Supportive effect of naringenin on NaCl-induced toxicity in Carthamus tinctorius seedlings.

In the present study, we used exogenous naringenin (0.5 mM) pretreatment before the stress (25 mM NaCl) on the growth and tolerance of safflower seedlings under non-salinity conditions and salinity conditions. Our results showed that salinity treatment significantly declined the biomass, leaf relative water content, chlorophyll content, K+ content, and K+/Na+ ratio by 28%, 28%, 12%, 36%, and 56%, respectively, as compared to untreated control. The results obtained in the present study showed the beneficial effects of the pretreatment of naringenin in safflower seedlings under non-salinity conditions concerning increasing plant biomass, total phenolic compound, radical scavenging activity (RSA), soluble sugar content, proline, glutathione, enzymatic antioxidants, and K+ content. Nevertheless, naringenin pretreated plants showed a clear increment in the values of biomass, RSA, total phenolic compound, and catalase enzyme activity parameters under salinity stress. Salinity stress caused ionic phytotoxicity and oxidative stress by enhancing Na+ content, H2O2 accumulation, malondialdehyde (MDA), and antioxidants. However, naringenin alleviated salt-induced oxidative stress by decreasing H2O2 and MDA content in the leaves and improving the catalase activity in treated plants. Generally, it could be concluded pretreatment of naringenin before stress could partly diminish NaCl-caused oxidative stress in safflower seedlings, probably due to improvement in enzymatic and non-enzymatic antioxidants and reduced cell membrane damage.

We report for the first time that applying exogenous naringenin pretreatment before the stress could improve growth and diminish NaCl-caused oxidative stress in safflower seedlings, probably due to the improvement in enzymatic and non-enzymatic antioxidants and reduced cell membrane damage. This implies that applying exogenous naringenin pretreatment before the stress is a promising approach for sustainable crop production under salinity stress.

Foliar spray of commercial seaweed and amino acid-derived biostimulants promoted phytoremediation potential and salinity stress tolerance in halophytic grass, Puccinellia distans.

Plants pretreatment with various chemicals has often been used to diminish salinity stress impact on plants. An experiment was carried out to determine the effect of foliar spray of two commercially available biostimulants (Algabon® [0.5 g/l] and Bonamid® [2 g/l]) on the growth and tolerance of halophytic grass, Pucccinellia distans under non-salinity condition (NSC) and salinity condition (SC). The greenhouse experiment was set up in a completely randomized design with three treatments repeated three times. Our results showed that biomass, leaf relative water content, chlorophyll content, K+ content, K+/Na+ ratio, and protein and N contents were all negatively affected by 300 mM NaCl. The results obtained in the present study showed the beneficial effects of the pretreatments of two biostimulants on P. distans seedlings under non-salinity stress conditions with respect to increasing plant biomass, photosynthetic pigments, K+ content, the content of proteins, and nitrogen percentage. The results suggested that foliar spray of Bonamid® could partly diminish NaCl-caused stress on P. distans seedlings, probably due to higher accumulation of shoot biomass, photosynthetic pigments, K+/Na+ ratio, protein and N contents, phytoremediation potential, as well as upregulation of Na+/H+ antiporters located in plasma membranes and vacuoles. The highest phytoremediation potential (PP) of shoots and total biomass was detected in the plants sprayed with Bonamid® by 50.8 and 42.7% respectively, relative to that in salinity-stressed control plants. Interestingly, foliar spray with two biostimulants decreased osmoprotectants and antioxidant compounds content of shoots under salinity stress conditions. Collectively, it could be concluded that a noticeable feature of pretreatment of P. distans seedlings with Algabon® and Bonamid® is the increase in growth under NSC, whereas under SC only pretreated plants with amino acid-derived biostimulant (Bonamid®) can (partly) diminish the NaCl-induced deleterious effects in P. distans seedlings through the compartmentalization of salts in vacuoles (by upregulation of Na+/H+ antiporters).

We report for the first time that foliar spray of two commercially biostimulants (Algabon^® and Bonamid^®) could improve growth and phytoremediation potential of halophytic grass, Pucccinellia distans under the subsequent salinity stress. We also illustrated the impact of biostimulants on the mechanisms behind the improvement in tolerance of P. distans to the following salinity in regard to K⁺/Na⁺ ratio, protein and N contents, antioxidant capacity, osmoprotectant compounds, and the upregulation of Na⁺/H⁺ antiporters located in plasma membranes and vacuoles.

