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141.
A halotolerant plant-growth-promoting rhizobacteria (PGPR) can ameliorate salt stress in associated plants by various mechanisms. Therefore, the present study aimed to characterize a PGPR Klebsiella sp. SBP-8 for its ability to tolerate salt stress and to study the mechanism of PGPR-mediated mitigation of salt stress in the wheat plant. The abiotic stressors result in multiple changes in the fatty acid composition of Klebsiella sp. SBP-8, helping the membrane to keep its integrity, fluidity, and function for its growth under salt (NaCl) stress conditions. The changes in fatty acid composition of test organism were analyzed by fatty acid methyl ester (FAME) analysis under varying saline conditions. The spectroscopy (GC-MS) profile of cell extract at different salt concentrations was comprised of hydrocarbons, and fatty alcohols with varying carbon chain length. Inoculation of Klebsiella sp. SBP-8 to wheat seedling showed increase in proline, total soluble sugar, and total protein content of treated plants. Bacterial inoculation also decreased the concentration of salinity-induced malondialdehyde (MDA) content. In addition, bacterial inoculation also increased the various antioxidative enzymes like superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX) in treated plants. It is likely that bacterial inoculation alleviated the salt stress to wheat plant by co-ordination of antioxidative machinery, and improvement in osmolyte contents. Therefore, the present study suggests that bacterial-inoculated wheat plants were able to cope better with salt stress than uninoculated control, therefore it can serve as a promising bio-inoculant for enhancing the growth of wheat like cereal crops under saline stress. 相似文献
142.
143.
Singh Rajnish Prakash Jha Prameela Jha Prabhat Nath 《Journal of Plant Growth Regulation》2017,36(3):783-798
Journal of Plant Growth Regulation - Bacteria residing in the rhizosphere and capable of host plant growth stimulation (PGPR) through ACC-deaminase activity can ameliorate various biotic- and... 相似文献
144.
Kumar Srivastava B Soni R Patel JZ Jha S Shedage SA Gandhi N Sairam KV Pawar V Sadhwani N Mitra P Jain MR Patel PR 《Bioorganic & medicinal chemistry letters》2008,18(14):3882-3886
Facile synthesis of biaryl pyrazole sulfonamide derivative of 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxylic acid piperidin-1-ylamide (SR141716, 1) and an investigation of the effect of replacement of the –CO group in the compound 1 by the –SO2 group in the aminopiperidine region is reported. Primary ex-vivo pharmacological testing and in vitro screening of sulfonamide derivative 2 showed the loss of CB1 receptor antagonism. 相似文献
145.
Vikash Sewram Ndumiso Mshicileli Gordon S. Shephard Walter F. O. Marasas 《Biomarkers》2003,8(2):110-118
This study shows for the first time the accumulation of fumonisin mycotoxins in human hair of population clusters exposed to contaminated maize, and thus the feasibility of human hair analysis for the assessment of past fumonisin exposure. Composite hair samples were obtained from the Bizana, Butterworth and Centane districts within the Transkei region of the Eastern Cape Province of South Africa. Following methanol extraction and strong anion exchange clean up, the fumonisins FB1, FB2 and FB3 were detected using high performance liquid chromatography coupled to electrospray ionization-mass spectrometry (HPLC-ESI-MS). Hair from Centane and Butterworth showed mean levels of FB1 of 26.7 and 23.5 μg kg-1 hair, respectively. FB2 was only detected in hair from Centane and in one sampling point in Butterworth, with mean levels of 6.5 and 5.7 μg kg-1 hair, respectively. Hair samples from Bizana, on the other hand, were found to contain higher levels of FB 1 (mean 33.0 μg kg-1 hair) and FB 2 (mean 11.1 μg kg-1 hair). No samples contained more than trace levels of FB 3 . Recoveries from spiked hair samples using this method ranged from 81% to 101%, demonstrating the applicability of hair analysis in assessing human exposure to fumonisin mycotoxins. 相似文献
146.
