Seed priming with potassium nitrate alleviates the high temperature stress by modulating growth and antioxidant potential in carrot seeds and seedlings.

Early season carrot (Daucus carota) production is being practiced in Punjab, Pakistan to meet the market demand but high temperature hampers the seed germination and seedling establishment which cause marked yield reduction. Seed priming with potassium nitrate breaks the seed dormancy and improves the seed germination and seedling growth potential but effects vary among the species and ecological conditions. The mechanism of KNO3 priming in high temperature stress tolerance is poorly understood yet. Thus, present study aimed to evaluate high temperature stress tolerance potential of carrot seeds primed with potassium nitrate and impacts on growth, physiological, and antioxidant defense systems. Carrot seeds of a local cultivar (T-29) were primed with various concentration of KNO3 (T0: unprimed (negative control), T1: hydroprimed (positive control), T2: 50 mM, T3:100mM, T4: 150 mM, T5: 200 mM, T6: 250 mM and T7: 300 mM) for 12 h each in darkness at 20 ± 2℃. Seed priming with 50 mM of KNO3 significantly enhanced the seed germination (36%), seedling growth (28%) with maximum seedling vigor (55%) and also exhibited 16.75% more carrot root biomass under high temperature stress as compared to respective control. Moreover, enzymatic activities including peroxidase, catalase, superoxidase dismutase, total phenolic contents, total antioxidants contents and physiological responses of plants were also improved in response to seed priming under high temperature stress. By increasing the level of KNO3, seed germination, growth and root biomass were reduced. These findings suggest that seed priming with 50 mM of KNO3 can be an effective strategy to improve germination, growth and yield of carrot cultivar (T-29) under high temperature stress in early cropping. This study also proposes that KNO3 may induces the stress memory by heritable modulations in chromosomal structure and methylation and acetylation of histones that may upregulate the hormonal and antioxidant activities to enhance the stress tolerance in plants.

Potassium ferrate's disinfecting ability: a study on human adenovirus, Giardia duodenalis, and microbial indicators under varying pH and water temperature conditions.

Ferrate (Fe(VI): HFeO4- /FeO42-), a potent oxidant, has been investigated as an alternative chemical disinfectant in water treatment due to its reduced production of disinfection by-products. In this study, we assessed the disinfecting ability of potassium ferrate against a variety of microorganisms, including waterborne pathogens, under varying pH and water temperature conditions. We presented CT values, a metric of ferrate concentrations (C) and contact time (T), to quantify microbial inactivation rates. Among the tested microorganisms, human adenovirus was the least resistant to ferrate, followed by waterborne bacteria such as Escherichia coli and Vibrio cholerae, and finally, the protozoan parasite Giardia duodenalis. We further investigated the impact of two pH values (7 and 8) and two temperatures (5 and 25 °C) on microbial inactivation rates, observing that inactivation rates increased with lower pH and higher temperature. In addition to showcasing ferrate's capacity to effectively inactivate a range of the tested microorganisms, we offer a ferrate CT table to facilitate the comparison of the effectiveness of various disinfection methods.

Metabolic activities and molecular investigations of the ameliorative impact of some growth biostimulators on chilling-stressed coriander (Coriandrum sativum L.) plant.

