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Sample records for lolium multiflorum populations

  1. Genome instability in Novel Lolium multiflorum x L. arundinaceum hybrids

    USDA-ARS?s Scientific Manuscript database

    We have identified a method whereby Lolium multiflorum (Lm) or L. arundinaceum (Fa) genomes are preferentially eliminated through a mitotic loss behavior in interspecific Lm x Fa F1 hybrids,generating either dihaploid Lm lines or Fa lines. The genome instability has been visualized phenotypically an...

  2. EPSPS gene amplification in glyphosate-resistant in Italian ryegrass (Lolium perenne ssp. multiflorum) populations from Arkansas, USA

    USDA-ARS?s Scientific Manuscript database

    Glyphosate-resistant Italian ryegrass was detected in Arkansas, USA in 2007. In 2014, 45 populations were confirmed resistant in eight counties across the state. The level of resistance and resistance mechanisms in six populations was studied to assess the severity of the problem and identify altern...

  3. EPSPS Gene Amplification in Glyphosate-Resistant Italian Ryegrass (Lolium perenne ssp. multiflorum) Populations from Arkansas (United States).

    PubMed

    Salas, Reiofeli A; Scott, Robert C; Dayan, Franck E; Burgos, Nilda R

    2015-07-01

    Glyphosate-resistant Italian ryegrass was detected in Arkansas (United States) in 2007. In 2014, 45 populations were confirmed resistant in eight counties across the state. The level of resistance and resistance mechanisms in six populations were studied to assess the severity of the problem and identify alternative management approaches. Dose-response bioassays, glyphosate absorption and translocation experiments, herbicide target (EPSPS) gene sequence analysis, and gene amplification assays were conducted. The dose causing 50% growth reduction (GR50) was 7-19 times higher for the resistant population than for the susceptible standard. Uptake and translocation of (14)C-glyphosate were similar in resistant and susceptible plants, and no mutation in the EPSPS gene known to be associated with resistance to glyphosate was detected. Resistant plants contained from 11- to >100-fold more copies of the EPSPS gene than the susceptible plants, whereas the susceptible plants had only one copy of EPSPS. Plants surviving the recommended dose of glyphosate contained at least 10 copies. The EPSPS copy number was positively related to glyphosate resistance level (r = 80). Therefore, resistance to glyphosate in these populations is due to multiplication of the target site. Resistance mechanisms could be location-specific. Suppressing the mechanism for gene amplification may overcome resistance.

  4. An aspartate to glycine change in the carboxyl transferase domain of acetyl CoA carboxylase and non-target-site mechanism(s) confer resistance to ACCase inhibitor herbicides in a Lolium multiflorum population.

    PubMed

    Kaundun, Shiv Shankhar

    2010-11-01

    The increasing use of ACCase-inhibiting herbicides has resulted in evolved resistance in key grass weeds infesting cereal cropping systems worldwide. Here, a thorough and systematic approach is proposed to elucidate the basis of resistance to three ACCase herbicides in a Lolium multiflorum Lam. (Italian rye grass) population from the United Kingdom (UK24). Resistance to sethoxydim and pinoxaden was always associated with a dominant D2078G (Alopecurus myosuroides Huds. equivalent) target-site mutation in UK24. Conversely, whole-plant herbicide assays on predetermined ACCase genotypes showed very high levels of resistance to diclofop-methyl for all three wild DD2078 and mutant DG2078 and GG2078 ACCase genotypes from the mixed resistant population UK24. This indicates the presence of other diclofop-methyl-specific resistance mechanism(s) yet to be determined in this population. The D2078G mutation could be detected using an unambiguous DNA-based dCAPS procedure that proved very transferable to A. myosuroides, Avena fatua L., Setaria viridis (L.) Beauv. and Phalaris minor Retz. This study provides further understanding of the molecular basis of resistance to ACCase inhibitor herbicides in a Lolium population and a widely applicable PCR-based method for monitoring the D2078G target-site resistance mutation in five major grass weed species. Copyright © 2010 Society of Chemical Industry.

  5. Multiple Herbicide Resistance in Lolium multiflorum and Identification of Conserved Regulatory Elements of Herbicide Resistance Genes

    PubMed Central

    Mahmood, Khalid; Mathiassen, Solvejg K.; Kristensen, Michael; Kudsk, Per

    2016-01-01

    Herbicide resistance is a ubiquitous challenge to herbicide sustainability and a looming threat to control weeds in crops. Recently four genes were found constituently over-expressed in herbicide resistant individuals of Lolium rigidum, a close relative of Lolium multiflorum. These include two cytochrome P450s, one nitronate monooxygenase and one glycosyl-transferase. Higher expressions of these four herbicide metabolism related (HMR) genes were also observed after herbicides exposure in the gene expression databases, indicating them as reliable markers. In order to get an overview of herbicidal resistance status of L. multiflorum L, 19 field populations were collected. Among these populations, four populations were found to be resistant to acetolactate synthase (ALS) inhibitors while three exhibited resistance to acetyl-CoA carboxylase (ACCase) inhibitors in our initial screening and dose response study. The genotyping showed the presence of mutations Trp-574-Leu and Ile-2041-Asn in ALS and ACCase, respectively, and qPCR experiments revealed the enhanced expression of HMR genes in individuals of certain resistant populations. Moreover, co-expression networks and promoter analyses of HMR genes in O. sativa and A. thaliana resulted in the identification of a cis-regulatory motif and zinc finger transcription factors. The identified transcription factors were highly expressed similar to HMR genes in response to xenobiotics whereas the identified motif is known to play a vital role in coping with environmental stresses and maintaining genome stability. Overall, our findings provide an important step forward toward a better understanding of metabolism-based herbicide resistance that can be utilized to devise novel strategies of weed management. PMID:27547209

  6. A Novel W1999S Mutation and Non-Target Site Resistance Impact on Acetyl-CoA Carboxylase Inhibiting Herbicides to Varying Degrees in a UK Lolium multiflorum Population

    PubMed Central

    Kaundun, Shiv Shankhar; Bailly, Geraldine C.; Dale, Richard P.; Hutchings, Sarah-Jane; McIndoe, Eddie

    2013-01-01

    Background Acetyl-CoA carboxylase (ACCase) inhibiting herbicides are important products for the post-emergence control of grass weed species in small grain cereal crops. However, the appearance of resistance to ACCase herbicides over time has resulted in limited options for effective weed control of key species such as Lolium spp. In this study, we have used an integrated biological and molecular biology approach to investigate the mechanism of resistance to ACCase herbicides in a Lolium multiflorum Lam. from the UK (UK21). Methodology/Principal Findings The study revealed a novel tryptophan to serine mutation at ACCase codon position 1999 impacting on ACCase inhibiting herbicides to varying degrees. The W1999S mutation confers dominant resistance to pinoxaden and partially recessive resistance to cycloxydim and sethoxydim. On the other hand, plants containing the W1999S mutation were sensitive to clethodim and tepraloxydim. Additionally population UK21 is characterised by other resistance mechanisms, very likely non non-target site based, affecting several aryloxyphenoxyproprionate (FOP) herbicides but not the practical field rate of pinoxaden. The positive identification of wild type tryptophan and mutant serine alleles at ACCase position 1999 could be readily achieved with an original DNA based derived cleaved amplified polymorphic sequence (dCAPS) assay that uses the same PCR product but two different enzymes for positively identifying the wild type tryptophan and mutant serine alleles identified here. Conclusion/Significance This paper highlights intrinsic differences between ACCase inhibiting herbicides that could be exploited for controlling ryegrass populations such as UK21 characterised by compound-specific target site and non-target site resistance. PMID:23469130

  7. QTL analysis of lodging resistance and related traits in Italian ryegrass ( Lolium multiflorum Lam.).

    PubMed

    Inoue, Maiko; Gao, Zhensheng; Cai, Hongwei

    2004-11-01

    Italian ryegrass ( Lolium multiflorum Lam.) is the most widely cultivated annual forage grass in Japan. Lodging damage reduces both harvested yield and forage quality. To identify the chromosomal regions controlling lodging resistance in Italian ryegrass, we analyzed seven quantitative characters--heading date, plant height, culm weight, culm diameter, culm strength, tiller number, and culm pushing resistance--and evaluated lodging scores in the field in a two-way pseudo-testcross F1 population. Significant correlations between most combinations of the traits examined were found. Seventeen QTLs for all traits except culm weight were detected on six of seven linkage groups by simple interval mapping using cross-pollination (CP) algorithm, and 33 independent QTLs were also detected by composite interval mapping from both male and female parental linkage maps. In addition, up to 18 QTLs for lodging scores evaluated at nine different times were detected on all linkage groups. The flanking markers of those QTLs will serve as a useful tool for marker-assisted selection of lodging resistance in Italian ryegrass.

  8. Vacuolar Sequestration of Paraquat Is Involved in the Resistance Mechanism in Lolium perenne L. spp. multiflorum

    PubMed Central

    Brunharo, Caio A. C. G.; Hanson, Bradley D.

    2017-01-01

    Lolium perenne L. spp. multiflorum (Lam.) Husnot (LOLMU) is a winter annual weed, common to row crops, orchards and roadsides. Glyphosate-resistant populations of LOLMU are widespread in California. In many situations, growers have switched to paraquat or other postemergence herbicides to manage glyphosate-resistant LOLMU populations. Recently, poor control of LOLMU with paraquat was reported in a prune orchard in California where paraquat has been used several times. We hypothesize that the low efficacy observed is due to the selection of a paraquat-resistant biotype of LOLMU. Greenhouse dose-response experiments conducted with a susceptible (S) and the putative paraquat-resistant biotype (PRHC) confirmed paraquat resistance in PRHC. Herbicide absorption studies indicated that paraquat is absorbed faster in S than PRHC, although the maximum absorption estimates were similar for the two biotypes. Conversely, translocation of 14C-paraquat under light-manipulated conditions was restricted to the treated leaf of PRHC, whereas herbicide translocation out of the treated leaf was nearly 20 times greater in S. To determine whether paraquat was active within the plant cells, the photosynthetic performance was assessed after paraquat application using the parameter maximum quantum yield of photosystem II (Fv/Fm). Paraquat reaches the chloroplasts of PRHC, since there was a transitory inhibition of photosynthetic activity in PRHC leaves. However, PRHC Fv/Fm recovered to initial levels by 48 h after paraquat treatment. No paraquat metabolites were found, indicating that resistance is not due to paraquat degradation. LOLMU leaf segments were exposed to paraquat following pretreatments with inhibitors of plasma membrane- and tonoplast-localized transporter systems to selectively block paraquat intracellular movement. Subsequent evaluation of membrane integrity indicated that pre-exposure to putrescine resulted in the resistant biotype responding to paraquat similarly to S

  9. Utilization of flow cytometry to identify chimeral sectors in leaf tissue of Lolium multiflorum x L. arundinaceum hybrids

    USDA-ARS?s Scientific Manuscript database

    We have identified a method whereby Lolium multiflorum (Lm) or L. arundinaceum (Fa) genomes are preferentially eliminated through a mitotic loss behavior in interspecific Lm x Fa F1 hybrids, generating either dihaploid Lm lines or Fa lines. Flow cytometry, a method for rapidly characterizing optical...

  10. Italian ryegrass (Lolium multiflorum) and corn (Zea mays)competition

    USDA-ARS?s Scientific Manuscript database

    Italian ryegrass is an annual/biennial grass that is typically used as a pasture crop or a cover crop along roadsides, rights-of-way, and industrial areas. Glyphosate-resistant (GR) Italian ryegrass populations have been documented around the world, mostly in orchard and vineyard situations. The fir...

  11. Consistent detection of QTLs for crown rust resistance in Italian ryegrass (Lolium multiflorum Lam.) across environments and phenotyping methods.

    PubMed

    Studer, Bruno; Boller, Beat; Bauer, Eva; Posselt, Ulrich K; Widmer, Franco; Kölliker, Roland

    2007-06-01

    Crown rust, caused by Puccinia coronata f. sp. lolii, is one of the most important diseases of temperate forage grasses, such as ryegrasses (Lolium spp.), affecting yield and nutritional quality. Therefore, resistance to crown rust is a major goal in ryegrass breeding programmes. In a two-way pseudo-testcross population consisting of 306 Lolium multiflorum individuals, multisite field evaluations as well as alternative methods based on artificial inoculation with natural inoculate in controlled environments were used to identify QTLs controlling resistance to crown rust. Disease scores obtained from glasshouse and leaf segment test (LST) evaluations were highly correlated with scores from a multisite field assessment (r = 0.66 and 0.79, P < 0.01, respectively) and thus confirmed suitability of these methods for crown rust investigations. Moreover, QTL mapping based on a linkage map consisting of 368 amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers revealed similar results across different phenotyping methods. Two major QTLs were consistently detected on linkage group (LG) 1 and LG 2, explaining up to 56% of total phenotypic variance (V (p)). Nevertheless, differences between position and magnitude of QTLs were observed among individual field locations and suggested the existence of specific local pathogen populations. The present study not only compared QTL results among crown rust evaluation methods and environments, but also identified molecular markers closely linked to previously undescribed QTLs for crown rust resistance in Italian ryegrass with the potential to be applied in marker-assisted forage crop breeding.

  12. Facilitation of a native pest of rice, Stenotus rubrovittatus (Hemiptera: Miridae), by the non-native Lolium multiflorum (Cyperales: Poaceae) in an agricultural landscape.

    PubMed

    Yoshioka, Akira; Takada, Mayura; Washitani, Izumi

    2011-10-01

    Source populations of polyphagous pests often occur on host plants other than the economically damaged crop. We evaluated the contribution of patches of a non-native meadow grass, Lolium multiflorum Lam. (Poaceae), and other weeds growing in fallow fields or meadows as source hosts of an important native pest of rice, Stenotus rubrovittatus (Matsumura) (Hemiptera: Miridae), in an agricultural landscape of northern Japan. Periodical censuses of this mirid bug by using the sweeping method, vegetation surveys, and statistical analysis revealed that L. multiflorum was the only plant species that was positively correlated with the density of adult S. rubrovittatus through two generations and thus may be the most stable and important host of the mirid bug early in the season before the colonization of rice paddies. The risk and cost of such an indirect negative effect on a crop plant through facilitation of a native pest by a non-native plant in the agricultural landscape should not be overlooked.

  13. Enhancement of nitrogen and phosphorus removal from eutrophic water by economic plant annual ryegrass (Lolium multiflorum) with ion implantation.

    PubMed

    Li, Miao; Sheng, Guo-ping; Wu, Yue-jin; Yu, Zeng-liang; Bañuelos, Gary S; Yu, Han-qing

    2014-01-01

    Severe eutrophication of surface water has been a major problem of increasing environmental concern worldwide. In the present study, economic plant annual ryegrass (Lolium multiflorum) was grown in floating mats as an economic plant-based treatment system to evaluate its potential after ion implantation for removing nutrients in simulated eutrophic water. The specific weight growth rate of L. multiflorum with ion implantation was significantly greater than that of the control, and the peroxidase, nitrate reductase, and acid phosphatase activities of the irradiated L. multiflorum were found to be greater than those plants without ion implantation. Higher total nitrogen (TN) and total phosphorus (TP) removal efficiencies were obtained for the L. multiflorum irradiated with 25 keV 5.2 × 10(16) N(+) ions/cm(2) and 30 keV 4.16 × 10(16) N(+) ions/cm(2), respectively (p < 0.05). Furthermore, the nitrogen and phosphorus contents in the plant biomass with ion implantation were also greater than those in the control and were positively correlated with TN and TP supplied. L. multiflorum itself was directly responsible for 39-49 and 47-58 % of the overall N and P removal in the experiment, respectively. The research results suggested that ion implantation could become a promising approach for increasing phytoremediation efficiency of nutrients from eutrophic water by L. multiflorum.

  14. Metabolism or behavior: explaining the performance of aphids on alkaloid-producing fungal endophytes in annual ryegrass (Lolium multiflorum).

    PubMed

    Bastias, Daniel A; Ueno, Andrea C; Machado Assefh, Cristina R; Alvarez, Adriana E; Young, Carolyn A; Gundel, Pedro E

    2017-09-06

    Plant-herbivore interactions are often mediated by plant microorganisms, and the "defensive mutualism" of epichloid fungal endophytes of grasses is an example. These endophytes synthesize bioactive alkaloids that generally have detrimental effects on the performance of insect herbivores, but the underlying mechanisms are not well understood. Our objective was to determine whether changes in the physiology and/or behavior of aphids explain the changes in performance of insects feeding on endophytic plants. We studied the interaction between the aphid Rhopalosiphum padi and the annual ryegrass Lolium multiflorum symbiotic (E+) or not symbiotic (E-) with the fungus Epichloë occultans that can synthesize loline alkaloids. We hypothesized that aphids feeding on E+ plants have higher energetic demands for detoxification of fungal alkaloids, thereby negatively impacting the individual performance, population growth, and structure. Aphids growing on E+ plants had lower values in morphometric and functional variables of individual performance, displayed lower birth rate, smaller population size, and dramatic structural changes. However, aphids exhibited lower values of standard metabolic rate (SMR) on E+ plants, which suggests no high costs of detoxification. Behavioral variables during the first 8 h of feeding showed that aphids did not change the phloem sap ingestion with the presence of fungal endophytes. We hypothesize that aphids may maintain phloem sap ingestion according to their fungal alkaloid tolerance capacity. In other words, when alkaloid concentrations overcome tolerance threshold, ingestion of phloem should decrease, which may explain the observed lower values of SMR in E+ feeding aphids.

  15. Effect of D2O on growth properties and chemical structure of annual ryegrass (Lolium multiflorum)

    SciTech Connect

    Evans, Barbara R; Bali, Garima; Reeves, David T; O'Neill, Hugh Michael; Sun, Qining; Shah, Riddhi S; Ragauskas, Arthur

    2014-01-01

    In present paper, we report the production and detailed structural analysis of deuterium-enriched rye grass (Lolium multiflorum) for neutron scattering experiments. An efficient method to produce deuterated biomass was developed by designing hydroponic perfusion chambers. In preliminary studies, the partial deuterated rye samples were grown in increasing levels of D2O to study the seed germination and the level of deuterium incorporation as a function of D2O concentration. Solution NMR method indicated 36.9 % deuterium incorporation in 50 % D2O grown annual rye samples and further significant increase in the deuterium incorporation level was observed by germinating the rye seedlings in H2O and growing in 50 % D2O inside the perfusion chambers. Moreover, in an effort to compare the substrate characteristics related to enzymatic hydrolysis on deuterated and protiated version of biomass, annual rye grown in 50 % D2O was selected for detailed biomass characterization studies. The compositional analyses, degree of polymerization and cellulose crystallinity were compared with its protiated control. The cellulose molecular weight indicated slight variation with deuteration; however, hemicellulose molecular weights and cellulose crystallinity remain unaffected with the deuteration. Besides the minor differences in biomass components, the development of deuterated biomass for neutron scattering application is essential to understand the complex biomass conversion processes.

  16. Comparative “Golgi” Proteome Study of Lolium multiflorum and Populus trichocarpa

    PubMed Central

    Ford, Kristina L.; Chin, Tony; Srivastava, Vaibhav; Zeng, Wei; Doblin, Monika S.; Bulone, Vincent; Bacic, Antony

    2016-01-01

    The Golgi apparatus (GA) is a crucial organelle in the biosynthesis of non-cellulosic polysaccharides, glycoproteins and proteoglycans that are primarily destined for secretion to the cell surface (plasma membrane, cell wall and apoplast). Only a small proportion of the proteins involved in these processes have been identified in plants, with the majority of their functions still unknown. The availability of a GA proteome would greatly assist plant biochemists, cell and molecular biologists in determining the precise function of the cell wall-related proteins. There has been some progress towards defining the GA proteome in the model plant system Arabidopsis thaliana, yet in commercially important species, such as either the cereals or woody species there has been relatively less progress. In this study, we applied discontinuous sucrose gradient centrifugation to partially enrich GA from suspension cell cultures (SCCs) and combined this with stable isotope labelling (iTRAQ) to determine protein sub-cellular locations. Results from a representative grass species, Italian ryegrass (Lolium multiflorum) and a dicot species, black cottonwood (Populus trichocarpa) are compared. The results confirm that membrane fractionation approaches that provide effective GA-enriched fractions for proteomic analyses in Arabidopsis are much less effective in the species examined here and highlight the complexity of the GA, both within and between species. PMID:28248233

  17. Comparative proteomic analyses reveal the proteome response to short-term drought in Italian ryegrass (Lolium multiflorum).

    PubMed

    Pan, Ling; Yang, Zhongfu; Wang, Jianping; Wang, Pengxi; Ma, Xiao; Zhou, Meiliang; Li, Ji; Gang, Nie; Feng, Guangyan; Zhao, Junming; Zhang, Xinquan

    2017-01-01

    Drought is a major abiotic stress that impairs growth and productivity of Italian ryegrass. Comparative analysis of drought responsive proteins will provide insight into molecular mechanism in Lolium multiflorum drought tolerance. Using the iTRAQ-based approach, proteomic changes in tolerant and susceptible lines were examined in response to drought condition. A total of 950 differentially accumulated proteins was found to be involved in carbohydrate metabolism, amino acid metabolism, biosynthesis of secondary metabolites, and signal transduction pathway, such as β-D-xylosidase, β-D-glucan glucohydrolase, glycerate dehydrogenase, Cobalamin-independent methionine synthase, glutamine synthetase 1a, Farnesyl pyrophosphate synthase, diacylglycerol, and inositol 1, 4, 5-trisphosphate, which might contributed to enhance drought tolerance or adaption in Lolium multiflorum. Interestingly, the two specific metabolic pathways, arachidonic acid and inositol phosphate metabolism including differentially accumulated proteins, were observed only in the tolerant lines. Cysteine protease cathepsin B, Cysteine proteinase, lipid transfer protein and Aquaporin were observed as drought-regulated proteins participating in hydrolysis and transmembrane transport. The activities of phospholipid hydroperoxide glutathione peroxidase, peroxiredoxin, dehydroascorbate reductase, peroxisomal ascorbate peroxidase and monodehydroascorbate reductase associated with alleviating the accumulation of reactive oxygen species in stress inducing environments. Our results showed that drought-responsive proteins were closely related to metabolic processes including signal transduction, antioxidant defenses, hydrolysis, and transmembrane transport.

  18. Influence of tea saponin on enhancing accessibility of pyrene and cadmium phytoremediated with Lolium multiflorum in co-contaminated soils.

    PubMed

    Wang, Qian; Liu, Xiaoyan; Zhang, Xinying; Hou, Yunyun; Hu, Xiaoxin; Liang, Xia; Chen, Xueping

    2016-03-01

    Tea saponin (TS), a kind of biodegradable surfactant, was chosen to improve the accessible solubilization of pyrene and cadmium (Cd) in co-contaminated soils cultivated Lolium multiflorum. TS obviously improved the accessibility of pyrene and Cd for L. multiflorum to accelerate the process of accumulation and elimination of the pollutants. The chemical forms of Cd was transformed from Fe-Mn oxides and associated to carbonates fractions into exchangeable fractions by adding TS in single Cd and pyrene-Cd contaminated soils. Moreover, the chemical forms of pyrene were transformed from associated fraction into bioaccessible fraction by adding TS in pyrene and pyrene-Cd contaminated soils. In pyrene-Cd contaminated soil, the exchangeable fraction of Cd was hindered in the existence of pyrene, and bioaccessible fraction of pyrene was promoted by the cadmium. Besides, in the process of the pyrene degradation and Cd accumulation, the effect could be improved by the elongation of roots with adding TS, and the microorganism activity was stimulated by TS to accelerate the removal of pollutions. Therefore, Planting L. multiflorum combined with adding TS would be an effective method on the phytoremediation of organics and heavy metals co-contaminated soils.

  19. Short-term changes of fructans in ryegrass (Lolium multiflorum 'Lema') in response to urban air pollutants and meteorological conditions.

    PubMed

    Sandrin, Carla Zuliani; Figueiredo-Ribeiro, Rita de Cássia Leone; Delitti, Welington Braz Carvalho; Domingos, Marisa

    2013-10-01

    We investigated whether the fructan content, a storage carbohydrate, of Lolium multiflorum 'Lema' plants grown in a subtropical urban environment characterized by typical diurnal profiles of air pollutants and meteorological conditions changed over the course of a day during different seasons. Plants were collected every 2h on the last day of each two-month seasonal field experiment and separated into shoot (stubble or stubble+leaf blades) and roots for carbohydrate analyses and biomass determination. Diurnal contents of total fructose in the stubbles increased with high temperatures. In the roots, fructose accumulation showed a positive relation with hourly variations of both temperature and particulate matter and a negative relation with irradiance and SO2. Seasonal variation in shoot and root biomasses coincided with the seasonal variation of total fructose and were negatively affected by relative humidity and SO2, respectively. We concluded that hourly changes of fructans over the course of a day may increase the ability of L. multiflorum to tolerate short-term oscillations in weather and air pollution commonly observed in the subtropical urban environment, increasing its efficiency in monitoring air quality.

  20. Integrated assessment of air pollution by metals and source apportionment using ryegrass (Lolium multiflorum Lam.) in southern Brazil.

    PubMed

    Illi, Júlia Carolina; Vancetta, Tafael; Alves, Darlan Daniel; Osório, Daniela Montanari Migliavacca; Bianchin, Liane; de Quevedo, Daniela Müller; Juchem, Fernando

    2017-01-01

    One of the biggest environmental problems existing today is air pollution, which is characterized by the presence of toxic gases and metal pollutants, the latter of which is generally associated with emissions of particulate matter (PM) from industries or automotive vehicles. Biomonitoring is a method that can be used to assess air pollution levels because it makes it possible to determine what effects these air pollutants cause in living organisms and their responses. The species Lolium multiflorum Lam., known as ryegrass, is considered a good bioindicator of metals, since it accumulates these substances during exposure. This study proposes to conduct an integrated assessment of air quality using two different monitoring methodologies: biomonitoring with L. multiflorum and active monitoring in areas with different levels of urbanization and industrialization. Concentrations found in ryegrass plants revealed high levels of Pb, Cr, Zn, and Cu, indicating that vehicular and industrial emissions were the main sources of pollution. Analysis of PM also revealed soot and biogenic particles, which can transport metals. Therefore, with the proposed method, the anthropogenic impact on air pollution in the investigated area could be clearly demonstrated.

  1. Transcriptional Profiles of Drought-Related Genes in Modulating Metabolic Processes and Antioxidant Defenses in Lolium multiflorum

    PubMed Central

    Pan, Ling; Zhang, Xinquan; Wang, Jianping; Ma, Xiao; Zhou, Meiliang; Huang, LinKai; Nie, Gang; Wang, Pengxi; Yang, Zhongfu; Li, Ji

    2016-01-01

    Drought is a major environmental stress that limits growth and development of cool-season annual grasses. Drought transcriptional profiles of resistant and susceptible lines were studied to understand the molecular mechanisms of drought tolerance in annual ryegrass (Lolium multiflorum L.). A total of 4718 genes exhibited significantly differential expression in two L. multiflorum lines. Additionally, up-regulated genes associated with drought response in the resistant lines were compared with susceptible lines. Gene ontology enrichment and pathway analyses revealed that genes partially encoding drought-responsive proteins as key regulators were significantly involved in carbon metabolism, lipid metabolism, and signal transduction. Comparable gene expression was used to identify the genes that contribute to the high drought tolerance in resistant lines of annual ryegrass. Moreover, we proposed the hypothesis that short-term drought have a beneficial effect on oxidation stress, which may be ascribed to a direct effect on the drought tolerance of annual ryegrass. Evidence suggests that some of the genes encoding antioxidants (HPTs, GGT, AP, 6-PGD, and G6PDH) function as antioxidant in lipid metabolism and signal transduction pathways, which have indispensable and promoting roles in drought resistance. This study provides the first transcriptome data on the induction of drought-related gene expression in annual ryegrass, especially via modulation of metabolic homeostasis, signal transduction, and antioxidant defenses to improve drought tolerance response to short-term drought stress. PMID:27200005

  2. Development of EST-derived CAPS and AFLP markers linked to a gene for resistance to ryegrass blast (Pyricularia sp.) in Italian ryegrass (Lolium multiflorum Lam.).

    PubMed

    Miura, Yuichi; Ding, Chenglong; Ozaki, Rie; Hirata, Mariko; Fujimori, Masahiro; Takahashi, Wataru; Cai, Hongwei; Mizuno, Kazuhiko

    2005-09-01

    Ryegrass blast, also called gray leaf spot, is caused by the fungus Pyricularia sp. It is one of the most serious diseases of Italian ryegrass (Lolium multiflorum Lam.) in Japan. We analyzed segregation of resistance in an F(1) population from a cross between a resistant and a susceptible cultivar. The disease severity distribution in the F(1) population suggested that resistance was controlled by a major gene (Lm Pi1). Analysis of amplified fragment length polymorphisms with bulked segregant analysis identified several markers tightly linked to Lm Pi1. To identify other markers linked to Lm Pi1, we used expressed sequence tag-cleaved amplified polymorphic sequence (EST-CAPS) markers mapped in a reference population of Italian ryegrass. Of the 30 EST-CAPS markers screened, one marker, p 56, flanking the Lm Pi1 locus was found. The restriction pattern of p 56 amplification showed a unique fragment corresponding to the resistant allele at the Lm Pi1 locus. A linkage map constructed from the reference population showed that the Lm Pi1 locus was located in linkage group 5 of Italian ryegrass. Genotype results obtained from resistant and susceptible cultivars indicate that the p 56 marker is useful for introduction of the Lm Pi1 gene into susceptible germ plasm in order to develop ryegrass cultivars with enhanced resistance to ryegrass blast.

  3. Effects of different fertilizers on growth and nutrient uptake of Lolium multiflorum grown in Cd-contaminated soils.

    PubMed

    Liu, Mohan; Li, Yang; Che, Yeye; Deng, Shaojun; Xiao, Yan

    2017-08-25

    This study aimed to explore the effects of different fertilizers and their combinations on growth and nutrient and Cd uptake of Lolium multiflorum. Compared with control treatment, chemical fertilizer, organic manure, and their conjunctions with biofertilizer increased shoot biomass. Biofertilizers were found to cause significant reductions in shoot biomass of plants grown in organic manure-treated and control soil. Decreased soil-available N and P and shoot N and K concentrations in biofertilizer amendment treatments indicated that plant growth and nutrient absorption might be negatively affected under nutrient deficiency conditions. Elevated shoot biomasses contributed to the highest shoot Cd contents in chemical fertilizer and chemical fertilizer + biofertilizer treatments among all treatments. But the maximum translocation efficiency occurred in biofertilizer + chemical fertilizer + organic manure treatment, followed by organic manure and chemical fertilizer + organic manure treatments. Based on the results, we can conclude that the application of only the biofertilizer Bacillus subtilis should be avoided in nutrient-limited soils. Chemical fertilizer application could benefit the amount of Cd in shoots, and organic manure application and its combinations could result in the higher translocation efficiency.

  4. Chemical Composition, In vivo Digestibility and Metabolizable Energy Values of Caramba (Lolium multiflorum cv. caramba) Fresh, Silage and Hay.

    PubMed

    Özelçam, H; Kırkpınar, F; Tan, K

    2015-10-01

    The experiment was conducted to determine nutritive values of caramba (Lolium multiflorum cv. caramba) fresh, silage and hay by in vivo and in vitro methods. There was a statistically significant difference (p<0.01) in crude protein content value between fresh caramba (12.83%) and silage (8.91%) and hay (6.35%). According to results of experiment, the crude fiber, neutral detergent fiber, acid detergent fiber (ADF), acid detergent lignin contents of the three forms of caramba varied between 30.22% to 35.06%, 57.41% to 63.70%, 35.32% to 43.29%, and 5.55% to 8.86% respectively. There were no significant differences between the three forms of caramba in digestibility of nutrients and in vivo metabolizable energy (ME) values (p>0.05). However, the highest MECN (ME was estimated using crude nutrients) and MEADF values were found in fresh caramba (p<0.01). As a result, it could be said that, there were no differences between the three forms of caramba in nutrient composition, digestibility and ME value, besides drying and ensiling did not affect digestibility of hay. Consequently, caramba either as fresh, silage or hay is a good alternative source of forage for ruminants.

  5. Chemical Composition, In vivo Digestibility and Metabolizable Energy Values of Caramba (Lolium multiflorum cv. caramba) Fresh, Silage and Hay

    PubMed Central

    Özelçam, H.; Kırkpınar, F.; Tan, K.

    2015-01-01

    The experiment was conducted to determine nutritive values of caramba (Lolium multiflorum cv. caramba) fresh, silage and hay by in vivo and in vitro methods. There was a statistically significant difference (p<0.01) in crude protein content value between fresh caramba (12.83%) and silage (8.91%) and hay (6.35%). According to results of experiment, the crude fiber, neutral detergent fiber, acid detergent fiber (ADF), acid detergent lignin contents of the three forms of caramba varied between 30.22% to 35.06%, 57.41% to 63.70%, 35.32% to 43.29%, and 5.55% to 8.86% respectively. There were no significant differences between the three forms of caramba in digestibility of nutrients and in vivo metabolizable energy (ME) values (p>0.05). However, the highest MECN (ME was estimated using crude nutrients) and MEADF values were found in fresh caramba (p<0.01). As a result, it could be said that, there were no differences between the three forms of caramba in nutrient composition, digestibility and ME value, besides drying and ensiling did not affect digestibility of hay. Consequently, caramba either as fresh, silage or hay is a good alternative source of forage for ruminants. PMID:26323399

  6. Antioxidant, anti-inflammatory and anti-septic potential of phenolic acids and flavonoid fractions isolated from Lolium multiflorum.

    PubMed

    Choi, Ki-Choon; Son, Young-Ok; Hwang, Jung-Min; Kim, Beom-Tae; Chae, Minseon; Lee, Jeong-Chae

    2017-12-01

    Interest has recently renewed in using Lolium multiflorum Lam. (Poaceae) (called Italian ryegrass; IRG) silage as an antioxidant and anti-inflammatory diet. This study investigated the antioxidant, anti-inflammatory and anti-septic potential of IRG silage and identified the primary components in IRG active fractions. Total 16 fractions were separated from the chloroform-soluble extract of IRG aerial part using Sephadex LH-20 column before HPLC analysis. Antioxidant and anti-inflammatory activities of the fractions at doses of 0-100 μg/mL were investigated using various cell-free and cell-mediated assay systems. To explore anti-septic effect of IRG fractions, female ICR and BALB/c mice orally received 40 mg/kg of phenolic acid and flavonoid-rich active fractions F7 and F8 every other day for 10 days, respectively, followed by LPS challenge. The active fractions showed greater antioxidant and anti-inflammatory potential compared with other fractions. IC50 values of F7 and F8 to reduce LPS-stimulated NO and TNF-α production were around 15 and 30 μg/mL, respectively. Comparison of retention times with authentic compounds through HPLC analysis revealed the presence of caffeic acid, ferulic acid, myricetin and kaempferol in the fractions as primary components. These fractions inhibited LPS-stimulated MAPK and NF-κB activation. Supplementation with F7 or F8 improved the survival rates of mice to 70 and 60%, respectively, in LPS-injected mice and reduced near completely serum TNF-α and IL-6 levels. This study highlights antioxidant, anti-inflammatory and anti-septic activities of IRG active fractions, eventually suggesting their usefulness in preventing oxidative damage and inflammatory disorders.

  7. Transpiration flow controls Zn transport in Brassica napus and Lolium multiflorum under toxic levels as evidenced from isotopic fractionation

    NASA Astrophysics Data System (ADS)

    Couder, Eléonore; Mattielli, Nadine; Drouet, Thomas; Smolders, Erik; Delvaux, Bruno; Iserentant, Anne; Meeus, Coralie; Maerschalk, Claude; Opfergelt, Sophie; Houben, David

    2015-11-01

    Stable zinc (Zn) isotope fractionation between soil and plant has been used to suggest the mechanisms affecting Zn uptake under toxic conditions. Here, changes in Zn isotope composition in soil, soil solution, root and shoot were studied for ryegrass (Lolium multiflorum L.) and rape (Brassica napus L.) grown on three distinct metal-contaminated soils collected near Zn smelters (total Zn 0.7-7.5%, pH 4.8-7.3). The Zn concentrations in plants reflected a toxic Zn supply. The Zn isotopic fingerprint of total soil Zn varied from -0.05‰ to +0.26 ± 0.02‰ (δ66Zn values relative to the JMC 3-0749L standard) among soils, but the soil solution Zn was depleted in 66Zn, with a constant Zn isotope fractionation of about -0.1‰ δ66Zn unit compared to the bulk soil. Roots were enriched with 66Zn relative to soil solution (δ66Znroot - δ66Znsoil solution = Δ66Znroot-soil solution = +0.05 to +0.2 ‰) and shoots were strongly depleted in 66Zn relative to roots (Δ66Znshoot-root = -0.40 to -0.04 ‰). The overall δ66Zn values in shoots reflected that of the bulk soil, but were lowered by 0.1-0.3 ‰ units as compared to the latter. The isotope fractionation between root and shoot exhibited a markedly strong negative correlation (R2 = 0.83) with transpiration per unit of plant weight. Thus, the enrichment with light Zn isotopes in shoot progressed with increasing water flux per unit plant biomass dry weight, showing a passive mode of Zn transport by transpiration. Besides, the light isotope enrichment in shoots compared to roots was larger for rape than for rye grass, which may be related to the higher Zn retention in rape roots. This in turn may be related to the higher cation exchange capacity of rape roots. Our finding can be of use to trace the biogeochemical cycles of Zn and evidence the tolerance strategies developed by plants in Zn-excess conditions.

  8. Treatment of an acid soil with bentonite used for wine fining: effects on soil properties and the growth of Lolium multiflorum.

    PubMed

    Arias-Estévez, Manuel; López-Periago, Eugenio; Nóvoa-Muñoz, Juan C; Torrado-Agrasar, Ana; Simal-Gándara, Jesus

    2007-09-05

    When used to fine wines, bentonite acquires a protein load that makes it a potentially useful fertilizer. Other properties of bentonite are also potentially useful for soil amendment. In the work described in this paper, waste bentonite from a winery was applied to an acid soil, and its effects on soil properties and on the growth of Lolium multiflorum were evaluated. Soil N, K, and P contents all increased, as did pH and cation exchange capacity. Biomass production increased as the dose of bentonite increased up to 5 g kg(-1), decreasing at larger doses (possibly as a result of falling potassium/magnesium ratio and increasing electrical conductivity). Environmental drawbacks of waste bentonite include its high soluble copper content, although its conversion in the soil to less soluble forms reduces its potential phytotoxicity. The copper, manganese, and zinc contents of the ryegrass crop were low.

  9. In Vitro and In Vivo Enhancement of Adipogenesis by Italian Ryegrass (Lolium multiflorum) in 3T3-L1 Cells and Mice

    PubMed Central

    Kim, Da Hye; Gun Roh, Sang; Lee, Jeong-Chae; Choi, Ki Choon

    2014-01-01

    Adipogenesis is very much important in improving the quality of meat in animals. The aim of the present study was to investigate the in vitro and in vivo adipogenesis regulation properties of Lolium multiflorum on 3T3-L1 pre-adipocytes and mice. Chemical composition of petroleum ether extract of L. multiflorum (PET-LM) confirmed the presence of fatty acids, such as α-linolenic acid, docosahexaenoic acid, oleic acid, docosatetraenoic acid, and caprylic acid, as the major compounds. PET-LM treatment increased viability, lipid accumulation, lipolysis, cell cycle progression, and DNA synthesis in the cells. PET-LM treatment also augmented peroxysome proliferator activated receptor (PPAR)-γ2, CCAAT/enhancer binding protein-α, adiponectin, adipocyte binding protein, glucose transporter-4, fatty acid synthase, and sterol regulatory element binding protein-1 expression at mRNA and protein levels in differentiated adipocytes. In addition, mice administered with 200 mg/kg body weight PET-LM for 8 weeks showed greater body weight than control mice. These findings suggest that PET-LM facilitates adipogenesis by stimulating PPARγ-mediated signaling cascades in adipocytes which could be useful for quality meat development in animals. PMID:24454838

  10. In-vitro assessment of the probiotic potential of Lactobacillus plantarum KCC-24 isolated from Italian rye-grass (Lolium multiflorum) forage.

    PubMed

    Vijayakumar, Mayakrishnan; Ilavenil, Soundharrajan; Kim, Da Hye; Arasu, Mariadhas Valan; Priya, Kannappan; Choi, Ki Choon

    2015-04-01

    The aim of the present study was to determine the probiotic potential of the lactic acid bacteria Lactobacillus plantarum KCC-24 (L. plantarum KCC-24), that was isolated and characterized from Italian ryegrass (Lolium multiflorum) forage. The following experiments were performed to assess the probiotic characteristics such as antifungal activity, antibiotic susceptibility, resistance to low pH, stimulated gastric juice and bile salts, proteolytic activity, auto-aggregation, cell surface hydrophobicity, and in vitro antioxidant property. The isolated L. plantarum KCC-24 exhibited significant antifungal activity against the various fungal strains of Aspergillus fumigatus (73.43%), Penicillium chrysogenum (59.04%), Penicillium roqueforti (56.67%), Botrytis elliptica (40.23%), Fusarium oxysporum (52.47%) and it was susceptible to numerous antibiotics, survived in low pH, was resistant to stimulated gastric juices and bile salts (0.3% w/v). Moreover, L. plantarum KCC-24 exhibited good proteolytic activity. In addition L. plantarum KCC-24 showed potent antioxidant and hydrogen peroxide resistant property. In conclusion, the isolated L. plantarum KCC-24 exhibited several characteristics to prove it's excellent as a potential probiotic candidate for developing quality food for ruminant animals and human.

  11. Phylogenetic and functional diversity of alkane degrading bacteria associated with Italian ryegrass (Lolium multiflorum) and Birdsfoot trefoil (Lotus corniculatus) in a petroleum oil-contaminated environment.

    PubMed

    Yousaf, Sohail; Andria, Verania; Reichenauer, Thomas G; Smalla, Kornelia; Sessitsch, Angela

    2010-12-15

    Twenty-six different plant species were analyzed regarding their performance in soil contaminated with petroleum oil. Two well-performing species, Italian ryegrass (Lolium multiflorum var. Taurus), Birdsfoot trefoil (Lotus corniculatus var. Leo) and the combination of these two plants were selected to study the ecology of plant-associated, culturable alkane-degrading bacteria. Hydrocarbon degrading bacteria were isolated from the rhizosphere, root interior and shoot interior and subjected to the analysis of 16S rRNA gene, the 16S and 23S rRNA intergenic spacer region and alkane hydroxylase genes. Furthermore, we investigated whether alkane hydroxylase genes are plasmid located. Higher numbers of culturable, alkane-degrading bacteria were associated with Italian ryegrass, which were also characterized by a higher diversity, particularly in the plant interior. Only half of the isolated bacteria hosted known alkane hydroxylase genes (alkB and cytochrome P153-like). Degradation genes were found both on plasmids as well as in the chromosome. In regard to application of plants for rhizodegradation, where support of numerous degrading bacteria is essential for efficient break-down of pollutants, Italian ryegrass seems to be more appropriate than Birdsfoot trefoil.

  12. Phosphorus status and microbial community of paddy soil with the growth of annual ryegrass (Lolium multiflorum Lam.) under different phosphorus fertilizer treatments*

    PubMed Central

    Guo, Hai-chao; Wang, Guang-huo

    2009-01-01

    Annual ryegrass (Lolium multiflorum Lam.) was grown in paddy soil in pots under different phosphorus (P) fertilizer treatments to investigate changes of P fractions and microbial community of the soil. The treatments included Kunyang phosphate rock (KPR) applications at 50 mg P/kg (KPR50) and 250 mg P/kg (KPR250), mono-calcium phosphate (MCP) application at 50 mg P/kg (MCP50), and the control without P application. The results showed that KPR50, KPR250, and MCP50 applications significantly increased the dry weight of the ryegrass by 13%, 38%, and 55%, and increased P uptake by 19%, 135%, and 324%, respectively. Compared with MCP50, the relative effectiveness of KPR50 and KPR250 treatments in ryegrass production was about 23% and 68%, respectively. After one season of ryegrass growth, the KPR50, KPR250, and MCP50 applications increased soil-available P by 13.4%, 26.8%, and 55.2%, respectively. More than 80% of the applied KPR-P remained as HCl-P fraction in the soil. Phospholipid fatty acid (PLFA) analysis showed that the total and bacterial PLFAs were significantly higher in the soils with KPR250 and MCP50 treatments compared with KPR50 and control. The latter had no significant difference in the total or bacterial PLFAs. The KPR50, KPR250, and MCP50 treatments increased fungal PLFA by 69%, 103%, and 69%, respectively. Both the principal component analysis and the cluster analysis of the PLFA data suggest that P treatments altered the microbial community composition of the soils, and that P availability might be an important contributor to the changes in the microbial community structure during the ryegrass growth in the paddy soils. PMID:19817001

  13. Evaluation of the grass mixture (Faestuca Rubra, Cynodon Dactylon, Lolium Multiflorum and Pennisetum sp.) as Sb phyto-stabilizer in tailings and Sb-rich soils.

    NASA Astrophysics Data System (ADS)

    Aurora Armienta, M.; Beltrán-Villavicencio, Margarita; Ruiz-Villalobos, Carlos E.; Labastida, Israel; Ceniceros, Nora; Cruz, Olivia; Aguayo, Alejandra

    2017-04-01

    Green house experiments were carried out to evaluate the growth and Sb assimilation of a grass assemblage: Faestuca Rubra, Cynodon Dactylon, Lolium Multiflorum and Pennisetum sp, in tailings and Sb-rich soils. Tailings and soil samples were obtained at the Mexican historical mining zone of Zimapán, Central México. More than 6 tailings impoundments are located at the town outskirts and constitute a contamination source from windblown and waterborne deposit on soils, besides acid mine drainage. Four substrates were used in the experiments: 100% tailings, 20% tailings + 80% soil, 50% tailings + 50% soil , and a soil sample far from tailings as a background. Concentrations of Sb ranged from 310 mg/kg to 413 mg/kg in tailings. A pH of 7.43, 1.27% organic matter, and high concentrations of N, K and P indicated adequate conditions for plant growth. The grass assemblage was raised during 21 days as indicated by OECD (Organisation for Economic Co-operation and Development) Guideline 208 Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test. The highest Sb concentrations were measured in plants grown on tailings with 139 mg/kg in the aerial part and 883 mg/kg in roots. Concentrations of Sb decreased as the proportion of tailings diminished with 22.1 mg/kg in the aerial part and 10 mg/kg in roots corresponding to the plants grown in the 20 % tailings + 80% soil . Bioaccumulation (BAC) and bioconcentration factors (BF) of plants grown on tailings (BAC= 0.42, BCF=3.93) indicated their suitability as a phyto-stabilization option. The grass mixture may be thus applied to control windblown particulate tailings taking advantage to their tolerance to high Sb levels.

  14. Water Deficit Affects Primary Metabolism Differently in Two Lolium multiflorum/Festuca arundinacea Introgression Forms with a Distinct Capacity for Photosynthesis and Membrane Regeneration.

    PubMed

    Perlikowski, Dawid; Czyżniejewski, Mariusz; Marczak, Łukasz; Augustyniak, Adam; Kosmala, Arkadiusz

    2016-01-01

    Understanding how plants respond to drought at different levels of cell metabolism is an important aspect of research on the mechanisms involved in stress tolerance. Furthermore, a dissection of drought tolerance into its crucial components by the use of plant introgression forms facilitates to analyze this trait more deeply. The important components of plant drought tolerance are the capacity for photosynthesis under drought conditions, and the ability of cellular membrane regeneration after stress cessation. Two closely related introgression forms of Lolium multiflorum/Festuca arundinacea, differing in the level of photosynthetic capacity during stress, and in the ability to regenerate their cellular membranes after stress cessation, were used as forage grass models in a primary metabolome profiling and in an evaluation of chloroplast 1,6-bisphosphate aldolase accumulation level and activity, during 11 days of water deficit, followed by 10 days of rehydration. It was revealed here that the introgression form, characterized by the ability to regenerate membranes after rehydration, contained higher amounts of proline, melibiose, galactaric acid, myo-inositol and myo-inositol-1-phosphate involved in osmoprotection and stress signaling under drought. Moreover, during the rehydration period, this form also maintained elevated accumulation levels of most the primary metabolites, analyzed here. The other introgression form, characterized by the higher capacity for photosynthesis, revealed a higher accumulation level and activity of chloroplast aldolase under drought conditions, and higher accumulation levels of most photosynthetic products during control and drought periods. The potential impact of the observed metabolic alterations on cellular membrane recovery after stress cessation, and on a photosynthetic capacity under drought conditions in grasses, are discussed.

  15. Water Deficit Affects Primary Metabolism Differently in Two Lolium multiflorum/Festuca arundinacea Introgression Forms with a Distinct Capacity for Photosynthesis and Membrane Regeneration

    PubMed Central

    Perlikowski, Dawid; Czyżniejewski, Mariusz; Marczak, Łukasz; Augustyniak, Adam; Kosmala, Arkadiusz

    2016-01-01

    Understanding how plants respond to drought at different levels of cell metabolism is an important aspect of research on the mechanisms involved in stress tolerance. Furthermore, a dissection of drought tolerance into its crucial components by the use of plant introgression forms facilitates to analyze this trait more deeply. The important components of plant drought tolerance are the capacity for photosynthesis under drought conditions, and the ability of cellular membrane regeneration after stress cessation. Two closely related introgression forms of Lolium multiflorum/Festuca arundinacea, differing in the level of photosynthetic capacity during stress, and in the ability to regenerate their cellular membranes after stress cessation, were used as forage grass models in a primary metabolome profiling and in an evaluation of chloroplast 1,6-bisphosphate aldolase accumulation level and activity, during 11 days of water deficit, followed by 10 days of rehydration. It was revealed here that the introgression form, characterized by the ability to regenerate membranes after rehydration, contained higher amounts of proline, melibiose, galactaric acid, myo-inositol and myo-inositol-1-phosphate involved in osmoprotection and stress signaling under drought. Moreover, during the rehydration period, this form also maintained elevated accumulation levels of most the primary metabolites, analyzed here. The other introgression form, characterized by the higher capacity for photosynthesis, revealed a higher accumulation level and activity of chloroplast aldolase under drought conditions, and higher accumulation levels of most photosynthetic products during control and drought periods. The potential impact of the observed metabolic alterations on cellular membrane recovery after stress cessation, and on a photosynthetic capacity under drought conditions in grasses, are discussed. PMID:27504113

  16. Finishing steers on winter annual ryegrass (Lolium multiflorum Lam.) with varied levels of corn supplementation I: effects on animal performance, carcass traits, and forage quality.

    PubMed

    Roberts, S D; Kerth, C R; Braden, K W; Rankins, D L; Kriese-Anderson, L; Prevatt, J W

    2009-08-01

    Crossbred steers (n = 72) were selected to study forage-based finishing systems using winter annual ryegrass (Lolium multiflorum Lam.) with varying levels of grain supplementation. In December, cattle were allotted to 1 of 6 treatments consisting of ryegrass pasture (1 ha) with whole shell corn supplemented at 0.0% (0.0), 0.5% (0.5), 1.0% (1.0), 1.5% (1.5), and 2.0% (2.0) of BW, or an ad libitum mixed-ration grain diet in a drylot. Steers were randomly assigned to pens of 4 with pen serving as the experimental unit. Cattle were slaughtered by pen when average pen backfat thickness (as measured by real-time ultrasound) reached approximately 0.64 cm. Forage samples and disk meter height were taken from ryegrass paddocks on a monthly basis to determine forage quality and mass. Live animal performance, carcass traits, proximate analysis, Warner-Bratzler shear force, and sensory characteristics from the LM of the rib section were analyzed. Increasing the amount of grain in the diet of finishing cattle resulted in a linear decrease (P < 0.05) in days on feed and a linear increase (P < 0.05) in ADG, preliminary yield grade, final yield grade, flavor intensity, and beef flavor. Forage DM mass increased with each incremental increase in grain added to the grazing diets. Quality of forage was not (P > 0.05) affected by adding grain to the diet. Adding corn to the diet of cattle being finished on forage improved animal performance and decreased forage utilization characteristics in addition to improving the flavor characteristics of beef.

  17. ESPS gene amplification endows resistance to glyphosate in Italian ryegrass (Lolium perene ssp multiflorum) from Arkansas, USA

    USDA-ARS?s Scientific Manuscript database

    Resistance to glyphosate in weed species is a major challenge for the sustainability of glyphosate use in crop and non-crop systems, and especially in glyphosate-resistant crops. A glyphosate-resistant Italian ryegrass population has been identified in Arkansas. This research was conducted to elucid...

  18. Influence of short-term drought conditions and subsequent re-watering on the physiology and proteome of Lolium multiflorum/Festuca arundinacea introgression forms, with contrasting levels of tolerance to long-term drought.

    PubMed

    Perlikowski, D; Kosmala, A; Rapacz, M; Kościelniak, J; Pawłowicz, I; Zwierzykowski, Z

    2014-03-01

    Festuca arundinacea is a drought tolerant species. Lolium multiflorum has better forage quality but lower tolerance to abiotic stresses. Their hybrids offer an opportunity to perform research on the molecular basis of tolerance to drought. The aim of this work was to recognise the mechanisms of response to short-term drought (11 days) in a glasshouse in two L. multiflorum/F. arundinacea introgression forms with distinct levels of tolerance to long-term drought (14 weeks) in the field. Measurements of physiological parameters, analyses of protein accumulation profiles using two-dimensional gel electrophoresis, and mass spectrometry identification of proteins, which were accumulated differentially between the selected genotypes during short-term drought, were performed. Genotype 7/6, with lower yield potential during 14 weeks of drought, and lower ability to re-grow after watering, had a higher capacity for photosynthesis during 11 days of drought. Genotype 4/10, more tolerant to long-term drought, was able to repair damaged cell membranes after watering and was also characterised by lower transpiration during short-term drought. A total of 455 proteins were analysed, and the 17 that were differentially accumulated between the two genotypes were identified. The results of physiological and proteomic research led to a hypothesis that the higher photosynthetic capacity of genotype 7/6 could be due to a more efficient Calvin cycle, supported by higher accumulation of crucial proteins involving chloroplast aldolase. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. Implementation of Genomic Prediction in Lolium perenne (L.) Breeding Populations

    PubMed Central

    Grinberg, Nastasiya F.; Lovatt, Alan; Hegarty, Matt; Lovatt, Andi; Skøt, Kirsten P.; Kelly, Rhys; Blackmore, Tina; Thorogood, Danny; King, Ross D.; Armstead, Ian; Powell, Wayne; Skøt, Leif

    2016-01-01

    Perennial ryegrass (Lolium perenne L.) is one of the most widely grown forage grasses in temperate agriculture. In order to maintain and increase its usage as forage in livestock agriculture, there is a continued need for improvement in biomass yield, quality, disease resistance, and seed yield. Genetic gain for traits such as biomass yield has been relatively modest. This has been attributed to its long breeding cycle, and the necessity to use population based breeding methods. Thanks to recent advances in genotyping techniques there is increasing interest in genomic selection from which genomically estimated breeding values are derived. In this paper we compare the classical RRBLUP model with state-of-the-art machine learning techniques that should yield themselves easily to use in GS and demonstrate their application to predicting quantitative traits in a breeding population of L. perenne. Prediction accuracies varied from 0 to 0.59 depending on trait, prediction model and composition of the training population. The BLUP model produced the highest prediction accuracies for most traits and training populations. Forage quality traits had the highest accuracies compared to yield related traits. There appeared to be no clear pattern to the effect of the training population composition on the prediction accuracies. The heritability of the forage quality traits was generally higher than for the yield related traits, and could partly explain the difference in accuracy. Some population structure was evident in the breeding populations, and probably contributed to the varying effects of training population on the predictions. The average linkage disequilibrium between adjacent markers ranged from 0.121 to 0.215. Higher marker density and larger training population closely related with the test population are likely to improve the prediction accuracy. PMID:26904088

  20. Development of simple sequence repeat (SSR) markers and construction of an SSR-based linkage map in Italian ryegrass (Lolium multiflorum Lam.).

    PubMed

    Hirata, Mariko; Cai, Hongwei; Inoue, Maiko; Yuyama, Nana; Miura, Yuichi; Komatsu, Toshinori; Takamizo, Tadashi; Fujimori, Masahiro

    2006-07-01

    In order to develop simple sequence repeat (SSR) markers in Italian ryegrass, we constructed a genomic library enriched for (CA)n-containing SSR repeats. A total of 1,544 clones were sequenced, of which 1,044 (67.6%) contained SSR motifs, and 395 unique clones were chosen for primer design. Three hundred and fifty-seven of these clones amplified products of the expected size in both parents of a two-way pseudo-testcross F(1) mapping population, and 260 primer pairs detected genetic polymorphism in the F(1) population. Genetic loci detected by a total of 218 primer pairs were assigned to locations on seven linkage groups, representing the seven chromosomes of the haploid Italian ryegrass karyotype. The SSR markers covered 887.8 cM of the female map and 795.8 cM of the male map. The average distance between two flanking SSR markers was 3.2 cM. The SSR markers developed in this study will be useful in cultivar discrimination, linkage analysis, and marker-assisted selection of Italian ryegrass and closely related species.

  1. Mechanisms of glyphosate resistance in two perennial ryegrass (Lolium perenne) populations.

    PubMed

    Ghanizadeh, Hossein; Harrington, Kerry C; James, Trevor K; Woolley, David J; Ellison, Nicholas W

    2015-12-01

    Perennial ryegrass (Lolium perenne) has developed resistance to glyphosate within New Zealand vineyards following many years of herbicide application. The objectives of this work were to confirm resistance within two populations obtained from affected vineyards, and to determine the mechanism of resistance to glyphosate. Population O was confirmed to have a 25-fold resistance to glyphosate, whereas population J had a sevenfold resistance. Results of genotyping assays demonstrated a single nucleotide substitution at codon 106 of 5-enolpyruvylshikimate-3-phosphate synthase in population O but not population J. Glyphosate-resistant and glyphosate-susceptible populations did not differ in glyphosate absorption. However, in both resistant populations, much more of the absorbed (14) C-glyphosate remained in the treated leaf than occurred in the susceptible population. Significantly more glyphosate was found in the pseudostem region of susceptible plants compared with resistant plants. Both target-site and non-target-site mechanisms of glyphosate resistance were found in the perennial ryegrass population with 25-fold resistance, whereas only the non-target-site mechanism of resistance was found in the population with sevenfold resistance. This is the first study of the mechanism of glyphosate resistance in perennial ryegrass. © 2014 Society of Chemical Industry.

  2. Untargeted Metabotyping Lolium perenne Reveals Population-Level Variation in Plant Flavonoids and Alkaloids

    PubMed Central

    Cao, Mingshu; Fraser, Karl; Jones, Chris; Stewart, Alan; Lyons, Thomas; Faville, Marty; Barrett, Brent

    2017-01-01

    Metabolomics provides a powerful platform to characterize plants at the biochemical level, allowing a search for underlying genes and associations with higher level complex traits such as yield and nutritional value. Efficient and reliable methods to characterize metabolic variation in economically important species are considered of high value to the evaluation and prioritization of germplasm and breeding lines. In this investigation, a large-scale metabolomic survey was performed on a collection of diverse perennial ryegrass (Lolium perenne L.) plants. A total of 2,708 data files, derived from liquid chromatography coupled to high resolution mass spectrometry (LCMS), were selected to assess the effectiveness and efficiency of applying high throughput metabolomics to survey chemical diversity in plant populations. The data set was generated from 23 ryegrass populations, with 3–25 genotypes per population, and five clonal replicates per genotype. We demonstrate an integrated approach to rapidly mine and analyze metabolic variation from this large, multi-batch LCMS data set. After performing quality control, statistical data mining and peak annotation, a wide range of variation for flavonoid glycosides and plant alkaloids was discovered among the populations. Structural variation of flavonoids occurs both in aglycone structures and acetylated/malonylated/feruloylated sugar moieties. The discovery of comprehensive metabolic variation among the plant populations offers opportunities to probe into the genetic basis of the variation, and provides a valuable resource to gain insight into biochemical functions and to relate metabolic variation with higher level traits in the species. PMID:28223996

  3. Widespread occurrence of both metabolic and target-site herbicide resistance mechanisms in Lolium rigidum populations.

    PubMed

    Han, Heping; Yu, Qin; Owen, Mechelle J; Cawthray, Gregory R; Powles, Stephen B

    2016-02-01

    Lolium rigidum populations in Australia and globally have demonstrated rapid and widespread evolution of resistance to acetyl coenzyme A carboxylase (ACCase)-inhibiting and acetolactate synthase (ALS)-inhibiting herbicides. Thirty-three resistant L. rigidum populations, randomly collected from crop fields in a most recent resistance survey, were analysed for non-target-site diclofop metabolism and all known target-site ACCase gene resistance-endowing mutations. The HPLC profile of [(14) C]-diclofop-methyl in vivo metabolism revealed that 79% of these resistant L. rigidum populations showed enhanced capacity for diclofop acid metabolism (metabolic resistance). ACCase gene sequencing identified that 91% of the populations contain plants with ACCase resistance mutation(s). Importantly, 70% of the populations exhibit both non-target-site metabolic resistance and target-site ACCase mutations. This work demonstrates that metabolic herbicide resistance is commonly occurring in L. rigidum, and coevolution of both metabolic resistance and target-site resistance is an evolutionary reality. Metabolic herbicide resistance can potentially endow resistance to many herbicides and poses a threat to herbicide sustainability and thus crop production, calling for major research and management efforts. © 2015 Society of Chemical Industry.

  4. Evolution of glyphosate resistance in a Lolium rigidum population by glyphosate selection at sublethal doses.

    PubMed

    Busi, R; Powles, S B

    2009-10-01

    The majority of the documented cases of field-evolved herbicide-resistant weed biotypes established that single major genes confer glyphosate resistance. However, the contribution of minor genes endowing substantial plant survival at sublethal herbicide doses may be a potential complementary path to herbicide resistance evolution in weed populations under selection. Here, we subjected a number of susceptible individuals of Lolium rigidum to recurrent glyphosate selection to test the potential for sublethal glyphosate doses to additively select for glyphosate resistance. After 3-4 cycles of glyphosate selection in two distinct environments, the progenies of the initially susceptible population were shifted toward glyphosate resistance. The results indicate progressive enrichment of minor gene trait(s) contributing toward plant survival in the glyphosate-selected progenies. After three generations of selection, the estimated LD(50) values were doubled compared with the original population and up to 33% plant survival was obtained in the glyphosate-selected progeny at the recommended glyphosate label rate. This level of resistance probably was the maximum shift achievable with sublethal glyphosate dose selection in this small population. Cross-pollination was a crucial factor enabling the rapid rate of accumulation of minor glyphosate resistance gene trait(s) that are likely to be present at a relatively high frequency in a small susceptible population. The mechanistic basis of the moderate glyphosate resistance level selected by sublethal glyphosate doses remains unknown and warrants future research. Studying the main factors influencing the evolution of resistant weed populations is crucial for understanding, predicting and managing herbicide resistance.

  5. New report of Lolium multiflorum and Rumex crispus as weed hosts of epiphytic populations of Psuedomonas sp., causal agent of yellow bud in onion in Geogia, USA

    USDA-ARS?s Scientific Manuscript database

    Yellow bud, an emerging bacterial disease of onion (Allium cepa L.), has been spreading throughout the Vidalia onion-growing region in Georgia since 2007. Symptoms of yellow bud include intense chlorosis in emerging leaves and severe blight in the older leaves leading to stand loss and reduced bulb ...

  6. Survey and Detection of Endophytic Fungi in Lolium Germ Plasm by Direct Staining and Aphid Assays

    Treesearch

    A. Dan Wilson; Stephen L. Clement; Walter J. Kaiser

    1991-01-01

    Clavicipitaceous anamorphic endophytes were detected in 28 of 85 accessions from five of eight species in a collection of Lolium germ plasm. Comparative descriptions of endophytic mycelium in seeds of L. multiflorum, L. perenne, L. persicum, L. rigidum, and L. temulentum revealed morphological characteristics...

  7. QTL for resistance in Lolium perenne to a mixed population of Puccinia graminis subsp. graminicola: use of RAD (restriction site associated DNA) markers to rapidly populate a new linkage map

    USDA-ARS?s Scientific Manuscript database

    A mapping population was created to detect quantitative trait loci (QTL) for resistance to stem rust caused by Puccinia graminis subsp. graminicola in Lolium perenne. Susceptible and resistant plants were crossed to produce a pseudo-testcross population. Markers were produced by the Restriction-sit...

  8. Plastome Sequence Determination and Comparative Analysis for Members of the Lolium-Festuca Grass Species Complex

    PubMed Central

    Hand, Melanie L.; Spangenberg, German C.; Forster, John W.; Cogan, Noel O. I.

    2013-01-01

    Chloroplast genome sequences are of broad significance in plant biology, due to frequent use in molecular phylogenetics, comparative genomics, population genetics, and genetic modification studies. The present study used a second-generation sequencing approach to determine and assemble the plastid genomes (plastomes) of four representatives from the agriculturally important Lolium-Festuca species complex of pasture grasses (Lolium multiflorum, Festuca pratensis, Festuca altissima, and Festuca ovina). Total cellular DNA was extracted from either roots or leaves, was sequenced, and the output was filtered for plastome-related reads. A comparison between sources revealed fewer plastome-related reads from root-derived template but an increase in incidental bacterium-derived sequences. Plastome assembly and annotation indicated high levels of sequence identity and a conserved organization and gene content between species. However, frequent deletions within the F. ovina plastome appeared to contribute to a smaller plastid genome size. Comparative analysis with complete plastome sequences from other members of the Poaceae confirmed conservation of most grass-specific features. Detailed analysis of the rbcL–psaI intergenic region, however, revealed a “hot-spot” of variation characterized by independent deletion events. The evolutionary implications of this observation are discussed. The complete plastome sequences are anticipated to provide the basis for potential organelle-specific genetic modification of pasture grasses. PMID:23550121

  9. Four QTLs determine crown rust (Puccinia coronata f. sp. lolii) resistance in a perennial ryegrass (Lolium perenne) population.

