56 research outputs found

    Molecular Dissection of Maize-Sporisorium reilianum Interactions: Host Developmental Changes and Pathogen Effectors

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    Sporisorium reilianum causes head smut disease on maize. Symptoms of S. reilianum become obvious when the fungus forms spores and induces phyllody in the inflorescences. This study aimed to provide an understanding of how S. reilianum changes the developmental program of maize, and to identify and characterize symptom and virulence determinants of the pathogen. The maize-S. reilianum interaction was approached from both sides. From the side of maize, the induced alterations on morphology, transcription, hormone level and concentration of reactive oxygen species (ROS) were investigated. Morphological analysis showed that S. reilianum infection promoted outgrowth of subapical ears suggesting that fungal presence suppressed apical dominance. S. reilianum colonization also led to an increase in the total cytokinin and auxin content of the inflorescence and an accumulation of ROS that could explain suppression of apical dominance. Furthermore, S. reilianum infection triggered loss of floral organ and meristem identities, and loss of meristem determinacy. Microarray analysis showed that these developmental changes were accompanied with transcriptional regulation of genes known or proposed to regulate floral organ and meristem identities, and meristem determinacy in maize. From the side of S. reilianum, genome comparison with the closely related smuts Ustilago maydis and Ustilago hordei was performed to predict potential candidate genes with function in symptom formation or virulence on maize. Functional characterization of the candidates showed that deletion of dicer did not lead to changes in virulence or in the mutant behavior in response to different stresses. In addition, genes with avirulence functions (sr10057, sr10060, sruni1 and sruni2) and those with virulence functions (clusters 19A, cluster 5-1uni and sruni5) were identified. Cluster 19A3 was suggested to encode leaf senescence inhibitors, since its deletion triggered leaf tip death. Additionally, vag1 fulfilled avirulence and virulence functions in leaves and nodes, respectively. Two genes, sad1 and sad2 showed involvement in suppression of apical dominance. SAD1 and VAG1 were degraded in a leaf-specific manner. SAD1 localized to the nucleus and the cytoplasm when expressed in plant cells and, interacted with the effector MIG1 and plant proteins involved in ubiquitination, nuclear functions and signaling. These interaction partners could shape the mechanism of tissue-specific degradation of SAD1 and the role of SAD1 in suppression of apical dominance. Hence, a molecular link could be established between specific effectors of S. reilianum and induced developmental changes in the host

    Screening of secreted proteins of Sporisorium reilianum f. sp. zeae for cell death suppression in Nicotiana benthamiana

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    Sporisorium reilianum f. sp. zeae (SRZ) is a biotrophic fungus causing head smut in maize. Maize infection with SRZ leads to very little cell death suggesting the presence of cell-death suppressinpg effectors. Several hundred effector proteins have been predicted based on genome annotation, genome comparison, and bioinformatic analysis. For only very few of these effectors, an involvement in virulence has been shown. In this work, we started to test a considerable subset of these predicted effector proteins for a possible function in suppressing cell death. We generated an expression library of 62 proteins of SRZ under the control of a strong constitutive plant promoter for delivery into plant cells via Agrobacterium tumefaciens -mediated transient transformation. Potential apoplastic effectors with high cysteine content were cloned with signal peptide while potential intracellular effectors were also cloned without signal peptide to ensure proper localization after expression in plant cells. After infiltration of Nicotiana benthamiana leaves, infiltration sites were evaluated for apparent signs of hypersensitive cell death in absence or presence of the elicitin INF1 of Phytophthora infestans . None of the tested candidates was able to induce cell death, and most were unable to suppress INF1-induced cell death. However, the screen revealed one predicted cytoplasmic effector (sr16441) of SRZ that was able to reliably suppress INF1-induced cell death when transiently expressed in N. benthamiana lacking its predicted secretion signal peptide. This way, we discovered a putative function for one new effector of SRZ

