Cold-induced physiological and biochemical responses of three grapevine cultivars differing in cold tolerance

In this study the cold tolerance potential of three Vitis vinifera cultivars including ‘Red Sultana’, ‘White Sultana,’ and ‘Flame Seedless’ was evaluated under greenhouse condition. After 15 leaves stage in average, the grapevine plants were subjected to cold stress regimes (4, 0 and ? 4 °C) and compared with control plants (24 °C). A clear increase in leaf electrolyte leakage (EL), thiobarbituric acid reactive substances (TBARS), and H₂O₂ concentrations was observed with decreasing temperature from 4 to ? 4 °C in all grapevine cultivars. Chilled plants showed marked increases in their abscisic acid (ABA), soluble sugars, and proline contents in compared to control vines. Upon exposure to cold stress, the EL, TBARS, H₂O₂, and relative water content of ‘Red Sultana’ were found to be lower compared to ‘White Sultana’ and ‘Flame Seedless’. Under 0 °C condition, ‘Red Sultana’ had the highest superoxide dismutase, guaiacol peroxidase and catalase activities, which was approximately twofold higher than those of all other cultivars. Soluble sugars such as glucose, fructose, and sucrose increased from 4 to ? 4 °C. These increments were higher in ‘Red Sultana’ compared to other cultivars which was concomitant with higher accumulation of endogenous ABA concentration in this cultivar. Higher accumulation of ABA and soluble sugars in ‘Red Sultana’ confirmed the key roles of these compounds in cold tolerance which could be applied as a cold tolerance marker for early selection of grapevine cultivars with the aim to establish vineyards in cold winter regions.     

Large-scale purification of recombinant hepatitis B surface antigen from Pichia pastoris with non-affinity chromatographic methods as a substitute to immunoaffinity chromatography

Abstract

The costly media, inconsistent ligand density, ligand leakage, and possible destabilization of recombinant hepatitis B surface antigen (rHBsAg) particles are main drawbacks of using immunoaffinity chromatography (IAF) in the large-scale downstream processing. In this study, we aimed to use an efficient large-scale purification system as an alternative purification method for immunoaffinity chromatography. For this purpose, we suggested integrating non-affinity chromatographic methods of hydrophobic interaction chromatography (HIC) and size-exclusion chromatography (SEC) for cost-effective purification of rHBsAg expressed in P. pastoris. The optimization of such process is not trivial and straightforward since diverse molecular characteristics of expressed rHBsAg in each type of host cell cause different interactions in non-affinity chromatography processes. The working buffer composition and chromatography parameters are the most influential factors in hydrophobic interaction chromatography. The best result for lab-scale HIC was achieved by using ammonium sulfate buffer in 10% of saturation concentration in pH 7.0 with Butyl-S Sepharose 6 Fast Flow medium and with subsequent Tween-100 and urea elution. In this process, the recovery, purity, and total yield were about 84%, 82%, and 69%, respectively. By scaling-up the HIC and integrating it with Sephacryl S-400?SEC, we obtained highly pure, i.e.,?>?90%, rHBsAg virus-like particles (VLP).     

Wnt lipidation: Roles in trafficking,modulation, and function

The Wnt signaling pathway consists of various downstream target proteins that have substantial roles in mammalian cell proliferation, differentiation, and development. Its aberrant activity can lead to uncontrolled proliferation and tumorigenesis. The posttranslational connection of fatty acyl chains to Wnt proteins provides the unique capacity for regulation of Wnt activity. In spite of the past belief that Wnt molecules are subject to dual acylation, it has been shown that these proteins have only one acylation site and undergo monounsaturated fatty acylation. The Wnt monounsaturated fatty acyl chain is more than just a hydrophobic coating and appears to be critical for Wnt signaling, transport, and receptor activation. Here, we provide an overview of recent findings in Wnt monounsaturated fatty acylation and the mechanism by which this lipid moiety regulates Wnt activity from the site of production to its receptor interactions.     

Chaperone-like activity of α-cyclodextrin via hydrophobic nanocavity to protect native structure of ADH

The chaperone action of α-cyclodextrin (α-CyD), based on providing beneficial microenvironment of hydrophobic nanocavity to form molecular complex with alcohol dehydrogenase (ADH) was examined by experimental and computational techniques. The results of UV-vis and dynamic light scattering (DLS) indicated that the chaperone-like activity of α-CyD depends on molecular complex formation between α-CyD and ADH, which caused to decrease the amount and size of polymerized molecules. Computational calculations of molecular dynamic (MD) simulations and blind docking (BD) demonstrated that α-CyD acts as an artificial chaperone because of its high affinity to the region of ADH’s two chains interface. The hydrophobic nanocavity of α-CyD has the ability to form inclusion complex due to the presence of phenyl ring of aromatic phenylalanine (Phe) residue in the dimeric intersection area. Delocalization of ADH subunits, which causes the exposure of Phe110, takes part in the enzyme polymerization and has proven to be beneficial for aggregation inhibition and solubility enhancement within the host α-CyD-nanocavity.     

