Effect of nitrogen concentration,source, and phosphate concentration on accumulation of biomass and calycosin-7-O-β-D-glucoside in Astragalus membranaceus adventitious roots

In Vitro Cellular & Developmental Biology - Plant - Calycosin-7-O-β-D-glucoside (CG), a methoxylated isoflavonoid in Astragalus membranaceus Fisch. (Bunge), has a wide range of biological...     

Effect of Cu2+ on PSⅡ Activity and Energy Transfer of Phycobillisome in Intact Cells of Spirulina platensis

Addition of Cu2+ at low concentrations, to intact cells of the cyanobacterium, Spirulina platensis, at room temperature, caused an enhancement in intensity of fluorescence emitted by phycocyanin and induced a blue shift at the emission peak, both of which indicated changes in energy transfer within the phycobillisomes. Cu2+ also suppressed the whole-chain electron transport activity (H2O→MV) and water-splitting activity of the photosystem Ⅰ. When isolated phycocyanin and allophycocyanin were exposed to very low concentrations of Cu2+ ions, C-phycocyanin but not allophycocyanin, exhibited decrease not only in the absorbance in the longer wavelength (616--620 nm) region, but also in the fluorescence emission intensity at 647 nm accompanied by a blue shift to 643 nm. These results suggested that Cu2+ selectively bleach C-phycocyanin.     

Antioxidant and Angiostatic Effect of Spirulina platensis Suspension in Complete Freund’s Adjuvant-Induced Arthritis in Rats

Background

Currently, natural products have built a well-recognized role in the management of many degenerative diseases, mainly rheumatoid arthritis. Recent studies suggest that Spirulina, a unicellular blue-green alga, may have a variety of health benefits and curative properties and is also competent of acting as an anti-inflammatory, antioxidant and recently anti-angiogenic agent. In the present study, the antioxidant and the immunomodulatory effect of Spirulina platensis as well as its anti-angiogenic effect against complete Freund''s adjuvant-induced arthritis (AIA) in rat model were tested.

Results

We found that the development of arthritis was concealed; moreover it successfully inhibited the development of macroscopic as well as microscopic and histopathological lesions in AIA rats when compared to control. Spirulina treated group showed a higher survival rate and moreover, it reduced the clinical score of RA in a dose dependent manner. Furthermore, Spirulina decreased serum levels of COX-2, TNF-α, IL-6, TBARS, VEGF and increased serum levels of GSH compared to the RA non-treated group.

Conclusions

The present study concluded that Spirulina is able to restrain the changes produced through adjuvant-induced arthritis. The suppressing effect of Spirulina could be attributed, at least in part, to anti-inflammatory, antioxidant and anti-angiogenic properties.     

Effect of Pb pollution on the growth,biomass allocation and photosynthesis of Phragmites australis in flood and drought environment北大核心CSCD

Aims Reed (Phragmites australis) is a typical perennial rhizomatic plant with extensive tolerance to environmental stress. In order to better understand the adaptation and tolerance of reeds subjected to heavy metal pollution in different levels of water, we conducted a study on the effects of Pb pollution on growth, biomass and photosynthesis of reeds in flood and drought environment. This research would provide theoretical basis for application of reeds in wetland restoration and remediation. Methods We conducted a pot experiment with destructive sampling after 90 days of growth. The water treatments were main plot, including two water levels. The Pb treatments were secondary plot (nested within water treatments), including five levels (0, 500, 1 500, 3 000, 4 500 mg·kg–1). There were 10 treatments with 12 replicates per treatment. Important findings In the flood environment, Pb pollution significantly inhibited the growth of buds and rhizomes, but had no significant effect on the number of offspring shoots. The offspring shoots had higher growth rate per day, net photosynthetic rate and biomass compared to the parent shoots. In the drought environment, Pb pollution inhibited the growth of roots, buds and rhizomes, and biomass accumulation of parent and offspring shoots as well as photosynthetic parameters. These parameters were lower under the drought condition than in the flood environment. The Pb was mostly concentrated in roots compared to rhizomes and offspring shoots. In both flood and drought environments, the concentration of Pb in parent shoots was about three times of that in offspring shoots. The Pb concentration in offspring shoots under the flood condition was less than that in the drought environment. Overall, these results indicated that the synergistic effect of Pb and drought significantly inhibited the growth, biomass accumulation and photosynthesis of reeds, which might result in reduced offspring productivity and population density and may lead to population decline. However, the flooded reeds could adopt some strategies of Pb allocation to alleviate the negative effect of Pb on the growth, physiology and clonal propagation, benefiting the population reproduction and stabilization. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All rights reserved.     