BACKGROUND: Priming of seed prior chilling is regarded as one of the methods to promote seeds germination, whole plant growth, and yield components. The application of biostimulants was reported as beneficial for protecting many plants from biotic or abiotic stresses. Their value was as important to be involved in improving the growth parameters of plants. Also, they were practiced in the regulation of various metabolic pathways to enhance acclimation and tolerance in coriander against chilling stress. To our knowledge, little is deciphered about the molecular mechanisms underpinning the ameliorative impact of biostimulants in the context of understanding the link and overlap between improved morphological characters, induced metabolic processes, and upregulated gene expression. In this study, the ameliorative effect(s) of potassium silicate, HA, and gamma radiation on acclimation of coriander to tolerate chilling stress was evaluated by integrating the data of growth, yield, physiological and molecular aspects. RESULTS: Plant growth, yield components, and metabolic activities were generally diminished in chilling-stressed coriander plants. On the other hand, levels of ABA and soluble sugars were increased. Alleviation treatment by humic acid, followed by silicate and gamma irradiation, has notably promoted plant growth parameters and yield components in chilling-stressed coriander plants. This improvement was concomitant with a significant increase in phytohormones, photosynthetic pigments, carbohydrate contents, antioxidants defense system, and induction of large subunit of RuBisCO enzyme production. The assembly of Toc complex subunits was maintained, and even their expression was stimulated (especially Toc75 and Toc 34) upon alleviation of the chilling stress by applied biostimulators. Collectively, humic acid was the best the element to alleviate the adverse effects of chilling stress on growth and productivity of coriander. CONCLUSIONS: It could be suggested that the inducing effect of the pretreatments on hormonal balance triggered an increase in IAA + GA3/ABA hormonal ratio. This ratio could be linked and engaged with the protection of cellular metabolic activities from chilling injury against the whole plant life cycle. Therefore, it was speculated that seed priming in humic acid is a powerful technique that can benefit the chilled along with non-chilled plants and sustain the economic importance of coriander plant productivity.

Biochemical and physiological impacts of zinc sulphate, potassium phosphite and hydrogen sulphide in mitigating stress conditions in soybean.

Soybean is the most widely grown oilseed in the world. It is an important source of protein and oil which are derived from its seeds. Drought stress is a major constraint to soybean yields. Finding alternative methods to mitigate the water stress for soybean is useful to maintain adequate crop yields. The aim of this study was to evaluate the morpho-physiological, biochemical and metabolic changes in soybean plants in two ontogenetic stages, under exposure to water deficit and treatment with zinc sulphate (ZS), potassium phosphite (PP) or hydrogen sulphide (HS). We carried out two independent experiments in the V4 and R1 development stages consisting of the following treatments: well-watered control (WW, 100% maximum water holding capacity, MWHC), water deficit (WD, 50% MWHC), PP + WW, PP + WD, HS + WW, HS + WD, ZS + WW and ZS + WD. The experimental design consisted of randomized blocks with eight treatments with five replicates. Morphological, physiological and metabolic analyses were performed 8 days after the start of the treatments for both experiments. We identified two tolerance mechanisms acting in response to compound application during water stress: the first involved the upregulation of antioxidant enzyme activity and the second involved the accumulation of soluble sugars, free amino acids and proline to facilitate osmotic adjustment. Both mechanisms are related to the maintenance of the photosynthetic parameters and cell membrane integrity. This report suggests the potential agricultural use of these compounds to mitigate drought effects in soybean plants.

Potassium dihydrogen phosphate promotes the proliferation and differentiation of human periodontal ligament stem cells via nuclear factor kappa B pathway.

INTRODUCTION: Periodontal ligament stem cells (PDLSCs) are vital for the regeneration of periodontal tissues. Potassium dihydrogen phosphate (KH2PO4) has recently been applied as a component of the mineralization inducing medium (MM), which can be used to induce osteogenic differentiation of dental stem cells. However, whether KH2PO4 has effects on PDLSCs has not been studied. MATERIALS AND METHODS: PDLSCs were isolated by magnetic activated cell sorting and cultured. Alkaline phosphatase (ALP) activity and ALP protein expression of PDLSCs treated with different concentrations of KH2PO4 were examined to make sure the optimal concentration of KH2PO4 for the following experiments. The effects of KH2PO4 on the proliferation and differentiation of PDLSCs were investigated by flow cytometry, cell counting kit-8 assay, alizarin red staining, real-time RT-PCR, and Western blot. The involvement of nuclear factor kappa B (NF-κB) pathway in KH2PO4-treated PDLSCs was analyzed by Western blot and alizarin red staining. RESULTS: ALP activity assay and ALP protein expression examination revealed that 1.8 mmol/L KH2PO4 was the optimal concentration for the induction of hPDLSCs by KH2PO4. The proliferation and mineralization capacity of PDLSCs treated with KH2PO4 were enhanced as compared with the control group. PDLSCs treated with KH2PO4 showed an improved proliferation capacity in logarithmic growth phase at day 7. As PDLSCs were treated with KH2PO4, the expression of odonto/osteogenic markers (OCN/OCN, DSP/DSPP, OSX/OSX, RUNX2/RUNX2, and ALP/ALP) in cells were up-regulated at day 3 or 7. Moreover, the expression of IκBα in cytoplasm was down-regulated, along with an increased expression of p-P65 in cytoplasm and an up-regulated expression of P65 in nucleus. When treated with BMS345541 (the specific NF-κB inhibitor), the odonto/osteogenic differentiation of KH2PO4-treated PDLSCs was significantly attenuated. CONCLUSION: KH2PO4 can improve the proliferation and odonto/osteogenic differentiation capacity of PDLSCs via NF-κB pathway, and thus represents a potential target involved in the regeneration of periodontium for clinical treatments.

