Khadeer Ahamed M.B.,University of Agricultural Sciences, Bangalore |
Krishna V.,Kuvempu University |
Dandin C.J.,Indian Institute of Science
European Journal of Pharmacology | Year: 2010
Grewia tiliaefolia is widely used in traditional Indian medicines to cure jaundice, biliousness, dysentery and the diseases of blood. Bioassay-guided fractionation of methanolic extract of the G. tiliaefolia bark has resulted in the isolation of D-erythro-2-hexenoic acid γ-lactone (EHGL) and gulonic acid γ-lactone (GAGL). Hepatoprotective activity of the methanolic extract and the isolated constituents were evaluated against CCl4-induced hepatotoxicity in rats. The treatment with methanolic extract, EHGL and GAGL at oral doses of 100, 150 and 60 mg/kg respectively with concomitant CCl4 intraperitoneal injection (1 ml/kg) significantly reduced the elevated plasma levels of aminotransferases, alkaline phosphatase and the incidence of liver necrosis compared with the CCl4-injected group without affecting the concentrations of serum bilirubin and hepatic markers. EHGL and GAGL significantly inhibited the elevated levels of thiobarbituric acid reactive substances and glutathione in liver homogenates. Histology of the liver tissues of the extract and isolated constituents treated groups showed the presence of normal hepatic cords, absence of necrosis and fatty infiltration as similar to the normal control. The results revealed that the hepatoprotective activity of EHGL is significant as similar to the standard drug silymarin. To clarify the influence of the extract and isolated constituents on the protection of oxidative-hepatic damage, we examined in vitro antioxidant properties of the test compounds. The extract and the constituents showed significant free radical scavenging activity. These results suggest that the extract as well as the constituents could protect the hepatocytes from CCl4-induced liver damage perhaps, by their anti-oxidative effect on hepatocytes, hence eliminating the deleterious effects of toxic metabolites from CCl4. © 2009 Elsevier B.V. All rights reserved.
Viraktamath C.A.,University of Agricultural Sciences, Bangalore
Zootaxa | Year: 2016
Species of Signoretia Stål from the Oriental region are reviewed and types of five species described by Baker, two species described by Distant and one species described by Schmidt are illustrated. A checklist of 20 species of the genus from the Oriental region including 9 new species is given. The new species described and illustrated are Signoretia dulitensis sp. nov. (Malaysia: Mt Dulit), S. lunglei sp. nov. (India: Mizoram), S. mishmiensis sp. nov. (Myanmar: Mishmi Hills), S. quoinensis sp. nov. (Malaysia: Quoin Hill), S. rubra sp. nov. (Thailand: Chiang Mai), S. sahyadrica sp. nov. (India: Kerala), S. similaris sp. nov. (Vietnam: Fyan), S. sinuata sp. nov. (India: West Bengal) and S. takiyae sp. nov. (India: Andaman Is.). Both S. aureola Distant and S. maculata Baker are redescribed and illustrated. Lectotypes are designated for S. greeni Distant and S. aureola Distant.
Viraktamath C.A.,University of Agricultural Sciences, Bangalore |
Dietrich C.H.,University of Illinois at Urbana - Champaign
Zootaxa | Year: 2011
Sweta gen. n. is described and illustrated based on type species S. hallucinata sp. n. from northeast India and Thailand and placed in the typhlocybine tribe Dikraneurini. The new genus is unique among known Typhlocybinae in having the pronotum enlarged and extended to the scutellar suture. This feature is characteristic of the related subfamily Signoretii-nae, but among other subfamilies is restricted to a few brachypterous forms. Copyright © 2011 - Magnolia Press.