Effect of nickel concentration and soil pH on metal accumulation and growth in tropical agromining ‘metal crops’

Plant and Soil - Phosphorus (P) deficiency is a major constraint for rice production in the tropics. Field-specific P management is key for resource-limited farmers to increase yields with minimal...     

Isolation of Biopterin-α-glucoside from Spirulina (Arthrospira) platensis and Its Physiologic Function

A fluorescent substance was isolated from the cyanobacterium with a yield of 4.5 mg per 10 g of dried Spirulina (Arthrospira) platensis cells by gentle extraction and ethanol fractionation followed by column chromatography. The fluorescent substance, which has absorption maxima at 256 nm and 362 nm (pH 8.4), was identified as biopterin-α-glucoside by spectrophotometry and nuclear magnetic resonance spectroscopy. Biopterin-α-glucoside prevented decolorization of the photosynthetic pigments, chlorophyll a, phycocyanin, and carotenoids in photosynthetic vesicles of Spirulina platensis cells, by ultraviolet irradiation. Received June 23, 1998; accepted September 10, 1998.     

Acidic polysaccharides of Arthrospira (Spirulina) platensis induce the synthesis of TNF-α in RAW macrophages

The study of the enhancement of the immune system by administration of algal cell components is a current research field of great interest for future development of algal biotechnology. Arthrospira (Spirulina) platensis is one of the key organisms, showing interesting results in the treatment of certain tumors, viral infection, and immunodeficiency. Polysaccharides from Arthrospira, together with phycocyanin, seem to be responsible for most of these positive effects. In this work, we isolated the acidic polysaccharide fraction from A. platensis and tested its capacity to induce the production of the proinflammatory cytokine tumor necrosis factor alpha in macrophages. For this purpose, we modified a previous isolation method developed by one of us, which includes several depigmentation steps, as well as differential partitioning with N-cetylpyridinium bromide (Cetavlon). Infrared spectroscopy of the acidic polysaccharide fraction indicates the presence of hydroxyl radicals, aliphatic residues, carbonyl groups, sulfate groups, and sulfate esters, as well as amine residues. Liquid chromatography confirmed the polysaccharidic nature of the fraction, revealing its high purity, essentially free of lipopolysaccharide (LPS) contamination (0.0017% w/w), and complying with international pharmacological standards. The results indicate that a very high production of tumor necrosis factor- α (TNF?α) occurred in macrophages in the presence of the polysaccharides in the range 5–100 μg mL^?1, reaching values of 8 ng TNF-α mL^?1 after 24 h and 30 ng TNF-α mL^?1 after 48 h. These data demonstrate that acidic polysaccharides from Spirulina elicit TNF-α production levels comparable to LPS at ~100× higher concentration than LPS, but without significantly increasing the risk of septic shock or deleterious pyrogenesis.     

Effect of the fungal endophyte Epichloë bromicola on polyamines in wild barley (Hordeum brevisubulatum) under salt stress

Plant and Soil - The endophytic fungus Epichloë bromicola forms mutualistic symbiotic associations with wild barley (Hordeum brevisubulatum) in the saline-alkali areas of northwestern China....     

Effect of sildenafil citrate (Viagra?) on trace element concentration in serum and brain of rats

As a vasodilator with good hemodynamic effects, sildenafil has been successfully used in the treatment of patients with pulmonary hypertension and cardiovascular diseases. By selectively inhibiting phosphodiestrase type 5 (PDE-5) and thus effectively reducing the breakdown of c GMP, sildenafil administration can markedly improve the erectile dysfunction. Sildenafil also elevates localized cerebral blood flow in rat brain. The objective of the present study was to investigate the effect of sildenafil on the level of trace elements (Zinc (Zn), copper (Cu), iron (Fe), selenium (Se), cobalt (Co), and chromium (Cr)) in blood and brain of rats. Sixteen male albino rats weighing 180-200 g were divided into two groups (8 rats/group). Sildenafil (Viagra, Pfizer Inc.) was dissolved in saline and administered at a dose of 10mg/kg i.p. (0.5 ml volume) to rats in the treated group every 72 h for 12 injections. Rats in the control group were administered the same volume of saline as in treated group. All rats were sacrificed 24h after the last injection. Blood samples were collected and serum was separated and stored at -20°C. Brains were dissected and stored frozen until analysis. Trace elements concentrations were determined by flame emission atomic absorption spectrophotometer. Results showed that sildenafil injection significantly (P<0.05) increased serum and brain Se and Cu concentrations. Moreover, sildenafil increased the Cr concentration in the brain tissue. It was concluded that sildenafil citrate administration increased serum Se and Cu as well as, increased brain Se, Cu, and Cr concentrations in rats.     

