CO2 and water vapour exchange in four alpine herbs at two altitudes and under varying light and temperature conditions

CO₂ and water vapour exchange rates of four alpine herbs namely: Rheum emodi, R. moorcroftianum, Megacarpaea polyandra and Rumex nepalensis were studied under field conditions at 3600 m (natural habitat) and 550 m altitudes. The effect of light and temperature on CO₂ and water vapour exchange was studied in the plants grown at lower altitude. In R. moorcroftianum and R. nepalensis, the average photosynthesis rates were found to be about three times higher at 550 m as compared to that under their natural habitat. However, in M. polyandra, the CO₂ exchange rates were two times higher at 3600 m than at 550 m but in R. emodi, there were virtually no differences at the two altitudes. These results indicate the variations in the CO₂ exchange rates are species specific. The change in growth altitude does not affect this process uniformly.The transpiration rates in R. emodi and M. polyandra were found to be very high at 3600 m compared to 550 m and are attributed to overall higher stomatal conductance in plants of these species, grown at higher altitude. The mid-day closure of stomata and therefore, restriction of transpirational losses of water were observed in all the species at 550 m altitude. In addition to the effect of temperature and relative humidity, the data also indicate some endogenous rhythmic control of stomatal conductance.The temperature optima for photosynthesis was close to 30°C in M. polyandra and around 20°C in the rest of the three species. High temperature and high light intensity, as well as low temperature and high light intensity, adversely affect the net rate of photosynthesis in these species.Both light compensation point and dark respiration rate increased with increasing temperature.The effect of light was more prominent on photosynthesis than the effect of temperature, however, on transpiration the effect of temperature was more prominent than the effect of light intensity.No definite trends were found in stomatal conductance with respect to light and temperature. Generally, the stomatal conductance was highest at 20°C.The study reveals that all these species can easily be cultivated at relatively lower altitudes. However, proper agronomical methodology will need to be developed for better yields.     

Isolation and characterization of plant growth-promoting strain Pantoea NII-186. From Western Ghat Forest soil, India

Aims:  To isolate plant growth-promoting bacterium from Western Ghat forests in India.
Methods and Results:  A Gram-negative, rod shaped, cream white coloured strain Pantoea NII-186 isolated from Western Ghat soil sample. The taxonomic position of the bacterium was confirmed by sequencing of 16S rRNA and phylogenetic analysis. A strain grew at a wide range of temperature ranging from 5–40°C, but optimum growth was observed at 28–30°C. It showed multiple plant growth-promoting attributes such as phosphate solubilization activity, indole acetic acid (IAA) production, siderophore production and HCN production. It was able to solubilize (28 μg of Ca₃PO₄ ml⁻¹ day⁻¹), and produce IAA (59 μg) at 28°C. The solubilization of insoluble phosphate was associates with a drop in the pH of the culture medium. Pantoea sp. NII-186 tolerate to different environmental stresses like 5–40°C, 0–7% salt concentration and 4–12 pH range.
Conclusions:  The 16S rRNA gene sequence confirmed that the isolate NII-186 was belongs to Pantoea genus and showed considerable differences in physiological properties with previously reported species of this genus. Isolate NII-186 possessed multiple attributes of plant growth-promoting activity.
Significance and Impact of the Study:  Hence in the context it is proposed that Pantoea sp. NII-186, could be deployed as an inoculant to attain the desired plant growth-promoting activity in agricultural environment.     

Quantitative determination of formononetin and its metabolite in rat plasma after intravenous bolus administration by HPLC coupled with tandem mass spectrometry

A new simple, rapid, sensitive and accurate quantitative detection method using liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) for the measurement of formononetin (FMN) and daidzein (DZN) levels in rat plasma is described. Analytes were separated on a Supelco Discovery C18 (4.6 × 50 mm, 5.0 μm) column with acetonitrile: methanol (50:50, v/v) and 0.1% acetic acid in the ratio of 90:10 (v/v) as a mobile phase. The method was proved to be accurate and precise at linearity range of 5–100 ng/mL with a correlation coefficient (r) of ≥0.996. The intra- and inter-day assay precision ranged from 1.66–6.82% and 1.87–6.75%, respectively; and intra- and inter-day assay accuracy was between 89.98–107.56% and 90.54–105.63%, respectively for both the analytes. The lowest quantitation limit for FMN and DZN was 5.0 ng/mL in 0.1 mL of rat plasma. Practical utility of this new LC–MS/MS method was demonstrated in a pharmacokinetic study in rats following intravenous administration of FMN.     