The Effect of Family-Centered Intervention via SMS on Life Expectancy and Self-Efficacy in Medication Regimen Compliance in Patients With Acute MI: A Randomized Clinical Trial.

BACKGROUND: Myocardial infarction (MI) is a life-threatening condition affecting an individual's physical and social circumstances. Life expectancy and self-efficacy are required to determine the risk of cardiac complications associated with this disease. This study examined the effect of family-centered intervention via short message service (SMS) on patients with acute MI's life expectancy and self-efficacy in medication regimens. METHOD: This study was a randomized, single-blind clinical trial. In 2018, 80 patients hospitalized with acute MI at educational centers affiliated with Shahrekord University were randomly assigned to the control and experimental groups. Routine intervention was performed in the control group. The experimental group was sent four educational text messages weekly for three months. Both groups' life expectancy and belief in their ability to adhere to their prescribed medication regimen were evaluated before and after the intervention. The data were analyzed using descriptive statistics, independent t, paired t, and chi-square tests via SPSS software. RESULTS: The results showed that the mean difference score of total life expectancy change was significantly different between the experimental (12.23± 10.48) and the control group (0.06±7.16) (P < 0.001). The mean difference score of self-efficacy in the experimental group (21.94±12.76) was significantly higher than that in the control group (4.66±9.49) (P<0.001). CONCLUSIONS: In patients with acute MI, using a text message intervention improved life expectancy and self-efficacy regarding medication regimens. Therefore, this intervention can be used as a low-cost and readily accessible tool to improve these patients' self-efficacy and life expectancy.

Light emitting diodes improved the metabolism of rosmarinic acid and amino acids at the transcriptional level in two genotypes of Melissa officinalis L.

In the present study, we used different LEDs to evaluate their effect on metabolic and transcriptional reprogramming of two genotypes (Ilam and Isfahan) of lemon balm grown under narrow-band LED lighting. Lemon balm plants were grown in four incubators equipped with artificial lighting and subjected to four LED lamps [White, Blue, Red, and mixed RB (Red+Blue) (70%:30%)] and in greenhouse conditions for 7weeks. The results showed significant increases in leaf number, pigment and soluble sugar contents, secondary metabolites, and calcium, magnesium, potassium and amino acid contents achieved in growth under mixed RB LEDs. As observed for the content of total phenolics, rosmarinic acid, and amino acids, the expression of genes involved in their production, including TAT , RAS , and DAHPS were also enhanced due to the mixed RB LED lighting. The best condition for both the plant growth and expression of genes was under the mixture of Red+Blue LED lamps. These observations indicate that the increase in secondary metabolites under mixed Red+Blue lights may be due to the increase in primary metabolites synthesis and the increased expression of genes that play an essential role in the production of secondary metabolites.

Improving the effects of salt stress by ß-carotene and gallic acid using increasing antioxidant activity and regulating ion uptake in Lepidium sativum L.

BACKGROUND: Plant growth and development are severely affected by soil salinity. This study was carried out to evaluate the interaction of foliar application of antioxidants (ß-carotene and gallic acid) and salt stress on Lepidium sativum seedlings. RESULTS: Our findings revealed that total dry and fresh weight were adversely affected by 25 mM NaCl salinity stress. Moreover, K+ content decreased while Na+ content increased significantly. The foliar application of ß-carotene and gallic acid significantly mitigated the effects of salt stress by regulating ion uptake, reducing H2O2 and malondialdehyde (MDA) content, as well as increasing enzymatic antioxidant activity, phenolic, glutathione, and chlorophyll content. CONCLUSIONS: ß-carotene- and gallic acid-treated plants had higher salt tolerance.

Pretreatment with LEDs regulates antioxidant capacity and polyphenolic profile in two genotypes of basil under salinity stress.

