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Suku S.,Malankara Catholic College | Knipfer T.,University College Dublin | Fricke W.,University College Dublin
Annals of Botany | Year: 2014

Background and AimsAs annual crops develop, transpirational water loss increases substantially. This increase has to be matched by an increase in water uptake through the root system. The aim of this study was to assess the contributions of changes in intrinsic root hydraulic conductivity (Lp, water uptake per unit root surface area, driving force and time), driving force and root surface area to developmental increases in root water uptake. MethodsHydroponically grown barley plants were analysed during four windows of their vegetative stage of development, when they were 9-13, 14-18, 19-23 and 24-28 d old. Hydraulic conductivity was determined for individual roots (Lp) and for entire root systems (Lpr). Osmotic Lp of individual seminal and adventitious roots and osmotic Lpr of the root system were determined in exudation experiments. Hydrostatic Lp of individual roots was determined by root pressure probe analyses, and hydrostatic Lpr of the root system was derived from analyses of transpiring plants.Key ResultsAlthough osmotic and hydrostatic Lp and Lpr values increased initially during development and were correlated positively with plant transpiration rate, their overall developmental increases (about 2-fold) were small compared with increases in transpirational water loss and root surface area (about 10- to 40-fold). The water potential gradient driving water uptake in transpiring plants more than doubled during development, and potentially contributed to the increases in plant water flow. Osmotic Lpr of entire root systems and hydrostatic Lpr of transpiring plants were similar, suggesting that the main radial transport path in roots was the cell-to-cell path at all developmental stages.ConclusionsIncrease in the surface area of root system, and not changes in intrinsic root hydraulic properties, is the main means through which barley plants grown hydroponically sustain an increase in transpirational water loss during their vegetative development. © 2013 © The Author 2013. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup. com.

Prakash Williams G.,Malankara Catholic College | Gnanadesigan M.,Alagappa University | Ravikumar S.,Alagappa University
Bioresource Technology | Year: 2012

The present study is an attempt to find out the promising metal (Ni 2+, Al 3+, and Hg 2+) biosorbant halobacterial strains from saltern pan and to study their biokinetic parameters for metal recovery. Of the selected 65 isolates, Natronobacterium magadii, Natronococcus occultus and Halobacterium sodomense shows the maximum metal resistance activity against Ni 2+ (250ppm), Al 3+ (600ppm) and Hg 2+ (25ppm) metals. Biokinetic parameters such as maximum specific growth rate (μ max), substrate removable [S] rate, half velocity constant (K s), endogenous or decay co-efficient (k d), yield co-efficient rate (Yd -1) are also analyzed for the selected metals. Further the results of the SEM-EDS analysis confirms the metals uptake of Ni 2+ and Al 3+ in higher concentration and Hg 2+ in lower concentration. It is concluded from the present study that, the biosorption of heavy metals by solar saltern halobacteria can be used as a potential source for the bioremediation of metals. © 2011 Elsevier Ltd.

Valan A.M.,Entomology Research Institute | Asha K.R.T.,Malankara Catholic College | Duraipandiyan V.,King Saud University | Ignacimuthu S.,Entomology Research Institute | And 2 more authors.
Asian Pacific Journal of Tropical Biomedicine | Year: 2012

Objective: To isolate and indentify the promising antimicrobial metabolite producing . Streptomyces strains from marine sediment samples from Andrapradesh coast of India. Methods: Antagonistic actinomycetes were isolated by starch casein agar medium and modified nutrient agar medium with 1% glucose used as a base for primary screening. Significant antimicrobial metabolite producing strains were selected and identified by using biochemical and 16S rDNA level. Minimum inhibitory concentrations of the organic extracts were done by using broth micro dilution method. Results: Among the 210 actinomycetes, 64.3% exhibited activity against Gram positive bacteria, 48.5 % showed activity towards Gram negative bacteria, 38.8% exhibited both Gram positive and negative bacteria and 80.85 % isolates revealed significant antifungal activity. However, five isolates AP-5, AP-18, AP-41 and AP-70 showed significant antimicrobial activity. The analysis of cell wall hydrolysates showed the presence of LL-diaminopimelic acid and glycine in all the isolates. Sequencing analysis indicated that the isolates shared 98.5%-99.8% sequence identity to the 16S rDNA gene sequences of the . Streptomyces taxons. The antimicrobial substances were extracted using hexane and ethyl acetate from spent medium in which strains were cultivated at 30°C for five days. The antimicrobial activity was assessed using broth micro dilution technique. Each of the culture extracts from these five strains showed a typical polyene-like property. The lowest minimum inhibitory concentrations of ethyl acetate extracts against . Escherichia coli and . Curvularia lunata were 67.5 and 125.0 μg/mL, respectively. Conclusion: It can be concluded that hexane and ethyl acetate soluble extracellular products of novel isolates are effective against pathogenic bacteria and fungi. © 2012 Asian Pacific Tropical Biomedical Magazine.

Joseph B.,The Interdisciplinary Center | Nair V.M.,Malankara Catholic College
International Journal of Pharma and Bio Sciences | Year: 2013

Presently, researchers have been given remarkable attention to complementary and alternative medicine to deal with cancer treatment from medicinal plants mainly due to its fewer side effects and ease availability. Several scientific studies deep- rooted the anti- cancerous property of Ocimum sanctum Linn., a traditional medicinal plant commonly known as Tulsi. The chemopreventive and radiopreventive property of O. sanctum along with its anti- oxidant, anti- inflammatory and anti- stress property reside as a backbone for it anti- cancerous effect. It is demonstrated that the cornerstone behind this effect is the various phytochemical constituents such as eugenol, orientin, vicenin- 2, linolenic acid and ursolic acid. The present review is an effort to amalgamate the various scientific studies underlying the anti-cancerous effect of O. sanctum under one roof. In this review, the anti-cancerous activity of O. sanctum in numerous cancers such as lung, skin, oral, cervical, gastric, breast and prostate were comprehensively represented.

Bright K.C.,Malankara Catholic College | Freeda T.H.,Physics Research Center
Physica B: Condensed Matter | Year: 2010

Single crystals of l-alanine cadmium chloride (LACC), an organometallic nonlinear optical material, have been grown by the slow evaporation technique. The grown crystals were subjected to various characterization techniques, such as single crystal and powder XRD, FTIR, UVvis and TGA-DTA. The mechanical properties of the crystals show that this material belongs to the category of hard materials. Second harmonic generation was confirmed by the Kurtz and Perry powder technique. Electrical parameters, such as dielectric constant, dielectric loss, ac and dc conductivity and their corresponding activation energies have been studied. The low dielectric constant and dielectric loss suggest that this material is a good candidate for micro-electronic applications. © 2010 Elsevier B.V. All rights reserved.

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