Effect of salt stress on cucumber: Na+–K+ ratio, osmolyte concentration, phenols and chlorophyll content

A pot experiment with 17 diverse genotypes of cucumber with four levels of salt stress viz., 0, 2, 4 and 6 dS m^?1 was carried out during 2006. ANOVA revealed significant differences amongst genotypes and genotype × salt stress interaction indicating the genetic variability and differential response of the genotypes to different salt stress levels. The salt stress adversely affected the biochemical parameters; effects were severe under 4 dS m^?1. No genotype could survive at 6 dS m^?1. Sodium content, Na⁺–K⁺ ratio, proline, reducing sugars, phenol and yield reduction (%) increased significantly as the salt stress increased. Potassium, chlorophyll, membrane stability index and fruit yield decreased significantly under salt stress in all genotypes. However, the genotypes CRC-8, CHC-2 and G-338 showed lower accumulation of sodium, lesser depletion of potassium, lower Na⁺–K⁺ ratio and higher accumulation of proline, reducing sugars, phenols, better membrane stability and lower yield reduction (%) under salt stress, while CH-20 and DC-1 were sensitive to salt stress. Thus, a combination of traits such as higher membrane stability, lower Na⁺–K⁺ ratio, higher osmotic concentration and selective uptake of useful ions and prevention of over accumulation of toxic ions contribute to salt stress tolerance in cucumber. These traits would be useful selection criteria during salt stress breeding in cucumber.     

Does exogenous application of 24-epibrassinolide ameliorate salt induced growth inhibition in wheat (Triticum aestivum L.)?

A greenhouse experiment was conducted to assess whether exogenously applied 24-epibrassionlide (24-epiBL) could alleviate the adverse effects of salt on wheat. Two hexaploid wheat (Triticum aestivum L.) cultivars, S-24 (salt tolerant) and MH-97 (moderately salt sensitive), were grown under control (0 mM NaCl in full strength Hoagland’s nutrient solution) or saline conditions (150 mM of NaCl in full strength Hoagland’s nutrient solution). After 41 days growth of wheat plants under saline conditions, 24-epiBL was applied as a foliar spray. Four levels of BR were used as 0 (water spray), 0.0125, 0.025, and 0.0375 mg l⁻¹. Application of 24-epiBL increased plant biomass and leaf area per plant of both cultivars under non-saline conditions. However, under saline conditions, improvement in growth due to exogenous 24-epiBL was observed only in S-24. Photosynthetic rate was reduced due to salt stress in both cultivars, but this inhibitory effect was ameliorated significantly by the exogenous application of 24-epiBL. Exogenously applied 24-epiBL also enhanced the photosystem-II efficiency in both cultivars measured as F _v /F _m ratio. Although the activities of antioxidant enzymes, Superoxide dismutase (SOD), Peroxidase (POD) and Catalase (CAT) were increased due to salt stress in both wheat cultivars, exogenously applied 24-epiBL had a varying effect on the antioxidant system. The activity of SOD remained unaffected in both cultivars due to 24-epiBL application, but that of POD and CAT was promoted in the salt stressed plants of cv. S-24 only. In conclusion, improvement in growth in both wheat cultivars due to foliar applied 24-epiBL was found to be associated with 24-epiBL-induced enhancement in photosynthetic capacity. The 24-epiBL-induced regulation of antioxidant enzymes or growth under saline conditions was cultivar specific.     

Effect of elevated CO2 on growth and crassulacean-acid-metabolism activity of Kalanchoë pinnata under tropical conditions

 Kalancho? pinnata (Lam.) Pers. (Crassulaceae), a succulent-leaved crassulacean-acid-metabolism plant, was grown in open-top chambers at ambient and elevated (two times ambient) CO₂ concentrations under natural conditions at the Smithsonian Tropical Research Institute, Republic of Panama. Nocturnal increase in titratable acidity and nocturnal carbon gain were linearly related, increased with leaf age, and were unaffected by CO₂ treatments. However, under elevated CO₂, dry matter accumulation increased by 42–51%. Thus, the increased growth at elevated CO₂ was attributable entirely to increased net CO₂ uptake during daytime in the light. Malic acid was the major organic acid accumulated overnight. Nocturnal malate accumulation exceeded nocturnal citrate accumulation by six-to eightfold at both CO₂ concentrations. Basal (predawn) starch levels were higher in leaves of plants grown at elevated CO₂ but diurnal fluctuations of starch were of similar magnitude under both ambient and elevated CO₂. In both treatments, nocturnal starch degradation accounted for between 78 and 89% of the nocturnal accumulation of malate and citrate. Glucose, fructose, and sucrose were not found to exhibit marked day-night fluctuations. Received: 4 March 1996 / Accepted: 25 May 1996     