    PubMed

    Muylle, H; Baert, J; Van Bockstaele, E; Pertijs, J; Roldán-Ruiz, I

    2005-11-01

    Crown rust resistance is an important selection criterion in ryegrass breeding. The disease, caused by the biotrophic fungus Puccinia coronata, causes yield losses and reduced quality. In this study, we used linkage mapping and QTL analysis to unravel the genomic organization of crown rust resistance in a Lolium perenne population. The progeny of a pair cross between a susceptible and a resistant plant were analysed for crown rust resistance. A linkage map, consisting of 227 loci (AFLP, SSR, RFLP and STS) and spanning 744 cM, was generated using the two-way pseudo-testcross approach from 252 individuals. QTL analysis revealed four genomic regions involved in crown rust resistance. Two QTLs were located on LG1 (LpPc4 and LpPc2) and two on LG2 (LpPc3 and LpPc1). They explain 12.5, 24.9, 5.5 and 2.6% of phenotypic variance, respectively. An STS marker, showing homology to R genes, maps in the proximity of LpPc2. Further research is, however, necessary to check the presence of functional R genes in this region. Synteny at the QTL level between homologous groups of chromosomes within the Gramineae was observed. LG1 and LG2 show homology with group A and B chromosomes of oat on which crown rust-resistance genes have been identified, and with the group 1 chromosomes of the Triticeae, on which leaf rust-resistance genes have been mapped. These results are of major importance for understanding the molecular background of crown rust resistance in ryegrasses. The identified markers linked to crown rust resistance have the potential for use in marker-assisted breeding.

  10. Biodegradation of phenanthrene, spatial distribution of bacterial populations and dioxygenase expression in the mycorrhizosphere of Lolium perenne inoculated with Glomus mosseae.

    PubMed

    Corgié, S C; Fons, F; Beguiristain, T; Leyval, C

    2006-05-01

    Interactions between the plant and its microbial communities in the rhizosphere control microbial polycyclic aromatic hydrocarbons (PAH) biodegradation processes. Arbuscular mycorrhizal (AM) fungi can influence plant survival and PAH degradation in polluted soil. This work was aimed at studying the contribution of the mycorrhizosphere to PAH biodegradation in the presence of ryegrass (Lolium perenne L., cv. Barclay) inoculated with Glomus mosseae (BEG 69) by taking into account the structure and activity of bacterial communities, PAH degrading culturable bacteria as a function of the distance from roots. Ryegrass was grown in compartmentalized systems designed to harvest successive sections of rhizosphere in lateral compartments polluted or not with phenanthrene (PHE). Colonization of roots by G. mosseae (BEG 69) modified the structure and density of bacterial populations in the mycorrhizosphere, compared to the rhizosphere of non-mycorrhizal plants. G. mosseae increased the density of culturable heterotrophic and PAH degrading bacteria beyond the immediate rhizosphere in the presence of PHE, and increased the density of PAH degraders in the absence of the pollutant. Biodegradation was not significantly increased in the mycorrhizosphere, compared to control non-mycorrhizal plants, where PHE biodegradation already reached 92% after 6 weeks. However, dioxygenase transcriptional activity was found to be higher in the immediate mycorrhizosphere in the presence of G. mosseae (BEG 69).

  11. Forward selection for multiple resistance across the non-selective glyphosate, glufosinate and oxyfluorfen herbicides in Lolium weed species.

    PubMed

    Fernández, Pablo; Alcántara, Ricardo; Osuna, María D; Vila-Aiub, Martin M; Prado, Rafael De

    2017-05-01

    In the Mediterranean area, Lolium species have evolved resistance to glyphosate after decades of continual use without other alternative chemicals in perennial crops (olive, citrus and vineyards). In recent years, oxyfluorfen alone or mixed with glyphosate and glufosinate has been introduced as a chemical option to control dicot and grass weeds. Dose-response studies confirmed that three glyphosate-resistant Lolium weed species (L. rigidum, L. perenne, L. multiflorum) collected from perennial crops in the Iberian Peninsula have also evolved resistance to glufosinate and oxyfluorfen herbicides, despite their recent introduction. Based on the LD50 resistance parameter, the resistance factor was similar among Lolium species and ranged from 14- to 21-fold and from ten- to 12-fold for oxyfluorfen and glufosinate respectively. Similarly, about 14-fold resistance to both oxyfluorfen and glufosinate was estimated on average for the three Lolium species when growth reduction (GR50 ) was assessed. This study identified oxyfluorfen resistance in a grass species for the first time. A major threat to sustainability of perennial crops in the Iberian Peninsula is evident, as multiple resistance to non-selective glyphosate, glufosinate and oxyfluorfen herbicides has evolved in L. rigidum, L. perenne and L. multiflorum weeds. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  12. Contrasting genetic structure between Magnaporthe grisea populations associated with the golf course turfgrasses Lolium perenne (perennial ryegrass) and Pennisetum clandestinum (kikuyugrass).

    PubMed

    Douhan, Greg W; de la Cerda, Karla A; Huryn, Karyn L; Greer, Christopher A; Wong, Francis P

    2011-01-01

    Gray leaf spot (GLS) disease of perennial ryegrass (Lolium perenne) and kikuyugrass (Pennisetum clandestinum) in golf courses in California was first noted in 2001 and 2003, respectively, and within 5 years had become well established. The causal agent of the disease is the fungus Magnaporthe grisea, which is known to consist primarily of clonal lineages that are highly host specific. Therefore, our objective was to investigate host specificity and population dynamics among isolates associated primarily from perennial ryegrass and kikuyugrass since the disease emerged at similar times in California. We also obtained isolates from additional hosts (tall fescue, St. Augustinegrass, weeping lovegrass, and rice) and from the eastern United States for comparative purposes. A total of 38 polymorphic amplified fragment length polymorphism makers were scored from 450 isolates which clustered by host with high bootstrap support (71 to 100%). Genetic structure between kikuyugrass and perennial ryegrass isolates differed significantly. Isolates from kikuyugrass were genotypically diverse (n = 34), possessed both mating types, and some tests for random mating could not be rejected, whereas isolates from perennial ryegrass were less genotypically diverse (n = 10) and only consisted of a single mating type. Low genotypic diversity was also found among the other host specific isolates which also only consisted of a single mating type. This is the first study to document evidence for the potential of sexual reproduction to occur in M. grisea isolates not associated with rice (Oryza sativa). Moreover, given the significant host specificity and contrasting genetic structures between turfgrass-associated isolates, the recent emergence of GLS on various grass hosts in California suggests that potential cultural practices or environmental changes have become conducive for the disease and that the primary inoculum may have already been present in the state, despite the fact that two

  13. Identification of genomic loci associated with crown rust resistance in perennial ryegrass (Lolium perenne L.) divergently selected populations.

    PubMed

    Brazauskas, Gintaras; Xing, Yongzhong; Studer, Bruno; Schejbel, Britt; Frei, Ursula; Berg, Paul Ragnar; Lübberstedt, Thomas

    2013-07-01

    The inheritance of crown rust resistance in perennial ryegrass is complex with both major and minor quantitative trait loci (QTL) being detected on all seven linkage groups. However, QTL mapping populations have only few segregating alleles, limiting the transferability of results to other materials. In this study, a synthetic population was developed from four crown rust resistant and susceptible parents as starting material for a divergent selection experiment of crown rust resistance to be closer to practice in plant breeding programs, and to identify genome regions relevant across a broader range of genotypes. Following three cycles of directional selection, perennial ryegrass populations were produced with a two-fold difference in average rust resistance. Divergently selected populations were genotyped at 7 resistance gene analog-derived expressed sequence tag (RGA-derived EST) as well as 15 simple sequence repeat (SSR) loci. A test for selective neutrality (Waples test), which tests the hypothesis of genetic drift versus selection, identified significant differences in allele frequencies for 7 loci (32%). The selection effect was bidirectional with the same loci showing significant response in both positively and negatively selected populations. A region under selection represented by markers LpSSR006 and EST13 on linkage group (LG) 4 was further confirmed by colocation with two separate QTL for crown rust resistance in a VrnA, a two-way pseudo-testcross mapping population. This suggests suitability of alleles identified for introgression into perennial ryegrass germplasm, where quantitative resistance to crown rust is desired.

  14. New chloroplast microsatellite markers suitable for assessing genetic diversity of Lolium perenne and other related grass species

    PubMed Central

    Diekmann, Kerstin; Hodkinson, Trevor R.; Barth, Susanne

    2012-01-01

    Background and Aims Lolium perenne (perennial ryegrass) is the most important forage grass species of temperate regions. We have previously released the chloroplast genome sequence of L. perenne ‘Cashel’. Here nine chloroplast microsatellite markers are published, which were designed based on knowledge about genetically variable regions within the L. perenne chloroplast genome. These markers were successfully used for characterizing the genetic diversity in Lolium and different grass species. Methods Chloroplast genomes of 14 Poaceae taxa were screened for mononucleotide microsatellite repeat regions and primers designed for their amplification from nine loci. The potential of these markers to assess genetic diversity was evaluated on a set of 16 Irish and 15 European L. perenne ecotypes, nine L. perenne cultivars, other Lolium taxa and other grass species. Key Results All analysed Poaceae chloroplast genomes contained more than 200 mononucleotide repeats (chloroplast simple sequence repeats, cpSSRs) of at least 7 bp in length, concentrated mainly in the large single copy region of the genome. Nucleotide composition varied considerably among subfamilies (with Pooideae biased towards poly A repeats). The nine new markers distinguish L. perenne from all non-Lolium taxa. TeaCpSSR28 was able to distinguish between all Lolium species and Lolium multiflorum due to an elongation of an A8 mononucleotide repeat in L. multiflorum. TeaCpSSR31 detected a considerable degree of microsatellite length variation and single nucleotide polymorphism. TeaCpSSR27 revealed variation within some L. perenne accessions due to a 44-bp indel and was hence readily detected by simple agarose gel electrophoresis. Smaller insertion/deletion events or single nucleotide polymorphisms detected by these new markers could be visualized by polyacrylamide gel electrophoresis or DNA sequencing, respectively. Conclusions The new markers are a valuable tool for plant breeding companies, seed testing

  15. Novel secoiridoid lactones from Jasminum multiflorum.

    PubMed

    Shen, Y C; Chen, C H

    1989-01-01

    Four new secoiridoid lactones, jasmolactones A [1], B [2], C [3], and D [4], were isolated from the aerial part of Jasminum multiflorum. The structures of these compounds, which contain a novel bicyclic 2-oxo-oxepano[4,5-c]pyran ring system, were established by spectral analyses and chemical correlations. Pharmacological testing revealed that jasmolactones B and D possess coronary vasodilating and cardiotropic activities.

  16. Windrow burning eliminates Italian Ryegrass (Lolium perenne ssp. multiflorum) seed viability

    USDA-ARS?s Scientific Manuscript database

    Burning of crop residues that have been concentrated behind the harvest combine (windrowed) is one of several harvest weed seed control strategies that have been developed and evaluated in Australia to address the widespread evolution of multiple herbicide resistance in annual weeds. Herbicide-resis...

  17. Does leaf manipulation affect leaf appearance in italian ryegrass (Lolium multiflorum Lam.)

    USDA-ARS?s Scientific Manuscript database

    Mechanical stimuli such as rubbing, shaking, or flexing plants can alter their growth rates and morphologies. Plant response to mechanical stress can result in delayed plant growth, reduced leaf size, shorten and thicken stems, and reduced yields. Repeated measurements, such as leaf counting or me...

  18. Distribution of polycyclic aromatic hydrocarbons in subcellular root tissues of ryegrass (Lolium multiflorum Lam.)

    PubMed Central

    2010-01-01

    Background Because of the increasing quantity and high toxicity to humans of polycyclic aromatic hydrocarbons (PAHs) in the environment, several bioremediation mechanisms and protocols have been investigated to restore PAH-contaminated sites. The transport of organic contaminants among plant cells via tissues and their partition in roots, stalks, and leaves resulting from transpiration and lipid content have been extensively investigated. However, information about PAH distributions in intracellular tissues is lacking, thus limiting the further development of a mechanism-based phytoremediation strategy to improve treatment efficiency. Results Pyrene exhibited higher uptake and was more recalcitrant to metabolism in ryegrass roots than was phenanthrene. The kinetic processes of uptake from ryegrass culture medium revealed that these two PAHs were first adsorbed onto root cell walls, and they then penetrated cell membranes and were distributed in intracellular organelle fractions. At the beginning of uptake (< 50 h), adsorption to cell walls dominated the subcellular partitioning of the PAHs. After 96 h of uptake, the subcellular partition of PAHs approached a stable state in the plant water system, with the proportion of PAH distributed in subcellular fractions being controlled by the lipid contents of each component. Phenanthrene and pyrene primarily accumulated in plant root cell walls and organelles, with about 45% of PAHs in each of these two fractions, and the remainder was retained in the dissolved fraction of the cells. Because of its higher lipophilicity, pyrene displayed greater accumulation factors in subcellular walls and organelle fractions than did phenanthrene. Conclusions Transpiration and the lipid content of root cell fractions are the main drivers of the subcellular partition of PAHs in roots. Initially, PAHs adsorb to plant cell walls, and they then gradually diffuse into subcellular fractions of tissues. The lipid content of intracellular components determines the accumulation of lipophilic compounds, and the diffusion rate is related to the concentration gradient established between cell walls and cell organelles. Our results offer insights into the transport mechanisms of PAHs in ryegrass roots and their diffusion in root cells. PMID:20860818

  19. Management of an ACCase-inhibitor-resistant Lolium rigidum population based on the use of ALS inhibitors: weed population evolution observed over a 7 year field-scale investigation.

    PubMed

    Collavo, Alberto; Strek, Harry; Beffa, Roland; Sattin, Maurizio

    2013-02-01

    A 7 year experiment was set up in 2002 to evaluate the long-term effects of weed management strategies based on graminicidal sulfonylureas (SUs) on the evolution of a Lolium rigidum population resistant to ACCase inhibitors in a continuous wheat cropping system. The strategies included the continued use of ALS inhibitors, the continued application of ACCase inhibitors and a simple resistance management strategy based on a biennial rotation of herbicide mode of action (MoA). The efficacy of the tested SUs in the field decreased significantly, starting from the fourth treatment in all control strategies. Regardless of control strategy, the few survivors of the ALS treatment in the third season produced a significant number of ACCase- and ALS-resistant (multiple-resistant) progeny. Continuous ALS and biennial rotation of herbicides reduced weed densities, but L. rigidum conserved its ACCase resistance trait. Enhanced metabolism was detected in ALS-resistant plants, whereas target site was primarily involved in the ACCase-resistant individuals. At the end of the experiment, multiple-resistant individuals were found in all samples coming from the control strategies investigated. The biennial rotation between ALS and other MoA appeared to delay the development of resistance to SUs over continuous treatments, but additional measures will likely need to be taken in order to make this sustainable in the long term, whereas the field efficacy of SUs remained relatively high until the end of the experiment. Integrated weed management with more diversity should be introduced in oversimplified cropping systems in order to sustainably manage resistant L. rigidum populations. Copyright © 2012 Society of Chemical Industry.

  20. Effects of elevated CO2 levels on root morphological traits and Cd uptakes of two Lolium species under Cd stress*

    PubMed Central

    Jia, Yan; Tang, Shi-rong; Ju, Xue-hai; Shu, Li-na; Tu, Shu-xing; Feng, Ren-wei; Giusti, Lorenzino

    2011-01-01

    This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam. and Lolium perenne L. exposed to two CO2 levels (360 and 1000 μl/L) and three Cd levels (0, 4, and 16 mg/L) under hydroponic conditions. The results show that elevated levels of CO2 increased shoot biomass more, compared to root biomass, but decreased Cd concentrations in all plant tissues. Cd exposure caused toxicity to both Lolium species, as shown by the restrictions of the root morphological parameters including root length, surface area, volume, and tip numbers. These parameters were significantly higher under elevated levels of CO2 than under ambient CO2, especially for the number of fine roots. The increases in magnitudes of those parameters triggered by elevated levels of CO2 under Cd stress were more than those under non-Cd stress, suggesting an ameliorated Cd stress under elevated levels of CO2. The total Cd uptake per pot, calculated on the basis of biomass, was significantly greater under elevated levels of CO2 than under ambient CO2. Ameliorated Cd toxicity, decreased Cd concentration, and altered root morphological traits in both Lolium species under elevated levels of CO2 may have implications in food safety and phytoremediation. PMID:21462388

  1. Leaf Rubisco turnover in a perennial ryegrass (Lolium perenne L.) mapping population: genetic variation, identification of associated QTL, and correlation with plant morphology and yield.

    PubMed

    Khaembah, Edith N; Irving, Louis J; Thom, Errol R; Faville, Marty J; Easton, H Sydney; Matthew, Cory

    2013-03-01

    This study tested the hypotheses that: (i) genetic variation in Rubisco turnover may exist in perennial ryegrass (Lolium perenne L.); (ii) such variation might affect nitrogen use efficiency and plant yield; and (iii) genetic control of Rubisco turnover might be amenable to identification by quantitative trait loci (QTL) mapping. A set of 135 full-sib F1 perennial ryegrass plants derived from a pair cross between genotypes from the cultivars 'Grasslands Impact' and 'Grasslands Samson' was studied to test these hypotheses. Leaf Rubisco concentration at different leaf ages was measured and modelled as a log-normal curve described by three mathematical parameters: D (peak Rubisco concentration), G (time of D), and F (curve standard deviation). Herbage dry matter (DM) yield and morphological traits (tiller weight (TW), tiller number (TN), leaf lamina length (LL), and an index of competitive ability (PI)) were also measured. The progeny exhibited continuous variation for all traits. Simple correlation and principal component analyses indicated that plant productivity was associated with peak Rubisco concentration and not Rubisco turnover. Lower DM was associated with higher leaf Rubisco concentration indicating that Rubisco turnover effects on plant productivity may relate to energy cost of Rubisco synthesis rather than photosynthetic capacity. QTL detection by a multiple QTL model identified seven significant QTL for Rubisco turnover and nine QTL for DM and morphological traits. An indication of the genetic interdependence of DM and the measures of Rubisco turnover was the support interval overlap involving QTL for D and QTL for TN on linkage group 5 in a cluster involving QTL for DM and PI. In this region, alleles associated with increased TN, DM, and PI were associated with decreased D, indicating that this region may regulate Rubisco concentration and plant productivity via increased tillering. A second cluster involving QTL for LL, TN, PI and DM was found on

  2. Decondensation of chromosomal 45S rDNA sites in Lolium and Festuca genotypes does not result in karyotype instability.

    PubMed

    Rocha, Laiane Corsini; Jankowska, Maja; Fuchs, Joerg; Mittelmann, Andréa; Techio, Vânia Helena; Houben, Andreas

    2017-01-01

    Fragile sites (FSs) in plants have been described for species like Lolium and other grasses. Whereas in humans FSs were shown to be involved in genome instabilities; the consequences of FSs expression in plants are not known yet. To evaluate whether FSs cause karyotype instabilities, we assessed the frequency of micronuclei and lagging chromosomes in meristematic cells, the stability of the DNA content, and the occurrence of neocentromeres in the presumed chromosomal fragments of Lolium perenne, Lolium multiflorum, Festuca arrundinacea, and two Festulolium hybrids. The cell cycle analysis along with flow cytometric genome size measurements showed high stability in all genomes evaluated. Neocentromeric activity was neither observed in the presumed fragments nor in any other chromosomal region, then this is not the mechanism responsible by the stability. However, Fluorescence in situ hybridization (FISH) with a 45S ribosomal DNA (rDNA) probe in combination with YOYO staining of metaphasic chromosomes showed that many extended nucleolus organizing region (NOR) form very thin YOYO-positive chromatin fibers connecting the acentric 'fragment' with the centromere-containing chromosome region. The obtained data indicate that the expression of FSs does not result in genome instabilities or neocentromere formation. The FS-containing 45S rDNA carrying chromatin fibers undergo a cell cycle and gene activity-dependent dynamic decondensation process.

  3. Allelopathic effect of Bromus spp. and Lolium spp. shoot extracts on some crops.

    PubMed

    Lehoczky, E; Nelima, M Okumu; Szabó, R; Szalai, A; Nagy, P

    2011-01-01

    Allelopathy is an untapped resource for weed control in crops that could give good possibilities for environmentally sound, integrated crop production. Allelopathy is defined as the direct or indirect harmful or beneficial effects of one plant on another through the production of chemical compounds, called allelochemicals, which escape into the environment. Allelochemicals can be produced by weeds and affect crops, and the reverse is also true. Allelopathic interactions include weed-weed, weed-crop, and crop-crop. Allelopathy offers potential for selective biological weed control for instance weed-suppressing crops and the use of plant residues in cropping systems, allelopathic rotational crops, or companion plants with allelopathic potential. Bromus species occur in many habitats in temperate regions of the world, including America, Eurasia, Australia, and Africa. The genus Lolium is one of the most important forage grasses. The weed species usually grow in the same production zones as wheat and are considered weeds since they parasitize wheat fields. Some of the weed species in these two genus have been reported to have allelopathic effect. One of the methods that has been successful in studying allelopathic activity are bioassays. Laboratory experiments were conducted to determine allelopathic effect of watery shoot extracts of four weed species of the Poaceae family, namely Bromus rigidus, Bromus diandrus, Lolium multiflorum and Lolium temulentum on germination and growth of winter wheat (Triticum aestivum L.), spring barley (Hordeum vulgare L.), corn (Zea mays L), perennial ryegrass (Lolium perenne L.), bean (Phaseolus sp.) and sunflower (Helianthus annuus L.) and on each other. The experiment was carried out during the period March 2010 to October 2010. Twenty five seeds were put into one Petri-dish on filter paper, adding 15ml of extract to each in four repeats. The germination took place in a Binder-type thermostat in the dark. The timing of germination was

  4. Feeding strategies for small-scale dairy systems based on perennial (Lolium perenne) or annual (Lolium multiflorum) ryegrass in the central highlands of Mexico.

    PubMed

    Heredia-Nava, D; Espinoza-Ortega, A; González-Esquivel, C E; Arriaga-Jordán, C M

    2007-04-01

    Small-scale dairying is an option for campesinos in Mexico. The costs of feeding are high and strategies based on quality forages are a priority. The performance, agronomic variables and feeding costs were evaluated for dairy cows continuously grazing perennial ryegrass-white clover for 9 h/day (PRG) or fed cut herbage from annual ryegrass for 8 weeks followed by 9 h/day for 6 weeks on a tethered rotational grazing pattern (ARG). All cows received 3 kg/day of an 18% crude protein (CP) concentrate. A 14-week split-plot on-farm experiment was designed with 10 cows from two participating farmers, and 1.5 ha per strategy. Milk yield was recorded weekly and milk composition, live weight and body condition score were recorded every 14 days. Net herbage accumulation was greater for ARG (8222 kg organic matter (OM)/ha) than for PRG (5915 kg OM/ha) (p<0.05), with higher CP in PRG (p<0.05). Milk yield was 19 kg/cow per day for PRG and 15.9 kg/ cow per day for ARG (p>0.05). Over 14 weeks, PRG produced 1422 kg more milk. There were no differences for live weight or condition score (p>0.05), but linear regression shows a live weight gain of 0.200 kg/cow per day for PRG. Protein and fat content showed no differences (p>0.05), but milk fat content in PRG was below standard. ARG had 60% higher costs, and margins were 38% higher in PRG. ARG has a place in rain-fed fields. The results provide viable options for improving these systems that may be suitable in their socio-economic context and their social and personal objectives.

  5. Linkage Disequilibrium Among Two Lolium Perenne CBF Genes and Association With Freezing Susceptibility

    USDA-ARS?s Scientific Manuscript database

    Perennial ryegrass(Lolium perenne) is one of the most abundantly utilized forage and turfgrass species; however, its lack of tolerance to freezing temperatures relative to other forage/turf grasses limits its use. A pseudo-testcross genetic mapping population was previously developed for perennial ...

  6. Phenanthrene and Pyrene Modify the Composition and Structure of the Cultivable Endophytic Bacterial Community in Ryegrass (Lolium multiflorum Lam)

    PubMed Central

    Zhu, Xuezhu; Jin, Li; Sun, Kai; Li, Shuang; Li, Xuelin; Ling, Wanting

    2016-01-01

    This study provides new insights into the dynamics of bacterial community structure during phytoremediation. The communities of cultivable autochthonous endophytic bacteria in ryegrass exposed to polycyclic aromatic hydrocarbons (PAHs) were investigated with regard to their potential to biodegrade PAHs. Bacterial counts and 16S rRNA gene sequence were used in the microbiological evaluation. A total of 33 endophytic bacterial strains were isolated from ryegrass plants, which represented 15 different genera and eight different classes, respectively. Moreover, PAH contamination modified the composition and structure of the endophytic bacterial community in the plants. Bacillus sp., Pantoea sp., Pseudomonas sp., Arthrobacter sp., Pedobacter sp. and Delftia sp. were only isolated from the seedlings exposed to PAHs. Furthermore, the dominant genera in roots shifted from Enterobacter sp. to Serratia sp., Bacillus sp., Pantoea sp., and Stenotrophomonas sp., which could highly biodegrade phenanthrene (PHE). However, the diversity of endophytic bacterial community was decreased by exposure to the mixture of PAHs, and increased by respective exposure to PHE and pyrene (PYR), while the abundance was increased by PAH exposure. The results clearly indicated that the exposure of plants to PAHs would be beneficial for improving the effectiveness of phytoremediation of PAHs. PMID:27827894

  7. Enhanced remediation of chlorpyrifos by ryegrass (Lolium multiflorum) and a chlorpyrifos degrading bacterial endophyte Mezorhizobium sp. HN3.

    PubMed

    Jabeen, Hina; Iqbal, Samina; Ahmad, Fiaz; Afzal, Muhammad; Firdous, Sadiqa

    2016-01-01

    For effective remediation of contaminants, plant-endophyte partnership is a promising field to be explored. Generally endophytic bacteria assist their host plant by withstanding the stress induced by the contaminants. The objective of this study was to explore the suitability of plant-bacterial partnership for chlorpyrifos (CP) remediation using ryegrass and a CP degrading endophyte, Mesorhizobium sp. HN3 which belongs to plant growth promoting rhizobia. The inoculated yfp-tagged Mesorhizobium sp. HN3 efficiently colonized in the rhizosphere, enhanced plant growth and degradation of CP and its metabolite 3,5,6 trichloro-2-pyridinol (TCP). Significantly lower CP residues were observed in the roots and shoots of plants vegetated in inoculated soil which might be attributed to the efficient root colonization of HN3yfp. These results suggest the involvement of Mesorhizobium sp. HN3yfp in CP degradation inside the roots and rhizosphere of plants and further emphasize on the effectiveness of endophytic bacteria in stimulating the remediation of pesticide contaminants. This is the first report which demonstrates the efficacy of bacterial endophyte for degradation of CP residues taken up by the plant and enhanced remediation of chlorpyrifos contaminated soil.

  8. Seed size effects on early seedling growth and response to applied nitrogen in annual ryegrass (Lolium multiflorum L.)

    USDA-ARS?s Scientific Manuscript database

    Use of individual plants as experimental units may be necessary when resources are limited, but inter-plant variation risks obscuring differences among treatments. Experiments were undertaken to measure the effects of seed size on seedling size and response to applied nitrogen of annual ryegrass (Lo...

  9. [Influence of specification on chemical composition of dissolution and hepatocytes toxicity of Polygonum multiflorum].

    PubMed

    lI, Yu-Meng; Li, Rui-Yu; Niu, Ming; Li, Chun-Yu; Bai, Zhao-Fang; Feng, Wu-Wen; Zhang, Cong-En; Tan, Peng; Huang, Zhi-Pu; Ma, Wei-Guang; Wang, Jia-Bo; Xiao, Xiao-He

    2016-03-01

    According to different toxicities of various aqueous extracts of Polygonum multiflorum on hepatocyte, the impacts of chemical composition on the safety of P. multiforum was studied. In this study, 8 main chemical compositions in aqueous extracts of P. multiflorum were determined by the established HPLC method; at the same time, the inhibition ratios of different aqueous extracts of P. multiflorum on L02 cell were determined. Afterwards, the potential compounds related to the toxicity of P. multiforum were tentatively found through a multiple correlation analysis. The results showed that P. multiforum with different chemical compositions exhibited great differences in dissolution. The hepatocyte toxicity of P. multiflorum powder was much greater than P. multiflorum lumps. In addition, three constituents closely related to toxicity of P. multiflorum were found by multiple correlation analysis. The study revealed that chemical composition of P. multiflorum is closely related to the hepatotoxicity, and the hepatotoxicity of P. multiflorum powder is greater than that of other dosage forms. This study indicates that P. multiflorum with different chemical compositions show varying toxicity, which therefore shall be given high attention. Copyright© by the Chinese Pharmaceutical Association.

  10. Virus induced gene silencing in Lolium temulentum

    USDA-ARS?s Scientific Manuscript database

    Lolium temulentum L. is valuable as a model species for studying abiotic stress in closely related forage and turf grasses, many of which are polyploid outcrossing species. As with most monocot species, Agrobacterium-mediated transformation of L. temulentum is still challenging, time consuming and n...

  11. Tilletia vankyi, a new species of reticulate-spored bunt fungus with non-conjugating basidiospores infecting species of Festuca and Lolium.

    PubMed

    Carris, Lori M; Castlebury, Lisa A; Huang, Guoming; Alderman, Steve C; Luo, Jiafeng; Bao, Xiaodong

    2007-12-01

    A bunt fungus, exhibiting a spore germination pattern unique to known reticulate-spored species of Tilletia was found infecting plants in seed production fields of Festuca rubra ssp. rubra (red fescue) and F. rubra ssp. fallax (Chewing's fescue) in Oregon, and in seed lots of Lolium perenne (perennial ryegrass) from Australia and Germany. Teliospores germinated to form 20-40 uninucleate, non-conjugating basidiospores, and colonies derived from single basidiospores produced teliospores in culture. In inoculation studies using single basidiospore colonies, perennial ryegrass and L. perenne ssp. multiflorum (Italian or annual ryegrass) were infected. A phylogenetic analysis, based on ITS region rDNA, eukaryotic translation elongation factor 1 alpha, and the second largest subunit of RNA polymerase II demonstrated that the fescue and ryegrass bunts are conspecific, and distinct from known species of Tilletia.

  12. Hair Growth Promotion Activity and Its Mechanism of Polygonum multiflorum

    PubMed Central

    Li, Yunfei; Han, Mingnuan; Lin, Pei; He, Yanran; Yu, Jie; Zhao, Ronghua

    2015-01-01

    Polygonum multiflorum Radix (PMR) has long history in hair growth promotion and hair coloring in clinical applications. However, several crucial problems in its clinic usage and mechanisms are still unsolved or lack scientific evidences. In this research, C57BL/6J mice were used to investigate hair growth promotion activity and possible mechanism of PMR and Polygonum multiflorum Radix Preparata (PMRP). Hair growth promotion activities were investigated by hair length, hair covered skin ratio, the number of follicles, and hair color. Regulation effects of several cytokines involved in the hair growth procedure were tested, such as fibroblast growth factor (FGF-7), Sonic Hedgehog (SHH), β-catenin, insulin-like growth factor-1 (IGF-1), and hepatocyte growth factor (HGF). Oral PMR groups had higher hair covered skin ratio (100 ± 0.00%) than oral PMRP groups (48%~88%). However, topical usage of PMRP had about 90% hair covered skin ratio. Both oral administration of PMR and topically given PMRP showed hair growth promotion activities. PMR was considered to be more suitable for oral administration, while PMRP showed greater effects in external use. The hair growth promotion effect of oral PMR was most probably mediated by the expression of FGF-7, while topical PMRP promoted hair growth by the stimulation of SHH expression. PMID:26294926

  13. [Study on determination and principal component analysis of inorganic elements in Polygonum multiflorum from different areas].

    PubMed

    Yan, Han-Jing; Fang, Zhi-Jian

    2008-02-01

    To explore the character of inorganic elements in Polygonum multiflorum. The contents of elements such as Al, B, Ba, Ca, Cu, Mn, Mg, Fe, Na, Ni, P, Se, Sr, Ti and Zn in nine P. multiflorum samples were determined by means of ICP-AEC. The results were used for the development of element distrubution diagram. The principal component analysis and one-way ANOVA of SPSS were applied for the study of characteristic elements in P. multiflorum. The contents of Al, Ca, K, Mg, Sr,Ti in wild P. multiflorum were remarkable higher than those in cultured P. multiflorum, and there was no significant difference between cultured and wild in the other elements. Five principal components which accounted for over 90% of the total variance were extracted from the original data. The analysis results show that Al, B, Ba, Fe, Na, Ni, Ti, Ca and Sr may be the characteristic elements in P. multiflorum. The element distrubution diagram of the sample from Tianyang was remarkable different comparing with the others. The principal component analysis could be used in data processing in inorganic elements.

  14. Traditional usages, botany, phytochemistry, pharmacology and toxicology of Polygonum multiflorum Thunb.: a review.

    PubMed

    Lin, Longfei; Ni, Boran; Lin, Hongmei; Zhang, Miao; Li, Xuechun; Yin, Xingbin; Qu, Changhai; Ni, Jian

    2015-01-15

    Polygonum multiflorum Thunb., which is known as Heshouwu ( in Chinese) in China. It is traditionally valued and reported for hair-blacking, liver and kidney-tonifying and anti-aging effects as well as low toxicity. The aim of this review is to provide comprehensive information on the botany, traditional uses, phytochemistry, pharmacological research and toxicology of Polygonum multiflorum, based on the scientific literature. Moreover, trends and perspectives for future investigation of this plant are discussed. It will build up a new foundation for further study on Polygonum multiflorum. A systematic review of the literature on Polygonum multiflorum was performed using several resources, including classic books on Chinese herbal medicine and various scientific databases, such as PubMed, SciFinder, the Web of Science, Science Direct, China Knowledge Resource Integrated (CNKI). Polygonum multiflorum is widely distributed throughout the world and has been used as a traditional medicine for centuries in China. The ethnomedical uses of Polygonum multiflorum have been recorded in many provinces of China and Japan for nine species of adulterants in six families. More than 100 chemical compounds have been isolated from this plant, and the major components have been determined to be stilbenes, quinones, flavonoids and others. Crude extracts and pure compounds of this plant are used as effective agents in pre-clinical and clinical practice due to their anti-aging, anti-hyperlipidaemia, anti-cancer and anti-inflammatory effects and to promote immunomodulation, neuroprotection, and the curing of other diseases. However, these extracts can also lead to hepatotoxicity, nephrotoxicity and embryonic toxicity. Pharmacokinetic studies have demonstrated that the main components of Polygonum multiflorum, such as 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucopyranoside and emodin are distributed among many organs and tissues. Therapeutic potential of Polygonum multiflorum has been

  15. Broad Resistance to ACCase Inhibiting Herbicides in a Ryegrass Population Is Due Only to a Cysteine to Arginine Mutation in the Target Enzyme

    PubMed Central

    Kaundun, Shiv Shankhar; Hutchings, Sarah-Jane; Dale, Richard Paul; McIndoe, Eddie

    2012-01-01

    Background The design of sustainable weed management strategies requires a good understanding of the mechanisms by which weeds evolve resistance to herbicides. Here we have conducted a study on the mechanism of resistance to ACCase inhibiting herbicides in a Lolium multiflorum population (RG3) from the UK. Methodology/Principal Findings Analysis of plant phenotypes and genotypes showed that all the RG3 plants (72%) that contained the cysteine to arginine mutation at ACCase codon position 2088 were resistant to ACCase inhibiting herbicides. Whole plant dose response tests on predetermined wild and mutant 2088 genotypes from RG3 and a standard sensitive population indicated that the C2088R mutation is the only factor conferring resistance to all ten ACCase herbicides tested. The associated resistance indices ranged from 13 for clethodim to over 358 for diclofop-methyl. Clethodim, the most potent herbicide was significantly affected even when applied on small mutant plants at the peri-emergence and one leaf stages. Conclusion/Significance This study establishes the clear and unambiguous importance of the C2088R target site mutation in conferring broad resistance to ten commonly used ACCase inhibiting herbicides. It also demonstrates that low levels “creeping”, multigenic, non target site resistance, is not always selected before single gene target site resistance appears in grass weed populations subjected to herbicide selection pressure. PMID:22768118

  16. Landscape effects of a non-native grass facilitate source populations of a native generalist bug, Stenotus rubrovittatus, in a heterogeneous agricultural landscape.

    PubMed

    Yoshioka, A; Takada, M B; Washitani, I

    2014-01-01

    Non-native plant species can provide native generalist insects, including pests, with novel food and habitats. It is hypothesized that local and landscape-level abundances of non-native plants can affect the population size of generalist insects, although generalists are assumed to be less sensitive to habitat connectivity than specialists. In a heterogeneous landscape in Japan, the relationship between the density of a native pest of rice (Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae)) and the abundance of Italian ryegrass (Lolium multiflorum Lam. (Poales: Poaceae)), a non-native meadow grass known to facilitate S. rubrovittatus, was analyzed. Statistical analyses of data on bug density, vegetation, and the spatial distribution of fallow fields and meadows dominated by Italian ryegrass, obtained by field surveys, demonstrated that local and landscape-level abundances of Italian ryegrass (the unmowed meadow areas within a few hundred meters of a sampling plot) positively affected bug density before its immigration into rice fields. Our findings suggest that a generalist herbivorous insect that prefers non-native plants responds to spatial availability and connectivity of plant species patches at the metapopulation level. Fragmentation by selective mowing that decreases the total area of source populations and increases the isolation among them would be an effective and environmentally-friendly pest management method.

  17. Herbicidal activity of Brassicaceae seed meal on wild oat (Avena fatua), Italian ryegrass (Lolium multiflorum Lam.), redroot pigweed (Amaranthus retroflexus L.) and prickly lettuce (Lactuca serriola)

    USDA-ARS?s Scientific Manuscript database

    There is an on-going need for the development of sustainable methods of weed control in crop production systems. Studies were conducted to evaluate the efficacy of different Brassicaceae seed meals and application rates on the emergence of several weed species including wild oat, Italian rye grass, ...

  18. Fructan synthesis, accumulation and polymer traits. II. Fructan pools in populations of perennial ryegrass (Lolium perenne L.) with variation for water-soluble carbohydrate and candidate genes were not correlated with biosynthetic activity and demonstrated constraints to polymer chain extension

    PubMed Central

    Gallagher, Joe A.; Cairns, Andrew J.; Thomas, David; Timms-Taravella, Emma; Skøt, Kirsten; Charlton, Adam; Williams, Peter; Turner, Lesley B.

    2015-01-01

    Differences have been shown between ryegrass and fescue within the Festulolium subline introgression family for fructan synthesis, metabolism, and polymer-size traits. It is well-established that there is considerable variation for water-soluble carbohydrate and fructan content within perennial ryegrass. However there is much still to be discovered about the fructan polymer pool in this species, especially in regard to its composition and regulation. It is postulated that similar considerable variation for polymer traits may exist, providing useful polymers for biorefining applications. Seasonal effects on fructan content together with fructan synthesis and polymer-size traits have been examined in diverse perennial ryegrass material comprising contrasting plants from a perennial ryegrass F2 mapping family and from populations produced by three rounds of phenotypic selection. Relationships with copy number variation in candidate genes have been investigated. There was little evidence of any variation in fructan metabolism across this diverse germplasm under these conditions that resulted in substantial differences in the complement of fructan polymers present in leaf tissue at high water-soluble carbohydrate concentrations. The importance of fructan synthesis during fructan accumulation was unclear as fructan content and polymer characteristics in intact plants during the growing season did not reflect the capacity for de novo synthesis. However, the retention of fructan in environmental conditions favoring high sink/low source demand may be an important component of the high sugar trait and the roles of breakdown and turnover are discussed. PMID:26528321

  19. Effects of Polygonum multiflorum on the activity of cytochrome P450 isoforms in rats.

    PubMed

    Zhang, Yuan; Ding, Ting; Diao, Tingting; Deng, Mengjiao; Chen, Suhong

    2015-01-01

    Polygonum multiflorum is a traditional Chinese medicinal herb used in clinical medicine to nourish the liver and kidney. However, in recent years, there have been increased reports of clinical adverse reactions associated with Polygonum multiflorum preparations, especially due to liver injury. The cocktail method can be used to assess the influence of Polygonum multiflorum on the activity of cytochrome P450 (CYP450) isoforms CYP2B6, CYP2C19, CYP2C9, CYP1A2, CYP3A4, and CYP2D6, which were reflected by changes in pharmacokinetic parameters in six specific probe drugs: bupropion, omeprazole, tolbutamide, phenacetin, midazolam, and metoprolol. Comprised the experimental rats were randomly divided into five groups: control group, alcohol extraction A group, alcohol extraction B group, water extraction A group, and water extraction B group. Each group five male rats and five female rats. Each of the groups received treatments by gavage as follows: control group was given normal saline, alcohol extraction A group was given 15 g/kg alcohol extract of Polygonum multiflorum (E15), alcohol extraction B group was given with 30 g/kg alcohol extract (E30), water extraction A group was given 15 g/kg water extract (W15), and water extraction B group was given 30 g/kg water extract (W30). The extract solution was orally administered once a day for 28 consecutive days. The mixture of six probe drugs was given by gavage, and blood samples were collected through the tail vein at different time points. Probe drug concentration in rat plasma was measured by liquid chromatography-mass spectrometry (LC-MS). In the treatment and control groups, Polygonum multiflorum alcoholic extract inhibited the activity of CYP2C19 and CYP2C9 and induced the activity of CYP1A2. Polygonum multiflorum aquous extract inhibited the activity of CYP2B6, CYP2C19, CYP2C9, CYP1A2, and CYP2D6. Pathological sections showed that in the alcohol extract group the liver was degenerated inconspicuously, and in the water

  20. Review of clinical studies of Polygonum multiflorum Thunb. and its isolated bioactive compounds

    PubMed Central

    Bounda, Guy-Armel; Feng, YU

    2015-01-01

    Polygonum multiflorum Thunb. (PMT), officially listed in the Chinese Pharmacopoeia, is one of the most popular perennial Chinese traditional medicines known as He shou wu in China and East Asia, and as Fo-ti in North America. Mounting pharmacological studies have stressed out its key benefice for the treatment of various diseases and medical conditions such as liver injury, cancer, diabetes, alopecia, atherosclerosis, and neurodegenerative diseases as well. International databases such as PubMed/Medline, Science citation Index and Google Scholar were searched for clinical studies recently published on P. multiflorum. Various clinical studies published articles were retrieved, providing information relevant to pharmacokinetics-pharmacodynamics analysis, sleep disorders, dyslipidemia treatment, and neurodegenerative diseases. This review is an effort to update the clinical picture of investigations ever carried on PMT and/or its isolated bio-compounds and to enlighten its therapeutic assessment. PMID:26130933

  1. [Rapid Identification of Chemical Components in Polygonum multiflorum Formula Granules by UPLC/Q-TOF MS].

    PubMed

    Xu, Ai-li; Dong, Yu-juan; Chen, Zhao; Jiang, Jie-yi; Li, Su-mei; Li, Yang-xue

    2015-06-01

    To establish a simple and reliable method for rapid separation and identification of chemical components in Polygonum multiflorum Formula Granules. An ultra-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometric method( UPLC/Q-TOF MS) was used. The separation was performed on an Agilent Eclipse Plus C18 RRHD(100 mm x 2.1 mm, 1.8 μm) column with a mobile phase of water and acetonitrile in a gradient elution mode. The flow rate was 0.4 mL/min and the column temperature was maintained at 25 degrees C. TOF MS was applied for qualitative analysis under positive ion mode. Five compounds were identified by the time of flight mass spectrometry and literature data. This method is accurate, rapid and sensitive, it can provide reference for the quality control of Polygonum multiflorum Formula Granules.

  2. Acute hepatitis induced by Shou-Wu-Pian, a herbal product derived from Polygonum multiflorum.

    PubMed

    Park, G J; Mann, S P; Ngu, M C

    2001-01-01

    Herbal preparations are widely available and generally regarded by the public as harmless remedies for a variety of medical ailments. We report the first case in Australia of acute hepatitis associated with the Chinese herbal medicine Shou-Wu-Pian, prepared from Polygonum multiflorum. Cholestatic hepatitis developed in a Chinese woman taking this preparation for the greying of her hair, and liver biopsy was consistent with a toxic reaction. Clinical and biochemical resolution occurred following cessation of the drug.

  3. Polygonumnolides C1-C4; minor dianthrone glycosides from the roots of Polygonum multiflorum Thunb.

    PubMed

    Yang, Jian-Bo; Li, Li; Dai, Zhong; Wu, Yu; Geng, Xing-Chao; Li, Bo; Ma, Shuang-Cheng; Wang, Ai-Guo; Su, Ya-Lun

    2016-09-01

    Four new dianthrone glycosides, named polygonumnolides C1-C4 (1-4), were isolated from the dried roots of Polygonum multiflorum Thunb, together with two known emodin dianthrones (5-6). Their hepatotoxicities were evaluated against L-02 cell lines. Compounds 1-4 showed weak hepatotoxicity against L-02 cell lines with IC50 values of 313.05, 205.20, 294.20, and 207.35 μM, respectively.

  4. MICROWAVE-ASSISTED EXTRACTION OF PHENOLIC COMPOUNDS FROM POLYGONUM MULTIFLORUM THUNB. ROOTS.

    PubMed

    Quoc, Le Pham Tan; Muoi, Nguyen Van

    2016-01-01

    The aim of this study was to determine the best extraction conditions for total phenolic content (TPC) and antioxidant capacity (AC) of Polygonum multiflorum Thunb. root using microwave-assisted extraction (MAE). The raw material used was Polygonum multiflorum Thunb. root powder. Five factors such as solvent type, solvent concentrations, solvent/material ratio, extraction time and microwave power were studied; TPC and AC values were determined by the Folin-Ciocalteu method and DPPH free radical scavenging activity measurement, respectively. In addition, studies involved assaying the HPLC test of extracts and SEM of samples. Optimal results pointed to acetone as the solvent, acetone concentration of 60%, solvent/material ratio of 40/1 (v/w), extraction time of 5 mins and microwave power of 127 W. TPC and AC obtained were approximates 44.3 ±0.13 mg GAE/g DW and 341.26 ±1.54 μmol TE/g DW, respectively. The effect of microwaving on the cell destruction of Polygonum multiflorum Thunb. root was observed by scanning electron microscopy (SEM). Some phenolic compounds were determined by the HPLC method, for instance, gallic acid, catechin and resveratrol. These factors significantly affected TPC and AC. We can use acetone as a solvent with microwave-assisted extraction to achieve the best result.

  5. Transcriptome changes in Polygonum multiflorum Thunb. roots induced by methyl jasmonate* #

    PubMed Central

    Liu, Hong-chang; Wu, Wei; Hou, Kai; Chen, Jun-wen; Zhao, Zhi

    2015-01-01

    Transcriptome profiling has been widely used to analyze transcriptomic variation in plants subjected to abiotic or biotic stresses. Although gene expression changes induced by methyl jasmonate (MeJA) have been profiled in several plant species, no information is available on the MeJA-triggered transcriptome response of Polygonum multiflorum Thunb., a species with highly valuable medicinal properties. In this study, we used transcriptome profiling to investigate transcriptome changes in roots of P. multiflorum seedlings subjected to a 0.25 mmol/L-MeJA root irrigation treatment. A total of 18 677 differentially expressed genes (DEGs) were induced by MeJA treatment, of which 4535 were up-regulated and 14 142 were down-regulated compared with controls. These DEGs were associated with 125 metabolic pathways. In addition to various common primary and secondary metabolic pathways, several secondary metabolic pathways related to components with significant pharmacological effects were enriched by MeJA, including arachidonic acid metabolism, linoleic acid metabolism, and stilbenoid biosynthesis. The MeJA-induced transcriptome changes uncovered in this study provide a solid foundation for future study of functional genes controlling effective components in secondary metabolic pathways of P. multiflorum. PMID:26642186

  6. Chemical control of herbicide-resistant Lolium rigidum Gaud. in north-eastern Spain.

    PubMed

    Cirujeda, Alicia; Taberner, Andreu

    2010-12-01

    Lolium rigidum Gaud. is one of the most common weed species in winter cereals in north-eastern Spain, with populations that have evolved resistance to herbicides becoming more widespread since the mid-1990s. Nine trials on commercial fields with herbicide-resistant L. rigidum were conducted during the cropping seasons 2001-2002 to 2003-2004, testing the efficacy of 20 herbicides and mixtures pre- and post-emergence and as sequential applications. Weed populations chosen had different resistance patterns to chlortoluron, chlorsulfuron, diclofop-methyl and tralkoxydim, representative of the resistance problems faced by farmers. In pre-emergence, prosulfocarb mixed with trifluralin, chlortoluron or triasulfuron was effective on six populations. In post-emergence, iodosulfuron alone or mixed with mesosulfuron gave the best results but did not control three resistant populations. At Ferran 1, none of the herbicide combinations reached 90% efficacy. The diverse efficacy patterns of the different populations demonstrate the need for detailed knowledge of the populations before using herbicides. Moreover, the unexpected insufficient efficacy of the new herbicide iodosulfuron prior to its field use shows the need to combine herbicides with other non-chemical weed control methods to control resistant L. rigidum in north-eastern Spain. Copyright © 2010 Society of Chemical Industry.

  7. Deep sequencing reveals transcriptome re-programming of Polygonum multiflorum thunb. roots to the elicitation with methyl jasmonate.

    PubMed

    Liu, Hongchang; Wu, Wei; Hou, Kai; Chen, Junwen; Zhao, Zhi

    2016-02-01

    The phytohormone methyl jasmonate (MeJA) has been successfully used as an effective elicitor to enhance production of stilbenoid which is induced in plants as a secondary metabolite possibly in defense against herbivores and pathogens. However, the mechanism of MeJA-mediated stilbenoid biosynthesis remains unclear. Genomic information for Polygonum multiflorum Thunb. (P. multiflorum) is currently unavailable. To obtain insight into the global regulation mechanism of MeJA in the steady state of stilbene glucoside production (26 h after MeJA elicitation), especially on stilbene glucoside biosynthesis, we sequenced the transcriptomes of MeJA-treated and untreated P. multiflorum roots and obtained more than 51 million clean reads, from which 79,565 unigenes were obtained by de novo assembly. 56,972 unigenes were annotated against databases including Nr, Nt, Swiss-Prot, KEGG and COG. 18,677 genes expressed differentially between untreated and treated roots. Expression level analysis indicated that a large number of genes were associated with plant-pathogen interaction, plant hormone signal transduction, stilbenoid backbone biosynthesis, and phenylpropanoid biosynthesis. 15 known genes involved in the biosynthesis of stilbenoid backbone were found with 7 genes showing increased transcript abundance following elicitation of MeJA. The significantly up (down)-regulated changes of 70 genes in stilbenoid biosynthesis were validated by qRT-PCR assays and PCR product sequencing. According to the expression changes and the previously proposed enzyme functions, multiple candidates for the unknown steps in stilbene glucoside biosynthesis were identified. We also found some genes putatively involved in the transcription factors. This comprehensive description of gene expression information could greatly facilitate our understanding of the molecular mechanisms of MeJA-mediated stilbenoid biosynthesis in P. multiflorum roots. Our results shed new light on the global regulation

  8. Aploneura lentisci (Homoptera: Aphididae) and Its Interactions with Fungal Endophytes in Perennial Ryegrass (Lolium perenne)

    PubMed Central

    Popay, Alison J.; Cox, Neil R.

    2016-01-01

    Aploneura lentisci Pass. is endemic to the Mediterranean region where it is holocyclic, forming galls on its primary host, Pistacia lentiscus and alternating over a 2-year period between Pistacia and secondary hosts, principally species of Gramineae. This aphid is widely distributed in Australia and New Zealand on the roots of the common forage grasses, ryegrass (Lolium spp.) and tall fescue (Schedonorus phoenix) where it exists as permanent, anholocyclic, parthenogenetic populations. Previous studies have indicated that infestations of A. lentisci significantly reduce plant growth and may account for differences in field performance of Lolium perenne infected with different strains of the fungal endophyte Epichloë festucae var. lolii. These obligate biotrophs protect their host grasses from herbivory via the production of alkaloids. To confirm the hypothesis that growth of L. perenne is associated with the effect of different endophyte strains on aphid populations, herbage and root growth were measured over time in two pot trials that compared three fungal endophyte strains with an endophyte-free control. In both pot trials, aphid numbers were lowest on plants infected with endophyte strain AR37 at all sampling times. In plants infected with a common toxic strain naturalized in New Zealand, aphid numbers overall were lower than on uninfected plants or those infected with strain AR1, but numbers did not always differ significantly from these treatments. Populations on AR1-infected plants were occasionally significantly higher than those on endophyte-free. Cumulative foliar growth was reduced in AR1 and Nil treatments relative to AR37 in association with population differences of A. lentisci in both trials and root dry weight was reduced in one trial. In four Petri dish experiments survival of A. lentisci on plants infected with AR37 declined to low levels after an initial phase of up to 19 days during which time aphids fed and populations were similar to those on

  9. [Studies on biotransformation of arbutin by 4-hydroxy phenol in hairy root of Polygonum multiflorum].

    PubMed

    Yan, Chun-yan; Zhang, Zhang; Yu, Rong-min; Kong, Ling-yi

    2007-02-01

    To study the biotransformation of arbutin by 4-hydroxy phenol in hairy root of Polygonum multiflorum. 4-hydroxy phenol was used as substrate, the standard curve was made by HPLC, and the influences of the co-culture time, the concentration of substrate added and the volume of culture flasks on biotransformation of arbutin were measured by the index of the production yield and transform rate of arbutin. Arbutin could be detected from both of the cultures and medium. The correlation curve of arbutin: Y = 440740X - 1.473 (r = 0.9997). The production yield (2.22 g x L(-1)) and conversion ratio (81.45%) of arbutin reached the maximum amount as co-culture time at 72 h, substrate added in medium for 1100 mg x L(-1). Furthermore a large-scale culture of 3 L was also successful in our experiment. It was firstly to biosynthesis arbutin in hairy root of P. multiflorum. The production yield and trasfer rate of arbutin were increased largely. And large-scale production (3 L culture flask) of arbutin was achieved in the experiment and it would be valuable for the industrial production of arbutin by biotechnological method in the future.

  10. Ultrasonic-assisted extraction, structure and antitumor activity of polysaccharide from Polygonum multiflorum.

    PubMed

    Zhu, Weili; Xue, Xiaoping; Zhang, Zhanjun

    2016-10-01

    Polygonum multiflorum is a popular Chinese herbal medicine with various pharmacological functions. In this study, the ultrasonic-assisted extraction condition, structural characterization and antitumor activity of a polysaccharide from roots of P. multiflorum were investigated. The ultrasonic-assisted extraction condition was optimized by single-factor experiments and response surface methodology. Results showed that the maximum extraction yield (5.49%) was obtained at ultrasonic power 158W, extraction temperature 62°C, extraction time 80min and ratio of water to material 20mL/g. The obtained crude polysaccharides were further purified to afford a neutral and an acidic fraction. The structure of the main neutral polysaccharide (named PPS with molecular weight of 3.26×10(5)Da) was characterized as a linear (1→6)-α-d-glucan by gas chromatography, Fourier transform-infrared spectroscopy, methylation analysis, 1D and 2D nuclear magnetic resonance. At the concentration of 400μg/mL, the inhibitory ratios of PPS on HepG-2 and BGC-823 cells were 53.35% and 38.58%, respectively. Results suggested this polysaccharide could be a potential natural antitumor agent. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Polygonum multiflorum Decreases Airway Allergic Symptoms in a Murine Model of Asthma.

    PubMed

    Lee, Chen-Chen; Lee, Yueh-Lun; Wang, Chien-N; Tsai, Hsing-Chuan; Chiu, Chun-Lung; Liu, Leroy F; Lin, Hung-Yun; Wu, Reen

    2016-01-01

    The root of Polygonum multiflorum (also called He-Shou-Wu in Chinese) is a common herb and medicinal food in Asia used for its anti-aging properties. Our study investigated the therapeutic potential of an extract of the root of Polygonum multiflorum (PME) in allergic asthma by using a mouse model. Feeding of 0.5 and 1 mg/mouse PME inhibited ovalbumin (OVA)-induced allergic asthma symptoms, including airway inflammation, mucus production, and airway hyper-responsiveness (AHR), in a dose-dependent manner. To discern PME's mechanism of action, we examined the profile and cytokine production of inflammatory cells in bronchial alveolar lavage fluid (BALF). We found that eosinophils, the main inflammatory cell infiltrate in the lung of OVA-immunized mice, significantly decreased after PME treatment. Th2 cytokine levels, including interleukin (IL)-4, IL-5, IL-13, eotaxin, and the proinflammatory cytokine tumor necrosis factor (TNF)-[Formula: see text], decreased in PME-treated mice. Elevated mRNA expression of Th2 transcription factor GATA-3 in the lung tissue was also inhibited after oral feeding of PME in OVA-immunized mice. Thus, we conclude that PME produces anti-asthma activity through the inhibition of Th2 cell activation.

  12. De novo Sequencing and Comparative Transcriptomics of Floral Development of the Distylous Species Lithospermum multiflorum

    PubMed Central

    Cohen, James I.

    2016-01-01

    Genes controlling the morphological, micromorphological, and physiological components of the breeding system distyly have been hypothesized, but many of the genes have not been investigated throughout development of the two floral morphs. To this end, the present study is an examination of comparative transcriptomes from three stages of development for the floral organs of the morphs of Lithospermum multiflorum. Transcriptomes of flowers of the two morphs, from various stages of development, were sequenced using an Illumina HiSeq 2000. The floral transcriptome of L. multiflorum was assembled, and differential gene expression (DE) was identified between morphs, throughout development. Additionally, Gene Ontology (GO) terms for DE genes were determined. Fewer genes were DE early in development compared to later in development, with more genes highly expressed in the gynoecium of the SS morph and the corolla and androecium of the LS morph. A reciprocal pattern was observed later in development, and many more genes were DE during this latter stage. During early development, DE genes appear to be involved in growth and floral development, and during later development, DE genes seem to affect physiological functions. Interestingly, many genes involved in response to stress were identified as DE between morphs. PMID:28066486

  13. Remodeling of Leaf Cellular Glycerolipid Composition under Drought and Re-hydration Conditions in Grasses from the Lolium-Festuca Complex.

    PubMed

    Perlikowski, Dawid; Kierszniowska, Sylwia; Sawikowska, Aneta; Krajewski, Paweł; Rapacz, Marcin; Eckhardt, Änne; Kosmala, Arkadiusz

    2016-01-01

    Drought tolerant plant genotypes are able to maintain stability and integrity of cellular membranes in unfavorable conditions, and to regenerate damaged membranes after stress cessation. The profiling of cellular glycerolipids during drought stress performed on model species such as Arabidopsis thaliana does not fully cover the picture of lipidome in monocots, including grasses. Herein, two closely related introgression genotypes of Lolium multiflorum (Italian ryegrass) × Festuca arundinacea (tall fescue) were used as a model for other grass species to describe lipid rearrangements during drought and re-hydration. The genotypes differed in their level of photosynthetic capacity during drought, and in their capacity for membrane regeneration after stress cessation. A total of 120 lipids, comprising the classes of monogalactosyldiacyloglycerol, digalactosyldiacyloglycerol, sulfoquinovosyldiacylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, diacylglicerol, and triacylglicerol, were analyzed. The results clearly showed that water deficit had a significant impact on lipid metabolism in studied forage grasses. It was revealed that structural and metabolic lipid species changed their abundance during drought and re-watering periods and some crucial genotype-dependent differences were also observed. The introgression genotype characterized by an ability to regenerate membranes after re-hydration demonstrated a higher accumulation level of most chloroplast and numerous extra-chloroplast membrane lipid species at the beginning of drought. Furthermore, this genotype also revealed a significant reduction in the accumulation of most chloroplast lipids after re-hydration, compared with the other introgression genotype without the capacity for membrane regeneration. The potential influence of observed lipidomic alterations on a cellular membrane stability and photosynthetic capacity, are discussed

  14. Remodeling of Leaf Cellular Glycerolipid Composition under Drought and Re-hydration Conditions in Grasses from the Lolium-Festuca Complex

    PubMed Central

    Perlikowski, Dawid; Kierszniowska, Sylwia; Sawikowska, Aneta; Krajewski, Paweł; Rapacz, Marcin; Eckhardt, Änne; Kosmala, Arkadiusz

    2016-01-01

    Drought tolerant plant genotypes are able to maintain stability and integrity of cellular membranes in unfavorable conditions, and to regenerate damaged membranes after stress cessation. The profiling of cellular glycerolipids during drought stress performed on model species such as Arabidopsis thaliana does not fully cover the picture of lipidome in monocots, including grasses. Herein, two closely related introgression genotypes of Lolium multiflorum (Italian ryegrass) × Festuca arundinacea (tall fescue) were used as a model for other grass species to describe lipid rearrangements during drought and re-hydration. The genotypes differed in their level of photosynthetic capacity during drought, and in their capacity for membrane regeneration after stress cessation. A total of 120 lipids, comprising the classes of monogalactosyldiacyloglycerol, digalactosyldiacyloglycerol, sulfoquinovosyldiacylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, diacylglicerol, and triacylglicerol, were analyzed. The results clearly showed that water deficit had a significant impact on lipid metabolism in studied forage grasses. It was revealed that structural and metabolic lipid species changed their abundance during drought and re-watering periods and some crucial genotype-dependent differences were also observed. The introgression genotype characterized by an ability to regenerate membranes after re-hydration demonstrated a higher accumulation level of most chloroplast and numerous extra-chloroplast membrane lipid species at the beginning of drought. Furthermore, this genotype also revealed a significant reduction in the accumulation of most chloroplast lipids after re-hydration, compared with the other introgression genotype without the capacity for membrane regeneration. The potential influence of observed lipidomic alterations on a cellular membrane stability and photosynthetic capacity, are discussed

  15. Polygonum multiflorum Radix extract protects human foreskin melanocytes from oxidative stress in vitro and potentiates hair follicle pigmentation ex vivo.

    PubMed

    Sextius, P; Betts, R; Benkhalifa, I; Commo, S; Eilstein, J; Massironi, M; Wang, P; Michelet, J-F; Qiu, J; Tan, X; Jeulin, S

    2017-08-01

    To examine the ability of an extract from traditional Chinese medicine, Polygonum multiflorum Radix, to protect melanocyte viability from oxidative stress, a key mechanism in the initiation and progression of hair greying. To assess the antioxidant capacity of Polygonum multiflorum Radix extract, primary human foreskin melanocytes were treated with a commercially available Polygonum multiflorum Radix extract added to culture medium and exposed to hydrogen peroxide (H2 O2 ), using intracellular reactive oxygen species concentrations and glutathione/protein ratios as endpoints. To improve solubility for cosmetic uses, a new Polygonum multiflorum Radix extract was derived. As hair greying is the consequence of melanocyte disappearance in an oxidative stress environment, we checked whether the antioxidant capacity of the new Polygonum multiflorum Radix extract could preserve melanocyte viability in response to H2 O2 -induced oxidative stress, and preserve pigmentation within ex vivo human hair follicles. In vitro treatment of primary human foreskin melanocytes with traditional available Polygonum multiflorum Radix extract resulted in decreased intracellular ROS accumulation in response to H2 O2 exposure with a concomitant preservation of glutathione-to-protein ratio, consistent with a protective response against H2 O2 exposure and demonstrating the promise of this extract for protecting melanocytes against oxidative stress. Melanocytes treated with the improved Polygonum multiflorum Radix extract exhibited attenuated H2 O2 -induced cell death, demonstrating a clear cytoprotective effect. Treatment of ex vivo human hair follicles with the improved Polygonum multiflorum Radix extract resulted in a higher level of melanin compared to vehicle-treated controls, demonstrating an ex vivo protective effect on hair pigmentation. Polygonum multiflorum Radix extract protects in vitro primary human foreskin melanocytes from the deleterious effects of H2 O2 exposure and

  16. Germplasm dynamics: the role of ecotypic diversity in shaping the patterns of genetic variation in Lolium perenne

    PubMed Central

    Blackmore, T.; Thorogood, D.; Skøt, L.; McMahon, R.; Powell, W.; Hegarty, M.

    2016-01-01

    Perennial ryegrass (Lolium perenne) is the most widely grown temperate grass species globally. Intensive plant breeding in ryegrass compared to many other crops species is a relatively recent exercise (last 100 years) and provides an interesting experimental system to trace the extent, impact and trajectory of undomesticated ecotypic variation represented in modern ryegrass cultivars. To explore germplasm dynamics in Lolium perenne, 2199 SNPs were genotyped in 716 ecotypes sampled from 90 European locations together with 249 cultivars representing 33 forage/amenity accessions. In addition three pseudo-cross mapping populations (450 individual recombinants) were genotyped to create a consensus genetic linkage map. Multivariate analyses revealed strong differentiation between cultivars with a small proportion of the ecotypic variation captured in improved cultivars. Ryegrass cultivars generated as part of a recurrent selection programme (RSP) are strongly associated with a small number of geographically localised Italian ecotypes which were among the founders of the RSP. Changes in haplotype frequency revealed signatures of selection in genes putatively involved in water-soluble carbohydrate (WSC) accumulation (a trait selected in the RSP). Retrospective analysis of germplasm in breeding programmes (germplasm dynamics) provides an experimental framework for the identification of candidate genes for novel traits such as WSC accumulation in ryegrass. PMID:26935901

  17. Vernalization Mediated Changes in the Lolium perenne Transcriptome

    PubMed Central

    Paina, Cristiana; Byrne, Stephen L.; Domnisoru, Cristian; Asp, Torben

    2014-01-01

    Vernalization is a key requirement for the induction of flowering in perennial ryegrass (Lolium perenne L.). The transcriptome of two genotypes with contrasting vernalization requirement was studied during primary (vernalization and short day conditions) and secondary induction (higher temperature and long day conditions) using an RNA-Seq approach. This revealed transcripts with expression profiles indicative of a role in floral induction, both in the promotion and repression of flowering. We observed similarities and specific differences between the two genotypes related to cold response, carbohydrate metabolism, and photoperiod regulation. Components of the photoperiod pathway showed regulation during vernalization, pointing to possible interactions between elements of the photoperiod and vernalization pathways. The results provide a global picture of the processes ongoing during the transition from vegetative to reproductive phase of perennial ryegrass genotypes with and without a vernalization requirement. PMID:25225807

  18. Production of anthraquinones, phenolic compounds and biological activities from hairy root cultures of Polygonum multiflorum Thunb.