Variation of Trace Elements Contents in Asparagus racemosus (Willd)

The present study was carried out to determine the accumulation and variation of trace elements in roots and leaves of Asparagus racemosus collected from four different altitudes in Uttarakhand, India, by atomic absorption spectroscopy. The metals investigated were Zn, Cu, Mn, Fe, Co, Na, K, Ca, and Li. The concentration level of Fe was found to be highest at an altitude of 2,250 m, whereas the level of Cu was lowest. The maximum concentrations of Zn, Cu, Mn, Fe, Co, Na, K, Ca, and Li were found to be 165.0?±?3.2, 34.0?±?0.5, 84.0?±?0.7, 2,040.0?±?0.3, 122.0?±?1.5, 745.0?±?0.3, 13,260.0?±?3.5, 6,153.0?±?1.6, and 58.0?±?3.8 mg/kg, respectively.     

Study on the Variations of Mineral Elements in Swertia speciosa (G. Don)

Variations of micro- and macrominerals concentration in Swertia speciosa were determined by atomic absorption spectroscopy. The mineral elements showed significant changes in roots and leaves collected from different altitudes. Among all the elements, highest concentration (more than 2,000 mg/kg) of Ca and K were recorded in S. speciosa and the concentration of other elements analyzed in the study decreased in the order Fe>Na>Zn>Co>Li>Cu>Mn.     

Interaction studies of novel cell selective antimicrobial peptides with model membranes and E. coli ATCC 11775

Cationic antimicrobial peptides (CAMPs) are novel candidates for drug development. Here we describe design of six short and potent CAMPs (SA-1 to SA-6) based on a minimalist template of 12 residues H+HHG+HH+HH+NH2 (where H: hydrophobic amino acid and +: charged hydrophilic amino acid). Designed peptides exhibit good antibacterial activity in micro molar concentration range (1-32 μg/ml) and rapid clearance of Gram-positive and Gram-negative bacterial strains at concentrations higher than MIC. For elucidating mode of action of designed peptides various biophysical studies including CD and Trp fluorescence were performed using model membranes. Further based on activity, selectivity and membrane bound structure; modes of action of Trp rich peptide SA-3 and template based peptide SA-4 were compared. Calcein dye leakage and transmission electron microscopic studies with model membranes exhibited selective membrane active mode of action for peptide SA-3 and SA-4. Extending our work from model membranes to intact E. coli ATCC 11775 in scanning electron micrographs we could visualize different patterns of surface perturbation caused by peptide SA-3 and SA-4. Further at low concentration rapid translocation of FITC-tagged peptide SA-3 into the cytoplasm of E. coli cells without concomitant membrane perturbation indicates involvement of intracellular targeting mechanism as an alternate mode of action as was also evidenced in DNA retardation assay. For peptide SA-4 concentration dependent translocation into the bacterial cytoplasm along with membrane perturbation was observed. Establishment of a non specific membrane lytic mode of action of these peptides makes them suitable candidates for drug development.     

Disruption of Elements Uptake due to Excess Chromium in Indian Medicinal Plants

Chromium and its compounds may cause disturbance in the nutrient level of the plants. Iron, manganese, copper, and zinc are essential nutrient elements and required for balanced growth and development of plants, but chromium uptake sometimes disturbed their concentration in plants. Therefore, in the present paper, an effort has been made to observe the effect of different levels of Cr on nutrient uptake of Phyllanthus amarus and Solanum nigrum, the medicinally important plants of indigenous systems of medicine having hepatoprotective and diuretic properties. The study revealed that Cr causes significant changes in nutrient uptake as compared to control plants. Besides, Cr-treated plants showed growth depression and decrease in fresh and dry weight too. With the increase in Cr supply, accumulation of Cr in roots was increased significantly. Concentration of manganese and zinc was also increased. However, copper concentration in both the plants seemed less affected by Cr.