Endophytic bacteria colonizing the shoot-tips of banana cv. Grand Naine were isolated and tested for the antagonistic activity against the Panama wilt pathogen Fusarium oxysporum f. sp. cubense (Foc). Pre-isolation, t...Endophytic bacteria colonizing the shoot-tips of banana cv. Grand Naine were isolated and tested for the antagonistic activity against the Panama wilt pathogen Fusarium oxysporum f. sp. cubense (Foc). Pre-isolation, the suckers were given extensive disinfection treatments and the homogenate from the excised shoot-tip portion was plated on nutrient agar (NA) and trypticase soy agar (TSA). This yielded altogether 47 isolates: 26 on NA and 21 on TSA, respectively, from the 10 suckers collected during August to February. The number of bacterial isolates obtained per sucker varied from one to 15 based on colony characteristics registering up to 10 distinct species per shoot-tip based on 16S rRNA sequence analysis. The 47 isolates belonged to 19 genera and 25 species under the phylogenetic classes of Actinobacteria, α- and γ-Proteobacteria and Firmicutes. Actinobacteria constituted the predominant phylum (55% isolates) with the constituent genera of Arthrobacter, Brevibacterium, Corynebacterium, Curtobacterium, Kocuria, Kytococcus, Micrococcus, Naumanella, Rothia and Tessaracoccus spp. and an unidentified isolate belonging to the family Frankiaceae. Proteobacteria constituted the second major phylum (Brevundimonas, Enterobacter, Klebsiella, Pseudomonas, Serratia and Sphingomonas spp.) followed by Firmicutes (Bacillus and Staphylococcus spp.). Antagonistic activity of the endophytes against Foc was tested through agar plate assays (pit and spot applications on fungal lawn) employing potato dextrose agar and NA. Endophytic Pseudomonas aeruginosa (isolate GNS.13.2a) which was associated with a single sucker showed significant growth inhibition effect on Foc while Klebsiella variicola (GNS.13.3a) and Enterobacter cloacae (GNS13.4a) exhibited moderate inhibition. The study brings out considerable sucker to sucker variation in the associated cultivable endophytic bacteria in “Grand Naine” banana and identifies a few bacterial endophytes with biocontrol potential against the devastating Foc pathogen.展开更多
Delonix elata L.is a Ceasalpinaceae species and is traditionally used in India for treatment of skin diseases,liver diseases and rheumatic problems.However,systematic evaluation of its wound healing activity is lackin...Delonix elata L.is a Ceasalpinaceae species and is traditionally used in India for treatment of skin diseases,liver diseases and rheumatic problems.However,systematic evaluation of its wound healing activity is lacking.Thus,in the present study,we aimed to assess the wound healing activity of D.elata stem bark extract(DSE)and its isolated constituent quercetin-3-rhamnopyranosyl-(1-6)glucopyranoside(QRPG)in rats.The formulations effects on wound healing were assessed by the wound contraction rate,epithelialization period,tensile strength,content of the hydroxyproline,hexosamine and uronic acid in granulation tissue,histopathological studies and Col 1α(I)expression level in wound tissue by reverse transcription polymerase chain reaction(RT-PCR)study.The topical application of DSE ointment caused faster epithelialization,significant wound contraction(100%),and better tensile strength(710.5±10.5 g/cm^(2)),while QRPG showed wound epithelialization with 98.2%contraction,better than that of the control group(78.18%).The biochemical analysis of granulation tissue revealed that DSE and QRPG significantly increased hydroxyproline,hexosamine and uronic acid content.A significant increase in the expression of Col 1α(I)was observed in the wound tissue of DSE and QRPG treated rats.DSE and QRPG were shown to enhance wound healing by increasing collagen synthesis through upregulation of Col 1α(I),thus validating ethnomedicinal uses.展开更多
Hydrometeorological models are often evaluated and optimized on the basis of micrometeorological measurements. However, it has been known for more than three decades that surface measurements of sensible and latent he...Hydrometeorological models are often evaluated and optimized on the basis of micrometeorological measurements. However, it has been known for more than three decades that surface measurements of sensible and latent heat energy (LE) are systematically underestimated. We studied this problem using six years of eddy-correlation measurements for four fields (corn, soybean, and prairie) in central Iowa, USA. We recorded major components of the energy equation (i.e. net radiation, sensible heat flux, LE, and soil heat flux, photosynthesis), and indirectly estimated most of the minor components of energy balance (namely storage in the soil, canopy and air). Storage in the canopy was related to leaf area index (LAI) acquired from Moderate Resolution Imaging Spectrometer (MODIS). In this paper, a diagnostic approach is investigated where systematic error is identified