be induced by salt, osmotic stress and ABA treatment. Overexpression of the ThZFL confers salt and osmotic stress tolerance in both yeast Saccharomyces cerevisiae and tobacco. Furthermore, MDA levels in ThZFL transformed tobacco were significantly decreased compared with control plants under salt and osmotic stress, suggesting ThZFL may confer stress tolerance by decreasing membrane lipid peroxidation. Subcellular localization analysis showed the ThZFL
protein is localized in the cell wall. Our results indicated the ThZFL gene is an excellent candidate for genetic engineering to improve salt and osmotic tolerance in agricultural plants. 相似文献
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Jianhua Zhu Byeong‐Ha Lee Mike Dellinger Xinping Cui Changqing Zhang Shang Wu Eugene A. Nothnagel Jian‐Kang Zhu 《The Plant journal : for cell and molecular biology》2010,63(1):128-140
Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root‐bending assay have previously identified salt overly sensitive (sos) mutants of Arabidopsis that fall into five loci, SOS1 to SOS5. These loci are required for the regulation of ion homeostasis or cell expansion under salt stress, but do not play a major role in plant tolerance to the osmotic stress component of soil salinity or drought. Here we report an additional sos mutant, sos6‐1, which defines a locus essential for osmotic stress tolerance. sos6‐1 plants are hypersensitive to salt stress and osmotic stress imposed by mannitol or polyethylene glycol in culture media or by water deficit in the soil. SOS6 encodes a cellulose synthase‐like protein, AtCSLD5. Only modest differences in cell wall chemical composition could be detected, but we found that sos6‐1 mutant plants accumulate high levels of reactive oxygen species (ROS) under osmotic stress and are hypersensitive to the oxidative stress reagent methyl viologen. The results suggest that SOS6/AtCSLD5 is not required for normal plant growth and development but has a critical role in osmotic stress tolerance and this function likely involves its regulation of ROS under stress. 相似文献
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I. Esteves B. Peteira S. Powers N. Magan B.R. Kerry 《Biocontrol Science and Technology》2009,19(2):185-199
For the first time, the effects of varying osmotic and matric potential on fungal radial growth and accumulation of polyols were studied in three isolates of Pochonia chlamydosporia. Fungal radial growth was measured on potato dextrose agar modified osmotically using potassium chloride or glycerol. PEG 8000 was used to modify matric potential. When plotted, the radii of the colonies were found to grow linearly with time, and regression was applied to estimate the radial growth rate (mm day?1). Samples of fresh mycelia from 25-day-old cultures were collected and the quantity (mg g?1 fresh biomass) of four polyols (glycerol, erythritol, arabitol and mannitol) and one sugar (glucose) was determined using HPLC. Results revealed that fungal radial growth rates decreased with increased osmotic or matric stress. Statistically significant differences in radial growth were found between isolates in response to matric stress (P<0.006) but not in response to osmotic stress (P=0.759). Similarly, differences in the total amounts of polyols accumulated by the fungus were found between isolates in response to matric stress (P<0.001), but not in response to osmotic stress (P=0.952). Under water stress, the fungus accumulated a combination of different polyols important in osmoregulation, which depended on the solute used to generate the stress. Arabitol and glycerol were the main polyols accumulated in osmotically modified media, whereas erythritol was the main polyol that was accumulated in media amended with PEG. The results found that Pochonia chlamydosporia may use different osmoregulation mechanisms to overcome osmotic and matric stresses. 相似文献
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Genome‐wide transcriptome analysis of Aspergillus fumigatus exposed to osmotic stress reveals regulators of osmotic and cell wall stresses that are SakAHOG1 and MpkC dependent 下载免费PDF全文
Lilian Pereira Silva Patrícia Alves de Castro Thaila Fernanda dos Reis Mario Henrique Paziani Márcia Regina Von Zeska Kress Diego M. Riaño‐Pachón Daisuke Hagiwara Laure N. A. Ries Neil Andrew Brown Gustavo H. Goldman 《Cellular microbiology》2017,19(4)
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Adrian R. N. E. Brüning Jürgen Bauer Bernhard Krems Karl-Dieter Entian B. A. Prior 《Archives of microbiology》1998,170(2):99-105
The screening of 20,000 Saccharomyces cerevisiae random mutants to identify genes involved in the osmotic stress response yielded 14 mutants whose growth was poor in the
presence of elevated concentrations of NaCl and glucose. Most of the mutant strains were more sensitive to NaCl than to glucose
at the equivalent water activity (aw) and were classified as salt-sensitive rather than osmosensitive. These mutants fell into 11 genetic complementation groups
and were designated osr1–osr11 (osmotic stress response). All mutations were recessive and showed a clear 2+ : 2– segregation of the salt-stress phenotype upon tetrad analysis when crossed to a wild-type strain. The complementation groups
osr1, osr5 and osr11 were allelic to the genes PBS2, GPD1 and KAR3, respectively. Whereas intracellular and extracellular levels of glycerol increased in the wild-type strains when exposed
to NaCl, all mutants demonstrated some increase in extracellular glycerol production upon salt stress, but a number of the
mutants showed little or no increase in intracellular glycerol concentrations. The mutants had levels of glycerol-3-phosphate
dehydrogenase, an enzyme induced by osmotic stress, either lower than or similar to those of the parent wild-type strain in
the absence of osmotic stress. In the presence of NaCl, the increase in glycerol-3-phosphate dehydrogenase activity in the
mutants did not match that of the parent wild-type strain. None of the mutants had defective ATPases or were sensitive to
heat stress. It is evident from this study and from others that a wide spectrum of genes is involved in the osmotic stress
response in S. cerevisiae.