Aghera N.,Tata Institute of Fundamental Research |
Earanna N.,University of Agricultural Sciences, Bangalore |
Udgaonkar J.B.,Tata Institute of Fundamental Research
Biochemistry | Year: 2011
To improve our understanding of the contributions of different stabilizing interactions to protein stability, including that of residual structure in the unfolded state, the small sweet protein monellin has been studied in both its two variant forms, the naturally occurring double-chain variant (dcMN) and the artificially created single-chain variant (scMN). Equilibrium guanidine hydrochloride-induced unfolding studies at pH 7 show that the standard free energy of unfolding, ΔG°U, of dcMN to unfolded chains A and B and its dependence on guanidine hydrochloride (GdnHCl) concentration are both independent of protein concentration, while the midpoint of unfolding has an exponential dependence on protein concentration. Hence, the unfolding of dcMN like that of scMN can be described as two-state unfolding. The free energy of dissociation, ΔG°d, of the two free chains, A and B, from dcMN, as measured by equilibrium binding studies, is significantly lower than ΔG°U, apparently because of the presence of residual structure in free chain B. The value of ΔG°U, at the standard concentration of 1 M, is found to be ∼5.5 kcal mol-1 higher for dcMN than for scMN in the range from pH 4 to 9, over which unfolding appears to be two-state. Hence, dcMN appears to be more stable than scMN. It seems that unfolded scMN is stabilized by residual structure that is absent in unfolded dcMN and/or that native scMN is destabilized by strain that is relieved in native dcMN. The value of ΔG°U for both protein variants decreases with an increase in pH from 4 to 9, apparently because of the thermodynamic coupling of unfolding to the protonation of a buried carboxylate side chain whose pKa shifts from 4.5 in the unfolded state to 9 in the native state. Finally, it is shown that although the thermodynamic stabilities of dcMN and scMN are very different, their kinetic stabilities with respect to unfolding in GdnHCl are very similar. © 2011 American Chemical Society.
Managave S.R.,Physical Research Laboratory |
Sheshshayee M.S.,University of Agricultural Sciences, Bangalore |
Borgaonkar H.P.,Indian Institute of Tropical Meteorology |
Ramesh R.,Physical Research Laboratory
Geophysical Research Letters | Year: 2010
Intra-annual variations in the cellulose oxygen isotopic composition (δ18O) of several annual growth rings of three teak (Tectona grandis L.F.) trees from central India show a clear seasonal cycle with higher values in the early and late growing seasons and lower values in the middle. This cycle is useful to identify growth occurring during different phases of the growing season. Relative humidity (RH) appears to control the intra-annual δ18O variations rather than rainfall, and therefore past break-monsoon conditions associated with lower RH, could be detected by high resolution sub-sampling of annual rings for δ18O analysis. Copyright © 2010 by the American Geophysical Union.
Murugan R.,University of Kassel |
Kumar S.,University of Agricultural Sciences, Bangalore
Biology and Fertility of Soils | Year: 2013
Amino sugars, as a microbial residue biomarker, are highly involved in microbial-mediated soil organic matter formation. However, accumulation of microbial biomass and responses of bacterial and fungal residues to the management practices are different and poorly characterized in rice soils. The objectives of this study were to evaluate the effects of mineral fertiliser (MIN), farmyard manure (FYM) and groundnut oil cake (GOC) on crop yield and co-accumulation of microbial residues and microbial biomass under rice-monoculture (RRR) and rice-legume-rice (RLR) systems. In the organic fertiliser treatments and RLR, rice grain yield and stocks of soil and microbial nutrients were significantly higher than those of the MIN treatment and RRR, respectively. The increased presence of saprotrophic fungi in the organic fertiliser treatments and RRR was indicated by significantly increased ergosterol/Cmic ratio and extractable sulphur. In both crop rotation systems, the long-term application of FYM and GOC led to increased bacterial residues as indicated by greater accumulation of muramic acid. In contrast, the higher fungal C/bacterial C ratio and lower ergosterol/Cmic ratio in the MIN treatment, is likely caused by a shift within the fungal community structure towards ergosterol-free arbuscular mycorrhizal fungi (AMF). The organic fertiliser treatments contributed 22 % more microbial residual C to soil organic C compared to the MIN treatment. Our results suggest that the negative relationship between the ratios ergosterol/Cmic and fungal C/bacterial C encourages studying responses of both saprotrophic fungi and AMF when assessing management effects on the soil microbial community. © 2013 Springer-Verlag Berlin Heidelberg.