    EXTRACTION, ISOLATION, AND CHARACTERIZATION OF BIOACTIVE COMPOUNDS AND ESSENTIAL OIL FROM SYZYGIUM JAMBOS

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    Objectives: Over the past few decades, phenolic compounds become important due to it has been associated with protection against different diseasesand sensory point of vision. Hence, at the present study, there has been a growing interest to carry out structural elucidation and characterization ofthe pure isolates from Syzygium jambos.Methods: S. jambos dried powder leaves were extracted by soaking in 85% methanol solvent at room temperature 25±2°C. The antioxidative activityof the isolates was assessed according to 2,2'-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and phosphomolybdenum assays.Results: A total of 8 compounds were isolated from the n-butanol extract of S. jambos (Family Myrtaceae) plant, they were identified as quercetin-3-O-rutinoside (1), prenylbenzoic acid 4-β-D-glucoside (2), morolic acid 3-O-caffeate (3), 5,4'-dihydroxy, 7-methoxy, 6-methyl-flavone (4),3,4,5-trihydroxybenzoic acid (5), quercetin (6), isoetin-7-O-β-D-glucopyranoside (7), and (4'-hydroxy-3'-methoxyphenol-β-D-[6-O-(4â€-hydroxy-3â€,5â€-dimethoxylbenzoate)] glucopyranoside) (8). Compounds 5 and 6 showed the most radical scavengers among the tested compounds with SC50 values of5.50 and 4.30 μg/ml, respectively, compared to ascorbic acid as standard and the total antioxidant capacity (TAC) values of 605.0 and 680.59 mg ascorbicacid equivalent/g compound, respectively. In vitro antimicrobial activities of the isolated compounds were tested using disc agar plate method againstfour pathogenic microbial strains including Gram-positive, Gram-negative bacteria and yeast with inhibition zones from 9 to 19 mm. Gas chromatographymassspectrometry analysis for the essential oil provides twenty four identified components representing 92% of its total oil composition.Conclusion: The results supported that S. jambos could be attributed to sources of natural antioxidant and antimicrobial applications

    Mulberry based zinc nano-particles mitigate salinity induced toxic effects and improve the grain yield and zinc bio-fortification of wheat by improving antioxidant activities, photosynthetic performance, and accumulation of osmolytes and hormones

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    Salinity stress (SS) is a challenging abiotic stress that limits crop growth and productivity. Sustainable and cost effective methods are needed to improve crop production and decrease the deleterious impacts of SS. Zinc (Zn) nanoparticles (NPs) have emerged as an important approach to regulating plant tolerance against SS. However, the mechanisms of SS tolerance mediated by Zn-NPs are not fully explained. Thus, this study was performed to explore the role of Zn-NPs (seed priming and foliar spray) in reducing the deleterious impacts of SS on wheat plants. The study comprised different SS levels: control, 6 and 12 dS m−1, and different Zn-NPs treatments: control, seed priming (40 ppm), foliar spray (20 ppm), and their combination. Salinity stress markedly reduced plant growth, biomass, and grain yield. This was associated with enhanced electrolyte leakage (EL), malondialdehyde (MDA), hydrogen peroxide (H2O2), sodium (Na), chloride (Cl) accumulation, reduced photosynthetic pigments, relative water contents (RWC), photosyntetic rate (Pn), transpiration rate (Tr), stomata conductance (Gs), water use efficiency (WUE), free amino acids (FAA), total soluble protein (TSP), indole acetic acid (IAA), gibberellic acid (GA), and nutrients (Ca, Mg, K, N, and P). However, the application of Zn-NPs significantly improved the yield of the wheat crop, which was associated with reduced abscisic acid (ABA), MDA, H2O2 concentration, and EL, owing to improved antioxidant activities, and an increase in RWC, Pn, Tr, WUE, and the accumulation of osmoregulating compounds (proline, soluble sugars, TSP, and FAA) and hormones (GA and IAA). Furthermore, Zn-NPs contrasted the salinity-induced uptake of toxic ions (Na and Cl) and increased the uptake of Ca, K, Mg, N, and P. Additionally, Zn-NPs application substantially increased the wheat grain Zn bio-fortification. Our results support previous findings on the role of Zn-NPs in wheat growth, yield, and grain Zn bio-fortification, demonstrating that beneficial effects are obtained under normal as well as adverse conditions, thanks to improved physiological activity and the accumulation of useful compounds. This sets the premise for general use of Zn-NPs in wheat, to which aim more experimental evidence is intensively being sought. Further studies are needed at the genomic, transcriptomic, proteomic, and metabolomic level to better acknowledge the mechanisms of general physiological enhancement observed with Zn-NPs application

    Dissolution Enhancement and Formulation of Rapid-Release Lornoxicam Mini-Tablets

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    The aim was to enhance the dissolution of lornoxicam (LOR) and to produce mini-tablets with an optimised system to provide a rapid-release multi-particulate formulation. LOR systems were prepared through co-evaporation with either polyethylene glycol 6000 or Pluronic® F-68 (PLU) and adsorption onto Neusilin® US2 alone or co-adsorption in the presence of different amounts of polysorbate 80. All systems were characterised by FT-IR, differential scanning calorimetry, X-ray diffraction, flowability and dissolution techniques. Mini-tablets were prepared using the system with the optimum dissolution profile and flowability. Tensile strengths, content uniformity and dissolution profiles of the mini-tablets were evaluated. The effects of different excipients and storage conditions on mini-tablet properties were also studied. The optimised rapid-release LOR mini-tablets were further evaluated for their in vivo pharmacokinetic profile. The co-evaporate of LOR with PLU showed significantly faster dissolution and superior flowability and was evaluated together with three directly compressible excipients (Cellactose® 80, StarLac® (STA) and Emcompress®) for mini-tablet formulation. The formulation with STA provided the optimum results in terms of tensile strength content uniformity and rapid drug release following a 3-month stability study and was selected for further in vivo evaluation. The pharmacokinetic profile indicated the potential of the mini-tablets achieving rapid release and increased absorption of LO