In the present study, we evaluated a pretreatment with four LED light sources (red, blue, red + blue, and white) in two genotypes (green and purple) of basil on the growth parameters, stress oxidative markers, non-enzymatic antioxidants, osmoprotectant compounds, ion content, and polyphenolic profile under both control and salinity stress conditions. The results indicated that 150 mM of NaCl decreased biomass, RWC, and K+/Na+ ratio but increased the content of proline and antioxidant capacity in the leaves of both genotypes of basil grown under GH (greenhouse) conditions. The results suggested that RB LED-exposed plants in the green genotype and R LED-exposed plants in the purple genotype improved accumulation of shoot biomass, K+/Na+ ratio, proline and soluble sugars, glutathione and ascorbate, polyphenolic profile, and thioredoxin reductase activity in the leaves of basil under both control and salinity stress conditions. NaCl stress (150 mM) increased oxidative markers, which are responsible for disturbance of routine functions of various plant cellular modules. LED light pretreatments diminished these markers under both control and salinity stress conditions. It could be concluded that intensification of non-enzymatic antioxidant systems during light-mediated priming can diminish the deleterious effects of ROS induced by NaCl stress (150 mM) through preventing the lipid peroxidation, scavenging cytotoxic H2O2, and enhancement of antioxidant potentials. Therefore, usage of LED lighting systems as a pretreatment or to supplement natural photoperiods under both control and salinity stress conditions may be advantageous for increasing biomass and phytochemical accumulation in basil.

LED light sources improved the essential oil components and antioxidant activity of two genotypes of lemon balm (Melissa officinalis L.).

BACKGROUND: Nowadays, light-emitting diodes (LEDs) as a new lighting technology, have been emerged as an alternative source of light for plants due to their wavelength specificity, the narrow width of their bands, small size, solid structure, long lifetime, and low heat generation. Here we investigated the effect of different LED light sources on the essential oil components and antioxidant activity of Melissa officinalis. Two genotypes of lemon balm (Ilam and Isfahan) were subjected to four artificial light treatments, including white, red, blue, red + blue LEDs, and greenhouse light as natural lighting. RESULTS: The LED lights significantly increased shoot fresh and dry weights and leaf number in the two genotypes as compared to greenhouse condition. The results showed that the content and composition of essential oil in the two genotypes were variable under different light treatments and the total amount of compounds in the Ilam genotype was higher than the other genotype. The results of analysis of the essential oil by GC/MS indicated that the highest amount of monoterpenes in the genotypes was related to citronellal under red + blue LED lamps (15.3 and 17.2% in Ilam and Isfahan genotypes, respectively) but blue, white, and greenhouse condition had the most effect on sesquiterpenes content in both genotypes. The results showed that the observed variation between the two genotypes in the essentials oil composition was related to the relative percentage of the constituents and not to the appearance or lack of a specific component. Red + blue lighting also provided the highest radical scavenging activity in both genotypes (80.77 and 82.09% for Ilam and Isfahan genotypes, respectively). Based on principal component analyses (PCA), three main groups were identified regarding genotypes and all light treatments. CONCLUSIONS: Overall, results indicated that the essentials oil composition of two genotypes of lemon balm was affected both qualitatively and quantitatively by different LED light sources; hence, LED lights might be used to improve monoterpenes, sesquiterpenes, and antioxidant activity in the selected genotypes.

Comparative physiological and proteomic analysis indicates lower shock response to drought stress conditions in a self-pollinating perennial ryegrass.

We investigated the physiological and proteomic changes in the leaves of three Lolium perenne genotypes, one Iranian putative self-pollinating genotype named S10 and two commercial genotypes of Vigor and Speedy, subjected to drought stress conditions. The results of this study indeed showed higher RWC (relative water content), SDW (shoot dry weight), proline, ABA (abscisic acid), nitrogen and amino acid contents, and antioxidant enzymes activities of S10 under drought stress in comparison with the two other genotypes. A total of 915 proteins were identified using liquid chromatography-mass spectrometry (LC/MS) analysis, and the number of differentially abundant proteins between normal and stress conditions was 467, 456, and 99 in Vigor, Speedy, and S10, respectively. Proteins involved in carbon and energy metabolism, photosynthesis, TCA cycle, redox, and transport categories were up-regulated in the two commercial genotypes. We also found that some protein inductions, including those involved in amino acid and ABA metabolisms, aquaporin, HSPs, photorespiration, and increases in the abundance of antioxidant enzymes, are essential responses of the two commercial genotypes to drought stress. In contrast, we observed only slight changes in the protein profile of the S10 genotype under drought stress. Higher homozygosity due to self-pollination in the genetic background of the S10 genotype may have led to a lower variation in response to drought stress conditions.