Enhanced Cycling Performance of Rechargeable Zinc-Air Flow Batteries Using Potassium Persulfate as Electrolyte Additive.

Zinc-air batteries (ZABs) offer high specific energy and low-cost production. However, rechargeable ZABs suffer from a limited cycle life. This paper reports that potassium persulfate (KPS) additive in an alkaline electrolyte can effectively enhance the performance and electrochemical characteristics of rechargeable zinc-air flow batteries (ZAFBs). Introducing redox additives into electrolytes is an effective approach to promote battery performance. With the addition of 450 ppm KPS, remarkable improvement in anodic currents corresponding to zinc (Zn) dissolution and limited passivation of the Zn surface is observed, thus indicating its strong effect on the redox reaction of Zn. Besides, the addition of 450 ppm KPS reduces the corrosion rate of Zn, enhances surface reactions and decreases the solution resistance. However, excess KPS (900 and 1350 ppm) has a negative effect on rechargeable ZAFBs, which leads to a shorter cycle life and poor cyclability. The rechargeable ZAFB, using 450 ppm KPS, exhibits a highly stable charge/discharge voltage for 800 cycles. Overall, KPS demonstrates great promise for the enhancement of the charge/discharge performance of rechargeable ZABs.

Comparative Analysis of the Effect of Inorganic and Organic Chemicals with Silver Nanoparticles on Soybean under Flooding Stress.

Extensive utilization of silver nanoparticles (NPs) in agricultural products results in their interaction with other chemicals in the environment. To study the combined effects of silver NPs with nicotinic acid and potassium nitrate (KNO3), a gel-free/label-free proteomic technique was used. Root length/weight and hypocotyl length/weight of soybean were enhanced by silver NPs mixed with nicotinic acid and KNO3. Out of a total 6340 identified proteins, 351 proteins were significantly changed, out of which 247 and 104 proteins increased and decreased, respectively. Differentially changed proteins were predominantly associated with protein degradation and synthesis according to the functional categorization. Protein-degradation-related proteins mainly consisted of the proteasome degradation pathway. The cell death was significantly higher in the root tips of soybean under the combined treatment compared to flooding stress. Accumulation of calnexin/calreticulin and glycoproteins was significantly increased under flooding with silver NPs, nicotinic acid, and KNO3. Growth of soybean seedlings with silver NPs, nicotinic acid, and KNO3 was improved under flooding stress. These results suggest that the combined mixture of silver NPs, nicotinic acid, and KNO3 causes positive effects on soybean seedling by regulating the protein quality control for the mis-folded proteins in the endoplasmic reticulum. Therefore, it might improve the growth of soybean under flooding stress.

Effect of Interaction between 17ß-Estradiol, 2-Methoxyestradiol and 16α-Hydroxyestrone with Chromium (VI) on Ovary Cancer Line SKOV-3: Preliminary Study.