Received: 5 January 1998 / Accepted: 24 March 1998 相似文献
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The physiological effects of the rare earth ion La3+ on the peroxidation of membrane lipids in wheat (Triticum aestivum L.) seedling leaves under osmotic stress were determined. With the passage of time under osmotic stress, the inhibition ability
of lanthanum ions to the relative membrane permeability and concentration of malondialdehyde, Superoxide radicals, and hydrogen
peroxide caused by osmotic stress increased substantially, but no changes were noted in ferrous and relative water content.
It indicated that lanthanum ions could not retain the water content because of osmotic stress. However, La3+ appears to decrease the production of OH by reducing the content of O2 and H2O2 of Haber-Weiss and Fenton reactions, which efficiently alleviated peroxidation of membrane lipids under osmotic stress and,
to some degree, protected the membrane from injury of free radicals. Thus, La3+ increased the tolerance ability of plant to osmotic stress, which could assure the function of membrane normal temporally
after stressed. 相似文献
9.
Potassium accumulation is an essential aspect of bacterial response to diverse stress situations; consequently its uptake
plays a pivotal role. Here, we show that the Gram-positive soil bacterium Corynebacterium glutamicum which is employed for the large-scale industrial production of amino acids requires potassium under conditions of ionic and
non-ionic osmotic stress. Besides the accumulation of high concentrations of potassium contributing significantly to the osmotic
potential of the cytoplasm, we demonstrate that glutamate is not the counter ion for potassium under these conditions. Interestingly,
potassium is required for the activation of osmotic stress-dependent expression of the genes betP and proP. The Kup-type potassium transport system which is present in C. glutamicum in addition to the potassium channel CglK does not contribute to potassium uptake at conditions of hyperosmotic stress. Furthermore,
we established a secondary carrier of the KtrAB type from C. jeikeium in C. glutamicum thus providing an experimental comparison of channel- and carrier-mediated potassium uptake under osmotic stress. While at
low potassium availability, the presence of the KtrAB transporter improves both potassium accumulation and growth of C. glutamicum upon osmotic stress, at proper potassium supply, the channel CglK is sufficient. 相似文献
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ERMIAS HABTE LUKAS M. MÜLLER MUNQEZ SHTAYA SETH J. DAVIS MARIA VON KORFF 《Plant, cell & environment》2014,37(6):1321-1337
The circadian clock is an important timing system that controls physiological responses to abiotic stresses in plants. However, there is little information on the effects of the clock on stress adaptation in important crops, like barley. In addition, we do not know how osmotic stress perceived at the roots affect the shoot circadian clock. Barley genotypes, carrying natural variation at the photoperiod response and clock genes Ppd‐H1 and HvELF3, were grown under control and osmotic stress conditions to record changes in the diurnal expression of clock and stress‐response genes and in physiological traits. Variation at HvELF3 affected the expression phase and shape of clock and stress‐response genes, while variation at Ppd‐H1 only affected the expression levels of stress genes. Osmotic stress up‐regulated expression of clock and stress‐response genes and advanced their expression peaks. Clock genes controlled the expression of stress‐response genes, but had minor effects on gas exchange and leaf transpiration. This study demonstrated that osmotic stress at the barley root altered clock gene expression in the shoot and acted as a spatial input signal into the clock. Unlike in Arabidopsis, barley primary assimilation was less controlled by the clock and more responsive to environmental perturbations, such as osmotic stress. 相似文献
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Tino Kreszies Stella Eggels Victoria Kreszies Alina Osthoff Nandhini Shellakkutti Jutta A. Baldauf Viktoria V. Zeisler-Diehl Frank Hochholdinger Kosala Ranathunge Lukas Schreiber 《Plant, cell & environment》2020,43(2):344-357
Wild barley, Hordeum vulgare spp. spontaneum, has a wider genetic diversity than its cultivated progeny, Hordeum vulgare spp. vulgare. Osmotic stress leads to a series of different responses in wild barley seminal roots, ranging from no changes in suberization to enhanced endodermal suberization of certain zones and the formation of a suberized exodermis, which was not observed in the modern cultivars studied so far. Further, as a response to osmotic stress, the hydraulic conductivity of roots was not affected in wild barley, but it was 2.5-fold reduced in cultivated barley. In both subspecies, osmotic adjustment by increasing proline concentration and decreasing osmotic potential in roots was observed. RNA-sequencing indicated that the regulation of suberin biosynthesis and water transport via aquaporins were different between wild and cultivated barley. These results indicate that wild barley uses different strategies to cope with osmotic stress compared with cultivated barley. Thus, it seems that wild barley is better adapted to cope with osmotic stress by maintaining a significantly higher hydraulic conductivity of roots during water deficit. 相似文献
15.
