100mM Of NaCl Research Articles

Data-Mining of Barley to Identify Salt Stress Hub Genes, Gene Expression Analysis and Recombinant Plasmid Construction.

Salinity is one of the major abiotic stresses that limit the production and yields of agricultural crops worldwide. In order to identify key barley genes under salinity stress, the available metadata were examined by two methods of Cytoscape and R software. Next, the hub expression of the selected gene was evaluated under different salinity stress treatments and finally, this gene was cloned into cloning and expression vector and recombinant plasmid was made. In this study, we extracted salinity stress tolerant genes from several kinds of literature and also microarray data related to barley under salinity conditions from various datasets. The list of genes related to literature analyzed using string and Cytoscape. The genes from the datasets were first filtered and then the hub genes were identified by Cytoscape and R methods. Next, these hub genes were analyzed for the promoter. Ten hub genes were selected and their promoters were analyzed, the cis-element of which was often cis-acting regulatory element involved in the methyl jasmonate -responsiveness, common cis-acting element in promoter and enhancer regions and MYBHv1 binding site. Finally, the sedoheptulose-1,7-bisphosp gene (SBPase), which had the highest interaction in both gene lists and both types of gene networks, was selected as hub gene. Next, the expression of SBPase gene was examined in two variety of Youssef variety (salt tolerant) and Fajr variety (salt sensitive) under salinity stress (NaCl 100mM) at 0 (control), 3, 6, 12 and 24 hours after stress. The results showed that the expression of this gene increased with increasing the duration of stress in both varieties. Comparison of the two varieties showed that the expression of SBPase gene in the tolerant genotype was twice as high as sensitive. Finally, SBPase gene as a key gene for salinity stress was cloned in both cloning (pTG19) and expression (pBI121) vectors. According to our results, SBPase gene increased growth and photosynthesis in barley under various abiotic stresses, therefore, over-expression of this gene in barley is recommended to produce plants resistant to abiotic stresses.

Salinity influences arsenic resistance in the xerohalophyte Atriplex atacamensis Phil.

Arsenic (As) is a highly toxic element accumulating in the environment as a result of anthropogenic activity. In Northern Chile it accumulates in salt areas and constitutes a major threat for human population. Atriplex atacamensis is a perennial halophyte shrub spontaneously growing in these contaminated areas. In order to determine the impact of salinity on As absorption and accumulation in A. atacamensis, young seedlings obtained from seeds collected on an As-polluted area were cultivated for 2 and 4 weeks in nutrient solutions containing no As and no NaCl (control), NaCl 100mM, As(V) 1000μM and NaCl 100mM+As(V) 1000μM. Speciation analysis indicates that arsenic in the solution remained in the As(V) form. Roots accumulated high concentration of As (up to 5020μgg−1 DW): 55% of total extractable As was in the reduced state As(III) and 45% as As(V). More than half of the total As accumulated in cell walls. The leaves accumulated lower amounts of total As, with a majority of As(V) in the extractable fraction. Addition of NaCl to the As-containing nutrient solution reduced As concentration in the roots and increased the proportion of As(V) comparatively to As(III). Salinity strongly increased As translocation from the root to the shoot but did not modify its distribution between apoplasm and symplasm compartments. Exogenous salinity reduced the As-induced senescing ethylene synthesis in As-treated plants and contributed to a more efficient antioxydation system. Salinity and As induced the synthesis of major protective molecules (proline, glycinebetaine, trigonelline, polyamines, non-protein thiols), some of them being involved in short-term response to ion toxicities while others appeared to be required for longer period. It is concluded that Atriplex atacamensis is an interesting tool for the phytomanagement of As-contaminated area and that salinity improves the plant resistance to this dangerous pollutant.

Can elevated CO 2 improve salt tolerance in olive trees?

