Stimulatory Effect of Partial Desiccation on Plant Regeneration in Indica Rice (Oryza sativa L)

A simple in vitro protocol was established for high frequency plant regeneration via organogenesis and somatic embryogenesis from the callus cultures derived from immature inflorescence segments of indica rice (Oryza sativa L cvs Safari-17 and Kasturi). Embryogenic and nodular calli were initiated on MSB medium supplemented with 2, 4-D and sucrose (3.0%, w/v). Somatic embryogenesis occurred after transfer of embryogenic calli to MSB medium containing 2.25 μM 2,4-D, 2.2 μM BAP, 2.9 μM thiamine HCl and 244.86 μM L-tryptophan. Plantlet/shoot regeneration occurred after transfer of embryogenic calli to MSB medium containing 17.6 μM BAP and 1.12 μM 2,4-D. Partial desiccation (up to 12, 24, 48, 72 and 96 h) of embryogenic calli prior to transfer to regeneration medium stimulated regeneration frequency. Highly significant (P<0.001) difference was observed for regeneration frequency and average number of plantlets/shoots regenerated per callus in partially desiccated calli in comparison to non-dehydrated calli. Regeneration frequency increased from 33.3% to 80% after 24 h of desiccation treatment to callus cultures of cv. Safari-17, and from 46.7% to 93.3% after 48 h of desiccation treatment to callus tissues of cv. Kasturi. Regenerated shoots were rooted on MSB medium supplemented with 4.9 μM IBA. Plants with well-developed roots were transferred to pots where they grew well and attained maturity.     

Bio-prospectus of cadmium bioadsorption by lactic acid bacteria to mitigate health and environmental impacts

Applied Microbiology and Biotechnology - Foodstuffs and water are the key sources of cadmium biomagnifiaction. The available strategies to mitigate this problem are unproductive and expensive for...     

Chemical Composition,Cytotoxic and Antibacterial Activities of Essential Oils of Cultivated Clones of Juniperus communis and Wild Juniperus Species

Needles of seven cultivated clones (C1 – C7) of Juniperus communis at lower altitude and three wild Juniperus species (J. communis, J. recurva and J. indica) at higher altitudes were investigated comparatively for their essential oils (EOs) yields, chemical composition, cytotoxic and antibacterial activities. The EOs yields varied from 0.26 to 0.56% (v/w) among samples. Sixty‐one volatile components were identified by gas chromatography‐mass spectrometry (GC/MS) and quantified using gas chromatography GC (FID) representing 82.5 – 95.7% of the total oil. Monoterpene hydrocarbons (49.1 – 82.8%) dominated in all samples (α‐pinene, limonene and sabinene as major components). Principal component analysis (PCA) of GC data revealed that wild and cultivated Juniperus species are highly distinct due to variation in chemical composition. J. communis (wild species) displayed cytotoxicity against SiHa (human cervical cancer), A549 (human lung carcinoma) and A431 (human skin carcinoma) cells (66.4 ± 2.2%, 74.4 ± 1.4% and 57.4 ± 4.0%), respectively, at 200 μg/ml. EOs exhibited better antibacterial activity against Gram‐positive bacteria than against Gram‐negative bacteria with the highest zone of inhibition against Staphylococcus aureus MTCC 96 (19.2 ± 0.7) by clone‐7. As per the conclusion of the findings, EOs of clone‐2, clone‐5 and clone‐7 can be suggested to the growers of lower altitude, as there is more possibility of uses of these EOs in food and medicinal preparations.     

Scavenging of hydroxyl,methoxy, and nitrogen dioxide free radicals by some methylated isoflavones

Free radicals can be scavenged from biological systems by genistein, daidzein, and their methyl derivatives through hydrogen atom transfer (HAT), single-electron transfer (SET), and sequential proton-loss electron-transfer (SPLET) mechanisms. Reactions between these derivatives and the free radicals OH^., OCH₃^., and NO₂^. via the HAT mechanism in the gas phase were studied using the transition state theory within the framework of DFT. Solvation of all the species and complexes involved in the HAT reactions in aqueous media was treated by performing single point energy calculations using the polarizable continuum model (PCM). The SET and SPLET mechanisms for the above reactions were also considered by applying the Marcus theory of electron transfer, and were found to be quite sensitive to geometry and solvation. Therefore, the geometries of all the species involved in the SET and SPLET mechanisms were fully optimized in aqueous media. The calculated barrier energies and rate constants of the HAT-based scavenging reactions showed that the OH group of the B ring in genistein, daidzein, and their methyl derivatives plays a major role in the scavenging of free radicals, and the role of this OH group in the HAT-based free-radical scavenging decreases in the following order: OH^.?>?OCH₃^. > NO₂^.. The SPLET mechanism was found to be an important mechanism in these free-radical scavenging reactions, whereas the SET mechanism was not important in this context.     

