A report on extensive lateral genetic reciprocation between arsenic resistant Bacillus subtilis and Bacillus pumilus strains analyzed using RAPD-PCR.

The study involves isolation of arsenic resistant bacteria from soil samples. The characterization of bacteria isolates was based on 16S rRNA gene sequences. The phylogenetic consanguinity among isolates was studied employing rpoB and gltX gene sequence. RAPD-PCR technique was used to analyze genetic similarity between arsenic resistant isolates. In accordance with the results Bacillus subtilis and Bacillus pumilus strains may exhibit extensive horizontal gene transfer. Arsenic resistant potency in Bacillus sonorensis and high arsenite tolerance in Bacillus pumilus strains was identified. The RAPD-PCR primer OPO-02 amplified a 0.5kb DNA band specific to B. pumilus 3ZZZ strain and 0.75kb DNA band specific to B. subtilis 3PP. These unique DNA bands may have potential use as SCAR (Sequenced Characterized Amplified Region) molecular markers for identification of arsenic resistant B. pumilus and B. subtilis strains.

Efficient method for Agrobacterium mediated transformation of Artemisia annua L.

Artemisinin, a potent antimalarial natural products isolated from aerial parts of Artemisia annua L. Many patents have been reported that the demand for artemisinin is exponentially increasing year after year due to increased incidences of drug resistant malaria throughout the world. Leaf explants were used frequently as target tissue to generate transgenic of Artemisia. annua L. However, obtaining a large number of transgenic lines through out the year is a laborious and delicate process. To circumvent this, we have developed a highly efficient leaf explant based Agrobacterium mediated transformation of A. annua L. plant. The gus gene was used as screenable marker to assess and optimize the performance of T-DNA delivery. The age of explant, kind of bacterial inoculation, suspension duration, infection times and co-culture conditions were optimized. The co-culture was carried out with Agrobacterium tumefaciens strain EHA105 under desiccation condition in the dark at 25-28 0C for 2-4 days. Complete analysis of transgene insertion demonstrated that the optimized method of transformation from leaf explants of A. annua L. was efficient and highly reproducible.

Variation in oil content and fatty acid composition of the seed oil of Acacia species collected from the northwest zone of India.

BACKGROUND: The oil content and fatty acid composition of the mature seeds of Acacia species collected from natural habitat of the northwest zone of the Indian subcontinent (Rajasthan) were analyzed in order to determine their potential for human or animal consumption. RESULTS: Oil content varied between 40 and 102 g kg⁻¹. The highest oil content was obtained in Acacia bivenosa DC. (102 g kg⁻¹) among the nine Acacia species. The fatty acid composition showed higher levels of unsaturated fatty acids, especially linoleic acid (~757.7 g kg⁻¹ in A. bivenosa), oleic acid (~525.0 g kg⁻¹ in A. nubica) and dominant saturated fatty acids were found to be 192.5 g kg⁻¹ palmitic acid and 275.6 g kg⁻¹ stearic acid in A. leucophloea and A. nubica respectively. Seed oils of Acacia species can thus be classified in the linoleic-oleic acid group. Significant variations were observed in oil content and fatty acid composition of Acacia species. CONCLUSION: The present study revealed that the seed oil of Acacia species could be a new source of high linoleic-oleic acid-rich edible oil and its full potential should be exploited. The use of oil from Acacia seed is of potential economic benefit to the poor native population of the areas where it is cultivated. The fatty acid composition of Acacia seed oils is very similar to that reported for commercially available edible vegetable oils like soybean, mustard, sunflower, groundnut and olive. Hence the seed oil of Acacia species could be a new source of edible vegetable oil after toxicological studies.

Screening and detection of biomarkers in chickpea plants exposed to chromium and cadmium.

A broad screening protocol, covering the most general phytochemical groups of compounds, was developed on the basis of high performance thin layer chromatography (HPTLC). A total of six TLC systems, comprising three derivatization reagents, two stationary phases and two mobile phases, were included. The screening method was applied for the identification of biomarkers in the chickpea plant exposed to cadmium and chromium. The biomarkers were selected on the basis of significant changes (0.26-4.6 fold) in concentration levels of phytochemicals. Totally, five different amino acids, three organic acids, one sulphur containing compound and one sugar were identified as biomarkers in chickpea exposed heavy metal.

Isolation, characterization and structural studies of amorpha - 4, 11-diene synthase (ADS(3963)) from Artemisia annua L.

With the escalating prevalence of malaria in recent years, artemisinin demand has placed considerable stress on its production worldwide. At present, the relative low-yield of artemisinin (0.01-1.1 %) in the source plant (Artemisia annua L. plant) has imposed a serious limitation in commercializing the drug. Amorpha-4, 11-diene synthase (ADS) has been reported a key enzyme in enhancing the artemisinin level in Artemisia annua L. An understanding of the structural and functional correlations of Amorpha-4, 11-diene synthase (ADS) may therefore, help in the molecular up-regulation of the enzyme. In this context, an in silico approach was used to study the ADS3963 (3963 bp) gene cloned by us, from high artemisinin (0.7-0.9% dry wt basis) yielding strain of A. annua L. The full-length putative gene of ADS3963 was found to encode a protein consisting of 533 amino acid residues with conserved aspartate rich domain. The isoelectric point (pI) and molecular weight of the protein were 5.25 and 62.2 kDa, respectively. The phylogenetic analysis of ADS genes from various species revealed evolutionary conservation. Homology modeling method was used for prediction of the 3D structure of ADS3963 protein and Autodock 4.0 version was used to study the ligand binding. The predicted 3D model and docking studies may further be used in characterizing the protein in wet laboratory.

Structural and functional characterization of HMG-COA reductase from Artemisia annua.

Plants synthesize a great variety of isoprenoid products that are required not only for normal growth and development but also for their adaptive responses to environmental challenges. However, despite the remarkable diversity in the structure and function of plant isoprenoids, they all originate from a single metabolic precursor, mevalonic acid. The synthesis of mevalonic acid is catalysed by the enzyme, 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG- CoA reductase). The analysis of the amino acid sequence of HMG-CoA reductase from Artemisia annua L. plant showed that it belongs to class I HMG-CoA reductase family. The three dimensional structure of HMG-CoA reductase of Artemisia annua has been generated from amino acid sequence using homology modelling with backbone structure of human HMG-CoA reductase as template. The model was generated using the SWISS MODEL SERVER. The generated 3-D structure of HMG-CoA reductase was evaluated at various web interfaced servers to checks the stereo interfaced quality of the structure in terms of bonds, bond angles, dihedral angles and non-bonded atom-atom distances, structural as well as functional domains etc. The generated model was visualized using the RASMOL. Structural analysis of HMG-CoA reductase from Artemisia annua L. plant hypothesize that the N and C-terminals are positioned in cytosol by the two membrane spanning helices and the C-terminals domain shows similarity to the human HMG-CoA reductase enzyme indicating that they both had potential catalytic similarities.