Chemical regulators of carotenogenesis by Blakeslea trispora

The activation of the carotene biosynthetic pathway in Blakeslea trispora was found to occur by trisporic acid and many other compounds such as abscisic acid, β-ionone, α-ionone and vitamin A which share significant structural similarity with trisporic acid. The magnitude of stimulatory activities of these effectors was in the order trisporic acid > abscisic acid > β-ionone > α-ionone > vitamin A. Comparison of structures and stimulatory activities of all the effectors indicated that the short length of the side chain and the presence of a keto group in the ring structure of the trisporic acid molecule contributed significantly to the biological activity towards carotenogenesis.     

Interaction between Rhizobium japonicum phage M-1 and its receptor

The receptor for phage M-1 was present in the exopolysaccharide (EPS) of Rhizobium japonicum D211. The EPS was a heteropolysaccharide consisting of glucose, galactose, glucuronic acid, and glucosamine units. These monosaccharides prevented phage-cell attachment indicating that they may mimick the receptor. Phage-cell attachment was either stimulated or inhibited by Mg2+ and Ca2+ depending upon their concentration. An enzyme which depolymerized the exopolysaccharide releasing oligosaccharides was detected in the phage-infected cell lysates. A comparison of the properties of adsorption and those of the depolymerase enzyme indicated that the latter was a component of the phage and appeared to be involved in the phage-receptor interaction.     

Fructose-1,6-diphosphatase from Mangifera indica

Fructose-1,6-diphosphatase (FDPase) from unripe mango was separated into two components by ammonium sulfate fractionation, one active at pH 6 (acidic FDPase) and the other at pH 8.5 (alkaline FDPase). The alkaline component had a lower K_m. (0.15 × 10^?3 M) than the acidic component (1.7 × 10^?3 M) towards the substrate (FDP) and the allosteric inhibitor AMP. It also showed greater heat stability and higher activation in the presence of EDTA as compared to the acidic FDPase. Both components showed a higher activation with Mn²⁺ ions than with Mg²⁺ ions.     

Spectrophotometric measurements on verdo-myoglobin: relevance to the oxidation of ferri-myoglobin by chlorite ion

Spectrophotometric observations on verdo-myoglobin, reconstituted from apomyoglobin and verdo-heme and its oxidation products, are described. Relevance of these results to the oxidation of ferri-myoglobin by chlorite ion is also discussed.     

Clinical and Treatment Aspects of Brown–Black Fungi

Brown–black (or dematiaceous) fungi are responsible for a wide variety of infectious syndromes in both immunocompetent and immunocompromised patients, including local infections, allergic disease, pneumonia, brain abscess, and disseminated infection. They are distinct from the more common hyaline molds, Aspergillus and Fusarium, that cause human disease. They are often found in soil and generally distributed worldwide. In recent years, these fungi have been increasingly recognized as important pathogens. Dematiaceous fungi may have unique pathogenic mechanisms owing to the presence of melanin in their cell walls, which imparts the characteristic dark color to their spores and hyphae. Diagnosis rests on careful microscopic and pathologic examination, as there are no specific laboratory tests to reliably identify these fungi. Therapy depends upon the clinical syndrome, although disseminated infection often has high mortality. Triazoles such as voriconazole, posaconazole, and itraconazole are the most active antifungal agents available. Further studies are needed to better understand the pathogenesis and optimal treatment of these uncommon infections.     

MsrA Efflux Pump Inhibitory Activity of Piper cubeba L.f. and its Phytoconstituents against Staphylococcus aureus RN4220

MsrA, an efflux pump belonging to ATP‐binding cassette (ABC) transporter family that conferred resistance to macrolides, was detected in Staphylococcus aureus strains. Herein, we report the isolation of phytoconstituents from Piper cubeba fruit methanol extract and investigated their efflux pump inhibitory potential against S. aureus MsrA pump. Four isolated compounds, viz. pellitorine, sesamin, piperic acid and tetrahydropiperine studied in combination with erythromycin in S. aureus RN4220, exhibited 2–8‐fold reduction in minimum inhibitory concentration (MIC) of erythromycin. Pellitorine and sesamin decreased MIC of erythromycin by 8‐fold. The real‐time fluorometry‐based efflux and accumulation studies of ethidium bromide (EtBr) on S. aureus RN4220 in the presence of these compounds showed reduced efflux and enhanced uptake, thus indicating inhibition of the efflux pump. Pellitorine showed significant post‐antibiotic effect of erythromycin. The results revealed that the primary mechanism of action of these compounds involves steady ATP production impairment.     

Neuronal control of lipid metabolism by STR‐2 G protein‐coupled receptor promotes longevity in Caenorhabditis elegans

The G protein‐coupled receptor (GPCR) encoding family of genes constitutes more than 6% of genes in Caenorhabditis elegans genome. GPCRs control behavior, innate immunity, chemotaxis, and food search behavior. Here, we show that C. elegans longevity is regulated by a chemosensory GPCR STR‐2, expressed in AWC and ASI amphid sensory neurons. STR‐2 function is required at temperatures of 20°C and higher on standard Escherichia coli OP50 diet. Under these conditions, this neuronal receptor also controls health span parameters and lipid droplet (LD) homeostasis in the intestine. We show that STR‐2 regulates expression of delta‐9 desaturases, fat‐5, fat‐6 and fat‐7, and of diacylglycerol acyltransferase dgat‐2. Rescue of the STR‐2 function in either AWC and ASI, or ASI sensory neurons alone, restores expression of fat‐5, dgat‐2 and restores LD stores and longevity. Rescue of stored fat levels of GPCR mutant animals to wild‐type levels, with low concentration of glucose, rescues its lifespan phenotype. In all, we show that neuronal STR‐2 GPCR facilitates control of neutral lipid levels and longevity in C. elegans.     

Multigene CRISPR/Cas9 genome editing of hybrid proline rich proteins (HyPRPs) for sustainable multi-stress tolerance in crops: the review of a promising approach

Physiology and Molecular Biology of Plants - The recent global climate change has directly impacted major biotic and abiotic stress factors affecting crop productivity worldwide. Therefore, the...     

Poly ethylene glycol mediated in vitro screening and physico-biochemical changes induced in mango callus due to moisture stress

Plant Cell, Tissue and Organ Culture (PCTOC) - A method for in vitro screening and selection of drought (moisture stress) tolerant mango calli was developed. Poly ethylene glycol (PEG) (Molecular...