Foliar Spray with 24-Epibrassinolide Enhanced Strawberry Fruit Quality,Phytochemical Content,and Postharvest Life

Journal of Plant Growth Regulation - Activation of complex metabolic pathways and antioxidant activities is necessary for enhancing quality and health promoting capacity of food crops. Plant growth...     

Conjugated Antisense Oligonucleotides for Inhibition of Human Cytomegalovirus In Vitro

Abstract

Several thiono triester containing oligonucleotide phosphorothioates linked with a lipophilic group have been synthesized. Some of these modified antisense oligonucleotides show potent anti-HCMV activity as well as improved cellular association and nuclease resistance.     

Nuclear magnetic resonance investigation of lysine–oligopeptides and a complex with d(pA)3pGpC(pT)3

We report proton magnetic resonance studies of a series of lysine oligopeptides in H₂O solution. At pH 5 the protonated ε-amino groups are seen as broad resonances; the peptide NH proton resonances are split by spin–spin coupling with the C^α-H proton, and appear at positions which depend on position in the chain and on chain length. Assignments were made by the europium shift method, and we observed the expected effect of catalysis by the terminal —NH₃⁺ of exchange of the adjacent peptide NH. Coupling constants and the temperature coefficient of chemical shift values were consistent with a non-hydrogen-bonded structure for the oligolysines. The rate and mechanism of NH hydrogen exchange were investigated by line-broadening measurements of the peptide protons as a function of pH. Exchange was found to be OH^? catalyzed, with large differences in the rate depending on position in the chain. Preliminary studies of the complex between double-helical d(pA)₃pGpC(pT)₃ and tetra(L -lysine) were performed using ¹H- and ³¹P-nmr techniques. Pmr spectra of the complex at pH values ranging from 3.98 to 8.15 showed very complicated patterns. Downfield shifts and reduction in exchange rates were observed for several tetra(L -lysine) protons. ³¹P-nmr spectra of the complex reveal an upfield shift of 1 ppm for 3′-5′ phosphate diester resonances on complexation. ³¹P T₁ relaxation times change little on complex formation at low temperature but are altered at higher temperature.     

Antioxidant role of coumarin on streptozotocin-nicotinamide-induced type 2 diabetic rats

The purpose of this study was to investigate the antioxidant role of coumarin on streptozotocin-nicotinamide-induced Type 2 diabetic rats. In experimental rats, the levels of plasma glucose, insulin, and the levels of thiobarbituric acid reactive substances, lipid hydroperoxides, conjugated dienes, and the activities of superoxide dismutase, catalase, glutathione-S-transferase, and glutathione peroxidase were assayed in liver and kidney. Diabetic rats showed elevated levels of plasma glucose and lipid peroxidation markers and reduced plasma insulin and antioxidant enzymes. Oral administration of coumarin resulted in a significant reduction in the plasma glucose and lipid peroxides and a significant increase in the plasma insulin and antioxidant enzymes. Chronic treatment of coumarin remarkably restored the normal status of the histopathological changes observed in the selected tissues. It can be concluded that coumarin has antioxidant effect in Type 2 diabetic rats.     

A novel role for catalase B in the maintenance of fungal cell-wall integrity during host invasion in the rice blast fungus Magnaporthe grisea

Asexual spores of the rice blast fungus germinate to produce a specialized and melanized infection structure, the appressorium, which is pivotal to successful plant penetration. To investigate whether Magnaporthe grisea counteracts the toxic burst of H2O2 localized beneath the site of attempted invasion, we examined the temporal expression of five candidate antioxidant genes. Of these, the putatively secreted large subunit catalase CATB gene was 600-fold up-regulated in vivo, coincident with penetration, and moderately up-regulated in vitro, in response to exogenous H2O2. Targeted gene replacement of CATB led to compromised pathogen fitness; the catB mutant displayed paler pigmentation and accelerated hyphal growth but lower biomass, poorer sporulation, fragile conidia and appressoria, and impaired melanization. The catB mutant was severely less pathogenic than Guy 11 on barley and rice, and its infectivity was further reduced on exposure to H2O2. The wild-type phenotype was restored by the reintroduction of CATB into the catB mutant We found no evidence to support a role for CATB in detoxification of the host-derived H2O2 at the site of penetration. Instead, we demonstrated that CATB plays a part in strengthening the fungal wall, a role of particular importance during forceful entry into the host.     

Gene microarray analysis using angular distribution decomposition.

Clustering techniques have been widely used in the analysis of microarray data to group genes with similar expression profiles. The similarity of expression profiles and hence the results of clustering greatly depend on how the data has been transformed. We present a method that uses the relative expression changes between pairs of conditions and an angular transformation to define the similarity of gene expression patterns. The pairwise comparisons of experimental conditions can be chosen to reflect the purpose of clustering allowing control the definition of similarity between genes. A variational Bayes mixture modeling approach is then used to find clusters within the transformed data. The purpose of microarray data analysis is often to locate groups genes showing particular patterns of expression change and within these groups to locate specific target genes that may warrant further experimental investigation. We show that the angular transformation maps data to a representation from which information, in terms of relative regulation changes, can be automatically mined. This information can be then be used to understand the "features" of expression change important to different clusters allowing potentially interesting clusters to be easily located. Finally, we show how the genes within a cluster can be visualized in terms of their expression pattern and intensity change, allowing potential target genes to be highlighted within the clusters of interest.