Identification of differentially expressed genes under heat stress conditions in rice (Oryza sativa L.)

Molecular Biology Reports - Rice production in recent years is highly affected by rapidly increasing temperatures in the tropical and sub-tropical countries, which threatens the sustainable...     

Effect of Metalaxyl on the incidence and severity of Pearl millet downy mildew disease in Northern Nigeria

Pearl millet downy mildew (DM) incidence, severity and yield losses of two pearl millet varieties (local and improved) due to the disease were determined in the field. Significant differences in the disease incidence and severity were recorded in the plots sown with metalaxyl-treated seeds and those sown with non-treated seeds, indicating the efficacy of the fungicide on the fungus. Yield losses due to non-treatment of seeds with metalaxyl was 40.88 and 45.39% in a local variety and 43.00 and 18.60% in an improved variety in the 2000 and 2001 cropping seasons respectively. Significant differences between plots sown with metalaxyl-treated and those sown with non-treated seeds were obtained for other yield components such as 1000-grains weight, panicle length and weight.     

Molecular Mechanics Studies of Dinucleoside Methylphosphonates: Influence of Methylphosphonate and its Chirality on the Phosphodiester Conformation

Abstract

Molecular mechanics studies are performed on single stranded as well as base paired forms of dinucleoside methylphosphonates comprising different base sequences for both the Sand R-isomers of methylphosphonate (MP). S-MP produces noticeable distortions in the geometry, locally at the phosphate center, and this enables the stereochemical feasibility of compact g^? g^? phosphodiester. Besides, it tends to perturb the conformations around the P- 03′ and glycosyl bonds, causing minor variations in stacking interactions. In single stranded dinucleosides, the gain in adjacent base stacking interaction energies seems to be sufficient to overcome the barrier to P-03′ bond rotation arising due to S-MP…sugar interaction, and this results in transition to a compact phosphodiester (B_I-type) from an initial extended phosphodiester (B_II-type) conformation. Such a thing seems rather difficult in base pair constrained duplexes. Dinucleosides with R-MP behave analogous to normal phosphate duplexes as the methyl group is away from the sugar. It is found that dinucleoside methylphosphonates are energetically less favoured than the corresponding dinucleoside phosphates mainly due to the depletion of contributions from electrostatic attractive interactions involving the base and sugar with the methylphosphonate consequent to the nonionic nature of the latter. Neither S-MP nor R-MP seem to significantly alter the stereochemistry of duplex structure.     

The cell aggregating propensity of probiotic actinobacterial isolates: isolation and characterization of the aggregation inducing peptide pheromone

The auto-aggregating ability of a probiotic is a prerequisite for colonization and protection of the gastrointestinal tract, whereas co-aggregation provides a close interaction with pathogenic bacteria. Peptide pheromone mediated signaling has been studied in several systems. However, it has not yet been explored in prokaryotes, especially actinobacteria. Hence, in the present study, the diffusible aggregation promoting factor was purified from the culture supernatant of a potent actinobacterial probiont and characterized using 20 different actinobacterial cultures isolated from the gut region of chicken and goat. The results showed that the pheromone-like compound induces the aggregation propensity of treated isolates. The factor was found to be a heat stable, acidic pH resistant, low molecular weight peptide which enhances the biofilm forming ability of other actinobacterial isolates. The aggregation promoting factor represents a bacterial sex factor (pheromone) and its characterization confirms its usage in the probiotic formulation     