    PubMed

    Thiruvengadam, Muthu; Praveen, Nagella; Kim, Eun-Hye; Kim, Seung-Hyun; Chung, Ill-Min

    2014-05-01

    Polygonum multiflorum Thunb. is a highly important medicinal plant producing anthraquinones (emodin and physcion) and phenolic compounds which has pharmaceutical use. In vitro seedling explants such as roots, internodals, nodals and leaves were inoculated with A. rhizogenes strain KCTC 2703. Transformed roots were induced from internodals and leaf explants. Six transgenic clones of hairy roots were established and confirmed by polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR) using rolC specific primers. Hairy roots cultured using MS liquid medium supplemented with 30 g/l sucrose showed highest accumulation of biomass (99.05 g/l FW [fresh weight] and 10.95 g/l DW [dry weight]) and highest production of anthraquinones content (emodin 211.32 μg/g DW and physcion 353.23 μg/g DW) were observed at 20 days. Nearly 9.5-fold increment of biomass was evident in suspension cultures at 20 days of culture and hairy root biomass produced in suspension cultures possessed 3.7- and 3.5-fold higher content of emodin and physcion, respectively, when compared with the untransformed control roots. MS basal liquid medium was superior for the growth of hairy roots and production of anthraquinones compared with other culture media evaluated (SH, B5 and N6), with MS-basal liquid medium supplemented with 30 g/l sucrose was optimal for secondary metabolite production. A total of 23 polyphenolic compounds were identified and quantified from P. multiflorum untransformed and hairy roots, which includes hydroxybenzoic acids, hydroxycinnamic acids, flavonols and other groups of phenolic compounds. The ultra-performance liquid chromatography (UPLC) analysis of the phenolic compounds profile revealed that pyrogallol, hesperidin, naringenin and formononetin were higher in hairy roots compared to untransformed roots. The total phenolics, flavonoids content, antioxidant and antimicrobial activity was high in hairy roots compared to untransformed roots. This is the first

  19. Phorate can reverse P450 metabolism-based herbicide resistance in Lolium rigidum.

    PubMed

    Busi, Roberto; Gaines, Todd Adam; Powles, Stephen

    2017-02-01

    Organophosphate insecticides can inhibit specific cytochrome P450 enzymes involved in metabolic herbicide resistance mechanisms, leading to synergistic interactions between the insecticide and the herbicide. In this study we report synergistic versus antagonistic interactions between the organophosphate insecticide phorate and five different herbicides observed in a population of multiple herbicide-resistant Lolium rigidum. Phorate synergised with three different herbicide modes of action, enhancing the activity of the ALS inhibitor chlorsulfuron (60% LD50 reduction), the VLCFAE inhibitor pyroxasulfone (45% LD50 reduction) and the mitosis inhibitor trifluralin (70% LD50 reduction). Conversely, phorate antagonised the two thiocarbamate herbicides prosulfocarb and triallate with a 12-fold LD50 increase. We report the selective reversal of P450-mediated metabolic multiple resistance to chlorsulfuron and trifluralin in the grass weed L. rigidum by synergistic interaction with the insecticide phorate, and discuss the putative mechanistic basis. This research should encourage diversity in herbicide use patterns for weed control as part of a long-term integrated management effort to reduce the risk of selection of metabolism-based multiple herbicide resistance in L. rigidum. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  20. Effects of elevated CO(2) on growth, photosynthesis, elemental composition, antioxidant level, and phytochelatin concentration in Lolium mutiforum and Lolium perenne under Cd stress.

    PubMed

    Jia, Yan; Tang, Shirong; Wang, Ruigang; Ju, Xuehai; Ding, Yongzhen; Tu, Shuxin; Smith, Donald L

    2010-08-15

    The objective of this study was to investigate combined effects of Cd and elevated CO(2) on growth, physiological and physiochemical characteristics, elemental compositions in Lolium mutiforum and Lolium perenne grown in soils amended with three Cd concentrations (0, 25, 100 mg kg(-1)) under two CO(2) levels (375, 810 microLL(-1)). Elevated CO(2) increased net assimilation rate and internal CO(2) concentration, and consequently increased total plant biomass by 51 to 31%. At same spiked Cd level, malondialdehyde content in leaves was lower under elevated than under ambient CO(2), whereas superoxide dismutase activity was higher. Elevated CO(2) decreased Cd, S, and phytochelatin concentrations in roots and shoots to a various degree, depending on plant species and element, but the PC-Cd ratio was not affected. It was concluded that elevated CO(2) ameliorated Cd toxicity in both Lolium species under Cd stress, and that the increase of plant biomass and the alleviation of Cd toxicity with elevated CO(2) for the Lolium species may be more dependent on increased photosynthesis and enhanced antioxidant capacity. Results of the study may provide insights into the interaction between soil Cd contamination and atmospheric CO(2) concentration with regard to plant ability to grow and remove the Cd from soils. Copyright 2010 Elsevier B.V. All rights reserved.

  1. Interchangeable effects of gibberellic acid and temperature on embryo growth, seed germination and epicotyl emergence in Ribes multiflorum ssp. sandalioticum (Grossulariaceae).

    PubMed

    Mattana, E; Pritchard, H W; Porceddu, M; Stuppy, W H; Bacchetta, G

    2012-01-01

    Morphophysiological dormancy was investigated in seeds of Ribes multiflorum Kit ex Roem et Schult. ssp. sandalioticum Arrigoni, a rare mountain species endemic to Sardinia (Italy). There were no differences in imbibition rates between intact and scarified seeds, suggesting a lack of physical dormancy, while methylene blue solution (0.5%) highlighted a preferential pathway for solution entrance through the raphe. Embryos were small at seed dispersal, with an initial embryo:seed ratio (E:S) of ca. 0.2 (embryo length, ca. 0.5 mm), whereas the critical E:S ratio for germination was three times longer (ca. 0.6). Gibberellic acid (GA(3), 250 mg · l(-1)) and warm stratification (25 °C for 3 months) followed by low temperature (<15 °C) enhanced embryo growth rate (maximum of ca. 0.04 mm · day(-1) at 10 °C) and subsequent seed germination (radicle emergence; ca. 80% at 10 °C). Low germination occurred at warmer temperatures, and cold stratification (5 °C for 3 months) induced secondary dormancy. After radicle emergence, epicotyl emergence was delayed for ca. 2 months for seeds from three different populations. Mean time of epicotyl emergence was affected by GA(3) . Seeds of this species showed non-deep simple (root) - non-deep simple (epicotyl) morphophysiological dormancy, highlighting a high synchronisation with Mediterranean seasonality in all the investigated populations. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  2. Lolium perenne as a biomonitor of atmospheric levels of fluoride.

    PubMed

    Rey-Asensio, A; Carballeira, A

    2007-05-01

    The aim of the present study was to develop a standardised protocol for the use of Lolium perenne cultures to biomonitor the surroundings of an aluminium smelter. Five ecological stations, which corresponded to air quality network monitoring sites pertaining to the smelter, were selected for study. Cultures of L. perenne (one at each site) were exposed for approximately 28 days, at different times between August 1999 and October 2000. At the end of the exposure periods, the fluoride concentrations in the cultures were determined. The concentrations of fluoride determined in the L. perenne cultures varied from 4.32 microg g(-1) to 912.22 microg g(-1) and followed a similar trend to concentrations of atmospheric fluoride. However, a wider range of fluoride concentration was observed in the L. perenne cultures than in the air surrounding the smelter. The background levels of fluoride in L. perenne cultures were also calculated, thereby allowing classification of fluoride air pollution in the area under study.

  3. Light and nitrogen competition limit Lolium perenne in experimental grasslands of increasing plant diversity.

    PubMed

    Roscher, C; Kutsch, W L; Schulze, E-D

    2011-01-01

    Positive species richness effects on aboveground community productivity in experimental grasslands have been reported to correlate with variable responses of individual species. So far, it is largely unknown whether more complete use of resources at the community level correlates with resource limitation of particular species and may explain their decreasing performance with increasing plant diversity. Using the subordinate grass species Lolium perenne L. as a model, we monitored populations in 82 experimental grasslands of different plant diversity (Jena Experiment) from year 2 to 6 after establishment, and measured ecophysiological leaf traits related to light and nutrient acquisition and use. Population and plant individual sizes of L. perenne decreased with increasing species richness. A decrease in transmitted light with increasing species richness and legume proportion correlated with increasing specific leaf area (SLA). Despite this morphological adaptation to lower light availability, decreasing foliar δ(13) C signatures with increasing species richness and low variation in leaf gas exchange and chlorophyll concentrations suggested a low capacity of L. perenne for adjustment to canopy shade. Leaf nitrogen concentrations and foliar δ(15) N signatures indicated a better N supply in communities with legumes and a shift in the uptake of different N forms with increasing species richness. Leaf blade nitrate and carbohydrate concentrations as indicators of plants nutritional status supported that light limitation with increasing species richness and legume proportions, combined with a N limitation in communities with increasing proportions of non-legumes, correlated with the decreasing performance of L. perenne in communities of increasing plant diversity. © 2010 German Botanical Society and The Royal Botanical Society of the Netherlands.

  4. Polygonum multiflorum root extract as a potential candidate for treatment of early graying hair

    PubMed Central

    Thang, Nguyen Dinh; Diep, Pham Ngoc; Lien, Pham Thi Huong; Lien, Le Thi

    2017-01-01

    Despite Polygonum multiflorum (PM) has been experiencely used as a drug to treat early graying hair phenomenon in Asian countries for a long time, there is limited study examined the real biological effects of PM on hair graying in vitro and in vivo. In this study, we investigated the effects of PM root extract (PM-RE) on melanin synthesis in human melanoma SKMEL-28 cells and embryos/larvae of wild-type strain AB zebrafish. We also preliminary revealed the molecular mechanism of early hair graying phenomenon in both in vitro and in vivo models. Our results showed that PM-RE significantly induced melanin synthesis in melanin-producing SKMEL-28 melanoma cells and also in zebrafish embryos/larvae at 4-day postfertilization through activation of MC1R/MITF/tyrosinase-signaling pathway. We also investigated the differences in genotype between graying hair follicle and black hair follicle of young peoples and found that early hair graying phenomenon may be related to downregulation of MC1R/MITF/tyrosinase pathway. Taken together, we suggested that PM-RE at safe doses could be used as a potential agent for the treatment of early hair graying and other loss pigmentation-related diseases. PMID:28217548

  5. A New Strategy for Quality Evaluation and Identification of Representative Chemical Components in Polygonum multiflorum Thunb.

    PubMed Central

    Gong, Xiao-hong; Liu, Mei-chen

    2017-01-01

    Polygonum multiflorum Thunb. (HSW) is widely used as herb medicine and health food additive. Recently, a series of HSW-induced hepatotoxicities have been reported and many studies have been carried out to investigate it. But contradictory conclusions were drawn that might be caused by the inconsistent quality of market decoction pieces. Therefore, the HSW decoction pieces quality was evaluated with a developed novel method in the paper. 25 batches of raw HSW (RHSW) and 21 batches of processed HSW (PHSW) samples were purchased from different provinces of China. HPLC determination was performed to identify and detect the contents of 16 chemical compounds in herbal material. Fingerprint similarity was analyzed using chromatography information and the results showed that most herbs were in good similarity. Then, a comprehensive evaluation strategy based on principal component analysis with representative quality control indicators was developed to evaluate the quality of HSW samples. And the rationality of the developed method was verified by HCA analysis. The results showed that the herb from Dabashan, Sichuan Province, no matter RHSW or PHSW had the best quality. Different representative components were selected for RHSW or PHSW decoction pieces which might be caused by the chemical reaction during processing. And most PHSW were unqualified according to the requirement of Chinese Pharmacopeia which might take the responsibility for the toxicity of HSW. PMID:28243311

  6. Effects of Hot Water Extracts from Polygonum multiflorum on Ovariectomy Induced Osteopenia in Mice

    PubMed Central

    Hwang, Yun-Ho; Kang, Kyung-Yun; Kim, Jong-Jin; Lee, Sung-Ju; Son, Young-Jin

    2016-01-01

    Polygonum multiflorum (PM), a traditional Chinese medicine, is used to treat various diseases including nonalcoholic fatty liver disease and hyperlipidemia. However, the influence of PM on osteoporosis in animals is unclear. The present study investigated the antiosteoporotic effect of PM on bone mass in ovariectomized (OVX) mice and its possible mechanism of action. Twenty-five female C3H/HeN mice were divided into five groups of five mice as follows. Sham-operated control mice received daily oral gavage of an equal volume of water, and OVX mice received daily oral gavage of water or an injection of β-estradiol or PM for 6 weeks. Administration of PM significantly suppressed body weight and organs weight and increased weight and length of bone compared with the OVX group. Treatment with PM reversed osteopenia in OVX mice, thereby improving the bone morphometric parameters. Moreover, histological analysis using hematoxylin and eosin staining showed that PM inhibited OVX-induced bone loss. Serum estradiol and bone alkaline phosphatase levels were significantly decreased in the OVX group, with the levels increasing with PM treatment. In addition, tartrate-resistant acid phosphatase activity was inhibited by PM in OVX mice. These results suggest that PM is effective in preventing bone loss in OVX mice. PMID:27746822

  7. Monoterpenes with antibacterial activities from a Cameroonian medicinal plant Canthium Multiflorum (Rubiaceae).

    PubMed

    Kouam, Simeon Fogue; Ngouonpe, Alain Wembe; Bullach, Anke; Lamshöft, Marc; Kuigoua, Guy Merlin; Spiteller, Michael

    2013-12-01

    Investigation of the crude extract obtained from the aerial parts of Canthium multiflorum led to the isolation of a new iridoid (1) together with twelve known compounds. The structures of these compounds were elucidated by interpretation of 1D and 2D NMR spectroscopic data, accurate mass measurements and comparison with analytical data of previously known analogues. Most of the isolated compounds have been reported for the first time from C. multiflorium. The antimicrobial activities of the isolated compounds were evaluated on five different bacterial strains using agar diffusion technique. The Gram-positive bacterium Staphylococcus aureus subsp. aureus (DSM 799), and the Gram-negative bacteria Actinobacter calco-aceticus (DSM 30006), Serratia plymuthica (DSM 4540), Pseudomonas stutzeri (DSM 4166) and Escherichia coli (DSM 1116) were employed for this purpose. The new iridoid, named 6-oxo-genipin (1), demonstrated significant inhibitory activity against all microbial strains tested, especially the pathogen Staphylococcus aureus. In addition, the compounds 3, 4 and 9 exhibited antiplasmodial activity against Plasmodium falciparum strain K1 and weak cytotoxicity against L6 cell lines. © 2013 Elsevier B.V. All rights reserved.

  8. [Harmful elements removal from Polygonum multiflorum by supercritical CO2 extraction].

    PubMed

    Wen, Zhen; Liu, Bo; Zheng, Zong-Kun; You, Xin-Kui; Pu, Yi-Tao; Dang, Zhi

    2008-10-01

    To remove harmful elements as copper, lead and arsenic from Polygonum multiflorum, a Chinese traditional medicine, by supercritical carbon dioxide extraction. With sodium diethyldithiocarbamate (NaDDC) as a chelating agent and ethanol as a modifier, the effects of extraction style, time, pressure, temperature and amount of chelating agent on chelating extraction process were discussed. The condition was optimized as following: 28 MP as extraction pressure, 60 degrees C as extraction temperature, 1 h as static extraction time, 2 h as dynamic extraction time, m(herb) : m(NaDDC) = 5 : 1, m(herb) : m(ethanol) = 1 : 1. Under this condition, the extraction rate of Cu, Pb and As were up to 60% which achieved US FDA standard, while the physioloically active substance of 2,3,5,4'-tetrahydroxy-silbene-2-O-beta-D-glucoside was not extracted. The results show chelating extraction by supercritical CO2 can provide a non-destructive method to decrease the content of harmful elements from Chinese traditional medicines.

  9. Acute hepatitis due to shen-min: a herbal product derived from Polygonum multiflorum.

    PubMed

    Cárdenas, Andrés; Restrepo, Juan Carlos; Sierra, Fernando; Correa, Gonzalo

    2006-08-01

    Shen-Min is a herbal product sold as a supplement for women to enhance hair growth. It is widely available across Asia, Europe, and the United States and sold without prescription as a hair nutritional supplement. We describe a case of acute liver injury in a 28-year-old white woman who developed symptomatic hepatitis 8 weeks after starting Shen-Min. All other potential causes of acute hepatitis including viral, hypoxic/ischemic, metabolic, and autoimmune etiologies were excluded. The liver injury slowly resolved over 3 weeks after discontinuing the herbal product. Although the mechanism of Shen-Min hepatotoxicity is unknown, we suspect an idiosyncratic reaction because the patient developed a fine maculopapular rash, mild eosinophilia, and did not overdose. Shen-Min is a Chinese herbal product with a mixture of several plants and vitamins including Polygonum multiflorum, a root that has been previously associated with hepatotoxicity. Nonetheless to our knowledge this is the first reported case of herbal-induced hepatotoxicity in a patient taking Shen-Min per se. Clinicians taking care of patients with acute hepatitis of unclear etiology should be aware that the consumption of Shen-Min, a hair supplement widely available in the United States and Western countries might cause acute hepatitis.

  10. Cross-resistance to herbicides in annual ryegrass (lolium rigidum)

    SciTech Connect

    Christopher, J.T.; Powles, S.B.; Liljegren, D.R.; Holtum, J.A.M. )

    1991-04-01

    Lolium rigidum Gaud. biotype SLR31 is resistant to the herbicide diclofop-methyl and cross-resistant to several sulfonylurea herbicides. Wheat and the cross-resistant ryegrass exhibit similar patterns of resistance to sulfonylurea herbicides, suggesting that the mechanism of resistance may be similar. Cross-resistant ryegrass is also resistant to the wheat-selective imidazolinone herbicide imazamethabenz. The cross-resistant biotype SLR31 metabolized (phenyl-U-{sup 14}C)chlorsulfuron at a faster rate than a biotype which is susceptible to both diclofop-methyl and chlorsulfuron. A third biotype which is resistant to diclofop-methyl but not to chlorsulfuron metabolized chlorsulfuron at the same rate as the susceptible biotype. The increased metabolism of chlorsulfuron observed in the cross-resistant biotype is, therefore, correlated with the patterns of resistance observed in these L. rigidum biotypes. During high performance liquid chromatography analysis the major metabolite of chlorsulfuron in both susceptible and cross-resistant ryegrass coeluted with the major metabolite produced in wheat. The major product is clearly different from the major product in the tolerant dicot species, flax (Linium usitatissimum). The elution pattern of metabolites of chlorsulfuron was the same for both the susceptible and cross-resistant ryegrass but the cross-resistant ryegrass metabolized chlorsulfuron more rapidly. The investigation of the dose response to sulfonylurea herbicides at the whole plant level and the study of the metabolism of chlorsulfuron provide two independent sets of data which both suggest that the resistance to chlorsulfuron in cross-resistant ryegrass biotype SLR31 involves a wheat-like detoxification system.

  11. Impact of no-till cover cropping of Italian ryegrass on above and below ground faunal communities inhabiting a soybean field with special emphasis on soybean cyst nematodes

    USDA-ARS?s Scientific Manuscript database

    Two field trials were conducted in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop in a no-till soybean (Glycine max) planting to 1) reduce populations of plant-parasitic nematodes (i.e., the soybean cyst nematode, Heterodera glycines and lesion nematodes...

  12. Profiling of phenolic constituents in Polygonum multiflorum Thunb. by combination of ultra-high-pressure liquid chromatography with linear ion trap-Orbitrap mass spectrometry.

    PubMed

    Qiu, Xiaohui; Zhang, Jing; Huang, Zhihai; Zhu, Dayuan; Xu, Wen

    2013-05-31

    A simple and effective method was developed for characterization of phenolic constituents in the roots of Polygonum multiflorum by combination of ultra-high-pressure liquid chromatography with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap). Stilbenes, anthraquinones, tannins and naphthalenes were differentiated by diagnostic fragment ions with accurate mass measurements and characteristic fragmentation pathways. Based on the proposed strategy, fifty-nine constituents were characterized or tentatively identified, of which twenty-two constituents were the first to be reported in P. multiflorum and twelve compounds were characterized as potential new compounds. The identification and structure elucidation of these chemicals provided essential data for further phytochemical studies and quality control of P. multiflorum. The results also demonstrated that our novel method can be extended to screen and characterize other phenolic constituents and their metabolites in botanical extracts.

  13. Enhanced Production of Anthraquinones and Phenolic Compounds and Biological Activities in the Cell Suspension Cultures of Polygonum multiflorum

    PubMed Central

    Thiruvengadam, Muthu; Rekha, Kaliyaperumal; Rajakumar, Govindasamy; Lee, Taek-Jun; Kim, Seung-Hyun; Chung, Ill-Min

    2016-01-01

    Anthraquinones (AQs) and phenolic compounds are important phytochemicals that are biosynthesized in cell suspension cultures of Polygonum multiflorum. We wanted to optimize the effects of plant growth regulators (PGRs), media, sucrose, l-glutamine, jasmonic acid (JA), and salicylic acid (SA) for the production of phytochemicals and biomass accumulation in a cell suspension culture of P. multiflorum. The medium containing Murashige and Skoog (MS) salts and 4% sucrose supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid, 0.5 mg/L thidiazuron, and 100 µM l-glutamine at 28 days of cell suspension culture was suitable for biomass accumulation and AQ production. Maximum biomass accumulation (12.5 and 12.35 g fresh mass (FM); 3 and 2.93 g dry mass (DM)) and AQ production (emodin 295.20 and 282 mg/g DM; physcion 421.55 and 410.25 mg/g DM) were observed using 100 µM JA and SA, respectively. JA- and SA-elicited cell cultures showed several-fold higher biomass accumulation and AQ production than the control cell cultures. Furthermore, the cell suspension cultures effectively produced 23 phenolic compounds, such as flavonols and hydroxycinnamic and hydroxybenzoic acid derivatives. PGR-, JA-, and SA-elicited cell cultures produced a higher amount of AQs and phenolic compounds. Because of these metabolic changes, the antioxidant, antimicrobial, and anticancer activities were high in the PGR-, JA-, and SA-elicited cell cultures. The results showed that the elicitors (JA and SA) induced the enhancement of biomass accumulation and phytochemical (AQs and phenolic compounds) production as well as biological activities in the cell suspension cultures of P. multiflorum. This optimized protocol can be developed for large-scale biomass accumulation and production of phytochemicals (AQs and phenolic compounds) from cell suspension cultures, and the phytochemicals can be used for various biological activities. PMID:27854330

  14. Enhanced Production of Anthraquinones and Phenolic Compounds and Biological Activities in the Cell Suspension Cultures of Polygonum multiflorum.

    PubMed

    Thiruvengadam, Muthu; Rekha, Kaliyaperumal; Rajakumar, Govindasamy; Lee, Taek-Jun; Kim, Seung-Hyun; Chung, Ill-Min

    2016-11-16

    Anthraquinones (AQs) and phenolic compounds are important phytochemicals that are biosynthesized in cell suspension cultures of Polygonum multiflorum. We wanted to optimize the effects of plant growth regulators (PGRs), media, sucrose, l-glutamine, jasmonic acid (JA), and salicylic acid (SA) for the production of phytochemicals and biomass accumulation in a cell suspension culture of P. multiflorum. The medium containing Murashige and Skoog (MS) salts and 4% sucrose supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid, 0.5 mg/L thidiazuron, and 100 µM l-glutamine at 28 days of cell suspension culture was suitable for biomass accumulation and AQ production. Maximum biomass accumulation (12.5 and 12.35 g fresh mass (FM); 3 and 2.93 g dry mass (DM)) and AQ production (emodin 295.20 and 282 mg/g DM; physcion 421.55 and 410.25 mg/g DM) were observed using 100 µM JA and SA, respectively. JA- and SA-elicited cell cultures showed several-fold higher biomass accumulation and AQ production than the control cell cultures. Furthermore, the cell suspension cultures effectively produced 23 phenolic compounds, such as flavonols and hydroxycinnamic and hydroxybenzoic acid derivatives. PGR-, JA-, and SA-elicited cell cultures produced a higher amount of AQs and phenolic compounds. Because of these metabolic changes, the antioxidant, antimicrobial, and anticancer activities were high in the PGR-, JA-, and SA-elicited cell cultures. The results showed that the elicitors (JA and SA) induced the enhancement of biomass accumulation and phytochemical (AQs and phenolic compounds) production as well as biological activities in the cell suspension cultures of P. multiflorum. This optimized protocol can be developed for large-scale biomass accumulation and production of phytochemicals (AQs and phenolic compounds) from cell suspension cultures, and the phytochemicals can be used for various biological activities.

  15. Lolium latent virus (Alphaflexiviridae) coat proteins: expression and functions in infected plant tissue

    USDA-ARS?s Scientific Manuscript database

    The Lolium latent virus (LoLV, Lolavirus, Alphaflexiviridae) viral genome is encapsidated by two carboxy-coterminal coat protein (CP) variants (about 28 and 33 kDa), in equimolar proportion. The CP ORF contains two 5'-proximal AUGs, encoding Met 1 and Met 49, respectively promoting translation of th...

  16. Genotype _ environment interactions for forage yield of Lolium perenne L. sward plots in Ireland

    USDA-ARS?s Scientific Manuscript database

    Lolium perenne L. (perennial ryegrass) is by far the most widely sown grass species in Ireland. Genotype by environment (G by E) interactions are a frequent occurrence in forage yield evaluations. The objectives were to determine (i) the nature and relative magnitudes of the pertinent G by E interac...

  17. Transcriptome response of Lolium arundinaceum to the fungal endophyte Epichloe coenophiala

    USDA-ARS?s Scientific Manuscript database

    Tall fescue (Lolium arundinaceum) is one of the principal cool-season species used as a forage and turf within the USA. A number of benefits associated with the persistence of tall fescue have been attributed to the presence of its seed-transmissible symbiont, the fungal endophyte Epichloë coenophi...

  18. Transcriptome response in different tissues of Lolium arundinaceum to the fungal endophyte Epichloe coenophiala

    USDA-ARS?s Scientific Manuscript database

    Tall fescue (Lolium arundinaceum) plants symbiotic with the endophytic fungus, Epichloe coenophiala , (E+), have been shown to have better survivability and persistence than plants lacking the endophyte (E-). To understand more about the grass-endophyte interactions and how endophyte affects the ho...

  19. Abiotic stresses activate a MAPkinase in the model grass species Lolium temulentum L.

    USDA-ARS?s Scientific Manuscript database

    Forage and turf grasses are utilized in diverse environments which exposes them to a variety of abiotic stresses, however very little is known concerning the perception or molecular responses to these various stresses. In the model grass species Lolium temulentum (Lt), a 46 kDa mitogen-activated pro...

  20. Effects of Jasminum multiflorum leaf extract on rodent models of epilepsy, motor coordination and anxiety.

    PubMed

    Addae, Jonas I; Pingal, Ramish; Walkins, Kheston; Cruickshank, Renee; Youssef, Farid F; Nayak, Shivananda B

    2017-03-01

    Jasmine flowers and leaves are used extensively in folk medicine in different parts of the world to treat a variety of diseases. However, there are very few published reports on the neuropsychiatric effects of Jasmine extracts. Hence, the objectives of the present study were to examine the effects of an alcohol extract of Jasminum multiflorum leaves on topically-applied bicuculline (a model of acute simple partial epilepsy) and maximal electroshock (MES, a model of generalized tonic-clonic seizure) in male Sprague-Dawley rats. The objectives also included an examination of the anxiolytic properties of the extract using an elevated plus maze and the effect of the extract on motor coordination using a rotarod treadmill. Phytochemical analysis of the extract showed the presence of three flavonoids and four additional compounds belonging to the steroid, terpenoid, phenol or sugar classes of compounds. The Jasmine alcohol extract, diluted with water and given orally or intraperitoneally, reduced the number of bicuculline-induced epileptiform discharges in a dose-dependent manner. The extract did not cause a significant increase in the current needed to induce hind limb extension in MES experiments. The extract significantly affected motor coordination when injected at 500mg/kg but not at 200mg/kg. At the latter dose, the extract increased open-arm entries and duration in the elevated plus maze to a level comparable to that of diazepam at 2mg/kg. We conclude that Jasmine leaf extract has a beneficial effect against an animal model of acute partial complex epilepsy, and significant anxiolytic effect at a dose that does not affect motor co-ordination. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Structural, physicochemical, antioxidant and antitumor property of an acidic polysaccharide from Polygonum multiflorum.

    PubMed

    Zhu, Weili; Xue, Xiaoping; Zhang, Zhanjun

    2017-03-01

    In this study, the structural characterization, physicochemical property, antioxidant and antitumor activity of an acidic polysaccharide (APS) from Polygonum multiflorum were investigated. Monosaccharide composition analysis showed APS was composed of arabinose, rhamnose, galactose and galacturonic acid in the molar ratio of 1.23:1.32:1.48:1.00. The presence of uronic acid was also confirmed by the bands at 1740, 1645 and 1425cm(-1) on Fourier transform-infrared spectroscopy. Methylation and nuclear magnetic resonance analyses showed APS was mainly composed by the residues of →5)-α-l-Araf-(1→, →3)-β-d-Galp-(1→, →3,6)-β-d-Galp-(1→, →4)-α-d-GalAp-(1→ and →2)-α-l-Rhap-(1→ in the backbone. The non-reducing terminal α-l-Araf-(1→ was probably attached to the O-6 position of →3,6)-β-d-Galp-(1→ residues. Besides, APS exhibited rod-like and flaky shapes with rough surface. The initial decomposition of APS occurred at 172°C, and the rapidest weight loss rate of APS appeared at 320°C. Antioxidant activity assay showed the DPPH radical scavenging activity of APS was 67.5% at 1mg/mL. At the concentration of 400μg/mL, the antiproliferation activities of APS against HepG-2 and BGC-823 cells were 65.28% and 51.57%, respectively. Our results suggested APS could be a potential antioxidant and antitumor agent.

  2. Intensive cropping systems select for greater seed dormancy and increased herbicide resistance levels in Lolium rigidum (annual ryegrass).

    PubMed

    Owen, Mechelle J; Goggin, Danica E; Powles, Stephen B

    2015-07-01

    Lolium rigidum (annual ryegrass) is a widespread annual crop weed that has evolved high levels of resistance to selective herbicides. Anecdotal evidence suggests that intensive cropping also leads to higher seed dormancy in L. rigidum. This was quantified by measuring dormancy levels in L. rigidum populations collected from paired sites (one with nil to low cropping intensity, the other intensively cropped) located throughout the Western Australian grain belt. Populations from non-cropped fields or those with low cropping intensity showed higher and faster germination than populations from fields with a medium- or high-intensity cropping regime. Resistance to selective herbicides was also higher in the medium- and high-intensity cropping fields than in the low-intensity cropping fields. High-intensity cropping systems are likely to impose greater selection pressures for seed dormancy and selective herbicide resistance, because late-emerging seedlings avoid preplanting weed control practices (tillage and non-selective herbicide application) but are exposed to selective in-crop herbicides. © 2014 Society of Chemical Industry.

  3. Cross-resistance to prosulfocarb + S-metolachlor and pyroxasulfone selected by either herbicide in Lolium rigidum.

    PubMed

    Busi, Roberto; Powles, Stephen B

    2016-09-01

    Weeds can be a greater constraint to crop production than animal pests and pathogens. Pre-emergence herbicides are crucial in many cropping systems to control weeds that have evolved resistance to selective post-emergence herbicides. In this study we assessed the potential to evolve resistance to the pre-emergence herbicides prosulfocarb + S-metolachlor or pyroxasulfone in 50 individual field Lolium rigidum populations collected in a random survey in Western Australia prior to commercialisation of these pre-emergence herbicides. This study shows for the first time that in randomly collected L. rigidum field populations the selection with either prosulfocarb + S-metolachlor or pyroxasulfone can result in concomitant evolution of resistance to both prosulfocarb + S-metolachlor and pyroxasulfone after three generations. In the major weed L. rigidum, traits conferring resistance to new herbicides can be present before herbicide commercialisation. Proactive and multidisciplinary research (evolutionary ecology, modelling and molecular biology) is required to detect and analyse resistant populations before they can appear in the field. Several studies show that evolved cross-resistance in weeds is complex and often unpredictable. Thus, long-term management of cross-resistant weeds must be achieved through heterogeneity of selection by effective chemical, cultural and physical weed control strategies that can delay herbicide resistance evolution. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. Host genotype overrides fungal endophyte infection in influencing tiller and spike production of Lolium perenne (Poaceae) in a common garden experiment.

    PubMed

    Cheplick, Gregory P

    2008-09-01

    Leaves of many cool-season grasses are infected by endophytic fungi that can impact their populations. A common garden experiment with Lolium perenne was established in a lawn in New Jersey, USA, to investigate the impact of endophyte infection and host genotype on tiller and spike production over three years. Infected (E+) and uninfected (E-) plants of each genotype were monitored every 2-3 mo. Infection intensity within plants varied significantly among genotypes and years, but there was no evidence of directional change over time. Tiller production varied significantly among genotypes and was affected by endophytes: E+ plants of several genotypes produced more tillers than E- plants during the third year. E+ plants had greater aboveground biomass, but host genotype explained a far greater proportion of variation in tiller production, number, and biomass than infection. Plant survival, percentage flowering, flowering date, number of spikes, and mean tiller mass were unaffected by endophytes. However, the last three variables showed significant variation among host genotypes. Although studies have demonstrated a positive growth effect of endophytes on several grass hosts, in this experiment host genotype accounted for far more of the variation in tiller and spike production and in biomass of Lolium perenne than endophyte infection.

  5. Silage from maize (Zea mays), annual ryegrass (Lolium multiflorum) or their mixture in the dry season feeding of grazing dairy cows in small-scale dairy production systems in the highlands of Mexico.

    PubMed

    Anaya-Ortega, J P; Garduño-Castro, G; Espinoza-Ortega, A; Rojo-Rubio, R; Arriaga-Jordán, C M

    2009-04-01

    Small-scale dairy systems based on grazing have dry-season herbage shortages. A repeated 3 x 3 Latin Square experiment evaluated grazing with silage from maize (MS), annual ryegrass (ARG) or a mixture (MIX) with 9 cows with 3 week periods; continuously grazed at 3.6 cows/ha with 3.6 kg DM/day of concentrate. Treatments were 7 kg DM of MS, ARG or a 2 MS:1 ARG mixture. Milk yield (MY), milk composition, live-weight, body condition, silage and concentrate intake were recorded. Herbage DM intake was estimated indirectly. Activity budgets were done for economic analysis. MY on MS (21.5 kg/cow/d) was 0.06 higher than on ARG (P < 0.09) with no differences on MIX. There were no differences for milk fat, milk protein, or body condition score. Live-weight on ARG was higher (P < 0.01) than on MS or MIX. Silage intake was higher (P < 0.01) on ARG and MS than on MIX. Herbage intake was lower (P < 0.05) on MS, compared with MIX and ARG. Total DM intake on ARG was higher than MS (P < 0.01), and MIX in between. MS resulted in 0.12 higher economic returns over ARG which had highest costs. Annual ryegrass may have a place in small-scale systems, but not as silage due to higher costs.

  6. Preventive effects of Polygonum multiflorum on glucocorticoid-induced osteoporosis in rats.

    PubMed

    Zhou, Manru; Li, Jin; Wu, Jingkai; Yang, Yajun; Zeng, Xiaobing; Lv, Xiaohua; Cui, Liao; Yao, Weimin; Liu, Yuyu

    2017-09-01

    In Traditional Chinese Medicine, Polygonum multiflorum (PM) is known for its anti-aging properties. A previous study by our group showed that extracts of PM were able to prevent and treat bone loss in vivo, and the active components emodin and 2,3,5,4,-tetrahydroxystilbene-2-O-β-glucoside (TSG) promoted the osteogenic differentiation of mesenchymal stem cells in vitro. The aim of the present study was to investigate the preventive effects of PM on glucocorticoid-induced osteoporosis (GIO) in rats. A crude extract of PM was prepared with 75% ethanol, purified and enriched using a D-101 macroresin column and elution with 30% ethanol, and the material obtained was assessed by high-performance liquid chromatography. Male or female Sprague Dawley rats (n=180) were randomly divided into nine groups: Control, prednisone, prednisone plus calcitriol (CAL), prednisone plus 30% ethanolic eluate of PM [high (H), medium (M) and low (L) dose] and prednisone plus crude extract of PM (H, M and L dose). Prednisone was orally administered to the osteoporosis model rats for 21 weeks, alongside which they received PM extracts. The weight of the viscera, anterior tibial muscle and other tissues was recorded at the end of the experiment. The femur and lumbar vertebra were collected for the measurement of three-dimensional microarchitecture by micro-computed tomography scanning, assessment of biomechanical properties and determination of bone mineral density (BMD). In the 30% ethanolic eluate of the PM extract, the content of TSG and combined anthraquinone was 9.20 and 0.15%, respectively, and that in the crude extract of PM was 2.23 and 0.03%, respectively. Over 6 weeks, the weight of the rats the in prednisone group decreased (P<0.05), while the weight of rats treated with M and H doses of 30% ethanolic eluate was increased compared with that in the prednisone group (P<0.05). Rats exposed to prednisone exhibited a deteriorated bone microarchitecture, low BMD, decreased bone volume

  7. Optimal inductive and cultural conditions of Polygonum multiflorum transgenic hairy roots mediated with Agrobacterium rhizogenes R1601 and an analysis of their anthraquinone constituents

    PubMed Central

    Huang, Bing; Lin, Huanjie; Yan, Chuanyan; Qiu, Hongyan; Qiu, Lipeng; Yu, Rongmin

    2014-01-01

    Background: Polygonum multiflorum is an important medicinal plant. Hairy roots systems obtained by transforming plant tissues with the natural genetic engineer Agrobacterium rhizogenes can produce valuable biological active substances, which have immense potential in the pharmaceutical industry. Objective: To optimize the inductive and cultural conditions of P. multiflorum hairy roots and to identify the major active secondary metabolites in hairy roots. Materials and Methods: P. multiflorum hairy root were mediated with A. rhizogenes R1601 to induce hairy roots. Four combinations, including Murashige–Skoog (MS), 1/2 MS, B5, and White, were investigated to optimize the culture medium. MS medium was selected for the growth measurement. The qualitative and quantitative determinations of free anthraquinone in hairy roots were compared with the calli and aseptic plantlets using high-performance liquid chromatography. Results: The inductive rates of hairy roots by leaves were higher than for any other explants. The presence of agropine in the P. multiflorum hairy roots confirmed that they were indeed transgenic. MS medium was the most suitable of the four media for hairy root growth. Meanwhile, the growth kinetics and nutrient consumption results showed that the hairy roots displayed a sigmoidal growth curve and that their optimal inoculation time was 18-21 days. The determination of the anthraquinone constituents indicated that the rhein content of the hairy roots reached 2.495 μg g−1 and was 2.55-fold higher than that of natural plants. Conclusion: Transgenic hairy roots of P. multiflorum could be one of the most potent materials for industrial-scale production of bioactive anthraquinone constituents. PMID:24696550

  8. Herbicide Safeners Decrease Sensitivity to Herbicides Inhibiting Acetolactate-Synthase and Likely Activate Non-Target-Site-Based Resistance Pathways in the Major Grass Weed Lolium sp. (Rye-Grass).

    PubMed

    Duhoux, Arnaud; Pernin, Fanny; Desserre, Diane; Délye, Christophe

    2017-01-01

    Herbicides are currently pivotal to control weeds and sustain food security. Herbicides must efficiently kill weeds while being as harmless as possible for crops, even crops taxonomically close to weeds. To increase their selectivity toward crops, some herbicides are sprayed in association with safeners that are bioactive compounds exacerbating herbicide-degrading pathways reputedly specifically in crops. However, exacerbated herbicide metabolism is also a key mechanism underlying evolved non-target-site-based resistance to herbicides (NTSR) in weeds. This raised the issue of a possible role of safeners on NTSR evolution in weeds. We investigated a possible effect of the respective field rates of the two broadly used safeners cloquintocet-mexyl and mefenpyr-diethyl on the sensitivity of the troublesome global weed Lolium sp. (rye-grass) to the major herbicides inhibiting acetolactate-synthase (ALS) pyroxsulam and iodosulfuron + mesosulfuron, respectively. Three Lolium sp. populations were studied in three series of experiments. The first experiment series compared the frequencies of plants surviving application of each herbicide alone or in association with its safener. Safener co-application caused a net increase ranging from 5.0 to 46.5% in the frequency of plants surviving the field rate of their associated herbicide. In a second series of experiments, safener effect was assessed on individual plant sensitivity using vegetative propagation. A reduction in sensitivity to pyroxsulam and to iodosulfuron + mesosulfuron was observed for 44.4 and 11.1% of the plants in co-treatment with cloquintocet-mexyl and mefenpyr-diethyl, respectively. A third series of experiments investigated safener effect on the expression level of 19 Lolium sp. NTSR marker genes. Safeners showed an enhancing effect on the expression level of 10 genes. Overall, we demonstrated that cloquintocet-mexyl and mefenpyr-diethyl both reduced the sensitivity of Lolium sp. to their associated ALS

  9. Evolved polygenic herbicide resistance in Lolium rigidum by low-dose herbicide selection within standing genetic variation

    PubMed Central

    Busi, Roberto; Neve, Paul; Powles, Stephen

    2013-01-01

    The interaction between environment and genetic traits under selection is the basis of evolution. In this study, we have investigated the genetic basis of herbicide resistance in a highly characterized initially herbicide-susceptible Lolium rigidum population recurrently selected with low (below recommended label) doses of the herbicide diclofop-methyl. We report the variability in herbicide resistance levels observed in F1 families and the segregation of resistance observed in F2 and back-cross (BC) families. The selected herbicide resistance phenotypic trait(s) appear to be under complex polygenic control. The estimation of the effective minimum number of genes (NE), depending on the herbicide dose used, reveals at least three resistance genes had been enriched. A joint scaling test indicates that an additive-dominance model best explains gene interactions in parental, F1, F2 and BC families. The Mendelian study of six F2 and two BC segregating families confirmed involvement of more than one resistance gene. Cross-pollinated L. rigidum under selection at low herbicide dose can rapidly evolve polygenic broad-spectrum herbicide resistance by quantitative accumulation of additive genes of small effect. This can be minimized by using herbicides at the recommended dose which causes high mortality acting outside the normal range of phenotypic variation for herbicide susceptibility. PMID:23798973

  10. Comparative Metabolite Fingerprinting of the Rumen System during Colonisation of Three Forage Grass (Lolium perenne L.) Varieties

    PubMed Central

    Kingston-Smith, Alison H.; Davies, Teri E.; Rees Stevens, Pauline; Mur, Luis A. J.

    2013-01-01

    The rumen microbiota enable ruminants to degrade complex ligno-cellulosic compounds to produce high quality protein for human consumption. However, enteric fermentation by domestic ruminants generates negative by-products: greenhouse gases (methane) and environmental nitrogen pollution. The current lack of cultured isolates representative of the totality of rumen microbial species creates an information gap about the in vivo function of the rumen microbiota and limits our ability to apply predictive biology for improvement of feed for ruminants. In this work we took a whole ecosystem approach to understanding how the metabolism of the microbial population responds to introduction of its substrate. Fourier Transform Infra Red (FTIR) spectroscopy-based metabolite fingerprinting was used to discriminate differences in the plant-microbial interactome of the rumen when using three forage grass varieties (Lolium perenne L. cv AberDart, AberMagic and Premium) as substrates for microbial colonisation and fermentation. Specific examination of spectral regions associated with fatty acids, amides, sugars and alkanes indicated that although the three forages were apparently similar by traditional nutritional analysis, patterns of metabolite flux within the plant-microbial interactome were distinct and plant genotype dependent. Thus, the utilisation pattern of forage nutrients by the rumen microbiota can be influenced by subtleties determined by forage genotypes. These data suggest that our interactomic approach represents an important means to improve forages and ultimately the livestock environment. PMID:24312434

  11. A potential role for endogenous microflora in dormancy release, cytokinin metabolism and the response to fluridone in Lolium rigidum seeds

    PubMed Central

    Goggin, Danica E.; Emery, R. J. Neil; Kurepin, Leonid V.; Powles, Stephen B.

    2015-01-01

    Background and Aims Dormancy in Lolium rigidum (annual ryegrass) seeds can be alleviated by warm stratification in the dark or by application of fluridone, an inhibitor of plant abscisic acid (ABA) biosynthesis via phytoene desaturase. However, germination and absolute ABA concentration are not particularly strongly correlated. The aim of this study was to determine if cytokinins of both plant and bacterial origin are involved in mediating dormancy status and in the response to fluridone. Methods Seeds with normal or greatly decreased (by dry heat pre-treatment) bacterial populations were stratified in the light or dark and in the presence or absence of fluridone in order to modify their dormancy status. Germination was assessed and seed cytokinin concentration and composition were measured in embryo-containing or embryo-free seed portions. Key Results Seeds lacking bacteria were no longer able to lose dormancy in the dark unless supplied with exogenous gibberellin or fluridone. Although these seeds showed a dramatic switch from active cytokinin free bases to O-glucosylated storage forms, the concentrations of individual cytokinin species were only weakly correlated to dormancy status. However, cytokinins of apparently bacterial origin were affected by fluridone and light treatment of the seeds. Conclusions It is probable that resident microflora contribute to dormancy status in L. rigidum seeds via a complex interaction between hormones of both plant and bacterial origin. This interaction needs to be taken into account in studies on endogenous seed hormones or the response of seeds to plant growth regulators. PMID:25471097

  12. Mapping with RAD (restriction-site associated DNA) markers to rapidly identify QTL for stem rust resistance in Lolium perenne.

    PubMed

    Pfender, W F; Saha, M C; Johnson, E A; Slabaugh, M B

    2011-05-01

    A mapping population was created to detect quantitative trait loci (QTL) for resistance to stem rust caused by Puccinia graminis subsp. graminicola in Lolium perenne. A susceptible and a resistant plant were crossed to produce a pseudo-testcross population of 193 F(1) individuals. Markers were produced by the restriction-site associated DNA (RAD) process, which uses massively parallel and multiplexed sequencing of reduced-representation libraries. Additional simple sequence repeat (SSR) and sequence-tagged site (STS) markers were combined with the RAD markers to produce maps for the female (738 cM) and male (721 cM) parents. Stem rust phenotypes (number of pustules per plant) were determined in replicated greenhouse trials by inoculation with a field-collected, genetically heterogeneous population of urediniospores. The F(1) progeny displayed continuous distribution of phenotypes and transgressive segregation. We detected three resistance QTL. The most prominent QTL (qLpPg1) is located near 41 cM on linkage group (LG) 7 with a 2-LOD interval of 8 cM, and accounts for 30-38% of the stem rust phenotypic variance. QTL were detected also on LG1 (qLpPg2) and LG6 (qLpPg3), each accounting for approximately 10% of phenotypic variance. Alleles of loci closely linked to these QTL originated from the resistant parent for qLpPg1 and from both parents for qLpPg2 and qLpPg3. Observed quantitative nature of the resistance may be due to partial-resistance effects against all pathogen genotypes, or qualitative effects completely preventing infection by only some genotypes in the genetically mixed inoculum. RAD markers facilitated rapid construction of new genetic maps in this outcrossing species and will enable development of sequence-based markers linked to stem rust resistance in L. perenne.

  13. Breeding for Bio-ethanol Production in Lolium perenne L.: Association of Allelic Variation with High Water-Soluble Carbohydrate Content.

    PubMed

    Farrar, Kerrie; Bryant, David N; Turner, Lesley; Gallagher, Joe A; Thomas, Ann; Farrell, Markku; Humphreys, Mervyn O; Donnison, Iain S

    Increasing the extractable sugar yield from perennial crops is one strategy to generate renewable fuels such as bio-ethanol. Lolium perenne L. (perennial ryegrass) can contain significant (>30% dry matter) water-soluble sugars in the form of polymeric fructan which is readily extracted, broken down and fermented to bio-ethanol. A population of L. perenne generated from four parents which differed in water-soluble carbohydrate (WSC) content was subjected to multiple rounds of selection and recombination on the basis of early spring WSC content to produce a high WSC, and a low WSC population. A control population was generated by selecting the same number of plants at random. The alleles present at six candidate gene loci were analysed before and after selection and correlated to WSC content. Significant differences in the allele frequency of L. perenne soluble-acid invertase1:4 were observed between the three populations with one haplotype significantly associated with the high WSC C2(S+) population (after three rounds of selection and two rounds of recombination). Moreover, WSC content was also associated with biomass accumulation. Thus, in addition to a 2.84-fold increase in WSC yield, the C2(S+) population also had 1.48-fold more biomass per plant, resulting in 3.9-fold higher WSC yield per plant than the control population.

  14. Comparison of Early Development of Three Grasses: Lolium perenne, Agrostis stolonifera and Poa pratensis

    PubMed Central

    FUSTEC, JOELLE; GUILLEUX, JOELLE; LE CORFF, JOSIANE; MAITRE, JEAN-PAUL

    2005-01-01

    • Background and Aims To improve the management of grass communities, early plant development was compared in three species with contrasting growth forms, a caespitose (Lolium perenne), a rhizomatous (Poa pratensis) and a caespitose–stoloniferous species (Agrostis stolonifera). • Methods Isolated seedlings were grown in a glasshouse without trophic constraints for 37 d (761 °Cd). The appearance of leaves and their location on tillers were recorded. Leaf appearance rate (LAR) on the tillers and site-filling were calculated. Tillering was modelled based on the assumption that tiller number increases with the number of leaves produced on the seedling main stem. Above- and below-ground parts were harvested to compare biomass. • Key Results Lolium perenne and A. stolonifera expressed similar bunch-type developments. However, root biomass was approx. 30 % lower in A. stolonifera than in L. perenne. Poa pratensis was rhizomatous. Nevertheless, the ratio of above-ground : below-ground biomass of P. pratensis was similar to that of L. perenne. LAR was approximately equal to 0·30 leaf d−1 in L. perenne, and on the main stem and first primary tillers of A. stolonifera. LAR on the other tillers of A. stolonifera was 30 % higher than on L. perenne. For P. pratensis, LAR was 30 % lower than on L. perenne, but the interval between the appearance of two successive shoots from rhizomes was 30 % higher than the interval between two successive leaf stages on the main stem. Above-ground parts of P. pratensis first grew slower than in the other species to the benefit of the rhizomes, whose development enhanced tiller production. • Conclusions Lolium perenne had the fastest tiller production at the earliest stages of seedling development. Agrostis stolonifera and P. pratensis compensated almost completely for the delay due to higher LAR on tillers or ramets compared with L. perenne. This study provides a basis for modelling plant development. PMID:15932884

  15. Endophytic fungus decreases plant virus infections in meadow ryegrass (Lolium pratense)

    PubMed Central

    Lehtonen, Päivi T; Helander, Marjo; Siddiqui, Shahid A; Lehto, Kirsi; Saikkonen, Kari

    2006-01-01

    We studied the effects of fungal endophyte infection of meadow ryegrass (Lolium pratense=Festuca pratensis) on the frequency of the barley yellow dwarf virus (BYDV). The virus is transferred by aphids, which may be deterred by endophyte-origin alkaloids within the plant. In our experiment, we released viruliferous aphid vectors on endophyte-infected and endophyte-free plants in a common garden. The number of aphids and the percentage of BYDV infections were lower in endophyte-infected plants compared to endophyte-free plants, indicating that endophyte infection may protect meadow ryegrass from BYDV infections. PMID:17148304

  16. Variation in Alkaloid Production from Genetically Diverse Lolium Accessions Infected with Epichloë Species.

    PubMed

    Moore, Joseph R; Pratley, James E; Mace, Wade J; Weston, Leslie A

    2015-12-09

    Widespread infection of Epichloë occultans in annual ryegrass in Australia suggests that infection provides its weedy host, Lolium rigidum, some ecological advantage. Initial studies determined the distribution and profiles of known Epichloë alkaloids (epoxy-janthitrems, ergovaline, lolines, lolitrem B, and peramine) in plant extracts using a combination of GC-FID and HPLC techniques utilizing a single accession of Australian L. rigidum. However, the lolines N-acetylnorloline (NANL) and N-formylloline (NFL) were the only alkaloids detected and were highly concentrated in the immature inflorescences of mature plants. Additional glasshouse studies subjected a wide range of Australian L. rigidum haplotypes and international annual Lolium accessions to a suite of analyses to determine alkaloid levels and profiles. Again, NFL and NANL were the key lolines produced, with NFL consistently predominating. Considerable variation in alkaloid production was found both within and between biotypes and accessions evaluated under identical conditions, at the same maturation stage and on the same tissue type. The pyrrolopyrazine alkaloid peramine was also present in 8 out of 17 Australian biotypes of L. rigidum and 7 out of 33 international accessions infected with Epichloë spp.; the highest peramine concentrations were observed in seed extracts from L. rigidum collected from Australia. This study represents the first report of alkaloids from a geographically diverse collection of annual ryegrass germplasm infected with Epichloë spp. when grown under identical controlled conditions.

  17. Cloning and characterization of a novel fructan 6-exohydrolase strongly inhibited by sucrose in Lolium perenne.

    PubMed

    Lothier, Jérémy; Van Laere, André; Prud'homme, Marie-Pascale; Van den Ende, Wim; Morvan-Bertrand, Annette

    2014-09-01

    The first 6-fructan exohydrolase (6-FEH) cDNA from Lolium perenne was cloned and characterized. Following defoliation, Lp6 - FEHa transcript level unexpectedly decreased together with an increase in total FEH activity. Lolium perenne is a major forage grass species that accumulates fructans, mainly composed of β(2,6)-linked fructose units. Fructans are mobilized through strongly increased activities of fructan exohydrolases (FEHs), sustaining regrowth following defoliation. To understand the complex regulation of fructan breakdown in defoliated grassland species, the objective was to clone and characterize new FEH genes in L. perenne. To find FEH genes related to refoliation, a defoliated tiller base cDNA library was screened. Characterization of the recombinant protein was performed in Pichia pastoris. In this report, the cloning and enzymatic characterization of the first 6-FEH from L. perenne is described. Following defoliation, during fructan breakdown, Lp6-FEHa transcript level unexpectedly decreased in elongating leaf bases (ELB) and in mature leaf sheaths (tiller base) in parallel to increased total FEH activities. In comparison, transcript levels of genes coding for fructosyltransferases (FTs) involved in fructan biosynthesis also decreased after defoliation but much faster than FEH transcript levels. Since Lp6-FEHa was strongly inhibited by sucrose, mechanisms modulating FEH activities are discussed. It is proposed that differences in the regulation of FEH activity among forage grasses influence their tolerance to defoliation.

  18. Plant vigour at establishment and following defoliation are both associated with responses to drought in perennial ryegrass (Lolium perenne L.)

    PubMed Central

    Hatier, Jean-Hugues B.; Faville, Marty J.; Hickey, Michael J.; Koolaard, John P.; Schmidt, Jana; Carey, Brandi-Lee; Jones, Chris S.

    2014-01-01

    Periodic drought events present a significant and, with climate change, increasing constraint on temperate forage plants’ production. Consequently, improving plants’ adaptive response to abiotic stress is a key goal to ensure agricultural productivity in these regions. In this study we developed a new methodology, using both area-based comparison and soil water content measurements of individual non-irrigated and irrigated clones, to assess performance of perennial ryegrass (Lolium perenne L.) genotypes subjected to moisture stress in a simulated competitive environment. We applied this method to the evaluation of a full-sibling population from a pair cross between genotypes from a New Zealand cultivar and a Moroccan ecotype. Our hypothesis was that: (i) both leaf lamina regrowth after defoliation (LR) and plant vigour affect plant performance during drought and rehydration; and (ii) quantitative trait loci (QTLs) associated with plant performance under moisture stress could be identified. Differences amongst genotypes in dry matter (DM) production, early vigour at establishment, leaf elongation rate and LR were measured. LR explained most of the variation in DM production during exposure to moisture deficit and rehydration followed by plant vigour, indicated by initial DM production in both treatments and subsequent measures of DM production of irrigated clones. We identified two main QTL regions associated with DM production and LR, both during drought exposure and rehydration. Further research focused on these regions should improve our understanding of the genetic control of drought response in this forage crop and potentially other grass species with significant synteny, and support improvement in performance through molecular breeding approaches. PMID:25104762

  19. Plant vigour at establishment and following defoliation are both associated with responses to drought in perennial ryegrass (Lolium perenne L.).

    PubMed

    Hatier, Jean-Hugues B; Faville, Marty J; Hickey, Michael J; Koolaard, John P; Schmidt, Jana; Carey, Brandi-Lee; Jones, Chris S

    2014-11-01

    Periodic drought events present a significant and, with climate change, increasing constraint on temperate forage plants' production. Consequently, improving plants' adaptive response to abiotic stress is a key goal to ensure agricultural productivity in these regions. In this study we developed a new methodology, using both area-based comparison and soil water content measurements of individual non-irrigated and irrigated clones, to assess performance of perennial ryegrass (Lolium perenne L.) genotypes subjected to moisture stress in a simulated competitive environment. We applied this method to the evaluation of a full-sibling population from a pair cross between genotypes from a New Zealand cultivar and a Moroccan ecotype. Our hypothesis was that: (i) both leaf lamina regrowth after defoliation (LR) and plant vigour affect plant performance during drought and rehydration; and (ii) quantitative trait loci (QTLs) associated with plant performance under moisture stress could be identified. Differences amongst genotypes in dry matter (DM) production, early vigour at establishment, leaf elongation rate and LR were measured. LR explained most of the variation in DM production during exposure to moisture deficit and rehydration followed by plant vigour, indicated by initial DM production in both treatments and subsequent measures of DM production of irrigated clones. We identified two main QTL regions associated with DM production and LR, both during drought exposure and rehydration. Further research focused on these regions should improve our understanding of the genetic control of drought response in this forage crop and potentially other grass species with significant synteny, and support improvement in performance through molecular breeding approaches.

  20. Stilbene glucoside from Polygonum multiflorum Thunb.: a novel natural inhibitor of advanced glycation end product formation by trapping of methylglyoxal.

    PubMed

    Lv, Lishuang; Shao, Xi; Wang, Liyan; Huang, Derong; Ho, Chi-Tang; Sang, Shengmin

    2010-02-24

    Methylglyoxal (MGO), the reactive dicarbonyl intermediate generated during the nonenzymatic glycation between reducing sugars and amino groups of proteins, lipids, and DNA, is the precursor of advanced glycation end products (AGEs). Many studies have shown that AGEs play a major pathogenic role in diabetes and its complications. This study found that 2,3,5,4'-tetrahydroxystilbene 2-O-beta-D-glucoside (THSG), the major bioactive compound from Polygonum multiflorum Thunb., can efficiently inhibit the formation of AGEs in a dose-dependent manner by trapping reactive MGO under physiological conditions (pH 7.4, 37 degrees C). More than 60% MGO was trapped by THSG within 24 h, which was much more effective than resveratrol and its methylated derivative, pterostilbene, the two major bioactive dietary stilbenes. The major mono- and di-MGO adducts of THSG were successfully purified and found to be mixtures of tautomers. LC-MS and NMR data showed that positions 4 and 6 of the A ring were the major active sites for trapping MGO. It was also found that THSG could significantly inhibit the formation of AGEs in the human serum albumin (HSA)-MGO assay and both mono- and di-MGO adducts of THSG were detected in this assay using LC-MS. The results suggest that the ability of THSG to trap reactive dicarbonyl species makes it a potential natural inhibitor of AGEs.

  1. Application of Ultra-High-Performance Liquid Chromatography Coupled with LTQ-Orbitrap Mass Spectrometry for the Qualitative and Quantitative Analysis of Polygonum multiflorum Thumb. and Its Processed Products.

    PubMed

    Wang, Teng-Hua; Zhang, Jing; Qiu, Xiao-Hui; Bai, Jun-Qi; Gao, You-Heng; Xu, Wen

    2015-12-26

    In order to quickly and simultaneously obtain the chemical profiles and control the quality of the root of Polygonum multiflorum Thumb. and its processed form, a rapid qualitative and quantitative method, using ultra-high-performance liquid chromatography coupled with electrospray ionization-linear ion trap-Orbitrap hybrid mass spectrometry (UHPLC-LTQ-Orbitrap MS(n)) has been developed. The analysis was performed within 10 min on an AcQuity UPLC™ BEH C18 column with a gradient elution of 0.1% formic acid-acetonitrile at flow rate of 400 μL/min. According to the fragmentation mechanism and high resolution MS(n) data, a diagnostic ion searching strategy was used for rapid and tentative identification of main phenolic components and 23 compounds were simultaneously identified or tentatively characterized. The difference in chemical profiles between P. multiflorum and its processed preparation were observed by comparing the ions abundances of main constituents in the MS spectra and significant changes of eight metabolite biomarkers were detected in the P. multiflorum samples and their preparations. In addition, four of the representative phenols, namely gallic acid, trans-2,3,5,4'-tetra-hydroxystilbene-2-O-β-d-glucopyranoside, emodin and emodin-8-O-β-d-glucopyranoside were quantified by the validated UHPLC-MS/MS method. These phenols are considered to be major bioactive constituents in P. multiflorum, and are generally regarded as the index for quality assessment of this herb. The method was successfully used to quantify 10 batches of P. multiflorum and 10 batches of processed P. multiflorum. The results demonstrated that the method is simple, rapid, and suitable for the discrimination and quality control of this traditional Chinese herb.

  2. Feasibility of incorporating waste grass clippings (Lolium perenne L.) in particleboard composites.

    PubMed

    Nemli, Gökay; Demirel, Samet; Gümüşkaya, Esat; Aslan, Mustafa; Acar, Cengiz

    2009-03-01

    This study investigated some of the important physical (thickness swelling) and mechanical (modulus of rupture, modulus of elasticity and internal bond) properties of single-layer particleboard panels made from eucalyptus (Eucalyptus camaldulensis Dehn.), waste of grass clippings (Lolium perenne L.) and combinations of the two. The chemical properties (pH, holocelluse and alpha cellulose contents, and water, alcohol-benzene and 1% sodium hydroxide solubilities) of the raw materials were also determined. Panels with a 6:94 ratio of grass-to-eucalyptus particles had the required mechanical properties for interior fitments including furniture and general uses. Boards manufactured with 100% grass clippings exhibited the lowest quality. The overall panel properties improved with a lower percentage of grass clippings added. Based on initial results, it also appears that grass should compose no more than 13% to achieve acceptable panel properties for interior fitments and general uses.

  3. Antioxidant responses in Carassius auratus and Lolium perenne exposed to the laboratory pollution.

    PubMed

    Qiu, Jing; Feng, Mingbao; Wei, Zhongbo; Wang, Chao; Wang, Xinghao

    2014-03-01

    Experiments conducted in the laboratories can produce numerous wastes, which could potentially affect the health of the researchers. In this study, the antioxidant responses in liver of Carassiua auratus and leaf of Lolium perenne were investigated after chronic exposure to the air pollution in four different laboratories. The obtained data showed that oxidative stress was induced in some laboratories, as indicated by some significantly altered biochemical parameters. Additionally, the toxicity order was tentatively proposed based on these responses. The results indicated that these biochemical indices can be used as the oxidative stress biomarkers to assess the effect of environmental pollution on the living organisms, and this study can facilitate the understanding of the risk assessment of laboratory pollution. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. [Control of the fermentation activity during ensilage of Lolium italicum A. Br. and Medicago sativa L].

    PubMed

    Ozino Marletto, O I; Ambrosoli, R; Piccone, G; Biasiol, B

    1982-01-01

    Samples with different dry matter contents of Lolium italicum A. Br., Medicago sativa L., have been ensiled in hermetically sealed containers, in order to study the evolution of microflora and its activity. The principal microbial groups (coliforms, proteolytics , lactic acid bacteria, clostridia, yeasts) have been detected and enumerated, in anaerobic atmosphere, after ensiling periods of 3, 6, 10, 13, 20, 100 days. At the same time, the samples were chemically analyzed for the detection of: pH, moisture, ashes, total and ammoniacal nitrogen, total reducing sugars, lactic acid, volatile fatty acids, short chain alcohols. The relations found between chemical and microbiological data, show that a strong lactic fermentation is not enough for the inhibition of silage spoiling microorganisms, such as coliforms, yeasts, and (less) proteolytics . This phenomenon may be related to the "quality" of the lactic acid microflora, more than to the characteristics of the environment.

  5. Distinct non-target site mechanisms endow resistance to glyphosate, ACCase and ALS-inhibiting herbicides in multiple herbicide-resistant Lolium rigidum.

    PubMed

    Yu, Qin; Abdallah, Ibrahim; Han, Heping; Owen, Mechelle; Powles, Stephen

    2009-09-01

    This study investigates mechanisms of multiple resistance to glyphosate, acetyl-coenzyme A carboxylase (ACCase) and acetolactate synthase (ALS)-inhibiting herbicides in two Lolium rigidum populations from Australia. When treated with glyphosate, susceptible (S) plants accumulated 4- to 6-fold more shikimic acid than resistant (R) plants. The resistant plants did not have the known glyphosate resistance endowing mutation of 5-enolpyruvylshikimate-3 phosphate synthase (EPSPS) at Pro-106, nor was there over-expression of EPSPS in either of the R populations. However, [(14)C]-glyphosate translocation experiments showed that the R plants in both populations have altered glyphosate translocation patterns compared to the S plants. The R plants showed much less glyphosate translocation to untreated young leaves, but more to the treated leaf tip, than did the S plants. Sequencing of the carboxyl transferase domain of the plastidic ACCase gene revealed no resistance endowing amino acid substitutions in the two R populations, and the ALS in vitro inhibition assay demonstrated herbicide-sensitive ALS in the ALS R population (WALR70). By using the cytochrome P450 inhibitor malathion and amitrole with ALS and ACCase herbicides, respectively, we showed that malathion reverses chlorsulfuron resistance and amitrole reverses diclofop resistance in the R population examined. Therefore, we conclude that multiple glyphosate, ACCase and ALS herbicide resistance in the two R populations is due to the presence of distinct non-target site based resistance mechanisms for each herbicide. Glyphosate resistance is due to reduced rates of glyphosate translocation, and resistance to ACCase and ALS herbicides is likely due to enhanced herbicide metabolism involving different cytochrome P450 enzymes.

  6. Enhanced herbicide metabolism induced by 2,4-D in herbicide susceptible Lolium rigidum provides protection against diclofop-methyl.

    PubMed

    Han, Heping; Yu, Qin; Cawthray, Gregory R; Powles, Stephen B

    2013-09-01

    The auxinic herbicide 2,4-D amine is known, in vitro, as a cytochrome P450 inducer. The current study uses 2,4-D pre-treatment, at the whole plant level, to study mechanism(s) of non-target site based herbicide resistance to the ACCase-inhibiting herbicide diclofop-methyl in Lolium rigidum. The 2,4-D pre-treatment caused up to 10-fold shift in LD50 and GR50 in dose-response to subsequently applied diclofop-methyl in a herbicide susceptible L. rigidum population. Foliar uptake and translocation of (14) C-diclofop-methyl did not differ in 2,4-D pre-treated versus untreated plants. HPLC analysis revealed that de-esterification of diclofop-methyl to toxic diclofop acid was similar, but further metabolism of diclofop acid to non-toxic metabolites was significantly (1.8-fold) faster in 2,4-D pre-treated than untreated plants. HPLC profile of major polar metabolites was similar when L. rigidum and diclofop-methyl tolerant wheat were compared, but wheat metabolised diclofop acid three-fold faster than L. rigidum. In addition, 2,4-D pre-treatment also induced cross-protection against the ALS-inhibiting herbicide chlorsulfuron, and the known P450 inhibitor malathion can reverse this effect. Protection against diclofop-methyl provided by 2,4-D pre-treatment in susceptible L. rigidum is associated with higher rates of herbicide metabolism, mirroring that identified in field-evolved, non-target site-based diclofop-methyl resistant populations. 2,4-D may induce higher level expression of herbicide-metabolising genes hence providing protection, and therefore, this 2,4-D induction system can be used, in combination with other genomic approaches, to assist isolating cytochrome P450 and other genes that are involved in herbicide metabolism and endow herbicide resistance in L. rigidum. © 2013 Society of Chemical Industry.