Ovarian cancer is the leading cause of death from gynecologic malignancies. Some estrogens, as well as xenoestrogens, such as chromium (VI) (Cr(VI)), are indicated as important pathogenic agents. The objective of this study was to evaluate the role of estradiol and some its metabolites upon exposure to the metalloestrogen Cr(VI) in an in vitro model. The changes in cell viability of malignant ovarian cancer cells (SKOV-3 resistant to cisplatin) exposed to 17ß-estradiol (E2) and its two metabolites, 2-methoxyestradiol (2-MeOE2) and 16α-hydroxyestrone (16α-OHE1), upon exposure to potassium chromate (VI) and its interactions were examined. The single and mixed models of action, during short and long times of incubation with estrogens, were applied. The different effects (synergism and antagonism) of estrogens on cell viability in the presence of Cr(VI) was observed. E2 and 16α-OHE1 caused a synergistic effect after exposure to Cr(VI). 2-MeOE2 showed an antagonistic effect on Cr(VI). The examined estrogens could be ranked according to the most protective effect or least toxicity in the order: 2-MeOE2 > E2 > 16α-OHE1. Early pre-incubation (24 h or 7 days) of cells with estrogens caused mostly an antagonistic effect-protective against the toxic action of Cr(VI). The beneficial action of estrogens on the toxic effect of Cr(VI), in the context of the risk of ovarian cancer, seems to be important and further studies are needed.

Potassium Stimulation of IAA Transport Mediated by the Arabidopsis Importer AUX1 Investigated in a Heterologous Yeast System.

Auxin regulates diverse processes involved in plant growth and development. AUX1 is the first identified and most widely investigated auxin importer, and plays an important role in root gravitropism and the development of lateral root and root hair. However, the regulation of auxin transport by AUX1 is still not well understood. In this study, we examined the effect of metal ions on AUX1 transport function and found that the activity could be specifically stimulated four times by K+. Further experiments revealed the preference of KF on the enhancement of transport activity of AUX1 over KCl, KBr, and KI. In addition, the interaction between K+ and AUX1 confers AUX1 more resistant to thermal stress but more vulnerable to proteolysis. Conventional chemical modification indicated that the extracellular acidic amino acids of AUX1 play a key role in the K+ stimulation. Site-specific mutagenesis showed that the replacement of Asp166, Asp293, and Asp312 of AUX1 to alanine deteriorated the K+-stimulated auxin transport. By contrast, when these residues were mutated to glutamate, lysine, or asparagine, only the D312E variant restored the IAA transport activity to the wild-type level. It is thus convinced that D312 is presumably the most promising residue for the K+ stimulation on AUX1.

The negative effect of unloading exceeds the bone-sparing effect of alkaline supplementation: a bed rest study.

Potassium bicarbonate was administrated to an already alkaline diet in seven male subjects during a 21-day bed rest study and was able to decrease bed rest induced increased calcium excretion but failed to prevent bed rest-induced bone resorption. INTRODUCTION: Supplementation with alkali salts appears to positively influence calcium and bone metabolism and, thus, could be a countermeasure for population groups with an increased risk for bone loss. However, the extent to which alkalization counteracts acid-induced bone resorption or whether it merely has a calcium and bone maintenance effect is still not completely understood. In the present study, we hypothesized that additional alkalization to an already alkaline diet can further counteract bed rest-induced bone loss. METHODS: Seven healthy male subjects completed two parts of a crossover designed 21-day bed rest study: bed rest only (control) and bed rest supplemented with 90 mmol potassium bicarbonate (KHCO3) daily. RESULTS: KHCO3supplementation during bed rest resulted in a more alkaline status compared to the control intervention, demonstrated by the increase in pH and buffer capacity level (pH p = 0.023, HCO3p = 0.02, ABE p = 0.03). Urinary calcium excretion was decreased during KHCO3 supplementation (control 6.05 ± 2.74 mmol/24 h; KHCO3 4.87 ± 2.21 mmol/24 h, p = 0.03); whereas, bone formation was not affected by additional alkalization (bAP p = 0.58; PINP p = 0.60). Bone resorption marker UCTX tended to be lower during alkaline supplementation (UCTX p = 0.16). CONCLUSIONS: The more alkaline acid-base status, achieved by KHCO3 supplementation, reduced renal calcium excretion during bed rest, but was not able to prevent immobilization-induced bone resorption. However, advantages of alkaline salts on bone metabolism may occur under acidic metabolic conditions or with respect to the positive effect of reduced calcium excretion within a longer time frame. TRIAL REGISTRATION: Trial number: NCT01509456.