LED lights increase an antioxidant capacity of Arabidopsis thaliana under wound-induced stresses.

A comparison among four light emitting diode (LED) lights including red LED (R), blue LED (B), red (70%) + blue (30%) LED (RB) and white LED (W) as well as fluorescent (F) light was made on antioxidative capacity of Arabidopsis thaliana (L.) Heynh. in response to wounding. Under wound-stress condition, LED-exposed plants, especially RB-irradiated plants, maintained significantly higher shoot dry weight and antioxidant enzymes activities compared with those irradiated with fluorescent lights. The highest amounts of both chlorophyll a and b were observed in the leaves treated with B light. Also, the concentration of H2O2 was higher under the condition of RB and B lights compared with the other light environments. The highest amount of malondialdehyde was measured in plants exposed to F and B lights. Similarly, wounded leaves under F and B light conditions showed the maximum lipoxygenase activity, whereas R-exposed leaves had the lowest lipoxygenase activity. In contrast, the highest level of phenolic compounds was found in R and RB exposed leaves in response to wounding. Among the five light treatments, RB and B lights were more effective in stimulating anthocyanin synthesis; however, RB-exposed plants were more efficient in the late-induction of the PAL gene (phenylalanine ammonia lyase catalyses the first step of the general phenylpropanoid pathway). Collectively, we reasoned that RB light condition gives a superior capacity to Arabidopsis thaliana to tolerate wound-stress. Also, we propose the probable signalling role of ROS in light-stimulated wound responses in Arabidopsis.

LED light mediates phenolic accumulation and enhances antioxidant activity in Melissa officinalis L. under drought stress condition.

The popularity of lemon balm in conventional medicine is suggested by the existence of two groups of compounds, namely essential oil and phenylpropanoids pathway derivatives. One of the promising approaches to improve tolerance to drought stress induced oxidative damage in seedlings grown in greenhouses and plant growth chambers is replacing the traditional and high-cost light technologies by recently developed light emitting diodes (LED). In this experiment, we analyzed the role of various LED lights including red (R), blue (B), red (70%) + blue (30%) (RB), and white (W) as well as normal greenhouse light (as control) to stimulate defense mechanisms against drought stress in two genotypes of Melissa officinalis L. The present study demonstrates that pre-treatment with LEDs with high-intensity output for 4 weeks alleviated harmful effects of drought stress in the two genotypes. Under drought stress, RB LED pre-treated plantlets of the two genotypes exhibited the highest relative growth index of shoot and root and total phenolic and anthocyanin content compared to those irradiated with other LEDs and greenhouse lights. The highest amount of malondialdehyde level was detected in R LED exposed plants. In response to drought, LED-exposed plants especially RB light-irradiated plants of the two genotypes maintained significantly higher antioxidant and phenylalanine ammonia-lyase (PAL) enzyme activities and higher expression level of the PAL1 and 4CL-1 genes compared to those irradiated with greenhouse light. We concluded that RB LED light provides a better growth condition and resistance to drought stress for the two genotypes of lemon balm by the highest antioxidant activity and the least amount of damage to the cell membranes. Our data suggest that LED light pre-treatments as moderate stress activate antioxidant systems, enhance the scavenging of ROS and induce drought stress tolerance in the two genotypes of lemon balm plants.

Chitosan enhances rosmarinic acid production in shoot cultures of Melissa officinalis L. through the induction of methyl jasmonate.

BACKGROUND: Chitosan is a polycationic polysaccharide derived from chitin that has been recognized as an effective elicitor in the production of secondary metabolites of many medicinal plants. In this study, the effect of abiotic elicitor (chitosan) at various concentrations on rosmarinic acid (RA) and total phenolic accumulation in shoot cultures of lemon balm was investigated. RESULTS: Treatment of shoots by chitosan led to a noticeable induction of phenylalanine ammonia-lyase (PAL), catalase (CAT), guaiacol peroxidase (GPX) and lipoxygenase (LOX) activities. Besides, the expression of PAL1, TAT and RAS genes and accumulation of RA and phenolic compound increased in chitosan-treated lemon balm shoots. Chitosan treatment also increased H2O2 accumulation and the expression of RBOH, an essential gene implicated in ROS production. Also, the up-regulation of the OPR gene by exogenous chitosan was associated with the induction of endogenous JA determined by GC-MASS. CONCLUSION: The present study showed that the induced production of rosmarinic acid by chitosan involves the trigger of defense-related enzymes, up-regulated expression of TAT and RAS genes, and stimulation of JA biosynthesis.