  7. Population

    EPA Science Inventory

    Population growth influences many stressors on Narragansett Bay and its Watershed, including all landscape and chemical stressors discussed in other chapters of this report. In numerous ways, population growth affects the condition of the Bay ecosystem, Watershed ecosystem, and h...

  8. [Population].

    PubMed

    1979-01-01

    Data on the population of Venezuela between 1975 and 1977 are presented in descriptive tables and graphs. Information is included on the employed population according to category, sex, and type of economic activity, and by sex, age, and area on the employment rate and the total, the economically active, and the unemployed population.

  9. Population.

    ERIC Educational Resources Information Center

    King, Pat; Landahl, John

    This pamphlet has been prepared in response to a new problem, a rapidly increasing population, and a new need, population education. It is designed to help teachers provide their students with some basic population concepts with stress placed on the elements of decision making. In the first section of the pamphlet, some of the basic concepts of…

  10. Micropropagation of Polygonum multiflorum THUNB and quantitative analysis of the anthraquinones emodin and physcion formed in in vitro propagated shoots and plants.

    PubMed

    Lin, Li-Chang; Nalawade, Satish Manohar; Mulabagal, Vanisree; Yeh, Mau-Shing; Tsay, Hsin-Sheng

    2003-10-01

    An efficient and rapid protocol for in vitro induction and complete plant regeneration of Polygonum multiflorum THUNB has been developed. Nodal explants were grown in vitro on Murashige and Skoog's (MS) basal medium containing different concentrations of alpha-naphthaleneacetic acid (NAA) and benzyladenine (BA). The nodal explants (97%) produced multiple shoots (4.7 shoots per explant) on MS basal medium supplemented with 0.2 mg/l NAA and 2.0 mg/l BA after 6 weeks of culture. Eighty-eight percent to 100% of the shoots (1.0 cm in length) elongated (about 3.02-4.28 cm) and rooted on MS basal medium supplemented with NAA or indole-3-butyric acid (IBA). All the rooted shoots were transferred to pots containing autoclaved soil, vermiculite, and peat moss (1 : 1 : 1). The plantlets were successfully acclimatized under greenhouse conditions with high humidity before transferring to the field. The anthraquinone contents were determined using HPLC. Analysis revealed that the contents of the major medicinal compounds-emodin and physcion in the 6 weeks old in vitro grown shoots and three month old in vitro propagated plants grown in greenhouse were higher than those of the marketed crude drug (processed underground or stem parts of P. multiflorum).

  11. [Recent advances in anti-aging study of 2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucopyranoside--a main component of Polygonum multiflorum].

    PubMed

    Li, Yi-Han; Wang, Yue-Fei; Zhu, Yan

    2016-01-01

    Aging is an inevitable process of life caused by a combination of organs and tissues events which manifests as loss of structure and function. It is accompanied with organ hypofunction, decline in defense against stress and energy metabolism, and lots of age-related diseases. Therefore, it is critical to understand the mechanism of aging, as well as to discover new drugs to slow aging. Polygonum multiflorum has long been recognized in traditional Chinese medicine as anti-aging medicine. Interestingly, its extract has been shown to prolong lifespan in drosophila and elegans. Tetrahydroxystilbene glucoside (TSG), the main ingredient of P. multiflorum, shares a strong structural similarity with resveratrol, a well-known anti-aging natural product. This review summarized up-to-date literature reports and our laboratory findings on the mechanism of TSG anti-aging efficiency and function against age-related disease. It could provide reference for searching for anti-aging tradition Chinese medicine. Copyright© by the Chinese Pharmaceutical Association.

  12. [Polyketone Reaction in Biosynthetic Pathways of 2, 3, 5, 4'-Tetrahydroxy Stilhene-2-O-β-D-glucoside in Polygonum multiflorum by Biocatalysis].

    PubMed

    Lei, Lei; Xia, Wan-xia; Shao, Li; Zhao, Shu-jin

    2015-10-01

    2, 3, 5, 4'-Tetrahydroxy stilbene-2-O-β-D-glucoside (THSG), the active ingredient of Polygonum multiflorum, its polyketone reaction in the biosynthesis pathways was studied by biocatalysis method. The substrates 4-coumaroyl-CoA and malonyl-CoA were catalyzed in vitro by the crude enzyme extracted from Polygonum multiflorum callus, then the products were verified by HPLC and LC-MS methods. And the crude enzyme was analyzed by ammonium sulfate precipitation method and SDS-PAGE. HPLC chromatogram showed the same retention time of both the product and resveratrol standards; LC-MS spectra showed that the m/z of product was 227, which was consistent with resveratrol standards under the mode of negative ion; Ammonium sulfate (AS) precipitation method showed AS of 40% - 70% had catalytic activity,and 50% - 60% was the optimum; SDS-PAGE showed protein bands were obviously different among different AS concentration between 20% - 80%, the protein band of 42 kDa was found in AS of 50% - 60%, which had the same molecular weight with stilbene synthase. The product of polyketone reaction in the biosynthesis of THSG is resveratrol rather than THSG, so it is speculated that THSG is the conversion product of resveratrol instead of the direct product of the polyketone reaction.

  13. Insights into the molecular mechanisms of Polygonum multiflorum Thunb-induced liver injury: a computational systems toxicology approach.

    PubMed

    Wang, Yin-Yin; Li, Jie; Wu, Zeng-Rui; Zhang, Bo; Yang, Hong-Bin; Wang, Qin; Cai, Ying-Chun; Liu, Gui-Xia; Li, Wei-Hua; Tang, Yun

    2017-02-27

    An increasing number of cases of herb-induced liver injury (HILI) have been reported, presenting new clinical challenges. In this study, taking Polygonum multiflorum Thunb (PmT) as an example, we proposed a computational systems toxicology approach to explore the molecular mechanisms of HILI. First, the chemical components of PmT were extracted from 3 main TCM databases as well as the literature related to natural products. Then, the known targets were collected through data integration, and the potential compound-target interactions (CTIs) were predicted using our substructure-drug-target network-based inference (SDTNBI) method. After screening for hepatotoxicity-related genes by assessing the symptoms of HILI, a compound-target interaction network was constructed. A scoring function, namely, Ascore, was developed to estimate the toxicity of chemicals in the liver. We conducted network analysis to determine the possible mechanisms of the biphasic effects using the analysis tools, including BiNGO, pathway enrichment, organ distribution analysis and predictions of interactions with CYP450 enzymes. Among the chemical components of PmT, 54 components with good intestinal absorption were used for analysis, and 2939 CTIs were obtained. After analyzing the mRNA expression data in the BioGPS database, 1599 CTIs and 125 targets related to liver diseases were identified. In the top 15 compounds, seven with Ascore values >3000 (emodin, quercetin, apigenin, resveratrol, gallic acid, kaempferol and luteolin) were obviously associated with hepatotoxicity. The results from the pathway enrichment analysis suggest that multiple interactions between apoptosis and metabolism may underlie PmT-induced liver injury. Many of the pathways have been verified in specific compounds, such as glutathione metabolism, cytochrome P450 metabolism, and the p53 pathway, among others. Hepatitis symptoms, the perturbation of nine bile acids and yellow or tawny urine also had corresponding pathways

  14. Influence of an Elevated Atmospheric CO2 Content on Soil and Rhizosphere Bacterial Communities Beneath Lolium perenne and Trifolium repens under Field Conditions.

    PubMed

    Marilley; Hartwig; Aragno

    1999-07-01

    > Abstract The increase in atmospheric CO2 content alters C3 plant photosynthetic rate, leading to changes in rhizodeposition and other root activities. This may influence the activity, the biomass, and the structure of soil and rhizosphere microbial communities and therefore the nutrient cycling rates and the plant growth. The present paper focuses on bacterial numbers and on community structure. The rhizospheres of two grassland plants, Lolium perenne (ryegrass) and Trifolium repens (white clover), were divided into three fractions: the bulk soil, the rhizospheric soil, and the rhizoplane-endorhizosphere. The elevated atmospheric CO2 content increased the most probable numbers of heterotrophic bacteria in the rhizosphere of L. perenne. However, this effect lasted only at the beginning of the vegetation period for T. repens. Community structure was assessed after isolation of DNA, PCR amplification, and construction of cloned 16S rDNA libraries. Amplified ribosomal DNA restriction analysis (ARDRA) and colony hybridization with an oligonucleotide probe designed to detect Pseudomonas spp. showed under elevated atmospheric CO2 content an increased dominance of pseudomonads in the rhizosphere of L. perenne and a decreased dominance in the rhizosphere of T. repens. This work provides evidence for a CO2-induced alteration in the structure of the rhizosphere bacterial populations, suggesting a possible alteration of the plant-growth-promoting-rhizobacterial (PGPR) effect.http://link.springer-ny.com/link/service/journals/00248/bibs/38n1p39.html

  15. Selection for low or high primary dormancy in Lolium rigidum Gaud seeds results in constitutive differences in stress protein expression and peroxidase activity

    PubMed Central

    Goggin, Danica E.; Powles, Stephen B.; Steadman, Kathryn J.

    2011-01-01

    Seed dormancy in wild Lolium rigidum Gaud (annual ryegrass) populations is highly variable and not well characterized at the biochemical level. To identify some of the determinants of dormancy level in these seeds, the proteomes of subpopulations selected for low and high levels of primary dormancy were compared by two-dimensional polyacrylamide gel electrophoresis of extracts from mature, dry seeds. High-dormancy seeds showed higher expression of small heat shock proteins, enolase, and glyoxalase I than the low-dormancy seeds. The functional relevance of these differences in protein expression was confirmed by the fact that high-dormancy seeds were more tolerant to high temperatures imposed at imbibition and had consistently higher glyoxalase I activity over 0–42 d dark stratification. Higher expression of a putative glutathione peroxidase in low-dormancy seeds was not accompanied by higher activity, but these seeds had a slightly more oxidized glutathione pool and higher total peroxidase activity. Overall, these biochemical and physiological differences suggest that L. rigidum seeds selected for low dormancy are more prepared for rapid germination via peroxidase-mediated cell wall weakening, whilst seeds selected for high dormancy are constitutively prepared to survive environmental stresses, even in the absence of stress during seed development. PMID:20974739

  16. Population.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    In an effort to help meet the growing interest and concern about the problems created by the rapid growth of population, The International Planned Parenthood Federation has prepared this booklet with the aim of assisting the study of the history and future trends of population growth and its impact on individual and family welfare, national,…

  17. Allergen Microarray Indicates Pooideae Sensitization in Brazilian Grass Pollen Allergic Patients

    PubMed Central

    Moreira, Priscila Ferreira de Sousa; Gangl, Katharina; Vieira, Francisco de Assis Machado; Ynoue, Leandro Hideki; Linhart, Birgit; Flicker, Sabine; Fiebig, Helmut; Swoboda, Ines; Focke-Tejkl, Margarete; Taketomi, Ernesto Akio; Valenta, Rudolf; Niederberger, Verena

    2015-01-01

    Background Grass pollen, in particular from Lolium multiflorum is a major allergen source in temperate climate zones of Southern Brazil. The IgE sensitization profile of Brazilian grass pollen allergic patients to individual allergen molecules has not been analyzed yet. Objective To analyze the IgE sensitization profile of a Brazilian grass pollen allergic population using individual allergen molecules. Methods We analyzed sera from 78 grass pollen allergic patients for the presence of IgE antibodies specific for 103 purified micro-arrayed natural and recombinant allergens by chip technology. IgE-ELISA inhibition experiments with Lolium multiflorum, Phleum pratense extracts and a recombinant fusion protein consisting of Phl p 1, Phl p 2, Phl p 5 and Phl p 6 were performed to investigate cross-reactivities. Results Within the Brazilian grass pollen allergic patients, the most frequently recognized allergens were Phl p 1 (95%), Phl p 5 (82%), Phl p 2 (76%) followed by Phl p 4 (64%), Phl p 6 (45%), Phl p 11 (18%) and Phl p 12 (18%). Most patients were sensitized only to grass pollen allergens but not to allergens from other sources. A high degree of IgE cross-reactivity between Phleum pratense, Lolium multiflorum and the recombinant timothy grass fusion protein was found. Conclusions Component-resolved analysis of sera from Brazilian grass pollen allergic patients reveals an IgE recognition profile compatible with a typical Pooideae sensitization. The high degree of cross-reactivity between Phleum pratense and Lolium multiflorum allergens suggests that diagnosis and immunotherapy can be achieved with timothy grass pollen allergens in the studied population. PMID:26067084

  18. Plant uptake and phytotoxicity of decabromodiphenyl ether (BDE-209) in ryegrass (Lolium perenne L).

    PubMed

    Xie, Xianchuan; Qian, Yan; Xue, Yingang; He, Huan; Wei, Dongyang

    2013-10-01

    The plant uptake and phytotoxicity of decabromodiphenyl ether (BDE-209) in ryegrass (Lolium perenne L) seedlings were investigated. Results showed that ryegrass could take up BDE-209 from the contaminated soils and most of the BDE-209 in plants is located in roots, indicating that BDE-209 has low root-to-shoot translocation. Except for about 35% inhibition of root growth and about 30% decrease of the chlorophyll b and carotenoid contents of leaves, no visual toxicity symptoms were observed in seedlings grown even at a high concentration of 100 mg kg(-1). BDE-209 exposure significantly induced the generation of the superoxide radical (O2˙(-)) and malondialdehyde (MDA) in ryegrass leaves. With the increase of BDE-209 concentration, the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione-S-transferase (GST) were significantly changed, and the ratio of reduced glutathione to oxidized glutathione (GSH/GSSG) was also significantly reduced. Results suggested that BDE-209 exposure could cause oxidative stress and damage, which may play an important role in the phytotoxicity of BDE-209 in ryegrass seedlings.

  19. High nitrogen supply and carbohydrate content reduce fungal endophyte and alkaloid concentration in Lolium perenne.

    PubMed

    Rasmussen, Susanne; Parsons, Anthony J; Bassett, Shalome; Christensen, Michael J; Hume, David E; Johnson, Linda J; Johnson, Richard D; Simpson, Wayne R; Stacke, Christina; Voisey, Christine R; Xue, Hong; Newman, Jonathan A

    2007-01-01

    The relationship between cool-season grasses and fungal endophytes is widely regarded as mutualistic, but there is growing uncertainty about whether changes in resource supply and environment benefit both organisms to a similar extent. Here, we infected two perennial ryegrass (Lolium perenne) cultivars (AberDove, Fennema) that differ in carbohydrate content with three strains of Neotyphodium lolii (AR1, AR37, common strain) that differ intrinsically in alkaloid profile. We grew endophyte-free and infected plants under high and low nitrogen (N) supply and used quantitative PCR (qPCR) to estimate endophyte concentrations in harvested leaf tissues. Endophyte concentration was reduced by 40% under high N supply, and by 50% in the higher sugar cultivar. These two effects were additive (together resulting in 75% reduction). Alkaloid production was also reduced under both increased N supply and high sugar cultivar, and for three of the four alkaloids quantified, concentrations were linearly related to endophyte concentration. The results stress the need for wider quantification of fungal endophytes in the grassland-foliar endophyte context, and have implications for how introducing new cultivars, novel endophytes or increasing N inputs affect the role of endophytes in grassland ecosystems.

  20. ABA inhibits germination but not dormancy release in mature imbibed seeds of Lolium rigidum Gaud.

    PubMed

    Goggin, Danica E; Steadman, Kathryn J; Emery, R J Neil; Farrow, Scott C; Benech-Arnold, Roberto L; Powles, Stephen B

    2009-01-01

    Dormancy release in imbibed annual ryegrass (Lolium rigidum Gaud.) seeds is promoted in the dark but inhibited in the light. The role of abscisic acid (ABA) in inhibition of dormancy release was found to be negligible, compared with its subsequent effect on germination of dormant and non-dormant seeds. Inhibitors of ABA metabolism had the expected effects on seed germination but did not influence ABA concentration, suggesting that they act upon other (unknown) factors regulating dormancy. Although gibberellin (GA) synthesis was required for germination, the influence of exogenous GA on both germination and dormancy release was minor or non-existent. Embryo ABA concentration was the same following treatments to promote (dark stratification) and inhibit (light stratification) dormancy release; exogenous ABA had no effect on this process. However, the sensitivity of dark-stratified seeds to ABA supplied during germination was lower than that of light-stratified seeds. Therefore, although ABA definitely plays a role in the germination of annual ryegrass seeds, it is not the major factor mediating inhibition of dormancy release in imbibed seeds.

  1. Early response mechanisms of perennial ryegrass (Lolium perenne) to phosphorus deficiency

    PubMed Central

    Byrne, Stephen L.; Foito, Alexandre; Hedley, Pete E.; Morris, Jenny A.; Stewart, Derek; Barth, Susanne

    2011-01-01

    Background and Aims Improving phosphorus (P) nutrient efficiency in Lolium perenne (perennial ryegrass) is likely to result in considerable economic and ecological benefits. To date, research into the molecular and biochemical response of perennial ryegrass to P deficiency has been limited, particularly in relation to the early response mechanisms. This study aimed to identify molecular mechanisms activated in response to the initial stages of P deficiency. Methods A barley microarray was successfully used to study gene expression in perennial ryegrass and this was complemented with gas chromatography-mass spectrometry metabolic profiling to obtain an overview of the plant response to early stages of P deficiency. Key Results After 24 h of P deficiency, internal phosphate concentrations were reduced and significant alterations were detected in the metabolome and transcriptome of two perennial ryegrass genotypes. Results indicated a replacement of phospholipids with sulfolipids and the utilization of glycolytic bypasses in response to P deficiency in perennial ryegrass. Conclusions The transcriptome and metabolome of perennial ryegrass undergo changes in response to reductions in P supply after 24 h. PMID:21148585

  2. Metabolite profiling during cold acclimation of Lolium perenne genotypes distinct in the level of frost tolerance.

    PubMed

    Bocian, Aleksandra; Zwierzykowski, Zbigniew; Rapacz, Marcin; Koczyk, Grzegorz; Ciesiołka, Danuta; Kosmala, Arkadiusz

    2015-11-01

    Abiotic stresses, including low temperature, can significantly reduce plant yielding. The knowledge on the molecular basis of stress tolerance could help to improve its level in species of relatively high importance to agriculture. Unfortunately, the complex research performed so far mainly on model species and also, to some extent, on cereals does not fully cover the demands of other agricultural plants of temperate climate, including forage grasses. Two Lolium perenne (perennial ryegrass) genotypes with contrasting levels of frost tolerance, the high frost tolerant (HFT) and the low frost tolerant (LFT) genotypes, were selected for comparative metabolomic research. The work focused on the analysis of leaf metabolite accumulation before and after seven separate time points of cold acclimation. Gas chromatography-mass spectrometry (GC/MS) was used to identify amino acids (alanine, proline, glycine, glutamic and aspartic acid, serine, lysine and asparagine), carbohydrates (fructose, glucose, sucrose, raffinose and trehalose) and their derivatives (mannitol, sorbitol and inositol) accumulated in leaves in low temperature. The observed differences in the level of frost tolerance between the analysed genotypes could be partially due to the time point of cold acclimation at which the accumulation level of crucial metabolite started to increase. In the HFT genotype, earlier accumulation was observed for proline and asparagine. The increased amounts of alanine, glutamic and aspartic acids, and asparagine during cold acclimation could be involved in the regulation of photosynthesis intensity in L. perenne. Among the analysed carbohydrates, only raffinose revealed a significant association with the acclimation process in this species.

  3. Physical and genetic mapping in the grasses Lolium perenne and Festuca pratensis.

    PubMed Central

    King, J; Armstead, I P; Donnison, I S; Thomas, H M; Jones, R N; Kearsey, M J; Roberts, L A; Thomas, A; Morgan, W G; King, I P

    2002-01-01

    A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line 2n = 2x = 14. In this line recombination occurs throughout the length of the F. pratensis/L. perenne bivalent. The F. pratensis chromosome and recombinants between it and its L. perenne homeologue can be visualized using genomic in situ hybridization (GISH). GISH junctions represent the physical locations of sites of recombination, enabling a range of recombinant chromosomes to be used for physical mapping of the introgressed F. pratensis chromosome. The physical map, in conjunction with a genetic map composed of 104 F. pratensis-specific amplified fragment length polymorphisms (AFLPs), demonstrated: (1) the first large-scale analysis of the physical distribution of AFLPs; (2) variation in the relationship between genetic and physical distance from one part of the F. pratensis chromosome to another (e.g., variation was observed between and within chromosome arms); (3) that nucleolar organizer regions (NORs) and centromeres greatly reduce recombination; (4) that coding sequences are present close to the centromere and NORs in areas of low recombination in plant species with large genomes; and (5) apparent complete synteny between the F. pratensis chromosome and rice chromosome 1. PMID:12019245

  4. Pollen-Mediated Movement of Herbicide Resistance Genes in Lolium rigidum.

    PubMed

    Loureiro, Iñigo; Escorial, María-Concepción; Chueca, María-Cristina

    2016-01-01

    The transfer of herbicide resistance genes by pollen is a major concern in cross-pollinated species such as annual ryegrass (Lolium rigidum). A two-year study was conducted in the greenhouse, under favorable conditions for pollination, to generate information on potential maximum cross-pollination. This maximum cross-pollination rate was 56.1%. A three-year field trial was also conducted to study the cross-pollination rates in terms of distance and orientation to an herbicide-resistant pollen source. Under field conditions, cross-pollination rates varied from 5.5% to 11.6% in plants adjacent to the pollen source and decreased with increasing distances (1.5 to 8.9% at 15 m distance and up to 4.1% at 25 m in the downwind direction). Environmental conditions influenced the cross-pollination both under greenhouse and field conditions. Data were fit to an exponential decay model to predict gene flow at increasing distances. This model predicted an average gene flow of 7.1% when the pollen donor and recipient plants were at 0 m distance from each other. Pollen-mediated gene flow declined by 50% at 16.7 m from the pollen source, yet under downwind conditions gene flow of 5.2% was predicted at 25 m, the farthest distance studied. Knowledge of cross-pollination rates will be useful for assessing the spread of herbicide resistance genes in L. rigidum and in developing appropriate strategies for its mitigation.

  5. Cryopreservation Of Nili-Ravi Buffalo Bull Sperm in Cryodiluent Supplemented with Lolium perenne Protein Preparations.

    PubMed

    Qadeer, S; Khan, M A; Ansari, M S; Rakha, B A; Ejaz, R; Husna, A U; Azam, A; Ullah, N; Walker, V K; Akhter, S

    Semen from the Nili-Ravi buffalo bull, Bubalus bubalis, shows poor survival after freeze storage compared to bovine (Bos taurus and Bos indicus) semen. Freeze-susceptibility distinctions in these two genera have been attributed to differences in sperm membranes. We measured the impact of protein preparations derived from a frost-resistant perennial grass, Lolium perenne, with ice recrystallization inhibition activity on the low temperature storage of B. bubalis semen. When the L. perenne preparations (0.1, 1, 10 µg/mL) were added to buffalo semen [2 ejaculates per bull (N=3) per replicate (r=3)] in Tris-citrate extender (50×10(6)sperm mL(-1)), there was no impact on semen quality, as measured by sperm motility and plasma membrane integrity, after storage at 4 degree C (P>0.05). However, when semen supplemented with the grass proteins (0.1 and 1 µg mL(-1)) was evaluated after freezing and storage in liquid nitrogen for 24 h, post-thaw sperm progressive motility and plasma membrane integrity was higher (P<0.05) than in control samples. Post-thaw sperm viability and sperm acrosome integrity was similar (P > 0.05) to controls. The improvement in cryopreserved buffalo sperm progressive motility and plasma membrane integrity suggests that the use of these easily-made preparations may improve fertility after cryopreservation and offers the prospect of improved conception rates after artificial insemination with cryopreservation.

  6. Monoclonal antibodies to the major Lolium perenne (rye grass) pollen allergen Lol p I (Rye I).

    PubMed

    Kahn, C R; Marsh, D G

    1986-12-01

    Thirteen monoclonal antibodies (MAbs) were produced against Lol p I (Rye I), the major Lolium perenne (rye grass) pollen allergen. Spleen cells from A/J and SJL mice immunized with highly purified Lol p I (Lol I) were allowed to fuse with cells from the non-secreting Sp2/0-Ag14 myeloma cell line. Each MAb was analyzed for antigenic specificity by radioimmunoassay (RIA) using 125I-Lol I. The epitope specificities of seven of the MAbs were examined by competitive binding against a labelled standard MAb for the Lol I antigen (Ag). The dissociation constant, Kd, of one MAb (No. 3.2) that was studied most extensively was determined by double Ab RIA to be 3.5 X 10(-6) L/M. This MAb recognized the related 27,000-30,000 Group I glycoproteins found in the pollens of nine other species of grass pollens tested, including weak binding to Bermuda grass Group I (Cyn d I), which by conventional analysis using polyclonal anti-Lol I serum shows no detectable binding. Monoclonal antibody No. 3.2 was coupled covalently to Sepharose 4B and used to prepare highly purified Lol I from a partially purified rye pollen extract. Finally, an RIA was developed which permitted the analysis of the Group I components in rye grass and nine other grass pollen species. The latter assay is likely to prove useful in the standardization of grass pollen extracts according to their Group I contents.

  7. Complete amino acid sequence of a Lolium perenne (perennial rye grass) pollen allergen, Lol p II.

    PubMed

    Ansari, A A; Shenbagamurthi, P; Marsh, D G

    1989-07-05

    The complete amino acid sequence of a Lolium perenne (rye grass) pollen allergen, Lol p II was determined by automated Edman degradation of the protein and selected fragments. Cleavage of the protein by enzymatic and chemical techniques established an unambiguous sequence for the protein. Lol p II contains 97 amino acid residues, with a calculated molecular weight of 10,882. The protein lacks cysteine and glutamine and shows no evidence of glycosylation. Theoretical predictions by Fraga's (Fraga, S. (1982) Can. J. Chem. 60, 2606-2610) and Hopp and Woods' (Hopp, T. P., and Woods, K. R. (1981) Proc. Natl. Acad. Sci. U.S.A. 78, 3824-3828) methods indicate the presence of four hydrophilic regions, which may contribute to sequential or parts of conformational B-cell epitopes. Analysis of amphipathic regions by Berzofsky's method indicates the presence of a highly amphipathic region, which may contain, or contribute to, an Ia/T-cell epitope. This latter segment of Lol p II was found to be highly homologous with an antibody-binding segment of the major rye allergen Lol p I and may explain why immune responsiveness to both the allergens is associated with HLA-DR3.

  8. Activation of sucrose transport in defoliated Lolium perenne L.: an example of apoplastic phloem loading plasticity.

    PubMed

    Berthier, Alexandre; Desclos, Marie; Amiard, Véronique; Morvan-Bertrand, Annette; Demmig-Adams, Barbara; Adams, William W; Turgeon, Robert; Prud'homme, Marie-Pascale; Noiraud-Romy, Nathalie

    2009-07-01

    The pathway of carbon phloem loading was examined in leaf tissues of the forage grass Lolium perenne. The effect of defoliation (leaf blade removal) on sucrose transport capacity was assessed in leaf sheaths as the major carbon source for regrowth. The pathway of carbon transport was assessed via a combination of electron microscopy, plasmolysis experiments and plasma membrane vesicles (PMVs) purified by aqueous two-phase partitioning from the microsomal fraction. Results support an apoplastic phloem loading mechanism. Imposition of an artificial proton-motive force to PMVs from leaf sheaths energized an active, transient and saturable uptake of sucrose (Suc). The affinity of Suc carriers for Suc was 580 microM in leaf sheaths of undefoliated plants. Defoliation induced a decrease of K(m) followed by an increase of V(max). A transporter was isolated from stubble (including leaf sheaths) cDNA libraries and functionally expressed in yeast. The level of L.perenne SUcrose Transporter 1 (LpSUT1) expression increased in leaf sheaths in response to defoliation. Taken together, the results indicate that Suc transport capacity increased in leaf sheaths of L. perenne in response to leaf blade removal. This increase might imply de novo synthesis of Suc transporters, including LpSUT1, and may represent one of the mechanisms contributing to rapid refoliation.

  9. Depletion of carbohydrate reserves limits nitrate uptake during early regrowth in Lolium perenne L.

    PubMed Central

    Guo, Qianqian; Turnbull, Matthew Hamish; Song, Jiancheng; Roche, Jessica; Novak, Ondrej; Späth, Jana; Love, Jonathan

    2017-01-01

    Abstract The mechanisms linking C/N balance to N uptake and assimilation are central to plant responses to changing soil nutrient levels. Defoliation and subsequent regrowth of grasses both impact C partitioning, thereby creating a significant point of interaction with soil N availability. Using defoliation as an experimental treatment, we investigated the dynamic relationships between plant carbohydrate status and NO3–-responsive uptake systems, transporter gene expression, and nitrate assimilation in Lolium perenne L. High- and low-affinity NO3– uptake was reduced in an N-dependent manner in response to a rapid and large shift in carbohydrate remobilization triggered by defoliation. This reduction in NO3– uptake was rescued by an exogenous glucose supplement, confirming the carbohydrate dependence of NO3– uptake. The regulation of NO3– uptake in response to the perturbation of the plant C/N ratio was associated with changes in expression of putative high- and low-affinity NO3– transporters. Furthermore, NO3– assimilation appears to be regulated by the C–N status of the plant, implying a mechanism that signals the availability of C metabolites for NO3– uptake and assimilation at the whole-plant level. We also show that cytokinins may be involved in the regulation of N acquisition and assimilation in response to the changing plant C/N ratio. PMID:28379423

  10. Amendments promote the development of Lolium perenne in soils affected by historical copper smelting operations.

    PubMed

    Goecke, Paul; Ginocchio, Rosanna; Mench, Michel; Neaman, Alexander

    2011-07-01

    The Puchuncaví valley, central Chile, has been exposed to aerial emissions from a copper smelter. Nowadays, soils in the surroundings are sparsely-vegetated, acidic, and metal-contaminated, and their remediation is needed to reduce environmental risks. We assessed effectiveness of lime, fly ash, compost, and iron grit as amendments to immobilize Cu in soils and promote plant growth. Amended soils were cultivated with Lolium perenne for 60 days under controlled conditions. Total dissolved Cu and Cu2+ activity in the soil solution, ryegrass biomass, and Cu accumulation in plant tissues were measured. Addition of lime and fly ash decreased Cu concentrations and Cu2+ activity in the soil solution, increased plant biomass, and reduced shoot Cu concentration below 22 mg kg(-1) (the phytotoxicity threshold for the species). The most effective amendment with respect to the shoot biomass yield was a combination of lime and compost. Water content of the substrate and the K accumulation were positively correlated with the compost application rate. Compost combined with iron grit decreased dissolved Cu concentrations during the period of highest solubility, i.e., during the first 60 days after the compost application. However, iron grit incorporation into soils amended with lime and compost decreased the shoot biomass of ryegrass.

  11. Toxicity and uptake of cyclic nitramine explosives in ryegrass Lolium perenne.

    PubMed

    Rocheleau, Sylvie; Lachance, Bernard; Kuperman, Roman G; Hawari, Jalal; Thiboutot, Sonia; Ampleman, Guy; Sunahara, Geoffrey I

    2008-11-01

    Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) are cyclic nitramines used as explosives. Their ecotoxicities have been characterized incompletely and little is known about their accumulation potential in soil organisms. We assessed the toxicity and uptake of these explosives in perennial ryegrass Lolium perenne L. exposed in a Sassafras sandy loam (SSL) or in a sandy soil (DRDC, CL-20 only) containing contrasting clay contents (11% and 0.3%, respectively). A 21-d exposure to RDX, HMX or CL-20 in either soil had no adverse effects on ryegrass growth. RDX and HMX were translocated to ryegrass shoots, with bioconcentration factors (BCF) of up to 15 and 11, respectively. In contrast, CL-20 was taken up by the roots (BCF up to 19) with no translocation to the shoots. These studies showed that RDX, HMX, and CL-20 can accumulate in plants and may potentially pose a risk of biomagnification across the food chain.

  12. ABA inhibits germination but not dormancy release in mature imbibed seeds of Lolium rigidum Gaud.

    PubMed Central

    Goggin, Danica E.; Steadman, Kathryn J.; Emery, R. J. Neil; Farrow, Scott C.; Benech-Arnold, Roberto L.; Powles, Stephen B.

    2009-01-01

    Dormancy release in imbibed annual ryegrass (Lolium rigidum Gaud.) seeds is promoted in the dark but inhibited in the light. The role of abscisic acid (ABA) in inhibition of dormancy release was found to be negligible, compared with its subsequent effect on germination of dormant and non-dormant seeds. Inhibitors of ABA metabolism had the expected effects on seed germination but did not influence ABA concentration, suggesting that they act upon other (unknown) factors regulating dormancy. Although gibberellin (GA) synthesis was required for germination, the influence of exogenous GA on both germination and dormancy release was minor or non-existent. Embryo ABA concentration was the same following treatments to promote (dark stratification) and inhibit (light stratification) dormancy release; exogenous ABA had no effect on this process. However, the sensitivity of dark-stratified seeds to ABA supplied during germination was lower than that of light-stratified seeds. Therefore, although ABA definitely plays a role in the germination of annual ryegrass seeds, it is not the major factor mediating inhibition of dormancy release in imbibed seeds. PMID:19487389

  13. Phytochelatin synthesis in response to elevated CO2 under cadmium stress in Lolium perenne L.

    PubMed

    Jia, Yan; Ju, Xuehai; Liao, Shangqiang; Song, Zhengguo; Li, Zhongyang

    2011-10-15

    The increasing atmospheric CO(2) and heavy metal contamination in soil are two of the major environmental problems. Knowledge of the Cd stress coping mechanisms is needed to understand the regulation of the plants' metabolism under the increasing atmospheric CO(2) levels. Lolium perenne L. was grown hydroponically under two concentrations of atmospheric CO(2) (360 and 1000μLL(-1)) and six concentrations of cadmium (0-160μmolL(-1)) to investigate Cd uptake, Cd transportation, and variations in phytochelatin (PC) concentration. Cd concentrations in roots and shoots were decreased, but transport index (Ti) was increased under elevated CO(2) compared to ambient CO(2). Regardless of CO(2) concentrations, Cd and PC concentrations, especially the concentrations of high molecular weight PCs (PC(4), PC(5), PC(6)) were higher with increasing Cd concentration in growth media and longer Cd exposure time. Under the elevated CO(2), more high molecular weight PCs (PC(4), PC(5), PC(6)) in shoots and roots were synthesized compared to ambient CO(2), with higher SH:Cd ratio in roots as well. These results indicate that under elevated CO(2), L. perenne may be better protected against Cd stress with higher biomass, lower Cd concentration and better detoxification by phytochelatins. Copyright © 2011 Elsevier GmbH. All rights reserved.

  14. Gene expression analysis of perennial ryegrass (Lolium perenne) using cDNA microarrays

    NASA Astrophysics Data System (ADS)

    Ong, Eng-Kok; Sawbridge, Tim; Webster, Tracie; Emmerling, Michael; Nguyen, Nga; Nunan, Katrina; O'Neill, Matthew; O'Toole, Fiona; Rhodes, Carolyn; Simmonds, Jason; Tian, Pei; Wearne, Katherine; Winkworth, Amanda; Spangenberg, German

    2003-07-01

    Perennial ryegrass (Lolium perenne) is a major forage grass of temperate pastures. A genomics program has been undertaken generating over 52,000 expressed sequence tags (ESTs). Cluster analysis of the ESTs identified approximately 14,600 ryegrass unigenes. In this report, we described the application of ryegrass unigene cDNAs to produce ryegrass 15K microarray. Fifteen microarray hybridisations were performed with labeled total RNA isolated from a variety of plant organs and developmental stages. In a proof of concept, gene expression profiling of ryegrass ESTs using the 15K unigene microarrays has been established using several known genes and two cluster analysis approaches (parallel coordinate planes plot and hierarchical clustering). The expression profile of the known genes (e.g. rubisco and invertase) corresponds well with published data. The microarray expression profile of a ryegrass putative root specific kinase gene was also verified with Northern blotting. This combination of DNA microarray hybridisations and cluster analysis can be applied as a tool for the identification of novel sequences of unknown function.

  15. [Effects of loess soil stabilization on Lolium perenne L. growth and root activity].

    PubMed

    Liu, Yue-mei; Zhang, Xing-chang; Wang, Dan-dan

    2011-10-01

    Taking the loess soils with bulk density 1.2 g cm(-3), 1.3 g cm(-3), and 1.4 g cm(-3) from Ansai, Shaanxi Province as test objects, a pot experiment was conducted to study the effects of different amendment amount of soil stabilizer (EN-1 stabilizer) on the growth and root activity of ryegrass (Lolium perenne L.). Within the range of the bulk densities, the leaf chlorophyll content, root activity, root/shoot ratio, root biomass, and plant biomass of L. perenne all decreased with increasing soil bulk density, and were higher under the amendment of EN-1 stabilizer, as compared with the control. With increasing amendment amount of EN-1 stabilizer, the leaf chlorophyll content, root activity, root/shoot ratio, root biomass, and plant biomass had a trend of increased first and decreased then. Soil bulk density and stabilizer amendment amount had significant interactive effect on the root biomass and plant biomass. Overall, the values of the test indices were the highest under 1.3 g cm(-3) soil bulk density and 0.15% EN-1 stabilizer amendment amount.

  16. Allelopathic interference of alfalfa (Medicago sativa L.) genotypes to annual ryegrass (Lolium rigidum).

    PubMed

    Zubair, Hasan Muhammad; Pratley, James E; Sandral, G A; Humphries, A

    2017-07-01

    Alfalfa (Medicago sativa L.) genotypes at varying densities were investigated for allelopathic impact using annual ryegrass (Lolium rigidum) as the target species in a laboratory bioassay. Three densities (15, 30, and 50 seedlings/beaker) and 40 alfalfa genotypes were evaluated by the equal compartment agar method (ECAM). Alfalfa genotypes displayed a range of allelopathic interference in ryegrass seedlings, reducing root length from 5 to 65%. The growth of ryegrass decreased in response to increasing density of alfalfa seedlings. At the lowest density, Q75 and Titan9 were the least allelopathic genotypes. An overall inhibition index was calculated to rank each alfalfa genotype. Reduction in seed germination of annual ryegrass occurred in the presence of several alfalfa genotypes including Force 10, Haymaster7 and SARDI Five. A comprehensive metabolomic analysis using Quadruple Time of Flight (Q-TOF), was conducted to compare six alfalfa genotypes. Variation in chemical compounds was found between alfalfa root extracts and exudates and also between genotypes. Further individual compound assessments and quantitative study at greater chemical concentrations are needed to clarify the allelopathic activity. Considerable genetic variation exists among alfalfa genotypes for allelopathic activity creating the opportunity for its use in weed suppression through selection.

  17. Foliar zinc biofortification effects in Lolium rigidum and Trifolium subterraneum grown in cadmium-contaminated soil

    PubMed Central

    Damon, Paul; Rengel, Zed

    2017-01-01

    Zinc (Zn) is an important micronutrient that can alleviate cadmium (Cd) toxicity to plants and limit Cd entry into the food chain. However, little is known about the Zn-Cd interactions in pasture plants. We characterized the effects of foliar Zn application and Cd uptake by ryegrass (Lolium rigidum L.) and clover (Trifolium subterraneum L.) grown on Cd-contaminated soils; all combinations of foliar Zn applications (0, 0.25 and 0.5% (w/v) ZnSO4·7H2O) and soil Cd concentrations (0, 2.5 and 5 mg Cd kg-1) were tested. For both plant species, soil concentrations of DTPA-extractable Cd and Zn increased with an increase in the Cd and Zn treatments, respectively. Compared with L. rigidum, T. subterraneum accumulated, respectively, 3.3- and 4.1-fold more Cd in the 2.5-Cd and 5-Cd treatments and about 1.3-, 2.3- and 2.8-fold more Zn in the No-Zn, 0.25-Zn and 0.5-Zn treatments. Also, DTPA-Zn concentration was higher in soil after T. subterraneum than L. rigidum growth regardless of Zn applications. Foliar application of 0.25% (w/v) Zn significantly decreased the total Cd concentration in shoots of both species grown in the Cd-contaminated soil and ameliorated the adverse effects of Cd exposure on root growth, particularly in T. subterraneum. PMID:28950025

  18. Isolation of N2 -fixing rhizobacteria from Lolium perenne and evaluating their plant growth promoting traits.

    PubMed

    Castellano-Hinojosa, Antonio; Correa-Galeote, David; Palau, Josep; Bedmar, Eulogio J

    2016-01-01

    Twenty one dinitrogen (N2 )-fixing bacteria were isolated from the rhizosphere of Lolium perenne grown for more than 10 years without N-fertilization. The nearly complete sequence of the 16S rRNA gene of each strain and pairwise alignments among globally aligned sequences of the 16S rRNA genes clustered them into nine different groups. Out of the 21 strains, 11 were members of genus Bacillus, 3 belonged to each one of genera Paenibacillus and Pseudoxanthomonas, and the remaining 2 strains to each one of genera Burkholderia and Staphylococcus, respectively. A representative strain from each group contained the nifH gene and fixed atmospheric N2 as determined by the acetylene-dependent ethylene production assay (acetylene reduction activity, ARA). The nine selected strains were also examined to behave as plant growth promoting bacteria (PGPRs) including their ability to act as a biocontrol agent. The nine representative strains produced indol acetic acid (IAA) and solubilized calcium triphosphate, five of them, strains C2, C3, C12, C15, and C16, had ACC deaminase activity, and strains C2, C3, C4, C12, C16, and C17 produced siderophores. Strains C13, C16, and C17 had the capability to control growth of the pathogen Fusarium oxysporum mycelial growth in vitro. PCA analysis of determined PGPR properties showed that ARA, ACC deaminase activity, and siderophore production were the most valuable as they had the maximal contribution to the total variance.

  19. Selection for low dormancy in annual ryegrass (Lolium rigidum) seeds results in high constitutive expression of a glucose-responsive α-amylase isoform.

    PubMed

    Goggin, Danica E; Powles, Stephen B

    2012-12-01

    α-Amylase in grass caryopses (seeds) is usually expressed upon commencement of germination and is rarely seen in dry, mature seeds. A heat-stable α-amylase activity was unexpectedly selected for expression in dry annual ryegrass (Lolium rigidum) seeds during targeted selection for low primary dormancy. The aim of this study was to characterize this constitutive activity biochemically and determine if its presence conferred insensitivity to the germination inhibitors abscisic acid and benzoxazolinone. α-Amylase activity in developing, mature and germinating seeds from the selected (low-dormancy) and a field-collected (dormant) population was characterized by native activity PAGE. The response of seed germination and α-amylase activity to abscisic acid and benzoxazolinone was assessed. Using an alginate affinity matrix, α-amylase was purified from dry and germinating seeds for analysis of its enzymatic properties. The constitutive α-amylase activity appeared late during seed development and was mainly localized in the aleurone; in germinating seeds, this activity was responsive to both glucose and gibberellin. It migrated differently on native PAGE compared with the major activities in germinating seeds of the dormant population, but the enzymatic properties of α-amylase purified from the low-dormancy and dormant seeds were largely indistinguishable. Seed imbibition on benzoxazolinone had little effect on the low-dormancy seeds but greatly inhibited germination and α-amylase activity in the dormant population. The constitutive α-amylase activity in annual ryegrass seeds selected for low dormancy is electrophoretically different from that in germinating seeds and its presence confers insensitivity to benzoxazolinone. The concurrent selection of low dormancy and constitutive α-amylase activity may help to enhance seedling establishment under competitive conditions.

  20. Selection for low dormancy in annual ryegrass (Lolium rigidum) seeds results in high constitutive expression of a glucose-responsive α-amylase isoform

    PubMed Central

    Goggin, Danica E.; Powles, Stephen B.

    2012-01-01

    Background and Aims α-Amylase in grass caryopses (seeds) is usually expressed upon commencement of germination and is rarely seen in dry, mature seeds. A heat-stable α-amylase activity was unexpectedly selected for expression in dry annual ryegrass (Lolium rigidum) seeds during targeted selection for low primary dormancy. The aim of this study was to characterize this constitutive activity biochemically and determine if its presence conferred insensitivity to the germination inhibitors abscisic acid and benzoxazolinone. Methods α-Amylase activity in developing, mature and germinating seeds from the selected (low-dormancy) and a field-collected (dormant) population was characterized by native activity PAGE. The response of seed germination and α-amylase activity to abscisic acid and benzoxazolinone was assessed. Using an alginate affinity matrix, α-amylase was purified from dry and germinating seeds for analysis of its enzymatic properties. Key Results The constitutive α-amylase activity appeared late during seed development and was mainly localized in the aleurone; in germinating seeds, this activity was responsive to both glucose and gibberellin. It migrated differently on native PAGE compared with the major activities in germinating seeds of the dormant population, but the enzymatic properties of α-amylase purified from the low-dormancy and dormant seeds were largely indistinguishable. Seed imbibition on benzoxazolinone had little effect on the low-dormancy seeds but greatly inhibited germination and α-amylase activity in the dormant population. Conclusions The constitutive α-amylase activity in annual ryegrass seeds selected for low dormancy is electrophoretically different from that in germinating seeds and its presence confers insensitivity to benzoxazolinone. The concurrent selection of low dormancy and constitutive α-amylase activity may help to enhance seedling establishment under competitive conditions. PMID:23002268

  1. Development of molecular markers, based on chloroplast and ribosomal DNA regions, to discriminate three popular medicinal plant species, Cynanchum wilfordii, Cynanchum auriculatum, and Polygonum multiflorum.

    PubMed

    Han, Eun-Heui; Cho, KyeMan; Goo, YoungMin; Kim, ManBae; Shin, Young-Wook; Kim, Yun-Hee; Lee, Shin-Woo

    2016-04-01

    Identification of plant species is important for standardizing herbal medicine. Cynanchum wilfordii (Baekshuoh in Korean) and Polygonum multiflorum (Hashuoh in Korean) are important oriental medicinal herbs in Korea, Japan, and China. Cynanchum auriculatum is a faster growing and more productive plant than C. wilfordii; and, it is not recognized as a medicinal plant in the Korean Pharmacopoeia. C. wilfordii, P. multiflorum, and C. auriculatum are often misidentified in the Korean herbal medicine marketplace due to their morphological similarities and similar names. In this study, we investigated molecular authentication of these three medicinal plants using DNA sequences in the TrnL-F chloroplast intergenic region. Specific species identification was achieved by detecting allelic variations of single nucleotide polymorphisms (SNPs) using amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and high resolution melting curve analysis. Our results demonstrate that the intraspecific genetic distance between C. wilfordii and C. auriculatum is relatively low. We also developed a quantitative PCR assay using species-specific TrnL-F primers, which allowed us to estimate the ratio of C. wilfordii and C. auriculatum using varying ratios of mixed genomic DNA template from the two species. Additionally, to identify species in hybrid plants produced by cross-fertilization, we analyzed nuclear ribosomal DNA internal transcribed spacer regions in C. wilfordii and C. auriculatum by ARMS-PCR. Our results indicate that SNP-based molecular markers, usable to barcode tools could provide efficient and rapid authentication of these closely related medicinal plant species, and will be useful for preventing the distribution of products contaminated with adulterants.

  2. Changes in Lolium perenne transcriptome during cold acclimation in two genotypes adapted to different climatic conditions.

    PubMed

    Abeynayake, Shamila Weerakoon; Byrne, Stephen; Nagy, Istvan; Jonavičienė, Kristina; Etzerodt, Thomas Povl; Boelt, Birte; Asp, Torben

    2015-10-17

    Activation of numerous protective mechanisms during cold acclimation is important for the acquisition of freezing tolerance in perennial ryegrass (Lolium perenne L.). To elucidate the molecular mechanisms of cold acclimation in two genotypes ('Veyo' and 'Falster') of perennial ryegrass from distinct geographical origins, we performed transcriptome profiling during cold acclimation using RNA-Seq. We cold-acclimated plants from both genotypes in controlled conditions for a period of 17 days and isolated Total RNA at various time points for high throughput sequencing using Illumina technology. RNA-seq reads were aligned to genotype specific references to identify transcripts with significant changes in expression during cold acclimation. The genes induced were involved in protective mechanisms such as cell response to abiotic stimulus, signal transduction, redox homeostasis, plasma membrane and cell wall modifications, and carbohydrate metabolism in both genotypes. 'Falster' genotype, adapted to cold climates, showed a stronger transcriptional differentiation during cold acclimation, and more differentially expressed transcripts related to stress, signal transduction, response to abiotic stimulus, and metabolic processes compared to 'Veyo'. 'Falster' genotype also showed an induction of more transcripts with sequence homology to fructosyltransferase genes (FTs) and a higher fold induction of fructan in response to low-temperature stress. The circadian rhythm network was perturbed in the 'Veyo' genotype adapted to warmer climates. In this study, the differentially expressed genes during cold acclimation, potentially involved in numerous protective mechanisms, were identified in two genotypes of perennial ryegrass from distinct geographical origins. The observation that the circadian rhythm network was perturbed in 'Veyo' during cold acclimation may point to a low adaptability of 'Veyo' to low temperature stresses. This study also revealed the transcriptional mechanisms

  3. Persistence of endophytic fungi in cultivars of Lolium perenne grown from seeds stored for 22 years.

    PubMed

    Cheplick, Gregory P

    2017-04-01

    Genetic resources for forage crops often consist of seeds of specific species and cultivars in cold storage for future use in breeding and selection programs. Temperate grasses such as Lolium perenne, used worldwide for forage and turf, produce seeds commonly infected by hyphae of an endophytic fungus (Epichloë festucae var. lolii). This research determined whether endophytes could persist and infect seedlings of L. perenne emerging from seeds stored for over two decades. Endophyte-infected seeds (>90% infected) of four cultivars were obtained in 1994 and stored dry in plastic bags at 4°C. Seed germination was tested after 12 yr (for two cultivars) and after 18 and 22 yr (for all cultivars). Seedling leaf sheaths were excised, stained, and examined at 400× for endophytic hyphae to quantify infection frequency (% plants infected) and intensity (mean number of endophytic hyphae per field of view). Seed germination after 22 yr depended on cultivar, ranging from 53 to 78%. Between 58 and 73% of plants grown from seeds stored for 22 yr still contained viable endophytic hyphae. Infection intensity remained at original levels for 18 yr in one cultivar; however, in all cultivars, infection intensity declined significantly between 18 and 22 yr. Persistence of the grass seed-endophyte symbiosis for over 20 yr surpasses all prior records of endophyte longevity within stored seeds. Storage of germplasm of cool-season grass cultivars that contain potentially beneficial fungal endophytes should be possible for several decades under dry, cold conditions. © 2017 Botanical Society of America.

  4. Pollen-Mediated Movement of Herbicide Resistance Genes in Lolium rigidum

    PubMed Central

    Loureiro, Iñigo; Escorial, María-Concepción; Chueca, María-Cristina

    2016-01-01

    The transfer of herbicide resistance genes by pollen is a major concern in cross-pollinated species such as annual ryegrass (Lolium rigidum). A two-year study was conducted in the greenhouse, under favorable conditions for pollination, to generate information on potential maximum cross-pollination. This maximum cross-pollination rate was 56.1%. A three-year field trial was also conducted to study the cross-pollination rates in terms of distance and orientation to an herbicide-resistant pollen source. Under field conditions, cross-pollination rates varied from 5.5% to 11.6% in plants adjacent to the pollen source and decreased with increasing distances (1.5 to 8.9% at 15 m distance and up to 4.1% at 25 m in the downwind direction). Environmental conditions influenced the cross-pollination both under greenhouse and field conditions. Data were fit to an exponential decay model to predict gene flow at increasing distances. This model predicted an average gene flow of 7.1% when the pollen donor and recipient plants were at 0 m distance from each other. Pollen-mediated gene flow declined by 50% at 16.7 m from the pollen source, yet under downwind conditions gene flow of 5.2% was predicted at 25 m, the farthest distance studied. Knowledge of cross-pollination rates will be useful for assessing the spread of herbicide resistance genes in L. rigidum and in developing appropriate strategies for its mitigation. PMID:27336441

  5. Immunochemical studies of Lolium perenne (rye grass) pollen allergens, Lol p I, II, and III.

    PubMed

    Ansari, A A; Kihara, T K; Marsh, D G

    1987-12-15

    It was reported earlier that human immune responses to three perennial rye grass (Lolium perenne) pollen allergens, Lol p I, II, and III, are associated with histocompatibility leukocyte antigen (HLA)-DR3. Rye-allergic people are often concordantly sensitive to all three of these allergens. Since earlier studies suggested that these antigens are non-cross-reactive, their immunologic relatedness by double antibody radioimmunoassay (DARIA) was studied in order to understand further the immunochemical basis for the concordant recognition of the three allergens. Direct binding DARIA studies were performed with human sera from 189 allergic subjects. Inhibition DARIA studies were carried out with 17 human sera from grass-allergic patients who were on grass immunotherapy, one goat anti-serum, and six rabbit antisera. None of the sera detected any significant degree of two-way cross-reactivity between Lol p I and II, or between Lol p I and III. However, the degree of two-way cross-reactivity between Lol p II and III exhibited by individual human and animal antisera varied between undetectable and 100%. In general, the degree of cross-reactivity between Lol p II and III was higher among human sera than among animal sera. Taken together with earlier findings that antibody responses to Lol p I, II and III are associated with HLA-HDR3, and that most Lol p II and III responders are also Lol p I responders, but not vice versa, our present results suggest the following: the HLA-DR3-encoded Ia molecule recognizes a similar immunodominant Ia recognition site (agretope) shared between Lol p I and Lol p II and/or III; in addition, Lol p I appears to contain unique Ia recognition site(s) not present in Lol p II and III. However, further epitope analyses are required to investigate these possibilities.

  6. Cloning, expression, and immunological characterization of recombinant Lolium perenne allergen Lol p II.

    PubMed

    Sidoli, A; Tamborini, E; Giuntini, I; Levi, S; Volonté, G; Paini, C; De Lalla, C; Siccardi, A G; Baralle, F E; Galliani, S

    1993-10-15

    The molecular cloning of the cDNA encoding for an isoallergenic form of Lol p II, a major rye grass (Lolium perenne) pollen allergen, was performed by polymerase chain reaction amplification on mRNA extracted from pollen. The amino acid sequence derived from the cDNA was truncated by 4 and 5 residues at the NH2- and COOH-terminal ends, respectively, and differed only in one position from that previously reported. This cDNA was expressed in Escherichia coli by fusion to the carboxyl terminus of the human ferritin H-chain. The molecule was produced in high yields as a soluble protein and was easily purified. The protein retains the multimeric quaternary structure of ferritin, and it exposes on the surface the allergenic moiety, which can be recognized in Western blotting and in enzyme-linked immunosorbent assay experiments by specific IgE from allergic patients. The recombinant allergen was used to analyze the sera of 26 patients allergic to L. perenne compared with control sera. The results were in good agreement with the values obtained with the radioallergosorbent test assay. In addition, histamine release experiments in whole blood from an allergic patient and skin prick tests showed that the recombinant allergen retains some of the biological properties of the natural compound. These findings indicate that the availability of homogeneous recombinant allergens may be useful for the development of more specific diagnostic and therapeutic procedures. Moreover, this expression system may be of more general interest for producing large amounts of soluble protein domains in E. coli.

  7. Molecular genetics of human immune responsiveness to Lolium perenne (rye) allergen, Lol p III.

    PubMed

    Ansari, A A; Freidhoff, L R; Marsh, D G

    1989-01-01

    Lol p II and III are each about 11-kD protein allergens from the pollen of Lolium perenne (rye grass). We have found that human immune responses (IgE and IgG antibodies) to both proteins are significantly associated with HLA-DR3. In addition, the two proteins are cross-reactive with the antibodies in many human sera (about 84% human sera showed the cross-reactivity). We have determined greater than 90% of the amino acid sequences of the two proteins and found that they are at least 54% homologous. Berzofsky found that 75% of the 23 known T cell sites in various proteins had an amphipathic structure. Our analysis by the same method showed that both Lol p II and III have a major region of amphipathicity (at residues 61-67, Lol p III numbering) which might contain sites for binding to an Ia molecule and a T cell receptor. This region is identical between Lol p II and III, except for an Arg-Lys substitution, and could account, in part, for the DR3 association with responsiveness to both molecules. An interesting difference between the two proteins is that immune response to Lol p III is associated with DR5 (in addition to DR3), whereas no DR5 association is found in the case of Lol p II. One possibility is that Lol p III has an additional site which binds to the DR5 Ia molecule. Lol p III indeed has a second highly amphiphathic peptide, 24-30 (Lol p III 24 R P G D T L A 30), which is different and not amphipathic in Lol p II.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. MALDI-TOF MS analysis of labile Lolium perenne major allergens in mixes.

    PubMed

    Irañeta, S G; Acosta, D M; Duran, R; Apicella, C; Orlando, U D; Seoane, M A; Alonso, A; Duschak, V G

    2008-08-01

    It is well known that allergen extracts used for specific therapy of allergic disorders are commonly stored as mixtures, causing an alteration of its stability. The aim of this report is to identify pollen allergens susceptible to degradation during storage of mixtures containing different sources of proteases in the absence of glycerol as a preserving agent. Mixes containing Lolium perenne (Lol p) pollen extract with either Aspergillus fumigatus or Periplaneta americana extracts were prepared and co-incubated for 90 days at 4 degrees C. Samples were taken off at fixed times and comparatively tested by in vitro and in vivo assays with atopic patients. Selected pollinic allergens were subjected to MALDI-TOF MS analysis. ELISA inhibition evidenced the loss of potency from ryegrass extract, and immunoblotting assays showed the degradation of specific pollinic allergens during storage of mixtures containing protease-rich sources. An in vivo intradermal skin assay confirmed the gradual loss of the biological activity of L. perenne pollen extract co-incubated with non-related protease-rich extracts in comparison with that of the control pollen extract. MALDI-TOF MS analysis allowed us to determine that Lol p 1 and Lol p 5 are susceptible to proteolysis whereas Lol p 4 was found to be resistant to degradation during storage. Lol p 1 and Lol p 5 degradation is responsible for the loss of the biological activity of L. perenne pollen extract when co-incubated with protease-rich fungal and cockroach extracts in the same vial for months in the absence of glycerol as a preserving agent. The integrity of these major allergens must be preserved to increase the vaccine stability and to assure efficacy when mixes are used for immunotherapy.

  9. UV responses of Lolium perenne raised along a latitudinal gradient across Europe: a filtration study.

    PubMed

    Comont, David; Martinez Abaigar, Javier; Albert, Andreas; Aphalo, Pedro; Causton, David R; Figueroa, Félix López; Gaberscik, Alenka; Llorens, Laura; Hauser, Marie-Theres; Jansen, Marcel A K; Kardefelt, Majlis; de la Coba Luque, Paqui; Neubert, Susanne; Núñez-Olivera, Encarnación; Olsen, Jorunn; Robson, Matthew; Schreiner, Monika; Sommaruga, Ruben; Strid, Ake; Torre, Sissel; Turunen, Minna; Veljovic-Jovanovic, Sonja; Verdaguer, Dolors; Vidovic, Marija; Wagner, Johanna; Winkler, Jana Barbro; Zipoli, Gaetano; Gwynn-Jones, Dylan

    2012-08-01

    Lolium perenne (cv. AberDart) was grown at 14 locations along a latitudinal gradient across Europe (37-68°N) to study the impact of ultraviolet radiation (UV) and climate on aboveground growth and foliar UV-B absorbing compounds. At each location, plants were grown outdoors for 5 weeks in a replicated UV-B filtration experiment consisting of open, UV-B transparent (cellulose diacetate) and UV-B opaque (polyester) environments. Fourier transform-infrared spectroscopy was used to compare plant metabolite profiles in relation to treatment and location. UV radiation and climatic parameters were determined for each location from online sources and the data were assessed using a combination of anova and multiple regression analyses. Most of the variation in growth between the locations was attributable to the combination of climatic parameters, with minimum temperature identified as an important growth constraint. However, no single environmental parameter could consistently account for the variability in plant growth. Concentrations of foliar UV-B absorbing compounds showed a positive trend with solar UV across the latitudinal gradient; however, this relationship was not consistent in all treatments. The most striking experimental outcome from this study was the effect of presence or absence of filtration frames on UV-absorbing compounds. Overall, the study demonstrates the value of an European approach in studying the impacts of natural UV across a large latitudinal gradient. We have shown the feasibility of coordinated UV filtration at multiple sites but have also highlighted the need for open controls and careful interpretation of plant responses. Copyright © Physiologia Plantarum 2012.

  10. Recovery from drought stress in Lolium perenne (Poaceae): are fungal endophytes detrimental?

    PubMed

    Cheplick, Gregory P

    2004-12-01

    Perennial ryegrass (Lolium perenne) is a cool-season, perennial species widely used for forage and turf. It is often infected by a clandestine, endophytic fungus (Neotyphodium lolii) that has the potential to affect host growth responses to abiotically stressful conditions. In some species, the grass-endophyte symbiosis is mutualistic, but the relationship is reported to be contingent on environmental conditions and host genotype in L. perenne. The objective of this research was to determine the potential effects of endophyte infection on recovery from severe drought stress in variable genotypes of a perennial ryegrass cultivar. Sixteen infected (+E) and 16 uninfected (-E) ramets were planted in the greenhouse for each of 10 ryegrass genotypes. Eight +E and eight -E plants per genotype were exposed to three sequential droughts where water was withheld for 11-14 d, resulting in <5% soil moisture; the others (control) were watered as needed. Response variables were tiller numbers 1 wk and 4 wk after drought, and leaf area and dry mass of shoots and roots 7 wk after drought. In both control and drought, -E plants had more tillers, and greater leaf area and total mass, than +E plants, suggesting a detrimental effect of endophytic fungi. Fungal hyphae survived the drought and were abundant in post-drought, +E plants. The effects of endophytes were specific for particular host genotypes, as exemplified by significant genotype × endophyte interactions. Root : shoot ratio and percent of mass allocated to tiller bases (a rough measure of resource storage) showed genotype × endophyte × drought interactions. There was plasticity for root : shoot ratio and genetic variation in the ability to restore root growth during recovery from drought. For 7 of 10 genotypes, -E plants showed an equal or greater allocation to tiller bases than +E plants following drought recovery, illustrating a cost to endophyte infection for some genotypes. The symbiotic relationship between L

  11. Phytostabilization of copper mine tailings with biosolids: implications for metal uptake and productivity of Lolium perenne.

    PubMed

    Santibáñez, Claudia; Verdugo, Cesar; Ginocchio, Rosanna

    2008-05-20

    A greenhouse pot experiment was conducted to evaluate the feasibility of using biosolids and Lolium perenne for the phytostabilization of copper mine tailings and to evaluate the patterns of metal accumulation and translocation in plants. Biosolids were applied either on the surface or mixed with the tailings at rates of 0, 6, and 12% w/w. All pots were seeded with L. perenne and after six months, the plants were harvested and separated into roots and shoots for metal concentrations analyses as well as some physiological characteristics of the plants. In order to correlate the metal content in plant tissues with some chemical properties, the pore-water of the substrates was analyzed for metals, pH and dissolved organic carbon. Results showed that biosolids application increased the dry biomass production of L. perenne and the shoot concentrations of N and chlorophyll. On the other hand, biosolids increased the concentration of Cu and Zn in the pore-water and in plant tissues. Despite this, there were no evident symptoms of phytotoxicity and the concentration of metals was within the normal ranges described for plants and below the maximum tolerable level for animals. In addition, plant tissue analysis showed that the application of biosolids could significantly reduce Mo uptake and shoot accumulation in plants. The metals were taken up by plants in the following order: Cu>Zn>Mo>Cd. The distribution patterns of metals in plants showed that metals were mainly accumulated in the roots and only a small amount of them were transported to the shoots. These results suggest that mixed application of biosolids (6%) and the use of L. perenne could be appropriate for use in programs of phytostabilization of copper mine tailings. However, these results should be tested under field conditions in order to confirm their efficacy under semi-arid Mediterranean climate conditions.

  12. Lambs Fed Fresh Winter Forage Rape (Brassica napus L.) Emit Less Methane than Those Fed Perennial Ryegrass (Lolium perenne L.), and Possible Mechanisms behind the Difference

    PubMed Central

    Sun, Xuezhao; Henderson, Gemma; Cox, Faith; Molano, German; Harrison, Scott J.; Luo, Dongwen; Janssen, Peter H.; Pacheco, David

    2015-01-01

    The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.). The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks). The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems. PMID:25803688

  13. Lambs fed fresh winter forage rape (Brassica napus L.) emit less methane than those fed perennial ryegrass (Lolium perenne L.), and possible mechanisms behind the difference.

    PubMed

    Sun, Xuezhao; Henderson, Gemma; Cox, Faith; Molano, German; Harrison, Scott J; Luo, Dongwen; Janssen, Peter H; Pacheco, David

    2015-01-01

    The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.). The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks). The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems.