Adriana Marulanda José-Miguel Barea Rosario Azcón 《Journal of Plant Growth Regulation》2009,28(2):115-124
In this study we tested whether rhizosphere microorganisms can increase drought tolerance to plants growing under water-limitation
conditions. Three indigenous bacterial strains isolated from droughted soil and identified as Pseudomonas putida, Pseudomonas sp., and Bacillus megaterium were able to stimulate plant growth under dry conditions. When the bacteria were grown in axenic culture at increasing osmotic
stress caused by polyethylene glycol (PEG) levels (from 0 to 60%) they showed osmotic tolerance and only Pseudomonas sp. decreased indol acetic acid (IAA) production concomitantly with an increase of osmotic stress (PEG) in the medium. P. putida and B. megaterium exhibited the highest osmotic tolerance and both strains also showed increased proline content, involved in osmotic cellular
adaptation, as much as increased osmotic stress caused by NaCl supply. These bacteria seem to have developed mechanisms to
cope with drought stress. The increase in IAA production by P. putida and B. megaterium at a PEG concentration of 60% is an indication of bacterial resistance to drought. Their inoculation increased shoot and
root biomass and water content under drought conditions. Bacterial IAA production under stressed conditions may explain their
effectiveness in promoting plant growth and shoot water content increasing plant drought tolerance. B. megaterium was the most efficient bacteria under drought (in successive harvests) either applied alone or associated with the autochthonous
arbuscular mycorrhizal fungi Glomus coronatum, Glomus constrictum or Glomus claroideum.
B. megaterium colonized the rhizosphere and endorhizosphere zone. We can say, therefore, that microbial activities of adapted strains represent
a positive effect on plant development under drought conditions. 相似文献
16.
Gu Ruisheng Liu Qiunlu Pei Dong Jiang Xiangning 《Plant Cell, Tissue and Organ Culture》2004,78(3):261-265
Tolerance of Populus euphratica suspended cells to ionic and osmotic stresses implemented respectively by NaCl and PEG (6000) was characterized by monitoring
cell growth, morphological features, ion compartmentation and polypeptide patterns. The cells grew and proliferated when submitted
to stresses of 137 mM NaCl or 250 g l−1 PEG, and survived at 308 mM of NaCl, showing tolerance to saline and particularly osmotic stress. They were resistant to
plasmolysis and had dense cytoplasms, large nuclei and nucleoli, and evident cytoplasmic strands under high saline and osmotic
stress. The sequestration of Cl− into the vacuoles was observed in the cells stressed with 137 and 223 mM NaCl. The cellular protein profile was modified
by high salt and osmotic stress and showed 28 kDa polypeptides up-regulated by both NaCl and PEG, and 66 and 25 kDa polypeptides
up-regulated only by high NaCl stress. The salt tolerance of P. euphratica cells might be related to their capacity of adapting to higher osmotic stress by maintaining cell integrity, sequestrating
Cl− into vacuoles and modulating polypeptides that reflect cellular metabolic adaptations. 相似文献
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R. E. Redmann 《Oecologia》1976,23(4):283-295
Summary Seasonal and diurnal patterns of osmotic and leaf water potential of several mixed grassland species were studied. The osmotic potential (OP) of Agropyron dasystachyum ranged from about-15 bars early in the growing season to about-30 bars during late summer droughts. Seasonal trends in A. smithii and Koeleria cristata were similar. Minimum osmotic potentials of Eurotia lanata and Artemisia frigida were-42 and-35 bars, respectively. The mesophytes Geum triflorum and Lomatium foeniculaceum did not exhibit OP below-20 bars. Soil water, particularly in the 0–15 cm layer, strongly influenced OP and leaf water potential (WP). Seasonal trends in WP were similar to OP. Under low stress, WP was about 10 bars greater than OP; under high stress WP was equal or even lower then OP (negative turgor). Diurnal fluctuations in WP were greater than those of OP when low stress conditions existed. Diurnal changes in potential were related to global radiation which was an index of atmospheric evaporative demand. Ecological implications of water status are discussed. 相似文献
18.