Acute interaction between oral glucose (75 g as Lucozade) and inorganic nitrate: Decreased insulin clearance, but lack of blood pressure-lowering.

AIMS: Dietary inorganic nitrate (NO3- ) lowers peripheral blood pressure (BP) in healthy volunteers, but lacks such effect in individuals with, or at risk of, type 2 diabetes mellitus (T2DM). Whilst this is commonly assumed to be a consequence of chronic hyperglycaemia/hyperinsulinaemia, we hypothesized that acute physiological elevations in plasma [glucose]/[insulin] blunt the haemodynamic responses to NO3- , a pertinent question for carbohydrate-rich Western diets. METHODS: We conducted an acute, randomized, placebo-controlled, double-blind, crossover study on the haemodynamic and metabolic effects of potassium nitrate (8 or 24 mmol KNO3 ) vs. potassium chloride (KCl; placebo) administered 1 hour prior to an oral glucose tolerance test in 33 healthy volunteers. RESULTS: Compared to placebo, there were no significant differences in systolic or diastolic BP (P = 0.27 and P = 0.30 on ANOVA, respectively) with KNO3 , nor in pulse wave velocity or central systolic BP (P = 0.99 and P = 0.54 on ANOVA, respectively). Whilst there were significant elevations from baseline for plasma [glucose] and [C-peptide], no differences between interventions were observed. A significant increase in plasma [insulin] was observed with KNO3 vs. KCl (n = 33; P = 0.014 on ANOVA) with the effect driven by the high-dose cohort (24 mmol, n = 13; P < 0.001 on ANOVA; at T = 0.75 h mean difference 210.4 pmol/L (95% CI 28.5 to 392.3), P = 0.012). CONCLUSIONS: In healthy adults, acute physiological elevations of plasma [glucose] and [insulin] result in a lack of BP-lowering with dietary nitrate. The increase in plasma [insulin] without a corresponding change in [C-peptide] or [glucose] suggests that high-dose NO3- decreases insulin clearance. A likely mechanism is via NO-dependent inhibition of insulin-degrading enzyme.

Inhibition of dentin matrix-bound cysteine cathepsins by potassium fluoride.

Matrix metalloproteinases (MMPs) and cysteine cathepsins (CCs) can break down unprotected type I collagen fibrils in dentin matrix. This study investigated the use of potassium fluoride (KF) as a potential inhibitor of MMPs and CCs in dentin. Demineralized dentin beams were divided into groups (n = 10 in each group) and incubated in artificial saliva (AS, control), either alone or with one of seven concentrations of KF (6-238 mM fluoride) for 1, 7, and 21 d. After 21 d, all groups were further aged in AS for 6 months. Total MMP activity was screened using the colorimetric MMP assay. The activities of MMP-2 and MMP-9 were investigated using gelatin zymography. At the end of each incubation, changes in loss of dry mass and CC-mediated or total dissolution of collagen peptides were measured via precision weighing, C-terminal crosslinked telopeptide of type I collagen (CTX), and hydroxyproline (HYP) assays. The beams were examined using scanning electron microscopy. After 21 d, total MMP activities, dry mass loss, and CTX release for the groups exposed to 179 and 238 mM fluoride were significantly lower compared with the control group. After 6 months, all groups showed similar total MMP activity, dry mass loss, and HYP release, and CTX levels were significantly lower when the fluoride concentration was ≥24 mM. Calcium fluoride (CaF2 )-like precipitates were observed over the beams. In summary, KF significantly inhibited the catalytic activity of dentin matrix-bound CCs but did not seem to be effective for MMP-mediated activity.