  14. Ergot alkaloid intoxication in perennial ryegrass (Lolium perenne): an emerging animal health concern in Ireland?

    PubMed Central

    2014-01-01

    Four primary mycotoxicosis have been reported in livestock caused by fungal infections of grasses or cereals by members of the Clavicipitaceae family. Ergotism (generally associated with grasses, rye, triticale and other grains) and fescue toxicosis (associated with tall fescue grass, Festuca arundinacea) are both caused by ergot alkaloids, and referred to as ‘ergot alkaloid intoxication’. Ryegrass staggers (associated with perennial ryegrass Lolium perenne) is due to intoxication with an indole-diperpene, Lolitrem B, and metabolites. Fescue-associated oedema, recently described in Australia, may be associated with a pyrrolizidine alkaloid, N-acetyl norloline. Ergotism, caused by the fungus Claviceps purpurea, is visible and infects the outside of the plant seed. Fescue toxicosis and ryegrass staggers are caused by Neotyphodium coenophalium and N. lolii, respectively. Fescue-associated oedema has been associated with tall fescue varieties infected with a specific strain of N. coenophialum (AR542, Max P or Max Q). The name Neotyphodium refers to asexual derivatives of Epichloë spp., which have collectively been termed the epichloë fungi. These fungi exist symbiotically within the grass and are invisible to the naked eye. The primary toxicological effect of ergot alkaloid involves vasoconstriction and/or hypoprolactinaemia. Ingestion of ergot alkaloid by livestock can cause a range of effects, including poor weight gain, reduced fertility, hyperthermia, convulsions, gangrene of the extremities, and death. To date there are no published reports, either internationally or nationally, reporting ergot alkaloid intoxication specifically associated with perennial ryegrass endophytes. However, unpublished reports from the Irish Equine Centre have identified a potential emerging problem of ergot alkaloid intoxication with respect to equines and bovines, on primarily perennial ryegrass-based diets. Ergovaline has been isolated in varying concentrations in the herbage of

  15. Ergot alkaloid intoxication in perennial ryegrass (Lolium perenne): an emerging animal health concern in Ireland?

    PubMed

    Canty, Mary J; Fogarty, Ursula; Sheridan, Michael K; Ensley, Steve M; Schrunk, Dwayne E; More, Simon J

    2014-01-01

    Four primary mycotoxicosis have been reported in livestock caused by fungal infections of grasses or cereals by members of the Clavicipitaceae family. Ergotism (generally associated with grasses, rye, triticale and other grains) and fescue toxicosis (associated with tall fescue grass, Festuca arundinacea) are both caused by ergot alkaloids, and referred to as 'ergot alkaloid intoxication'. Ryegrass staggers (associated with perennial ryegrass Lolium perenne) is due to intoxication with an indole-diperpene, Lolitrem B, and metabolites. Fescue-associated oedema, recently described in Australia, may be associated with a pyrrolizidine alkaloid, N-acetyl norloline. Ergotism, caused by the fungus Claviceps purpurea, is visible and infects the outside of the plant seed. Fescue toxicosis and ryegrass staggers are caused by Neotyphodium coenophalium and N. lolii, respectively. Fescue-associated oedema has been associated with tall fescue varieties infected with a specific strain of N. coenophialum (AR542, Max P or Max Q). The name Neotyphodium refers to asexual derivatives of Epichloë spp., which have collectively been termed the epichloë fungi. These fungi exist symbiotically within the grass and are invisible to the naked eye. The primary toxicological effect of ergot alkaloid involves vasoconstriction and/or hypoprolactinaemia. Ingestion of ergot alkaloid by livestock can cause a range of effects, including poor weight gain, reduced fertility, hyperthermia, convulsions, gangrene of the extremities, and death. To date there are no published reports, either internationally or nationally, reporting ergot alkaloid intoxication specifically associated with perennial ryegrass endophytes. However, unpublished reports from the Irish Equine Centre have identified a potential emerging problem of ergot alkaloid intoxication with respect to equines and bovines, on primarily perennial ryegrass-based diets. Ergovaline has been isolated in varying concentrations in the herbage of a

  16. Physiological and biochemical responses to manganese toxicity in ryegrass (Lolium perenne L.) genotypes.

    PubMed

    Inostroza-Blancheteau, Claudio; Reyes-Díaz, Marjorie; Berríos, Graciela; Rodrigues-Salvador, Acácio; Nunes-Nesi, Adriano; Deppe, Mariana; Demanet, Rolando; Rengel, Zed; Alberdi, Miren

    2017-04-01

    We studied resistance to manganese (Mn) toxicity under acidic conditions and its relationship with nutrients such as calcium (Ca) and magnesium (Mg) in new perennial ryegrass (Lolium perenne L.) genotypes (One-50, Banquet-II and Halo-AR1) introduced in southern Chile, using the Nui genotype as the reference. Plants were grown in nutrient solution at increased Mn concentrations (0-750 μM) at pH 4.8, and physiological and biochemical features were determined. Under higher Mn concentration, the One-50 genotype had a significantly lower relative growth rate (RGR) of shoots and roots, whereas in the other cultivars this parameter did not change under variable Mn treatments. Increasing the Mn concentration led to an increased Mn concentration in roots and shoots, with Banquet-II and Halo-AR1 having higher Mn in roots than shoots. Shoot Mg and Ca concentrations in all genotypes (except Banquet-II) decreased concomitantly with increasing Mn applications. In contrast to the other genotypes, Banquet-II and Halo-AR1 maintained their net CO2 assimilation rate regardless of Mn treatment, whereas the chlorophyll concentration decreased in all genotypes with the exception of Banquet-II. In addition, lipid peroxidation in Banquet-II roots increased at 150 μM Mn, but decreased at higher Mn concentrations. This decrease was associated with an increase in antioxidant capacity as well as total phenol concentration. Banquet-II and Halo-AR1 appear to be the most Mn-resistant genotypes based on RGR and CO2 assimilation rate. In addition, Mn excess provoked a strong decrease in Ca and Mg concentrations in shoots of the Mn-sensitive genotype, whereas only slight variations in the Mn-resistant genotype were noted. When other evaluated parameters were taken into account, we concluded that among the perennial ryegrass genotypes introduced recently into southern Chile Banquet-II appears to be the most Mn-resistant, followed by Halo-AR1, with One-50 being the most sensitive.

  17. [The toxic and protective effects of Polygonum multiflorum on normal and liver injured rats based on the symptom-based prescription theory].

    PubMed

    Pang, Jing-yao; Bai, Zhao-fang; Niu, Ming; Tu, Can; Ma, Zhi-jie; Zhao, Yan-ling; Zhao, Kui-jun; You, Yun; Wang, Jia-bo; Xiao, Xiao-he

    2015-08-01

    The dosage-efficacy/toxicity relationship of the 50% alcohol extracts of Polygonum multiflorum was comparatively investigated on either normal or CCl4-induced chronic liver injury rats, by determining the general condition, serum biochemical indices and liver histopathology, coupled with the factor analysis. The dosages were 10 and 20 g raw materials per kg body weight. Compared with the normal control group, the normal high dose group showed significant increases of the serum alanine transaminase (ALT), total bilirubin (TBIL), high mobility group box 1 (HMGB-1) and interleukin-1β (IL-1β) (P < 0.05 or P < 0.01), as well the frequent incidences of inflammatory cell infiltration, hepatic sinus enlargement and fiber stripes formation in histopathological sections. Compared with the model control group, the model low dose group showed significant declines of serum ALT, aspartate transaminase (AST) and total bile acid (TBA) (P < 0.05), as well the alleviation of vacuoles of hepatocytes, but no amelioration of the inflammatory cell infiltration and fibrous tissue hyperplasia; moreover, the model high dose group showed significant degeneration declines of serum HMGB-1, tumor necrosis factor-α (TNF-α) and IL-1β (P < 0.05, P < 0.01), as well the evident alleviation of vacuoles degeneration of hepatocytes, inflammatory cells infiltration and fibrosis degree. The factor analysis showed that the low dosage treatment had almost neither injuring effect on the normal rats nor protective effect on the model rats; while the high dosage treatment showed observable injuring effect on the normal rats, expressed by the significant increases of the factor-1 (HMGB-1, TNF-α and IL-1β as the main contributors) and factor-2 (TBIL, ALT and TBA as the main contributors) relative to the normal control group. The liver protective effect of the high dosage treatment could be observed with the significant reduction of the factor-1, indicating the effective alleviation of the expression of

  18. Metabolomic Study on Idiosyncratic Liver Injury Induced by Different Extracts of Polygonum multiflorum in Rats Integrated with Pattern Recognition and Enriched Pathways Analysis

    PubMed Central

    Li, Chun-Yu; Tu, Can; Gao, Dan; Wang, Rui-Lin; Zhang, Hai-Zhu; Niu, Ming; Li, Rui-Yu; Zhang, Cong-En; Li, Rui-Sheng; Xiao, Xiao-He; Yang, Mei-Hua; Wang, Jia-Bo

    2016-01-01

    Currently, numerous liver injury cases related to a famous Chinese herb- Polygonum Multiflorum (Heshouwu in Chinese) have attracted great attention in many countries. Our previous work showed that Heshouwu-induced hepatotoxicity belonged to idiosyncratic drug-induced liver injury (IDILI). Unfortunately, the components and mechanisms attributed to IDILI of Heshouwu are difficult to determine and thus remain unknown. Attempts to explore puzzles, we prepared the chloroform (CH)-, ethyl acetate (EA)-, and residue (RE) extracts of Heshouwu to investigate IDILI constituents and underlying mechanisms, using biochemistry, histopathology, and metabolomics examinations. The results showed that co-treatment with non-toxic dose of lipopolysaccharide (LPS) and EA extract could result in evident liver injury, indicated by the significant elevation of plasma alanine aminotransferase and aspartate aminotransferase activities, as well as obvious liver histologic damage; whereas other two separated fractions, CH and RE extracts, failed to induce observable liver injury. Furthermore, 21 potential metabolomic biomarkers that differentially expressed in LPS/EA group compared with other groups without liver injury were identified by untargeted metabolomics, mainly involved two pathways: tricarboxylic acid cycle and sphingolipid metabolism. This work illustrated EA extract had close association with the idiosyncratic hepatotoxicity of Heshouwu and provided a metabolomic insight into IDILI of different extracts from Heshouwu. PMID:28018221

  19. Evidence chain-based causality identification in herb-induced liver injury: exemplification of a well-known liver-restorative herb Polygonum multiflorum.

    PubMed

    Wang, Jiabo; Ma, Zhijie; Niu, Ming; Zhu, Yun; Liang, Qingsheng; Zhao, Yanling; Song, Jingyuan; Bai, Zhaofang; Zhang, Yaming; Zhang, Ping; Li, Na; Meng, Yakun; Li, Qi; Qin, Lushan; Teng, Guangju; Cao, Junling; Li, Baosen; Chen, Shilin; Li, Yonggang; Zou, Zhengsheng; Zhou, Honghao; Xiao, Xiaohe

    2015-12-01

    Herbal medicines have recently been recognized as the second most common cause of drug-induced liver injury (DILI) in the United States. However, reliable methods to identify the DILI causality of some herbs, such as Heshouwu (dried root of Polygonum multiflorum), remain lacking. In this study, a total of 12 307 inpatients with liver dysfunction and 147 literature-reported cases of Heshouwu DILI were screened. A general algorithm indicated that only 22.5% (9/40) and 30.6% (45/147) of all hospitalization and literature case reports, respectively, demonstrate the high probability of DILI causality of Heshouwu. By contrast, 95% (19/20) of all cases prospectively investigated by pharmacognosy, phytochemistry, and metabolomic tests exhibited highly probable causality, including a patient who was previously incorrectly attributed and a case that was excluded from Heshouwu causality by pharmacognostic evidence. Toxin (heavy metals, pesticides, and mycotoxins) contamination was also excluded from Heshouwu DILI causality. The objectivity of these screening methods for Heshouwu DILI diagnosis addresses safety concerns regarding stilbene-containing herbal medicines and dietary supplements.

  20. Fragments of the key flowering gene GIGANTEA are associated with helitron-type sequences in the Pooideae grass Lolium perenne

    PubMed Central

    Langdon, Tim; Thomas, Ann; Huang, Lin; Farrar, Kerrie; King, Julie; Armstead, Ian

    2009-01-01

    Background Helitrons are a class of transposable elements which have been identified in a number of species of plants, animals and fungi. They are unique in their proposed rolling-circle mode of replication, have a highly variable copy-number and have been implicated in the restructuring of coding sequences both by their insertion into existing genes and by their incorporation of transcriptionally competent gene fragments. Helitron discovery depends on identifying associated DNA signature sequences and comprehensive evaluation of helitron contribution to a particular genome requires detailed computational analysis of whole genome sequence. Therefore, the role which helitrons have played in modelling non-model plant genomes is largely unknown. Results Cloning of the flowering gene GIGANTEA (GI) from a BAC library of the Pooideae grass Lolium perenne (perennial ryegrass) identified the target gene and several GI pseudogene fragments spanning the first five exons. Analysis of genomic sequence 5' and 3' of one these GI fragments revealed motifs consistent with helitron-type transposon insertion, specifically a putative 5'-A↓T-3' insertion site containing 5'-TC and CTAG-3' borders with a sub-terminal 16 bp hairpin. Screening of a BAC library of the closely related grass species Festuca pratensis (meadow fescue) indicated similar helitron-associated GI fragments present in this genome, as well as non-helitron associated GI fragments derived from the same region of GI. In order to investigate the possible extent of ancestral helitron-activity in L. perenne, a methylation-filtered GeneThresher® genomic library developed from this species was screened for potential helitron 3' hairpin sequences associated with a 3'-CTRR motif. This identified 7 potential helitron hairpin-types present between at least 9 and 51 times within the L. perenne methylation-filtered library. Conclusion This represents evidence for a possible ancestral role for helitrons in modelling the genomes

  1. Variability of ribosomal DNA sites in Festuca pratensis, Lolium perenne, and their intergeneric hybrids, revealed by FISH and GISH.

    PubMed

    Ksiazczyk, T; Taciak, M; Zwierzykowski, Z

    2010-01-01

    This study focuses on the variability of chromosomal location and number of ribosomal DNA (rDNA) sites in some diploid and autotetraploid Festuca pratensis and Lolium perenne cultivars, as well as on identification of rDNA-bearing chromosomes in their triploid and tetraploid F. pratensis × L. perenne hybrids. The rDNA loci were mapped using fluorescence in situ hybridization (FISH) with 5S and 25S rDNA probes, and the origin of parental genomes was verified by genomic in situ hybridization (GISH) with L. perenne genomic DNA as a probe, and F. pratensis genomic DNA as a block. FISH detected variation in the number and chromosomal location of both 5S and 45S rDNA sites. In F. pratensis mostly additional signals of 5S rDNA loci occurred, as compared with standard F. pratensis karyotypes. Losses of 45S rDNA loci were more frequent in L. perenne cultivars and intergeneric hybrids. Comparison of the F. pratensis and L. perenne genomes approved a higher number of rDNA sites as well as variation in chromosomal rDNA location in L. perenne. A greater instability of F. pratensis-genome-like and L. perenne-genome-like chromosomes in tetraploid hybrids was revealed, indicating gains and losses of rDNA loci, respectively. Our data indicate that the rDNA loci physically mapped on chromosomes 2 and 3 in F. pratensis and on chromosome 3 in L. perenne are useful markers for these chromosomes in intergeneric Festuca × Lolium hybrids.

  2. Integrated chemometric fingerprints of antioxidant activities and HPLC-DAD-CL for assessing the quality of the processed roots of Polygonum multiflorum Thunb. (Heshouwu).

    PubMed

    Chen, Hai Fang; Chen, You Hua; Liu, Chun Hua; Wang, Lu; Chen, Xi; Yu, Bo Yang; Qi, Jin

    2016-01-01

    The processed roots of Polygonum multiflorum Thunb. (Heshouwu; processed HSW) are commonly used in anti-aging medicine. Few reports have combined chemical profiles with bioactivity to evaluate the quality of the processed HSW. This study aims to integrate chemometric fingerprints of antioxidant activities and high-performance liquid chromatography-diode array detection-chemiluminescence (HPLC-DAD-CL) to assess the quality of processed HSW. An online HPLC-DAD-CL based on the three reactive oxygen species (ROS), superoxide anion, hydrogen peroxide, and peroxynitriteanion, was developed to screen the potential anti-aging constituents for a comprehensive quality evaluation of processed HSW. Additionally, antioxidant-activity-integrated fingerprints were constructed and hierarchical cluster analysis and principal component analysis were used to evaluate the variations among 14 batches of processed HSW samples purchased from drug stores in different habitats. Fourteen batches of processed HSW samples were highly similar and classified into two clusters using hierarchical cluster analysis. Twelve active compounds exhibited antioxidant activity on the ROS with different degrees of sensitivity that constituted specific fingerprints. Among them, protocatechuic acid, catechin, trans-2,3,5,4'-tetrahydroxy-stilbene-2-O-β-d-glucoside, 2,3,5, 4'-tetrahydroxy-stilbene-2-O-β-d-(2''-galloyl)-glucoside, torachrysone-8-O-glucoside, and emodin-8-O-β-d-glucoside exerted relatively large influences on the differences between processed HSW samples. Our study established the antioxidative activity-integrated fingerprint for processed HSW and achieved a screening of the potential anti-aging constituents using the online HPLC-DAD-CL method with H2O2, O2 (•-), and ONOO(-)scavenging experiments.

  3. Evidence, Mechanism and Alternative Chemical Seedbank-Level Control of Glyphosate Resistance of a Rigid Ryegrass (Lolium rigidum) Biotype from Southern Spain.

    PubMed

    Fernández-Moreno, Pablo T; Bastida, Fernando; De Prado, Rafael

    2017-01-01

    Rigid ryegrass (Lolium rigidum) is one of the most troublesome weeds in different crops in the Mediterranean region. A rigid ryegrass biotype from an olive grove in Jaén province (Andalusía, southern Spain), potentially resistant to glyphosate (RG), was tested for its resistance level through dose-response assays using a susceptible biotype (SG). To test the hypothesis of a non-target-site-based resistance, as point mutations are far less common mechanisms of glyphosate resistance, studies were also conducted to elucidate whether resistance was associated with biochemical, metabolism, molecular and/or physiological mechanisms. Alternative herbicide-based control options, including single-herbicide or herbicide mixtures with glyphosate, applied at seedling, tillering or full heading stages, were tested in field experiments for 2 years for their efficacy against rigid ryegrass plants and their effects on the soil seed bank. Resistance levels of the RG biotype were 23- (LD50) and 7-fold (GR50) higher compared to the SG biotype. The SG biotype exhibited a significantly greater shikimic acid accumulation than the RG one. At 96 HAT, 58 and 89% of applied (14)C-glyphosate was up taken by leaves of RG and SG biotype plants, respectively, and, at this time, a significantly higher proportion of the glyphosate taken up by the treated leaf remained in its tissue in RG plants compared to the SG ones. The RG biotype did not reveal any point mutation in the glyphosate target site EPSP synthase. Overall, results confirmed reduced glyphosate uptake and translocation as being the mechanism involved in glyphosate resistance in the RG biotype. RG biotype responses to the alternative treatments tested in situ indicated that herbicide applications at the later growth stage tended to be less effective in terms of immediate effects on population size than earlier applications, and that only in some cases, the removal of at least 85% of the RG biotype was achieved. However, with few

  4. Evolutionary history of tall fescue morphotypes inferred from molecular phylogenetics of the Lolium-Festuca species complex

    PubMed Central

    2010-01-01

    Background The agriculturally important pasture grass tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum (Schreb.) Darbysh.) is an outbreeding allohexaploid, that may be more accurately described as a species complex consisting of three major (Continental, Mediterranean and rhizomatous) morphotypes. Observation of hybrid infertility in some crossing combinations between morphotypes suggests the possibility of independent origins from different diploid progenitors. This study aims to clarify the evolutionary relationships between each tall fescue morphotype through phylogenetic analysis using two low-copy nuclear genes (encoding plastid acetyl-CoA carboxylase [Acc1] and centroradialis [CEN]), the nuclear ribosomal DNA internal transcribed spacer (rDNA ITS) and the chloroplast DNA (cpDNA) genome-located matK gene. Other taxa within the closely related Lolium-Festuca species complex were also included in the study, to increase understanding of evolutionary processes in a taxonomic group characterised by multiple inter-specific hybridisation events. Results Putative homoeologous sequences from both nuclear genes were obtained from each polyploid species and compared to counterparts from 15 diploid taxa. Phylogenetic reconstruction confirmed F. pratensis and F. arundinacea var. glaucescens as probable progenitors to Continental tall fescue, and these species are also likely to be ancestral to the rhizomatous morphotype. However, these two morphotypes are sufficiently distinct to be located in separate clades based on the ITS-derived data set. All four of the generated data sets suggest independent evolution of the Mediterranean and Continental morphotypes, with minimal affinity between cognate sequence haplotypes. No obvious candidate progenitor species for Mediterranean tall fescues were identified, and only two putative sub-genome-specific haplotypes were identified for this morphotype. Conclusions This study describes the first phylogenetic analysis of

  5. Reduction of atherosclerosis in cholesterol-fed rabbits and decrease of expressions of intracellular adhesion molecule-1 and vascular endothelial growth factor in foam cells by a water-soluble fraction of Polygonum multiflorum.

    PubMed

    Yang, Peng-Yuan; Almofti, Mohamad Radwan; Lu, Ling; Kang, Hui; Zhang, Jing; Li, Tie-Jun; Rui, Yao-Cheng; Sun, Lian-Na; Chen, Wan-Sheng

    2005-11-01

    Polygonum multiflorum stilbeneglycoside (PMS) is a water-soluble fraction of Polygonum multiflorum Thunb., one of the most famous tonic traditional Chinese medicines, that has protective effects on the cardiovascular system. The purpose of the present study is to elucidate the effects of PMS on macrophage-derived foam cell functions and the reduction of severity of atherosclerosis in hypercholesterolemic New Zealand White (NZW) rabbits. NZW rabbits were fed for 12 weeks with a normal diet, a high cholesterol diet, or a high cholesterol diet associated with irrigation with different doses of PMS (25, 50, or 100 mg/kg). Treatment of NZW rabbits fed with high cholesterol diet with 100 mg/kg PMS attenuated the increase in plasma cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and plasma triglyceride. Treatment with 50 and 100 mg/kg PMS caused 43% and 60% decrease in atherosclerotic lesioned area ratio to total surface area, respectively. In U937 foam cells, PMS could decrease the high expression of intercellular adhesion molecule (ICAM)-1 protein and the vascular endothelial growth factor (VEGF) protein levels in the medium induced by oxidized lipoprotein when analyzed by flow cytometry. The results proved that PMS is a powerful agent against atherosclerosis and that PMS action could possibly be through the inhibition of the expression of ICAM-1 and VEGF in foam cells.

  6. Allelopathic Potential of Switchgrass ( Panicum virgatum L.) on Perennial Ryegrass ( Lolium perenne L.) and Alfalfa ( Medicago sativa L.)

    NASA Astrophysics Data System (ADS)

    Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

    2010-10-01

    This study investigated allelopathy and its chemical basis in nine switchgrass ( Panicum virgatum L.) accessions. Perennial ryegrass ( Lolium perenne L.) and alfalfa ( Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China’s Loess Plateau.

  7. Effects of amendments on copper, cadmium, and lead phytoextraction by Lolium perenne from multiple-metal contaminated solution.

    PubMed

    Gunawardana, B; Singhal, N; Johnson, A

    2011-03-01

    Chemical amendments can increase metal uptake by plant roots and translocation to shoots, however their effectiveness can be influenced by the presence of other amendments and metal ions in a multiple-metal environment. A range of amendments and combinations were tested to explore their effect on phytoextraction of Cu, Cd, and Pb by perennial ryegrass (Lolium perenne) from solutions containing one or more of these metals. The amendments studied included EDDS (an aminopolycarboxylic acid), histidine (an amino acid), citric acid (an organic acid), rhamnolipid (a biosurfactant) and sulfate (an inorganic ligand). For all amendment treatments, the presence of multiple metals in solution reduced shoot concentrations of Cd and Cu, while Pb levels in shoots were generally enhanced by the presence of Cu. Although slightly toxic to the plants, EDDS (1 mM) was the most effective individual amendment for enhancing shoot metal uptake and translocation from solution without significantly reducing biomass yield. The combination Rhm+Cit+EDDS resulted in the highest shoot metal concentrations of all the treatments but also caused severe phytotoxicity. Amendment combinations Rhm+His and Sulf+Cit were less toxic for plant growth while moderately enhancing metal mass accumulation in shoots and thus could be considered as alternative treatments for enhanced phytoextraction.

  8. Comparison of EDTA-enhanced phytoextraction and phytostabilisation strategies with Lolium perenne on a heavy metal contaminated soil.

    PubMed

    Lambrechts, Thomas; Gustot, Quentin; Couder, Eléonore; Houben, David; Iserentant, Anne; Lutts, Stanley

    2011-11-01

    Phytoremediation is a promising and cost-effective strategy to manage heavy metal polluted sites. In this experiment, we compared simultaneously phytoextraction and phytostabilisation techniques on a Cd and Zn contaminated soil, through monitoring of plant accumulation and leaching. Lolium perenne plants were cultivated for 2 months under controlled environmental conditions in a 27.6 dm(3)-pot experiment allowing the collect of leachates. The heavy metal phytoextraction was promoted by adding Na-EDTA (0.5 g kg(-1) of soil) in watering solution. Phytostabilisation was assessed by mixing soil with steel shots (1%) before L. perenne sowing. Presence of plants exacerbated heavy metal leaching, by improving soil hydraulic conductivity. Use of EDTA for phytoextraction led to higher concentration of heavy metal in shoots. However, this higher heavy metal extraction was insufficient to satisfactory reduce the heavy metal content in soil, and led to important heavy metal leaching induced by EDTA. On the other hand, addition of steel shots efficiently decreased both Cd and Zn mobility, according to 0.01 M CaCl(2) extraction, and leaching. However, improvement of growth conditions by steel shots led to higher heavy metal mass in shoot tissues. Therefore, soil heavy metal mobility and plant metal uptake are not systematically positively correlated.

  9. Physiological effects of magnetite (Fe3O4) nanoparticles on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta) plants.

    PubMed

    Wang, Huanhua; Kou, Xiaoming; Pei, Zhiguo; Xiao, John Q; Shan, Xiaoquan; Xing, Baoshan

    2011-03-01

    To date, knowledge gaps and associated uncertainties remain unaddressed on the effects of nanoparticles (NPs) on plants. This study was focused on revealing some of the physiological effects of magnetite (Fe(3)O(4)) NPs on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta cv. white cushaw) plants under hydroponic conditions. This study for the first time reports that Fe(3)O(4) NPs often induced more oxidative stress than Fe(3)O(4) bulk particles in the ryegrass and pumpkin roots and shoots as indicated by significantly increased: (i) superoxide dismutase and catalase enzyme activities, and (ii) lipid peroxidation. However, tested Fe(3)O(4) NPs appear unable to be translocated in the ryegrass and pumpkin plants. This was supported by the following data: (i) No magnetization was detected in the shoots of either plant treated with 30, 100 and 500 mg l(-1) Fe(3)O(4) NPs; (ii) Fe K-edge X-ray absorption spectroscopic study confirmed that the coordination environment of Fe in these plant shoots was similar to that of Fe-citrate complexes, but not to that of Fe(3)O(4) NPs; and (iii) total Fe content in the ryegrass and pumpkin shoots treated with Fe(3)O(4) NPs was not significantly increased compared to that in the control shoots.

  10. Competition for /sup 15/N labelled ammonium between Trifolium subterraneum L. and Lolium multiflorium L. when grown in a mixture

    SciTech Connect

    Munoz Espinoza, A.E.

    1985-01-01

    Grasses and legumes are often grown in association in pastures because total herbage yield and forage quality is often higher than a monoculture grass sward. The competitive ability of the forage species for mineral N influences the stability of the mixed pasture. Mt. Barker subterranean clover (Trifolium subterraneum L.) Gulf ryegrass (Lolium multiflorium L.) were grown in pure stands and in mixtures in 3.8 I pots filled with exploded vermiculite to quantity the competition for applied mineral nitrogen (N). The isotope dilution technique using /sup 15/NH/sub 4/ was used. Also, the effect of increasing rates of fertilizer N on nodulation and fixation by subterranean clover and the rate of N uptake of subterranean clover and ryegrass was measured. The acetylene-ethylene technique and nodulation rating were used to examine the effect of N fertilization on fixation and nodulation. The uptake of N fertilizer by subterranean clover and ryegrass in both pure stands and the mixtures increased as the rate of fertilizer N applied increased. When grown in a pure stand, subterranean clover recovered a comparable amount of fertilizer N, but when grown in mixture with ryegrass, subterranean clover recovered from 44 to 364 mg of N. Ryegrass recovered 2 times the amount of labelled N in 6 hours than subterranean clover. The rate of N uptake was not due to differences in root fresh weight or dry weight. Ryegrass appeared to be a better competitor for NH/sub 4/ than subterranean clover because of the greater rate of uptake.

  11. Arsenic extractability and uptake by velvetgrass Holcus lanatus and ryegrass Lolium perenne in variously treated soils polluted by tailing spills.

    PubMed

    Karczewska, Anna; Lewińska, Karolina; Gałka, Bernard

    2013-11-15

    Phytostabilization should be considered as an appropriate phytoremediation technique to restore the area affected by tailing spills in Zloty Stok, where arsenic ores were mined and processed for several centuries. The study aimed to compare the suitability of velvetgrass (Holcus lanatus L.) and ryegrass (Lolium perenne L.) for development of plant cover in that area. Various treatments commonly applied to support phytostabilization were examined. A pot experiment was carried out to assess the effects of soil amendment with phosphate (P), sewage sludge (SS) and iron salts (Fe) on arsenic extractability and its uptake by grass. Four kinds of soil material, containing 356-5350 mg kg(-1) As, were examined. Velvetgrass proved to be more resistant than ryegrass to the toxicity of soil arsenic. Ammonium sulphate extractability of As in soils correlated well with As concentrations in the biomass of both grass species. In three of four tested soils, application of Fe failed to decrease As extractability and to reduce its concentrations in the aboveground parts of grasses. Application of P and SS resulted in increased As solubility in soils, but their effects on plant biomass and As uptake were ambiguous. SS had a strong beneficial influence on the growth of velvetgrass, while such an effect was not observed for ryegrass.

  12. Green and blue light photoreceptors are involved in maintenance of dormancy in imbibed annual ryegrass (Lolium rigidum) seeds.

    PubMed

    Goggin, Danica E; Steadman, Kathryn J; Powles, Stephen B

    2008-01-01

    Light plays an important role in two separate processes within the seeds of Lolium rigidum (annual ryegrass). Dormant seeds of L. rigidum remain dormant when imbibed in the light, but once seeds have lost dormancy through dark-stratification, light stimulates their germination. This study characterizes the light qualities and quantities which are effective in maintenance of dormancy. Dormant seeds were stratified under narrow- and broad-waveband light to identify the potential photoreceptors involved in dormancy maintenance, and to determine whether dark-induced dormancy loss is reversible by light. Blue and green light both mediated dormancy maintenance in a far-red-independent manner. Red light resulted in dormancy maintenance only when far-red wavelengths were excluded, suggesting a redundant function of phytochrome. At low fluence rates, white light was more effective than monochromatic light, suggesting the action of multiple photoreceptors in dormancy maintenance. By contrast, nondormant seeds did not germinate unless provided with red light. These results indicate that seed dormancy maintenance is potentially mediated through the actions of blue and green light photoreceptors. Seed dormancy could thus be added to the growing list of plant responses that may be mediated by green light in a cryptochrome-independent manner.

  13. In Silico Identification of Candidate Genes for Fertility Restoration in Cytoplasmic Male Sterile Perennial Ryegrass (Lolium perenne L.)

    PubMed Central

    Sykes, Timothy; Yates, Steven; Nagy, Istvan; Asp, Torben; Small, Ian

    2017-01-01

    Perennial ryegrass (Lolium perenne L.) is widely used for forage production in both permanent and temporary grassland systems. To increase yields in perennial ryegrass, recent breeding efforts have been focused on strategies to more efficiently exploit heterosis by hybrid breeding. Cytoplasmic male sterility (CMS) is a widely applied mechanism to control pollination for commercial hybrid seed production and although CMS systems have been identified in perennial ryegrass, they are yet to be fully characterized. Here, we present a bioinformatics pipeline for efficient identification of candidate restorer of fertility (Rf) genes for CMS. From a high-quality draft of the perennial ryegrass genome, 373 pentatricopeptide repeat (PPR) genes were identified and classified, further identifying 25 restorer of fertility-like PPR (RFL) genes through a combination of DNA sequence clustering and comparison to known Rf genes. This extensive gene family was targeted as the majority of Rf genes in higher plants are RFL genes. These RFL genes were further investigated by phylogenetic analyses, identifying three groups of perennial ryegrass RFLs. These three groups likely represent genomic regions of active RFL generation and identify the probable location of perennial ryegrass PPR-Rf genes. This pipeline allows for the identification of candidate PPR-Rf genes from genomic sequence data and can be used in any plant species. Functional markers for PPR-Rf genes will facilitate map-based cloning of Rf genes and enable the use of CMS as an efficient tool to control pollination for hybrid crop production. PMID:26951780

  14. Effects of GA3 on Plant Physiological Properties, Extraction, Subcellular Distribution and Chemical Forms of Pb in Lolium perenne.

    PubMed

    He, Shanying; He, Zhenli; Wu, Qiuling; Wang, Lei; Zhang, Xi

    2015-01-01

    The effects of growth-promoting hormone gibberellic acid 3 (GA3) on physiology, Pb phytoextraction, and metal detoxification mechanisms in Lolium perenne were studied. Results showed that addition of GA3 alone at lower doses (1 or 10 μM) facilitated antioxidant defense of L. perenne under Pb stress, decreased the toxicity of Pb in plant shoot by increasing the proportion of Pb in cell wall, hence significantly enhanced photosynthesis and plant growth, as well as Pb uptake and accumulation in L. perenne (P < 0.05). However, these indicators showed the opposite changes when treated with GA3 at a higher dose (100 μM). Of the total Pb in plant shoot, 36-51% was associated with cell wall, and 31-40% was soluble fraction, while 41.4-49.7% was NaCl extractable, 24.6-35.4% HAc extractable followed by other fractions. These findings suggest that Pb fixation by pectates and proteins in cell wall and sequestration in vacuole are responsible for Pb detoxification in plant, and the GA3 at 1 μM appears to be optimal for enhancing Pb phytoextraction by L. perenne from Pb polluted soils.

  15. Metabolic profiling of Lolium perenne shows functional integration of metabolic responses to diverse subtoxic conditions of chemical stress.

    PubMed

    Serra, Anne-Antonella; Couée, Ivan; Renault, David; Gouesbet, Gwenola; Sulmon, Cécile

    2015-04-01

    Plant communities are confronted with a great variety of environmental chemical stresses. Characterization of chemical stress in higher plants has often been focused on single or closely related stressors under acute exposure, or restricted to a selective number of molecular targets. In order to understand plant functioning under chemical stress conditions close to environmental pollution conditions, the C3 grass Lolium perenne was subjected to a panel of different chemical stressors (pesticide, pesticide degradation compound, polycyclic aromatic hydrocarbon, and heavy metal) under conditions of seed-level or root-level subtoxic exposure. Physiological and metabolic profiling analysis on roots and shoots revealed that all of these subtoxic chemical stresses resulted in discrete physiological perturbations and complex metabolic shifts. These metabolic shifts involved stressor-specific effects, indicating multilevel mechanisms of action, such as the effects of glyphosate and its degradation product aminomethylphosphonic acid on quinate levels. They also involved major generic effects that linked all of the subtoxic chemical stresses with major modifications of nitrogen metabolism, especially affecting asparagine, and of photorespiration, especially affecting alanine and glycerate. Stress-related physiological effects and metabolic adjustments were shown to be integrated through a complex network of metabolic correlations converging on Asn, Leu, Ser, and glucose-6-phosphate, which could potentially be modulated by differential dynamics and interconversion of soluble sugars (sucrose, trehalose, fructose, and glucose). Underlying metabolic, regulatory, and signalling mechanisms linking these subtoxic chemical stresses with a generic impact on nitrogen metabolism and photorespiration are discussed in relation to carbohydrate and low-energy sensing.

  16. Allelopathic potential of switchgrass (Panicum virgatum L.) on perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.).

    PubMed

    Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

    2010-10-01

    This study investigated allelopathy and its chemical basis in nine switchgrass (Panicum virgatum L.) accessions. Perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China's Loess Plateau.

  17. The role of sulfur- and phosphorus-mobilizing bacteria in biochar-induced growth promotion of Lolium perenne.

    PubMed

    Fox, Aaron; Kwapinski, Witold; Griffiths, Bryan S; Schmalenberger, Achim

    2014-10-01

    Plants rely on microorganisms to mobilize organically and inorganically bound sulfur (S) and phosphorus (P) in which the plant can then readily utilize. The aim of this study was to investigate the role of S- and P-mobilizing bacteria in plant growth promotion in biochar-amended soil, which has been rarely investigated so far. Pot experiments of Lolium perenne were established on S and P limited soil with 1% or 2% biochar (Miscanthus × giganteus) or without biochar (control) for a period of 126 days. Both biochar amendments resulted in significant plant growth promotion. Rhizobacteria capable of growing with (1) S from aromatic sulfonates, (2) P from phosphate esters, (3) P from phosphonates, and (4) P from tri-calcium phosphates as sole source of S or P, respectively, were significantly more abundant in the biochar treatments. 16S rRNA gene-based rhizobacteria community analysis revealed a significant biochar treatment effect. Abundance of nematodes feeding on bacteria was also significantly increased in the biochar treatments. Diversity analysis of rhizospheric asfA and phnJ genes revealed broad sequence diversities in bacterial sulfonate and phosphonate-mineralizing capabilities. These findings suggest that biochar amendment enhances microbially mediated nutrient mobilization of S and P resulting in improved plant growth.

  18. Toxicity of eight polycyclic aromatic compounds to red clover (Trifolium pratense), ryegrass (Lolium perenne), and mustard (Sinapsis alba).

    PubMed

    Sverdrup, Line E; Krogh, Paul Henning; Nielsen, Torben; Kjaer, Christian; Stenersen, Jørgen

    2003-12-01

    The effect of eight polycyclic aromatic compounds (PACs) on the seed emergence and early life-stage growth of three terrestrial plants (Sinapsis alba, Trifolium pratense and Lolium perenne) were studied in a greenhouse, using a Danish agricultural soil with an organic carbon content of 1.6%. After three weeks of exposure, seed emergence and seedling weight (fresh weight and dry weight) were determined. Exposure concentrations were verified with chemical analysis. The substances tested were four polycyclic aromatic hydrocarbons (fluoranthene, pyrene, phenanthrene and fluorene), the N-, S-, and O-substituted analogues of fluorene (carbazole, dibenzothiophene and dibenzofuran, respectively), and the quinoline representative acridine. Seedling growth was a far more sensitive endpoint than seed emergence for all substances. Concentrations estimated to give a 20% reduction of seedling fresh weight (EC20-values) ranged from 36 to 290 mgkg(-1) for carbazole, 43 to 93 mgkg(-1) for dibenzofuran, 37 to 110 mgkg(-1) for dibenzothiophene, 140 to 650 mgkg(-1) for fluoranthene, 55 to 380 mgkg(-1) for fluorene, 37 to 300 mgkg(-1) for phenanthrene, and 49 to 1300 mgkg(-1) for pyrene. For acridine, no toxicity was observed within the concentration range tested (1-1000 mgkg(-1)). As illustrated by the EC20-values, there was a rather large difference in sensitivity between the species, and T. pratense was the most sensitive of the species tested.

  19. Anti-proliferative effect of an extract of the root of Polygonum multiflorum Thunb. on MCF-7 human breast cancer cells and the possible mechanisms.

    PubMed

    Chen, Hong-Sheng; Liu, Yan; Lin, Luo-Qiang; Zhao, Jin-Lu; Zhang, Chun-Peng; Jin, Jun-Chao; Wang, Lei; Bai, Ming-Han; Wang, Yi-Chong; Liu, Ming; Shen, Bao-Zhong

    2011-01-01

    The root of Polygonum multiflorum Thunb. (PM) is utilized to treat many diseases associated with aging. Research also indicates that PM inhibits the proliferation of certain types of cancer cells. The aim of the present study was to evaluate the inhibitory effect of PM extract (PME) on the proliferation of MCF-7 cells and to investigate the underlying mechanisms. Inhibition of the proliferation of MCF-7 cells was determined by the MTT assay. Cell cycle distribution and apoptotic rates were evaluated by flow cytometry, and cell cycle and apoptosis-related protein expression was assessed by Western blotting. Apoptotic characteristics of MCF-7 cells were detected by transmission electron microscopy. The present study showed that PME at doses of 100, 150, 200 and 250 µg/ml significantly inhibited proliferation of MCF-7 cells in a time- and dose-dependent manner. Flow cytometry showed that the cell apoptotic rates were 9.1 ± 1.67 and 17.7 ± 2.93% after treatment with 100 and 200 µg/ml PME for 48 h, respectively. The proportions of cells in the G2/M phase were 37.9 ± 1.47 and 42.0 ± 1.71% after treatment with 100 and 200 µg/ml PME for 24 h, respectively. Western blot analysis showed that PME down-regulated the protein expression of Cdc25B and Cdc25C phosphatases accompanied by an increase in phospho-Cdk1, and PME promoted cytochrome c release from mitochondria into the cytosol to activate caspase-9. The present study demonstrated that PME inhibited MCF-7 cell proliferation by inducing cell cycle arrest in the G2/M phase and promoting cell apoptosis. The effects of PME on MCF-7 cells were associated with the modulation of the expression levels of proteins involved in the cell cycle and apoptosis. These data suggest that PME has promise as a treatment against breast cancer by inhibiting the proliferation of cancer cells.

  20. Investigating the Mechanism of Glyphosate Resistance in Rigid Ryegrass (Lolium rigidum)

    USDA-ARS?s Scientific Manuscript database

    Glyphosate is a broad-spectrum herbicide that has been used extensively for more than 20 yr. The first glyphosate-resistant weed biotype appeared in 1996; it involved a rigid ryegrass population from Australia that exhibited an LD50 value approximately 10-fold higher than that of sensitive biotypes....

  1. Aquaculture solids management using a combination of sand/gravel or unwoven fabric bed with Lolium perenne Lam as a plant biofilter.

    PubMed

    Nduwimana, André; Yang, Xiang-Long; Wang, Li-Ren

    2007-12-01

    This work is an evaluation of the efficiency of a sand-gravel or unwoven fabric bed system and Lolium perenne Lam as plant biofilter in the reduction of solids and nutrients removal from aquaculture discharge water. The first step consisted of the collection of wastewater in the tank and the distribution at three different hydraulic loading regimes (0.5, 1, 1.5 L/hour) to the different experimental systems. The second step was to evaluate the performance of the different systems. The first system consisted of a bucket filled with a substrate of sand/gravel (20 cm in depth), on the bottom of which was a 80 mesh/inch2 of nylon (S1); the second was similar, but was planted with Lolium perenne lam (S2); the third was planted with a grass plate consisting of 7 layers of unwoven fabric planted with L perenne (S3). The second system showed the best performance in reducing solids as well as in nutrients (TN, TP, and COD) reduction. The removal rates for TS, TN, and TP were negatively correlated with the loading regimes, with 0.5 L/hour being the most efficient and thus taken as the reference. Solids management using a sand/gravel substrate as bed culture and Lolium perenne L. as plant biofilter has proved to be an efficient technique for solids reduction with low operating cost. This grass plays an important role in wastewater eco-treatment by absorbing dissolved pollutants (TAN) as nutrients for its growth.

  2. Effect of combined pollution of chromium and benzo(a)pyrene on seed growth of Lolium perenne.

    PubMed

    Chigbo, Chibuike; Batty, Lesley

    2013-01-01

    The single and joint effects of chromium (Cr) and benzo (a) pyrene (B (a) P) on the seed germination and the elongation of root and shoot of Lolium perenne were investigated. Seed germination represents the first important step to effective phytoremediation. Young seedlings may be susceptible to PAH and heavy metal contaminants. The results showed that in solution, increasing concentration of Cr could inhibit the germination rate as well as root and shoot elongation of L. perenne. Also, the increasing concentration of B (a) P (1-4 mg L(-1)) could accelerate the germination rate. The joint toxicity of Cr and B (a) P showed that increasing concentration of Cr and B (a) P had significant antagonistic effect on the germination rate of L. perenne. In the single factor experiments and joint effect tests of Cr and B (a) P on the seedling growth, the root and shoot elongation were inhibited significantly (p<0.05) for higher concentration of Cr whereas increasing concentration of B (a) P accelerated the shoot elongation. There were significant relationships between the concentration of pollutants and root and shoot elongation (p<0.05). Higher concentration of B (a) P with low concentration of Cr had significant antagonistic effect on shoot and root elongation of L. perenne in solution tests. Also, low concentration of B (a) P with increasing concentration of Cr had a significant synergistic effect on shoot elongation. The toxicity effects of Cr and B (a) P to seed germination, root and shoot elongation are-root elongation>shoot elongation>germination rate.

  3. Olivine weathering in soil, and its effects on growth and nutrient uptake in Ryegrass (Lolium perenne L.): a pot experiment.

    PubMed

    ten Berge, Hein F M; van der Meer, Hugo G; Steenhuizen, Johan W; Goedhart, Paul W; Knops, Pol; Verhagen, Jan

    2012-01-01

    Mineral carbonation of basic silicate minerals regulates atmospheric CO(2) on geological time scales by locking up carbon. Mining and spreading onto the earth's surface of fast-weathering silicates, such as olivine, has been proposed to speed up this natural CO(2) sequestration ('enhanced weathering'). While agriculture may offer an existing infrastructure, weathering rate and impacts on soil and plant are largely unknown. Our objectives were to assess weathering of olivine in soil, and its effects on plant growth and nutrient uptake. In a pot experiment with perennial ryegrass (Lolium perenne L.), weathering during 32 weeks was inferred from bioavailability of magnesium (Mg) in soil and plant. Olivine doses were equivalent to 1630 (OLIV1), 8150, 40700 and 204000 (OLIV4) kg ha(-1). Alternatively, the soluble Mg salt kieserite was applied for reference. Olivine increased plant growth (+15.6%) and plant K concentration (+16.5%) in OLIV4. At all doses, olivine increased bioavailability of Mg and Ni in soil, as well as uptake of Mg, Si and Ni in plants. Olivine suppressed Ca uptake. Weathering estimated from a Mg balance was equivalent to 240 kg ha(-1) (14.8% of dose, OLIV1) to 2240 kg ha(-1) (1.1%, OLIV4). This corresponds to gross CO(2) sequestration of 290 to 2690 kg ha(-1) (29 10(3) to 269 10(3) kg km(-2).) Alternatively, weathering estimated from similarity with kieserite treatments ranged from 13% to 58% for OLIV1. The Olsen model for olivine carbonation predicted 4.0% to 9.0% weathering for our case, independent of olivine dose. Our % values observed at high doses were smaller than this, suggesting negative feedbacks in soil. Yet, weathering appears fast enough to support the 'enhanced weathering' concept. In agriculture, olivine doses must remain within limits to avoid imbalances in plant nutrition, notably at low Ca availability; and to avoid Ni accumulation in soil and crop.

  4. Exogenous Application of Citric Acid Ameliorates the Adverse Effect of Heat Stress in Tall Fescue (Lolium arundinaceum)

    PubMed Central

    Hu, Longxing; Zhang, Zhifei; Xiang, Zuoxiang; Yang, Zhijian

    2016-01-01

    Citric acid may be involved in plant response to high temperature. The objective of this study was to investigate whether exogenous citric acid could improve heat tolerance in a cool-season turfgrass species, tall fescue (Lolium arundinaceum), and to determine the physiological mechanisms of citric acid effects on heat stress tolerance. The grasses were subjected to four citric acid levels (0, 0.2, 2, and 20 mM) and two temperature levels (25/20 and 35/30 ± 0.5°C, day/night) treatments in growth chambers. Heat stress increased an electrolyte leakage (EL) and malonaldehyde (MDA) content, while reduced plant growth, chlorophyll (Chl) content, photochemical efficiency (Fv/Fm), root activity and antioxidant enzyme activities (superoxide dismutase, SOD; catalase, CAT; peroxidase, POD). External citric acid alleviated the detrimental effects of heat stress on tall fescue, which was evidenced by decreased EL and MDA content, and improved plant growth under stress conditions. Additionally, the reduction in Chl content, Fv/Fm, SOD, POD, CAT and root activity were ameliorated in citric acid treated plants under heat stressed conditions. High temperature induced the expression of heat shock protein (HSP) genes, which exhibited greater expression levels after citric acid treatment under heat stress. These results suggest that exogenous citric acid application may alleviate growth and physiological damage caused by high temperature. In addition, the exogenously applied citric acid might be responsible for maintaining membrane stability, root activity, and activation of antioxidant response and HSP genes which could contribute to the protective roles of citric acid in tall fescue responses to heat stress. PMID:26925085

  5. Metabolic changes and associated cytokinin signals in response to nitrate assimilation in roots and shoots of Lolium perenne.

    PubMed

    Roche, Jessica; Love, Jonathan; Guo, Qianqian; Song, Jiancheng; Cao, Mingshu; Fraser, Karl; Huege, Jan; Jones, Chris; Novák, Ondřej; Turnbull, Matthew H; Jameson, Paula E

    2016-04-01

    The efficiency of inorganic nitrogen (N) assimilation is a critical component of fertilizer use by plants and of forage production in Lolium perenne, an important pasture species worldwide. We present a spatiotemporal description of nitrate use efficiency in terms of metabolic responses and carbohydrate remobilization, together with components of cytokinin signal transduction following nitrate addition to N-impoverished plants. Perennial ryegrass (L. perenne cv. Grasslands Nui) plants were grown for 10 weeks in unfertilized soil and then treated with nitrate (5 mM) hydroponically. Metabolomic analysis by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry revealed a dynamic interaction between N and carbon metabolism over a week-long time course represented by the relative abundance of amino acids, tricarboxylic acid intermediates and stored water-soluble carbohydrates (WSCs). The initial response to N addition was characterized by a rapid remobilization of carbon stores from the low-molecular weight WSC, along with an increase in N content and assimilation into free amino acids. Subsequently, the shoot became the main source of carbon through remobilization of a large pool of high-molecular weight WSC. Associated quantification of cytokinin levels and expression profiling of putative cytokinin response regulator genes by quantitative reverse transcription polymerase chain reaction support a role for cytokinin in the mediation of the response to N addition in perennial ryegrass. The presence of high levels of cis-zeatin-type cytokinins is discussed in the context of hormonal homeostasis under the stress of steady-state N deficiency.

  6. Evaluation of a cost effective technique for treating aquaculture water discharge using Lolium perenne Lam as a biofilter.

    PubMed

    Nduwimana, André; Yang, Xiang-Long; Wang, Li-Ren

    2007-01-01

    Wastewater stabilization ponds generate low cost by-products that are useful for agriculture. The utilization of these by-products for soil amendment and as a source of nutrients for plants requires a high level of sanitation and stabilization of the organic matter, to maintain acceptable levels of soil, water and air quality. In this study, two aquaculture wastewater treatment systems; recirculating system and a floating plant bed system were designed to improve the quality of irrigation water in local communities with low income. In both systems the grass species Lolium perenne Lam was used as a plant biofilter while vegetable specie Amaranthus viridis was used to evaluate the performance of the system and the suitability of the phyto-treated water for irrigation. It was found that the harmful material removal rate for recirculating system was 88.9% for TAN (total ammonia nitrogen), 90% for NO2(-)-N, 64.8% for NO3(-)-N while for floating plant bed system 82.7% for TAN, 82% for NO2(-)-N and 60.5% for NO3(-)-N. Comparative analysis of the efficiency of waste element removal between the two systems revealed that both systems performed well, however, plant growth was not robust for floating plant bed system while recirculating system is energy consuming. Although both systems did not attain sufficient levels of TN (total nitrogen) and TP (total phosphorus) load reduction, the treatment with L. perenne remarkably improved the irrigation water quality. A. viridis plants irrigated with the phyto-treated discharge water had lesser concentrations of heavy metals in their tissues compared to those irrigated with untreated discharge. The control plants irrigated with untreated discharge were also found to be highly lignified with few stems and small leaves.

  7. Exogenous Classic Phytohormones Have Limited Regulatory Effects on Fructan and Primary Carbohydrate Metabolism in Perennial Ryegrass (Lolium perenne L.).

    PubMed

    Gasperl, Anna; Morvan-Bertrand, Annette; Prud'homme, Marie-Pascale; van der Graaff, Eric; Roitsch, Thomas

    2015-01-01

    Fructans are polymers of fructose and one of the main constituents of water-soluble carbohydrates in forage grasses and cereal crops of temperate climates. Fructans are involved in cold and drought resistance, regrowth following defoliation and early spring growth, seed filling, have beneficial effects on human health and are used for industrial processes. Perennial ryegrass (Lolium perenne L.) serves as model species to study fructan metabolism. Fructan metabolism is under the control of both synthesis by fructosyltransferases (FTs) and breakdown through fructan exohydrolases (FEHs). The accumulation of fructans can be triggered by high sucrose levels and abiotic stress conditions such as drought and cold stress. However, detailed studies on the mechanisms involved in the regulation of fructan metabolism are scarce. Since different phytohormones, especially abscisic acid (ABA), are known to play an important role in abiotic stress responses, the possible short term regulation of the enzymes involved in fructan metabolism by the five classical phytohormones was investigated. Therefore, the activities of enzymes involved in fructan synthesis and breakdown, the expression levels for the corresponding genes and levels for water-soluble carbohydrates were determined following pulse treatments with ABA, auxin (AUX), ethylene (ET), gibberellic acid (GA), or kinetin (KIN). The most pronounced fast effects were a transient increase of FT activities by AUX, KIN, ABA, and ET, while minor effects were evident for 1-FEH activity with an increased activity in response to KIN and a decrease by GA. Fructan and sucrose levels were not affected. This observed discrepancy demonstrates the importance of determining enzyme activities to obtain insight into the physiological traits and ultimately the plant phenotype. The comparative analyses of activities for seven key enzymes of primary carbohydrate metabolism revealed no co-regulation between enzymes of the fructan and sucrose pool.

  8. The photosynthetic acclimation of Lolium perenne growing in a free-air CO2 enrichment (FACE) system

    SciTech Connect

    Bryant, Jonathan B.

    1994-11-01

    Stands of Ryegrass (Lolium perenne L. cv. Bastion) were grown in the field at ambient or elevated (600μmol/mol) CO2 concentration, high (560Kg/ha) or low (140Kg/ha) nitrogen addition and with a frequent (every 4 weeks) or infrequent (every 8 weeks) cutting regime. Plants were in the second year of a 3 year experiment. Exposure to elevated CO2 was carried out with a Free-Air CO2 Enrichment (FACE) system which provides the most "realistic" system of CO2 fumigation currently available. Elevated CO2 increased diurnal CO2 assimilation by between 34 and 88% whilst reducing rates of stomatal conductance by between 1 and 42%. However, analysis of the A vs. Ci response showed considerable acclimation of the photosynthetic apparatus in response to elevated CO2 - Vcmax as an in vivo measure of RubisCO activity, decreased by between 29 and 35% in high CO2, whilst Jmax, as a measure of the RubP regeneration capacity, showed no significant change. Two out of three additional perennial grassland species studied showed similar acclamatory behavior to Ryegrass. Diurnal assimilation rate, Jmax and, in most cases, Vcmax, increased significantly directly after cutting of Ryegrass stands, but nitrogen treatment had little effect on any of these parameters. Neither stomatal density, stomatal index nor stomatal pore length of Ryegrass were significantly altered by growth in elevated CO2. The results are discussed in terms of the limitation imposed on maximizing photosynthetic and growth responses of Ryegrass at elevated CO2, by the ability of perennial species to increase long-term sink capacity under these conditions.

  9. Exogenous Classic Phytohormones Have Limited Regulatory Effects on Fructan and Primary Carbohydrate Metabolism in Perennial Ryegrass (Lolium perenne L.)

    PubMed Central

    Gasperl, Anna; Morvan-Bertrand, Annette; Prud'homme, Marie-Pascale; van der Graaff, Eric; Roitsch, Thomas

    2016-01-01

    Fructans are polymers of fructose and one of the main constituents of water-soluble carbohydrates in forage grasses and cereal crops of temperate climates. Fructans are involved in cold and drought resistance, regrowth following defoliation and early spring growth, seed filling, have beneficial effects on human health and are used for industrial processes. Perennial ryegrass (Lolium perenne L.) serves as model species to study fructan metabolism. Fructan metabolism is under the control of both synthesis by fructosyltransferases (FTs) and breakdown through fructan exohydrolases (FEHs). The accumulation of fructans can be triggered by high sucrose levels and abiotic stress conditions such as drought and cold stress. However, detailed studies on the mechanisms involved in the regulation of fructan metabolism are scarce. Since different phytohormones, especially abscisic acid (ABA), are known to play an important role in abiotic stress responses, the possible short term regulation of the enzymes involved in fructan metabolism by the five classical phytohormones was investigated. Therefore, the activities of enzymes involved in fructan synthesis and breakdown, the expression levels for the corresponding genes and levels for water-soluble carbohydrates were determined following pulse treatments with ABA, auxin (AUX), ethylene (ET), gibberellic acid (GA), or kinetin (KIN). The most pronounced fast effects were a transient increase of FT activities by AUX, KIN, ABA, and ET, while minor effects were evident for 1-FEH activity with an increased activity in response to KIN and a decrease by GA. Fructan and sucrose levels were not affected. This observed discrepancy demonstrates the importance of determining enzyme activities to obtain insight into the physiological traits and ultimately the plant phenotype. The comparative analyses of activities for seven key enzymes of primary carbohydrate metabolism revealed no co-regulation between enzymes of the fructan and sucrose pool

  10. Synergetic effects of DA-6/GA₃ with EDTA on plant growth, extraction and detoxification of Cd by Lolium perenne.

    PubMed

    He, Shanying; Wu, Qiuling; He, Zhenli

    2014-12-01

    Research is needed to improve efficiency of phytoextraction of heavy metals from contaminated soils. A pot experiment was carried out to study the effects of plant growth regulators (PGRs) (diethyl aminoethyl hexanoate (C18H33NO8, DA-6) and gibberellic acid 3 (C19H22O6, GA3)) and/or EDTA on Cd extraction, subcellular distribution and chemical forms in Lolium perenne. The addition of EDTA or PGRs significantly enhanced Cd extraction efficiency (P<0.05), with the decreasing order of: 1 μM DA-6>10 μM DA-6>10 μM GA3>2.5 mmol kg(-1) EDTA>other treatments of PGR alone. PGRs+EDTA resulted in a further increase in Cd extraction efficiency, with EDTA+1 μM DA-6 being the most efficient. At the subcellular level, about 44-57% of Cd was soluble fraction, 18-44% in cell walls, and 12-25% in cellular organelles fraction. Chemical speciation analysis showed that 40-54% of Cd was NaCl extractable, 7-23% HAc extractable, followed by other fractions. EDTA increased the proportions of Cd in soluble and cellular organelles fraction, as well as the metal migration in shoot; therefore, the toxicity to plant increased and plant growth was inhibited. Conversely, PGRs fixed more Cd in cell walls and reduced Cd migration in shoot; thus, metal toxicity was reduced. In addition, PGRs promoted plant biomass growth significantly (P<0.05), with 1 μM DA-6 being the most effective. A combination of DA-6/GA3 with EDTA can alleviate the adverse effect of EDTA on plant growth, and the treatment of EDTA+1 μM DA-6 appears to be optimal for improving the remediation efficiency of L. perenne for Cd contaminated soil.

  11. Latitudinal variation in ambient UV-B radiation is an important determinant of Lolium perenne forage production, quality, and digestibility.

    PubMed

    Comont, David; Winters, Ana; Gomez, Leonardo D; McQueen-Mason, Simon J; Gwynn-Jones, Dylan

    2013-05-01

    Few studies to date have considered the responses of agriculturally important forage grasses to UV-B radiation. Yet grasses such as Lolium perenne have a wide current distribution, representing exposure to a significant variation in ambient UV-B. The current study investigated the responses of L. perenne (cv. AberDart) to a simulated latitudinal gradient of UV-B exposure, representing biologically effective UV-B doses at simulated 70, 60, 50, 40, and 30° N latitudes. Aspects of growth, soluble compounds, and digestibility were assessed, and results are discussed in relation to UV-B effects on forage properties and the implications for livestock and bio-ethanol production. Aboveground biomass production was reduced by approximately 12.67% with every 1 kJ m(-2) day(-1) increase in biologically weighted UV-B. As a result, plants grown in the highest UV-B treatment had a total biomass of just 13.7% of controls. Total flavonoids were increased by approximately 76% by all UV-B treatments, while hydroxycinnamic acids increased in proportion to the UV-B dose. Conversely, the digestibility of the aboveground biomass and concentrations of soluble fructans were reduced by UV-B exposure, although soluble sucrose, glucose, and fructose concentrations were unaffected. These results highlight the capacity for UV-B to directly affect forage productivity and chemistry, with negative consequences for digestibility and bioethanol production. Results emphasize the need for future development and distribution of L. perenne varieties to take UV-B irradiance into consideration.

  12. Metabolic profiling of Lolium perenne shows functional integration of metabolic responses to diverse subtoxic conditions of chemical stress

    PubMed Central

    Serra, Anne-Antonella; Couée, Ivan; Renault, David; Gouesbet, Gwenola; Sulmon, Cécile

    2015-01-01

    Plant communities are confronted with a great variety of environmental chemical stresses. Characterization of chemical stress in higher plants has often been focused on single or closely related stressors under acute exposure, or restricted to a selective number of molecular targets. In order to understand plant functioning under chemical stress conditions close to environmental pollution conditions, the C3 grass Lolium perenne was subjected to a panel of different chemical stressors (pesticide, pesticide degradation compound, polycyclic aromatic hydrocarbon, and heavy metal) under conditions of seed-level or root-level subtoxic exposure. Physiological and metabolic profiling analysis on roots and shoots revealed that all of these subtoxic chemical stresses resulted in discrete physiological perturbations and complex metabolic shifts. These metabolic shifts involved stressor-specific effects, indicating multilevel mechanisms of action, such as the effects of glyphosate and its degradation product aminomethylphosphonic acid on quinate levels. They also involved major generic effects that linked all of the subtoxic chemical stresses with major modifications of nitrogen metabolism, especially affecting asparagine, and of photorespiration, especially affecting alanine and glycerate. Stress-related physiological effects and metabolic adjustments were shown to be integrated through a complex network of metabolic correlations converging on Asn, Leu, Ser, and glucose-6-phosphate, which could potentially be modulated by differential dynamics and interconversion of soluble sugars (sucrose, trehalose, fructose, and glucose). Underlying metabolic, regulatory, and signalling mechanisms linking these subtoxic chemical stresses with a generic impact on nitrogen metabolism and photorespiration are discussed in relation to carbohydrate and low-energy sensing. PMID:25618145

  13. Latitudinal variation in ambient UV-B radiation is an important determinant of Lolium perenne forage production, quality, and digestibility

    PubMed Central

    Comont, David; Winters, Ana; Gomez, Leonardo D; McQueen-Mason, Simon J; Gwynn-Jones, Dylan

    2013-01-01

    Few studies to date have considered the responses of agriculturally important forage grasses to UV-B radiation. Yet grasses such as Lolium perenne have a wide current distribution, representing exposure to a significant variation in ambient UV-B. The current study investigated the responses of L. perenne (cv. AberDart) to a simulated latitudinal gradient of UV-B exposure, representing biologically effective UV-B doses at simulated 70, 60, 50, 40, and 30° N latitudes. Aspects of growth, soluble compounds, and digestibility were assessed, and results are discussed in relation to UV-B effects on forage properties and the implications for livestock and bio-ethanol production. Aboveground biomass production was reduced by approximately 12.67% with every 1 kJ m–2 day–1 increase in biologically weighted UV-B. As a result, plants grown in the highest UV-B treatment had a total biomass of just 13.7% of controls. Total flavonoids were increased by approximately 76% by all UV-B treatments, while hydroxycinnamic acids increased in proportion to the UV-B dose. Conversely, the digestibility of the aboveground biomass and concentrations of soluble fructans were reduced by UV-B exposure, although soluble sucrose, glucose, and fructose concentrations were unaffected. These results highlight the capacity for UV-B to directly affect forage productivity and chemistry, with negative consequences for digestibility and bioethanol production. Results emphasize the need for future development and distribution of L. perenne varieties to take UV-B irradiance into consideration. PMID:23580749

  14. Olivine Weathering in Soil, and Its Effects on Growth and Nutrient Uptake in Ryegrass (Lolium perenne L.): A Pot Experiment

    PubMed Central

    ten Berge, Hein F. M.; van der Meer, Hugo G.; Steenhuizen, Johan W.; Goedhart, Paul W.; Knops, Pol; Verhagen, Jan

    2012-01-01

    Mineral carbonation of basic silicate minerals regulates atmospheric CO2 on geological time scales by locking up carbon. Mining and spreading onto the earth's surface of fast-weathering silicates, such as olivine, has been proposed to speed up this natural CO2 sequestration (‘enhanced weathering’). While agriculture may offer an existing infrastructure, weathering rate and impacts on soil and plant are largely unknown. Our objectives were to assess weathering of olivine in soil, and its effects on plant growth and nutrient uptake. In a pot experiment with perennial ryegrass (Lolium perenne L.), weathering during 32 weeks was inferred from bioavailability of magnesium (Mg) in soil and plant. Olivine doses were equivalent to 1630 (OLIV1), 8150, 40700 and 204000 (OLIV4) kg ha−1. Alternatively, the soluble Mg salt kieserite was applied for reference. Olivine increased plant growth (+15.6%) and plant K concentration (+16.5%) in OLIV4. At all doses, olivine increased bioavailability of Mg and Ni in soil, as well as uptake of Mg, Si and Ni in plants. Olivine suppressed Ca uptake. Weathering estimated from a Mg balance was equivalent to 240 kg ha−1 (14.8% of dose, OLIV1) to 2240 kg ha−1 (1.1%, OLIV4). This corresponds to gross CO2 sequestration of 290 to 2690 kg ha−1 (29 103 to 269 103 kg km−2.) Alternatively, weathering estimated from similarity with kieserite treatments ranged from 13% to 58% for OLIV1. The Olsen model for olivine carbonation predicted 4.0% to 9.0% weathering for our case, independent of olivine dose. Our % values observed at high doses were smaller than this, suggesting negative feedbacks in soil. Yet, weathering appears fast enough to support the ‘enhanced weathering’ concept. In agriculture, olivine doses must remain within limits to avoid imbalances in plant nutrition, notably at low Ca availability; and to avoid Ni accumulation in soil and crop. PMID:22912685

  15. Orthology Guided Assembly in highly heterozygous crops: creating a reference transcriptome to uncover genetic diversity in Lolium perenne.

    PubMed

    Ruttink, Tom; Sterck, Lieven; Rohde, Antje; Bendixen, Christian; Rouzé, Pierre; Asp, Torben; Van de Peer, Yves; Roldan-Ruiz, Isabel

    2013-06-01

    Despite current advances in next-generation sequencing data analysis procedures, de novo assembly of a reference sequence required for SNP discovery and expression analysis is still a major challenge in genetically uncharacterized, highly heterozygous species. High levels of polymorphism inherent to outbreeding crop species hamper De Bruijn Graph-based de novo assembly algorithms, causing transcript fragmentation and the redundant assembly of allelic contigs. If multiple genotypes are sequenced to study genetic diversity, primary de novo assembly is best performed per genotype to limit the level of polymorphism and avoid transcript fragmentation. Here, we propose an Orthology Guided Assembly procedure that first uses sequence similarity (tBLASTn) to proteins of a model species to select allelic and fragmented contigs from all genotypes and then performs CAP3 clustering on a gene-by-gene basis. Thus, we simultaneously annotate putative orthologues for each protein of the model species, resolve allelic redundancy and fragmentation and create a de novo transcript sequence representing the consensus of all alleles present in the sequenced genotypes. We demonstrate the procedure using RNA-seq data from 14 genotypes of Lolium perenne to generate a reference transcriptome for gene discovery and translational research, to reveal the transcriptome-wide distribution and density of SNPs in an outbreeding crop and to illustrate the effect of polymorphisms on the assembly procedure. The results presented here illustrate that constructing a non-redundant reference sequence is essential for comparative genomics, orthology-based annotation and candidate gene selection but also for read mapping and subsequent polymorphism discovery and/or read count-based gene expression analysis. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  16. Clade classification of monolignol biosynthesis gene family members reveals target genes to decrease lignin in Lolium perenne.