Improvement in drought tolerance of lemon balm, Melissa officinalis L. under the pre-treatment of LED lighting.

Stress priming (pre-exposure of plants to various types of moderate stresses) could affect plant responses to subsequent severe stresses. Drought stress is one of the major threats to plants which reduces the global agricultural productions. Here we demonstrated that light emitting diodes (LEDs)-driven tolerant to drought stress in lemon balm plantlets was highly correlated with priming with these lighting sources. Plantlets of the two genotypes of M. officinalis L. were first grown in 4 incubators with different LED lamps, including white LEDs (380-760 nm), blue LEDs (460 nm), red LEDs (650 nm) and red + blue LEDs (70%:30%), in a greenhouse for 4 weeks. The potted plants were then subjected to drought stress. Under drought stress, LED-primed plants maintained significantly higher fresh and dry weight, relative water content (RWC), concentration of soluble sugars, antioxidant activity and higher content of proline, H2O2, abscisic acid (ABA) and rosmarinic acid than non-primed plants. The results of Real-Time RT-PCR confirmed that LED pretreatment up-regulated the expression levels of respiratory burst oxidase homologues (RBOHs) or NADPH oxidase, 9-cis epoxy carotenoid dioxygenase (NCED), and rosmarinic acid synthase (RAS), while down-regulated that of ABA 8'-hydroxylase (ABA8Ox). These findings suggest, for the first time, that pre-treatment of plants with red + blue LEDs could improve their growth and quality under drought stress.

The combined effects of three-dimensional cell culture and natural tissue extract on neural differentiation of P19 embryonal carcinoma stem cells.

Tissue engineering, as a novel transplantation therapy, aims to create biomaterial scaffolds resembling the extracellular matrix in order to regenerate the damaged tissues. Adding bioactive factors to the scaffold would improve cell-tissue interactions. In this study, the effect of chitosan polyvinyl alcohol nanofibres containing carbon nanotube scaffold with or without active bioglass (BG+ /BG- ), in combination with neonatal rat brain extract on cell viability, proliferation, and neural differentiation of P19 embryonic carcinoma stem cells was investigated. To induce differentiation, the cells were cultured in α-MEM supplemented with neonatal rat brain extract on the scaffolds. The expression of undifferentiated stem cell markers as well as neuroepithelial and neural-specific markers was evaluated and confirmed by real-time Reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence procedures. Finally, the three-dimensional (3D) cultured cells were implanted into the damaged neural tubes of chick embryos, and their fates were followed in ovo. Based on the histological and immunofluorescence observations, the transplanted cells were able to survive, migrate, and penetrate into the host embryonic tissues. Gene network analysis suggested the possible involvement of neurotransmitters as a downstream target of synaptophysin and tyrosine hydroxylase. Overall, the results of this study indicated that combining the effects of 3D cell culture and natural brain tissue extract can accelerate the differentiation of P19 embryonic carcinoma cells into neuronal phenotype cells.

Cytotoxic, antioxidant and phytochemical analysis of Gracilaria species from Persian Gulf.

BACKGROUND: Marine algae, also called seaweeds, are abundantly present in the coastal area of Iran, especially in Persian Gulf. These plants contain important phytochemical constituents and have potential biological activities. The present study investigated the presence of phytochemical constituents and total phenolic quantification of the seaweeds Gracilaria salicornia and Gracilaria corticata. Cytotoxicity of seaweeds was tested against HT-29, HeLa, and MCF-7 cell lines. Antioxidant potential of these two Gracilaria species was also analyzed. MATERIALS AND METHODS: Extracts of G. salicornia and G. corticata were subjected to phytochemical and cytotoxicity tests. Phytochemical screenings were employed to identify the chemical constituents and total phenolic content. Cytotoxicity was characterized by IC50 of human cancer cell lines (MCF-7, HeLa, and HT-29) using sulforhodamine assay. Antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl. RESULTS: The analysis revealed that tannins were the most abundant compounds in G. corticata while sterols and triterpenes were the most abundant ones in G. salicornia, but the total phenolic content of the two seaweeds was similar. Cytotoxic results showed that both species could inhibit cell growth effectively, especially against HT-29 cell line. CONCLUSION: Considerable phytochemicals, high antioxidant potential, and moderate cytotoxic activity of G. salicornia and G. corticata make them appropriate candidates for further studies and identification of their bioactive principles.