Production of mouse fetuses using spermatozoa exposed temporarily to high temperature or continuously to room temperature after freeze-drying in Na+-free/K+-rich EGTA buffer.

Present study aimed to determine to what extent freeze-dried spermatozoa were able to withstand high-temperature conditions: transient increase in storage temperature and long-term exposure to room temperature. Mouse spermatozoa were freeze-dried in EGTA/Tris-HCl buffered solution alkalinized using KOH (K-ETBS, pH 7.7), and then stored for up to 7 months at 4 °C or 25 °C. After 2 months' storage, some of the 4°C-stored spermatozoa were exposed to 40 °C for 1 week or 1 month, then again stored at 4 °C for the remaining storage period. Following storage, rehydrated spermatozoa were injected into mouse oocytes. The resulting zygotes were assessed for chromosome damage, in vitro development up to the blastocyst stage, and post-implantation development to normal fetuses on day 18 of gestation. In storage at 4 °C, one-week exposure to 40 °C had no adverse effect on the chromosome integrity and developmental competence compared to non-exposure to 40 °C (continuous storage at 4 °C). In contrast, one-month exposure to 40 °C caused an increasing level of chromosome damage (36%, P < 0.05) and reduced frequencies of blastocysts (54%, P < 0.05) and normal fetuses (36%, P < 0.05) compared to the frequencies obtained by continuous storage at 4 °C (15%, 82% and 52%, respectively). Storage at 25 °C resulted in accumulation of chromosome damage (27%, P < 0.05), leading to decreased blastocyst formation (63%, P < 0.05). But, the frequency of normal fetus (44%) was not significantly different from that obtained by continuous storage at 4 °C. Consequently, mouse spermatozoa freeze-dried in K-ETBS withstood temporary exposure to 40 °C for 1 week. Chromosome damage accumulated in spermatozoa during storage at 25 °C.

Use of Potassium Hydroxide (KOH) Test Reduces Antifungal Medication Prescription for Suspected Monilial Diaper Dermatitis in the Neonatal Intensive Care Unit: A Quality Improvement Project.

BACKGROUND: Despite availability of rapid fungal potassium hydroxide (KOH) tests, many care providers rely on visual assessment to determine the diagnosis of monilial diaper dermatitis (MDD). PURPOSE: To determine whether a KOH test, when MDD is suspected, would result in more accurate diagnoses, with decreased antifungal medication prescription and exposure. METHODS: Quality improvement project from 2016 through 2017 with protocol implemented in 2017 for treatment of MDD after positive KOH testing. If monilial rash suspected, after 2 negative KOH tests, then antifungal ordered (considered false negative). χ testing and cost determination were performed. SAMPLE: Neonates in 2 level III neonatal intensive care units. OUTCOME VARIABLES: KOH test results, use of antifungal medication, and cost. RESULTS: The patient census included 1051 and 1015 patients in the year before and after the protocol initiation. The medical orders for antifungal medication decreased from 143 to 36 (P < .001; 95% odds ratio confidence interval, 2.24-4.38). There was a 75% reduction in both use and cost, as charged, of antifungal agents. Overall charges, including KOH test costs, decreased by 12%. Three infants received multiple negative KOH tests, then a positive one. These met the definition of false-negative tests, per protocol. There were no cases of fungal sepsis. IMPLICATIONS FOR PRACTICE: Use of a quality improvement protocol, in which the use of KOH testing is required, before antifungal agents are prescribed, results in decreased exposure and costs. IMPLICATIONS FOR RESEARCH: To test the feasibility of bedside "point-of-care" KOH testing, and whether KOH testing and reduced antifungal medication use affects antimicrobial resistance or invasive fungal sepsis.

Identification and quantification of protein S-nitrosation by nitrite in the mouse heart during ischemia.