Association and impact of <Emphasis Type="Italic">XPG Asp</Emphasis> 1104 <Emphasis Type="Italic">His</Emphasis> gene polymorphism in HIV 1 disease progression to AIDS among north Indian HIV seropositive individuals

Various efforts made to stop the deadly epidemic of HIV since its discovery in 1983 remain unsuccessful and this virus still continues to claim the lives of millions of individuals every year. The viral effect in the cell is complicated and the overall disease outcome is the result of interaction between a few viral proteins and complex host immune response. Because it has been reported that XPG (Xeroderma pigementesum group G) gene does play a role in reducing UV induced apoptosis and participate in Nucleotide Excision Repair (NER) process of DNA damage, it was hypothesized that polymorphism in this gene may have a role in HIV 1 disease progression to AIDS. The aim of the present study, therefore, was to find out the association between XPG gene polymorphism and its effect on the rate of HIV 1 disease progression to AIDS. 300 HIV seropositive cases and an equal number of age and sex matched controls were recruited for the study from north Indian population. The PCR-RFLP method was utilized to genotype 600 study subject for the XPG Asp ¹¹⁰⁴ His gene polymorphism. There was significant difference in the frequency of the His/His variant genotype (OR 1.95, 95% CI = 1.93–3.63, P = 0.04) between cases and controls indicating a probable role of this gene in host viral interactions.     

Experimental infection of house finches with Mycoplasma gallisepticum

Mycoplasma gallisepticum (MG) has caused an endemic upper respiratory and ocular infection in the eastern house finch (Carpodacus mexicanus) after the epidemic first described in 1994. The disease has been studied by a number of investigators at a population level and reports describe experimental infection in group-housed MG-free house finches. Because detailed observation and evaluation of individual birds in group-housed passerines is problematic, we studied individually housed house finches that were experimentally inoculated with the finch strain of MG in a controlled environment. To accomplish this, a study was conducted spanning the period of November 2001-April 2002 with 20 MG-free (confirmed by the rapid plate agglutination assay and polymerase chain reaction [PCR] assay) eastern house finches captured in the Cayuga Basin area of central New York (USA) in the summer of 2001. After a period of acclimatization and observation (12 wk), 20 finches were inoculated with a 0.05-ml aliquot of MG (3.24 x 10(5) colony-forming units/ml) via bilateral conjunctival sac instillations. Two additional finches acted as controls and were inoculated in the same manner with preservative-free sterile saline solution. After inoculation, all finches except the controls exhibited clinical signs of conjunctivitis within 2-6 days. The progression of the disease was evaluated by several methods, including PCR, behavioral observations, and physical examination including eye scoring, body weight, and body condition index. Over a period of 21 wk, MG-infected finches developed signs of disease and recovered (80%), developed signs of disease and progressed to become chronically infected (15%), or died (5%). We hypothesize that the high survival rate and recovery of these finches after infection was associated with the use of controlled environmental conditions, acclimatization, a high plane of nutrition, and low stocking (housing) density, all of which are factors documented to be important in the outcome of MG infections in domestic poultry and other species.     

Modulation of rat granulocyte traffic by a surface active agent in vitro and bleomycin injury

Pluronic F68 (F68) is a nonionic surfactant which has been reported to inhibit the in vitro adherence and migration of polymorphonuclear leukocytes (PMN) obtained from some species. We demonstrated similar effects on PMN obtained from rats, with diminished adherence to nylon wool and diminished chemotaxis toward zymosan-activated serum. We then examined the in vivo effects of 12-hr F68 infusion on the injury induced by intratracheal bleomycin instillation (ITB) in rats. When sacrificed 24 hr following injury, rats demonstrated neutrophilia, neutrophil-prominent lung lavage cellularity, and increased lung weights. F68 decreased lavage leukocyte counts and lung weight gain in ITB-injured animals. Lung weights of ITB-injured animals correlated (r = 0.81, P less than 0.001) with logarithmic values of lavage PMN. F68 also enhanced neutrophilia and decreased spleen weight gain in injured animals. The acute effects of F68 on circulating leukocyte counts, osmolality, and total complement were also examined. The data demonstrate that F68 can affect PMN traffic both in vitro and in vivo. The data also confirm the prominence of PMN in lavage fluid early in ITB injury, and suggest that an influx of relatively few PMN is associated with lung weight gain in this model.     

Genetic diversity and vector transmission of phytoplasmas associated with sesame phyllody in Iran

During 2010–14 surveys in the major sesame growing areas of Fars, Yazd and Isfahan provinces (Iran), genetic diversity and vector transmission of phytoplasmas associated with sesame phyllody were studied. Virtual RFLP, phylogenetic, and DNA homology analyses of partial 16S ribosomal sequences of phytoplasma strains associated with symptomatic plants revealed the presence of phytoplasmas referable to three ribosomal subgroups, 16SrII-D, 16SrVI-A, and 16SrIX-C. The same analyses using 16S rDNA sequences from sesame phyllody-associated phytoplasmas retrieved from GenBank database showed the presence of phytoplasmas clustering with strains in the same subgroups in other Iranian provinces including Bushehr and Khorasan Razavi. Circulifer haematoceps and Orosius albicinctus, known vectors of the disease in Iran, were tested for transmission of the strains identified in this study. C. haematoceps transmitted 16SrII-D, 16SrVI-A, and 16SrIX-C phytoplasmas, while O. albicinctus only transmitted 16SrII-D strains. Based on the results of the present study and considering the reported presence of phytoplasmas belonging to the same ribosomal subgroups in other crops, sesame fields probably play an important role in the epidemiology of other diseases associated with these phytoplasmas in Iran.     

A genetic assay of three patients in the same family with Holt-Oram syndrome; a case report

Holt-Oram syndrome (HOS) is a developmental disorder inherited in an autosomal-dominant pattern. Affected organs are the heart and forelimbs with upper extremity skeletal defects and congenital heart malformation. In this study we present three cases of HOS in the same family. In one of these three individuals we detected a transition of C to T (CTG-GTT, V205V) in exon 7 of the TBX5 gene. This nucleotide change causes no amino acid change and potential pathologic effects remain unknown.Key Words: Holt-Oram syndrome, Congenital heart malformation, TBX5 gene