Fluorescence detection of intracellular cadmium with Leadmium Green

Leadmium Green is a commercially available, small molecule, fluorescent probe advertised as a detector of free intracellular cadmium (Cd²⁺) and lead (Pb²⁺). Leadmium Green has been used in various paradigms, such as tracking Cd²⁺ sequestration in plant cells, heavy metal export in protozoa, and Pb²⁺ absorption by vascular endothelial cells. However very little information is available regarding its affinity and selectivity for Cd²⁺, Pb²⁺, and other metals. We evaluated the in vitro selectivity of Leadmium Green using spectrofluorimetry. Consistent with manufacturer’s claims, Leadmium Green was sensitive to Cd²⁺ (K_D ~600 nM) and also Pb²⁺ (K_D ~9.0 nM) in a concentration-dependent manner, and furthermore proved insensitive to Ca²⁺, Co²⁺, Mn²⁺ and Ni²⁺. Leadmium Green also responded to Zn²⁺ with a K_D of ~82 nM. Using fluorescence microscopy, we evaluated Leadmium Green in live mouse hippocampal HT22 cells. We demonstrated that Leadmium Green detected ionophore-mediated acute elevations of Cd²⁺ or Zn²⁺ in a concentration-dependent manner. However, the maximum fluorescence produced by ionophore-delivered Zn²⁺ was much less than that produced by Cd²⁺. When tested in a model of oxidant-induced liberation of endogenous Zn²⁺, Leadmium Green responded weakly. We conclude that Leadmium Green is an effective probe for monitoring intracellular Cd²⁺, particularly in models where Cd²⁺ accumulates rapidly, and when concomitant fluctuations of intracellular Zn²⁺ are minimal.     

Humpback whale singing activity off the Goan coast in the Eastern Arabian Sea

For over two decades, passive acoustic monitoring (PAM) methods have been successfully employed around the world for studying aquatic megafauna. PAM-driven studies in Indian waters have so far been relatively very scarce. Furthermore, cetacean populations inhabiting the north western Indian Ocean are far less studied than those in many other regions around the world. This work likely constitutes the first systematic study of the vocal repertoire of humpback whales (Megaptera novaeangliae) at a near-shore site along the western coast of India. Analysis of the observed vocalizations provides an insight into the behaviour of the species. This is significant as it assists in developing a better understanding of the habitat use of the non-migratory Arabian Sea humpback whale population. In contrast, other breeding populations such as those around the North Atlantic, South Pacific and Australia have been relatively well studied. Underwater passive acoustic data were collected during March 2017 using an autonomous logger at a shallow-water site off the eastern edge of Grande Island off the coast of Goa. Humpback whale vocalizations were found to occur over multiple days in the recordings. Time–frequency contours of individual units of vocalization were extracted with the aid of an automatic detection technique and the characteristics of the units were measured. Further, successive units were analysed for formation of phrases and themes. Reconstruction of putative songs from the identified units and themes was not possible due to the limitations imposed by the nature of data collection. Detailed analyses of units, phrases and themes are presented.     

Optical analysis of RE3+ (RE = Nd or Er):B2O3–P2O5–CaF2–ZnO–(Li2O/Na2O/K2O) glasses

Calcium boro fluoro zinc phosphate glasses modified using alkali oxide and doped with Nd³⁺ and Er³⁺ ions with the chemical composition of 69.5 (B₂O₃) + 10 (P₂O₅) + 10 (CaF₂) + 5 (ZnO) + 5 (Na₂O/Li₂O/K₂O) + 0.5 (Er₂O₃/Nd₂O₃) were prepared using a conventional melt quenching technique. The results of X-ray diffraction patterns indicated the amorphous nature of all the prepared glasses. The visible–near-infrared red (NIR) absorption spectra of these glasses were analyzed systematically. The NIR emission spectra of Er³⁺ and Nd³⁺:calcium boro fluoro zinc phosphate glasses showed prominent emission bands at 1536 nm (⁴I_13/2→⁴I_15/2) and 1069 nm (⁴F_3/2→⁴I_11/2) respectively with λ_exci = 514.5 nm (Ar⁺ laser) as the excitation source.     

Genetic engineering of indica rice with AtDREB1A gene for enhanced abiotic stress tolerance

Plant Cell, Tissue and Organ Culture (PCTOC) - Adventitious root (AR) culturing is an effective approach for obtaining bioactive compounds from the endangered plant species of Oplopanax elatus...