first. Three dimensional (3D) plots of the residual of energy equation vs. potential variables indicated the imbalance was largest mainly during the cold non-growing season when the soil was dry. Correlations between energy balance residual (EBR) and energy components showed that soil storage was not precisely estimated. Finally, an a-posteriori analysis (constrained linear multiple regression (CMLR)) was conducted to quantify the contribution of major/minor components of the energy equation towards EBR. The result highlights that the contribution of pertinent components of energy to EBR is mainly controlled by prevailing monthly hydrometeorological conditions;however, precise quantification of causes of imbalance is site-specific. A comparison between the a-posteriori analysis technique and the Bowen-ratio method demonstrates that the Bowen-ratio basically presumes a higher level of underestimation in LE. The results obtained in this study suggest that a-posteriori analysis may offer a superior methodology to correct measured eddy-correlation measurements. Furthermore, the overall trends in the correction of LE measurements suggest that there is a potential for rough monthly corrections of LE, irrespective of the type of crop.展开更多
In this study we explore a method which provides an insight into the effectiveness of various hydrologic models’ routing components based on their ability to accurately represent flood peak times and shapes. The meth...In this study we explore a method which provides an insight into the effectiveness of various hydrologic models’ routing components based on their ability to accurately represent flood peak times and shapes. The method is based on using Cross-Wavelet Transforms to estimate the phase (time) difference between the time series of the observed and the simulated discharges. In this article we evaluate two routing components, the Routing Application for Parallel Computation of Discharge (RAPID), which is based on the simplified Muskingum routing method, and the routing component of the non-linear Hillslope-Link hydrologic Model (HLM) produced in the Iowa Flood Center (IFC). Both routing components are driven by the same source of runoff and used the same channel network to ensure that the discrepancies between the simulated stream discharges are due to channel routing alone. We also explore the suitability of different wavelet shapes for our application, and how the difference in wavelet shape can affect our evaluation results. Unlike the conventional statistical skill scores used to evaluate model performance (e.g. Root Mean Squared Error, correlation coefficient, and Nash Sutcliff efficiency index), which give an estimate of the overall hydrograph performance, our method conveniently provides time-localized information with higher resolution at peak location. We perform our evaluation at multiple stream gauge locations, covering a wide range of scales (700 to 16,862 km2), located in the eastern part of the state of Iowa. Our results show that the proposed wavelet method is effective in evaluating the performance of the routing components in simulating peak times across spatial scales. Generally, the non-linear routing method employed in the HLM outperformed the Muskingum based method employed in RAPID. In addition, our results suggest that the Paul wavelet is more effective in detecting and separating individual peaks than the Morlet wavelet, which in turn leads to a more accurate evaluation of the routing components.展开更多
Western Ghats region of India is one of the biodiversity hotspots of the world. The topography, wide rainfall variation and varied temperature conditions enable inhabitancy of several plant species. This plant wealth ...Western Ghats region of India is one of the biodiversity hotspots of the world. The topography, wide rainfall variation and varied temperature conditions enable inhabitancy of several plant species. This plant wealth is being used in various forms by tribes and natives of the area for centuries. These gain further importance due to the fact that ripe fruits serve as a source of food and medicine to tribes throughout the year. These wild fruits are source of minerals and vitamins in the diet of the rural people. The potential productivity and floristic diversity of the area have attracted the experts. There are more than 50 wild edible fruit species are available in Western Ghats region. These belong to 25 families and 38 genera. Out of the 25 families, the important ones as a source of fruits are Apocynaceae, Anacardiaceae, Euphorbiaceae, Moraceae, Sapotaceae and Sapindaceae. The fruiting period of different species ranges between two and six months. The highest number of species mature from April to May. The availability of these fruits reduces after October. Some of these fruits, such as Mangifera indica, Artocarpus heterophyllus, Carissa carandas, Emblica officinalis and Syzygium cuminii, have been given emphasis in order to identify high