Halotolerant bacteria get adapted to a saline environment through modified physiological/structural characteristics and may provide stress tolerance along with enhanced growth to the host plants by different direct and indirect mechanisms. This study reports on multiple halotolerant plant growth-promoting rhizobacteria isolated from the coastal soils in Bangladesh, in fields where the halophytic wild rice Oryza coarctata is endemic. The aim was to find halotolerant bacteria for potential use as biofertilizer under normal/salt-stressed conditions. In this study, eight different strains were selected from a total of 20 rhizobacterial isolates from the saline-prone regions of Debhata and Satkhira based on their higher salt tolerance. 16S rRNA gene sequencing results of the rhizobacterial strains revealed that they belonged to Halobacillus, Bacillus, Acinetobactor, and Enterobactor genera. A total of ten halotolerant rhizobacteria (the other 2 bacteria were previously isolated and already reported as beneficial for rice growth) were used as both single inoculants and in combinations and applied to rice growing in pots. To investigate their capability to improve rice growth, physiological parameters such as shoot and root length and weight, chlorophyll content at the seedling stage as well as survival and yield at the reproductive stage were measured in the absence or presence (in concentration 40 or 80 mmol/L) of NaCl and in the absence or presence of the rhizobacteria. At the reproductive stage, only 50% of the uninoculated plants survived without setting any grains in 80 mmol/L NaCl in contrast to 100% survival of the rice plants inoculated with a combination of the rhizobacteria. The combined halotolerant rhizobacterial inoculations showed significantly higher chlorophyll retention as well as yield under the maximum NaCl concentration applied compared to application of single species. Thus, the use of a combination of halotolerant rhizobacteria as bioinoculants for rice plants under moderate salinity can synergistically alleviate the effects of stress and promote rice growth and yield.
Cross-talk between exogenous salicylic acid (SA) and endogenous phytohormone pathways affects the antioxidant defense system and its response to salt stress. The study presented here investigated the effects of SA treatment before and during salt stress on the levels of endogenous plant growth regulators in three barley cultivars with different salinity tolerances: Hordeum vulgare L. cvs. Akhisar (sensitive), Erginel (moderate), and Kalaycı (tolerant). The cultivars' relative leaf water contents, growth parameters, proline contents, chlorophyll a/b ratios, and lipid peroxidation levels were measured, along with the activities of enzymes involved in detoxifying reactive oxygen species (ROS) including superoxide-dismutase, peroxidase, catalase, ascorbate-peroxidase, and glutathione-reductase. In addition, levels of several endogenous phytohormones (indole-3-acetic-acid, cytokinins, abscisic acid, jasmonic acid, and ethylene) were measured. Barley is known to be more salt tolerant than related plant species. Accordingly, none of the studied cultivars exhibited changes in membrane lipid peroxidation under salt stress. However, they responded differently to salt-stress with respect to their accumulation of phytohormones and antioxidant enzyme activity. The strongest and weakest increases in ABA and proline accumulation were observed in Kalaycı and Akhisar, respectively, suggesting that salt-stress was more effectively managed in Kalaycı. The effects of exogenous SA treatment depended on both the timing of the treatment and the cultivar to which it was applied. In general, however, where SA helped mitigate salt stress, it appeared to do so by increasing ROS scavenging capacity and antioxidant enzyme activity. SA treatment also induced changes in phytohormone levels, presumably as a consequence of SA-phytohormone salt-stress cross-talk.
- MeSH
- antioxidancia metabolismus MeSH
- biomasa MeSH
- časové faktory MeSH
- chlorofyl a metabolismus MeSH
- chlorofyl metabolismus MeSH
- ječmen (rod) účinky léků růst a vývoj fyziologie MeSH
- kyselina salicylová farmakologie MeSH
- látky reagující s kyselinou thiobarbiturovou metabolismus MeSH
- listy rostlin účinky léků fyziologie MeSH
- prolin metabolismus MeSH
- reaktivní formy kyslíku metabolismus MeSH
- regulátory růstu rostlin farmakologie MeSH
- solný stres účinky léků MeSH
- voda MeSH
- výhonky rostlin účinky léků růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A systematic study on the lack of dissimilatory nitrate reductase (NAR) properties in Halomonas strains had been reported so far. The effects of different factors on Halomonas sp. B01 NAR activity were investigated. The salt tolerance of NAR was characterized. The denitrification process under high salt conditions was reported. Halomonas sp. B01 expressed membrane-bound NAR under induced culture by nitrate. The optimum pH of the enzyme reaction system was 8, and the optimum temperature was 30 °C. The mRNA expression abundance of narH in NAR encoding gene was highest in the 60 g/L NaCl inducing matrix. The NaCl concentration of optimum growth and induction of NAR were both 60 g/L. The ectoine added to the NAR vitro enzyme reaction system could maintain NAR activity under high NaCl concentration. In the range of 0-60 g/L NaCl, the NAR activity was stable at 17.7 (± 0.3) U/mg. The denitrification was performed by Halomonas sp. B01 at 60 g/L NaCl, and the denitrification rate reached 97.1% at 24 h. This study reveals for the first time the NAR properties of Halomonas strains, which provides a theoretical and technical basis for the nitrogen removal of high-salt nitrogenous wastewater using this strain.