Induction of pancreatic ß cell gene expression in mesenchymal stem cells.

Transdifferentiattion potential of mesenchymal stem cells (MSCs) into insulin-producing cells (IPCs) has been suggested recently. In our recent works, we demonstrated the high performance of mouse neonate pancreas extract (MPE) in the production of functional IPCs from carcinoma stem cells. In this study, MPE was used to generate IPCs from MSCs without any genetic manipulation. To this end, bone marrow MSCs were isolated and characterized. In order to differentiate, MSCs were induced by selection of nestin-expressing cells and treatment with 100 µg/mL MPE. Morphological features of the differenti-ated cells were confirmed by dithizone staining. Immunoreactivity to insulin receptor beta, proinsulin, insulin, and C-peptide was observed by immunoflourescence. We also quantified glucose-dependent insulin production and secretion by ELISA. Real-time PCR indicated the expressions of ß cell-related genes, PDX-1, INS1, INS2, EP300, and CREB1, in IPC cells. Possible pathways governed by CREB1, EP300, and PDX-1 transcription factors in differentiation of MSCs to IPCs were determined based on Gene Set Enrichment (GSE) approach at P = 0.05. Pathway discovery highlighted the negative regulatory effects of MIR124-2, HDAC5 protein, REST, and NR0B2 transcription factors on expression of CREB1, EP300, and PDX-1 and inhabitation of IPC differentiations. In contrast, a crosstalk between FOXA2 and TCF7L2 transcription factors, DNA-PK complex, KAT2B protein positively interacting with PDX-1, CREB1, EP300 resulted in the induction of IPC and following insulin production. In conclusion, we report an efficient, simple, and easy method for production of functional IPCs from MSCs by MPE treatment.

Differentiation of P19 embryonal carcinoma stem cells into insulin-producing cells promoted by pancreas-conditioned medium.

The ability of embryonal carcinoma )EC (stem cells to generate insulin-producing cells (IPCs) is still unknown. We examined the trophic effects of pancreas-conditioned medium (PCM) on in vitro production of IPCs. Initially, P19 EC cells were characterized by the expression of stem cell markers, Oct3/4, Sox-2 and Nanog. To direct differentiation, P19-derived embryoid bodies (EBs) were induced by selection of nestin-positive cells and treatment with different concentrations of PCM. Morphological studies documented the presence of islet-like cell IPCs clusters. The differentiated cells were immunoreactive for ß cell-specific proteins, including insulin, proinsulin, C-peptide and insulin receptor-ß. The expression of genes related to pancreatic ß cell development and function (PDX-1, INS1, INS2, EP300 and CREB1) was confirmed by qPCR. During differentiation, the expression of EP300 and CREB1 increased by 2.5 and 3.1 times, respectively. In contrast, a sharp decrease in the expression of Oct3/4, Sox-2 and Nanog by 4, 1.5 and 1.5 times, respectively, was observed. The differentiated cells were functionally active, synthesizing and secreting insulin in a glucose-regulated manner. Network prediction highlighted crosstalk between PDX-1 transcription factor and INS2 ligand in IPC generation and revealed positive regulatory effects of EP300, CREB1, PPARA, EGR, KIT, GLP1R, and PKT2 on activation of PDX-1 and INS2. This is the first report of the induction of IPC differentiation from EC cells by using neonate mouse PCM. Since P19 EC cells are widely available, easily cultured without feeders and do not require special growth conditions, they would provide a valuable tool for studying pancreatic ß cell differentiation and development. Copyright © 2016 John Wiley & Sons, Ltd.

Arbuscular mycorrhiza affects nickel translocation and expression of ABC transporter and metallothionein genes in Festuca arundinacea.

