7,861 research outputs found
A Halotolerant Bacterium Bacillus licheniformis HSW-16 Augments Induced Systemic Tolerance to Salt Stress in Wheat Plant (Triticum aestivum)
Certain plant growth promoting bacteria can protect associated plants from harmful effects of salinity. We report the isolation and characterization of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase bacterium Bacillus licheniformis HSW-16 capable of ameliorating salt (NaCl) stress in wheat plants. The bacterium was isolated from water of Sambhar salt lake, Rajasthan, India. The presence of ACC deaminase activity was confirmed by enzyme assay and analysis of AcdS gene, a structural gene for ACC deaminase. Inoculation of B. licheniformis HSW-16 protected wheat plants from growth inhibition caused by NaCl and increased plant growth (6-38%) in terms of root length, shoot length, fresh weight, and dry weight. Ionic analysis of plant samples showed that the bacterial inoculation decreased accumulation of Na+ content (51%), and increased K+ (68%), and Ca2+ content (32%) in plants at different concentration of NaCl. It suggested that bacterial inoculation protected plants from the effect of NaCl by decreasing level of Na+ in plants. Production of exopolysaccharide by the B. licheniformis HSW-16 can also protect from Na+ by binding this ion. Moreover, application of test isolate resulted in an increase in certain osmolytes such as total soluble sugar, total protein content and a decrease in malondialdehyde content, illustrating their role in the protection of plants. The ability of B. licheniformis HSW-16 to colonize plant root surface was examined by staining the bacterium with acridine orange followed by fluorescence microscopy and polymerase chain reaction (PCR)-based DNA fingerprinting analysis. These results suggested that B. licheniformis HSW-16 could be used as a bioinoculant to improve the productivity of plants growing under salt stress
Magnetization and Magneto-resistance in Y(Ba1-xSrx)2Cu3O7-{\delta} (x = 0.00 - 0.50) superconductor
Here we present the magnetic properties and upper critical field (BC2) of
polycrystalline Y(Ba1-xSrx)2Cu3O7-{\delta} superconductors, which are being
determined through detailed ac/dc susceptibility and resistivity under magnetic
field (RTH) study. All the samples are synthesized through solid state reaction
route. Reduction in Meissner fraction (the ratio of field cooled to zero field
cooled magnetization) is observed with increasing Sr content, suggesting
occurrence of flux pining in the doped samples. The ac susceptibility and
resistivity measurements reveal improved grain couplings in Sr substituted
samples. Consequently the inter-grain critical current density (Jc), upturn
curvature near the Tc in temperature dependence of upper critical field
[BC2(T)], and BC2 are enhanced. Both Jc and BC2 increase in lower Sr
substitution (up to x = 0.10) samples followed by decrease in higher doping due
to degradation in effective pining and grain coupling.Comment: 17 pages text + Figs, [email protected]
Optical Spectroscopy of Type Ia Supernovae
We present 432 low-dispersion optical spectra of 32 Type Ia supernovae (SNe
Ia) that also have well-calibrated light curves. The coverage ranges from 6
epochs to 36 epochs of spectroscopy. Most of the data were obtained with the
1.5m Tillinghast telescope at the F. L. Whipple Observatory with typical
wavelength coverage of 3700-7400A and a resolution of ~7A. The earliest spectra
are thirteen days before B-band maximum; two-thirds of the SNe were observed
before maximum brightness. Coverage for some SNe continues almost to the
nebular phase. The consistency of the method of observation and the technique
of reduction makes this an ideal data set for studying the spectroscopic
diversity of SNe Ia.Comment: Accepted for publication in the Astronomical Journal, 109 pages
(including data table), 44 figures, full resolution figures at
http://www.noao.edu/noao/staff/matheson/Iaspec.ps.g
Development of A Mathematical Model For Determining Temperature of A Lake Based on Climatic Variations and Its Validation Using Measured Data
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Relationship and Impact of Climatic Factors With Coastal Environmental Parameters (Water Temperature, Dissolved Oxygen) Due to Warm Water Discharge From A Proposed Power Plant
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
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