Archana Jha 《Biophysical journal》2009,96(10):4075-4084
We studied single-channel currents from neuromuscular acetylcholine receptor-channels with mutations in the pore-lining, M2 helix of the ɛ-subunit. Three parameters were quantified: 1), the diliganded gating equilibrium constant (E2), which reflects the energy difference between C(losed) and O(pen) conformations; 2), the correlation between the opening rate constant and E2 on a log-log scale (Φ), which illuminates the energy character of the residue (C- versus O-like) within the C↔O isomerization process; and 3), the open-channel current amplitude (i0), which reports whether a mutation alters the energetics of ion permeation. The largest E2 changes were observed in the cytoplasmic half of ɛM2 (5′, 9′, 12′, 13′, and 16′), with smaller changes apparent for residues ≥17′. Φ was ∼0.54 for most ɛM2 residues, but was ∼0.32 at the positions that had largest E2 changes. An arginine substitution reduced i0 significantly at six positions, with the magnitude of the reduction increasing, 16′→2′. The measurements suggest that the 9′, 12′, and 13′ residues experience large and late free-energy changes in the channel-opening process. We speculate that in the gating isomerization the pore-facing residues >6′ and <16′ experience multiple energy perturbations associated with changes in protein structure and, perhaps, hydration. 相似文献
147.
The Comet Assay or single cell gel electrophoresis assay is one of the very widely used assays to microscopically detect DNA
damage at the level of a single cell. The determination of damage is carried out either through visual scoring of cells (after
classification into different categories on the basis of tail length and shape) or by using different commercially available
or public domain software (which automatically recognise the extent of damage). In this assay, the shape, size and amount
of DNA within the ‘comet’ play important roles in the determination of the level of damage. The use of a software in particular
also provides a range of different parameters, many of which might not be relevant in determining the extent of DNA damage.
As a large number of factors could influence the shape, size, identification and determination of induced damage, which includes
the scoring criteria, staining techniques, selection of parameters (whilst using the software packages) and appearance of
‘hedgehog’ or ‘clouds’, this article aims (a) to provide an overview of evolution of measurements of DNA damage using the
Comet Assay and (b) to summarise and critically analyse the advantages and disadvantages of different approaches currently
being adopted whilst using this assay. It is suggested that judicious selection of different parameters, staining methods
along with inter-laboratory validation and harmonisation of methodologies will further help in making this assay more robust
and widely acceptable for scientific as well as regulatory studies. 相似文献
148.
149.
The neuronal dynamin1 functions in the release of synaptic vesicles by orchestrating the process of GTPase-dependent membrane fission. Dynamin1 associates with the plasma membrane–localized phosphatidylinositol-4,5-bisphosphate (PIP2) through the centrally located pleckstrin homology domain (PHD). The PHD is dispensable as fission (in model membranes) can be managed, even when the PHD-PIP2 interaction is replaced by a generic polyhistidine- or polylysine-lipid interaction. However, the absence of the PHD renders a dramatic dampening of the rate of fission. These observations suggest that the PHD-PIP2–containing membrane interaction could have evolved to expedite fission to fulfill the requirement of rapid kinetics of synaptic vesicle recycling. Here, we use a suite of multiscale modeling approaches to explore PHD–membrane interactions. Our results reveal that 1) the binding of PHD to PIP2-containing membranes modulates the lipids toward fission-favoring conformations and softens the membrane, and 2) PHD associates with membrane in multiple orientations using variable loops as pivots. We identify a new loop (VL4), which acts as an auxiliary pivot and modulates the orientation flexibility of PHD on the membrane—a mechanism that we believe may be important for high-fidelity dynamin collar assembly. Together, these insights provide a molecular-level understanding of the catalytic role of PHD in dynamin-mediated membrane fission. 相似文献
150.
Tapan K. Chaudhuri Vikash K. Verma Aditi Maheshwari 《Progress in biophysics and molecular biology》2009,99(1):42-50
Escherichia coli chaperonins GroEL and GroES are indispensable for survival and growth of the cell since they provide essential assistance to the folding of many newly translated proteins in the cell. Recent studies indicate that a substantial portion of the proteins involved in the host pathways are completely dependent on GroEL–GroES for their folding and hence providing some explanation for why GroEL is essential for cell growth. Many proteins either small-single domain or large multidomains require assistance from GroEL–ES during their lifetime. Proteins of size up to 70 kDa can fold via the cis mechanism during GroEL–ES assisted pathway, but other proteins (>70 kDa) that cannot be pushed inside the cavity of GroEL–ATP complex upon binding of GroES fold by an evolved mechanism called trans. In recent years, much work has been done on revealing facts about the cis mechanism involving the GroEL assisted folding of small proteins whereas the trans mechanism with larger polypeptide substrates still remains under cover. In order to disentangle the role of chaperonin GroEL–GroES in the folding of large E. coli proteins, this review discusses a number of issues like the range of large polypeptide substrates acted on by GroEL. Do all these substrates need the complete chaperonin system along with ATP for their folding? Does GroEL act as foldase or holdase during the process? We conclude with a discussion of the various queries that need to be resolved in the future for an extensive understanding of the mechanism of GroEL mediated folding of large substrate proteins in E. coli cytosol. 相似文献