Evidence of regulation of calcium uptake by phytochrome in maize protoplasts

Red light stimulated calcium uptake in maize leaf protoplasts upto 140% over the dark control. The stimulation was maximally noticed after 120 seconds of incubation and was reversed by far red light. 5-Hydroxytryptamine also enhanced calcium uptake in dark, upto the red level. A possible role of phosphoinositide for signal transduction in calcium uptake for phytochrome mediated responses in higher plants is suggested.     

Genotoxicity of 'gudakhu', a tobacco preparation. I. In mice in vivo.

'Gudakhu' is a paste-like tobacco preparation used widely in Orissa and neighbouring states of India. During use it is rubbed over the teeth and gum with a finger tip. Besides tobacco, it contains molasses, lime, red soil and water. The genotoxic potential of acetone extract of gudakhu was evaluated in mice in vivo using the chromosome aberration assay, micronucleus test and SCE analysis following single as well as long-term repeated treatment. The animals received an aqueous suspension of the extract via the oral route. Gudakhu extract induced significantly high frequencies, compared to controls, of chromosome aberrations, micronuclei (MN) and SCEs. Single treatment with different doses clearly revealed a distinct dose-dependent increase of the effects in all the assays. Analysis of MN in regenerated hepatocytes also indicated a significant positive correlation between time-course of chronic treatment and frequencies of micronucleated cells. But incidences of chromosome aberrations, MN and SCEs in bone marrow cells following repeated treatment for different periods did not differ greatly from each other; and these repeated treatment data, particularly in the MNT in bone marrow cells and the SCE assay, also did not differ markedly from the respective single treatment data for the same dose. This was probably due to the proliferative nature of the bone marrow cells.     

Near- and Far-Field Plasmonic Properties of Different Types of Eccentric Core-Shell Nanodimers

Finite element method (FEM) simulations have been carried out on free-standing and finite dielectric substrate-supported eccentric (i) silica core-gold nanoshell dimers and (ii) gold core-silica nanoshell dimers for understanding their near- and far-field plasmonic properties. In the case of eccentric silica core-gold nanoshell dimers, multiple peaks are observed in the near- and far-field spectra due to the plasmon hybridization. The number of peaks is found to be sensitive to the core offset parameters of the nanoshells forming nanodimer. The wavelength locations of the peaks due to the constructive coupling of the lower order modes found relatively more sensitive to the dielectric substrate. The number of peaks in the near- and far-field spectra found the same presence and absence of the dielectric substrate. The values of full width at half maximum (FWHM) of the peaks observed in the near-field spectra are found larger as compared to those observed in the far-field spectra. In contrast, in the case of eccentric gold core-silica nanoshell dimers, multiple peaks have not been observed. The FWHM of the observed peak is found sensitive to the core offset parameters of the nanoshells, and the number of peaks in the near field- and far-field spectra found not same in the presence and absence of the dielectric substrate. Moreover, the differences in near- and far-field spectra of plasmonically coupled (i) concentric nanoshells, (ii) eccentric nanoshells, and (iii) concentric and eccentric nanoshells also investigated numerically.

     

Contemporary Updates on the Physiology of Glucagon like Peptide-1 and Its Agonist to Treat Type 2 Diabetes Mellitus

Pathogenesis of diabetes mellitus involves scores of different factors, out of which Glucagon like factor-1 (GLP-1) plays a foremost role. GLP-1 is a pepti     

Microbiological strategies for enhancing biological nitrogen fixation in nonlegumes

In an agro-ecosystem, industrially produced nitrogenous fertilizers are the principal sources of nitrogen for plant growth; unfortunately these also serve as the leading sources of pollution. Hence, it becomes imperative to find pollution-free methods of providing nitrogen to crop plants. A diverse group of free-living, plant associative and symbiotic prokaryotes are able to perform biological nitrogen fixation (BNF). BNF is a two component process involving the nitrogen fixing diazotrophs and the host plant. Symbiotic nitrogen fixation is most efficient as it can fix nitrogen inside the nodule formed on the roots of the plant; delivering nitrogen directly to the host. However, most of the important crop plants are nonleguminous and are unable to form symbiotic associations. In this context, the plant associative and endophytic diazotrophs assume importance. BNF in nonlegumes can be encouraged either through the transfer of BNF traits from legumes or by elevating the nitrogen fixing capacity of the associative and endophytic diazotrophs. In this review we discuss mainly the microbiological strategies which may be used in nonleguminous crops for enhancement of BNF.     

Tunable luminescence of a synthesized furophenanthraquinone derivative: interactions with different solvents

The synthesis is described of a luminescent furophenanthraquinone derivative, 9‐methoxyphenanthro[4,3‐b]furan‐4,5‐dione (MPFD). The biological importance of tetracyclic furophenanthraquinones was considered and the tunable luminescence of MPFD in different solvents was studied to explore the nature of the specific interactions between MPFD and solvents. Observation of dual emission bands and identical nature of the fluorescence excitation spectra of MPFD monitored at the emission wavelength in polar solvents indicated the formation of two different types of species in the excited state, probably due to proton transfer from the solvent to MPFD. Luminescence intensity due to anionic species was found to be increased and the corresponding peak was red shifted with increase in the proton‐donating ability of the solvents, acting as an acid with respect to MPFD. Availability of more acidic protons in the solvent facilitated this phenomenon occurring in the excited state. MPFD also interacted with halogen‐containing solvents by forming electron donor–acceptor charge transfer (CT) complexes. This CT complex formation was dependent on the number of chlorine atoms; the position of the corresponding luminescence band varied with the polarity of the solvent. Extent of the CT increased with increase in the number of chlorine atoms in the dichloro, trichloro and tetrachloro solvents, whereas the luminescence peak due to the CT complex was found to be blue shifted with decrease in solvent polarity. Interaction of the synthesized bioactive MPFD with different solvents deserves biological importance as proton transfer and CT play pivotal roles in biology.