yield and high fruit quality clones and standardization of production technologies. The collection, conservation and utilization on some of the fruits, such as Garcinia indica and Garcinia gummigutta have started at various research organizations. Some other fruits, namely Chrysophyllum roxburghii （Family Sapotaceae）, Canthium parviflora Lamk syn. Plectronia parviflora （Lam.） Bedd. （Family Rubiaceae）, Elaeagnus conferta Roxbsyn, Elaeagnus latifolia L. （Family Elaeagnaceae）, Securina leucopyrus syn. Flueggea leucopyrus （Family Euphorbiaceae）, Elaeocarpus tuberculatus Roxb. （Family Elaeocarpaceae）, Nephelium stipulacum Bedd. syn. Doratoxylon stipulatum （Family Sapindaceae） have potential for commercial cultivation. Thus, attempts were made with the objective of recording availability of these species, proximate analysis and their on farm and off farm conservation at Central Horticultural Experiment Station （CHES）. Few plants were also provided to local growers on farm conservation. The continuous depletion of forest and the increasing human disturbance resulted in losses of these species. There is need to conserve these fruits for future.展开更多
Benoxacor is a safener added to current-use herbicide formulations to protect the target crop from herbicidal toxicity.It is an emerging environmental contaminant that has been detected in surface waters,raising the p...Benoxacor is a safener added to current-use herbicide formulations to protect the target crop from herbicidal toxicity.It is an emerging environmental contaminant that has been detected in surface waters,raising the possibility of human exposure via drinking water.Because it is not subject to the same regulations as active pesticide ingredients,its metabolism and toxicity in humans have not been studied.Here we investigate the enantioselective metabolism of benoxacor in human subcellular fractions.Pooled human liver microsomes(pHLM)and cytosol(pHLC)were incubated with racemic benoxacor for up to 30-min.Gas chromatographic analyses were used to measure the enantioselective depletion of benoxacor.pHLMs with and without nicotinamide adenine dinucleotide phosphate(NADPH,co-factor for cytochrome P450 enzymes[CYPs])and pHLC with glutathione(GSH,co-factor for glutathione Stransferases[GSTs])metabolized benoxacor.These results demonstrate that microsomal CYPs,microsomal carboxylesterase(CESs),and cytosolic GSTs metabolize benoxacor.Females were predicted to have a higher clearance of benoxacor by GSTs than males.Male and female pHLM incubations with NADPH showed enrichment of the first eluting benoxacor enantiomer(E1-benoxacor).pHLM incubations without NADPH and pHLC incubations with GSH showed an enrichment of the second eluting enantiomer of benoxacor(E2-benoxacor).Our results indicate that human hepatic microsomal and cytosolic enzymes enantioselectively metabolize benoxacor,a fact that needs to be considered when investigating human exposures and toxicities of benoxacor.展开更多
文摘Endophytic bacteria colonizing the shoot-tips of banana cv. Grand Naine were isolated and tested for the antagonistic activity against the Panama wilt pathogen Fusarium oxysporum f. sp. cubense (Foc). Pre-isolation, the suckers were given extensive disinfection treatments and the homogenate from the excised shoot-tip portion was plated on nutrient agar (NA) and trypticase soy agar (TSA). This yielded altogether 47 isolates: 26 on NA and 21 on TSA, respectively, from the 10 suckers collected during August to February. The number of bacterial isolates obtained per sucker varied from one to 15 based on colony characteristics registering up to 10 distinct species per shoot-tip based on 16S rRNA sequence analysis. The 47 isolates belonged to 19 genera and 25 species under the phylogenetic classes of Actinobacteria, α- and γ-Proteobacteria and Firmicutes. Actinobacteria constituted the predominant phylum (55% isolates) with the constituent genera of Arthrobacter, Brevibacterium, Corynebacterium, Curtobacterium, Kocuria, Kytococcus, Micrococcus, Naumanella, Rothia and Tessaracoccus spp. and an unidentified isolate belonging to the family Frankiaceae. Proteobacteria constituted the second major phylum (Brevundimonas, Enterobacter, Klebsiella, Pseudomonas, Serratia and Sphingomonas spp.) followed by Firmicutes (Bacillus and Staphylococcus spp.). Antagonistic activity of the endophytes against Foc was tested through agar plate assays (pit and spot applications on fungal lawn) employing potato dextrose agar and NA. Endophytic Pseudomonas aeruginosa (isolate GNS.13.2a) which was associated with a single sucker showed significant growth inhibition effect on Foc while Klebsiella variicola (GNS.13.3a) and Enterobacter cloacae (GNS13.4a) exhibited moderate inhibition. The study brings out considerable sucker to sucker variation in the associated cultivable endophytic bacteria in “Grand Naine” banana and identifies a few bacterial endophytes with biocontrol potential against the devastating Foc pathogen.