Bioformulation that supports the inoculant under storage condition and on application to field is of prime importance for
agroindustry. Pseudomonas strain EKi having biocontrol activity against Macrophomina phaseolina was used in the study. EKi cells were pretreated by carbon starvation, osmotic stress (NaCl), and freeze drying conditions,
and talc-based bioformulation was developed. Combined pretreatment with carbon starvation and osmotic stress was given to
Pseudomonas cells. Bioformulation of untreated, freeze dried (FD), carbon starved, osmotic stressed, and combined pre-treated cells showed
50.36, 44.76, 45.95, 34.82, and 27.27% reduction in CFU counts after 6 months of storage. The osmotic stressed cells showed
one over-expressed protein (11.5 kDa) in common with carbon starved cells responsible for its better shelf life. The plant
growth promotory activity of bioformulations was determined taking Cicer arietinum as a test crop in M. phaseolina infested field. Carbon starved + osmotic stressed cells showed maximum enhancement of dry weight (272.56%) followed by osmotic
stressed (230.74%), untreated (155.70%), FD (88.93%), and carbon starved (59.34%) cells over uninoculated control. Carbon
starved + osmotic stressed, osmotic stressed, untreated, FD, and carbon starved cells showed 156.60, 100, 75, 40, and 16.67%
reduction of charcoal rot disease over uninoculated control. The results clearly showed that combined pretreatment by carbon
starvation and osmotic stress provides the bacteria potential of rapid adaptation to different environment conditions. 相似文献
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Symbiotic effectiveness and response to mannitol-mediated osmotic stress of various chickpea–rhizobia associations 总被引:1,自引:1,他引:0
Haythem Mhadhbi Moez Jebara Adel Zitoun Férid Limam Mohamed Elarbi Aouani 《World journal of microbiology & biotechnology》2008,24(7):1027-1035
Thirty-six symbiotic associations involving six chickpea cultivars against six rhizobial strains were evaluated for symbiotic
performance and responses to osmotic stress applied by mannitol (50 mM) in aerated hydroponic cultures. Analyses in different
symbioses were focused on biomass production, nodulation, nitrogen fixation, and their modulation under osmotic stress conditions,
as well as expression of nodular antioxidant enzymes. Mesorhizobium ciceri reference (835) and local (CMG6) strains, as well as the local (C11) M. mediterraneum allowed the best symbiotic efficiency for all chickpea cultivars. The osmotic stress induces severe decrease ranging 30–50%
in aerial biomass and 50–70% for nitrogen fixation. Nevertheless, plants inoculated with M. ciceri (835) and M. mediterraneum (C11) preserve a relatively high growth (4 g plant−1) with nitrogen-fixing activity (25 μmols h−1 plant−1). The bacterial partner was the most important factor of variance of the analysed parameters in osmotic stress or physiological
conditions where it gets to 60–85%. The strains allowing the best competent symbioses were proposed for field assays. Under
osmotic stress, nodular peroxidase (POX) and ascorbate peroxidase (APX) activities were significantly enhanced. The increase
of POX and APX was inversely correlated with the inhibition of aerial biomass production (p = 0.05) and nitrogen-fixing capacity (p = 0.01), suggesting a protective role of these enzymes in nodules. Superoxide dismutase (SOD) was also activated in stressed
nodules. However, the spectacular decrease in catalase (CAT) activity discounts its involvement in osmotic stress response. 相似文献
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Trehalose metabolism in Escherichia coli: stress protection and stress regulation of gene expression 总被引:21,自引:3,他引:18
Endogenously synthesized trehalose is a stress protectant in Escherichia coli. Externally supplied trehalose does not serve as a stress protectant, but it can be utilized as the sole source of carbon and energy. Mutants defective in trehalose synthesis display an impaired osmotic tolerance in minimal growth media without glycine betaine, and an impaired stationary-phaseinduced heat tolerance. Mechanisms for stress protection by trehalose are discussed. The genes for trehalose-6-phosphate synthase (otsA) and anabolic trehalose-6-phosphate phosphatase (otsB) constitute an operon. Their expression is induced both by osmotic stress and by growth into the stationary phase and depend on the sigma factor encoded by rpoS (katF). rpoS is amber-mutated in E. coli K-12 and its DNA sequence varies among K-12 strains. For trehalose catabolism under osmotic stress E. coli depends on the osmoticcally inducible periplasmic trehalase (TreA). In the absence of osmotic stress, trehalose induces the formation of an enzyme IITre (TreB) of the group translocation system, a catabolic trehalose-6-phosphate phosphatase (TreE), and an amylotrehalase (TreC) which converts trehalose to free glucose and a glucose polymer. 相似文献