- MeSH
- aminokyseliny diaminové metabolismus MeSH
- bakteriální proteiny genetika metabolismus MeSH
- buněčná membrána metabolismus MeSH
- chlorid sodný metabolismus MeSH
- denitrifikace MeSH
- dusičnany metabolismus MeSH
- Halomonas enzymologie genetika růst a vývoj metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- nitrátreduktasa genetika metabolismus MeSH
- regulace genové exprese u bakterií MeSH
- teplota MeSH
- tolerance k soli * MeSH
- Publikační typ
- časopisecké články MeSH
Halophilic bacterias from saline soil from former Lake Texcoco were isolated, identified based on 16 rRNA and tested to produce glucolytic, nucleolytic, proteolytic and lipolytic exoenzymes. The Bacillus, Virgibacillus, Kocuria, Salinicoccus, Gracilibacillus, Halobacillus, Tenuibacillus and Nesterekonia genera where identified. Lipase/eserases and proteases from Nesterenkonia sp. and Nesterenkonia aethiopica showed halotolerant characteristics and were selected to synthesize the oleochemical n-butyl oleate and antioxidant peptides from muscle protein of common carp (Cyprinus carpio), respectively. In organic media (2,2,4-Trimethylpentane), the lipase/esterases from Nesterenkonia sp. (0.6 U/mL) and N. aethiopica (1.2 U/mL) achieved a 62.7% and 53.2% of n-butyl oleate conversion, respectively. The protein hydrolysis from muscle of common carp (C. carpio) showed a degree of hydrolysis of 4.5 ± 0.2% and 2.8 ± 0.1% when proteases from Nesterenkonia sp. and N. aethiopica were used, respectively. Three peptidic fractions ranging molecular masses between 254 and 1002 Da [M + H] show antioxidant scavenging activity, and the principal fraction with a peptide of 547.3 Da [M + H] showed an inhibition of 37.7 ± 1.8% and 16.3 ± 0.6%, when 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) were used, respectively. These findings showed that the enzymatic battery of the halophilic bacteria from former lake Texcoco can be used in hydrolysis and synthesis of molecules with applications in different fields as food technology or bioenergy.
- MeSH
- antioxidancia chemie metabolismus MeSH
- Bacteria klasifikace genetika izolace a purifikace metabolismus MeSH
- bakteriální proteiny metabolismus MeSH
- esterasy metabolismus MeSH
- fylogeneze MeSH
- hydrolýza MeSH
- jezera MeSH
- kapři metabolismus MeSH
- kyseliny olejové metabolismus MeSH
- lipasa metabolismus MeSH
- peptidy chemie metabolismus MeSH
- proteasy metabolismus MeSH
- půdní mikrobiologie MeSH
- RNA ribozomální 16S genetika MeSH
- tolerance k soli * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
This is the first exhaustive report on the fungal community biodiversity in hypersaline water in România. A total of 27 fungal strains (19 molds and eight yeast) have been isolated from Lopătari hypersaline water, Buzau County. Based on classical investigation, these strains have been identified as belonging to the genera Aureobasidium, Alternaria, Aspergillus, Penicillium, and Fusarium. The molecular characterization of fungal isolates at species level was performed using PCR-RFLP analysis of the 5.8S-ITS region. PCR products were digested with different combinations of endonucleases. The most frequently isolated species were Aspergillus niger (14.81% of all isolates), A. versicolor, (14.81%) and Penicillium crustosum (14.81%). In addition, ribosomal restriction patterns which exhibited profiles specific to Aureobasidium pullulans were derived, and to discriminate between Aureobasidium isolates, the elongase-encoding gene (ELO) was chosen as a genetic marker followed by digestion with endonuclease HhaI. Five yeast isolates displayed restriction patterns corresponding to Aureobasidium melanogenum (18.52%) and three isolates to Aureobasidium pullulans (11.11%). In addition, the RFLP types of Aureobasidium pullulans varieties with HhaI are clearly distinguished and could be applied to assess the intraspecific variability.
