Phytoavailability and Leachability of Heavy Metals from Contaminated Soil Treated with Composted Livestock Manure

A study was carried out with maize as the test crop to investigate the bioavailability and leachability of heavy metals (HM) from HM-contaminated soils treated with composted manure. The application of composted manure increased the maize shoot growth by 32.3% and root growth by 30.5% compared with fresh manure. The concentration of HM in maize shoot varied in the order lead (Pb) > nickel (Ni) > zinc (Zn) > chromium (Cr) > copper (Cu) > cadmium (Cd). Whether for the shoot or root, the heavy metal concentrations decreased as the length of manure composting increased, but concentrations were higher in the root than the shoot. Composting decreased the bioavailability and leachability of HM and, hence, their export to the environment more effectively than direct use of fresh manure. Thus, the use of composted manure in place of fresh manure in polluted soils would be more beneficial for mitigating HM pollution.     

Therapeutic Potential of Selected Medicinal Plant Extracts against Multi-Drug Resistant Salmonella enterica serovar Typhi

Salmonella enterica serovar Typhi is Gram negative, rod shaped, facultative anaerobic bacterium, belongs to enterobacteriaceae family that causes typhoid fever in humans. This bacterium has become a super bug due to acquisition of multi drug resistance. Bacteria is transmitted through food and water contaminated with human feaces. Present study reports the screening of Adhatoda vasica, Amaranthus hybridus and Aloe barbadensis and their evaluation against multi-drug resistant Salmonella enterica serovar Typhi. Qualitative analysis of ten phytochemicals was conducted using chemical method and Gas Chromatography-Mass Spectrometry (GCMS). Antibacterial activity of plants was carried out by agar well diffusion method on Mueller Hinton agar. Total tannins, total alkaloids and total flavonoids of different parts of three plants were estimated through spectrophotometer. Total tannins content in different parts of plants was present in the given order Amaranthus hybridus leaf > Aloe barbadensis leaf > Adhatoda vasica leaf > Adhatoda vasica flower > Adhatoda vasica stem. Whereas, the order of total flavonoid concentration was Amaranthus hybridus leaf > Aloe barbadensis leaf > Adhatoda vasica leaf > Amaranthus hybridus seed. Total alkaloids have order, Adhatoda vasica leaf > Amaranthus hybridus leaf > Adhatoda vasica flower > Amaranthus hybridus seed > Aloe barbadensis leaf. Results of phytochemical analysis suggested that plants have strong profile of antioxidants, total phenolic contents and various enzymes proposing them best alternate to cure bacterial infections. GC-MS analysis further confirmed stronger phytochemical profile that can be utilized as antagonists to Salmonella enterica serovar Typhi.     

Photo-CIDNP solid-state NMR on Photosystems I and II:what makes P680 special?

The origin of the extraordinary high redox potential of P680, the primary electron donor of Photosystem II, is still unknown. Photochemically induced dynamic nuclear polarisation (photo-CIDNP) ¹³C magic-angle spinning (MAS) NMR is a powerful method to study primary electron donors. In order to reveal the electronic structure of P680, we compare new photo-CIDNP MAS NMR data of Photosystem II to those of Photosystem I. The comparison reveals that the electronic structure of the P680 radical cation is a Chl a cofactor with strong matrix interaction, while the radical cation of P700, the primary electon donor of Photosystem I, appears to be a Chl a cofactor which is essentially undisturbed. Possible forms of cofactor–matrix interactions are discussed.     

Transformation of Arabidopsis with the codA gene for choline oxidase enhances freezing tolerance of plants

Arabidopsis thaliana was transformed with the codA gene from Arthrobacter globiformis, which encodes choline oxidase, the enzyme that synthesizes glycinebetaine from choline. The transformation enabled the plants to accumulate glycinebetaine in chloroplasts, and significantly enhanced the freezing tolerance of plants. Furthermore, the photosynthetic machinery of transformed plants was more tolerant to freezing stress than that of wild-type plants. Exogenous application of glycinebetaine also increased the freezing tolerance of wild-type plants, suggesting that the presence of glycinebetaine in transformed plants had enhanced their ability to tolerate freezing stress. Northern blotting analysis revealed that the enhancement of freezing tolerance was not related to the expression of four cold-regulated genes. These results suggest that engineering of the biosynthesis of glycinebetaine by transformation with the codA gene might be an effective method for enhancing the freezing tolerance of plants.     

Plants and tortoises: mutations in the Arabidopsis jasmonate pathway increase feeding in a vertebrate herbivore

Photosynthetic tissues, the major food source of many invertebrates and vertebrates, are well defended. Many defence traits in leaves are controlled via the jasmonate signalling pathway in which jasmonate acts as a hormone by binding to a receptor to activate responses that lead to increased resistance to invertebrate folivores. We predicted that mutations in jasmonate synthesis might also increase the vulnerability of leaves to vertebrate folivores and tested this hypothesis using the Eastern Hermann’s tortoise (Eurotestudo boettgeri) and an Arabidopsis thaliana (Brassicaceae) allene oxide synthase (aos) mutant unable to synthesize jasmonate. Tortoises preferred the aos mutant over the wild type (WT). Based on these results, we then investigated the effect of mutating jasmonate perception using a segregating population of the recessive A. thaliana jasmonate receptor mutant coronatine insensitive1‐1 (coi1‐1). Genotyping of these plants after tortoise feeding revealed that the homozygous coi1‐1 receptor mutant was consumed more readily than the heterozygous mutant or the WT. Therefore, the plant’s ability to synthesize or perceive jasmonate reduces feeding by a vertebrate herbivore. We also tested whether or not tortoise feeding behaviour was influenced by glucosinolates, the principal defence chemicals in Arabidopsis leaves with known roles in defence against many generalist insects. However, in contrast to what has been observed with such insects, leaves in which the levels of these compounds were reduced genetically were consumed at a similar rate to those of the WT.     

Contribution of whole blood to the control of plasma asymmetrical dimethylarginine

The endogenous nitric oxide (NO) synthase (NOS) inhibitor asymmetrical dimethylarginine (ADMA) is elevated in many patients and may contribute to the initiation and progression of their disease. While some mechanistic pathways have been identified, tissue-specific contributions to ADMA control remain unclear. We sought to determine if whole blood (WB) could participate in ADMA control ex vivo. Anesthetized male Sprague-Dawley rats underwent exsanguinations, and WB preparations were incubated at 37 degrees C for 5 h. ADMA and symmetrical dimethylarginine were analyzed by high-pressure liquid chromatography. Incubation of lysed red blood cell (RBC) supernatant yielded a significant decrease in ADMA that was blocked by 4124W, a synthetic inhibitor of dimethylarginine dimethylaminohydrolase, the only reported enzyme to hydrolyze ADMA. Hydrolysis of ADMA was diminished by addition of physiologically relevant concentrations of zinc (i.e., 20 microM). Conversely, when rat WB or WB supernatant was incubated at 37 degrees C, it liberated quantities of free ADMA (1-2 microM) that in vivo would likely have pathological consequences. Addition of arginine methyltransferase inhibitors to these incubations did not reduce ADMA release, indicating no dominant role for active protein methylation during these incubations. This ADMA liberation was significantly reduced by addition of protease inhibitors, indicating a dependence on peptide bond hydrolysis. Total ADMA (protein incorporated plus free) was determined by acid hydrolysis and found to be 43.18 +/- 4.79 microM in WB with approximately 95% of this in RBCs. These ex vivo data demonstrate the potential of blood to control the NO-NOS system by modulating free ADMA.