Involvement of polyamine metabolism in the response of Medicago truncatula genotypes to salt stress

Salinity constitutes one of the most important causes leading to severe reduction in plant yield. Several reports correlate the accumulation of polyamines in plants with tolerance to abiotic stress cues. The present study examined three Medicago truncatula genotypes with differing sensitivities to salinity (TN1.11, tolerant; Jemalong A17, moderately sensitive; TN6.18, sensitive), with the aim of examining the genotype-specific involvement of the polyamine metabolic pathway in plant response to salinity. The study was carried out with leaves harvested 48 h after watering plants with 200 mM NaCl. A comprehensive profile of free polyamines was determined using high performance liquid chromatography. All genotypes showed spermidine and spermine as the most abundant polyamines under control conditions. In salinity conditions, spermine levels increased at the expense of putrescine and spermidine, indicating a drift of polyamine metabolism towards the synthesis of increasing polycationic forms as a stress response. The increasing balance between high and low polycationic forms was clearly diminished in the salt-sensitive genotype TN6.18, showing a clear correlation with its sensitive phenotype. The polyamine metabolic profile was then supported by molecular evidence through the examination of polyamine metabolism transcript levels by RT-qPCR. General suppression of genes that are involved upstream in the PA biosynthetic pathway was determined. Contrarily, an induction in the expression of genes involved in the biosynthesis of spermine and spermidine was observed, in agreement with the metabolic analysis. A significant induction in diamino oxidase expression, involved in the catabolism of putrescine, was specifically found in the sensitive genotype ΤΝ6.18, indicating a distinct metabolic response to stress. Present findings highlight the involvement of polyamines in the defense response of Medicago genotypes showing sensitivity to salt stress

Operation Ajax : Studie om USA:s och Storbritanniens involvering i statskuppen, Iran 1953

University of Växjö, School of Social Sciences Course: PO 5363, Political Science, G3 Title: the Role of the USA’s and Great Britain in the Coup d'Etat, Iran 1953 Author: Ashkan Panahirad Supervisor: Lennart Bergfeldt The purpose of this study is to examine Great Britain’s and US’ motives and action alternatives in regards to the Coup d'état against the iranian regime under Mossadegh in 1953. The method used is motive analysis (investigates the actors motives). The theories used are Rational actors model and Governmental politics. Rational actor model allows states to choose among a set of alternatives displayed in a particular situation in order to achieve their goals. Governmental politics explains what happens in states as a result of bargaining games between important actors in the government. Analysis from the rational actor model shows that the motives behind the Coup d'état were oil, economical reasons, Iran and communism. Coup d'état was the most rational action for them to achieve their goals. Governmental politics reveal the shifting of policies from one administration to another. While Clement Attlee’s government and Harry Truman’s administration where more moderate, Winston Churchill’s and Eisenhower’s where more eager to replace Mossadegh, which finally lead to a Coup d'éta

Agenda Setting in the OECD - NGOs influence on OECD's Development Agenda

The proliferation of NGOs with an international agenda has been one of the most profound trends in international relations during the past years. Their role in the outcome of international politics has however been insufficiently theorized. The aim of this research was to fill this gap by explain how and under what conditions NGOs were able to influence the agenda of OECD in development policies. The empirical focus of this study is on the two international meeting that were held in 2005 and 2008, organized by OECD development committee, DAC. The method used in this study is process tracing (studying causes that led to an outcome). The employment of the method evidently generates an analytical framework constituted of framing processes and political opportunity theory. It was concluded that NGOs by arranging several meetings were able produce joint action frames, hence creating a broader alignment for their claims. The notion of “democratic ownership” was developed to a master frame, generating a consensus among NGOs and increasing their credibility among the members of DAC. Their frames would however not been legitimized if the sufficient political opportunities were not created. The analysis of political opportunity concluded that NGOs were able to legitimize their frames by gaining access to the OECD, through the creation of DAC’s Advisory Group. The increased access was the result of the internal restructuring of the OECD which generated a more inclusive partnership towards non-members. The political alignment with some of DAC’s member-states further enhanced NGOs credibility in order to legitimize their frames in the agenda of DAC