Effect of shear stress, statins and TNF-α on hemostatic genes in human endothelial cells

Atherosclerotic plaque formation and progression are dependent on local shear stress patterns and inflammatory cytokines. Statins effectively reduce the progression of atherosclerosis and the incidence of cardiovascular events. However, the benefit of statins cannot be explained by cholesterol reduction alone. This study, investigated the non-lipid lowering effects of simvastatin and rosuvastatin on endothelial anti- and prothrombotic genes under different biomechanical and inflammatory stress conditions. Endothelial cells responded in a similar way to simvastatin and rosuvastatin. However, they were more sensitive to simvastatin. The statins had anti-inflammatory properties counteracting the TNF-α effect on the hemostatic genes studied. There was no observed synergistic effect between shear stress and simvastatin. Simvastatin had a counteracting effect on t-PA and PAI-1 compared to TNF-α and shear stress. Simvastatin blocked the TNF-α suppressive effect on thrombomodulin and eNOS, irrespective of shear stress. The strong inductive effect of TNF-α on VCAM-1 was counteracted by simvastatin and shear stress in an additive dose-response dependent way.     

Growth kinetics of 1–2 mm and 3–4 mm colonies of Nostoc sphaeroides (Cyanophyta) in outdoor culture

Nostoc sphaeroides Kützing was cultivated in paddlewheel-driven raceway ponds and the growth kinetics of 1-2 mm and 3-4 mm colonies of N. sphaeroides was studied. The biomass productivities in 2.5 m(2) raceway ponds inoculated with 1-2 mm and 3-4 mm colonies were 5.2 and 0.25 g dry wt m(-2) d(-1), respectively. Furthermore, differently sized colonies showed different relative water content, total soluble carbohydrates, chlorophyll a content and density of filaments. This is the first report on mass culture of N. sphaeroides under outdoor conditions.     

Effect of a test meal,duodenal acidification,and tetragastrin on the plasma concentration of β-endorphin-like immunoreactivity in man

The effects of various test materials on plasma β-endorphin-like immunoreactivity (β-EpLI) were investigated in man using a specific radioimmunoassay developed by the authors. Plasma β-EpLI was determined after extraction by the acid/acetone method (recovery 73±5%). The intraassay and interassay coefficients of variation were 5.0% and 7.6%, respectively. The plasma concentrations of human β-EpLI in normal subjects were 11.6±4.0 pmol/l for men (n=23) and 10.7±4.8 pmol/l for women (n=27). Ingestion of a test meal (150 g of Campbell's condensed meat soup) resulted in a biphasic rise in plasma β-EpLI from the basal level of 4.4±1.0 pmol/l to 29.2±1.9 pmol/l after 5 min and 24.8±6.7 pmol/l after 90 min. Intraduodenal infusion of 115 ml of 0.1 M HCl over 10 min increased the plasma β-EpLI level from 8.7±0.5 pmol/l to 15.5±0.4 pmol/l at 10 min after the start of infusion, but the level rapidly returned to the initial value after the end of the infusion. Intramuscular injection of 4 μg/kg body weight of tetragastrin markedly stimulated gastric acid output and β-EpLI release, but pretreatment with 10 mg of histamine H₂ receptor antagonist inhibited the gastric acid output and plasma β-EpLI release induced by tetragastrin.These results indicate that β-EpLI release is stimulated by ingestion of meat soup, duodenal acidification and tetragastrin administration. It is suggested that gastric acid participates, at least in part, in postprandial release of β-EpLI, probably from the gastrointestinal tract.     