- MeSH
- Ascomycota genetika izolace a purifikace metabolismus MeSH
- Aspergillus genetika izolace a purifikace metabolismus MeSH
- biodiverzita MeSH
- DNA fungální genetika MeSH
- fylogeneze MeSH
- houby klasifikace genetika izolace a purifikace MeSH
- kvasinky genetika izolace a purifikace metabolismus MeSH
- mikrobiologie vody * MeSH
- polymerázová řetězová reakce MeSH
- polymorfismus délky restrikčních fragmentů * MeSH
- řeky chemie mikrobiologie MeSH
- ribozomální DNA genetika MeSH
- sekvenční analýza DNA MeSH
- slané vody * MeSH
- tolerance k soli * MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Rumunsko MeSH
High-salt intake is one of the major dietary determinants of increased blood pressure and cardiovascular disease. Thus, there is scientific and medical interest in understanding the mechanistic abnormalities mediating the pressor effects of salt (salt sensitivity). According to historical theory, salt sensitivity stems from an impairment in renal function (referred to as "abnormal pressure natriuresis" or a "natriuretic handicap"), which causes salt-sensitive subjects to excrete a sodium load more slowly, and retain more of it than salt-resistant normotensive controls. However, this historical view has come under intense scrutiny because of growing awareness that in salt-sensitive subjects, acute salt loading does not usually induce greater increases in sodium balance and cardiac output than those induced by salt loading in salt-resistant normotensive controls. Here we highlight pioneering studies from Japan that challenge the historical thinking and provide insights into a contemporary theory of salt sensitivity termed the "vasodysfunction theory." According to this theory, initiation of salt-induced hypertension usually involves abnormal vascular resistance responses to increased salt intake, not greater renal retention of a salt load in salt-sensitive subjects than in normal subjects. By shifting the focus from the historical theory to a contemporary final common pathway for the pathogenesis of salt sensitivity, research from Japan is building the scientific foundation for more effective approaches to the prevention and treatment of salt-induced hypertension. Among the most promising approaches are dietary strategies for reducing the risk for salt-induced hypertension that do not depend on reducing salt consumption in the population.
- MeSH
- arginin analogy a deriváty metabolismus MeSH
- cévní rezistence * MeSH
- dieta MeSH
- hypertenze etiologie prevence a kontrola MeSH
- kuchyňská sůl škodlivé účinky MeSH
- lidé MeSH
- oxid dusnatý metabolismus MeSH
- renální oběh * MeSH
- sodík moč MeSH
- solný stres MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Research Support, N.I.H., Extramural MeSH
We studied the resistance of Parmotrema austrosinense to UV-B stress. We focused on the effects of a high dose UV-B radiation on the content of chlorophylls, carotenoids and UV-B screening compounds. Photosynthetic parameters were measured by chlorophyll fluorescence (potential and effective quantum yields, photochemical and non-photochemical quenching) and evaluated in control and UV-B-treated lichens. Lichens from two different locations in Cordoba, Argentina, were selected: (i) high altitude and dry plots at (Los Gigantes) and (ii) lowland high salinity plots (Salinas Grandes). UV-B treatment led to a decrease in the content of photosynthetic pigments and UV-B screens (absorbance decrease in 220-350 nm) in the samples from Salinas Grandes, while in Los Gigantes samples, an increase in UV-B screen content was observed. Chlorophyll fluorescence parameters showed a UV-B-induced decline in FV /FM , ΦPSII and qP indicating limitation of primary photosynthetic processes in photosystem II (PSII) of symbiotic alga, more pronounced in Salinas Grandes samples. Protective mechanism of PSII were activated by the UV-B treatment to a higher extent in samples from Salinas Grandes (NPQ 0.48) than in Los Gigantes samples (NPQ 0.26). We concluded that site-related characteristics, and in particular different UV-B radiation regimen, had a strong effect on resistance of the photosynthetic apparatus of P. austrosinense to UV-B radiation.