    PubMed

    van Parijs, F R D; Ruttink, T; Boerjan, W; Haesaert, G; Byrne, S L; Asp, T; Roldán-Ruiz, I; Muylle, H

    2015-07-01

    In monocots, lignin content has a strong impact on the digestibility of the cell wall fraction. Engineering lignin biosynthesis requires a profound knowledge of the role of paralogues in the multigene families that constitute the monolignol biosynthesis pathway. We applied a bioinformatics approach for genome-wide identification of candidate genes in Lolium perenne that are likely to be involved in the biosynthesis of monolignols. More specifically, we performed functional subtyping of phylogenetic clades in four multigene families: 4CL, COMT, CAD and CCR. Essential residues were considered for functional clade delineation within these families. This classification was complemented with previously published experimental evidence on gene expression, gene function and enzymatic activity in closely related crops and model species. This allowed us to assign functions to novel identified L. perenne genes, and to assess functional redundancy among paralogues. We found that two 4CL paralogues, two COMT paralogues, three CCR paralogues and one CAD gene are prime targets for genetic studies to engineer developmentally regulated lignin in this species. Based on the delineation of sequence conservation between paralogues and a first analysis of allelic diversity, we discuss possibilities to further study the roles of these paralogues in lignin biosynthesis, including expression analysis, reverse genetics and forward genetics, such as association mapping. We propose criteria to prioritise paralogues within multigene families and certain SNPs within these genes for developing genotyping assays or increasing power in association mapping studies. Although L. perenne was the target of the analyses presented here, this functional subtyping of phylogenetic clades represents a valuable tool for studies investigating monolignol biosynthesis genes in other monocot species.

  17. Diversity of endophytic bacteria in Lolium perenne and their potential to degrade petroleum hydrocarbons and promote plant growth.

    PubMed

    Kukla, M; Płociniczak, T; Piotrowska-Seget, Z

    2014-12-01

    The aim of this study was to assess the ability of twenty-nine endophytic bacteria isolated from the tissues of ryegrass (Lolium perenne L.) to promote plant growth and the degradation of hydrocarbon. Most of the isolates belonged to the genus Pseudomonas and showed multiple plant growth-promoting abilities. All of the bacteria that were tested exhibited the ability to produce indole-3-acetic acid and were sensitive to streptomycin. These strains were capable of phosphate solubilization (62%), cellulolytic enzyme production (62%), a capacity for motility (55%) as well as for the production of siderophore (45%), ammonium (41%) and hydrogen cyanide (38%). Only five endophytes had the emulsification ability that results from the production of biosurfactants. The 1-aminocyclopropane-1-carboxylate deaminase (ACCD) gene (acdS) was found in ten strains. These bacteria exhibited ACCD activities in the range from 1.8 to 56.6 μmol of α-ketobutyrate mg(-1)h(-1), which suggests that these strains may be able to modulate ethylene levels and enhance plant growth. The potential for hydrocarbon degradation was assessed by PCR amplification on the following genes: alkH, alkB, C23O, P450 and pah. The thirteen strains that were tested had the P450 gene but the alkH and pah genes were found only in the Rhodococcus fascians strain (L11). Four endophytic bacteria belonging to Microbacterium sp. and Rhodococcus sp. (L7, S12, S23, S25) showed positive results for the alkB gene.

  18. Immunological cross-reactivity of the major allergen from perennial ryegrass (Lolium perenne), Lol p I, and the cysteine proteinase, bromelain.

    PubMed

    Pike, R N; Bagarozzi, D; Travis, J

    1997-04-01

    Antibodies prepared in rabbits against the major allergen from ryegrass (Lolium perenne), Lol p I, cross-reacted with the cysteine proteinase bromelain from pineapple and vice versa. Deglycosylation of the proteins showed that the cross-reaction was based on recognition of the carbohydrate moiety of the allergen, but for bromelain the cross-reaction was most likely due to a combination of factors. The results indicate that the carbohydrate residues from these allergens play an important role in cross-reactions found between them and possibly those from other species.

  19. Comparison of sensitivity of grasses (Lolium perenne L. and Festuca rubra L.) and lettuce (Lactuca sativa L.) exposed to water contaminated with microcystins.

    PubMed

    Pereira, Silvia; Saker, Martin L; Vale, Micaela; Vasconcelos, Vitor M

    2009-07-01

    The effects of aqueous extracts from Microcysts aeruginosa strains (both microcystin-producers and non-microcystin producers) on germination and root growth were investigated for three economically important plant species: Festuca rubra L., Lolium perenne L., and Lactuca sativa L. There was a clear inhibition of root growth for L. sativa exposed to strains containing microcystins (5.9-56.4 microg L(-1)). The strain that produced the most pronounced effects contained the lowest concentration of microcystin suggesting that other cellular compounds may also affect growth.

  20. Spatial Distribution of Bacterial Communities and Phenanthrene Degradation in the Rhizosphere of Lolium perenne L.

    PubMed Central

    Corgié, S. C.; Beguiristain, T.; Leyval, C.

    2004-01-01

    Rhizodegradation of organic pollutants, such as polycyclic aromatic hydrocarbons, is based on the effect of root-produced compounds, known as exudates. These exudates constitute an important and constant carbon source that selects microbial populations in the plant rhizosphere, modifying global as well as specific microbial activities. We conducted an experiment in two-compartment devices to show the selection of bacterial communities by root exudates and phenanthrene as a function of distance to roots. Using direct DNA extraction, PCR amplification, and thermal gradient gel electrophoresis screening, bacterial population profiles were analyzed in parallel to bacterial counts and quantification of phenanthrene biodegradation in three layers (0 to 3, 3 to 6, and 6 to 9 mm from root mat) of unplanted-polluted (phenanthrene), planted-polluted, and planted-unpolluted treatments. Bacterial community differed as a function of the distance to roots, in both the presence and the absence of phenanthrene. In the planted and polluted treatment, biodegradation rates showed a strong gradient with higher values near the roots. In the nonplanted treatment, bacterial communities were comparable in the three layers and phenanthrene biodegradation was high. Surprisingly, no biodegradation was detected in the section of planted polluted treatment farthest from the roots, where the bacterial community structure was similar to those of the nonplanted treatment. We conclude that root exudates and phenanthrene induce modifications of bacterial communities in polluted environments and spatially modify the activity of degrading bacteria. PMID:15184156

  1. An Epichloë festucae homologue of MOB3, a component of the STRIPAK complex, is required for the establishment of a mutualistic symbiotic interaction with Lolium perenne

    PubMed Central

    Green, Kimberly A.; Becker, Yvonne; Fitzsimons, Helen L.

    2016-01-01

    Summary In both Sordaria macrospora and Neurospora crassa, components of the conserved STRIPAK (striatin‐interacting phosphatase and kinase) complex regulate cell–cell fusion, hyphal network development and fruiting body formation. Interestingly, a number of Epichloë festucae genes that are required for hyphal cell–cell fusion, such as noxA, noxR, proA, mpkA and mkkA, are also required for the establishment of a mutualistic symbiotic interaction with Lolium perenne. To determine whether MobC, a homologue of the STRIPAK complex component MOB3 in S. macrospora and N. crassa, is required for E. festucae hyphal fusion and symbiosis, a mobC deletion strain was generated. The ΔmobC mutant showed reduced rates of hyphal cell–cell fusion, formed intrahyphal hyphae and exhibited enhanced conidiation. Plants infected with ΔmobC were severely stunted. Hyphae of ΔmobC showed a proliferative pattern of growth within the leaves of Lolium perenne with increased colonization of the intercellular spaces and vascular bundles. Although hyphae were still able to form expressoria, structures allowing the colonization of the leaf surface, the frequency of formation was significantly reduced. Collectively, these results show that the STRIPAK component MobC is required for the establishment of a mutualistic symbiotic association between E. festucae and L. perenne, and plays an accessory role in the regulation of hyphal cell–cell fusion and expressorium development in E. festucae. PMID:27277141

  2. [Enhancement of GA3 and EDTA on Lolium perenne to remediate Pb contaminated soil and its detoxification mechanism].

    PubMed

    Wu, Qiu-Ling; Wang, Wen-Chu; He, Shan-Ying

    2014-10-01

    A pot experiment was conducted to study the effects of plant growth regulator GA3 and metal chelate EDTA on enhancing the remediation of Pb contaminated soil, and the detoxification mechanism of Lolium perenne grown on Pb contaminated soil at 250 and 500 mg · kg(-1). The results showed that cell wall deposition and vacuolar compartmentalization played important roles in the detoxification of Pb in L. perenne shoot. The addition of EDTA alone increased Pb concentration in plants and Pb proportions in soluble fraction and organelles fraction, and enhanced the toxicity of Pb to plant, leading to the significant reduction of the plant biomass (P < 0.05). Foliar spray of lower concentration of GA3 (1 μmol · L(-1) or 10 μmol · L(-1)) alone significantly increased Pb accumulation by L. perenne (P < 0.05), but Pb proportions in soluble and organelles fraction were decreased, which alleviated the adverse effects of Pb on plant, thus improving the growth of plants (P < 0.05), with 1 μmol · L(-1) GA3 being the most effective. In contract, the addition of 100 μmol · L(-1) GA3 decreased Pb concentration in L. perenne, but increased the proportions of Pb in soluble fraction and organelles fraction, resulting in the reduction of plant biomass. Lower concen- tration of GA3 might alleviate the adverse effects of Pb and/or EDTA on plant, since the biomass amounts in the different treatments were in order of GA3 alone of lower concentration > GA3 of lower concentration + EDTA > EDTA alone. The combination application of low concentration of GA3 and EDTA showed a synergistic effect on the Pb accumulation in L. perenne (P < 0.05). Especially, Pb concentration in shoot and Pb extraction efficiency reached 1250.6 mg · kg(-1) and 1.1%, respec- tively, under the treatment of EDTA + 1 μmol L(-1) GA3 on the Pb 500 mg · kg(-1) soil. Therefore, the application of 1 μmol · L(-1) GA3 along with EDTA appeared to be a potential approach for phytoremediation of Pb contaminated soil.

  3. The annual variation in stomatal ammonia compensation point of rye grass ( Lolium perenne L.) leaves in an intensively managed grassland

    NASA Astrophysics Data System (ADS)

    van Hove, L. W. A.; Heeres, P.; Bossen, M. E.

    The stomatal ammonia compensation point for ammonia (NH 3) of an intensively managed pasture of rye grass ( Lolium perenne L.) was followed from mid January till November 2000. Leaf samples were taken every week. Simultaneously, the ambient NH 3 concentration was measured. Meteorological data (temperature, wind speed, rainfall and radiance) were collected from a nearby field station. The vacuum infiltration technique was used to isolate the apoplastic solution of the leaves. From the determined ammonium (NH 4+) concentration and pH in the apoplast, the gaseous NH 3 concentration inside the leaves was calculated, i.e. the so-called stomatal compensation point ( χs). Temperature appeared to have a predominant effect on χs, partly by affecting the equilibrium between gaseous NH 3 inside the leaf and NH 3 dissolved in the apoplast and partly by affecting physiological processes influencing the NH 4+ concentration in the apoplast. Results of the present study suggest that these temperature effects were counteracting. On one hand temperature increase during early spring stimulated NH 3 volatilisation from the apoplast, on the other hand it led to a decline in apoplastic NH 4+ from 0.9 to 0.2 mM, thereby diminishing the emission potential of the leaf. The low NH 4+ concentrations during spring and summer coincided with a low total leaf N content (<3% dw). However, there was no clear relationship between these two variables. The total N content of the leaf tissue is therefore an inadequate parameter for prediction of the potential NH 3 emission from rye grass leaves. No annual trend was found for the apoplast pH. With a few exceptions, pH varied between 5.9 and 6.5 throughout the experimental period. The calculated values for χs varied between 0.5 and 4 μg m -3. The gaseous NH 3 concentrations inside the grass leaves were, with a few exceptions, always smaller than the measured ambient NH 3 concentrations. The present study indicates that under the current ambient NH 3

  4. Evaluation of dissipation mechanisms by Lolium perenne L, and Raphanus sativus for pentachlorophenol (PCP) in copper co-contaminated soil.

    PubMed

    Lin, Qi; Wang, Zhaowei; Ma, Song; Chen, Yingxu

    2006-09-15

    Though phytoremediation is widely studied in remediation of metal contaminated soils or organic contaminated soils, little information is available regarding the effectiveness and processes of phytoremediation of sites co-contaminated with organic and metal pollutants. Sites co-contaminated with organic and metal pollutants are common and considered to be a more complex problem as the two components often cause a synergistic effect on cytotoxicity as measured both by growth inhibition and colony-forming ability. In this paper, the dissipation mechanisms for pentachlorophenol (PCP) in copper co-contaminated soil by Lolium perenne L, and Raphanus sativus was investigated in a greenhouse experiment by monitoring the growth response of plants, evaluating the removal efficiency of extractable PCP, differentiating PCP residuals in strongly and loosely adhering rhizosphere soils, and analyzing the microbial activity in the rhizosphere. In copper co-contaminated soil with the initial PCP concentration of 50 mg/kg, plants grew better with the increment of soil Cu level (0, 150, 300 mg/kg), which implied that combinations of inorganic and organic pollutants sometimes exerted antagonistic effects on plant cytotoxicity. The observed higher PCP dissipation in soil spiked with 50 mg/kg PCP in the presence of Cu and the less difference of PCP residual between strongly and loosely adhering soils further suggests the occurrence of Cu-PCP interaction and the enhanced degradation and mass flow are two possible explanations. In copper co-contaminated soil with the initial PCP concentration of 100 mg/kg, however, both plant growth and microbial activity were inhibited with the increment of soil Cu level. The lowered degrading activity of microorganisms and the reduced mass flow were probably responsible for the significantly lower levels of PCP dissipation in copper co-contaminated soil. These results showed that remediation of sites co-contaminated with organic and metal pollutants is

  5. Heavy-metal absorption by perennial ryegrass and Swiss chard grown in potted soils amended with ashes from 18 municipal refuse incinerators. [Lolium perenne; Beta vulgaris L

    SciTech Connect

    Bache, C.A.; Lisk, D.J. )

    1990-01-01

    Perennial ryegrass (Lolium perenne) and swiss chard (Beta vulgaris L.) were grown in pots of mardin silt loam soil amended with 5 or 10% by weight of fly ash, bottom ash, or mixtures of both from 18 municipal refuse incinerators representing about one-fourth of all those operating in the US. The ash and plant material were analyzed for total cadmium, lead, and zinc. The correlation coefficients (r) for the concentration of cadmium, lead, and zinc in the ashes and that in the following crops were, respectively, as follows: ryegrass (first cutting), 0.9964, 0.7600, 0.9699; ryegrass (second cutting), 0.9946, 0.6895, 0.9474; swiss chard, 0.9153, 0.7609., 0.9580. Poor plant growth occurred in a few of the treatments containing ash notably higher in dissolved solids, cadmium, and zinc. The origin and association of heavy metals in refuse ash and their reactions in soils are reviewed.

  6. Dynamics of 45S rDNA sites in the cell cycle: fragile sites and chromosomal stability in Lolium and Festuca.

    PubMed

    Rocha, L C; Silva, G A; Bustamante, F O; Silveira, R A D; Mittlemann, A; Techio, V H

    2017-01-23

    Analyses carried out with fluorescence in situ hybridization (FISH) in C-metaphases of the Lolium-Festuca complex have shown the occurrence of spontaneous fragile sites (FSs) in 45S rDNA regions. FSs are expressed as gaps but they do not result in breaks or chromosomal fragments in these species. These gaps have high DNA condensation observed as thin chromatin fibers that connect the apparent segments of the fragile chromosome, allowing for genomic stability. Assessing the behavior of these regions in the cell cycle of Lolium and Festuca species may lead to a better understanding of the dynamics that preserve stability during cell division. Furthermore, it is interesting to track the dynamics of chromosomes bearing 45S rDNA sites in the cell cycle as well as to observe the expression of FSs with no effect of the mitotic block. We observed variation in both the number and size of 45S FISH signals from the S/G2 phases of interphase and from prophase to anaphase where gaps in 45S rDNA sites also were observed. The change in the degree of condensation of the 45S site begins in the S/G2 phase and appears to be related to the transcriptional demand. Taking into account that the number of 45S rDNA sites tends to be re-established when cells reach telophase, we suggest that the chromatin fiber goes back to the normal condensation level to the anaphase (after segregation), allowing for the approximation of chromosome segments and ensuring dynamics that favor the genomic stability of these species.

  7. TSG (2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside) from the Chinese Herb Polygonum multiflorum Increases Life Span and Stress Resistance of Caenorhabditis elegans

    PubMed Central

    Büchter, Christian; Zhao, Liang; Fritz, Gerhard; Proksch, Peter

    2015-01-01

    2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG) was isolated from Polygonum multiflorum, a plant which is traditionally used as an anti-ageing drug. We have analysed ageing-related effects of TSG in the model organism C. elegans in comparison to resveratrol. TSG exerted a high antioxidative capacity both in a cell-free assay and in the nematode. The antioxidative capacity was even higher compared to resveratrol. Presumably due to its antioxidative effects, treatment with TSG decreased the juglone-mediated induction of the antioxidative enzyme SOD-3; the induction of the GST-4 by juglone was diminished slightly. TSG increased the resistance of C. elegans against lethal thermal stress more prominently than resveratrol (50 μM TSG increased mean survival by 22.2%). The level of the ageing pigment lipofuscin was decreased after incubation with the compound. TSG prolongs the mean, median, and maximum adult life span of C. elegans by 23.5%, 29.4%, and 7.2%, respectively, comparable to the effects of resveratrol. TSG-mediated extension of life span was not abolished in a DAF-16 loss-of-function mutant strain showing that this ageing-related transcription factor is not involved in the effects of TSG. Our data show that TSG possesses a potent antioxidative capacity, enhances the stress resistance, and increases the life span of the nematode C. elegans. PMID:26075030

  8. Mapping of T cell epitopes of the major fraction of rye grass using peripheral blood mononuclear cells from atopics and non-atopics. II. Isoallergen clone 5A of Lolium perenne group I (Lol p I).

    PubMed

    Bungy, G A; Rodda, S; Roitt, I; Brostoff, J

    1994-09-01

    Rye grass is the major cause of hay fever which currently affects 20% of the population. Lolium perenne group I (Lol p I) is a glycoprotein of 240 amino acid residues, representing the main allergen of rye grass. We have used peripheral blood mononuclear cells (PBMC) from controls and subjects allergic to rye grass and cultured them with L. perenne extract (LPE) and Lol p I and measured lymphocyte activation using thymidine incorporation. Patients were further studied against the 115 overlapping peptides of the iso-allergen clone 5A of Lol p I to see whether the 4 amino acid residue differences between clone 1A and clone 5A affect the T cell epitope and thus, lymphocyte activation. There are 24 peptide differences between isoallergen clone 1A and clone 5A occurring in pools 4, 13, 16 and 19 each one of which could be an immunodominant epitope. The PBMC from all allergic patients studied showed a strong proliferative response to LPE and Lol p I. Five immunogenic peptide pools, pool 6, 15, 16, 17 and 19 of the isoallergen clone 5A were also identified. Most of these pools are in the C-terminal region of Lol p I. Out of 20 pools tested in vitro 1 pool (pool-17) induced PBMC proliferation in five out of six patients who were not restricted to an HLA class II DR gene product. However, three out of the six subjects responded to various other peptide pools in addition to the immunodominant pool. In spite of the amino acid differences between the two clones, pool 17 still remains the immunodominant T cell epitope. Control subjects showed only weak responses to LPE and no detectable response to either Lol p I or peptide pools. From within the most active pool we have defined two peptides of the isoallergen clone 5A (identical in sequence with clone 1A) which stimulate lymphocytes from rye grass-sensitive patients in vitro. Previous studies with the two continuous sequences (193WGAVWRIDTPDK204 and 195AVWRIDTPDKLT206) tested in vivo by intradermal skin testing have shown

  9. Variations in efficiency of plastidial RNA editing within ndh transcripts of perennial ryegrass (Lolium perenne) are not linked to differences in drought tolerance

    PubMed Central

    Van Den Bekerom, Rob J. M.; Dix, Philip J.; Diekmann, Kerstin; Barth, Susanne

    2013-01-01

    Maintenance of healthy grasslands is essential for efficient livestock production, yet projected climate change is likely to place a heavy drought stress burden on key grassland species, such as perennial ryegrass (Lolium perenne). It is therefore important to gather an in-depth knowledge of the underlying plant response to this stress. The present study is focused on RNA editing (post-transcriptional nucleotide modifications resulting in altered transcripts) within plastidial transcripts of the NADH:ubiquinone oxidoreductase (NDH) complex (NADH dehydrogenase complex) in relation to the drought response of several accessions of perennial ryegrass. Previous studies have shown that the NDH complex is involved in countering oxidative stress during environmental stresses like drought. Owing to the nature of RNA editing within this complex, the RNA editing machinery could play a potential role in regulating the activity of the NDH complex. The investigation revealed dramatic and reproducible differences in RNA editing efficiency between accessions, but efficiency was not influenced by imposition of drought stress, and a direct relationship between editing behaviour and drought response was not detected.

  10. Effect of ryegrass (Lolium perenne L.) roots inoculation using different arbuscular mycorrhizal fungi (AMF) species on sorption of iron-cyanide (Fe-CN) complexes

    NASA Astrophysics Data System (ADS)

    Sut, Magdalena; Boldt-Burisch, Katja; Raab, Thomas

    2016-04-01

    Soils and groundwater on sites of the former Manufactured Gas Plants (MGPs) are contaminated with various complex iron-cyanides (Fe-CN). Phytoremediation is a promising tool in stabilization and remediation of Fe-CN affected soils, however, it can be a challenging task due to extreme adverse and toxic conditions. Phytoremediation may be enhanced via rhizosphere microbial activity, which can cooperate on the degradation, transformation and uptake of the contaminants. Recently, increasing number of scientist reports improved plants performance in the removal of toxic compounds with the support of arbuscular mycorrhizae fungi (AMF). Series of batch experiments using potassium hexacyanoferrate (II) solutions, in varying concentrations, were used to study the effect of ryegrass roots (Lolium perenne L.) inoculation with Rhizophagus irregularis and a mixture of Rhizophagus irregularis, Funneliformis mosseae, Rhizophagus aggregatus, and Claroideoglomus etunicatum on Fe-CN sorption. Results indicated significantly higher colonization of R. irregularis than for the mixture of AMF species on ryegrass roots. Sorption experiments revealed significantly higher reduction of total CN and free CN content in the mycorrhizal roots, indicating greater cyanide decrease in the treatment inoculated with R. irregularis. Our study indicates contribution of AM fungi in phytoremediation of Fe-CN contaminated soil.

  11. Effect of pre-grazing herbage mass on dairy cow performance, grass dry matter production and output from perennial ryegrass (Lolium perenne L.) pastures.

    PubMed

    Wims, C M; Delaby, L; Boland, T M; O'Donovan, M

    2014-01-01

    A grazing study was undertaken to examine the effect of maintaining three levels of pre-grazing herbage mass (HM) on dairy cow performance, grass dry matter (DM) production and output from perennial ryegrass (Lolium perenne L.) pastures. Cows were randomly assigned to one of three pre-grazing HM treatments: 1150 - Low HM (L), 1400 - Medium HM (M) or 2000 kg DM/ha - High HM (H). Herbage accumulation under grazing was lowest (P<0.01) on the L treatment and cows grazing the L pastures required more grass silage supplementation during the grazing season (+73 kg DM/cow) to overcome pasture deficits due to lower pasture growth rates (P<0.05). Treatment did not affect daily milk production or pasture intake, although cows grazing the L pastures had to graze a greater daily area (P<0.01) and increase grazing time (P<0.05) to compensate for a lower pre-grazing HM (P<0.01). The results indicate that, while pre-grazing HM did not influence daily milk yield per cow, adapting the practise of grazing low HM (1150 kg DM/ha) pasture reduces pasture DM production and at a system level may increase the requirement for imported feed.

  12. Dark-mediated dormancy release in stratified Lolium rigidum seeds is associated with higher activities of cell wall-modifying enzymes and an apparent increase in gibberellin sensitivity.

    PubMed

    Goggin, Danica E; Powles, Stephen B; Toorop, Peter E; Steadman, Kathryn J

    2011-04-15

    Dormancy release in freshly matured, imbibed annual ryegrass (Lolium rigidum) seeds is inhibited by light and involves a decrease in seed sensitivity to abscisic acid. Other processes involved in dormancy release in the dark were investigated by measuring seed storage compound mobilisation and the activity of cell wall-degrading enzymes. Activities of endo-β-mannanase and total peroxidase were higher in dark-stratified compared to light-stratified seeds, indicating that weakening of the structures constraining the embryo was accelerated in the dark. A dramatic degradation of storage proteins in light-stratified seeds, accompanied by induction of a high molecular mass protease, suggests that maintenance of storage(-like) proteins is also important in dark-mediated dormancy release. α-Amylase activity was induced in dark-stratified seeds at least 48 h prior to radicle emergence upon transfer to conditions permitting germination, or in light-stratified seeds supplied with exogenous gibberellin A(4). This suggests that (a) α-amylase is involved in stimulation of germination of non-dormant L. rigidum seeds, and (b) dark-stratified seeds have an increased sensitivity to gibberellins which permits the rapid induction of α-amylase activity upon exposure to germination conditions. Overall, it appears that a number of processes, although possibly minor in themselves, occur in concert during dark-stratification to contribute to dormancy release. Copyright © 2010 Elsevier GmbH. All rights reserved.

  13. Effect of herbicide resistance endowing Ile-1781-Leu and Asp-2078-Gly ACCase gene mutations on ACCase kinetics and growth traits in Lolium rigidum

    PubMed Central

    Vila-Aiub, Martin M.; Yu, Qin; Han, Heping; Powles, Stephen B.

    2015-01-01

    The rate of herbicide resistance evolution in plants depends on fitness traits endowed by alleles in both the presence and absence (resistance cost) of herbicide selection. The effect of two Lolium rigidum spontaneous homozygous target-site resistance-endowing mutations (Ile-1781-Leu, Asp-2078-Gly) on both ACCase activity and various plant growth traits have been investigated here. Relative growth rate (RGR) and components (net assimilation rate, leaf area ratio), resource allocation to different organs, and growth responses in competition with a wheat crop were assessed. Unlike plants carrying the Ile-1781-Leu resistance mutation, plants homozygous for the Asp-2078-Gly mutation exhibited a significantly lower RGR (30%), which translated into lower allocation of biomass to roots, shoots, and leaves, and poor responses to plant competition. Both the negligible and significant growth reductions associated, respectively, with the Ile-1781-Leu and Asp-2078-Gly resistance mutations correlated with their impact on ACCase activity. Whereas the Ile-1781-Leu mutation showed no pleiotropic effects on ACCase kinetics, the Asp-2078-Gly mutation led to a significant reduction in ACCase activity. The impaired growth traits are discussed in the context of resistance costs and the effects of each resistance allele on ACCase activity. Similar effects of these two particular ACCase mutations on the ACCase activity of Alopecurus myosuroides were also confirmed. PMID:26019257

  14. Human immune responsiveness to Lolium perenne pollen allergen Lol p III (rye III) is associated with HLA-DR3 and DR5.

    PubMed

    Ansari, A A; Freidhoff, L R; Meyers, D A; Bias, W B; Marsh, D G

    1989-05-01

    A well-characterized allergen of Lolium perenne (perennial rye grass) pollen, Lol p III, has been used as a model antigen to study the genetic control of the human immune response. Associations between HLA type and IgE or IgG antibody (Ab) responsiveness to Lol p III were studied in two groups of skin-test-positive Caucasoid adults (N = 135 and 67). We found by nonparametric and parametric analyses that immune responsiveness to Lol p III was significantly associated with HLA-DR3 and DR5. No association was found between any DQ type and immune responsiveness to Lol p III. Geometric mean IgE or IgG Ab levels to Lol p III were not different between B8+, DR3+ subjects and B8-, DR3+ subjects, showing that HLA-B8 had no influence on the association. Lol p III IgG Ab data obtained on subjects after grass antigen immunotherapy showed that 100% of DR3 subjects and 100% of DR5 subjects were Ab+. A comparison of all the available protein sequences of DRB gene products showed that the first hypervariable region of DR3 and DR5 (and DRw6), and no other region, contains the sequence Glu9-Tyr-Ser-Thr-Ser13. Our observations are consistent with the possibility that immune responsiveness to the allergen Lol p III is associated with this amino acid sequence in the first hypervariable region of the DR beta 1 polypeptide chain.

  15. Complete primary structure of a Lolium perenne (perennial rye grass) pollen allergen, Lol p III: comparison with known Lol p I and II sequences.

    PubMed

    Ansari, A A; Shenbagamurthi, P; Marsh, D G

    1989-10-17

    The complete amino acid sequence of a Lolium perenne (rye grass) pollen allergen, Lol p III, determined by the automated Edman degradation of the protein and its selected fragments, is reported in this paper. Cleavage by enzymatic and chemical techniques established unambiguously the sequence for this 97-residue protein (Mr = 10,909), which lacks cysteine and shows no evidence of glycosylation. The sequence of Lol p III is very similar to that of another L. perenne allergen, Lol p II, which was sequenced recently; of the 97 positions in the two proteins, 57 are occupied by identical amino acids (59% identity). In addition, both allergens share a similar structure with an antibody-binding fragment of a third L. perenne allergen, Lol p I. Since human antibody responsiveness to all these three allergens is associated with HLA-DR3, and since the structure common to the three molecules shows high degrees of amphipathicity in Lol p II and III, we speculate that this common segment in the three molecules might contain or contribute to the respectively Ia/T-cell sites.

  16. Effect of herbicide resistance endowing Ile-1781-Leu and Asp-2078-Gly ACCase gene mutations on ACCase kinetics and growth traits in Lolium rigidum.

    PubMed

    Vila-Aiub, Martin M; Yu, Qin; Han, Heping; Powles, Stephen B

    2015-08-01

    The rate of herbicide resistance evolution in plants depends on fitness traits endowed by alleles in both the presence and absence (resistance cost) of herbicide selection. The effect of two Lolium rigidum spontaneous homozygous target-site resistance-endowing mutations (Ile-1781-Leu, Asp-2078-Gly) on both ACCase activity and various plant growth traits have been investigated here. Relative growth rate (RGR) and components (net assimilation rate, leaf area ratio), resource allocation to different organs, and growth responses in competition with a wheat crop were assessed. Unlike plants carrying the Ile-1781-Leu resistance mutation, plants homozygous for the Asp-2078-Gly mutation exhibited a significantly lower RGR (30%), which translated into lower allocation of biomass to roots, shoots, and leaves, and poor responses to plant competition. Both the negligible and significant growth reductions associated, respectively, with the Ile-1781-Leu and Asp-2078-Gly resistance mutations correlated with their impact on ACCase activity. Whereas the Ile-1781-Leu mutation showed no pleiotropic effects on ACCase kinetics, the Asp-2078-Gly mutation led to a significant reduction in ACCase activity. The impaired growth traits are discussed in the context of resistance costs and the effects of each resistance allele on ACCase activity. Similar effects of these two particular ACCase mutations on the ACCase activity of Alopecurus myosuroides were also confirmed.

  17. Genome-Wide Transcriptional Profiling and Metabolic Analysis Uncover Multiple Molecular Responses of the Grass Species Lolium perenne Under Low-Intensity Xenobiotic Stress

    PubMed Central

    Serra, Anne-Antonella; Couée, Ivan; Heijnen, David; Michon-Coudouel, Sophie; Sulmon, Cécile; Gouesbet, Gwenola

    2015-01-01

    Lolium perenne, which is a major component of pastures, lawns, and grass strips, can be exposed to xenobiotic stresses due to diffuse and residual contaminations of soil. L. perenne was recently shown to undergo metabolic adjustments in response to sub-toxic levels of xenobiotics. To gain insight in such chemical stress responses, a de novo transcriptome analysis was carried out on leaves from plants subjected at the root level to low levels of xenobiotics, glyphosate, tebuconazole, and a combination of the two, leading to no adverse physiological effect. Chemical treatments influenced significantly the relative proportions of functional categories and of transcripts related to carbohydrate processes, to signaling, to protein-kinase cascades, such as Serine/Threonine-protein kinases, to transcriptional regulations, to responses to abiotic or biotic stimuli and to responses to phytohormones. Transcriptomics-based expressions of genes encoding different types of SNF1 (sucrose non-fermenting 1)-related kinases involved in sugar and stress signaling or encoding key metabolic enzymes were in line with specific qRT-PCR analysis or with the important metabolic and regulatory changes revealed by metabolomic analysis. The effects of pesticide treatments on metabolites and gene expression strongly suggest that pesticides at low levels, as single molecule or as mixture, affect cell signaling and functioning even in the absence of major physiological impact. This global analysis of L. perenne therefore highlighted the interactions between molecular regulation of responses to xenobiotics, and also carbohydrate dynamics, energy dysfunction, phytohormones and calcium signaling. PMID:26734031

  18. Stable isotope tracing: a powerful tool for selenium speciation and metabolic studies in non-hyperaccumulator plants (ryegrass Lolium perenne L.).

    PubMed

    Di Tullo, Pamela; Versini, Antoine; Bueno, Maïté; Le Hécho, Isabelle; Thiry, Yves; Biron, Philippe; Castrec-Rouelle, Maryse; Pannier, Florence

    2015-12-01

    Selenium is both essential and toxic for mammals; the range between the two roles is narrow and not only dose-dependent but also related to the chemical species present in foodstuff. Unraveling the metabolism of Se in plants as a function of Se source may thus lead to ways to increase efficiency of fertilization procedures in selenium deficient regions. In this study, stable-isotope tracing was applied for the first time in plants to simultaneously monitor the bio-incorporation of two inorganic Se species commonly used as foodstuff enrichment sources. Occurrence and speciation of Se coming from different Se sources were investigated in root and leaf extracts of ryegrass (Lolium perenne L.), which had been co-exposed to two labeled Se species ((77)SeIV and (82)SeVI). Although the plant absorbed similar amounts of Se when supplied in the form of selenite or selenate, the results evidenced marked differences in speciation and tissues allocation. Selenite was converted into organic forms incorporated mostly into high molecular weight compounds with limited translocation to leaves, whereas selenate was highly mobile being little assimilated into organic forms. Double-spike isotopic tracer methodology makes it possible to compare the metabolism of two species-specific Se sources simultaneously in a single experiment and to analyze Se behavior in not-hyperaccumulator plants, the ICP-MS sensitivity being improved by the use of enriched isotopes.

  19. Nitrogen deficiency inhibits leaf blade growth in Lolium perenne by increasing cell cycle duration and decreasing mitotic and post-mitotic growth rates.

    PubMed

    Kavanová, Monika; Lattanzi, Fernando Alfredo; Schnyder, Hans

    2008-06-01

    Nitrogen deficiency severely inhibits leaf growth. This response was analysed at the cellular level by growing Lolium perenne L. under 7.5 mM (high) or 1 mM (low) nitrate supply, and performing a kinematic analysis to assess the effect of nitrogen status on cell proliferation and cell growth in the leaf blade epidermis. Low nitrogen supply reduced leaf elongation rate (LER) by 43% through a similar decrease in the cell production rate and final cell length. The former was entirely because of a decreased average cell division rate (0.023 versus 0.032 h(-1)) and thus longer cell cycle duration (30 versus 22 h). Nitrogen status did not affect the number of division cycles of the initial cell's progeny (5.7), and accordingly the meristematic cell number (53). Meristematic cell length was unaffected by nitrogen deficiency, implying that the division and mitotic growth rates were equally impaired. The shorter mature cell length arose from a considerably reduced post-mitotic growth rate (0.033 versus 0.049 h(-1)). But, nitrogen stress did not affect the position where elongation stopped, and increased cell elongation duration. In conclusion, nitrogen deficiency limited leaf growth by increasing the cell cycle duration and decreasing mitotic and post-mitotic elongation rates, delaying cell maturation.

  20. Wood pellet fly ash and bottom ash as an effective liming agent and nutrient source for rye grass (Lolium perenne L.) and oats (Avena sativa).

    PubMed

    Park, Nathan D; Michael Rutherford, P; Thring, Ronald W; Helle, Steve S

    2012-01-01

    Fly ash (FA) and bottom ash (BA) from a softwood pellet boiler were characterized and evaluated as soil amendments. In a greenhouse study, two plant species (rye grass, Lolium perenne L. and oats, Avena sativa) were grown in three different treatments (1% FA, 1% BA, non-amended control) of a silty loam soil. Total concentrations of plant nutrients Ca, K, Mg, P and Zn in both ashes were elevated compared to conventional wood ash. Concentrations of Cd, Cr, Pb, Se and Zn were found to be elevated in the FA relative to BA and the non-amended soil. At 28 d, oat above-ground biomass was found to be significantly greater in soil amended with FA. Potassium and Mo plant tissue concentrations were significantly increased by addition of either ash, and FA significantly increased Zn tissue concentrations. Cadmium and Hg tissue concentrations were elevated in some cases. As soil amendments, either pellet ash is an effective liming agent and nutrient source, but high concentrations of Cd and Zn in FA may preclude its use as an agricultural soil amendment in some jurisdictions. Lower ash application rates than those used in this study (i.e. <1%) may still provide sufficient nutrients and effective neutralization of soil acidity.

  1. Fungal inoculation and elevated CO2 mediate growth of Lolium mutiforum and Phytolacca americana, metal uptake, and metal bioavailability in metal-contaminated soil: evidence from DGT measurement.

    PubMed

    Song, Ningning; Wang, Fangli; Zhang, Changbo; Tang, Shirong; Guo, Junkang; Ju, Xuehai; Smith, Donald L

    2013-01-01

    Fungal inoculation and elevated CO2 may mediate plant growth and uptake of heavy metals, but little evidence from Diffusive Gradients in Thin-films (DGT) measurement has been obtained to characterize the process. Lolium mutiforum and Phytolacca americana were grown at ambient and elevated CO2 on naturally Cd and Pb contaminated soils inoculated with and without Trichoderma asperellum strain C3 or Penicillium chrysogenum strain D4, to investigate plant growth, metal uptake, and metal bioavailability responses. Fungal inoculation increased plant biomass and shoot/root Cd and Pb concentrations. Elevated CO2 significantly increased plants biomass, but decreased Cd and Pb concentrations in shoot/root to various extents, leading to a metal dilution phenomenon. Total Cd and Pb uptake by plants, and DGT-measured Cd and Pb concentrations in rhizosphere soils, were higher in all fungal inoculation and elevated CO2 treatments than control treatments, with the combined treatments having more influence than either treatment alone. Metal dilution phenomenon occurred because the increase in DGT-measured bioavailable metal pools in plant rhizosphere due to elevated CO2 was unable to match the increase in requirement for plant uptake of metals due to plant biomass increase.

  2. Genome-Wide Transcriptional Profiling and Metabolic Analysis Uncover Multiple Molecular Responses of the Grass Species Lolium perenne Under Low-Intensity Xenobiotic Stress.

    PubMed

    Serra, Anne-Antonella; Couée, Ivan; Heijnen, David; Michon-Coudouel, Sophie; Sulmon, Cécile; Gouesbet, Gwenola

    2015-01-01

    Lolium perenne, which is a major component of pastures, lawns, and grass strips, can be exposed to xenobiotic stresses due to diffuse and residual contaminations of soil. L. perenne was recently shown to undergo metabolic adjustments in response to sub-toxic levels of xenobiotics. To gain insight in such chemical stress responses, a de novo transcriptome analysis was carried out on leaves from plants subjected at the root level to low levels of xenobiotics, glyphosate, tebuconazole, and a combination of the two, leading to no adverse physiological effect. Chemical treatments influenced significantly the relative proportions of functional categories and of transcripts related to carbohydrate processes, to signaling, to protein-kinase cascades, such as Serine/Threonine-protein kinases, to transcriptional regulations, to responses to abiotic or biotic stimuli and to responses to phytohormones. Transcriptomics-based expressions of genes encoding different types of SNF1 (sucrose non-fermenting 1)-related kinases involved in sugar and stress signaling or encoding key metabolic enzymes were in line with specific qRT-PCR analysis or with the important metabolic and regulatory changes revealed by metabolomic analysis. The effects of pesticide treatments on metabolites and gene expression strongly suggest that pesticides at low levels, as single molecule or as mixture, affect cell signaling and functioning even in the absence of major physiological impact. This global analysis of L. perenne therefore highlighted the interactions between molecular regulation of responses to xenobiotics, and also carbohydrate dynamics, energy dysfunction, phytohormones and calcium signaling.

  3. The photosynthetic acclimation response of Lolium perenne to four years growth in a free-air CO{sub 2} enrichment (FACE) facility

    SciTech Connect

    Creasey, R.

    1996-11-01

    In this study, the photosynthetic responses of field grown Lolium perenne to ambient (354 {mu}mol mol{sup -1}) and elevated (600 {mu}mol mol{sup -1}) C{sub a} were measured. The experiment utilized the FACE facility at Eschikon, Switzerland; here the L. Perenne swards had been grown at two nitrogen treatments, with six cuts per year, for 4 years. The study revealed a significant decrease in Rubisco activity (Vcmax) in the low nitrogen FACE plots; this is consistent with the theories of source-sink imbalance resulting in feedback inhibition and down-regulation. Such negative acclimation was not wholly supported by diurnal investigations which revealed an average stimulation of 53.38% and 52.78% in the low and high nitrogen, respectively. However, light response curves and AI investigations also suggested down-regulation, especially in the low nitrogen. SI is expected to decrease in response to elevated C{sub a}, if any change is seen. This was indeed observed in the high nitrogen plots but for the low nitrogen a significant increase was found. Conclusions drawn from this project center around the implications of negative acclimation to future crop productivity. For instance, inter-specific differences in response to elevated C{sub a} may result in ecosystem changes and new management techniques may be necessary. However, real predictions cannot be made from leaf level studies alone as these may not represent the overall changes at the whole plant level.

  4. Functional Analyses of Caffeic Acid O-Methyltransferase and Cinnamoyl-CoA-Reductase Genes from Perennial Ryegrass (Lolium perenne)[W

    PubMed Central

    Tu, Yi; Rochfort, Simone; Liu, Zhiqian; Ran, Yidong; Griffith, Megan; Badenhorst, Pieter; Louie, Gordon V.; Bowman, Marianne E.; Smith, Kevin F.; Noel, Joseph P.; Mouradov, Aidyn; Spangenberg, German

    2010-01-01

    Cinnamoyl CoA-reductase (CCR) and caffeic acid O-methyltransferase (COMT) catalyze key steps in the biosynthesis of monolignols, which serve as building blocks in the formation of plant lignin. We identified candidate genes encoding these two enzymes in perennial ryegrass (Lolium perenne) and show that the spatio-temporal expression patterns of these genes in planta correlate well with the developmental profile of lignin deposition. Downregulation of CCR1 and caffeic acid O-methyltransferase 1 (OMT1) using an RNA interference–mediated silencing strategy caused dramatic changes in lignin level and composition in transgenic perennial ryegrass plants grown under both glasshouse and field conditions. In CCR1-deficient perennial ryegrass plants, metabolic profiling indicates the redirection of intermediates both within and beyond the core phenylpropanoid pathway. The combined results strongly support a key role for the OMT1 gene product in the biosynthesis of both syringyl- and guaiacyl-lignin subunits in perennial ryegrass. Both field-grown OMT1-deficient and CCR1-deficient perennial ryegrass plants showed enhanced digestibility without obvious detrimental effects on either plant fitness or biomass production. This highlights the potential of metabolic engineering not only to enhance the forage quality of grasses but also to produce optimal feedstock plants for biofuel production. PMID:20952635

  5. Effect of elevated CO₂ and temperature on the oxidative stress response to drought in Lolium perenne L. and Medicago sativa L.

    PubMed

    Farfan-Vignolo, Evelyn Roxana; Asard, Han

    2012-10-01

    Studies addressing the combined impact of multiple climate factors on plant abiotic stress responses are still scarce. We investigated physiological and molecular (antioxidant), responses to water deficit, in grassland-model species, Lolium perenne L. and Medicago lupulina L., under future climate conditions, i.e. elevated CO₂ (+CO₂, +375 ppm) and elevated temperature (+T, +3 °C). Elevated CO₂, but not warming, significantly increased biomass (gDW) in L. perenne, but not in M. lupulina. Photosynthesis (A(sat)) and stomatal conductance (g(s)), were differently affected by climate in each species, L. perenne generally being more sensitive. Elevated CO₂ increased lipid peroxidation levels in M. lupulina, but not in L. perenne, and had no effect on protein oxidation and little effect on antioxidant levels. Drought stress caused severe inhibition in biomass and photosynthesis, most severely in L. perenne, and strongly increased oxidative damage. Elevated CO₂ protected against the drought-induced damage. Decreased activities of APX and POX may indicate lower levels of oxidative challenge (relaxation) at the level of H₂O₂ production. Polyphenols, tocopherols and antioxidant capacity, increased under drought stress, in all climate conditions. Elevated CO₂, increased reduced ascorbate (ASC) and reduced glutathione (GSH), and their redox status, in both species, although to different levels. Changes in activities of key ASC/GSH cycle enzymes, under stress and climate treatments, showed weak correlations with ASC and GSH levels, indicating the complexity of this network. Together this work supports the idea that redox changes are involved in responses to climate changes, in the absence and presence of water-deficit stress.

  6. Study of the epitope structure of purified Dac G I and Lol p I, the major allergens of Dactylis glomerata and Lolium perenne pollens, using monoclonal antibodies.

    PubMed

    Mourad, W; Mécheri, S; Peltre, G; David, B; Hébert, J

    1988-11-15

    The use of mAb allowed us to further analyze the cross-reactivity between purified Dac g I and Lol p I, the major allergens of Dactylis glomerata (cocksfoot) and Lolium perenne (Rye grass), respectively. It was first shown, using IEF, followed by immunoprinting, that serum IgE antibodies from most grass-sensitive patients recognize both Dac g I and Lol p I. Second, three different anti-Lol p I mAb, 290A-167, 348A-6, and 539A-6, and one anti-Dac g I mAb, P3B2 were all shown to react with Dac g I and Lol p I, indicating that the two molecules share common epitopes. Epitope specificity of the mAb was determined by competitive binding inhibition of a given labeled mAb to solid phase fixed Dac g I or Lol p I by the mAb. The results indicated that the four mAb are directed against four different and non-overlapping epitopes present on both allergens. Using double-binding RIA, our data strongly suggest that the common epitopes are not repetitive on both molecules. In addition to their similar physicochemical characteristics, such as isolectric points and m.w., Dac g I and Lol p I share four identical epitopes. Binding inhibition of human IgE to Lol p I and Dac g I by the mAb was also assessed. The results indicated that each mAb was able to inhibit such reactions to variable degree but no additive inhibition was observed when two mAb of different specificities were used in combination, suggesting that the human IgE binding site is partially shared by each epitope recognized by the four mAb.

  7. Cloning, gene mapping, and functional analysis of a fructan 1-exohydrolase (1-FEH) from Lolium perenne implicated in fructan synthesis rather than in fructan mobilization.

    PubMed

    Lothier, Jérémy; Lasseur, Bertrand; Le Roy, Katrien; Van Laere, André; Prud'homme, Marie-Pascale; Barre, Philippe; Van den Ende, Wim; Morvan-Bertrand, Annette

    2007-01-01

    Fructans, which are beta-(2,1) and/or beta-(2,6) linked polymers of fructose, are important storage carbohydrates in many plants. They are mobilized via fructan exohydrolases (FEHs). The cloning, mapping, and functional analysis of the first 1-FEH (EC 3.2.1.153) from Lolium perenne L. var. Bravo is described here. By screening a perennial ryegrass cDNA library, a 1-FEH cDNA named Lp1-FEHa was cloned. The Lp1-FEHa deduced protein has a low iso-electric point (5.22) and it groups together with plant FEHs and cell-wall type invertases. The deduced amino acid sequence shows 75% identity to wheat 1-FEH w2. The Lp1-FEHa gene was mapped at a distal position on the linkage group 3 (LG3). Functional characterization of the recombinant protein in Pichia pastoris demonstrated that it had high FEH activity towards 1-kestotriose, 1,1-kestotetraose, and inulin, but low activity against 6-kestotriose and levan. Like other fructan-plant FEHs, no hydrolase activity could be detected towards sucrose, convincingly demonstrating that the enzyme is not a classic invertase. The expression pattern analysis of Lp1-FEHa revealed transcript accumulation in leaf tissues accumulating fructans while transcript level was low in the photosynthetic tissues. The high expression level of this 1-FEH in conditions of active fructan synthesis, together with its low expression level when fructan contents are low, suggest that it might play a role as a beta-(2,1) trimming enzyme acting during fructan synthesis in concert with fructan synthesis enzymes.

  8. Responses of antioxidant gene, protein and enzymes to salinity stress in two genotypes of perennial ryegrass (Lolium perenne) differing in salt tolerance.

    PubMed

    Hu, Longxing; Li, Huiying; Pang, Huangcheng; Fu, Jinmin

    2012-01-15

    Salinity could damage cellular membranes through overproduction of reactive oxygen species (ROS), while antioxidant capacities play a vital role in protecting plants from salinity caused oxidative damages. The objective of this study was to investigate the toxic effect of salt on the antioxidant enzyme activities, isoforms and gene expressions in perennial ryegrass (Lolium perenne L.). Salt-tolerant 'Quickstart II' and salt-sensitive 'DP1' were subjected to 0 and 250 mM NaCl for 12 d. Salt stress increased the content of lipid peroxidation (MDA), electrolyte leakage (EL) and hydrogen peroxide (H₂O₂), to a greater extent in salt-sensitive genotype. Salt-stressed plant leaves exhibited a greater activity of superoxide dismutase (SOD, EC 1.15.1.1), peroxidase (POD, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11) at 4d after treatment (DAT), but a lower level of enzyme activity at 8 and 12d, when compared to the control. Catalase (CAT, EC 1.11.1.6) activity was greater at 4 DAT and thereafter decreased in salt tolerant genotype relative to the control, whereas lower than the control during whole experiment period for salt-sensitive genotype. There were different patterns of five isoforms of SOD, POD and two isoforms of APX between two genotypes. Antioxidant gene expression was positively related to isoenzymatic and total enzymatic activities during 12-d salt-treated leaves of two genotypes, with a relatively higher level in salt-tolerant genotype. Thus, salt tolerance could be related to the constitutive/induced antioxidant gene, leading to more efficient enzyme stimulation and protection in perennial ryegrass.

  9. Competition for water between walnut seedlings (Juglans regia) and rye grass (Lolium perenne) assessed by carbon isotope discrimination and delta18O enrichment.

    PubMed

    Picon-Cochard, C; Nsourou-Obame, A; Collet, C; Guehl, J M; Ferhi, A

    2001-02-01

    Container-grown walnut seedlings (Juglans regia L.) were subjected to competition with rye grass (Lolium perenne L.) and to a 2-week soil drying cycle. One and 2 weeks after the beginning of the drought treatment, H2 18O (delta approximately equals +100%) was added to the bottom layer of soil in the plant containers to create a vertical H2 18O gradient. Rye grass competition reduced aboveground and belowground biomass of the walnut seedlings by 60%, whereas drought had no effect. The presence of rye grass reduced the dry weight of walnut roots in the upper soil layer and caused a 50% reduction in lateral root length. Rye grass competition combined with the drought treatment reduced walnut leaf CO2 assimilation rate (A) and leaf conductance (gw) by 20 and 39%, respectively. Transpiration rates in rye grass, both at the leaf level and at the plant or tiller level, were higher than in walnut seedlings. Leaf intrinsic water-use efficiency (A/gw) of walnut seedlings increased in response to drought and no differences were observed between the single-species and mixed-species treatments, as confirmed by leaf carbon isotope discrimination measurements. Measurement of delta18O in soil and in plant xylem sap indicated that the presence of rye grass did not affect the vertical profile of soil water uptake by walnut seedlings. Walnut seedlings and rye grass withdrew water from the top and middle soil layers in well-watered conditions, whereas during the drought treatment, walnut seedlings obtained water from all soil layers, but rye grass took up water from the bottom soil layer only.

  10. The photosynthetic response of the perennial ryegrass (Lolium perenne) in its fifth year of free-air CO(sub 2) enrichment (FACE) at Eschikon, Switzerland

    SciTech Connect

    Anderson, J.P.; Long, S.P.; Williams, J.

    1998-12-31

    Stands of Ryegrass (Lolium perenne L. cv.Bastion) were grown in the field at ambient or elevated (600 {micro}mol mol{sup {minus}1}) [CO{sub 2}], high (560 kg Ha{sup {minus}1} y{sup {minus}1}) or low (140 kg Ha{sup {minus}1} y{sup {minus}1}) nitrogen addition and were harvested five times a year during the growing season. The plants were sown during 1992, additional plots being sown during 1995. These were in their fifth year and second year of growth respectively. Exposure to elevated [CO{sub 2}] was carried out with a Free-Air CO{sub 2} Enrichment (FACE) system which provides the most realistic system of fumigation currently available. Elevated [CO{sub 2}] increased diurnal CO{sub 2} uptake by between 40 to 83% while reducing stomatal conductance by between 1 and 38% in all of the 1992 grown plants measured at high [CO{sub 2}]. Analysis of the A/c{sub i} response of 1992 grown plants showed no acclimation of the photosynthetic apparatus in response to elevated [CO{sub 2}] - both V{sub c,max} (a measure of the maximum in vivo rate of carboxylation) and J{sub max} (a measure of the maximum capacity for the regeneration of RuBP) showed no significant change during any of the periods of regrowth. In contrast the leaves of 1995 grown plants, appeared to be experiencing an acclimatory change in their photosynthetic apparatus in response to elevated [CO{sub 2}]. However, this negative response seemed to be removed directly after a harvest when the source:sink balance had increased. The apparent lack of an acclimatory response after almost 5 years of growth at elevated [CO{sub 2}], suggests that L. perenne may be close to achieving the appropriate photosynthetic adjustments which would allow it to attain a significantly higher photosynthetic potential.

  11. THE PHOTOSYNTHETIC RESPONSE OF THE PERENNIAL RYEGRASS (LOLIUM PERENNE) IN ITS FIFTH YEAR OF FREE-AIR CO{sub 2} ENRICHMENT (FACE) AT ESCHIKON, SWITZERLAND

    SciTech Connect

    ANDERSON,J.P.; LONG,STEPHEN,P.; WILLIAMS,J.

    1998-12-31

    Stands of Ryegrass (Lolium perenne L. cv.Bastion) were grown in the field at ambient or elevated (600 {micro}mol mol{sup {minus}1}) [CO{sub 2}], high (560 kg Ha{sup {minus}1} y{sup {minus}1}) or low (140 kg Ha{sup {minus}1} y{sup {minus}1}) nitrogen addition and were harvested five times a year during the growing season. The plants were sown during 1992, additional plots being sown during 1995. These were in their fifth year and second year of growth respectively. Exposure to elevated [CO{sub 2}] was carried out with a Free-Air CO{sub 2} Enrichment (FACE) system which provides the most realistic system of fumigation currently available. Elevated [CO{sub 2}] increased diurnal CO{sub 2} uptake by between 40 to 83% while reducing stomatal conductance by between 1 and 38% in all of the 1992 grown plants measured at high [CO{sub 2}]. Analysis of the A/c{sub i} response of 1992 grown plants showed no acclimation of the photosynthetic apparatus in response to elevated [CO{sub 2}]--both V{sub c,max} (a measure of the maximum in vivo rate of carboxylation) and J{sub max} (a measure of the maximum capacity for the regeneration of RuBP) showed no significant change during any of the periods of regrowth. In contrast the leaves of 1995 grown plants, appeared to be experiencing an acclimatory change in their photosynthetic apparatus in response to elevated [CO{sub 2}]. However, this negative response seemed to be removed directly after a harvest when the source:sink balance had increased. The apparent lack of an acclimatory response after almost 5 years of growth at elevated [CO{sub 2}], suggests that L. perenne may be close to achieving the appropriate photosynthetic adjustments which would allow it to attain a significantly higher photosynthetic potential.

  12. Effect of DA-6 and EDTA alone or in combination on uptake, subcellular distribution and chemical form of Pb in Lolium perenne.

    PubMed

    He, Shanying; Wu, Qiuling; He, Zhenli

    2013-11-01

    The effects of growth-promoting hormone diethyl aminoethyl hexanoate (DA-6) and EDTA, either alone or in combination applied to original soil or lead (Pb) spiked soil on Pb phytoextraction, subcellular distribution and chemical forms in Lolium perenne were studied. EDTA addition alone significantly reduced plant biomass though it increased Pb accumulation (P<0.05). Foliar spray of DA-6 alone increased both plant biomass and Pb accumulation (P<0.05), with 10μM DA-6 being the most effective. DA-6 combined with EDTA compensated the adverse effect of the latter on plant growth, and resulted in a synergistic effect on Pb uptake and translocation, with the maximum accumulation occurring in the EDTA+10μM DA-6 treatment. At the subcellular level, about 35-66% of Pb was distributed in cell wall and 21-42% in soluble fraction, with a minority present in cellular organelles fraction. EDTA addition alone increased the proportion of Pb in soluble and cellular organelles fraction, while DA-6 detoxified Pb in plant by storing additional Pb in cell wall, and 10μM DA-6 was the most effective. Of the total Pb in plant shoot, 27-52% was NaCl extractable, 22-47% HAc extractable, followed by other fractions. Contrary to EDTA, DA-6 significantly decreased Pb migration in plant. These results suggest that Pb fixation by pectates and proteins in cell wall and compartmentalization by vacuole might be responsible for Pb detoxification in plant, and the combined use of EDTA and 10μM DA-6 appears to be optimal for improving the remediation efficiency of L. perenne for Pb contaminated soil.

  13. Dynamic and steady-state responses of inorganic nitrogen pools and NH(3) exchange in leaves of Lolium perenne and Bromus erectus to changes in root nitrogen supply.

    PubMed

    Mattsson, Marie; Schjoerring, Jan K

    2002-02-01

    Short- and long-term responses of inorganic N pools and plant-atmosphere NH(3) exchange to changes in external N supply were investigated in 11-week-old plants of two grass species, Lolium perenne and Bromus erectus, characteristic of N-rich and N-poor grassland ecosystems, respectively. A switch of root N source from NO(-)(3)to NH(4)(+) caused within 3 h a 3- to 6-fold increase in leaf apoplastic NH(4)(+) concentration and a simultaneous decrease in apoplastic pH of about 0.4 pH units in both species. The concentration of total extractable leaf tissue NH(4)(+) also increased two to three times within 3 h after the switch. Removal of exogenous NH(4)(+) caused the apoplastic NH(4)(+) concentration to decline back to the original level within 24 h, whereas the leaf tissue NH(4)(+)concentration decreased more slowly and did not reach the original level in 48 h. After growing for 5 weeks with a steady-state supply of NO(-)(3)or NH(4)(+), L. perenne were in all cases larger, contained more N, and utilized the absorbed N more efficiently for growth than B. erectus, whereas the two species behaved oppositely with respect to tissue concentrations of NO(-)(3), NH(4)(+), and total N. Ammonia compensation points were higher for B. erectus than for L. perenne and were in both species higher for NH(4)(+)- than for NO(-)(3)-grown plants. Steady-state levels of apoplastic NH(4)(+), tissue NH(4)(+), and NH(3) emission were significantly correlated. It is concluded that leaf apoplastic NH(4)(+) is a highly dynamic pool, closely reflecting changes in the external N supply. This rapid response may constitute a signaling system coordinating leaf N metabolism with the actual N uptake by the roots and the external N availability.

  14. Does gibberellin biosynthesis play a critical role in the growth of Lolium perenne? Evidence from a transcriptional analysis of gibberellin and carbohydrate metabolic genes after defoliation

    PubMed Central

    Liu, Qianhe; Jones, Chris S.; Parsons, Anthony J.; Xue, Hong; Rasmussen, Susanne

    2015-01-01

    Global meat and milk production depends to a large extent on grazed pastures, with Lolium perenne being the major forage grass in temperate regions. Defoliation and subsequent regrowth of leaf blades is a major and essential event with respect to L. perenne growth and productivity. Following defoliation, carbohydrates (mainly fructans and sucrose) have to be mobilized from heterotrophic tissues to provide energy and carbon for regrowth of photosynthetic tissues. This mobilization of reserve carbohydrates requires a substantial change in the expression of genes coding for enzymes involved in carbohydrate metabolism. Here we tested the hypothesis that gibberellins (GA) are at the core of the processes regulating the expression of these genes. Thus, we examined the transcript profiles of genes involved in carbohydrate and GA metabolic pathways across a time course regrowth experiment. Our results show that following defoliation, the immediate reduction of carbohydrate concentrations in growing tissues is associated with a concomitant increase in the expression of genes encoding carbohydrate mobilizing invertases, and was also associated with a strong decrease in the expression of fructan synthesizing fructosyltransferase genes. We also show that the decrease in fructan levels is preceded by increased expression of the GA activating gene GA3-oxidase and decreased expression of the GA inactivating gene GA2-oxidase in sheaths. GA3-oxidase expression was negatively, while GA2-oxidase positively linked to sucrose concentrations. This study provides indicative evidence that gibberellins might play a role in L. perenne regrowth following defoliation and we hypothesize that there is a link between gibberellin regulation and sugar metabolism in L. perenne. PMID:26579182

  15. Biosafety testing of genetically modified ryegrass (Lolium perenne) using a model for the optimum selection of test invertebrates.

    PubMed

    Barratt, B I P; Todd, J H; Ferguson, C M; Crook, K; Burgess, E P J; Barraclough, E I; Malone, L A

    2013-08-01

    Selection of test species for use in biosafety evaluation of genetically modified plants is challenging but important, as regulators in many jurisdictions require tests to determine the potential for adverse environmental impacts before the release of plants into the environment. This contribution provides an example of an evidence-based process whereby species from the receiving environment can be ranked in order of susceptibility to potential impact, and guide test species selection. The case study used for this example was ryegrass, a forage plant, which had been modified to produce elevated levels of the lipid triacylglyceride. The previously described priority ranking of nontarget invertebrates model (PRONTI), designed to rank invertebrates for biosafety testing, has been adapted for use with these plants, which could, potentially, be beneficial to invertebrate populations, and applied to data on 246 known pasture invertebrate species. The output from the model for the top 20 ranked pasture invertebrate species is discussed, the attributes of these are considered along with the level of uncertainty in the information used. Consideration is given to how the model output can be interpreted and used in a biosafety risk assessment. While some subjectivity is involved in establishing the scores, all invertebrate species are subjected to the same analysis, and treated equally. In this way, regulators have a method of a risk assessment that is evidence-based, and transparent in its assumptions thereby avoiding potential for bias.

  16. Population Structure, Genetic Variation, and Linkage Disequilibrium in Perennial Ryegrass Populations Divergently Selected for Freezing Tolerance

    PubMed Central

    Kovi, Mallikarjuna Rao; Fjellheim, Siri; Sandve, Simen R.; Larsen, Arild; Rudi, Heidi; Asp, Torben; Kent, Matthew Peter; Rognli, Odd Arne

    2015-01-01

    Low temperature is one of the abiotic stresses seriously affecting the growth of perennial ryegrass (Lolium perenne L.), and freezing tolerance is a complex trait of major agronomical importance in northern and central Europe. Understanding the genetic control of freezing tolerance would aid in the development of cultivars of perennial ryegrass with improved adaptation to frost. The plant material investigated in this study was an experimental synthetic population derived from pair-crosses among five European perennial ryegrass genotypes, representing adaptations to a range of climatic conditions across Europe. A total number of 80 individuals (24 of High frost [HF]; 29 of Low frost [LF], and 27 of Unselected [US]) from the second generation of the two divergently selected populations and an unselected (US) control population were genotyped using 278 genome-wide SNPs derived from perennial ryegrass transcriptome sequences. Our studies investigated the genetic diversity among the three experimental populations by analysis of molecular variance and population structure, and determined that the HF and LF populations are very divergent after selection for freezing tolerance, whereas the HF and US populations are more similar. Linkage disequilibrium (LD) decay varied across the seven chromosomes and the conspicuous pattern of LD between the HF and LF population confirmed their divergence in freezing tolerance. Furthermore, two Fst outlier methods; finite island model (fdist) by LOSITAN and hierarchical structure model using ARLEQUIN, both detected six loci under directional selection. These outlier loci are most probably linked to genes involved in freezing tolerance, cold adaptation, and abiotic stress. These six candidate loci under directional selection for freezing tolerance might be potential marker resources for breeding perennial ryegrass cultivars with improved freezing tolerance. PMID:26617611

  17. Transcript profiling of fructan biosynthetic pathway genes reveals association of a specific fructosyltransferase isoform with the high sugar trait in Lolium perenne.

    PubMed

    Rasmussen, Susanne; Parsons, Anthony J; Xue, Hong; Liu, Qianhe; Jones, Christopher S; Ryan, Geraldine D; Newman, Jonathan A

    2014-04-15

    Lolium perenne cultivars with elevated levels of fructans in leaf blades (high sugar-content grasses) have been developed to improve animal nutrition and reduce adverse environmental impacts of pastoral agricultural systems. Expression of the high sugar trait can vary substantially depending on genotype×environment (G×E) interactions. We grew three potential high sugar-content and a control cultivar in three temperature regimes and quantified water soluble carbohydrates (WSCs) and the expression of all functionally characterised L. perenne fructan pathway genes in leaf tissues. We also analysed the distribution, expression and sequence variation of two specific isoforms of Lp6G-FFT (fructan: fructan 6G-fructosyltransferase). Our study confirmed a significant G×E interaction affecting the accumulation of fructans in the high sugar-content cultivar AberDart, which accumulated higher levels of high DP (degree of polymerisation) fructans in blades compared to the control cultivar only when grown at 20°C (day)/10°C (night) temperatures. The cultivar Expo on the other hand accumulated significantly higher levels of high DP fructans in blades independent of temperature. Fructan levels in pseudostems were higher than in blades, and they increased markedly with decreasing temperature, but there was no consistent effect of cultivar in this tissue. The expression of the high sugar trait was generally positively correlated with transcript levels of fructosyltransferases. Presence and expression of only one of the two known 6G-FFT isoforms was positively correlated with high fructan biosynthesis, while the second isoform was associated with low fructan concentrations and positively correlated with fructan exohydrolase gene expression. The presence of distinct 6G-FFT sequence variants appears to be associated with the capacity of high sugar-content grasses to accumulate higher fructan levels particularly at warmer temperatures. These findings might be exploited for the

  18. Effects of elevated ultraviolet radiation and endophytic fungi on plant growth and insect feeding in Lolium perenne, Festuca rubra, F. arundinacea and F. pratensis.