Effect of salinity on seed germination,growth and ion content in dimorphic seeds of Salicornia europaea L.(Chenopodiaceae)

The halophyte Salicornia europaea L. is a widely distributed salt-tolerant plant species that produces numerous dimorphic seeds. We studied germination and recovery in dimorphic seeds of Central Asian S. europaea under various salinity conditions. We also tested the effects of various salts on Natand Ktaccumulation during plant development from germination to anthesis under greenhouse conditions. We found good germination（close to control） of large seeds under Na Cl between 0.5 and 2%, Na₂SO₄and 2 Na Cl t KCl t Ca Cl between 0.5 and 3%, and 2Na₂SO₄t K₂SO₄t Mg SO4 between 0.5 and 5%. For the small seeds, we found stimulating effects of chloride salts（both pure and mixed） under 0.5e1% concentrations, and sulfate salts under 0.5e3%. Both types of seeds showed high germination recovery potential. Salt tolerance limits of the two seed types during germination and at the later stages of development were very similar（4e5%）. During plant growth the optimal concentrations of mixed chloride and sulfate salts ranged from 0.5 to 2%. The mechanisms of salt tolerance in the two seed types of S. europaea appear to differ, but complement each other, improving overall adaptation of this species to high salinity.     

Effect of ploidy levels on the activities of Δ1-pyrroline-5-carboxylate synthetase,superoxide dismutase and peroxidase in Cenchrus species grown under water stress

The effects of ploidy levels on the activities of Δ¹-pyrroline-5-carboxylate synthetase (P5CS; EC not assigned), superoxide dismutase (SOD; EC 1.15.1.1) and guaiacol peroxidase (POX; EC 1.11.1.7), as well as malondialdehyde (MDA) and proline contents were studied in two months old plants of Cenchrus species. The Cenchrus species represent three ploidy levels: diploid, tetraploid, hexaploid and two life spans: annual and perennial. Plants were subjected to water stress for 2, 4, 6 and 8 d by withholding water under glasshouse conditions. Although the levels of proline increased with the magnitude of water stress, the P5CS activity did not show a corresponding increase in all species. Peroxidase and superoxide dismutase activities showed an increase or steady state in the early phase of drought and then declined with the further increase in the magnitude of water stress, indicating differing behaviors of species towards drought tolerance. Under drought, diploid Cenchrus species had a higher POX activity, MDA accumulation and lower proline content than tetraploid species. Lower POX and higher P5CS activities and proline contents, however, were observed in hexaploid and tetraploid species. Taken together, our findings suggest that diploid species have a less efficient antioxidant system to scavenge reactive oxygen species than tetra and hexaploid Cenchrus. This may result in a corresponding variability in growth and persistence under natural grasslands. The study also paves the way for investigations on the molecular events associated with drought in Cenchrus species differing in ploidy and life span.     

Effect of short and long periods of separation on agonistic behaviour,injuries and stress in Hérens cows kept in loose housing

Hérens cows are typically not dehorned and are therefore housed in tie-barns during winter. Recently, however, farmers have started to also use loose housing systems. They separate single cows from their herd for periods of a few days to ensure undisturbed calving and to avoid excessive activity caused by animals in oestrus. As these cows are highly motivated to fight, the re-introduction of individuals after separation is usually associated with increased agonistic behaviour. The aim of this study was to compare the effects of the length of separation with regard to behaviour, injuries and stress response.The study was conducted with 45 focal horned Hérens cows kept in four groups of 10, 20, 18 and 21 cows respectively on two Swiss farms: two groups were kept as suckler cows and two groups as dairy cows. Each focal cow was separated on two occasions, once for a short (median: 1 day; high oestrus in dairy, late pregnancy or lactation in suckler cows) and once for a longer (median: 2 days; high oestrus in dairy, calving in suckler cows) period. During the 6 h following the re-introduction, agonistic behaviour was recorded. Occurrence of fresh wounds was noted 10 h after re-introduction. As an indicator of physiological stress, faecal samples were collected and concentrations of the cortisol metabolite 11,17-dioxoandrostanes (11,17-DOA) were determined. All data were analysed using generalised linear mixed-effects models.Frequency and duration of agonistic interaction increased with longer separation (p < 0.02) and quickly decreased during the hours following the re-introduction of the focal cow (p < 0.001). The risk of injuries did not significantly change with duration of separation. Separating the cow from her group brought about an increase in concentration of 11,17-DOA (p = 0.012) that decreased over time (p < 0.001). Interestingly, concentrations during the re-introduction phase were lower in comparison with the separation phase (p < 0.001). The concentration of 11,17-DOA was lower during the longer separations (p = 0.018). We did not find any difference of practical importance in how cows reacted to long compared to the short separation related to the different hormonal states of dairy and suckler cows during separation, nor related to the changes in hormonal state within the suckler cows.In conclusion, the duration of a separation of a single Hérens cow from her herd should be minimised so as to reduce negative effects resulting from agonistic interactions.