Nitrate (NO3-) and nitrite (NO2-) are known to be cardioprotective and to alter energy metabolism in vivo NO3- action results from its conversion to NO2- by salivary bacteria, but the mechanism(s) by which NO2- affects metabolism remains obscure. NO2- may act by S-nitrosating protein thiols, thereby altering protein activity. But how this occurs, and the functional importance of S-nitrosation sites across the mammalian proteome, remain largely uncharacterized. Here we analyzed protein thiols within mouse hearts in vivo using quantitative proteomics to determine S-nitrosation site occupancy. We extended the thiol-redox proteomic technique, isotope-coded affinity tag labeling, to quantify the extent of NO2--dependent S-nitrosation of proteins thiols in vivo Using this approach, called SNOxICAT (S-nitrosothiol redox isotope-coded affinity tag), we found that exposure to NO2- under normoxic conditions or exposure to ischemia alone results in minimal S-nitrosation of protein thiols. However, exposure to NO2- in conjunction with ischemia led to extensive S-nitrosation of protein thiols across all cellular compartments. Several mitochondrial protein thiols exposed to the mitochondrial matrix were selectively S-nitrosated under these conditions, potentially contributing to the beneficial effects of NO2- on mitochondrial metabolism. The permeability of the mitochondrial inner membrane to HNO2, but not to NO2-, combined with the lack of S-nitrosation during anoxia alone or by NO2- during normoxia places constraints on how S-nitrosation occurs in vivo and on its mechanisms of cardioprotection and modulation of energy metabolism. Quantifying S-nitrosated protein thiols now allows determination of modified cysteines across the proteome and identification of those most likely responsible for the functional consequences of NO2- exposure.

GsSLAH3, a Glycine soja slow type anion channel homolog, positively modulates plant bicarbonate stress tolerance.

Alkaline stress is a major form of abiotic stress that severely inhibits plant growth and development, thus restricting crop productivity. However, little is known about how plants respond to alkali. In this study, a slow-type anion channel homolog 3 gene, GsSLAH3, was isolated and functionally characterized. Bioinformatics analysis showed that the GsSLAH3 protein contains 10 transmembrane helices. Consistently, GsSLAH3 was found to locate on plasma membrane by transient expression in onion epidermal cells. In wild soybeans, GsSLAH3 expression was induced by NaHCO3 treatment, suggesting its involvement in plant response to alkaline stress. Ectopic expression of GsSLAH3 in yeast increased sensitivity to alkali treatment. Dramatically, overexpression of GsSLAH3 in Arabidopsis thaliana enhanced alkaline tolerance during the germination, seedling and adult stages. More interestingly, we found that transgenic lines also improved plant tolerance to KHCO3 rather than high pH treatment. A nitrate content analysis of Arabidopsis shoots showed that GsSLAH3 overexpressing lines accumulated more NO3- than wild-type. In summary, our data suggest that GsSLAH3 is a positive alkali responsive gene that increases bicarbonate resistance specifically.

Effect of nitrogen sources on gene expression of Stevia rebaudiana (Bertoni) under in vitro conditions.

Stevia rebaudiana (Bertoni) is a non-caloric sweetener belonging to Asteraceae family. Stevia compounds such as steviol glycosides (SGs) are 200 times sweeter than sugar. Stevioside and rebaudioside A are the two major steviol glycosides. Nitrogen is an essential element for plant growth and development. In this study the effects of nitrogen influenced by different concentrations of NH4NO3 (0, 825 and 1650 mg/l) and KNO3 (0, 950 and 1900 mg/l) is examined in MS medium. To analysis the UGT74G1 and UGT76G1 genes expression, involved in the synthesis of SGs, RT-qPCR technique was performed. Data showed that there were significant differences between all media. The shoot length, seedlings dry weight and leaf fresh weight of stevia increased with applying NH4NO3 along with KNO3. The highest expression of UGT74G1 gene, was observed in plantlets grown on MS medium with 0 mg/l NH4NO3 and 950 mg/l KNO3 (1.291 total lab unit) but the highest expression of UGT76G1 gene, was observed in plantlets grown on MS medium added by 1650 mg/l NH4NO3 +950 mg/l KNO3 (1.08 total lab unit). Moreover, the lowest value of UGT74G1 gene expression were revealed in MS medium added by 1650 mg/l NH4NO3 +0 mg/l KNO3 (0.80 total lab unit) and the lowest values of UGT76G1 gene expression seen in MS medium with 0 mg/l NH4NO3 +950 mg/l KNO3 (0.85 total lab unit) concentrations. The results of this study could be valuable in stevia breeding programs through glycosides biosynthesis pathways.