Effect of salicylic acid foliar application on Vitis vinifera L. cv. 'Sultana’ under salinity stress

The current survey aimed to study the effect of exogenous salicylic acid (SA) application on salinity stress of grapevine cv. ’Sultana’. The leaves of hydroponically cultivated grapes that were under 0, 75 and 150 mM salinity conditions treated with 0, 0.5, 1 and 1.5 mM SA and after two weeks, the factors such as Na+, K+, proline and MDA contents, leaf electrolyte leakage and enzymatic activities were measured. The results showed that all SA treatments were significantly effective at tolerance enhancement by reduction in Na+/K+ ratio, leaf electrolyte leakage, MDA and H2O2 values and promotion in proline content and the enzymatic activities (POD, APX, CAT and SOD) of grapes. These results indicated that SA application at salinity condition could be applied as a promising method for increasing the salinity tolerance of ‘Sultana’ grapes

Improvement of Postharvest Quality of Plum (Prunus domestica L.) Using Polysaccharide-Based Edible Coatings

Polysaccharide-based edible coatings are served as an attractive preservation method for postharvest maintenance of most fruits. The current study examined the effect of carboxymethylcellulose (CMC)- and pectin (Pec)-based edible coatings on titratable acidity (TA), firmness; vitamin C (vit C); total soluble solids (TSS); pH; total phenolics; anthocyanin and flavonoid contents; total antioxidant capacity (based on 1,1-Diphenyl-2-picryl-hydrazyl hydrate (DPPH)); the activities of peroxidase (POD), polyphenol oxidase (PPO) and polygalacturonase (PG) enzymes; and weight loss during cold storage. The results showed that each coating and their combinations caused positive effects in all measured parameters except weight loss. The applied coatings preserved firmness and improved total phenols, anthocyanin and flavonoid contents, antioxidant capacity and POD activity. In addition, TSS decreased and pH values remained more or less stable with the coating application. The coatings delayed TA and vitamin C loss, and decreased enzymatic activities such as PPO and PG. It could be stated that CMC at 1% and Pec at 1.5% separately demonstrated the best results for most of the measured parameters; and 0.5% Pec + 1.5% CMC could be considered as the best combination. In conclusion, application of CMC, Pec, or their combinations would be considered as an interesting approach to improve postharvest quality characteristics of plum fruit

Fish Waste—A Novel Bio-Fertilizer for Stevia (<i>Stevia rebaudiana</i> Bertoni) under Salinity-Induced Stress

Currently, different strategies, including the application of bio-fertilizers, are used to ameliorate the adverse effects posed by salinity stress as the major global problem in plants. Fish waste is suggested as a novel bio-fertilizer to mitigate the effects of biotic and abiotic stresses. In this investigation, an experiment was conducted to investigate the effects by applying different concentrations (0, 5, 10, and 15% (v/v)) of fish waste bio-fertilizer on stevia plants grown under salt stress conditions (0, 20, 40, and 60 mM of NaCl). Results showed that salinity negatively affected growth parameters, the photosynthetic pigments, the relative water content, and the chlorophyll fluorescence parameters while increased the activity of antioxidant enzymes, total phenol, hydrogen peroxide (H2O2), malondialdehyde (MDA), proline, and total carbohydrates compared with control samples. On the other hand, the application of fish waste bio-fertilizer mitigated the effects of salinity stress by enhancing growth and mitigating stress-relative markers, especially at the highest salinity level (60 mM). Overall, fish waste bio-fertilizer could be considered a sustainable, innovative approach for the alleviation of salinity stress effects in plants and, in addition, fish waste bio-fertilizer did not cause more salinity issues, at least with the applied doses and experiment time, which is an imperative aspect

