52 research outputs found

    Physiological alterations of Salvinia natans L. exposed to aluminium stress and its interaction with polyamine

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    In the present Investigation Salvinia natans L exposed to increasing concentration of Al stress and its interaction with polyamine was discussed. Among the physiological attributes Glutathione-S-transferase, glutathione peroxidase activities were up regulated against control. At transcript level glutathione peroxidase was also shown by over-expressed manner to support the lyses of peroxide. However, the application of Put had minimized these activities with same way to establish the role of polyamine under metal stress. In secondary metabolites synthetic pathway phenyl alanine ammonia lyase recorded a steady increase although the concentration of Al. Not only a single fraction of polyamine was responsible under Al stress but also pool of conjugated polyamine was up regulated. In oxidation of polyamine the activity of diamine oxidase (DAO) was more under metal stress to induce accumulation H2O2. In compensation for cellular depletion of reduced glutathione, dihydro ascorbate reductase activity was up regulated in plant under stress. At cellular level plants were distinctly marked with variations in heat shock proteins and established as a possible biomarker for Al toxicity. The study possibly established the affectivity in bio-monitoring of Al in field condition with exercise cellular responses of Salvinia plants

    Osmotin: A PR gene impart tolerance to excess salt in Indica Rice

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    Not AvailableAgrobacterium-mediated genetic transformation (strain: GV2260 harbouring osmotin gene in a binary vector pGV2260 under the transcription control of CaMV 35S promoter and Nos terminator) was restored to develop productive salt tolerant transgenic rice varieties in a well adaptive high yielding indica rice background of var. Ananda. Out of 705 calli transformed, 426 survived (60.44%) on kanamycin (50 mg/l) supplemented MS medium, which could regenerate 78 plantlets of which 56 survived from 29 independent transformation events. Molecular analyses showed 23 PCR positive, 9 Southern positive and 6 plants positive to both PCR and Southern hybridization. Southern hybridization with radio-labeled osmotin probe showed transgene integration in 2-6 loci in 6 representative transgenic plants. Seed germination test involving seeds at T1 generation on MS medium containing 50mg/l kanamycin showed 3:1 ratio for majority of the lines albeit with a few exception, might be due to small sample size or epistatic interactions. Tolerance test to excess salt was conducted invivoon artificially stimulated NaCl stress under hydroponics involving Hoagland solution showed progenies of T46-1 were most tolerant to excess NaCl followed by the progenies of T2-6, which were planted on soil in cement pots in the Transgenic Rearing Facility (Category II, DBT approved) till maturity and harvested seeds were kept plant wise for subsequent generation advancement of most productive lines with desirable salt tolerance for cultivation enmasseunder saline soil for enhanced productivity under constrained soil at sustainable-scale in Andaman Islands and elsewhere.Not Availabl

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    Not AvailableAmplified Fragment Length polymorphism (AFLP) was studied involving 48 diverse rice genotypes, comprising of indica, japonica, and Tongil type (indica × japonica) varieties to assess the genetic diversity. Initially 64 primer pair combinations were screened of which 5 were found to be suitable producing clear fragments (35–500 bp). In total 700 amplicons (bands) were produced with an average of 140 bands per primer pair. Maximum (207) from EcoRI AC*/MseI-CAC and minimum (75) amplicons from EcoRI TG*/MseI-CTT primer pairs were observed. Minimum (0.973) and maximum (0.990) PIC values recorded for primer pair EcoRI AC*/MseI-CAC and EcoRI AC*/MseI-CAT, respectively. Pairwise genetic similarity estimates ranged in between 0.6412 and 0.943 with a mean of 0.797. Triguna, an indica high yielding variety (HYV), and a new plant type (NPT) rice, IR 7946-46-1-3-2 having indica x japonica parentage showed minimum genetic similarity coefficient (0.641) with maximum genetic divergence, whereas ADT 41 and Sasyasree, two indica HYVs displayed maximum genetic similarity coefficient—0.953 with lowest genetic distance. All accessions could be clearly identified by using five primer pairs, offers immense scope of AFLP in assessing genetic diversity in rice. The present study also identified prospective varieties for use in selective hybridization and productive progeny selection. Most of the varieties shared distinct clusters based on varietal types, race, parentage and growing area where those are cultivated traditionally albeit with a few exceptions. The dendrogram could demarcate the varieties irrespective of race with unique traits, albeit with exceptions, which warrants further experimentation involving more number of primers in future.Not Availabl

    Curcumin in Reverse Micelle: An Example to Control Excited-State Intramolecular Proton Transfer (ESIPT) in Confined Media