    30-day morbidity and mortality of sleeve gastrectomy, Roux-en-Y gastric bypass and one anastomosis gastric bypass: a propensity score-matched analysis of the GENEVA data

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    Background: There is a paucity of data comparing 30-day morbidity and mortality of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB). This study aimed to compare the 30-day safety of SG, RYGB, and OAGB in propensity score-matched cohorts. Materials and methods: This analysis utilised data collected from the GENEVA study which was a multicentre observational cohort study of bariatric and metabolic surgery (BMS) in 185 centres across 42 countries between 01/05/2022 and 31/10/2020 during the Coronavirus Disease-2019 (COVID-19) pandemic. 30-day complications were categorised according to the Clavien–Dindo classification. Patients receiving SG, RYGB, or OAGB were propensity-matched according to baseline characteristics and 30-day complications were compared between groups. Results: In total, 6770 patients (SG 3983; OAGB 702; RYGB 2085) were included in this analysis. Prior to matching, RYGB was associated with highest 30-day complication rate (SG 5.8%; OAGB 7.5%; RYGB 8.0% (p = 0.006)). On multivariate regression modelling, Insulin-dependent type 2 diabetes mellitus and hypercholesterolaemia were associated with increased 30-day complications. Being a non-smoker was associated with reduced complication rates. When compared to SG as a reference category, RYGB, but not OAGB, was associated with an increased rate of 30-day complications. A total of 702 pairs of SG and OAGB were propensity score-matched. The complication rate in the SG group was 7.3% (n = 51) as compared to 7.5% (n = 53) in the OAGB group (p = 0.68). Similarly, 2085 pairs of SG and RYGB were propensity score-matched. The complication rate in the SG group was 6.1% (n = 127) as compared to 7.9% (n = 166) in the RYGB group (p = 0.09). And, 702 pairs of OAGB and RYGB were matched. The complication rate in both groups was the same at 7.5 % (n = 53; p = 0.07). Conclusions: This global study found no significant difference in the 30-day morbidity and mortality of SG, RYGB, and OAGB in propensity score-matched cohorts

    30-Day morbidity and mortality of bariatric metabolic surgery in adolescence during the COVID-19 pandemic – The GENEVA study

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    Background: Metabolic and bariatric surgery (MBS) is an effective treatment for adolescents with severe obesity. Objectives: This study examined the safety of MBS in adolescents during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This was a global, multicentre and observational cohort study of MBS performed between May 01, 2020, and October 10,2020, in 68 centres from 24 countries. Data collection included in-hospital and 30-day COVID-19 and surgery-specific morbidity/mortality. Results: One hundred and seventy adolescent patients (mean age: 17.75 ± 1.30 years), mostly females (n = 122, 71.8%), underwent MBS during the study period. The mean pre-operative weight and body mass index were 122.16 ± 15.92 kg and 43.7 ± 7.11 kg/m2, respectively. Although majority of patients had pre-operative testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 146; 85.9%), only 42.4% (n = 72) of the patients were asked to self-isolate pre-operatively. Two patients developed symptomatic SARS-CoV-2 infection post-operatively (1.2%). The overall complication rate was 5.3% (n = 9). There was no mortality in this cohort. Conclusions: MBS in adolescents with obesity is safe during the COVID-19 pandemic when performed within the context of local precautionary procedures (such as pre-operative testing). The 30-day morbidity rates were similar to those reported pre-pandemic. These data will help facilitate the safe re-introduction of MBS services for this group of patients

    Man’s Politics Towards God: A Study in American and Iraqi Theatre Represented by Tony Kushner’s Angels in America: A Gay Fantasia on National Themes; Perestroika and Ali Abdul Nabi Azzaidi’s Ya Rab/Oh!God

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    Contemporary Theater is greatly influenced by the changes happening politically and socially all over the world. Man no longer looks for being part of a society or defining himself according to certain standards of tradition; he/she no longer search for their identity or feel suffocated by the new technology, his main concern in contemporary age is to redefine the identity away from politics and the judgmental eye of the society he is living in. Man is calling for resurrections of the god he admitted killing during the past millennium. A new perception of that god has been defined and this seems to be interesting in a world ruled by fighting sectors of extremists who are classified into two categories those who are against the rule of that god and those who are with. This paper examines the perception of that god in two different societies by two authors through studying their plays to explain how this theme is pictured by the two. The first is the American controversial playwright Tony Kushner who’s Angels In America: A Gay Fantasia on National Themes; Perestroika raised epic questions in this matter, the other playwright is the Iraqi dramatist Ali Abdul Nabi Azzaidi who’s play Ya Rab/Oh!God introduced a new trend in the Iraqi theater. The paper adopts a socio-political school of criticism to achieve its goals
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