Mycorrhizal fungi are key microorganisms for enhancing phytoremediation of soils contaminated with heavy metals. In this study, the effects of the arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae (=Glomus mosseae) on physiological and molecular mechanisms involved in the nickel (Ni) tolerance of tall fescue (Festuca arundinacea = Schedonorus arundinaceus) were investigated. Nickel addition had a pronounced negative effect on tall fescue growth and photosynthetic pigment contents, as well as on AMF colonization. Phosphorus content increased markedly in mycorrhizal plants (M) compared to non-inoculated (NM) ones. However, no significant difference was observed in root carbohydrate content between AMF-inoculated and non-inoculated plants. For both M and NM plants, Ni concentrations in shoots and roots increased according to the addition of the metal into soil, but inoculation with F. mosseae led to significantly lower Ni translocation from roots to the aboveground parts compared to non-inoculated plants. ABC transporter and metallothionein transcripts accumulated to considerably higher levels in tall fescue plants colonized by F. mosseae than in the corresponding non-mycorrhizal plants. These results highlight the importance of mycorrhizal colonization in alleviating Ni-induced stress by reducing Ni transport from roots to shoots of tall fescue plants.

ABC transporter and metallothionein expression affected by NI and Epichloe endophyte infection in tall fescue.

Epichloe endophytes are symbiotic fungi which unlike mycorrhiza grow within aerial parts of host plants. The fungi may increase host tolerance to both biotic and abiotic stresses. In this study, the effect of endophyte infection on growth and tolerance, carbohydrate contents and ABC (ABC transporter) and MET (metallothionein) expression in the leaves of tall fescue (Festuca arundinacea) plants cultivated in Ni polluted soil were evaluated. The endophyte infected (E+) and non-infected (E-) fescue plants were cultivated in soil under different Ni concentrations (30, 90 and 180mgkg(-1)). Growth parameters including root, shoot, total biomass, tiller number and total chlorophyll content of plants and H2O2 content of shoots were measured at the end of experiment. Ni translocation to the shoots, carbohydrate contents in roots and expression of ABC and MET of the leaves were also measured after 10 weeks of growth. Results demonstrated the beneficial effect of endophyte association on growth and Ni tolerance of tall fescue under Ni stress through an avoidance mechanism (reduction of Ni accumulation and translocation to the shoots). Endophyte infected plants showed less ABC and MET expression compared to the endophyte free plants. In endophyte free plants, H2O2 production had a significant positive correlation with genes expression, indicating that an increase in H2O2 might be involved in the up-regulation of ABC and MET under Ni stress.

Efficient and simple production of insulin-producing cells from embryonal carcinoma stem cells using mouse neonate pancreas extract, as a natural inducer.

An attractive approach to replace the destroyed insulin-producing cells (IPCs) is the generation of functional ß cells from stem cells. Embryonal carcinoma (EC) stem cells are pluripotent cells which can differentiate into all cell types. The present study was carried out to establish a simple nonselective inductive culture system for generation of IPCs from P19 EC cells by 1-2 weeks old mouse pancreas extract (MPE). Since, mouse pancreatic islets undergo further remodeling and maturation for 2-3 weeks after birth, we hypothesized that the mouse neonatal MPE contains essential factors to induce in vitro differentiation of pancreatic lineages. Pluripotency of P19 cells were first confirmed by expression analysis of stem cell markers, Oct3/4, Sox-2 and Nanog. In order to induce differentiation, the cells were cultured in a medium supplemented by different concentrations of MPE (50, 100, 200 and 300 µg/ml). The results showed that P19 cells could differentiate into IPCs and form dithizone-positive cell clusters. The generated P19-derived IPCs were immunoreactive to proinsulin, insulin and insulin receptor beta. The expression of pancreatic ß cell genes including, PDX-1, INS1 and INS2 were also confirmed. The peak response at the 100 µg/ml MPE used for investigation of EP300 and CREB1 gene expression. When stimulated with glucose, these cells synthesized and secreted insulin. Network analysis of the key transcription factors (PDX-1, EP300, CREB1) during the generation of IPCs resulted in introduction of novel regulatory candidates such as MIR17, and VEZF1 transcription factors, as well as MORN1, DKFZp761P0212, and WAC proteins. Altogether, we demonstrated the possibility of generating IPCs from undifferentiated EC cells, with the characteristics of pancreatic ß cells. The derivation of pancreatic cells from EC cells which are ES cell siblings would provide a valuable experimental tool in study of pancreatic development and function as well as rapid production of IPCs for transplantation.