- MeSH
- chlorofyl analýza metabolismus MeSH
- ekosystém MeSH
- fluorescence MeSH
- fotosyntéza účinky záření MeSH
- karotenoidy analýza metabolismus MeSH
- lišejníky chemie metabolismus účinky záření MeSH
- nadmořská výška MeSH
- tolerance k soli účinky záření MeSH
- ultrafialové záření * MeSH
- Publikační typ
- časopisecké články MeSH
Phytohormones are physiologically important small molecules that play essential roles in intricate signaling networks that regulate diverse processes in plants. We present a method for the simultaneous targeted profiling of 101 phytohormone-related analytes from minute amounts of fresh plant material (less than 20 mg). Rapid and nonselective extraction, fast one-step sample purification, and extremely sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry enable concurrent quantification of the main phytohormone classes: cytokinins, auxins, brassinosteroids, gibberellins, jasmonates, salicylates, and abscisates. We validated this hormonomic approach in salt-stressed and control Arabidopsis (Arabidopsis thaliana) seedlings, quantifying a total of 43 endogenous compounds in both root and shoot samples. Subsequent multivariate statistical data processing and cross-validation with transcriptomic data highlighted the main hormone metabolites involved in plant adaptation to salt stress.
- MeSH
- Arabidopsis metabolismus fyziologie MeSH
- chemická frakcionace MeSH
- chromatografie kapalinová MeSH
- kořeny rostlin metabolismus MeSH
- metabolomika metody MeSH
- regulátory růstu rostlin analýza izolace a purifikace metabolismus MeSH
- reprodukovatelnost výsledků MeSH
- solný stres MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- výhonky rostlin metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
S. kudriavzevii has potential for fermentations and other biotechnological applications, but is sensitive to many types of stress. We tried to increase its tolerance and performance via the expression of various transporters from different yeast species. Whereas the overexpression of Z. rouxii fructose uptake systems (ZrFfz1 and ZrFsy1) or a glycerol importer (ZrStl1) did not improve the ability of S. kudriavzevii to consume fructose and survive osmotic stress, the expression of alkali-metal-cation exporters (ScEna1, ScNha1, YlNha2) improved S. kudriavzevii salt tolerance, and that of ScNha1 also the fermentation performance. The level of improvement depended on the type and activity of the transporter suggesting that the natural sensitivity of S. kudriavzevii cells to salts is based on a non-optimal functioning of its own transporters.
- MeSH
- fermentace MeSH
- fruktosa metabolismus MeSH
- glycerol metabolismus MeSH
- iontový transport fyziologie MeSH
- osmotický tlak fyziologie MeSH
- proteiny přenášející kationty genetika metabolismus MeSH
- Saccharomyces metabolismus MeSH
- sušené kvasnice MeSH
- tolerance k soli fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
Substantial increases in cardiac output (CO), stroke volume (SV), and gastrointestinal blood flow are essential for euryhaline rainbow trout (Oncorhyncus mykiss) osmoregulation in seawater. However, the underlying hemodynamic mechanisms responsible for these changes are unknown. By examining a range of circulatory and cardiac morphological variables of seawater- and freshwater-acclimated rainbow trout, the present study revealed a significantly higher central venous pressure (CVP) in seawater-acclimated trout (~0.09 vs. -0.02 kPa). This serves to increase cardiac end-diastolic volume in seawater and explains the elevations in SV (~0.41 vs. 0.27 ml/kg) and CO (~21.5 vs. 14.2 ml·min(-1)·kg(-1)) when compared with trout in freshwater. Furthermore, these hemodynamic modifications coincided with a significant increase in the proportion of compact myocardium, which may be necessary to compensate for the increased wall tension associated with a larger stroke volume. Following a temperature increase from 10 to 16.5°C, both acclimation groups exhibited similar increases in heart rate (Q10 of ~2), but SV tended to decrease in seawater-acclimated trout despite the fact that CVP was maintained in both groups. This resulted in CO of seawater- and freshwater-acclimated trout stabilizing at a similar level after warming (~26 ml·min(-1)·kg(-1)). The consistently higher CVP of seawater-acclimated trout suggests that factors other than compromised cardiac filling constrained the SV and CO of these individuals at high temperatures. The present study highlights, for the first time, the complex interacting effects of temperature and water salinity on cardiovascular responses in a euryhaline fish species.
- MeSH
- centrální žilní tlak fyziologie MeSH
- minutový srdeční výdej fyziologie MeSH
- mořská voda * MeSH
- Oncorhynchus mykiss fyziologie MeSH
- osmoregulace fyziologie MeSH
- remodelace komor fyziologie MeSH
- tepový objem fyziologie MeSH
- tolerance k soli fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