Bench scale production of butyramide using free and immobilized cells of Bacillus sp. APB-6

Bioprocess and Biosystems Engineering - Butyramide is a commodity chemical having wide range of applications from material science to biological sciences including synthesis of therapeutic drugs,...     

Imidacloprid impedes mitochondrial function and induces oxidative stress in cotton bollworm, <Emphasis Type="Italic">Helicoverpa armigera</Emphasis> larvae (Hubner: Noctuidae)

Neonicotinoids have high agonistic affinity to insect nicotinic acetylcholine receptors (nAChR) and are frequently used as insecticides against most devastating lepidopteran insect pests. Imidacloprid influenced dose-dependent decline in the state III and IV respiration, respiration control index (RCI), and P/O ratios, in vitro and in vivo. The bioassay indicated its LD₅₀ value to be 531.24 μM. The insecticide exhibited a dose-dependent inhibition on F₀F₁-ATPase and complex IV activity. At 600 μM, the insecticide inhibited 83.62 and 27.13% of F₀F₁-ATPase and complex IV activity, respectively, and induced the release of 0.26 nmoles/min/mg protein of cytochrome c. A significant dose- and time-dependent increase in oxidative stress was observed; at 600 μM, the insecticide correspondingly induced lipid peroxidation, LDH activity, and accumulation of H₂O₂ content by 83.33, 31.51 and 223.66%. The stress was the maximum at 48 h of insecticide treatment (91.58, 35.28, and 189.80%, respectively). In contrast, catalase and superoxide dismutase were reduced in a dose- and time-dependent manner in imidacloprid-fed larvae. The results therefore suggest that imidacloprid impedes mitochondrial function and induces oxidative stress in H. armigera, which contributes to reduced growth of the larvae along with its neurotoxic effect.     

Disruption to the 5-HT<Subscript>7</Subscript> Receptor Following Hypoxia–Ischemia in the Immature Rodent Brain

It has become increasingly evident the serotonergic (5-hydroxytryptamine, 5-HT) system is an important central neuronal network disrupted following neonatal hypoxic–ischemic (HI) insults. Serotonin acts via a variety of receptor subtypes that are differentially associated with behavioural and cognitive mechanisms. The 5-HT₇ receptor is purported to play a key role in epilepsy, anxiety, learning and memory and neuropsychiatric disorders. Furthermore, the 5-HT₇ receptor is highly localized in brain regions damaged following neonatal HI insults. Utilising our well-established neonatal HI model in the postnatal day 3 (P3) rat pup we demonstrated a significant decrease in levels of the 5-HT₇ protein in the frontal cortex, thalamus and brainstem one week after insult. We also observed a relative decrease in both the cytosolic and membrane fractions of 5-HT₇. The 5-HT₇ receptor was detected on neurons throughout the cortex and thalamus, and 5-HT cell bodies in the brainstem. However we found no evidence of 5-HT₇ co-localisation on microglia or astrocytes. Moreover, minocycline treatment did not significantly prevent the HI-induced reductions in 5-HT₇. In conclusion, neonatal HI injury caused significant disruption to 5-HT₇ receptors in the forebrain and brainstem. Yet the use of minocycline to inhibit activated microglia, did not prevent the HI-induced changes in 5-HT₇ expression.     

Synthesis of (±)-7,3′- and 7,4′-di-O-methyleriodictyol and of velutin and pilloin

Synthetic 2′-hydroxy-3,4′,6′-trimethoxy-4-benzyloxychalcone (I) affords (±)-7,3′-di-O-methyleriodictyol (II) and 7,3′-di-O-methylluteolin (or velutin, VII) identical with natural samples. Similarly synthetic 2′-hydroxy-4,4′,6′-trimethoxy-3-benzyloxychalcone (X) gives natural (±)-7,4′-di-O-methyleriodictyol (XI) and 7,4′-di-O-methylluteolin (or pilloin, IX). However, attempts to partially etherify II with one mole of prenyl bromide to obtain the natural prenyl ether failed; only the corresponding diprenyloxychalcone (IV) was obtained.