We compared growth, leaf gas exchange characteristics, water relations, chlorophyll fluorescence, and Na(+) and Cl(-) concentration of two cultivars ('Koroneiki' and 'Picual') of olive (Olea europaea L.) trees in response to high salinity (NaCl 100mM) and elevated CO(2) (eCO(2)) concentration (700microLL(-1)). The cultivar 'Koroneiki' is considered to be more salt sensitive than the relatively salt-tolerant 'Picual'. After 3 months of treatment, the 9-month-old cuttings of 'Koroneiki' had significantly greater shoot growth, and net CO(2) assimilation (A(CO(2))) at eCO(2) than at ambient CO(2), but this difference disappeared under salt stress. Growth and A(CO(2)) of 'Picual' did not respond to eCO(2) regardless of salinity treatment. Stomatal conductance (g(s)) and leaf transpiration were decreased at eCO(2) such that leaf water use efficiency (WUE) increased in both cultivars regardless of saline treatment. Salt stress increased leaf Na(+) and Cl(-) concentration, reduced growth and leaf osmotic potential, but increased leaf turgor compared with non-salinized control plants of both cultivars. Salinity decreased A(CO(2)), g(s), and WUE, but internal CO(2) concentrations in the mesophyll were not affected. eCO(2) increased the sensitivity of PSII and chlorophyll concentration to salinity. eCO(2) did not affect leaf or root Na(+) or Cl(-) concentrations in salt-tolerant 'Picual', but eCO(2) decreased leaf and root Na(+) concentration and root Cl(-) concentration in the more salt-sensitive 'Koroneiki'. Na(+) and Cl(-) accumulation was associated with the lower water use in 'Koroneiki' but not in 'Picual'. Although eCO(2) increased WUE in salinized leaves and decreased salt ion uptake in the relatively salt-tolerant 'Koroneiki', growth of these young olive trees was not affected by eCO(2).

海洋細菌の無機塩要求性に関する生理学的研究 Ｖ 細胞質膜のこはく酸酸化における無機塩要求性

In order to investigate the mechanism of the type-specific salt requirements for the succinic acid oxidations of M (marine)-, MH(marine halophilic)-, (terrestrial halophilic)-and T (terrestrial)-types, salt requirements for the succinic acid oxidations of the cytoplasmic membrane and cytoplasm were studied with the Warburg respiro-meter. Penicillin-induced spheroplasts of M-, MH-, TH- and T-types were obtained in hypertonic media containing sucrose, MgCl2 and 400 units per ml of penicillin Gas described in the previous paper. Harvested spheroplasts were disrupted in a hypotonic tris-buffer solution (pH 7.4) containing no salt, and washed five times with the same solution. Upon centrifugation, the supernatant was taken as the cytoplasm fraction and the debris was obtained as the cytoplasmic membrane fraction.The activity of the succinic acid oxidation was localized in the cytoplasmic membrane fraction but not in the cytoplasm, the former requiring the following salts for optimum oxidation at 25°C: M-type, CaCl2 5mM+MgCl2 10mM+MgSO4 10mM; MH-type, NaCl 140mM+MgCl2 5mM;TH-type, NaCl 100mM+CaCl2 20mM; T-type, none.The Na+ and K+ requirements which are characteristic of intact cells disappeared completely in the cytoplasmic membrane fraction of M-type, and the K+ requirement also disappeared in the case of the MH- TH- and T-types, respectively. On the other hand, cell membrane fraction (cell wall plus cytoplasmic membrane) prepared from lyzed cells fractionated by sucrose density gradient centrifugation, indicated the same salt requirements as did the cytoplasmic membrane fraction. The findings regarding salt requirements for the succinic acid oxidation supported three points: first, oxidizing enzymes are localized in the cytoplasmic membrane; second, the type-specific salt requirements of M-, MH-, TH- and T-types are attributed to these oxidizing enzymes; third, Na+ and K+ for M-type, and K+ for the other types play important roles in other physiological processes but not in the oxidation of substrates.