基金partially supported by the Department of Biotechnology,New Delhi,India(Grant no.BT/PR11505/SPD/24/337/2008BT/PR9128/INF/22/190/2013)
文摘Delonix elata L.is a Ceasalpinaceae species and is traditionally used in India for treatment of skin diseases,liver diseases and rheumatic problems.However,systematic evaluation of its wound healing activity is lacking.Thus,in the present study,we aimed to assess the wound healing activity of D.elata stem bark extract(DSE)and its isolated constituent quercetin-3-rhamnopyranosyl-(1-6)glucopyranoside(QRPG)in rats.The formulations effects on wound healing were assessed by the wound contraction rate,epithelialization period,tensile strength,content of the hydroxyproline,hexosamine and uronic acid in granulation tissue,histopathological studies and Col 1α(I)expression level in wound tissue by reverse transcription polymerase chain reaction(RT-PCR)study.The topical application of DSE ointment caused faster epithelialization,significant wound contraction(100%),and better tensile strength(710.5±10.5 g/cm^(2)),while QRPG showed wound epithelialization with 98.2%contraction,better than that of the control group(78.18%).The biochemical analysis of granulation tissue revealed that DSE and QRPG significantly increased hydroxyproline,hexosamine and uronic acid content.A significant increase in the expression of Col 1α(I)was observed in the wound tissue of DSE and QRPG treated rats.DSE and QRPG were shown to enhance wound healing by increasing collagen synthesis through upregulation of Col 1α(I),thus validating ethnomedicinal uses.
文摘Hydrometeorological models are often evaluated and optimized on the basis of micrometeorological measurements. However, it has been known for more than three decades that surface measurements of sensible and latent heat energy (LE) are systematically underestimated. We studied this problem using six years of eddy-correlation measurements for four fields (corn, soybean, and prairie) in central Iowa, USA. We recorded major components of the energy equation (i.e. net radiation, sensible heat flux, LE, and soil heat flux, photosynthesis), and indirectly estimated most of the minor components of energy balance (namely storage in the soil, canopy and air). Storage in the canopy was related to leaf area index (LAI) acquired from Moderate Resolution Imaging Spectrometer (MODIS). In this paper, a diagnostic approach is investigated where systematic error is identified first. Three dimensional (3D) plots of the residual of energy equation vs. potential variables indicated the imbalance was largest mainly during the cold non-growing season when the soil was dry. Correlations between energy balance residual (EBR) and energy components showed that soil storage was not precisely estimated. Finally, an a-posteriori analysis (constrained linear multiple regression (CMLR)) was conducted to quantify the contribution of major/minor components of the energy equation towards EBR. The result highlights that the contribution of pertinent components of energy to EBR is mainly controlled by prevailing monthly hydrometeorological conditions;however, precise quantification of causes of imbalance is site-specific. A comparison between the a-posteriori analysis technique and the Bowen-ratio method demonstrates that the Bowen-ratio basically presumes a higher level of underestimation in LE. The results obtained in this study suggest that a-posteriori analysis may offer a superior methodology to correct measured eddy-correlation measurements. Furthermore, the overall trends in the correction of LE measurements suggest that there is a potential for rough monthly corrections of LE, irrespective of the type of crop.
文摘In this study we explore a method which provides an insight into the effectiveness of various hydrologic models’ routing components based on their ability to accurately represent flood peak times and shapes. The method is based on using Cross-Wavelet Transforms to estimate the phase (time) difference between the time series of the observed and the simulated discharges. In this article we evaluate two routing components, the Routing Application for Parallel Computation of Discharge (RAPID), which is based on the simplified Muskingum routing method, and the routing component of the non-linear Hillslope-Link hydrologic Model (HLM) produced in the Iowa Flood Center (IFC). Both routing components are driven by the same source of runoff and used the same channel network to ensure that the discrepancies between the simulated stream discharges are due to channel routing alone. We also explore the suitability of different wavelet shapes for our application, and how the difference in wavelet shape can affect our evaluation results. Unlike the conventional statistical skill scores used to evaluate model performance (e.g. Root Mean Squared Error, correlation coefficient, and Nash Sutcliff efficiency index), which give an estimate of the overall hydrograph performance, our method conveniently provides time-localized information with higher resolution at peak location. We perform our evaluation at multiple stream gauge locations, covering a wide range of scales (700 to 16,862 km2), located in the eastern part of the state of Iowa. Our results show that the proposed wavelet method is effective in evaluating the performance of the routing components in simulating peak times across spatial scales. Generally, the non-linear routing method employed in the HLM outperformed the Muskingum based method employed in RAPID. In addition, our results suggest that the Paul wavelet is more effective in detecting and separating individual peaks than the Morlet wavelet, which in turn leads to a more accurate evaluation of the routing components.