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    In this Article, we focused on the modulation of the photophysical properties of curcumin, an anti-cancer drug, in aqueous and nonaqueous reverse micelles of AOT in <i>n</i>-heptane using steady-state and time-resolved fluorescence spectroscopy. The instability of curcumin is a common problem which restricts its numerous applications like Alzheimer disease, HIV infections, cystic fibrosis, etc. Our study reveals that curcumin shows comparatively higher stability after encapsulation into the interfacial region of the reverse micelle. To get a vivid description of the microenvironment, we added hydrogen-bond-donor (HBD) as well as no<i>n</i>-hydrogen-bond-donor (NBD) core solvents. For experimental purposes, we used water, ethylene glycol (EG), glycerol (GY) as HBD solvents and <i>N</i>,<i>N</i>-dimethyl formamide (DMF) as a NBD solvent. With increasing amount of core solvents, irrespective of HBD or NBD, the fluorescence intensity and lifetime of curcumin increase with remarkable red-shift inside the reverse micelle. This is attributed to the modulation of the nonradiative rates associated with the excited-state intermolecular hydrogen bonding between the pigment and the polar solvents. We obtained a high partition constant at <i>W</i><sub>0</sub> = 0 (<i>W</i><sub>0</sub> = [core solvent]/[AOT]) which is certainly due to the hydrogen bonding between the negatively charged sulfonate group of AOT and hydroxyl groups of curcumin. Steady-state anisotropy and time-resolved results give an idea about the microenvironment sensed by the curcumin molecules. The red-shift of emission spectra, increase in the value of <i>E</i><sub>T</sub>(30), as well as the increase in the fluorescence lifetime were interpreted as being caused by the partition of the probe between the micellar interface and the polar core solvent. Indeed, we show here that it is possible to control the excited state intramolecular proton transfer (ESIPT) process of curcumin by simply changing the properties of the AOT reverse micelle interfaces by choosing the appropriate polar solvents to make the reverse micelle media

    Dendritic Cell-Based Immunotherapy Combined with Antimony-Based Chemotherapy Cures Established Murine Visceral Leishmaniasis

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    Dendritic cells (DCs) have been proposed to play a critical role as adjuvants in vaccination and immunotherapy. In this study we evaluated the combined effect of soluble Leishmania donovani Ag (SLDA)-pulsed syngeneic bone marrow-derived DC-based immunotherapy and antimony-based chemotherapy for the treatment of established murine visceral leishmaniasis. Three weekly injections of SLDA-pulsed DCs into L. donovani-infected mice reduced liver and splenic parasite burden significantly, but could not clear parasite load from these organs completely. Strikingly, the conventional antileishmanial chemotherapy (sodium antimony gluconate) along with injections of SLDA-pulsed DCs resulted in complete clearance of parasites from both these organs. Repetitive in vitro stimulation of splenocytes from uninfected or L. donovani-infected mice with SLDA-pulsed DCs led to the emergence of CD4� T cells with characteristics of Th1 cells. Our data indicate that DC-based immunotherapy enhances the in vivo antileishmanial potential of antimony or vice versa

    Spontaneous Transition of Micelle–Vesicle–Micelle in a Mixture of Cationic Surfactant and Anionic Surfactant-like Ionic Liquid: A Pure Nonlipid Small Unilamellar Vesicular Template Used for Solvent and Rotational Relaxation Study

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    The micelle–vesicle–micelle transition in aqueous mixtures of the cationic surfactant cetyl trimethyl ammonium bromide (CTAB) and the anionic surfactant-like ionic liquid 1-butyl-3-methylimidazolium octyl sulfate, [C<sub>4</sub>mim]­[C<sub>8</sub>SO<sub>4</sub>] has been investigated by using dynamic light scattering (DLS), transmission electron microscopy (TEM), surface tension, conductivity, and fluorescence anisotropy at different volume fractions of surfactant. The surface tension value decreases sharply with increasing CTAB concentration up to ∼0.38 volume fraction and again increases up to ∼0.75 volume fraction of CTAB. Depending upon their relative amount, these surfactants either mixed together to form vesicles and/or micelles, or both of these structures were in equilibrium. Fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH), incorporated in this system at different composition of surfactant indicates the formation of micelle and vesicle structures. The apparent hydrodynamic diameter of these large multilamellar vesicles is about ∼200 nm–300 nm obtained by DLS measurement and finally confirmed by TEM micrographs. The large multilamellar vesicles are transformed into small unilamellar ones by sonication using a Lab-line instruments probe sonicator with a diameter of ∼90–125 nm. To investigate the heterogeneity, solvent, and rotational relaxation of coumarin-153 (C-153) have been investigated in these unilamellar vesicles by using picosecond time-resolved fluorescence spectroscopic technique. The solvation dynamics of C-153 in these vesicles is found to be biexponential with average time constant ∼580 ps. This indicates the slow relaxation of water molecules in the surfactant bilayer. In accordance with solvation dynamics, fluorescence anisotropy analysis of C-153 in unilamellar vesicles also indicates hindered rotation compared to bulk water
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