Phenotypic plasticity and longevity in plants and animals: cause and effect?

Immobile plants and immobile modular animals outlive unitary animals. This paper discusses competing but not necessarily mutually exclusive theories to explain this extreme longevity, especially from the perspective of phenotypic plasticity. Stem cell immortality, vascular autonomy, and epicormic branching are some important features of the phenotypic plasticity of plants that contribute to their longevity. Monocarpy versus polycarpy can also influence the kind of senescent processes experienced by plants. How density-dependent phenomena affecting the establishment of juveniles in these immobile organisms can influence the evolution of senescence, and consequently longevity, is reviewed and discussed. Whether climate change scenarios will favour long-lived or short-lived organisms, with their attendant levels of plasticity, is also presented.

Expression of VP1 protein of serotype A and O of foot-and-mouth disease virus in transgenic sunnhemp plants and its immunogenicity for guinea pigs

Recently, transgenic plants expressing immunogenic proteins of foot-and-mouth disease virus (FMDV) have been used as oral or parenteral vaccines against foot-and-mouth disease (FMD). They exhibit advantages like cost effectiveness, absence of processing, thermostability, and easy oral application. FMDV VP1 protein of single serotype has been mostly used as immunogen. Here we report the development of a bivalent vaccine with tandem-linked VP1 proteins of two serotypes, A and O, present in transgenic forage crop Crotalaria juncea. The expression of the bivalent protein in the transgenic plants was confirmed by Western blot analysis. Guinea pig reacted to orally or parenterally applied vaccine by humoral as well as cell-mediated immune responses including serum antibodies and stimulated lymphocytes, respectively. The vaccine protected the animals against a challenge with the virus of serotype A as well as O. This is the first report on the development of a bivalent FMD vaccine using a forage crop.

Context dependency of rewards and services in an Indian ant-plant interaction: southern sites favour the mutualism between plants and ants

Protection-based ant-plant mutualisms may vary in strength due to differences in ant rewards, abundance of protective ants and herbivory pressure. We investigated geographical and temporal variation in host plant traits and herbivory pressure at five sites spanning the distribution range of the myrmecophyte Humboldtia brunonis (Fabaceae) in the Indian Western Ghats. Southern siteshad, onaverage, 2.4 times greater abundance of domatia-bearing individuals, 1.6 times greater extrafloral nectary numbers per leaf, 1.2 times larger extrafloral nectary sizes, 2.2 times greater extrafloral nectar (EFN) volumes and a two-fold increase in total amino acid and total sugar concentrations in EFN compared with northern sites. Astrong protection-based mutualismwith ants occurred at only one southern site where herbivory was highest, suggesting that investments in attracting ants correlate with anti-herbivore benefits gained from the presence of protective ants. Our results confirm a temporally stable north-south gradient in myrmecophytic traits in this ant-plant as several of these traits were re-sampled after a 5-y interval. However, the chemical composition of EFN varied at both spatial and short-term temporal scales suggesting that only repeated measurements of rewards such as EFN can reveal the real spectrum of trait variation in an ant-plant mutualistic system.

How mutualisms between plants and insects are stabilized

While the idea of cooperation between individuals of a species has received considerable attention, how mutualistic interactions between species can be protected from cheating by partners in the interaction has only recently been examined from theoretical and empirical perspectives. This paper is a selective review of the recent literature on host sanctions, partner-fidelity feedback and the concept of punishment in such mutualisms. It describes new ideas, borrowed from microeconomics, such as screening theory with and without competition between potential partners for a host. It explores mutualism-stabilizing mechanisms using examples from interactions between figs and fig wasps, and those between ants and plants. It suggests new avenues for research.

Of plants and pikas: evidence for a climate-mediated decline in forage and cache quality

Background: Animals that hoard food to mediate seasonal deficits in resource availability might be particularly vulnerable to climate-mediated reductions in the quality and accessibility of food during the caching season. Central-place foragers might be additionally impacted by climatic constraints on their already restricted foraging range. Aims: We sought evidence for these patterns in a study of the American pika (Ochotona princeps), a territorial, central-place forager sensitive to climate. Methods: Pika food caches and available forage were re-sampled using historical methods at two long-term study sites, to quantify changes over two decades. Taxa that changed in availability or use were analysed for primary and secondary metabolites. Results: Both sites trended towards warmer summers, and snowmelt trended earlier at the lower latitude site. Graminoid cover increased at each site, and caching trends appeared to reflect available forage rather than primary metabolites. Pikas at the lower latitude site preferred species higher in secondary metabolites, known to provide higher-nutrient winter forage. However, caching of lower-nutrient graminoids increased in proportion with graminoid availability at that site. Conclusions: If our results represent trends in climate, cache quality and available forage, we predict that pikas at the lower latitude site will soon face nutritional deficiencies.