Optimized 1,3-propanediol production from crude glycerol using mixed cultures in batch and continuous reactors.

The production of 1,3-propanediol from crude glycerol and mixed anaerobic sludge was investigated in batch experiments and continuous reactors. Using a 23 complete factorial design, the effects of the concentration of glycerol (22-30 g L-1), KH2PO4 (1.50-2.00 g L-1), and vitamin B12 (7-8 mg L-1) were examined in batch reactors. As an evaluated response, the highest 1,3-PD yields occurred for high concentrations of vitamin B12 and low levels of KH2PO4, reaching 0.57 g g-1 glycerol consumed. The variable glycerol concentration was not significant in the studied range. In addition, the condition that provided the best 1,3-PD yield was applied to an anaerobic fluidized bed reactor fed with crude glycerol (26.0 g L-1), which was monitored as the hydraulic retention time (HRT) decreased from 36 to 12 h. The greatest 1,3-PD yield, of 0.31 g g-1 glycerol, was obtained with an HRT of 28 h.

NaK alloy-induced in vivo tumor ablation therapy.

PURPOSE: Alkali metal ablation is newly emerging as an effective, economic and minimally invasive ablation therapy. This study is dedicated to demonstrate the high efficiency of NaK alloy ablation on in vivo tumors with different stages in mice. MATERIAL AND METHODS: Panc02 tumor cells were injected into 21 female C57B/L mice, which were divided into three groups. Two experimental groups of mice received the same percutaneous NaK alloy injection for a week apart. The inner temperature response and surface temperature distribution were measured using a thermal couple and an infrared camera. After each ablation experiment, two mice in each group were chosen randomly to make pathological sections. The tumor volumes were measured once every two days. At the end, all tumors were cut off to calculate the tumor inhibition rates. RESULTS: The NaK alloy-induced ablation therapy produced an obvious temperature increase (85 °C) in the ablation region and the high temperature distribution was relatively concentrated. The histopathology sections showed that developing stage tumors received incomplete destruction of the malignant cells compared with early stage tumors. The tumor inhibition rate in the early and developing tumor treatment groups were 88.5% and 67.6%, respectively. CONCLUSIONS: This technology provides a nearly thorough ablation treatment for early stage tumors and also a palliative treatment for developing tumors.

Protective Role of Nitrate/Nitrite Reductase System during Transient Global Cerebral Ischemia.

The effects of a non-selective blocker of NO synthases LNNA in a dose of 25 mg/kg and nitrates KNO3, NaNO3, Mg(NO3)2, and Ca(NO3)2 in doses of 5 and 50 mg/kg were studied on the model of experimental ischemic stroke induced by bilateral occlusion of the common carotid arteries. Wistar rats were randomized into 40 treatment (n=960) and 8 control (n=192) groups. Treatment group rats received injection of either nitrate, or LNNA, or a combination LNNA+nitrate. All substances were administered intraperitoneally 1 h prior to brain ischemia or 5 sec after occlusion of the common carotid arteries. Control rats received the same volume of 0.9% NaCl at the same terms. The non-selective inhibitor of NO synthases LNNA administered against the background of brain ischemia increased neurological deficit and animal mortality. Nitrate/nitrite reductase system had protective properties depending on the cation of nitrate and concentration of a nitrate during inhibition of NO synthase system under conditions of brain ischemia and hypoxia.