    PubMed

    McLeod, A R; Rey, A; Newsham, K K; Lewis, G C; Wolferstam, P

    2001-09-01

    Plants of perennial ryegrass (Lolium perenne L.), red fescue (Festuca rubra L.), tall fescue (F. arundinacea Schreb.) and meadow fescue (F. pratensis Huds) were exposed at an outdoor facility located in Edinburgh, UK to modulated levels of UV-B radiation (280-315 nm) using banks of cellulose diacetate filtered UV-B fluorescent lamps that also produce UV-A radiation (315-400 nm). The plants were derived from a single clone of each species and were grown both with and without colonization by naturally-occurring fungal endophytes. The UV-B treatment was a 30% elevation above the ambient erythemally-weighted level of UV-B during July to October. Growth of treated plants was compared with plants grown under elevated UV-A radiation alone produced by banks of polyester filtered lamps and with plants grown at ambient levels of solar radiation under banks of unenergized lamps. At the end of the treatment period, sample leaves were collected for feeding trials with the desert locust Schistocerca gregaria (Forsk). The UV-B treatment produced no effects on the aboveground biomass of any of the four grasses. The UV-B treatment and the UV-A control exposure both increased plant height and the number of daughter plants formed by rhizome growth in F. rubra. There were significant effects of endophyte presence on the total fresh and dry weights of F. arundinacea and F. rubra, on fresh weight only in F. pratensis, and on the fresh and dry weights of inflorescence in F. arundinacea and L. perenne. There were no effects of UV treatments on the absolute amounts of leaf consumed or on the feeding preferences of locusts for leaves with or without endophyte in three species: F. rubra, F. arundinacea and L. perenne. In F. pratensis there was no effect of UV treatment on the weight of leaves consumed but a significant UV x endophyte interaction caused by a marked change in feeding preference between leaves with and without endophyte that differed between the UV-B treatment and UV-A control

  19. Pathological changes seen in horses in New Zealand grazing Mediterranean tall fescue (Lolium arundinaceum) infected with selected endophytes (Epichloë coenophiala) causing equine fescue oedema.

    PubMed

    Munday, J S; Finch, S C; Vlaming, J B; Sutherland, B L; Fletcher, L R

    2017-05-01

    To investigate whether Mediterranean tall fescue (Lolium arundinaceum (Schreb.) Darbysh. (syn Festuca arundinacea)) infected with selected fungal endophytes (Epichloë coenophiala (formerly Neotyphodium coenophialum)) caused equine fescue oedema when grown in New Zealand, and to examine the pathological changes associated with this intoxication. Horses were grazed on Mediterranean tall fescue that was infected with the endophytes AR542 (n=2), or AR584 (n=3), or Mediterranean tall fescue that was endophyte-free (n=2). Blood samples were taken up to 7 days after the start of feeding to detect changes in concentrations of total protein in serum and packed cell volume. Any horse showing clinical evidence of disease was subject to euthanasia and necropsy. Within 6 days, both horses grazing fescue infected with AR542 became depressed and lethargic. One horse grazing fescue infected with endophyte AR584 became depressed within a 5-day feeding period while another horse in this group died shortly after being removed from the AR584 pasture. The third horse in this group did not develop clinical signs within the 5-day feeding period. However, haemoconcentration and hypoproteinaemia was detected in all horses grazing Mediterranean tall fescue that was infected by AR542 or AR584 endophyte. No abnormalities were observed in horses grazing fescue that was endophyte-free. Necropsy examination was performed on two horses grazing fescue infected with AR542 and one horse grazing fescue infected with AR584. All three horses had marked oedema of the gastrointestinal tract. Histologically, the oedema was accompanied by large numbers of eosinophils, but no necrosis. Horses grazing Mediterranean tall fescue that was infected by AR542 or AR584 developed hypoproteinaemia and haemoconcentration, most likely due to leakage of plasma proteins into the gastrointestinal tract. This suggests that these selected endophytes produce a compound that is toxic to horses, although the toxic principle

  20. Further investigation of equine fescue oedema induced by Mediterranean tall fescue (Lolium arundinaceum) infected with selected fungal endophytes (Epichloë coenophiala).

    PubMed

    Finch, S C; Munday, J S; Sutherland, B L; Vlaming, J B; Fletcher, L R

    2017-11-01

    AIMS To determine if equine fescue oedema (EFO) induced by grazing Mediterranean-type tall fescue (Lolium arundinaceum) infected with selected endophytes (Epichloë coenophiala) could be prevented by treatment with the corticosteroid, methylprednisolone, and anti-histamine, cetirizine, and to determine concentrations of lolines, specifically N-acetyl norloline (NANL), in grasses grazed by horses that did and did not develop EFO. METHODS Four horses were grazed on AR542-infected Mediterranean tall fescue pasture (from Day 0) for 7 days prior to being subjected to euthanasia. Two of these horses were treated with 250 mg methylprednisolone and 300 mg cetirizine hydrochloride every 12 hours orally from Days 0-7. Two more horses grazed meadow fescue (Festuca pratensis) infected with the naturally-occurring, common endophyte (Epichloë uncinata) for 21 days before euthanasia. All horses were observed closely for signs of EFO, and blood samples were taken daily for measurement of concentrations of total protein (TP) in serum. Following euthanasia post-mortem examinations were conducted on all horses. Pasture samples of meadow fescue and Mediterranean tall fescue from the current study, and endophyte-infected Mediterranean tall fescue from a previous study that were associated with EFO, were analysed for concentrations of lolines using gas chromatography. RESULTS By Day 7, the treated and untreated horses grazing AR542-infected Mediterranean tall fescue all developed signs of EFO, and concentrations of TP in serum of all horses were <45 g/L. No signs of EFO were observed in horses grazing meadow fescue and concentrations of TP remained above 60 g/L. Necropsy showed marked oedema and eosinophilic inflammation in the intestines of all horses grazing Mediterranean tall fescue. In the sample of meadow fescue, concentrations of total lolines and N-acetyl norloline (NANL) were 2,402 and 543 mg/kg, respectively. In the three samples of Mediterranean tall fescue

  1. The photosynthetic acclimation of Lolium perenne in response to three years growth in a free-air CO2 enrichment (FACE) system

    SciTech Connect

    Hymus, Graham J.

    1996-08-01

    Pure stands of Ryegrass were in their third year of growth in the field, exposed to either ambient (355 μmol mol-1), or elevated (600 μmol mol-1) atmospheric CO2 concentration. A Free-Air CO2 Enrichment (FACE) system was used to maintain the elevated CO2 concentration whilst limiting experimental constraints on the field conditions. The theoretically predicted increase in the net rates of CO2 uptake per unit leaf area (A {mu}mol mol-1) as a consequence, primarily, of the suppression of photorespiration by CO2 a competitive inhibitor of RubP oxygenation by Rubisco, was observed for the Lolium perenne studied. Also observed was a general decline in leaf evapotranspiration (E) consistent with observations of increased water use efficiency of crops grown in elevated CO2. Enhancement of leaf A in the FACE grown L. perenne ranged from 26.5 1 % to 44.95% over the course of a diurnal set of measurements. Whilst reductions in leaf E reached a maximum of 16.61% over the same diurnal course of-measurements. The increase in A was reconciled with an absence of the commonly observed decline in Vcmax as a measure of the maximum in vivo carboxylation capacity of the primary carboxylasing enzyme Rubisco and Jmax a measure of the maximum rate of electron transport. The manipulation of the source sink balance of the crop, stage of canopy regrowth or height in the canopy had no effect on the observation of a lack of response. The findings of this study will be interpreted with respect to the long term implications of C3 crops being able to adapt physiologically to maximize the potential benefits conferred by growth in elevated CO2.

  2. A review of the Neotyphodium lolii / Lolium perenne symbiosis and its associated effects on animal and plant health, with particular emphasis on ryegrass staggers.

    PubMed

    di Menna, M E; Finch, S C; Popay, A J; Smith, B L

    2012-11-01

    Ryegrass staggers is a seasonal mycotoxicosis of grazing livestock characterised by tremors, in coordination and a staggering gait almost unaccompanied by physical lesions. Deaths occur only as a consequence of accident or starvation. Outbreaks, in summer and autumn, occur only on pasture in which endophyte (Neotyphodium lolii)-infected perennial ryegrass (Lolium perenne) predominates and usually on which animals are grazed intensively. Animals recover when moved to a different type of grazing or after rain has promoted pasture growth. The disease was recognised for 80 years before its cause was discovered as a consequence of a grazing trial of sheep on three ryegrass cultivars which happened to have three different levels of endophyte infection. The endophyte was first formally described as Acremonium loliae, later corrected to Acremonium lolii, and was finally placed in the genus Neotyphodium. It produces a number of secondary metabolites of which lolitrem B is the principal one causing ryegrass staggers symptoms. Ergopeptides are also produced which cause heat stress and lack of productivity. N. lolii is symptomless in the plant, seed borne and grows intercellularly in the aerial parts, mainly in reproductive tillers and leaf sheaths but sparsely in leaf blades. It dies in stored seed and infection rates of different ryegrass cultivars have depended on seed storage times during their production. In addition, N. Lolii produces insect feeding deterrents, among them peramine, which protects infected plants from pest predation. Because of this, control of ryegrass staggers by elimination of endophyte-infected ryegrass is not feasible in areas in which insect predation is a serious pasture problem. However, N. lolii strains vary in the secondary metabolites they produce allowing the selection of strains that produce desirable metabolites. By inoculating such strains into uninfected ryegrass plants it is possible to produce cultivars which do not cause ryegrass

  3. Frequency, type, and distribution of EST-SSRs from three genotypes of Lolium perenne, and their conservation across orthologous sequences of Festuca arundinacea, Brachypodium distachyon, and Oryza sativa

    PubMed Central

    Asp, Torben; Frei, Ursula K; Didion, Thomas; Nielsen, Klaus K; Lübberstedt, Thomas

    2007-01-01

    Background Simple sequence repeat (SSR) markers are highly informative and widely used for genetic and breeding studies in several plant species. They are used for cultivar identification, variety protection, as anchor markers in genetic mapping, and in marker-assisted breeding. Currently, a limited number of SSR markers are publicly available for perennial ryegrass (Lolium perenne). We report on the exploitation of a comprehensive EST collection in L. perenne for SSR identification. The objectives of this study were 1) to analyse the frequency, type, and distribution of SSR motifs in ESTs derived from three genotypes of L. perenne, 2) to perform a comparative analysis of SSR motif polymorphisms between allelic sequences, 3) to conduct a comparative analysis of SSR motif polymorphisms between orthologous sequences of L. perenne, Festuca arundinacea, Brachypodium distachyon, and O. sativa, 4) to identify functionally associated EST-SSR markers for application in comparative genomics and breeding. Results From 25,744 ESTs, representing 8.53 megabases of nucleotide information from three genotypes of L. perenne, 1,458 ESTs (5.7%) contained one or more SSRs. Of these SSRs, 955 (3.7%) were non-redundant. Tri-nucleotide repeats were the most abundant type of repeats followed by di- and tetra-nucleotide repeats. The EST-SSRs from the three genotypes were analysed for allelic- and/or genotypic SSR motif polymorphisms. Most of the SSR motifs (97.7%) showed no polymorphisms, whereas 22 EST-SSRs showed allelic- and/or genotypic polymorphisms. All polymorphisms identified were changes in the number of repeat units. Comparative analysis of the L. perenne EST-SSRs with sequences of Festuca arundinacea, Brachypodium distachyon, and Oryza sativa identified 19 clusters of orthologous sequences between these four species. Analysis of the clusters showed that the SSR motif generally is conserved in the closely related species F. arundinacea, but often differs in length of the SSR

  4. Nitrous oxide emission factors for urine and dung from sheep fed either fresh forage rape (Brassica napus L.) or fresh perennial ryegrass (Lolium perenne L.).

    PubMed

    Luo, J; Sun, X Z; Pacheco, D; Ledgard, S F; Lindsey, S B; Hoogendoorn, C J; Wise, B; Watkins, N L

    2015-03-01

    In New Zealand, agriculture is predominantly based on pastoral grazing systems and animal excreta deposited on soil during grazing have been identified as a major source of nitrous oxide (N2O) emissions. Forage brassicas (Brassica spp.) have been increasingly used to improve lamb performance. Compared with conventional forage perennial ryegrass (Lolium perenne L.), a common forage in New Zealand, forage brassicas have faster growth rates, higher dry matter production and higher nutritive value. The aim of this study was to determine the partitioning of dietary nitrogen (N) between urine and dung in the excreta from sheep fed forage brassica rape (B. napus subsp. oleifera L.) or ryegrass, and then to measure N2O emissions when the excreta from the two different feed sources were applied to a pasture soil. A sheep metabolism study was conducted to determine urine and dung-N outputs from sheep fed forage rape or ryegrass, and N partitioning between urine and dung. Urine and dung were collected and then used in a field plot experiment for measuring N2O emissions. The experimental site contained a perennial ryegrass/white clover pasture on a poorly drained silt-loam soil. The treatments included urine from sheep fed forage rape or ryegrass, dung from sheep fed forage rape or ryegrass, and a control without dung or urine applied. N2O emission measurements were carried out using a static chamber technique. For each excreta type, the total N2O emissions and emission factor (EF3; N2O-N emitted during the 3- or 8-month measurement period as a per cent of animal urine or dung-N applied, respectively) were calculated. Our results indicate that, in terms of per unit of N intake, a similar amount of N was excreted in urine from sheep fed either forage rape or ryegrass, but less dung N was excreted from sheep fed forage rape than ryegrass. The EF3 for urine from sheep fed forage rape was lower compared with urine from sheep fed ryegrass. This may have been because of plant

  5. Nutrient Availability and Atmospheric CO2 Partial Pressure Modulate the Effects of Nutrient Heterogeneity on the Size Structure of Populations in Grassland Species

    PubMed Central

    MAESTRE, FERNANDO T.; REYNOLDS, JAMES F.

    2006-01-01

    • Background and Aims Size-asymmetric competition occurs when larger plants have a disproportionate advantage in competition with smaller plants. It has been hypothesized that nutrient heterogeneity may promote it. Experiments testing this hypothesis are inconclusive, and in most cases have evaluated the effects of nutrient heterogeneity separately from other environmental factors. The aim of this study was to test, using populations of Lolium perenne, Plantago lanceolata and Holcus lanatus, two hypotheses: (a) nutrient heterogeneity promotes size-asymmetric competition; and (b) nutrient heterogeneity interacts with both atmospheric CO2 partial pressure (PCO2) and nutrient availability to determine the magnitude of this response. • Methods Microcosms consisting of monocultures of the three species were grown for 90 d in a factorial experiment with the following treatments: PCO2 (37·5 and 70 Pa) and nutrient availability (NA; 40 and 120  mg of N added as organic material) combined with different spatial distribution of the organic material (NH; homogeneous and heterogeneous). Differences in the size of individual plants within populations (size inequality) were quantified using the coefficient of variation of individual above-ground biomass and the combined biomass of the two largest individuals in each microcosm. Increases in size inequality were associated with size-asymmetric competition. • Key Results Size inequality increased when the nutrients were heterogeneously supplied in the three species. The effects of NH on this response were more pronounced under high nutrient supply in both Plantago and Holcus (significant NA × NH interactions) and under elevated PCO2 in Plantago (significant PCO2 × NA × NH interaction). No significant two- and three-way interactions were found for Lolium. • Conclusions Our first hypothesis was supported by our results, as nutrient heterogeneity promoted size-asymmetric competition in the three species evaluated

  6. The Effect of Marigolds (Tagetes spp.) and Other Cover Crops on Pratylenchus penetrans and on Following Potato Crops.

    PubMed

    Kimpinski, J; Arsenault, W J; Gallant, C E; Sanderson, J B

    2000-12-01

    Root-lesion nematodes (primarily Pratylenchus penetrans) were monitored in two marigold cultivars (Tagetes tenuifolia cv. Nemakill and cv. Nemanon), annual ryegrass (Lolium multiflorum cv. Lemtal), red clover (Trifolium pratense cv. Florex), and soybean (Glycine max cv. Proteus), and in the following potato (Solanum tuberosum cv. Superior) crop during three growth sequences. Meadow fescue (Festuca elatior cv. Miner) and bee plant (Phacelia tanacetifolia cv. Gipha) were added to the trial in the second year. Black-eyed Susan (Rudbeckia hirta, unidentified cv.) and two additional marigold cultivars (T. patula ssp. nana, unidentified cv., and T. erecta cv. Crackerjack) were included in the final sequence. Population levels of root-lesion nematodes were consistently lower under marigolds compared to the other cover crops tested. Correspondingly, average potato tuber yields were significantly higher (8-14%) when potato followed marigolds. The highest levels of root-lesion nematodes occurred under red clover and soybean, and the average potato tuber yields were lowest following these crops.

  7. Spring nitrogen fertilization of ryegrass-bermudagrass for phytoremediation of phosphorus-enriched soils

    USDA-ARS?s Scientific Manuscript database

    Nitrogen fertilization of forage grasses is critical for optimizing biomass and utilization of manure soil nutrients. Field studies were conducted in 2007-09 to determine the effects of spring N fertilization on amelioration of high soil P when cool-season, annual ryegrass (Lolium multiflorum L.) is...

  8. Phytoremediation of high phosphorus soil by annual ryegrass and common bermudagrass harvest

    USDA-ARS?s Scientific Manuscript database

    Removal of soil phosphorus (P) in crop harvest is a remediation option for soils high in P. This four-year field-plot study determined P uptake by annual ryegrass (ARG, Lolium multiflorum Lam.) and common bermudagrass (CB, Cynodon dactylon (L.) Pers.) from Ruston soil (fine-loamy, siliceous, thermic...

  9. Wildfire, ryegrass seeding, and watershed rehabilitation

    Treesearch

    R. D. Taskey; C. L. Curtis; J. Stone

    1989-01-01

    Aerial seeding of Italian annual ryegrass (Lolium multiflorum) is a common, but controversial, emergency rehabilitation practice following wildfire in California. Replicated study plots, with and without ryegrass, established after a summertime chaparral wildfire on California's central coast revealed the following: 1. Ryegrass-seeded plots...

  10. Effects of post-fire grass seeding on native vegetation in southern California chaparral

    Treesearch

    Jan L. Beyers; Carla D. Wakeman; Peter M. Wohlgemuth; Susan G. Conard

    1998-01-01

    For decades, managers have seeded burned slopes with annual grass in an attempt to increase postfire plant cover and reduce the accelerated hillslope erosion, runoff, and debris flows that typically occur during the first winter after fire. In California, annual ryegrass (Lolium multiflorum) was commonly used for this purpose. Critics argue that ryegrass and other...

  11. Morphological traits associated with weed-suppressive ability of winter wheat against Italian ryegrass

    USDA-ARS?s Scientific Manuscript database

    Weed-suppressive wheat (Triticum aestivum L.) cultivars have been suggested as a complement to chemical and cultural methods of weed control. The objectives of this study were to assess the range of weed-suppressive ability against Italian ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] ...

  12. Predation of warm-and cool-season grass seed by the common cricket (Acheta domesticus L.)

    USDA-ARS?s Scientific Manuscript database

    In field experiments we noted that one of the main predators of tall fescue (Festuca arundinacea Schreb.) and Italian ryegrass (Lolium multiflorum Lam.) seed was the field cricket (Gryllus sp.). To determine if there might be a seed predation preference among forage grasses a laboratory study was ...

  13. Impacts of postfire grass seeding on vegetation recovery in southern California chaparral

    Treesearch

    Jan Beyers; C.D. Wakeman; S.G. Conard; Pete Wohlgemuth

    2002-01-01

    Postfire grass seeding as an attempt at erosion control on chaparral slopes has been a common practice for decades. Annual ryegrass (Lolium multiflorum) has been most frequently used. Critics point out that ryegrass can suppress native species and may reduce shrub seedling survival. In 1986, we began investigating the impacts of seeded ryegrass on chaparral...

  14. Effects of Wastewater and Sewage Sludge on the Growth and Chemical Composition of Turfgrass.

    DTIC Science & Technology

    1978-11-01

    of Kentucky bluegrass (Poa pratensis L. var. ’Merion’), red fescue ( Festuca rubra L. var. ’Pennlawn’) and annual ryegrass. The mixtures were grown in...turfgrass mixtures. A mixture of tall fescue ( Festuca arundinacea Scheb var. ’K-31’) and annual ryegrass (Lolium multiflorum Lam.) was compared to a mixture

  15. Differential predation of forage seed

    USDA-ARS?s Scientific Manuscript database

    In recent field experiments we observed that the main invertebrate seed predators of overseeded tall fescue (Festuca arundinacea Schreb.) or Italian ryegrass (Lolium multiflorum Lam.) seed in unimproved pastures were harvester ants (Pogonomyrmex sp.) and common field crickets (Gryllus sp.) To determ...

  16. First report of Fusarium graminearum, F. asiaticum and F. cortaderiae as head blight pathogens of annual ryegrass in Brazil

    USDA-ARS?s Scientific Manuscript database

    Members of the Fusarium graminearum species complex (FGSC) cause Fusarium head blight (FHB) of small grains and several grasses, including annual ryegrass (Lolium multiflorum Lam.), an important forage crop, but also a common weed in wheat, rice and maize agroecosystem in southern Brazil. Although i...

  17. Performance by heifers grazing sod-seeded cool-season annuals seeded on different dates using two tillage intensities

    USDA-ARS?s Scientific Manuscript database

    A total of 120 Gelbvieh x Angus crossbred heifers (552'2.5 lb initial BW) grazed pastures of common bermudagrass [Cynodon dactylon (L.) Pers.] overseeded with wheat (Triticum aestivum L.) and annual ryegrass (Lolium multiflorum Lam.) for a 3-year study to compare the effect of seeding dates and till...

  18. Tillage requirements for vegetables following winter annual grazing

    USDA-ARS?s Scientific Manuscript database

    In Alabama, over 400,000 ac of winter annuals are grazed prior to planting summer row crops. Previous research indicates that cattle grazed on ryegrass (Lolium multiflorum L.) pastures over the winter months in Alabama can be profitable, but winter grazing creates excessive compaction, which advers...

  19. Report of Glyceria declinata in Oregon

    USDA-ARS?s Scientific Manuscript database

    During official regulatory testing of grass seed shipments bound for Australia, seeds of a Glyceria species were detected in shipments of annual ryegrass (Lolium multiflorum Lam.). According to existing scientific literature, seven of the 18 Glyceria species known to occur in North America are foun...

  20. Hairy chinch bug (Hemiptera: Lygaeidae) damage, population density, and movement in relation to the incidence of perennial ryegrass infected by Neotyphodium endophytes.

    PubMed

    Richmond, D S; Shetlar, D J

    2000-08-01

    Studies examined hairy chinch bug, Blissus leucopterus hirtus Montandon, damage, population density, and movement in stands of perennial ryegrass, Lolium perenne L., containing various proportions of endophyte infected plants (E+). Our main objective was to determine the utility of mixtures containing E+ for management of chinch bugs. Chinch bug damage and population density decreased linearly as the proportion of E+ increased. This trend held true even when chinch bug populations were extremely high. Chinch bug nymphs emigrated more quickly from stands containing 100% E+ than they did from stands containing 50 or 0% E+, whereas adult chinch bug emigration was relatively unaffected by the proportion of E+. Our results indicate that turfgrass mixtures containing E+ can reduce chinch bug damage and population density.

  1. T cell epitopes of the major fraction of rye grass Lolium perenne (Lol p I) defined using overlapping peptides in vitro and in vivo. I. Isoallergen clone1A.

    PubMed Central

    Bungy Poor Fard, G A; Latchman, Y; Rodda, S; Geysen, M; Roitt, I; Brostoff, J

    1993-01-01

    One hundred and fifteen overlapping synthetic peptides spanning the entire sequence of the iso-allergen clone1A of Lol p I from rye grass Lolium perenne were synthesized by the multi-pin technique. The peptides were overlapping 12mers, offset by two residues and overlapping by 10 residues. Sets of six adjacent overlapping peptides (except pool-1, 15, 20) were pooled and were used in vitro and in vivo to map the T cell epitopes on Lol p I. Six atopics who were skin test and RAST positive to rye grass showed T cell responses to L. perenne extract (LPE) and its major fraction (Lol p I). Five out of six showed T cell responses in vitro to peptide pool-17, while five non-atopics did not respond to any of the peptide pools. By testing the individual peptides of pool-17, we have located the T cell epitope on Lol p I. Interestingly, when we tested pool-17 and its single peptides in vivo by intradermal skin testing we found in one patient a typical DTH after 24-48 h to pool-17 and its peptides (peptides 3 and 4) which exactly matched the in vitro responses. By defining the T cell epitopes in this way a greater understanding of the allergic response to pollen will be obtained, and a more effective and less dangerous vaccine may be possible for treating patients with hay fever. PMID:7691451

  2. T cell epitopes of the major fraction of rye grass Lolium perenne (Lol p I) defined using overlapping peptides in vitro and in vivo. I. Isoallergen clone1A.

    PubMed

    Bungy Poor Fard, G A; Latchman, Y; Rodda, S; Geysen, M; Roitt, I; Brostoff, J

    1993-10-01

    One hundred and fifteen overlapping synthetic peptides spanning the entire sequence of the iso-allergen clone1A of Lol p I from rye grass Lolium perenne were synthesized by the multi-pin technique. The peptides were overlapping 12mers, offset by two residues and overlapping by 10 residues. Sets of six adjacent overlapping peptides (except pool-1, 15, 20) were pooled and were used in vitro and in vivo to map the T cell epitopes on Lol p I. Six atopics who were skin test and RAST positive to rye grass showed T cell responses to L. perenne extract (LPE) and its major fraction (Lol p I). Five out of six showed T cell responses in vitro to peptide pool-17, while five non-atopics did not respond to any of the peptide pools. By testing the individual peptides of pool-17, we have located the T cell epitope on Lol p I. Interestingly, when we tested pool-17 and its single peptides in vivo by intradermal skin testing we found in one patient a typical DTH after 24-48 h to pool-17 and its peptides (peptides 3 and 4) which exactly matched the in vitro responses. By defining the T cell epitopes in this way a greater understanding of the allergic response to pollen will be obtained, and a more effective and less dangerous vaccine may be possible for treating patients with hay fever.

  3. SymB and SymC, two membrane associated proteins, are required for Epichloë festucae hyphal cell-cell fusion and maintenance of a mutualistic interaction with Lolium perenne.

    PubMed

    Green, Kimberly A; Becker, Yvonne; Tanaka, Aiko; Takemoto, Daigo; Fitzsimons, Helen L; Seiler, Stephan; Lalucque, Hervé; Silar, Philippe; Scott, Barry

    2017-02-01

    Cell-cell fusion in fungi is required for colony formation, nutrient transfer and signal transduction. Disruption of genes required for hyphal fusion in Epichloë festucae, a mutualistic symbiont of Lolium grasses, severely disrupts the host interaction phenotype. They examined whether symB and symC, the E. festucae homologs of Podospora anserina self-signaling genes IDC2 and IDC3, are required for E. festucae hyphal fusion and host symbiosis. Deletion mutants of these genes were defective in hyphal cell fusion, formed intra-hyphal hyphae, and had enhanced conidiation. SymB-GFP and SymC-mRFP1 localize to plasma membrane, septa and points of hyphal cell fusion. Plants infected with ΔsymB and ΔsymC strains were severely stunted. Hyphae of the mutants colonized vascular bundles, were more abundant than wild type in the intercellular spaces and formed intra-hyphal hyphae. Although these phenotypes are identical to those previously observed for cell wall integrity MAP kinase mutants no difference was observed in the basal level of MpkA phosphorylation or its cellular localization in the mutant backgrounds. Both genes contain binding sites for the transcription factor ProA. Collectively these results show that SymB and SymC are key components of a conserved signaling network for E. festucae to maintain a mutualistic symbiotic interaction within L. perenne. © 2016 The Authors. Molecular Microbiology Published by John Wiley & Sons Ltd.

  4. Arbuscular mycorrhizal fungi enhance both absorption and stabilization of Cd by Alfred stonecrop (Sedum alfredii Hance) and perennial ryegrass (Lolium perenne L.) in a Cd-contaminated acidic soil.

    PubMed

    Hu, Junli; Wu, Shengchun; Wu, Fuyong; Leung, Ho Man; Lin, Xiangui; Wong, Ming Hung

    2013-10-01

    A greenhouse pot experiment was conducted to compare the phytoextraction efficiencies of Cd by hyper-accumulating Alfred stonecrop (Sedum alfredii Hance) and fast-growing perennial ryegrass (Lolium perenne L.) from a Cd-contaminated (1.6 mg kg(-1)) acidic soil, and their responses to the inoculations of two arbuscular mycorrhizal (AM) fungal strains, Glomus caledonium 90036 (Gc) and Glomus mosseae M47V (Gm). Ryegrass and stonecrop were harvested after growing for 9 and 27 wk, respectively. Without AM fungal inoculation, the weekly Cd extraction by stonecrop (8.0 μg pot(-1)) was 4.3 times higher than that by ryegrass (1.5 μg pot(-1)). Both Gc and Gm significantly increased (P < 0.05) root mycorrhizal colonization rates, soil acid phosphatase activities, and available P concentrations, and thereby plant P absorptions (except for Gm-inoculated ryegrass), shoot biomasses, and Cd absorptions (except for Gm-inoculated stonecrop), while only Gc-inoculated stonecrop significantly accelerated (P < 0.05) the phytoextraction efficiency of Cd by 78%. In addition, both Gc and Gm significantly decreased (P < 0.05) phytoavailable Cd concentrations by 21-38% via elevating soil pH. The results suggested the potential application of hyper-accumulating Alfred stonecrop associated with AM fungi (notably Gc) for both extraction and stabilization of Cd in the in situ treatment of Cd-contaminated acidic soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Mapping Drought QTL in Tall Fescue Populations

    USDA-ARS?s Scientific Manuscript database

    Tall fescue [Lolium arundinacetum (Schreb.) Darbysh.] growth and persistence are adversely affected by the hot-dry summers in the Southern Great Plains (Hopkins, 2005). Both forage yield and drought tolerance are difficult to select for because of large genotype-by-environment interactions. The ob...

  6. [Population statistics].

    PubMed

    1992-01-01

    Population trends in Luxembourg in 1991 are first reviewed, with separate consideration given to nuptiality and divorce, fertility, mortality, and migration. Next, revised estimates of international migration and of the resident population are presented for the period 1987-1991. Finally, three alternative estimates of the population for 1991 are provided.

  7. Understanding Population.

    ERIC Educational Resources Information Center

    Mothner, Ira

    Activities and concerns of Ford Foundation supported population research and training centers are described in this report. The centers are concerned with population growth, consequences of growth for human welfare, forces that determine family planning, interrelations among population variables, economics of contraceptive distribution, and…

  8. Counting Populations

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    Scientists use sampling to get an estimate of things they cannot easily count. A population is made up of all the organisms of one species living together in one place at the same time. All of the people living together in one town are considered a population. All of the grasshoppers living in a field are a population. Scientists keep track of the…

  9. Population Research.

    ERIC Educational Resources Information Center

    National Inst. of Child Health and Human Development (NIH), Bethesda, MD.

    The scope of population research as carried on by the National Institute of Child Health and Human Development (NICHD) is set forth in this booklet. Population problems of the world, United States, and the individual are considered along with international population policies based on voluntary family planning programs. NICHD goals for biological…

  10. Counting Populations

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    Scientists use sampling to get an estimate of things they cannot easily count. A population is made up of all the organisms of one species living together in one place at the same time. All of the people living together in one town are considered a population. All of the grasshoppers living in a field are a population. Scientists keep track of the…

  11. Stabilizing population.

    PubMed

    Brown, L; Mitchell, J

    1998-04-01

    This article is a reprint of the Worldwatch Institute's "State of the World Report," Chapter 10: "Building a New Economy." 16 countries reached zero population growth by 1997. 33 countries have stabilized population, which amounts to 14% of world population. It is estimated that by 2050 population will include an additional 3.6 billion people beyond the present 6 billion. About 60% of the added population will be in Asia, an increase from 3.4 billion in 1995 to 5.4 billion in 2050. China's current population of 1.2 billion will reach 1.5 billion. India's population is expected to rapidly rise from 930 million to 1.53 billion. Populations in the Middle East and North Africa are expected to double in size. Sub-Saharan population is expected to triple in size. By 2050, Nigeria will have 339 million people, which was the entire population of Africa in 1960. There is a great need to stabilize population in a number of currently unstabilized countries. In 1971, Bangladesh and Pakistan had the same population; however, by 2050, Pakistan, without a strong commitment to reducing population growth, will have 70 million more people than Bangladesh. Population stabilization will depend on removal of physical and social barriers that prevent women from using family planning services and thereby help them control their own unwanted fertility. Stabilization will require poverty alleviation and removal of the need for large families. Family size is reduced with lower infant and child mortality risk, increased education, a higher legal age of marriage, and investment in stabilization programs. Solutions to global population growth cannot wait for health reform and budget deficit reductions.

  12. Molecular and functional characterization of a cDNA encoding fructan:fructan 6G-fructosyltransferase (6G-FFT)/fructan:fructan 1-fructosyltransferase (1-FFT) from perennial ryegrass (Lolium perenne L.).

    PubMed

    Lasseur, Bertrand; Lothier, Jérémy; Djoumad, Abdelmadjid; De Coninck, Barbara; Smeekens, Sjef; Van Laere, André; Morvan-Bertrand, Annette; Van den Ende, Wim; Prud'homme, Marie-Pascale

    2006-01-01

    Fructans are the main storage compound in Lolium perenne. To account for the prevailing neokestose-based fructan synthesis in this species, a cDNA library of L. perenne was screened by using the onion (Allium cepa) fructan:fructan 6G-fructosyltransferase (6G-FFT) as a probe. A full length Lp6G-FFT clone was isolated with significant homologies to vacuolar type fructosyltransferases and invertases. The functionality of the cDNA was tested by heterologous expression in Pichia pastoris. The recombinant protein demonstrated both 6G-FFT and fructan:fructan 1-fructosyltransferase activities (1-FFT) with a maximum 6G-FFT/1-FFT ratio of two. The activity of 6G-FFT was investigated with respect to developmental stage, tissue distribution, and alterations in carbohydrate status expression and compared to sucrose:sucrose 1-fructosyltransferase (1-SST). Lp6G-FFT and Lp1-SST were predominantly expressed in the basal part of elongating leaves and leaf sheaths. Expression of both genes declined along the leaf axis, in parallel with the spatial occurrence of fructan and fructosyltransferase activities. Surprisingly, Lp6G-FFT was highly expressed in photosynthetically active tissues where very low extractable fructosyltransferase activity and fructan amounts were detected, suggesting a post-transcriptional regulation of expression. Lp6G-FFT gene expression increased only in elongating leaves following similar increases of sucrose content in blades, sheaths, and elongating leaf bases. Regulation of Lp6G-FFT gene expression depends on the tissue according to its sink-source status.

  13. Exogenous Melatonin Suppresses Dark-Induced Leaf Senescence by Activating the Superoxide Dismutase-Catalase Antioxidant Pathway and Down-Regulating Chlorophyll Degradation in Excised Leaves of Perennial Ryegrass (Lolium perenne L.)

    PubMed Central

    Zhang, Jing; Li, Huibin; Xu, Bin; Li, Jing; Huang, Bingru

    2016-01-01

    Leaf senescence is a typical symptom in plants exposed to dark and may be regulated by plant growth regulators. The objective of this study was to determine whether exogenous application of melatonin (N-acetyl-5-methoxytryptamine) suppresses dark-induced leaf senescence and the effects of melatonin on reactive oxygen species (ROS) scavenging system and chlorophyll degradation pathway in perennial grass species. Mature perennial ryegrass (Lolium perenne L. cv. ‘Pinnacle’) leaves were excised and incubated in 3 mM 2-(N-morpholino) ethanesulfonic buffer (pH 5.8) supplemented with melatonin or water (control) and exposed to dark treatment for 8 days. Leaves treated with melatonin maintained significantly higher endogenous melatonin level, chlorophyll content, photochemical efficiency, and cell membrane stability expressed by lower electrolyte leakage and malondialdehyde (MDA) content compared to the control. Exogenous melatonin treatment also reduced the transcript level of chlorophyll degradation-associated genes and senescence marker genes (LpSAG12.1, Lph36, and Lpl69) during the dark treatment. The endogenous O2- production rate and H2O2 content were significantly lower in these excised leaves treated with melatonin compared to the water control. Exogenous melatonin treatment caused increases in enzymatic activity and transcript levels of superoxide dismutase and catalase but had no significant effects on ascorbate peroxidase, glutathione reductase, dehydroascorbate reductase, and monohydroascorbate reductase. The content of non-enzymatic antioxidants, such as ascorbate and dehydroascorbate, were decreased by melatonin treatment, while the content of glutathione and oxidized glutathione was not affected by melatonin. These results suggest that the suppression of dark-induced leaf senescence by exogenous melatonin may be associated with its roles in regulating ROS scavenging through activating the superoxide dismutase-catalase enzymatic antioxidant pathway and

  14. Towards a better understanding of the generation of fructan structure diversity in plants: molecular and functional characterization of a sucrose:fructan 6-fructosyltransferase (6-SFT) cDNA from perennial ryegrass (Lolium perenne)

    PubMed Central

    Lasseur, Bertrand; Lothier, Jérémy; Wiemken, Andres; Van Laere, André; Morvan-Bertrand, Annette; den Ende, Wim Van; Prud'homme, Marie-Pascale

    2011-01-01

    The main storage compounds in Lolium perenne are fructans with prevailing β(2–6) linkages. A cDNA library of L. perenne was screened using Poa secunda sucrose:fructan 6-fructosyltransferase (6-SFT) as a probe. A full-length Lp6-SFT clone was isolated as shown by heterologous expression in Pichia pastoris. High levels of Lp6-SFT transcription were found in the growth zone of elongating leaves and in mature leaf sheaths where fructans are synthesized. Upon fructan synthesis induction, Lp6-SFT transcription was high in mature leaf blades but with no concomitant accumulation of fructans. In vitro studies with the recombinant Lp6-SFT protein showed that both 1-kestotriose and 6G-kestotriose acted as fructosyl acceptors, producing 1- and 6-kestotetraose (bifurcose) and 6G,6-kestotetraose, respectively. Interestingly, bifurcose formation ceased and 6G,6-kestotetraose was formed instead, when recombinant fructan:fructan 6G-fructosyltransferase (6G-FFT) of L. perenne was introduced in the enzyme assay with sucrose and 1-kestotriose as substrates. The remarkable absence of bifurcose in L. perenne tissues might be explained by a higher affinity of 6G-FFT, as compared with 6-SFT, for 1-kestotriose, which is the first fructan formed. Surprisingly, recombinant 6-SFT from Hordeum vulgare, a plant devoid of fructans with internal glucosyl residues, also produced 6G,6-kestotetraose from sucrose and 6G-kestotriose. In the presence of recombinant L. perenne 6G-FFT, it produced 6G,6-kestotetraose from 1-kestotriose and sucrose, like L. perenne 6-SFT. Thus, we demonstrate that the two 6-SFTs have close catalytic properties and that the distinct fructans formed in L. perenne and H. vulgare can be explained by the presence of 6G-FFT activity in L. perenne and its absence in H. vulgare. PMID:21196473

  15. Towards a better understanding of the generation of fructan structure diversity in plants: molecular and functional characterization of a sucrose:fructan 6-fructosyltransferase (6-SFT) cDNA from perennial ryegrass (Lolium perenne).

    PubMed

    Lasseur, Bertrand; Lothier, Jérémy; Wiemken, Andres; Van Laere, André; Morvan-Bertrand, Annette; Van den Ende, Wim; Prud'homme, Marie-Pascale

    2011-03-01

    The main storage compounds in Lolium perenne are fructans with prevailing β(2-6) linkages. A cDNA library of L. perenne was screened using Poa secunda sucrose:fructan 6-fructosyltransferase (6-SFT) as a probe. A full-length Lp6-SFT clone was isolated as shown by heterologous expression in Pichia pastoris. High levels of Lp6-SFT transcription were found in the growth zone of elongating leaves and in mature leaf sheaths where fructans are synthesized. Upon fructan synthesis induction, Lp6-SFT transcription was high in mature leaf blades but with no concomitant accumulation of fructans. In vitro studies with the recombinant Lp6-SFT protein showed that both 1-kestotriose and 6G-kestotriose acted as fructosyl acceptors, producing 1- and 6-kestotetraose (bifurcose) and 6G,6-kestotetraose, respectively. Interestingly, bifurcose formation ceased and 6G,6-kestotetraose was formed instead, when recombinant fructan:fructan 6G-fructosyltransferase (6G-FFT) of L. perenne was introduced in the enzyme assay with sucrose and 1-kestotriose as substrates. The remarkable absence of bifurcose in L. perenne tissues might be explained by a higher affinity of 6G-FFT, as compared with 6-SFT, for 1-kestotriose, which is the first fructan formed. Surprisingly, recombinant 6-SFT from Hordeum vulgare, a plant devoid of fructans with internal glucosyl residues, also produced 6G,6-kestotetraose from sucrose and 6G-kestotriose. In the presence of recombinant L. perenne 6G-FFT, it produced 6G,6-kestotetraose from 1-kestotriose and sucrose, like L. perenne 6-SFT. Thus, we demonstrate that the two 6-SFTs have close catalytic properties and that the distinct fructans formed in L. perenne and H. vulgare can be explained by the presence of 6G-FFT activity in L. perenne and its absence in H. vulgare.

  16. Determination and characterization of cysteine, glutathione and phytochelatins (PC₂₋₆) in Lolium perenne L. exposed to Cd stress under ambient and elevated carbon dioxide using HPLC with fluorescence detection.

    PubMed

    Ju, Xue Hai; Tang, Shirong; Jia, Yan; Guo, Junkang; Ding, Yongzhen; Song, Zhengguo; Zhao, Yujie

    2011-06-15

    Metal-binding thiols, involved in detoxification mechanisms in plant and other organism under heavy metal stress, are receiving more and more attentions, and various methods have been developed to determine related thiols such as cysteine (Cys), glutathione (GSH) and phytochelatins (PCs). In present study, an HPLC method was established for simultaneous determination of Cys GSH and PC(2-6) after treatment with disulfide reductant of tris (2-carboxyethyl) phosphine hydrochloride (TCEP) and thiolyte reagent of monobromobimane (mBBr). The separation of thiol derivatives was performed on an Agilent Zorbax Eclipse XDB-C18 column (4.6 mm × 30 mm, 1.8 μm) with a linear gradient elution of 0.1% (v/v) trifluoroacetic acid (TFA)-acetonitrile (ACN) at 0.8 mL min(-1). The temperature of the column was maintained at 25°C. The excitation and emission wavelengths were set at 380 and 470 nm, respectively. The thiol derivatives were well separated in 19 min, and the total analysis time was 30 min. The established method was proved selective, specific and reproducible, and could be applicable to determine Cys, GSH and PC(2-6) and to evaluate their roles in detoxification mechanisms in Cd-treated Lolium perenne L. under ambient and elevated carbon dioxide (CO(2)). It was found that the total SH contents and proportions of thiols in roots and shoots were dependent on Cd concentration, whereas the total SH contents decreased and the proportions of thiols altered without significance at elevated CO(2) level.

  17. Population paradoxes.

    PubMed

    Meyer, P A

    1992-07-01

    The global population growth rate began accelerating rapidly early this century, passed 1% around 1940, and peaked at around 2.1% in the latter half of the 1960s, when the world's population was about 4 billion. Since then, the growth rate has declined slowly to the present estimate of 1.7%, and now the figure is nearly 5.5 billion. The first population paradox is that the annual increments in global population are still increasing, even though the rate of growth has begun to decline. In the late 1960s the annual increment was about 80 million and the 1992 figures equaled 93.5 million. This annual increment will probably begin to decline before the turn of the century, but will still remain above 80 million until about 2020. Most of these added people will be in the developing countries, (80-90 million every year), most of them in poverty. Demographers now believe that humanity will achieve global replacement-level fertility around the year 2040, given current trends. By 2040 the population will be about 9 billion. They expect an ultimate world population sometime late next century of about 11 billion. The less optimistic scenarios have global replacement-level fertility delayed to 2060, yielding an ultimate population of 12.5 billion. Indonesia is a good example of the optimistic category. It will achieve replacement-level fertility perhaps by the year 2005. In the mid 1970s the annual growth rates were still increasing, peaking at over 2.3%. At that time, Indonesia was growing at 3.5 million people per year. The growth rate is now below 1.7% and, with the population at about 180 million, the annual increments are just 3 million. Indonesia began this century with a population of around 40 million, and will end it with a population around 210 million. Indonesia's ultimate population will be well in excess of 300 million, indicating the force of momentum.

  18. Population Blocks.

    ERIC Educational Resources Information Center

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  19. Population Blocks.

    ERIC Educational Resources Information Center

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  20. Population Dynamics

    PubMed Central

    Juliano, Steven A.

    2007-01-01

    This chapter reviews aspects of population dynamics that may be conceptually important for biological control of mosquitoes. Density dependent population regulation among immature stages has important implications for biological control of mosquito populations, primarily because it can lead to compensatory or overcompensatory mortality due to additions of a biological control agent. This can result in control efforts leading to no change in the target population, or actual increases in the target population, respectively. Density dependent effects, and compensatory or overcompensatory mortality, appear to be most common in mosquitoes from container or highly ephemeral habitats. In permanent ground water habitats generalist predators appear to limit mosquito populations and so render mortality additive. Thus, biological control in permanent ground water habitats seems to have the highest likelihood of producing a satisfactory result. A central premise of classical biological control is that pest populations are reduced by enemies to stable equilibrium levels that are both below the pre-control equilibrium level, and well below the level producing detrimental effects. This premise results in predictions that successful biological control is likely to involve specialist enemies (usually parasitoids), with short generation times relative to the victim, high rates of successful search, rapid rates of increase, and needing only a few victims to complete their life cycle. These predictions largely fail for mosquito systems, in which successful biological control seems to be associated with generalist enemies that can kill a large portion of the target population, often causing local extinction, and can persist in the absence of the target organism. Biological control of mosquitoes appears to be inherently unstable, thus contrasting sharply with classical biological control. This review suggests a need for better data on density dependent regulation of mosquito populations

  1. Population policy.

    PubMed

    1987-03-01

    Participants in the Seminar on Population Policies for Top-level Policy Makers and Program Managers, meeting in Thailand during January 1987, examined the challenges now facing them regarding the implementation of fertility regulation programs in their respective countries -- Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, and Thailand. This Seminar was organized to coincide with the completion of an Economic and Social Commission for Asia and the Pacific (ESCAP) study investigating the impact and efficiency of family planning programs in the region. Country studies were reviewed at the Seminar along with policy issues about the status of women, incentive and disincentive programs, and socioeconomic factors affecting fertility. In Bangladesh the government recognizes population growth as its top priority problem related to the socioeconomic development of the country and is working to promote a reorientation strategy from the previous clinic-oriented to a multidimensional family welfare program. China's family planning program seeks to postpone marraige, space the births of children between 3-5 years, and promote the 1-child family. Its goal is to reduce the rate of natural increase from 12/1000 in 1978 to 5/1000 by 1985 and 0 by 2000. India's 7th Five-Year-Plan (1986-90) calls for establishing a 2-child family norm by 2000. In Indonesia the government's population policy includes reducing the rate of population growth, achieving a redistribution of the population, adjusting economic factors, and creating prosperous families. The government of Indonesia reversed its policy to reduce the population growth rate in 1984 and announced its goal of achieving a population of 70 million by 2100 in order to support mass consumption industries. It has created an income tax deduction system favoring large families and maternity benefits for women who have up to 5 children as incentives. Nepal's official policy is to

  2. A population geographer's population pyramid.

    PubMed

    Sternstein, L

    1989-07-01

    A population geographer cannot depend on the standard population profile because it does not reflect spatial distribution of the desired characteristics. A more revealing approach is the modified box-and- whisker plot with the vertical lines of the box placed at the 1st and 3rd quartiles and the whiskers defining the variance. The geography of the age-sex structure variability in Thailand was examined using this method and by mapping and classifying all the age-sex structures. Classification of these structures includes comparing adjacent age-sex group differences, determining population profiles at each significance level, and spatially portraying each population structure. If the profile includes a 10th or more of the districts, it is called a uniform population profile. One should not generalize over a wide grouping of data because data is not normally regular. Geographical mapping given a usable description of the findings only when appropriate subdivisions of the data are utilized.

  3. Differential composition of bacterial communities as influenced by phenanthrene and dibenzo[a,h]anthracene in the rhizosphere of ryegrass (Lolium perenne L.).

    PubMed

    Corgié, S C; Beguiristain, T; Leyval, C

    2006-12-01

    Bioremediation technologies of Polycyclic Aromatic Hydrocarbons (PAH) are often limited by the recalcitrance to biodegradation of high molecular weight (HMW) PAH. Rhizosphere is known to increase the biodegradation of PAH but little is known about the biodegradability of these HMW compounds by rhizosphere bacteria. This study compared the effects of a 3 and a 5-ring PAH, phenanthrene (PHE) and dibenzo[a,h]anthracene (dBA) respectively, on the composition of bacterial community, the bacterial density and the biodegradation activity. Compartmentalized devices were designed to harvest three consecutive sections of the rhizosphere. Rhizosphere and non-rhizosphere compartments were filled with PHE or dBA spiked or unspiked sand and inoculated with a soil bacterial inoculum. Different bacterial communities and degradation values were found 5 weeks after spiking with PHE (41-76% biodegradation) and dBA (12-51% biodegradation). In sections closer to the root surface, bacterial populations differed as a function of the distance to roots and the PAH added, whereas in further rhizosphere sections, communities were closer to those of the non-planted treatments. Biodegradation of PHE was also a function of the distance to roots, and decreased from 76 to 42% within 9 mm from the roots. However, biodegradation of dBA was significantly higher in the middle section (3-6 mm from roots) than the others. Rhizosphere degradation of PAH varies with the nature of the PAH, and C fluxes from roots could limit the degradation of dBA.

  4. Bioaccumulation of metals in ryegrass (Lolium perenne L.) following the application of lime stabilised, thermally dried and anaerobically digested sewage sludge.

    PubMed

    Healy, M G; Ryan, P C; Fenton, O; Peyton, D P; Wall, D P; Morrison, L

    2016-08-01

    The uptake and accumulation of metals in plants is a potential pathway for the transfer of environmental contaminants in the food chain, and poses potential health and environmental risks. In light of increased population growth and urbanisation, the safe disposal of sewage sludge, which can contain significant levels of toxic contaminants, remains an environmental challenge globally. The aims of this experiment were to apply municipal sludge, having undergone treatment by thermal drying, anaerobic digestion, and lime stabilisation, to permanent grassland in order to assess the bioaccumulation of metals (B, Al, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Nb, Mo, Sb, Ba, W, Pb, Fe, Cd) by perennial ryegrass over a period of up to 18 weeks after application. The legislation currently prohibits use of grassland for fodder or grazing for at least three weeks after application of treated sewage sludge (biosolids). Five treatments were used: thermally dried (TD), anaerobically digested (AD) and lime stabilised (LS) sludge all from one wastewater treatment plant (WWTP), AD sludge from another WWTP, and a study control (grassland only, without application of biosolids). In general, there was no significant difference in metal content of the ryegrass between micro-plots that received treated municipal sludge and the control over the study duration. The metal content of the ryegrass was below the levels at which phytotoxicity occurs and below the maximum levels specified for animal feeds.

  5. [Population education].

    PubMed

    Niang, M

    1992-12-01

    Africa has the highest population growth rate in the world (3%). It has 650 million people (about 900 million in 2000). Rapid population growth has serious consequences which, if not addressed, will be disastrous. This worrisome situation has led some governments to adopt demographic policies to slow down population growth. The UN Economic, Scientific and Cultural Organization (UNESCO) recommends that schools provide population education. Various population conferences have popularized population education in schools among African countries. UNESCO began its regional program on population education in Africa in 1969. National family life and population education (FL/PE) projects have increased from 4 in 1970 to 32 in 1990 (17 in French- and Portuguese-speaking Africa and 5 in English-speaking Africa). These projects teach students about the links between demographic problems and socioeconomic factors and contemporary culture. They aim for total development of the individual and improvement of the quality of life for the individual, family, and community. Topics covered in FL/PE are birth rate; fertility; health; and maternal, infant, and child mortality; unwanted pregnancy; illegal abortion; sexually transmitted diseases; rural-urban migration; and urbanization. Benin introduced FL/PE at all levels of its education system while Senegal, Guinea, Mauritania, and Zaire introduced it to only the primary and secondary school levels. Some countries teach FL/PE as one discipline while most countries (e.g., Senegal) have integrated it into other disciplines (e.g., geography). FL/PE should begin in primary schools because they have the most students and prepare students for middle schools, which provide FL/PE. Elementary education in Senegal is being overhauled to introduce current major problems bit by bit. Senegal also wants to incorporate FL/PE into literacy and adult education programs. Integration of FL/PE into other disciplines should be encouraged.

  6. Population growth.

    PubMed

    1984-01-01

    Despite efforts to reduce population growth, the World Bank projects a world population of 10 billion by 2050, with 7 billion living in developing countries. From October 1979 to September 1984, the US Agency for International Development (AID) funded the Research Triangle Institute's (RTI) Integrated Population and Development Planning (IPDP) project to assess rapid population growth effects in 25 developing countries. In October 1984, US AID extended funding for the program, nicknamed INPLAN, for 3 years, at a cost of $6.3 million. Up to 50% of people in developing countries are under age 15, a fact that guarantees large population increases for the next 50-75 years. Also, many regions have been slow to correlate high fertility with socioeconomic development, and in some areas, fertility is actually increasing. INPLAN aims to make governments more aware of population dynamics and to provide training and tools for effective development planning. 40% of INPLAN's work will be done in Africa, 25% in Latin America, and 20% in Asia, with some activity in the Near East. One project in Egypt, involving the use of model generation by microcomputer, was developed by RTI to show rural to urban migration and rapid population growth affects on the educational system. INPLAN expects to develop several other planning sector models on labor force and employment, health and family planning, food supply, housing, and urban development, and apply them to 20-25 countries. Another project provided 9 microcomputer systems and training to Nigerian government agencies. IMPLAN will purchase and distribute 60 such systems in the future.

  7. Temperature control of the development of frost hardiness in two populations of Leptospermum scoparium.

    PubMed

    Greer, D H; Robinson, L A

    1995-06-01

    Seedlings of Leptospermum scoparium J.R. et G. Forst (manuka) originating from seed from a low altitude coastal site (Auckland) and from a high altitude inland site (Desert Road) were grown for 96 days in four controlled environments to compare the relationship between growth temperature and frost hardening. Day/night temperature treatments were 12/6, 12/3, 12/0 and 12/-3 degrees C. Frost hardiness was determined at 14-day intervals by exposing whole seedlings to temperatures ranging from -2 to -8 degrees C. Frost damage differed significantly between the two populations: Desert Road seedlings were less affected than Auckland seedlings. At all growth temperatures, the time courses of frost hardiness of both populations followed curvilinear relationships reaching a maximum hardiness at about Day 50, after which the seedlings spontaneously dehardened. The rate of frost hardening increased linearly with decreasing temperature from 6 to 0 degrees C, but thereafter, no further increase occurred with decreasing temperature to -3 degrees C. The frost hardening process was more sensitive to temperature in the Desert Road seedlings than in the Auckland seedlings, and this difference may account for the intraspecific variation in frost hardening capacity of this species. Comparisons with Pinus radiata D. Don and Lolium perenne L. indicated that interspecific variation in frost hardening capacity can also be accounted for by differences in the sensitivity of the hardening process to temperature.

  8. Seasonal Abundance and Phenology of Oebalus pugnax (Hemiptera: Pentatomidae) on Graminaceous Hosts in the Delta Region of Mississippi

    PubMed Central

    Awuni, G. A.; Gore, J.; Cook, D.; Musser, F.; Bond, J.

    2015-01-01

    The rice stink bug, Oebalus pugnax (F.), is a graminaceous feeder, and the most injurious insect pest of heading rice, Oryza sativa L., in the United States. Rice growers are aware of the economic importance of host grasses in O. pugnax abundance. However, the need for increased knowledge of host sequence relative to O. pugnax abundance is vital. Densities of O. pugnax on 15 graminaceous hosts were evaluated in the central Mississippi Delta from April through August in 2011 and 2012. Two cultivated and 13 wild host grasses were sampled using a sweep net. Overall, populations of O. pugnax were lower in 2012 than in 2011. Italian ryegrass, Lolium perenne L. ssp. multiflorum (Lambert), was the main host that supported O. pugnax survival and reproduction from overwintering to early summer. Echinochloa spp., Digitaria spp., and Eriochloa spp. maintained greater populations of O. pugnax in the summer. Browntop millet, Urochloa ramosa (L.) Nguyen, and broadleaf signalgrass, U. platyphylla (Munro ex C. Wright) R. D. Webster, were important for populations of O. pugnax populations immediately prior to overwintering. Host switching was also an important factor that contributed to O. pugnax abundance. The evolution of Italian ryegrass resistance to the broad spectrum herbicide glyphosate in the central Mississippi delta has become an important component of O. pugnax population dynamics because of its increased abundance in and around agricultural areas. Cultural control measures on host grasses before flowering could result in less use of insecticides, thereby reducing cost of rice production. PMID:26314038

  9. Seasonal Abundance and Phenology of Oebalus pugnax (Hemiptera: Pentatomidae) on Graminaceous Hosts in the Delta Region of Mississippi.

    PubMed

    Awuni, G A; Gore, J; Cook, D; Musser, F; Bond, J

    2015-08-01

    The rice stink bug, Oebalus pugnax (F.), is a graminaceous feeder, and the most injurious insect pest of heading rice, Oryza sativa L., in the United States. Rice growers are aware of the economic importance of host grasses in O. pugnax abundance. However, the need for increased knowledge of host sequence relative to O. pugnax abundance is vital. Densities of O. pugnax on 15 graminaceous hosts were evaluated in the central Mississippi Delta from April through August in 2011 and 2012. Two cultivated and 13 wild host grasses were sampled using a sweep net. Overall, populations of O. pugnax were lower in 2012 than in 2011. Italian ryegrass, Lolium perenne L. ssp. multiflorum (Lambert), was the main host that supported O. pugnax survival and reproduction from overwintering to early summer. Echinochloa spp., Digitaria spp., and Eriochloa spp. maintained greater populations of O. pugnax in the summer. Browntop millet, Urochloa ramosa (L.) Nguyen, and broadleaf signalgrass, U. platyphylla (Munro ex C. Wright) R. D. Webster, were important for populations of O. pugnax populations immediately prior to overwintering. Host switching was also an important factor that contributed to O. pugnax abundance. The evolution of Italian ryegrass resistance to the broad spectrum herbicide glyphosate in the central Mississippi delta has become an important component of O. pugnax population dynamics because of its increased abundance in and around agricultural areas. Cultural control measures on host grasses before flowering could result in less use of insecticides, thereby reducing cost of rice production.

  10. Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use

    PubMed Central

    Hurkuck, Miriam; Brümmer, Christian; Mohr, Karsten; Spott, Oliver; Well, Reinhard; Flessa, Heinz; Kutsch, Werner L

    2015-01-01

    We applied a 15N dilution technique called “Integrated Total Nitrogen Input” (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7 mg N pot−1) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2 mg N pot−1. Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55 kg N ha−1 yr−1. Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5–10 kg N ha−1 yr−1. PMID:26257870

  11. Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use.

    PubMed

    Hurkuck, Miriam; Brümmer, Christian; Mohr, Karsten; Spott, Oliver; Well, Reinhard; Flessa, Heinz; Kutsch, Werner L

    2015-07-01

    We applied a (15)N dilution technique called "Integrated Total Nitrogen Input" (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7 mg N pot(-1)) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2 mg N pot(-1). Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55 kg N ha(-1) yr(-1). Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5-10 kg N ha(-1) yr(-1).

  12. Population aging.

    PubMed

    1999-04-01

    This paper focuses on the impact of population aging in China, the most densely populated country in the world. Statistics indicate that by the end of 1998, 83.75 million out of the 1.248 billion Chinese people will be over 65 years old. According to the UN standards, China will soon become an aging society. The aging population poses several challenges to the country with the greatest challenge being the increasing social responsibility to care for the aged. With the undeveloped legislative framework to protect the interests of the aged and the serious drawbacks in the pension system to cater only to the income part and not the service part of the aged, China is not yet ready for the advent of aging. Violation of the rights of senior citizens is still very rampant despite enactment of the law on Protection of the Rights of the Elderly in 1996. Moreover, China is not economically ready to become an aging society. China faces this challenge by adopting a three-pronged approach to solve the problem namely: family support, establishment of nursing homes, and creating a social security framework that addresses the needs of the society suited to the Chinese condition. It is believed that with the growing economy of the country and the rising income of its people, a comprehensive social security net will be created to take care of the aged.

  13. Kampuchea: population.

    PubMed

    The United Nations High Commission for Refugees (UNHCR) recently reported that Kampuchea has an estimated population of 6 million. The count was made to determine future United Nations aid to Kampuchea. The count, made by administrators in Kampuchea's 19 provinces, reached a total of 6.4 million versus the 5.75 million estimated by the central government in Phnom Penh. The population estimate made by the Kampuchea provincial administrators surprised observers of the country, including UN representatives, in view of the country's decade of experience with war and destruction, which took a heavy toll on the population; the fatalities in the Vietnamese invasion of 1979, and the ensuing famine of that year. The 1979 vital statistics of Kampuchea are presented in Table 1. Kampuchean refugees at the Thai border camps were reported to be reluctant to go back to their country in spite of reports of good foodgrain harvests and improved prospects for living. The refugees' main concern was their fear and hate of both the Vietnamese troops and the Khmer Rouge.

  14. Controlled release fertilizer increased phytoremediation of petroleum-contaminated sandy soil.

    PubMed

    Cartmill, Andrew D; Cartmill, Donita L; Alarcón, Alejandro

    2014-01-01

    A greenhouse experiment was conducted to determine the effect of the application of controlled release fertilizer [(CRF) 0, 4,6, or 8 kg m(-3)] on Lolium multiflorum Lam. survival and potential biodegradation of petroleum hydrocarbons (0, 3000, 6000, or 15000 mg kg(-1)) in sandy soil. Plant adaptation, growth, photosynthesis, total chlorophyll, and proline content as well as rhizosphere microbial population (culturable heterotrophic fungal and bacterial populations) and total petroleum hydrocarbon (TPH)-degradation were determined. Petroleum induced-toxicity resulted in reduced plant growth, photosynthesis, and nutrient status. Plant adaptation, growth, photosynthesis, and chlorophyll content were enhanced by the application of CRF in contaminated soil. Proline content showed limited use as a physiological indicator of petroleum induced-stress in plants. Bacterial and filamentous fungi populations were stimulated by the petroleum concentrations. Bacterial populations were stimulated by CRF application. At low petroleum contamination, CRF did not enhance TPH-degradation. However, petroleum degradation in the rhizosphere was enhanced by the application of medium rates of CRF, especially when plants were exposed to intermediate and high petroleum contamination. Application of CRF allowed plants to overcome the growth impairment induced by the presence of petroleum hydrocarbons in soils.

  15. Impact of No-till Cover Cropping of Italian Ryegrass on Above and Below Ground Faunal Communities Inhabiting a Soybean Field with Emphasis on Soybean Cyst Nematodes

    PubMed Central

    Hooks, Cerruti R. R.; Wang, Koon-Hui; Meyer, Susan L. F.; Lekveishvili, Mariam; Hinds, Jermaine; Zobel, Emily; Rosario-Lebron, Armando; Lee-Bullock, Mason

    2011-01-01

    Two field trials were conducted between 2008 and 2010 in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop to reduce populations of plant-parasitic nematodes while enhancing beneficial nematodes, soil mites and arthropods in the foliage of a no-till soybean (Glycine max) planting. Preplant treatments were: 1) previous year soybean stubble (SBS); and 2) herbicide-killed IR cover crop + previous year soybean stubble (referred to as IR). Heterodera glycines population densities were very low and no significant difference in population densities of H. glycines or Pratylenchus spp. were observed between IR and SBS. Planting of IR increased abundance of bacterivorous nematodes in 2009. A reverse trend was observed in 2010 where SBS had higher abundance of bacterivorous nematodes and nematode richness at the end of the cover cropping period. Italian ryegrass also did not affect insect pests on soybean foliage. However, greater populations of spiders were found on soybean foliage in IR treatments during both field trials. Potential causes of these findings are discussed. PMID:23430284

  16. Transcriptomes of Lolium/Schedonorus/Festuca species

    USDA-ARS?s Scientific Manuscript database

    ESTs from normalized cDNA libraries of tall fescue with Neotyphodium coenophialum and meadow fescue with Epichloë festucae have been sequenced. The meadow fescue libraries were from RNA isolated from immature tillers of meadow fescue symbiotic with E. festucae, displaying normal inflorescences and ...

  17. Transcriptomes of Lolium/Schedonorus/Festuca species

    USDA-ARS?s Scientific Manuscript database

    Molecular tools for forage grasses are presently sparse. In order to make available these tools for the community, a large scale sequencing effort has been conducted. Roughly 140,000 cDNA clones from normalized libraries obtained from meadow fescue/Epichloe festucae inflorescences and stromata and t...

  18. Transcriptomes of Lolium/Schedonorus/Festuca Species

    USDA-ARS?s Scientific Manuscript database

    ESTs from normalized cDNA libraries of tall fescue with Neotyphodium coenophialum and meadow fescue with Epichloë festucae have been sequenced. The meadow fescue libraries were from RNA isolated from immature tillers of meadow fescue symbiotic with E. festucae, displaying normal inflorescences and ...

  19. Does White Clover (Trifolium repens) Abundance in Temperate Pastures Determine Sitona obsoletus (Coleoptera: Curculionidae) Larval Populations?

    PubMed Central

    McNeill, Mark R.; van Koten, Chikako; Cave, Vanessa M.; Chapman, David; Hodgson, Hamish

    2016-01-01

    To determine if host plant abundance determined the size of clover root weevil (CRW) Sitona obsoletus larval populations, a study was conducted over 4 years in plots sown in ryegrass (Lolium perenne) (cv. Nui) sown at either 6 or 30 kg/ha and white clover (Trifolium repens) sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October) when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand) with % clover measured in autumn (April) and spring (September) of each year. Overall, mean larval densities measured in spring 2012–2015 were 310, 38, 59, and 31 larvae m-2, respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3, and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October) larval populations to % white clover measured in each plot in autumn (April) found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012–2014 larval populations, observed densities tended to be higher than predicted, but the numbers came

  20. Does White Clover (Trifolium repens) Abundance in Temperate Pastures Determine Sitona obsoletus (Coleoptera: Curculionidae) Larval Populations?

