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This study investigates the potential of natural products derived from a mangrove rhizosphere bacterium in tomato early blight management. A Streptomyces puniceus strain L75 was isolated from the rhizosphere of Acanthus ilicifolius Linn in the Mai Po Reserve, Hong Kong. The crude ethyl acetate (EA) extract of L75 fermentation cultures has broadspectrum antifungal bioactivities. L75 EA extract was significantly more effective in Alternaria solani growth inhibition at 25 pg/ml or lower compared with Mancozeb, with no observable negative impacts on tomato leaves or root development. Furthermore, L75 EA extract had significantly lower aquatic toxicity than Mancozeb at the same concentrations. L75 EA extract targets germ tube elongation of A. solani conidia, with a fungistatic mode of action. Liquid chromatographyquadrupole time-of-flight mass spectrometry analysis identified two possible antifungal compounds, Alteramide A and the Heat-Stable Antifungal Factor, which together conuibute partially to the bioactivity of L75 EA extract. On detached tomato leaves, coinoculation of A. solani with L75 EA extract of 50, 25, or 5 pg/ml reduced diseased areas by --98, --90, and --48%, respectively, relative to the control after 5 days. This study demonstrates the potential of natural products from mangrove rhizosphere bacteria in agricultural applications. [ABSTRACT FROM AUTHOR]

The effects of tumorigenic and nontumorigenic strains of Agrobacterium vitis on graft strength and growth of grapevines was studied. A procedure was developed for inoculating graft interface surfaces with A. vitis and for measuring the force required to break grafts at different time points. Cuttings were soaked in an aqueous suspension of bacteria, about 106 CFU/ml, and bacteria were spread onto the graft interface during the grafting procedure. Tumorigenic strain CG49 caused reduced bud germination and increased callus (crown gall) at the graft union and at the base of cuttings at 30 days postinoculation (dpi) and significantly reduced shoot growth by 60 dpi whereas, at the same time points, nontumorigenic strain F2/5 inhibited callus formation but did not affect bud germination or shoot growth. Graft strength was enhanced at 30 dpi with CG49, presumably because the crown gall callus served to secure the union; graft strength was weakened by F2/5 over the same period. Between 30 and 60 dpi, the greatest increase in graft strength was observed in the water control. Following graft union inoculations, the A. vitis population increased more than 1,000-fold within 5 days. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) can regulate signaling pathways via S-nitrosylation. Fyn can be post-translationally modified in many biological processes. In the present study, using a rat four-vessel-occlusion ischemic model, we aimed to assess whether Fyn could be S-nitrosylated and to evaluate the effects of Fyn S-nitrosylation on brain damage. In vitro, Fyn could be S-nitrosylated by S-nitrosoglutathione (GSNO, an exogenous NO donor), and in vivo, endogenous NO synthesized by NO synthases (NOS) could enhance Fyn S-nitrosylation. Application of GSNO, 7-nitroindazole (7-NI, an inhibitor of neuronal NOS) and hydrogen maleate (MK-801, the N-methyl-D-aspartate receptor (NMDAR) antagonist) could decrease the S-nitrosylation and phosphorylation of Fyn induced by cerebral ischemia/reperfusion (I/R). Cresyl violet staining validated that these compounds exerted neuroprotective effects against the cerebral I/R-induced damage to hippocampal CA1 neurons. Taken together, in this study, we demonstrated that Fyn can be S-nitrosylated both in vitro and in vivo and that inhibiting S-nitrosylation can exert neuroprotective effects against cerebral I/R injury, potentially via NMDAR-mediated mechanisms. These findings may lead to a new field of inquiry to investigate the underlying pathogenesis of stroke and the development of novel treatment strategies. [ABSTRACT FROM AUTHOR]

It is reported in this paper that a microsized magnetic particle Fe3O4with peanutlike morphology is successfully prepared from FeCO3with the same morphology via direct-sealed thermal decomposition. The peanutlike FeCO3is obtained by hydrothermal reaction of the mixed aqueous solution containing Fe3and CO32-in the presence of ascorbic acid. The dynamic formation process of the FeCO3precursor and influence of reaction conditions on the FeCO3morphology are discussed in detail. The results show that both concentrations of ascorbic acid and Fe3in the reactive system play critical roles in obtaining peanutlike morphology. With this method, other microsized Fe3O4or Fe2O3with ellipsoidal, ellipsoidal rods, or rodlike morphologies could also be developed. [ABSTRACT FROM AUTHOR]

One-step synthesis of carbon-encapsulated Fe3O4core/shell composites is reported. The Fe3O4cores were formed via the reduction of Fe3+by glucose under alkaline conditions obtained by the decomposition of urea. The amorphous carbon shells were carbonized from glucose. A possible formation mechanism for the Fe3O4@C composite was discussed. In order to characterize these Fe3O4@C core-shell composites, high-resolution transmission electron microscopy (HR-TEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), x-ray photoelectron spectroscopy (XPS) and a superconducting quantum interference device (SQUID) magnetometer were employed to characterize the sample obtained using the above method. [ABSTRACT FROM AUTHOR]