文摘Western Ghats region of India is one of the biodiversity hotspots of the world. The topography, wide rainfall variation and varied temperature conditions enable inhabitancy of several plant species. This plant wealth is being used in various forms by tribes and natives of the area for centuries. These gain further importance due to the fact that ripe fruits serve as a source of food and medicine to tribes throughout the year. These wild fruits are source of minerals and vitamins in the diet of the rural people. The potential productivity and floristic diversity of the area have attracted the experts. There are more than 50 wild edible fruit species are available in Western Ghats region. These belong to 25 families and 38 genera. Out of the 25 families, the important ones as a source of fruits are Apocynaceae, Anacardiaceae, Euphorbiaceae, Moraceae, Sapotaceae and Sapindaceae. The fruiting period of different species ranges between two and six months. The highest number of species mature from April to May. The availability of these fruits reduces after October. Some of these fruits, such as Mangifera indica, Artocarpus heterophyllus, Carissa carandas, Emblica officinalis and Syzygium cuminii, have been given emphasis in order to identify high yield and high fruit quality clones and standardization of production technologies. The collection, conservation and utilization on some of the fruits, such as Garcinia indica and Garcinia gummigutta have started at various research organizations. Some other fruits, namely Chrysophyllum roxburghii （Family Sapotaceae）, Canthium parviflora Lamk syn. Plectronia parviflora （Lam.） Bedd. （Family Rubiaceae）, Elaeagnus conferta Roxbsyn, Elaeagnus latifolia L. （Family Elaeagnaceae）, Securina leucopyrus syn. Flueggea leucopyrus （Family Euphorbiaceae）, Elaeocarpus tuberculatus Roxb. （Family Elaeocarpaceae）, Nephelium stipulacum Bedd. syn. Doratoxylon stipulatum （Family Sapindaceae） have potential for commercial cultivation. Thus, attempts were made with the objective of recording availability of these species, proximate analysis and their on farm and off farm conservation at Central Horticultural Experiment Station （CHES）. Few plants were also provided to local growers on farm conservation. The continuous depletion of forest and the increasing human disturbance resulted in losses of these species. There is need to conserve these fruits for future.
基金supported by the National Science Foundation (NSF) [grant numbers CBET-1703796,CBET-1702610,CBET-1335711,CHE-1609791]the National Institute of Environmental Health Sciences/National Institute of Health [grant number P30 ES005605].
文摘Benoxacor is a safener added to current-use herbicide formulations to protect the target crop from herbicidal toxicity.It is an emerging environmental contaminant that has been detected in surface waters,raising the possibility of human exposure via drinking water.Because it is not subject to the same regulations as active pesticide ingredients,its metabolism and toxicity in humans have not been studied.Here we investigate the enantioselective metabolism of benoxacor in human subcellular fractions.Pooled human liver microsomes(pHLM)and cytosol(pHLC)were incubated with racemic benoxacor for up to 30-min.Gas chromatographic analyses were used to measure the enantioselective depletion of benoxacor.pHLMs with and without nicotinamide adenine dinucleotide phosphate(NADPH,co-factor for cytochrome P450 enzymes[CYPs])and pHLC with glutathione(GSH,co-factor for glutathione Stransferases[GSTs])metabolized benoxacor.These results demonstrate that microsomal CYPs,microsomal carboxylesterase(CESs),and cytosolic GSTs metabolize benoxacor.Females were predicted to have a higher clearance of benoxacor by GSTs than males.Male and female pHLM incubations with NADPH showed enrichment of the first eluting benoxacor enantiomer(E1-benoxacor).pHLM incubations without NADPH and pHLC incubations with GSH showed an enrichment of the second eluting enantiomer of benoxacor(E2-benoxacor).Our results indicate that human hepatic microsomal and cytosolic enzymes enantioselectively metabolize benoxacor,a fact that needs to be considered when investigating human exposures and toxicities of benoxacor.