Modified multiwall carbon nanotubes display either phytotoxic or growth promoting and stress protecting activity in Ocimum basilicum L. in a concentration-dependent manner

Carbon-based materials including multiwall carbon nanotubes (MWCNTs) have been recently implicated in a number of reports dealing with their potential use in agriculture, leading to contradictory findings. In this study, MWCNTs were successfully functionalized with carboxylic acid groups (MWCNTs-COOH) in order to increase water dispersion. Hydroponically cultured sweet basil (Ocimum basilicum L.) seedlings were subjected to four concentrations (0, 25, 50 and 100 mg L-1) of MWCNTs-COOH under three salt stress levels (0, 50 and 100 mM NaCl). An array of agronomic, physiological, analytical and biochemical parameters were evaluated in an attempt to examine the potential use of MWCNTs in plants under optimal and abiotic stress conditions. Application of MWCNTs-COOH at optimum concentration (50 mg L-1) could ameliorate the negative effects of salinity stress by increasing chlorophyll and carotenoids content and inducing non-enzymatic (i.e. phenolic content) and enzymatic antioxidant components (i.e. ascorbate peroxidase (APX), catalase (CAT) and guaiacol peroxidase (GP) activity). Furthermore, MWCNTs-COOH treatments under optimal conditions induced plant growth, while a significant increase (P ≤ 0.01) was recorded in essential oil content and compound profile. On the other hand, biochemical and epifluorescence microscopy evidence suggested that high dosage (100 mg L-1) of MWCNTs-COOH leads to toxicity effects in plant tissue. Overall, the positive response of plants to low concentrations of MWCNTs-COOH under control and abiotic stress conditions renders them as potential novel plant growth promoting and stress protecting agents, opening up new perspectives for their use in agriculture

Foliar application of chitosan-putrescine nanoparticles (CTS-Put NPs) alleviates cadmium toxicity in grapevine (Vitis vinifera L.) cv. Sultana: modulation of antioxidant and photosynthetic status

Abstract Background Cadmium (Cd) stress displays critical damage to the plant growth and health. Uptake and accumulation of Cd in plant tissues cause detrimental effects on crop productivity and ultimately impose threats to human beings. For this reason, a quite number of attempts have been made to buffer the adverse effects or to reduce the uptake of Cd. Of those strategies, the application of functionalized nanoparticles has lately attracted increasing attention. Former reports clearly noted that putrescine (Put) displayed promising effects on alleviating different stress conditions like Cd and similarly chitosan (CTS), as well as its nano form, demonstrated parallel properties in this regard besides acting as a carrier for many loads with different applications in the agriculture industry. Herein, we, for the first time, assayed the potential effects of nano-conjugate form of Put and CTS (CTS-Put NP) on grapevine (Vitis vinifera L.) cv. Sultana suffering from Cd stress. We hypothesized that their nano conjugate combination (CTS-Put NPs) could potentially enhance Put proficiency, above all at lower doses under stress conditions via CTS as a carrier for Put. In this regard, Put (50 mg L− 1), CTS (0.5%), Put 50 mg L− 1 + CTS 0.5%” and CTS-Put NPs (0.1 and 0.5%) were applied on grapevines under Cd-stress conditions (0 and 10 mg kg− 1). The interactive effects of CTS-Put NP were investigated through a series of physiological and biochemical assays. Results The findings of present study clearly revealed that CTS-Put NPs as optimal treatments alleviated adverse effects of Cd-stress condition by enhancing chlorophyll (chl) a, b, carotenoids, Fv / Fm , Y(II), proline, total phenolic compounds, anthocyanins, antioxidant enzymatic activities and decreasing Y (NO), leaf and root Cd content, EL, MDA and H2O2. Conclusions In conclusion, CTS-Put NPs could be applied as a stress protection treatment on plants under diverse heavy metal toxicity conditions to promote plant health, potentially highlighting new avenues for sustainable crop production in the agricultural sector under the threat of climate change