Bhaskaran S.,University of Agricultural Sciences, Bangalore |
Savithramma D.L.,University of Agricultural Sciences, Bangalore
Journal of Experimental Botany | Year: 2011
Salinity is one of the major abiotic stresses affecting plant productivity. Tomato (Solanum lycopersicum L.), an important and widespread crop in the world, is sensitive to moderate levels of salt in the soil. To generate tomato plants that can adapt to saline soil, AVP1, a vacuolar H +- pyrophosphatase gene from Arabidopsis thaliana, and PgNHX1, a vacuolar Na +/H + antiporter gene from Pennisetum glaucum, were co-expressed by Agrobacterium tumefaciens-mediated transformation. A sample of transformants was self-pollinated, and progeny were evaluated for salt tolerance in vitro and in vivo. It is reported here that co-expression of AVP1 and PgNHX1 confers enhanced salt tolerance to the transformed tomato compared with the AVP1 and PgNHX1 single gene transgenic plants and the wild-type. These transgenic plants grew well in the presence of 200mM NaCl while wild-type plants exhibited chlorosis and died within 3 weeks. The transgenic line co-expressing AVP1 and PgNHX1 retained more chlorophyll and accumulated 1.4 times more proline as a response to stress than single gene transformants. Moreover, these transgenic plants accumulated a 1.5 times higher Na + content in their leaf tissue than the single gene transformants. The toxic effect of Na + accumulation in the cytosol is reduced by its sequestration into the vacuole. The physiological analysis of the transgenic lines clearly demonstrates that co-expression of AVP1 and PgNHX1 improved the osmoregulatory capacity of double transgenic lines by enhanced sequestration of ions into the vacuole by increasing the availability of protons and thus alleviating the toxic effect of Na +. © 2011 The Author.
Pruthvi V.,University of Agricultural Sciences, Bangalore |
Narasimhan R.,University of Agricultural Sciences, Bangalore |
Nataraja K.N.,University of Agricultural Sciences, Bangalore
PLoS ONE | Year: 2014
Drought, salinity and extreme temperatures are the most common abiotic stresses, adversely affecting plant growth and productivity. Exposure of plants to stress activates stress signalling pathways that induce biochemical and physiological changes essential for stress acclimation. Stress tolerance is governed by multiple traits, and importance of a few traits in imparting tolerance has been demonstrated. Under drought, traits linked to water mining and water conservation, water use efficiency and cellular tolerance (CT) to desiccation are considered to be relevant. In this study, an attempt has been made to improve CT in drought hardy crop, peanut (Arachis hypogaea L., cv. TMV2) by co-expressing stress-responsive transcription factors (TFs), AtDREB2A, AtHB7 and AtABF3, associated with downstream gene expression. Transgenic plants simultaneously expressing these TFs showed increased tolerance to drought, salinity and oxidative stresses compared to wild type, with an increase in total plant biomass. The transgenic plants exhibited improved membrane and chlorophyll stability due to enhanced reactive oxygen species scavenging and osmotic adjustment by proline synthesis under stress. The improvement in stress tolerance in transgenic lines were associated with induced expression of various CT related genes like AhGlutaredoxin, AhAldehyde reductase, AhSerine threonine kinase like protein, AhRbx1, AhProline amino peptidase, AhHSP70, AhDIP and AhLea4. Taken together the results indicate that co-expression of stress responsive TFs can activate multiple CT pathways, and this strategy can be employed to improve abiotic stress tolerance in crop plants. ©2014 Pruthvi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Kumaraswamy S.,University of Agricultural Sciences, Bangalore |
Udayakumar M.,University of Agricultural Sciences, Bangalore
Biodiversity and Conservation | Year: 2011
Among the conservation initiatives, biodiversity banking is a strategic new concept that calls for advocacy by the researchers, conservationists, policy planners and business corporate houses to enhance the conservational behaviour of the stakeholders. The concept has dual benefits of restoration of livelihood support systems and conservation of biodiversity that provides ecological services and economic benefits to civil society. Currently, lack of defined guidelines with robust valuation and incentive mechanism for biodiversity banking has resulted in 'business as usual' situation especially in developing and under developed countries. There is need for re-defining the country level biodiversity banking guidelines for the effective private-government-stakeholder participation. Furthermore, the mechanism must consider using robust scientific database of inter-disciplinary nature and suitably adopt the modalities of successful case studies to overcome the flaws/risks. Biodiversity banking is a realizable concept in developing and resource poor countries as additional livelihood support system through the market of accrued ecosystem services linked to conservation behaviour of stakeholders. © 2011 Springer Science+Business Media B.V.