Climate response to physiological forcing of carbon dioxide simulated by the coupled Community Atmosphere Model (CAM3.1) and Community Land Model (CLM3.0)

Increasing concentrations of atmospheric CO2 decrease stomatal conductance of plants and thus suppress canopy transpiration. The climate response to this CO2-physiological forcing is investigated using the Community Atmosphere Model version 3.1 coupled to Community Land Model version 3.0. In response to the physiological effect of doubling CO2, simulations show a decrease in canopy transpiration of 8%, a mean warming of 0.1K over the land surface, and negligible changes in the hydrological cycle. These climate responses are much smaller than what were found in previous modeling studies. This is largely a result of unrealistic partitioning of evapotranspiration in our model control simulation with a greatly underestimated contribution from canopy transpiration and overestimated contributions from canopy and soil evaporation. This study highlights the importance of a realistic simulation of the hydrological cycle, especially the individual components of evapotranspiration, in reducing the uncertainty in our estimation of climatic response to CO2-physiological forcing. Citation: Cao, L., G. Bala, K. Caldeira, R. Nemani, and G.Ban-Weiss (2009), Climate response to physiological forcing of carbon dioxide simulated by the coupled Community Atmosphere Model (CAM3.1) and Community Land Model (CLM3.0).

Universalization of access to modern energy services in Indian households-Economic and policy analysis

Provision of modern energy services for cooking (with gaseous fuels)and lighting (with electricity) is an essential component of any policy aiming to address health, education or welfare issues; yet it gets little attention from policy-makers. Secure, adequate, low-cost energy of quality and convenience is core to the delivery of these services. The present study analyses the energy consumption pattern of Indian domestic sector and examines the urban-rural divide and income energy linkage. A comprehensive analysis is done to estimate the cost for providing modern energy services to everyone by 2030. A public-private partnership-driven business model, with entrepreneurship at the core, is developed with institutional, financing and pricing mechanisms for diffusion of energy services. This approach, termed as EMPOWERS (entrepreneurship model for provision of wholesome energy-related basic services), if adopted, can facilitate large-scale dissemination of energy-efficient and renewable technologies like small-scale biogas/biofuel plants, and distributed power generation technologies to provide clean, safe, reliable and sustainable energy to rural households and urban poor. It is expected to integrate the processes of market transformation and entrepreneurship development involving government, NGOs, financial institutions and community groups as stakeholders. (C) 2009 Elsevier Ltd. All rights reserved.

Fish stupefying plants used by the Gond tribal of Mendha village of Central India

Fish stupefying plants and their methods of use by the Gond people of Mendha village of the Gadchiroli district in Maharashtra state have been documented. For the purpose of validation, literature survey revels that many fish stupefying plants being used since long time by local people are recently well tested by many workers and are found to have many important medicinal properties. It was also observed that herbal fish stupefying agents are excellent means of fishing, which do not kill whole fish stock like chemicals.

Evolution, Homology Conservation, and Identification of Unique Sequence Signatures in GH19 Family Chitinases

The discovery of GH (Glycoside Hydrolase) 19 chitinases in Streptomyces sp. raises the possibility of the presence of these proteins in other bacterial species, since they were initially thought to be confined to higher plants. The present study mainly concentrates on the phylogenetic distribution and homology conservation in GH19 family chitinases. Extensive database searches are performed to identify the presence of GH19 family chitinases in the three major super kingdoms of life. Multiple sequence alignment of all the identified GH19 chitinase family members resulted in the identification of globally conserved residues. We further identified conserved sequence motifs across the major sub groups within the family. Estimation of evolutionary distance between the various bacterial and plant chitinases are carried out to better understand the pattern of evolution. Our study also supports the horizontal gene transfer theory, which states that GH19 chitinase genes are transferred from higher plants to bacteria. Further, the present study sheds light on the phylogenetic distribution and identifies unique sequence signatures that define GH19 chitinase family of proteins. The identified motifs could be used as markers to delineate uncharacterized GH19 family chitinases. The estimation of evolutionary distance between chitinase identified in plants and bacteria shows that the flowering plants are more related to chitinase in actinobacteria than that of identified in purple bacteria. We propose a model to elucidate the natural history of GH19 family chitinases.

Investigations on the RNA binding and phosphorylation of groundnut bud necrosis virus nucleocapsid protein

Groundnut bud necrosis virus belongs to the genus Tospovirus, infects a wide range of crop plants and causes severe losses. To understand the role of the nucleocapsid protein in the viral life cycle, the protein was overexpressed in E. coli and purified by Ni-NTA chromatography. The purified N protein was well folded and was predominantly alpha-helical. Deletion analysis revealed that the C-terminal unfolded region of the N protein was involved in RNA binding. Furthermore, the N protein could be phosphorylated in vitro by Nicotiana benthamiana plant sap and by purified recombinant kinases such as protein kinase CK2 and calcium-dependent protein kinase. This is the first report of phoshphorylation of a nucleocapsid protein in the family Bunyaviridae. The possible implications of the present findings for the viral life cycle are discussed.

In praise of H2O2, the versatile ROS, and its vanadium complexes

Hydrogenperoxide (H2O2) is generated in mitochondria in aerobic cells as a minor product of electron transport, is inhibited selectively by phenolic acids (in animals) or salicylhydroxamate (in plants) and is regulated by hormones and environmental conditions. Failure to detect this activity is due to presence of H2O2-consuming reactions or inhibitors present in the reaction mixture. H2O2 has a role in metabolic regulation and signal transduction reactions. A number of enzymes and cellular activities are modified, mostly by oxidizing the protein-thiol groups, on adding H2O2 in mM concentrations. On complexing with vanadate, also occurring in traces, H2O2 forms diperoxovanadate (DPV), stable at physiological pH and resistant to degradation by catalase. DPV was found to substitute for H2O2 at concentrations orders of magnitude lower, and in presence of catalase, as a substrate for user reaction, horseradish peroxidase (HRP), and in inactivating glyceraldehyde-3-phosphate dehydrogenase. superoxide dismutase (SOD)-sensitive oxidation of NADH was found to operate as peroxovanadate cycle using traces of DPV and decameric vanadate (V-10) and reduces O-2 to peroxide (DPV in presence of free vanadate). This offers a model for respiratory burst. Diperoxovanadate reproduces several actions of H2O2 at low concentrations: enhances protein tyrosine phosphorylation, activates phospholipase D, produces smooth muscle contraction, and accelerates stress induced premature senescence (SIPS) and rounding in fibroblasts. Peroxovanadates can be useful tools in the studies on H2O2 in cellular activities and regulation.

Euglena sp as a suitable source of lipids for potential use as biofuel and sustainable wastewater treatment

Prolific algal growth in sewage ponds with high organic loads in the tropical regions can provide cost-effective and efficient wastewater treatment and biofuel production. This work examines the ability of Euglena sp. growing in wastewater ponds for biofuel production and treatment of wastewater. The algae were isolated from the sewage treatment plants and were tested for their nutrient removal capability. Compared to other algae, Euglena sp. showed faster growth rates with high biomass density at elevated concentrations of ammonium nitrogen (NH4-N) and organic carbon (C). Profuse growth of these species was observed in untreated wastewaters with a mean specific growth rate (mu) of 0.28 day(-1) and biomass productivities of 132 mg L-1 day(-1). The algae cultured within a short period of 8 days resulted in the 98 % removal of NH4-N, 93 % of total nitrogen 85 % of ortho-phosphate, 66 % of total phosphate and 92 % total organic carbon. Euglenoids achieved a maximum lipid content of 24.6 % (w/w) with a biomass density of 1.24 g L-1 (dry wt.). Fourier transform infrared spectra showed clear transitions in biochemical compositions with increased lipid/protein ratio at the end of the culture. Gas chromatography and mass spectrometry indicated the presence of high contents of palmitic, linolenic and linoleic acids (46, 23 and 22 %, respectively), adding to the biodiesel quality. Good lipid content (comprised quality fatty acids), efficient nutrient uptake and profuse biomass productivity make the Euglena sp. as a viable source for biofuel production in wastewaters.

On existence of periodic solutions for stable interval plants with odd, sector type nonlinearities

In several systems, the physical parameters of the system vary over time or operating points. A popular way of representing such plants with structured or parametric uncertainties is by means of interval polynomials. However, ensuring the stability of such systems is a robust control problem. Fortunately, Kharitonov's theorem enables the analysis of such interval plants and also provides tools for design of robust controllers in such cases. The present paper considers one such case, where the interval plant is connected with a timeinvariant, static, odd, sector type nonlinearity in its feedback path. This paper provides necessary conditions for the existence of self sustaining periodic oscillations in such interval plants, and indicates a possible design algorithm to avoid such periodic solutions or limit cycles. The describing function technique is used to approximate the nonlinearity and subsequently arrive at the results. Furthermore, the value set approach, along with Mikhailov conditions, are resorted to in providing graphical techniques for the derivation of the conditions and subsequent design algorithm of the controller.

Decentralized demand-supply matching using community microgrids and consumer demand response: A scenario analysis

Developing countries constantly face the challenge of reliably matching electricity supply to increasing consumer demand. The traditional policy decisions of increasing supply and reducing demand centrally, by building new power plants and/or load shedding, have been insufficient. Locally installed microgrids along with consumer demand response can be suitable decentralized options to augment the centralized grid based systems and plug the demand-supply gap. The objectives of this paper are to: (1) develop a framework to identify the appropriate decentralized energy options for demand supply matching within a community, and, (2) determine which of these options can suitably plug the existing demand-supply gap at varying levels of grid unavailability. A scenario analysis framework is developed to identify and assess the impact of different decentralized energy options at a community level and demonstrated for a typical urban residential community Vijayanagar, Bangalore in India. A combination of LPG based CHP microgrid and proactive demand response by the community is the appropriate option that enables the Vijayanagar community to meet its energy needs 24/7 in a reliable, cost-effective manner. The paper concludes with an enumeration of the barriers and feasible strategies for the implementation of community microgrids in India based on stakeholder inputs. (C) 2014 Elsevier Ltd. All rights reserved.