Viraktamath C.A.,University of Agricultural Sciences, Bangalore
Zootaxa | Year: 2011
The tribe Agalliini of the subfamily Megophthalminae is revised for the Oriental and Australian regions. Fifteen genera and 86 species have been recognized including 6 new genera, 40 new species, 7 new synonyms and 9 new combinations. The new genera and species described are Austroagallia balii sp. nov. (Indonesia: Bali Is.), A. distanti sp. nov. (India:Karnataka), A. prachuabensis sp. nov. (India, Thailand), Formallia gen. nov., F. ishiharai sp. nov.(Taiwan), F. longipenis sp. nov. (Taiwan), F. longistyla sp. nov. (Taiwan), F. rugosa sp. nov. (Taiwan), F. truncata sp. nov. (type sepcies) (Taiwan), Hemagallia gen. nov. (type-species: Agallia plotina Distant), Ianagallia gen. nov. (type-species Austroagallia bifurcata Sawai Singh & Gill), Igerna aurora sp. nov. (Sunda Is, Timor Is.), I. darjeelingensis sp. nov. (India: Sikkim, West Bengal), I. delineata sp. nov. (India: Tamil Nadu), I. himalayensis sp. nov. (India: West Bengal), I. keyae sp. nov. (India: Sikkim), I. priyankae sp. nov. (India: Himachal Pradesh, Meghalaya. Nepal), I. quinlani sp. nov. (Nepal), I. sikkima sp. nov. (India: Sikkim), I. wilsoni sp. nov. (India: West Bengal), Japanagallia asymmetrica sp. nov. (China: Fukien), J. curvata sp. nov. (China: Fukien), J. javana sp. nov. (Indonesia: Java), J. longipenis sp. nov. (China: Fukien), J. malaisei sp. nov. (Myanmar), J. mussooriensis sp. nov. (India: Uttar Pradesh), J. neotappana sp. nov. (China: Fukien), J. nepalensis sp. nov. (Nepal), J. peculiaris sp. nov. (Nepal), J. sumatrana sp. nov. (Indonesia: Sumatra), J. yoshimotoi sp. nov. (Taiwan), Nandigallia gen. nov. N. matai sp. nov. (India: West Bengal; China: Fukien), N. nandiensis sp. nov. (type-species) (India: Karnataka, Maharashtra), Paulagallia gen. nov., P. maai sp. nov. (Malaysia: Borneo: Sabah), P. punctata sp. nov. (type-species)( Malaysia: Borneo: Sabah), Sangeeta gen. nov. S. dentata sp. nov. (Indonesia: Pahang), S. dlabolai sp. nov. (Laos), S. fyanensis sp. nov. (Vietnam), S. linnavuorii sp. nov. (Vietnam), S. nigra sp. nov. (Indonesia: Java), S. quadriloba sp. nov. (Indonesia: Sumatra), S. sadongensis sp. nov. (type-species) (Malaysia: Sadong) and S. sarawakensis sp. nov. (Malaysia: Borneo: Sarawak) The following new combinations are proposed: Anaceratagallia srinagarensis (Kameswara Rao & Ramakrishnan) comb. nov. (Agallia), Hemagallia biplagiata (Melichar) comb. nov. (Agallia), Hemagallia plotina (Distant) comb. nov. (Agallia), Ianagallia bifurcata (Sawai Singh & Gill) comb. nov. (Austroagallia), Igerna atrovenosa (Melichar) comb. nov. (Agallia), Igerna fasciata (Osborn) comb. nov. (Agalliopsis), Igerna quadrinotata (Melichar) comb. nov. (Agallia), Igerna nigrita (Melichar) comb. nov. (Oncopsis) and Igerna violacea (Distant) comb. nov. (Nehela). The following species are treated as new synonyms: Agallia pseudorobusta Kameswara Rao & Ramakrishnan syn. nov. of Anaceratagallia cuspidata Dlabola; Anaceratagallia delhiensis Kameswara Rao & Ramakrishnan syn. nov. of Anaceratagallia robusta Pruthi; Agallia campbelli Distant syn. nov. and Agallia janaka Distant syn. nov. of Hemagallia biplagiata (Melichar); Agallia rugosa Distant syn. nov. and Agallia bhuntra Sawai Singh syn. nov. of Hemagallia plotina (Distant), Austroagallia bisinuata Viraktamath & Viraktamath syn. nov. of Igerna quadrinotata (Melichar), and Dryodurgades bifurcatus Cai & Shen syn. nov. of Dryodurgades formosana (Matsumura). Most of these taxa are described and illustrated. Keys to genera and species are also included. Copyright © 2011 . Magnolia Press.