    PubMed

    McNeill, Mark R; van Koten, Chikako; Cave, Vanessa M; Chapman, David; Hodgson, Hamish

    2016-01-01

    To determine if host plant abundance determined the size of clover root weevil (CRW) Sitona obsoletus larval populations, a study was conducted over 4 years in plots sown in ryegrass (Lolium perenne) (cv. Nui) sown at either 6 or 30 kg/ha and white clover (Trifolium repens) sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October) when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand) with % clover measured in autumn (April) and spring (September) of each year. Overall, mean larval densities measured in spring 2012-2015 were 310, 38, 59, and 31 larvae m(-2), respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3, and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October) larval populations to % white clover measured in each plot in autumn (April) found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012-2014 larval populations, observed densities tended to be higher than predicted, but the numbers came

  1. Phytoremediation of the polluted Waigang River and general survey on variation of phytoplankton population.

    PubMed

    Hu, Changwei; Ou, Yuxiong; Zhang, Dayi; Zhang, Hui; Yan, Cheng; Zhao, Yongjun; Zheng, Zheng

    2012-11-01

    The Waigang River, a major tributary of the Qinhuai River system, has suffered from long-standing pollution because of lack of management. Restoration was commenced in April 2006 to reduce pollutants and improve water quality. Four ecological areas and ten surface carriers were constructed for the culture of plants (mainly water hyacinth (Eichhornia crassipes) and ryegrass (Lolium perenne L.)) for phytoremediation. Chemical oxygen demand (COD), total suspended solids (TSS), total phosphorus, total nitrogen (TN), ammonia-nitrogen (NH(3)-N), water transparency, and variations in phytoplankton population were investigated to evaluate the effects of restoration. Over 36 months, TSS, COD, TN, and NH(3)-N levels decreased by 91.1, 55.3, 91.5, and 86.5 %, respectively. Transparency increased from 25 cm in 2006 to 165 cm in 2009. Improvements in water quality significantly enhanced the diversity of phytoplankton, which were harmed by pollution stress. Our results show that the water hyacinth and ryegrass cultured in the ecological areas and the surface carriers can be used to restore other heavily polluted rivers with conditions similar to those of the Waigang River, especially in the initial stages of restoration.

  2. Population strategy.

    PubMed

    Kunii, C

    1989-12-01

    In this article, Chojiro Kunii, chairman and executive director of the Japanese Organization for International Cooperation in Family Planning (JOICFP), briefly describes the evolution of the INtegrated Family Planning, Nutrition, and Parasite Control Project (IP). The IP project began in Japan during the post-war period, when midwives and public health nurses introduced family planning alongside maternal and child health care services to make it more acceptable to people. Based on Japan's experience, JOICFP formed an international cooperation project based on parasite control, family planning, and nutrition. Introduced in several Asian countries in the mid-1970s, the project was quickly transported to Central and South America. And in 1983, Africa witnesses its first IP project. This took place in the Masama district of Tanzania, where the results of deworming quickly captures the attention of the population, making it easier for family planning workers to spread their message. In the 2 regions where the IP project was introduced, contraceptive prevalence among women has increased from 9.3% to 33%, and from 27% to 60%. Tanzania is now considering incorporating the IP project in its next 5-year development plan. Other African countries have followed suit. Kunii explains that JOICFP's Ip project enjoys support from both IPPF and UNFPA. He adds that, for its 2nd stage of development, the IP project hopes to become a union of family planning and preventive health. This new phase can already be observed in Asian countries. In developing its population strategy, JOICFP learned from the experience' of Japan, which demonstrated the importance of balancing quantity and quality.

  3. A Novel Multivariate Approach to Phenotyping and Association Mapping of Multi-Locus Gametophytic Self-Incompatibility Reveals S, Z, and Other Loci in a Perennial Ryegrass (Poaceae) Population

    PubMed Central

    Thorogood, Daniel; Yates, Steven; Manzanares, Chloé; Skot, Leif; Hegarty, Matthew; Blackmore, Tina; Barth, Susanne; Studer, Bruno

    2017-01-01

    Self-incompatibility (SI) is a mechanism that many flowering plants employ to prevent fertilisation by self- and self-like pollen ensuring heterozygosity and hybrid vigour. Although a number of single locus mechanisms have been characterised in detail, no multi-locus systems have been fully elucidated. Historically, examples of the genetic analysis of multi-locus SI, to make analysis tractable, are either made on the progeny of bi-parental crosses, where the number of alleles at each locus is restricted, or on crosses prepared in such a way that only one of the SI loci segregates. Perennial ryegrass (Lolium perenne L.) possesses a well-documented two locus (S and Z) gametophytic incompatibility system. A more universal, realistic proof of principle study was conducted in a perennial ryegrass population in which allelic and non-allelic diversity was not artificially restricted. A complex pattern of pollinations from a diallel cross was revealed which could not possibly be interpreted easily per se, even with an already established genetic model. Instead, pollination scores were distilled into principal component scores described as Compatibility Components (CC1-CC3). These were then subjected to a conventional genome-wide association analysis. CC1 associated with markers on linkage groups (LGs) 1, 2, 3, and 6, CC2 exclusively with markers in a genomic region on LG 2, and CC3 with markers on LG 1. BLAST alignment with the Brachypodium physical map revealed highly significantly associated markers with peak associations with genes adjacent and four genes away from the chromosomal locations of candidate SI genes, S- and Z-DUF247, respectively. Further significant associations were found in a Brachypodium distachyon chromosome 3 region, having shared synteny with Lolium LG 1, suggesting further SI loci linked to S or extensive micro-re-arrangement of the genome between B. distachyon and L. perenne. Significant associations with gene sequences aligning with marker

  4. Population Genetics with Fluctuating Population Sizes

    NASA Astrophysics Data System (ADS)

    Chotibut, Thiparat; Nelson, David R.

    2017-05-01

    Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless favor fixation of one species over the other. In this case, a separation of timescales emerges naturally and allows adiabatic elimination of a fast population size variable to deduce the fluctuation-induced selection dynamics near the equilibrium population size. The results highlight the incompleteness of the standard population genetics with a strictly fixed population size.

  5. Population Genetics with Fluctuating Population Sizes

    NASA Astrophysics Data System (ADS)

    Chotibut, Thiparat; Nelson, David R.

    2017-02-01

    Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless favor fixation of one species over the other. In this case, a separation of timescales emerges naturally and allows adiabatic elimination of a fast population size variable to deduce the fluctuation-induced selection dynamics near the equilibrium population size. The results highlight the incompleteness of the standard population genetics with a strictly fixed population size.

  6. Cross-resistance profile of mesosulfuron-methyl-resistant Italian ryegrass in the southern United States.

    PubMed

    Kuk, Yong In; Bugos, Nilda R

    2007-04-01

    Diclofop-resistant Lolium species (ryegrass) is a major weed problem in wheat production worldwide. This study was conducted to determine the resistance pattern of diclofop-resistant ryegrass accessions from the southern United States to mesosulfuron-methyl, a recently commercialized herbicide for ryegrass control in wheat; to determine the cross-resistance pattern of a Lolium multiflorum Lam. (Italian ryegrass) accession, 03-1, to acetolactate synthase (ALS) and acetyl-CoA carboxylase (ACCase) inhibitors; and to determine the resistance mechanism of Italian ryegrass to mesosulfuron-methyl. Seventeen ryegrass accessions from Arkansas and Louisiana, including standard resistant and susceptible accessions, were used in this experiment. Fourteen of the 17 accessions were more resistant (four- to > 308-fold) to diclofop than the standard susceptible biotype. One accession, 03-1, was resistant to mesosulfuron-methyl as well as to other ALS inhibitor herbicides such as chlorsulfuron, imazamox and sulfometuron. Accession 03-1, however, did not show multiple resistance to the ACCase inhibitor herbicides diclofop, fluazifop, clethodim, sethoxydim and pinoxaden, nor to glyphosate. The in vivo ALS activity of the 03-1 biotype was less affected by mesosulfuron-methyl than the susceptible biotype. This indicates that the resistance mechanism of Italian ryegrass to mesosulfuron-methyl is partly due to an alteration in the target enzyme, ALS. It is concluded that diclofop-resistant ryegrass in the southern United States can be generally controlled by mesosulfuron-methyl. However, mesosulfuron-methyl must be used with caution because not all ryegrass populations are susceptible to it. There is a need for more thorough profiling of ryegrass resistance to herbicides.

  7. Natural enemies act faster than endophytic fungi in population control of cereal aphids.

    PubMed

    Härri, Simone A; Krauss, Jochen; Müller, Christine B

    2008-05-01

    1. Fast-growing populations of phytophagous insects can be limited by the presence of natural enemies and by alkaloids that are produced by symbiotic associations of many temperate grass species with endophytic fungi. It is unclear if and how acquired plant defences derived from endophytic fungi interact with natural enemies to affect phytophagous insect populations. 2. To assess the relative importance of endophytic fungi compared to that of natural enemies on the population dynamics of phytophagous insects, we carried out a fully factorial field experiment, in which the presence of natural enemies and the presence of endophytic fungi were manipulated simultaneously. Target colonies of aphids were monitored for 8 weeks starting from their natural appearance in the field to the end of the aphid season. 3. We show that on Lolium perenne increased natural enemy densities reduced the individual numbers of two common cereal aphids, Rhopalosiphum padi and Metopolophium festucae. 4. The presence of the endophytic fungi Neotyphodium lolii reduced the number of M. festucae but did not affect the number of R. padi. The reduction in R. padi numbers by predators and parasitoids was not influenced by the presence of endophytes. For adult M. festucae, however, the negative effects of natural enemies were significant only in the absence of endophytes. 5. Over the duration of the experiment, the effect of natural enemies on aphid colony growth was much stronger than the effect of the endophytic fungi N. lolii, presumably because predator and parasitoid action on aphid colonies is much faster than any effects of endophytes. 6. Our results demonstrate that with simultaneous action of acquired endosymbionts and natural enemies, both factors can control aphid colony growth but they generally act independently of each other.

  8. Inherited fungal symbionts enhance establishment of an invasive annual grass across successional habitats.

    PubMed

    Uchitel, Andrea; Omacini, Marina; Chaneton, Enrique J

    2011-02-01

    Plants infected with vertically transmitted fungal endophytes carry their microbial symbionts with them during dispersal into new areas. Yet, whether seed-borne endophytes enhance the host plant's ability to overcome colonisation barriers and to regenerate within invaded sites remains poorly understood. We examined how symbiosis with asexual endophytic fungi (Neotyphodium) affected establishment and seed loss to predators in the invasive annual grass Lolium multiflorum (Italian ryegrass) across contrasting successional plots. Italian ryegrass seeds with high and low endophyte incidence were sown into three communities: a 1-year-old fallow field, a 15-year-old grassland, and a 24-year-old forest, which conformed to an old-field chronosequence in the eastern Inland Pampa, Argentina. We found that endophyte infection consistently increased host population recruitment and reproductive output. Endophyte presence also enhanced aerial biomass production of ryegrass in a low recruitment year but not in a high recruitment year, suggesting that symbiotic effects on growth performance are density dependent. Endophyte presence reduced seed removal by rodents, although differential predation may not account for the increased success of infected grass populations. Overall, there was no statistical evidence for an endophyte-by-site interaction, indicating that the fungal endosymbiont benefitted host establishment regardless of large differences in biotic and abiotic environment among communities. Our results imply that hereditary endophytes may increase the chances for host grass species to pass various ecological filters associated with invasion resistance across a broad range of successional habitats.

  9. Glyphosate-resistant weeds of South American cropping systems: an overview.

    PubMed

    Vila-Aiub, Martin M; Vidal, Ribas A; Balbi, Maria C; Gundel, Pedro E; Trucco, Frederico; Ghersa, Claudio M

    2008-04-01

    Herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. In South America, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. The goal of this report is to review the current knowledge on cases of evolved glyphosate-resistant weeds in South American agriculture. The first reports of glyphosate resistance include populations of highly diverse taxa (Lolium multiflorum Lam., Conyza bonariensis L., C. canadensis L.). In all instances, resistance evolution followed intense glyphosate use in fruit fields of Chile and Brazil. In fruit orchards from Colombia, Parthenium hysterophorus L. has shown the ability to withstand high glyphosate rates. The recent appearance of glyphosate-resistant Sorghum halepense L. and Euphorbia heterophylla L. in glyphosate-resistant soybean fields of Argentina and Brazil, respectively, is of major concern. The evolution of glyphosate resistance has clearly taken place in those agroecosystems where glyphosate exerts a strong and continuous selection pressure on weeds. The massive adoption of no-till practices together with the utilization of glyphosate-resistant soybean crops are factors encouraging increase in glyphosate use. This phenomenon has been more evident in Argentina and Brazil. The exclusive reliance on glyphosate as the main tool for weed management results in agroecosystems biologically more prone to glyphosate resistance evolution.

  10. Global Population Profile: 2002. International Population Reports

    ERIC Educational Resources Information Center

    Christenson, Matthew; McDevitt, Thomas; Stanecki, Karen

    2004-01-01

    Global Population Profile: 2002 summarizes the most important trends in global population at the dawn of the 21st century. The presentation is organized around four themes: (1) Global Population; (2) Growth, Global Population; (3) Composition, Contraceptive Prevalence in the Developing World; and (4) the AIDS Pandemic in the 21st Century. This…

  11. Effective population size of korean populations.

    PubMed

    Park, Leeyoung

    2014-12-01

    Recently, new methods have been developed for estimating the current and recent changes in effective population sizes. Based on the methods, the effective population sizes of Korean populations were estimated using data from the Korean Association Resource (KARE) project. The overall changes in the population sizes of the total populations were similar to CHB (Han Chinese in Beijing, China) and JPT (Japanese in Tokyo, Japan) of the HapMap project. There were no differences in past changes in population sizes with a comparison between an urban area and a rural area. Age-dependent current and recent effective population sizes represent the modern history of Korean populations, including the effects of World War II, the Korean War, and urbanization. The oldest age group showed that the population growth of Koreans had already been substantial at least since the end of the 19th century.

  12. Nutrients can enhance the abundance and expression of alkane hydroxylase CYP153 gene in the rhizosphere of ryegrass planted in hydrocarbon-polluted soil.

    PubMed

    Arslan, Muhammad; Afzal, Muhammad; Amin, Imran; Iqbal, Samina; Khan, Qaiser M

    2014-01-01

    Plant-bacteria partnership is a promising strategy for the remediation of soil and water polluted with hydrocarbons. However, the limitation of major nutrients (N, P and K) in soil affects the survival and metabolic activity of plant associated bacteria. The objective of this study was to explore the effects of nutrients on survival and metabolic activity of an alkane degrading rhizo-bacterium. Annual ryegrass (Lolium multiflorum) was grown in diesel-contaminated soil and inoculated with an alkane degrading bacterium, Pantoea sp. strain BTRH79, in greenhouse experiments. Two levels of nutrients were applied and plant growth, hydrocarbon removal, and gene abundance and expression were determined after 100 days of sowing of ryegrass. Results obtained from these experiments showed that the bacterial inoculation improved plant growth and hydrocarbon degradation and these were further enhanced by nutrients application. Maximum plant biomass production and hydrocarbon mineralization was observed by the combined use of inoculum and higher level of nutrients. The presence of nutrients in soil enhanced the colonization and metabolic activity of the inoculated bacterium in the rhizosphere. The abundance and expression of CYP153 gene in the rhizosphere of ryegrass was found to be directly associated with the level of applied nutrients. Enhanced hydrocarbon degradation was associated with the population of the inoculum bacterium, the abundance and expression of CYP153 gene in the rhizosphere of ryegrass. It is thus concluded that the combination between vegetation, inoculation with pollutant-degrading bacteria and nutrients amendment was an efficient approach to reduce hydrocarbon contamination.

  13. Early vs. asymptotic growth responses of herbaceous plants to elevated CO[sub 2

    SciTech Connect

    Thomas, S.C.; Jasienski, M.; Bazzaz, F.A. . Dept. of Organismic and Evolutionary Biology)

    1999-07-01

    Although many studies have examined the effects of elevated carbon dioxide on plant growth,'' the dynamics of growth involve at least two parameters, namely, an early rate of exponential size increase and an asymptotic size reached late in plant ontogeny. The common practice of quantifying CO[sub 2] responses as a single response ratio thus obscures two qualitatively distinct kinds of effects. The present experiment examines effects of elevated CO[sub 2] on both early and asymptotic growth parameters in eight C[sub 3] herbaceous plant species (Abutilon theophrasti, Cassia obtusifolia, Plantago major, Rumex crispus, Taraxacum officinale, Dactylis glomerata, Lolium multiflorum, and Panicum dichotomoflorum). Plants were grown for 118--172 d in a factorial design of CO[sub 2] (350 and 700 [micro]L/L) and plant density (individually grown vs. high-density monocultures) under edaphic conditions approximating those of coastal areas in Massachusetts. For Abutilon theophrasti, intraspecific patterns of plant response were also assessed using eight genotypes randomly sampled from a natural population and propagated as inbred lines.

  14. Nutrients Can Enhance the Abundance and Expression of Alkane Hydroxylase CYP153 Gene in the Rhizosphere of Ryegrass Planted in Hydrocarbon-Polluted Soil

    PubMed Central

    Arslan, Muhammad; Afzal, Muhammad; Amin, Imran; Iqbal, Samina; Khan, Qaiser M.

    2014-01-01

    Plant-bacteria partnership is a promising strategy for the remediation of soil and water polluted with hydrocarbons. However, the limitation of major nutrients (N, P and K) in soil affects the survival and metabolic activity of plant associated bacteria. The objective of this study was to explore the effects of nutrients on survival and metabolic activity of an alkane degrading rhizo-bacterium. Annual ryegrass (Lolium multiflorum) was grown in diesel-contaminated soil and inoculated with an alkane degrading bacterium, Pantoea sp. strain BTRH79, in greenhouse experiments. Two levels of nutrients were applied and plant growth, hydrocarbon removal, and gene abundance and expression were determined after 100 days of sowing of ryegrass. Results obtained from these experiments showed that the bacterial inoculation improved plant growth and hydrocarbon degradation and these were further enhanced by nutrients application. Maximum plant biomass production and hydrocarbon mineralization was observed by the combined use of inoculum and higher level of nutrients. The presence of nutrients in soil enhanced the colonization and metabolic activity of the inoculated bacterium in the rhizosphere. The abundance and expression of CYP153 gene in the rhizosphere of ryegrass was found to be directly associated with the level of applied nutrients. Enhanced hydrocarbon degradation was associated with the population of the inoculum bacterium, the abundance and expression of CYP153 gene in the rhizosphere of ryegrass. It is thus concluded that the combination between vegetation, inoculation with pollutant-degrading bacteria and nutrients amendment was an efficient approach to reduce hydrocarbon contamination. PMID:25360680

  15. The Effect of Marigolds (Tagetes spp.) and Other Cover Crops on Pratylenchus penetrans and on Following Potato Crops

    PubMed Central

    Kimpinski, J.; Arsenault, W. J.; Gallant, C. E.; Sanderson, J. B.

    2000-01-01

    Root-lesion nematodes (primarily Pratylenchus penetrans) were monitored in two marigold cultivars (Tagetes tenuifolia cv. Nemakill and cv. Nemanon), annual ryegrass (Lolium multiflorum cv. Lemtal), red clover (Trifolium pratense cv. Florex), and soybean (Glycine max cv. Proteus), and in the following potato (Solanum tuberosum cv. Superior) crop during three growth sequences. Meadow fescue (Festuca elatior cv. Miner) and bee plant (Phacelia tanacetifolia cv. Gipha) were added to the trial in the second year. Black-eyed Susan (Rudbeckia hirta, unidentified cv.) and two additional marigold cultivars (T. patula ssp. nana, unidentified cv., and T. erecta cv. Crackerjack) were included in the final sequence. Population levels of root-lesion nematodes were consistently lower under marigolds compared to the other cover crops tested. Correspondingly, average potato tuber yields were significantly higher (8-14%) when potato followed marigolds. The highest levels of root-lesion nematodes occurred under red clover and soybean, and the average potato tuber yields were lowest following these crops. PMID:19271006

  16. Population control II: The population establishment today.

    PubMed

    Hartmann, B

    1997-01-01

    Although population assistance represents a relatively small share of official development assistance, it influences many other aspects of development planning. The organizations that comprise the population establishment have a common purpose--the reduction of population growth in the Third World--but they are not homogeneous and sometimes have conflicting goals and strategies. National governments, multilateral agencies, nongovernmental organizations, foundations, academic centers, and pressure groups all contribute to creating and sustaining what has become a virtual population control industry. Through scholarships, travel grants, awards, and favorable publicity, Third World elites have been encouraged to join the population establishment. The World Bank, the U.S. Agency for International Development, and the U.N. Fund for Population Activities have pursued explicit strategies for pressuring Third World governments to design and implement population policies, most recently in Africa.

  17. Predicting Population Curves.

    ERIC Educational Resources Information Center

    Bunton, Matt

    2003-01-01

    Uses graphs to involve students in inquiry-based population investigations on the Wisconsin gray wolf. Requires students to predict future changes in the wolf population, carrying capacity, and deer population. (YDS)

  18. Predicting Population Curves.

    ERIC Educational Resources Information Center

    Bunton, Matt

    2003-01-01

    Uses graphs to involve students in inquiry-based population investigations on the Wisconsin gray wolf. Requires students to predict future changes in the wolf population, carrying capacity, and deer population. (YDS)

  19. Simulating Population Growth.

    ERIC Educational Resources Information Center

    Byington, Scott

    1997-01-01

    Presents a strategy to help students grasp the important implications of population growth. Involves an interactive demonstration that allows students to experience exponential and logistic population growth followed by a discussion of the implications of population-growth principles. (JRH)

  20. Some Current Population Trends.

    ERIC Educational Resources Information Center

    Taeuber, Conrad

    Population trends in the 1960's and early 1970's are examined in this 1972 speech in terms of overall national trends, the growth of metropolitan areas, the rural population, geographic shifts, internal migration, the black population, and living arrangements. It is noted that population growth in the 1960's was unevenly distributed within age…

  1. WHAT IS A POPULATION?

    EPA Science Inventory

    The word "population" has several meanings, a situation that can lead to confusion in risk assessments. A management goal "to protect wildlife populations," for example, might relate to populations as defined by population biologists, or it might mean simply to protect animals in...

  2. Human Population Problems

    ERIC Educational Resources Information Center

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

    Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

  3. Human Population Problems

    ERIC Educational Resources Information Center

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

    Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

  4. WHAT IS A POPULATION?

    EPA Science Inventory

    The word "population" has several meanings, a situation that can lead to confusion in risk assessments. A management goal "to protect wildlife populations," for example, might relate to populations as defined by population biologists, or it might mean simply to protect animals in...

  5. Understanding Rural Population Loss.

    ERIC Educational Resources Information Center

    McGranahan, David A.; Beale, Calvin L.

    2002-01-01

    A quarter of nonmetro counties lost population in the 1990s, but population loss was not related to poverty rate or low educational levels, perhaps because low-skill workers can no longer expect better wages in urban areas. Population loss was related to low population density and remoteness (which decrease access to services), lack of natural…

  6. The Population Reference Bureau's Population Handbook.

    ERIC Educational Resources Information Center

    Haupt, Arthur; Kane, Thomas T.

    This handbook offers information on population dynamics. The population data resource is intended for use by journalists, policymakers, teachers, high school and college students, libraries, advertising agencies, and family planning groups. The document is presented in 12 sections. Section I introduces demography, explains the purpose and scope of…

  7. The Population Reference Bureau's Population Handbook.

    ERIC Educational Resources Information Center

    Haupt, Arthur; Kane, Thomas T.

    This handbook offers information on population dynamics. The population data resource is intended for use by journalists, policymakers, teachers, high school and college students, libraries, advertising agencies, and family planning groups. The document is presented in 12 sections. Section I introduces demography, explains the purpose and scope of…

  8. Equine palmar artery, palmar vein and uterine artery express different populations of vasoactive biogenic amine receptors

    USDA-ARS?s Scientific Manuscript database

    Consumption of endophyte-infected (Neotyphodium coenophialum) tall fescue (Lolium arundinaceum) seed by horses causes constriction of the palmar artery (PA), palmar vein (PV) and reduced blood flow to the corpus luteum that can be measured in vivo by Doppler ultrasonography. In addition, myograph st...

  9. Ambient has become strained. Identification of Acacia dealbata Link volatiles interfering with germination and early growth of native species.

    PubMed

    Souza-Alonso, Pablo; González, Luís; Cavaleiro, Carlos

    2014-09-01

    Acacia dealbata Link is a widespread invader in Mediterranean type ecosystems, and traits promoting its invasiveness are currently under investigation. Due to the dense atmosphere below its canopy, we hypothesized that volatile organic compounds (VOCs) released from flowers, leaves, litter, or a mixture of treatments exert inhibitory effects on the natives Trifolium subterraneum, Lolium multiflorum, Medicago sativa, and also on its own seeds. We reported that VOCs from flowers significantly reduced germination in L. multiflorum and A. dealbata; moreover, root length, stem length, aboveground and belowground biomass were also reduced in all species studied. Volatile organic compounds from flowers and the mixture also increased significantly malondialdehyde content in T. subterraneum and L. multiflorum. The effects of VOCs on antioxidant enzymatic activities were species dependent. Flowers enhanced peroxidase but decreased superoxide dismutase activity in T. subterraneum. In contrast, VOCs released from leaves increased the activity of superoxide dismutase in L. multiflorum. GC/MS analyses revealed 27 VOCs in the volatile fraction from flowers, 12 of which were exclusive to this fraction. Within them, heptadecadiene, n-nonadecane, n-tricosane, and octadecene represent 62% of the fraction. We present evidence that the VOCs released from A. dealbata flowers strongly inhibited germination and seedling growth of selected species, and mainly on its own seedlings. As far as we know, this is the first evidence of phytotoxicity induced by VOCs in invasive species belonging to the Acacia genus.

  10. A study of the human immune response to Lolium perenne (rye) pollen and its components, Lol p I and Lol p II (Rye I and Rye II). II. Longitudinal variation of antibody levels in relation to symptomatology and pollen exposure and correction of seasonally elevated antibody levels to basal values.

    PubMed

    Freidhoff, L R; Ehrlich-Kautzky, E; Meyers, D A; Marsh, D G

    1987-11-01

    This study used a standardized, dialyzed, Lolium perenne (ryegrass) pollen extract and two of its well-characterized components, Lol p I (Rye I) and Lol p II (Rye II), to characterize the longitudinal variation of both IgE and IgG antibody (Ab) levels, as well as total serum IgE levels, in 20 grass-allergic subjects followed for 13 months. Ab levels declined toward a basal level just before, and increased just after, the grass-pollination season, returning to the same basal level just before the next grass-pollination season. The least complex allergen, Lol II, demonstrated the most uniform pattern of variation in both IgE and IgG Ab levels. Total serum IgE levels demonstrated the least regular pattern of variation. Grass-pollen counts were strongly correlated with symptom-medication scores for these subjects (rs = 0.87). Initial values were correlated with the rise in total IgE and IgE Ab to Lol II across the grass-pollen season. Skin test results were correlated with initial IgE Ab levels for L. perenne pollen extract and Lol II. Finally, a procedure for correcting IgE Ab levels to basal values was proposed and tested. The correction procedure, for each IgE Ab, was based on the average rise during the grass-pollination season (or average decline after the grass-pollination season) observed for all subjects with that IgE Ab.

  11. Population and population policy in Pakistan.

    PubMed

    Mauldin, W P

    1963-02-01

    Pakistan is a divided country with different religious groups represented. Since independence in 1941, the Muslim population has increased more rapidly than the Hindu population, the West Pakistan population more rapidly and steadily than the East Pakistan population. In the late 1950s the Pakistan government initiated a family planning program. The program has trained medical and paramedical personnel in family planning, added family planning services to existing medical centers, planned for a National Research Institute of Family Planning, employed mobile units to reach outlying areas, conducted limited clinical studies on some contraceptives, and used mass media advertising. Only India and Japan are doing more with government-sponsored family planning. A weak organizational structure and an inadequate number of trained personnel are the main weakness of the program. It is too early to assess the success of the program. A 10-point reduction in annual birth rates will be considered successful.

  12. [Population trends in Luxembourg].

    PubMed

    1989-01-01

    Population trends in Luxembourg in 1988 are reviewed. Separate consideration is given to fertility, nuptiality and divorce, mortality, natural increase and migration, adoption, age and sex structure, and spatial distribution. Data are provided separately for the foreign resident population.

  13. The Growing Human Population.

    ERIC Educational Resources Information Center

    Keyfitz, Nathan

    1989-01-01

    Discusses the issue of human population. Illustrates the projections of the growing human population in terms of developed and less developed countries. Describes the family planning programs in several countries. Lists three references for further reading. (YP)

  14. Population Education Software Reviews.

    ERIC Educational Resources Information Center

    Inter-Change, 1985

    1985-01-01

    Provides critiques, price lists, and computer requirements for selected population education software programs. Reviewed programs include: Demo-graphics; Malthus; Coexist; Rice Farming; Popgro; Manrgy; Population Growth; and Simpolicon. Addresses of the distributors are also provided. (ML)

  15. Glaucoma in Asian Populations

    MedlinePlus

    ... Us Donate In This Section Glaucoma In Asian Populations email Send this article to a friend by ... an even more serious problem as the world population and longevity increases. The other major glaucoma type ...

  16. The Growing Human Population.

    ERIC Educational Resources Information Center

    Keyfitz, Nathan

    1989-01-01

    Discusses the issue of human population. Illustrates the projections of the growing human population in terms of developed and less developed countries. Describes the family planning programs in several countries. Lists three references for further reading. (YP)

  17. Alternative population futures.

    PubMed

    1980-01-01

    Alternative population scenarios to the year 2000 are presented and policy implications of the various scenarios are discussed. Population models are described. Projections are made based on different sets of assumptions regarding changes in birth, death, marriage and migration rates. A "high" series, "medium" series and "low" series of projections are made for total population. Projections are also made regarding urban and rural population, families and households, and the labor force.

  18. Controlling Population with Pollution

    ERIC Educational Resources Information Center

    Browne, Joseph

    2010-01-01

    Population models are often discussed in algebra, calculus, and differential equations courses. In this article we will use the human population of the world as our application. After quick looks at two common models we'll investigate more deeply a model which incorporates the negative effect that accumulated pollution may have on population.

  19. Modeling Exponential Population Growth

    ERIC Educational Resources Information Center

    McCormick, Bonnie

    2009-01-01

    The concept of population growth patterns is a key component of understanding evolution by natural selection and population dynamics in ecosystems. The National Science Education Standards (NSES) include standards related to population growth in sections on biological evolution, interdependence of organisms, and science in personal and social…

  20. Teaching about Population Growth.

    ERIC Educational Resources Information Center

    Otero, George G., Jr., Comp.

    This teaching guide contains 20 activities on population growth for students in grades 6-12. The purpose is to help students gain the skills, knowledge, and understanding of population dynamics so that they can make rational decisions and take responsible action regarding population matters and public policy. Activities are organized around the…

  1. Population: A Lively Introduction.

    ERIC Educational Resources Information Center

    McFalls, Joseph A., Jr.

    1991-01-01

    The study of demography must begin with an understanding of the three sources of population changes: fertility, mortality, and migration. This paper leads prospective demographers--or anyone interested in population--through the dynamics of these three variables, introducing them to the forces that cause populations to grow or decline, and that…

  2. Teaching about Population Issues.

    ERIC Educational Resources Information Center

    Otero, George G., Jr., Comp.

    This teaching guide on population issues contains 19 activities for students in grades 7-12. The objective is to analyze population issues that have resulted from human population dynamics. In this guide, four categories of activities are included: some are discussion starters, some provide factual data, some focus on thinking skills, and some are…

  3. Teaching Population Geography.

    ERIC Educational Resources Information Center

    Carey, George W.; Schwartzberg, Julie

    Written under the sponsorship of the Population Council, with the financial support of the Population Instructional Materials Project, this work is intended to provide the thoughtful teacher of the social sciences with some suggestions and techniques for introducing population study to students in terms of concrete case studies which explore the…

  4. Teaching about Population Issues.

    ERIC Educational Resources Information Center

    Otero, George G., Jr., Comp.

    This teaching guide on population issues contains 19 activities for students in grades 7-12. The objective is to analyze population issues that have resulted from human population dynamics. In this guide, four categories of activities are included: some are discussion starters, some provide factual data, some focus on thinking skills, and some are…

  5. Populations, Teacher's Guide.

    ERIC Educational Resources Information Center

    Conard, David; Lawson, Chester A.

    This Teacher's Guide is designed for use with the Science Curriculum Improvement Study's (SCIS) unit Population. Populations is the third of a six-unit sequence of SCIS's Life Science Program for grades K-6. The Populations guide consists of activity outlines along with suggestions for guiding children's observation and manipulations of living…

  6. Population Education Country Programmes.

    ERIC Educational Resources Information Center

    Population Education in Asia and the Pacific Newsletter, 1985

    1985-01-01

    Discusses population education programs in China, India, Indonesia, Maldives, Nepal, Pakistan, Philippines, Sri Lanka, and Vietnam. Sri Lanka is developing audio-visual materials and integrating population education into secondary science and social studies curricula. Nepal is transmitting nonformal population education messages to adults through…

  7. Teaching Population Geography.

    ERIC Educational Resources Information Center

    Carey, George W.; Schwartzberg, Julie

    Written under the sponsorship of the Population Council, with the financial support of the Population Instructional Materials Project, this work is intended to provide the thoughtful teacher of the social sciences with some suggestions and techniques for introducing population study to students in terms of concrete case studies which explore the…

  8. Controlling Population with Pollution

    ERIC Educational Resources Information Center

    Browne, Joseph

    2010-01-01

    Population models are often discussed in algebra, calculus, and differential equations courses. In this article we will use the human population of the world as our application. After quick looks at two common models we'll investigate more deeply a model which incorporates the negative effect that accumulated pollution may have on population.

  9. Planning for Growing Populations.

    ERIC Educational Resources Information Center

    Cassen, Robert, Ed.; Wolfson, Margaret, Ed.

    The basic needs and services that the vast masses of the population in developing countries must have to improve their quality of life are examined. Chapter 1 of nine chapters discusses implications of rapid population growth for social and economic planning. Rapid population growth in the developing countries is discussed in chapter 2. Food…

  10. Impact of Population Growth

    ERIC Educational Resources Information Center

    Ehrlich, Paul R.; Holdren, John P.

    1971-01-01

    Discusses the interrelated crises in population growth, natural resources, and environmental quality. Major problems include population control, redirection of technology, closed resource cycles, equitable opportunity distribution and prosperity. Population growth is regarded as causing a disportionate world-wide negative environmental impact.…

  11. Modeling Exponential Population Growth

    ERIC Educational Resources Information Center

    McCormick, Bonnie

    2009-01-01

    The concept of population growth patterns is a key component of understanding evolution by natural selection and population dynamics in ecosystems. The National Science Education Standards (NSES) include standards related to population growth in sections on biological evolution, interdependence of organisms, and science in personal and social…

  12. Population and Environment

    PubMed Central

    de Sherbinin, Alex; Carr, David; Cassels, Susan; Jiang, Leiwen

    2009-01-01

    The interactions between human population dynamics and the environment have often been viewed mechanistically. This review elucidates the complexities and contextual specificities of population-environment relationships in a number of domains. It explores the ways in which demographers and other social scientists have sought to understand the relationships among a full range of population dynamics (e.g., population size, growth, density, age and sex composition, migration, urbanization, vital rates) and environmental changes. The chapter briefly reviews a number of the theories for understanding population and the environment and then proceeds to provide a state-of-the-art review of studies that have examined population dynamics and their relationship to five environmental issue areas. The review concludes by relating population-environment research to emerging work on human-environment systems. PMID:20011237

  13. Molecular Population Genetics.

    PubMed

    Casillas, Sònia; Barbadilla, Antonio

    2017-03-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. Copyright © 2017 Casillas and Barbadilla.

  14. Molecular Population Genetics

    PubMed Central

    Casillas, Sònia; Barbadilla, Antonio

    2017-01-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. PMID:28270526

  15. Population 101. A primer.

    PubMed

    Gelbard, A

    1997-09-01

    This article summarizes basic statistics on population growth, concepts about population momentum, and evidence of fertility declines in the world. World population was about 5.84 billion in mid-1997. 86 million people are added yearly. Almost 1 billion people are added every 11 years. The first billion was reached in the early 1800s, and each billion took fewer and fewer years to attain. World population is expected to expand until about 2050 and level off after 2150. Dramatic declines in death rates and health improvements contributed to smaller numbers of children per woman. Absolute increases are due to population momentum, which is the continued large concentration of women in the childbearing years. World population will continue to grow, even after replacement-level fertility of 2 children/woman is reached, due to population momentum. Developing countries continue to have a young age structure and high birth rates, which result in higher population growth. 35% of population in developing countries is aged under 15 years, and almost 50% of population in sub-Saharan African countries is aged under 15 years. Fertility has declined in most regions, with the exception of sub-Saharan Africa. All developing regions have above replacement-level fertility. Declines to below replacement-level fertility in developed countries is attributed to improvements in health for women and children, greater use of family planning, and more education for women and girls. Fertility is high where infant mortality is high. Family planning allows mothers to have healthier children.

  16. Population education country programmes.

    PubMed

    1980-12-01

    Population education country programs in the countries of India, Malaysia, Nepal, the Philippines, and Sri Lanka are reviewed. In India the machinery is beginning to roll for the nationwide implementation of a 3-year national population education project. A variety of strategies will be used at the national and state levels using existing facilities and infrastructure for implementing various aspects of the program. Recommendations and proposed project activities arrived at during 2 workshop/training programs are outlined. The Malaysian population education program recently developed a working draft of the scope, content, and objectives of population education at the primary and lower and upper secondary levels. This working draft is being pretested among teachers and curriculum developers, and, once revised, it will serve as the overall guiding framework for those responsible for preparing curriculum and instructional materials on population education. The population education program in Nepal will be implemented by 3 units: Curriculum, Textbook, Supervision, and Development Center; Tribhuvan University; and Division of Adult Education. The longterm objective is to institutionalize population education in the formal and nonformal education programs including the university. The Population Education Program of the Philippines has prepared a reader in Filipino for grade 3 pupils. Population education in the country has been promoted to a lesser degree in private than in public schools. the Institutional Development Program of the Population Center Foundation conducted a Summer Institute in Instructional Product Development for the primary purpose of institutionalizing population in the social science curriculum at the tertiary level. The population education program of Sri Lanka will undergo a revival in the recently approved 2-year project agreement between Sri Lanka's government and the United Nations Fund for Population Activities.

  17. Population information resources.

    PubMed

    Pasquariella, S K

    1984-12-01

    This article describes print and computerized services that are dedicated to bibliographic coverage of 1 or more areas of population studies. Major printed bibliographic information resources for population material include: ADOPT, DOCPAL Resumenes sobre Poblacion en America Latina, PIDSA Abstracts, Population Index and Review of Population Reviews. ADOPT is an annotated computer-aided current-awareness bibliographic journal which has been published monthly since January 1975 by the Regional Population Information Center of the Economic and Social Commission for Asia and the Pacific (ESCAP). DOCPAL Resumenes is a computer-produced biannual collection of abstracts containing indexes and between 600 and 700 summaries of both published and unpublished population documents. PIDSA is intended to make available documentary information about population matters in sub-Saharan Africa. Population Index, 1 of the oldest and most definitive bibliographies in the demography field, is international in scope and is arranged as a classified and annotated bibliography of monographs, journal articles and 2ndary source material relevant to all aspects of demography. Review of Population Reviews, published 4 times a year, are annotated bibliographies containing summaries of articles that have been published in 83 periodicals in 37 countries. Cited articles are assigned subject-heading descriptors from the Population Multilingual Thesaurus. Major computerized information resources are: DOCPAL, DOCPOP, EBIS/POPFILE, MANPINS, POPLINE and POPULATION BIBLIOGRAPHY. DOCPAL was established to assist Latin Ameran countries in the collection, storage, processing and retrieval of population documents about Latin America. DOCPAL contains over 19,000 bibliographic citations. DOCPOP was established as the 1st Latin American national computerized population documentation system for Brazilian material. POPLINE is a computerized retrieval service cooperatively produced in the US which covers the

  18. Population structure in Japanese rice population

    PubMed Central

    Yamasaki, Masanori; Ideta, Osamu

    2013-01-01

    It is essential to elucidate genetic diversity and relationships among even related individuals and populations for plant breeding and genetic analysis. Since Japanese rice breeding has improved agronomic traits such as yield and eating quality, modern Japanese rice cultivars originated from narrow genetic resource and closely related. To resolve the population structure and genetic diversity in Japanese rice population, we used a total of 706 alleles detected by 134 simple sequence repeat markers in a total of 114 cultivars composed of 94 improved varieties and 20 landraces, which are representative and important for Japanese rice breeding. The landraces exhibit greater gene diversity than improved lines, suggesting that landraces can provide additional genetic diversity for future breeding. Model-based Bayesian clustering analysis revealed six subgroups and admixture situation in the cultivars, showing good agreement with pedigree information. This method could be superior to phylogenetic method in classifying a related population. The leading Japanese rice cultivar, Koshihikari is unique due to the specific genome constitution. We defined Japanese rice diverse sets that capture the maximum number of alleles for given sample sizes. These sets are useful for a variety of genetic application in Japanese rice cultivars. PMID:23641181

  19. Absorption and translocation of 4-(trifluoromethyl)chlorobenzene in soil and crops

    SciTech Connect

    Cacco, G.; Ferrari, G.

    1982-01-01

    Water containing 1 mg/L 4-(trifluoro(/sup 14/C)methyl)chlorobenzene (TFCB) was supplied to pot cultures of three grass (Zea mays L.; Festuca rubra L.; Lolium multiflorum L.) and three legume (Vicia sativa L.; Trifolium perenne L.; Medicago sativa L.) species. The chemical was absorbed by soil and subsequently translocated to plant leaves at increasing amounts for maize to ryegrass, clover, alfalfa, red fescue, and vetch. Legumes showed a high capacity of degradation of the contaminant, suggesting their utilization to reclaim soil and water contaminated by TFCB.

  20. Hypertension in special populations.

    PubMed

    Nesbitt, Shawna D

    2005-07-01

    Hypertension is a multifaceted disease that may present somewhat differently in various populations. It is clear that hypertensive treatment reduces cardiovascular, renal, and cerebrovascular outcomes for all patients, yet recent clinical trial data suggest that some groups may benefit more than others from specific drug intervention. Furthermore, these data justify specific approaches for some special populations. This article reviews important features of the presentation, rationale for treatment, and treatment recommendations for the treatment of hypertension in special populations. The special populations addressed include diabetic patients, the elderly, and women.

  1. The population of Croatia.

    PubMed

    Sterc, S; Crkvencic, I

    1996-04-01

    The authors examine historical and current population dynamics in Croatia. "The demographic structure of Croatia indicates a series of specificities which were primarily conditioned by the historical development of Croatia and which is particularly expressed in constant emigration since the end of the nineteenth century, the relatively large direct and indirect losses to the population during and immediately after the First and Second World Wars, emigration as a type of population movement in all inter-census periods after 1945, the appearance of a natural decline and the aging of the population on almost one half of the state territory." excerpt

  2. [Population and development].

    PubMed

    Castanon Romo, R; Sandoval Navarrete, J

    1996-01-01

    This broad survey of the debate concerning the relationship between population growth and economic development discusses the history and current status of world population growth, summarizes several influential theoretical positions on the topic, and proposes that redefinition of women's social role is indispensable if worldwide control of population growth is to be achieved. The introductory section discusses the acceleration of population growth in the second half of the 20th century and the increasing concentration of growth in the poor and developing countries. The positions of those who see in population control a means of promoting economic development and political stability are contrasted to the positions of those who believe that a large and growing population is the key to achieving economic and political progress. The international community, facing great uncertainty about the size, distribution, and well-being of the future world population, is increasingly concerned about the effect of growing numbers on the environment and natural resources. The second section summarizes the works of Malthus, Julian Simon, and the Club of Rome, and analyzes the propositions of demographic transition theory. The conclusion notes that despite uncertainty about the future of world population, development, and health, most of the poorest countries have become aware of the desirability of slowing population growth. A broad redefinition of the social role of women will inevitably accompany the worldwide demographic transition.

  3. Population and development.

    PubMed

    Okita, S

    1989-03-01

    This speech on the life and work of Rafael Salas, who had been the first executive director of the UN Population Fund (UNFPA) and who contributed immensely to global awareness of population as a vital issue, inaugurated the Rafael M. Salas Lecture Series at the UN. Salas was concerned with individual rights and socioeconomic development while maintaining a balance between population and the environment. He built a large multinational assistance program for population activities and increased funding from $2.5 million in 1969 to $175 million to support 2500 projects in 130 developing countries. He organized both the 1974 World Population Conference and the 1984 International Conference on Population. In developing countries malnutrition and poverty are intertwined, lowering productivity and making people prone to diseases. Infant and child mortality rises with the malnutrition of mothers, therefore campaigns modelled after the postwar Japanese efforts are needed to improve nutrition, to train dietitians, and to introduce school lunch programs. Population stabilization could also be achieved in developing countries by raising income levels, although in Latin American countries birth rates have stayed the same despite increasing income. Direct measures are effective in reducing the birth rate: primary school education, increased income, improved nutrition, decline in infant mortality, higher status of women, and decisive governmental population policy. The Club of Rome report The Limits to Growth predicted that sometime in the 21st century a sudden decline in both population and industrial capacity will be reached at the present growth trends.

  4. [Population change in 1990].

    PubMed

    1992-01-01

    Demographic data for 1990 from Belgium's national population register are presented. Data are provided separately by commune, arrondissement, department, and province, and in most cases are broken down by sex for Belgian nationals and foreigners. They concern births, deaths, and natural increase; internal and international migration; changes in nationality; and population estimates.

  5. [Population change in 1991].

    PubMed

    1992-01-01

    Demographic data are presented from the national population register for Belgium for 1991. Information on methodology and definitions is provided. The data, which are presented by commune, arrondissement, province, and region, and separately for Belgians and foreigners, concern natural increase, internal and international migration, and population estimates.

  6. Regional Population Dynamics

    Treesearch

    Andrew Birt

    2011-01-01

    The population dynamics of the southern pine beetle (SPB) exhibit characteristic fluctuations between relatively long endemic and shorter outbreak periods. Populations exhibit complex and hierarchical spatial structure with beetles and larvae aggregating within individual trees, infestations with multiple infested trees, and regional outbreaks that comprise a large...

  7. The World Population Dilemma.

    ERIC Educational Resources Information Center

    Population Reference Bureau, Inc., Washington, DC.

    This book is the third in a series published by the Population Reference Bureau aimed at illuminating the facts and consequences of human population dynamics for secondary and college-age students. Many illustrations, charts and graphs are included in this volume to help the reader grasp a number of the current ideas and concepts that are used in…

  8. Population Education Country Programmes.

    ERIC Educational Resources Information Center

    Population Education in Asia and the Pacific Newsletter, 1983

    1983-01-01

    Highlights various population education programs in Afghanistan, China, India, Malaysia, Sri Lanka, and Vietnam. Also describes population education programs at primary and secondary levels in Thailand, curriculum and instructional materials development in this country, and teaching units and curriculum outlines developed from a workshop for…

  9. Mentoring Special Populations

    ERIC Educational Resources Information Center

    Whitfield, Keith E.; Edwards, Christopher L.

    2011-01-01

    Mentorship is critical for career development. Members of special populations are at increased risk of information shortfalls and advice that is not framed with cultural sensitivity. Special knowledge and skills are needed to successfully mentor members of ethnic minority and other special populations. Midlevel and senior scientists need…

  10. Junior Biology, Populations.

    ERIC Educational Resources Information Center

    Hamilton City Board of Education (Ontario).

    Twenty-one studies related to populations are included in this student manual for a junior high school biology course. Each activity or study provides questions, diagrams, experiments, and/or descriptive material to which the student must respond. Population studies pertain to individual plants and animals, their physical environments, reactions…

  11. Ecology and Population

    ERIC Educational Resources Information Center

    Hawley, Amos H.

    1973-01-01

    Author suggests that study of population growth is not a field of study only for ecologists. Population growth is related with social sciences in the nature of its process and future consequences. Broader, comprehensive approaches to this problem will be useful. (PS)

  12. Selected Resources on Population.

    ERIC Educational Resources Information Center

    Zero Population Growth, Inc., Washington, DC.

    This booklet contains information on K-12 resources for population education. Each of 91 entries contains standard bibliographic information, prices, International Standard Book Numbers, appropriate grade levels, and a short description of the product. Resource areas include: (1) books on population; (2) books on the environment; (3) books geared…

  13. Populations, Teacher's Guide.

    ERIC Educational Resources Information Center

    California Univ., Berkeley. Science Curriculum Improvement Study.

    The Science Curriculum Improvement Study has developed this teacher's guide to "Populations," the third part of a six-unit life science curriculum sequence. The six basic units, emphasizing organism-environment interactions, are organisms, life cycles, populations, environments, communities, and ecosystems; and they make use of…

  14. Population Education Country Programmes.

    ERIC Educational Resources Information Center

    Population Education in Asia and the Pacific Newsletter, 1983

    1983-01-01

    Highlights various population education programs in Afghanistan, China, India, Malaysia, Sri Lanka, and Vietnam. Also describes population education programs at primary and secondary levels in Thailand, curriculum and instructional materials development in this country, and teaching units and curriculum outlines developed from a workshop for…

  15. Population Trends and Prospects.

    ERIC Educational Resources Information Center

    Mauldin, W. Parker

    1980-01-01

    Future trends in population are described as they relate to developed and developing nations. It is suggested that for the next 20 years there will be a decrease in population growth rates for all areas of the world except Africa. (Author/SA)

  16. Why Teach Population Education?

    ERIC Educational Resources Information Center

    Cook-Fuller, Charlotte; And Others

    Population education can help students develop coping skills and make responsible decisions as members of a family, a community, a nation, and a world. For example, by studying and understanding the impact of changes in population growth rates, compositional characteristics, and migration shifts, students, as future citizens, will be better able…

  17. The Population Activist's Handbook.

    ERIC Educational Resources Information Center

    Population Inst., Washington, DC.

    This handbook is a guide to effective action strategies on dealing with overpopulation. Divided into five sections, the book outlines programs, suggests references, and lists resources that are helpful for thinking and for planning action on population issues. Section one focuses on strategies to change the current population policy choices made…

  18. Mentoring Special Populations

    ERIC Educational Resources Information Center

    Whitfield, Keith E.; Edwards, Christopher L.

    2011-01-01

    Mentorship is critical for career development. Members of special populations are at increased risk of information shortfalls and advice that is not framed with cultural sensitivity. Special knowledge and skills are needed to successfully mentor members of ethnic minority and other special populations. Midlevel and senior scientists need…

  19. Population stabilisation: intervention strategies.

    PubMed

    1997-01-01

    This article discusses family planning (FP) program failures, the need for a paradigm change, and new interventions and recommendations. India has failed to significantly change the pattern of population growth. The FP program has failed due to its inability to eliminate illiteracy, to meet the minimum needs of the people, and to communicate with people effectively about health and FP. Four states in India have a particularly serious problem with rapid population growth: Uttar Pradesh, Rajasthan, Madhya Pradesh, and Bihar states, which have 40% of total population and 48% of total illiterate population. In 1993, the Union Minister for Health and Family Welfare appointed a group (Swaminathan Committee) to draft a population policy. The 1994 draft policy emphasized balancing population with the carrying capacity of available land and water supplies; decentralizing; and fulfilling the needs of the people. A new agency was to be formed: the Population and Social Development Commission. A new financing unit was to be established: the Population and Social Development Fund. The Ministry of Health and Family Welfare was to be restructured. The draft program suggested the integration of FP with maternal and child health care and immunization. In 1996, the Department of Family Welfare offered a Statement that ignored many of the provisions of the Swaminathan Committee, but did include the elimination of targets and the promotion of the 2-child family norm. It is recommended that the 1996 Policy Statement be ignored and the Swaminathan Committee draft policy be resurrected.

  20. India's population impact "global".

    PubMed

    1998-01-01

    This article summarizes statistics from the 1998 ESCAP Population Data Sheet. India's present population is slightly under 975 million persons. India is the second most populous country in the world, after China. India began a new era in policy and program content for enhancing fertility decline after the 1994 International Conference on Population and Development. The 1997-2002 Five Year Plan calls for reduction in the population growth rate. The population growth rate, in 1996, was 1.8% annually. By 1991, the population aged 0-14 years was 37%, while the urban population was 26%; female literacy was 39.3% and male literacy was 64.1%. In 1994, the median age at first marriage among women had increased to 19.4 years. Life expectancy for women rose from 36.1 years to 62.9 years during 1951-86. In India, nongovernmental organizations (NGOs) have played a role in implementing family planning programs. Recent changes reflect a greater role of larger NGOs in interacting with and overseeing smaller NGOs. Larger NGOs approve projects, release funds, train, and monitor and evaluate activities. Government policy has shifted to a system of community needs assessment. Disparate contraceptive and maternal and child health programs have been integrated into a reproductive and child health program. Program emphasis is on meeting clients' needs and improving quality of care.

  1. The Population Activist's Handbook.

    ERIC Educational Resources Information Center

    Population Inst., Washington, DC.

    This handbook is a guide to effective action strategies on dealing with overpopulation. Divided into five sections, the book outlines programs, suggests references, and lists resources that are helpful for thinking and for planning action on population issues. Section one focuses on strategies to change the current population policy choices made…

  2. Why Population Matters, 1996.

    ERIC Educational Resources Information Center

    Population Action International, Washington, DC.

    Population growth around the world affects Americans through its impact on economy, environment, safety, and health, and the condition of the world children will inherit. The cumulative evidence is strong that current rates of population growth pose significant and interacting risks to human well-being and are a legitimate concern for Americans.…

  3. The World Population Dilemma.

    ERIC Educational Resources Information Center

    Population Reference Bureau, Inc., Washington, DC.

    This book is the third in a series published by the Population Reference Bureau aimed at illuminating the facts and consequences of human population dynamics for secondary and college-age students. Many illustrations, charts and graphs are included in this volume to help the reader grasp a number of the current ideas and concepts that are used in…

  4. Population. Headline Series.

    ERIC Educational Resources Information Center

    Oppenheimer, Valerie K.

    Useful as background reading or secondary classroom material, this pamphlet reviews several dimensions of world population growth and control. The first of seven chapters, World Population Growth: Past, Present and Future, discusses some of the reasons for the greatly accelerated growth since 1950, and points out that even significantly rapid…

  5. Why Teach Population Education?

    ERIC Educational Resources Information Center

    Cook-Fuller, Charlotte; And Others

    Population education can help students develop coping skills and make responsible decisions as members of a family, a community, a nation, and a world. For example, by studying and understanding the impact of changes in population growth rates, compositional characteristics, and migration shifts, students, as future citizens, will be better able…

  6. Understanding Population Projections.

    ERIC Educational Resources Information Center

    Haub, Carl

    1987-01-01

    Population projections are "what if" computational exercises. Given selected assumptions about future trends in fertility, mortality, and migration, population trends can be projected. Government and business planners need this information, and they also require enough time to put facilities in place to meet future needs. Everyone benefits from a…

  7. Populations, Teacher's Guide.

    ERIC Educational Resources Information Center

    California Univ., Berkeley. Science Curriculum Improvement Study.

    The Science Curriculum Improvement Study has developed this teacher's guide to "Populations," the third part of a six-unit life science curriculum sequence. The six basic units, emphasizing organism-environment interactions, are organisms, life cycles, populations, environments, communities, and ecosystems; and they make use of…

  8. World Population in Transition.

    ERIC Educational Resources Information Center

    Merrick, Thomas W.; And Others

    1986-01-01

    This issue discusses world population trends and their implications for more and less developed countries. There have been two periods of major population expansion since 1750 with the first lasting almost 200 years and the second surge occurring after World War II. Growth rates in industrialized countries are now very low with fertility below…

  9. World Population Crisis.

    ERIC Educational Resources Information Center

    Ehrlich, Paul R.; Ehrlich, Anne H.

    1986-01-01

    Rapid population growth, rising competition for resources, and increasing environmental deterioration are intertwined factors in the human predicament that feed political tensions and conflicts of the late twentieth century. Outlines dimensions of this predicament (including data on population, growth, military spending, quality of life, and…

  10. Teaching Notes on Population.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Center for International Programs and Cooperative Services.

    This newsletter is designed to serve as a clearinghouse for the exchange of ideas and information on new strategies of teaching and instructional resources about population in colleges and universities. The first article discusses some of the contemporary problems faced in teaching population studies to undergraduates. The second article outlines…

  11. HLA population genetics: a Lebanese population.

    PubMed

    Cano, Pedro; Testi, Manuela; Andreani, Marco; Khoriaty, Evelyne; Bou Monsef, Jad; Galluccio, Tiziana; Troiano, Maria; Fernandez-Vina, Marcelo; Inati, Adlette

    2012-10-01

    Human leukocyte antigen (HLA) typing was done in 426 Lebanese subjects of 88 families, in which 347 haplotypes were identified. The A, B, C, DRB1, DRB3/4/5, DQB1 and DPB1 loci were typed at high resolution. This study shows that information theory, as originally developed by Claude Shannon in 1948, provides a promising theoretical foundation to study the population genetics of a genetic system like HLA. Although Lebanese carry HLA alleles found in other populations, the association of these alleles into haplotypes is quite unique. Comparisons are made with the main ethnic groups. Two haplotypes well represented in the Lebanese population are not identified in any global population: L1 = {A*26:01:01 - B*35:01:01:01- C*04:01:01:01- DRB1*16:01:01 - DRB5*02:02 - DQB1*05:02:01} and L2 = {A*02:02 - B*41:01- C*17:01:01:01 -DRB1*11:04:01 - DRB3*02:02:01:01- DQB1*03:01:01:01}. By studying linkage disequilibrium in two blocks at a time, with the division of the blocks at different levels in consecutive cycles, conserved haplotypes in full linkage disequilibrium come to light, such as {A*26:01:01- B*35:01:01:01 - C*04:01:01:01 - DRB1*16:01:01 - DRB5*02:02 - DQB1*05:02:01- DPB1*03:01:01} and {A*33:01:01 - B*14:02:01 - C*08:02:01 - DRB1*01:02:01- DQB1*05:01:01:01 - DPB1*04:01:01:01}. © 2012 John Wiley & Sons A/S.

  12. A study of the human immune response to Lolium perenne (rye) pollen and its components, Lol p I and Lol p II (rye I and rye II). I. Prevalence of reactivity to the allergens and correlations among skin test, IgE antibody, and IgG antibody data.

    PubMed

    Freidhoff, L R; Ehrlich-Kautzky, E; Grant, J H; Meyers, D A; Marsh, D G

    1986-12-01

    In a stratified random sample of 320 white adults, the prevalence of puncture skin test positivity (ST +) to Lolium perenne (rye grass)-pollen extract (LPE) was 16%. Fifteen percent of all subjects (or 84% of subjects classified LPE IgE antibody positive [Ab +]) was classified IgE Ab + to highly purified Lol p I (Rye I), and 4% of all subjects (or 26% of subjects classified LPE IgE Ab +) was classified IgE Ab + to highly purified Lol p II (Rye II). These data and similar results obtained in an allergy-enriched group of 361 subjects are consistent with previous studies that Lol I is a major allergen and Lol II is a minor allergen of LPE. Whether we studied LPE, Lol I, or Lol II, responder subjects were younger than nonresponder subjects and more male than female subjects were responders. We then investigated the quantitative interrelationships among ST, IgE, and IgG Ab responsiveness to LPE, Lol I, and Lol II in the allergy-enriched group. For each allergen, log-log correlations were strong and significant for ST versus IgE Ab and for IgE Ab versus IgG Ab. All subjects IgE Ab + to Lol I or Lol II were IgG Ab + to that allergen, supporting other evidence for a commonality in the genetic control influencing the production of IgE and IgG Abs to a given allergen. Log-log correlations among ST end points, IgE Ab levels, or IgG Ab levels were strong for LPE versus either Lol I or Lol II but weak between Lol I and Lol II, consistent with the reported lack of cross-reactivity between Lol I and Lol II. Despite these findings, almost all Lol II + subjects were Lol I + by ST (98%), IgE Ab (91%), and IgG Ab (83%), suggesting that the Ia-restricted immune recognition of both these molecules is at least in part under a common genetic control.

  13. Cairo: repackaging population control.

    PubMed

    Simons, H

    1995-01-01

    Aid agencies, charities, and other nongovernmental organizations once denounced population control programs as racist interference in the third world. Yet, at the United Nations Conference on Population and Development in Cairo last September, these same organizations endorsed very similar ideas. The U.N. can now claim that even its fiercest critics not only have muted their criticism of population control programs but now positively endorse them. Over the last 30 years, population control has been consciously repackaged by the U.S. establishment. The image of population control has changed from being overtly anti-third world to being about giving the people of the third world--especially women--basic rights in family planning. Wrapped up in the language of women's empowerment and environmentalism, the establishment's old arguments about there being too many nonwhite babies in the world, have, unfortunately, won the day.

  14. Diversity of Poissonian populations

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo I.; Sokolov, Igor M.

    2010-01-01

    Populations represented by collections of points scattered randomly on the real line are ubiquitous in science and engineering. The statistical modeling of such populations leads naturally to Poissonian populations—Poisson processes on the real line with a distinguished maximal point. Poissonian populations are infinite objects underlying key issues in statistical physics, probability theory, and random fractals. Due to their infiniteness, measuring the diversity of Poissonian populations depends on the lower-bound cut-off applied. This research characterizes the classes of Poissonian populations whose diversities are invariant with respect to the cut-off level applied and establishes an elemental connection between these classes and extreme-value theory. The measures of diversity considered are variance and dispersion, Simpson’s index and inverse participation ratio, Shannon’s entropy and Rényi’s entropy, and Gini’s index.

  15. Population geography. Progress reports.

    PubMed

    Nash, A

    1996-06-01

    Improved communication and dissemination of information both among colleagues in the subdiscipline of population geography and to the public can help improve population geography's poor reputation. Population geography scholars tend to write little and often poorly. To make matters worse, most journals in which the articles are published are edited by amateurs. More than half of published articles are never cited, indicating the failure of these scholars to read their colleagues' work. Many articles are written simply to secure tenure or promotion. Population geography scholars instead need to use the full range of available print and electronic publications, as well as research papers, to broaden and enrich their communication. Furthermore, efforts must be made to reach out to the public, albeit without trying to appear too popular to colleagues. The author discusses the North American Free Trade Agreement and Hong Kong, mobility and migration, historical demography, and other aspects of population geography.

  16. Mexico's population policy turnaround.

    PubMed

    Nagel, J S

    1978-12-01

    Until 1972 Mexico's officials seemed to believe that the annual population growth rate of 3.5% was not really a problem as long as the economic development rate could be kept ahead of the population growth rate. The General Law of Population of 1947 was actually promoting population growth. It was only during the 1960s that elite opinion shifted, and privately funded family planning programs became increasingly active. By 1972 the population had reached 54 million, from 20 million in 1940. President Echevarria, till then a traditional pronatalist, announced in 1972 the creation of a national family planning program, and, in 1974, the creation of a national population council. Since then the Mexican government has embarked on ambitious programs of mass communication and sex education to make the population receptive to its new attitudes. The plans have worked: by mid-1979 estimates put the population growth rate at 2.9%, within sight of the 2.5% target set for 1982 by new president Lopez Portillo. According to a survey conducted by the National Fertility Survey, by late 1976 41.50% of Mexican women of childbearing age were practicing contraception. Within the 41.50% of active contraceptors, 14.9% use the pill, and 7.8% the IUD. New channels of information and of contraceptive delivery are being explored to reach Mexico's widely scattered rural population, and to bring the average family size down to 2 children from the average of 6.5 children per woman for 1973-1975. The government goal is of a 1% population increase by the year 2000.

  17. Population post-Rio.

    PubMed

    Myers, N

    1993-01-01

    The June 1993 Rio Earth Summit barely recognized population growth as an issue, despite the evidence that rapid population growth is harming both the environment and development efforts. One reason given for brushing the population issue to the sidelines was that the UN had a major population conference scheduled for 1994. This overlooked the fact that in the interim between the two conferences, the population problem would be compounded by an additional 200 million people. Any delay now will increase the number of potential parents in the future and create an ever-increasing problem. The male participants at Rio who were willing to procrastinate on population issues were joined by feminists who claimed that men should leave this issue to women. These women ignore the fact that men need to be more, not less, involved in family planning. Women need support in increasing their status and in improving educational opportunities for girls. Providing girls with as much education as boys receive in low-income nations would cost less than a quarter of a percent of the collective gross national product of these nations, and this education would provide a solid boast to their economies and to their family planning campaigns. Procrastinators on population issues must stop acting as though a spare planet is available when we overload the earth.

  18. [African population in history].

    PubMed

    Yang, S

    1984-11-29

    The growth rate of the African population has been fluctuating throughout history, affected by political, social, and economic events. 6000 years ago, the majority of the population was based in North Africa, because farming had been developed there. However, between the 11th and the 16th centuries, there was a constant decline in the population of that region, due to invasions from Europe and the black plague. During the same period, the population in the area south of the Sahara grew rapidly, as people there had gone into the iron tool period and farming had been developed. From the 16th to the mid-17th Century, population growth was considerable in Africa; more people had learned the technology of irrigation, corn and potatoes had been introduced from South America, and colonialism was not yet an issue. From the mid-17th to the mid-19th Century, there was no growth, due to the slave trade and wars between tribes. One estimate sets the direct and indirect loss during this period, as a result of the slave trade, at 100 million people. From the 1850s to the end of World War I, population growth started up again, chiefly influenced by the fact that the slave trade had essentially come to a half and modern medical care had become available on the continent. However, in central Africa, the region which suffered the worst blow from the slave trade, growth was very slow, while in East Africa the population was declining because of wars between colonists and natives, as well as natural disasters. Increases in population during this period were a result of immigration from Europe and India. From the end of World War I to the present, growth has been rapid, given improvements in medical services and standards of living, while most of the former colonies became independent after the 1950s. Consequently, almost all African countries are under great pressure now with regard to their populations.

  19. Global population growth.

    PubMed

    Langmore, J

    1992-07-01

    The global population passed 5 billion in 1987. In the year 2000 the world's population will be more than 6 billion, increasing by 90-100 million each year. About 95% of future demographic growth will take place in developing countries. The number of school age children is projected to increase from 940 million in 1980 to 1280 million by the year 2000. Under current labor force growth projections in developing countries, around 1.6 billion new jobs will have to be created between 1980 and 2025, with nearly 1 billion of them in Asia. Population often increases at a more rapid rate than agricultural growth. Food production per capita has declined in 70 developing countries. Much of the projected population increase will take place in environmentally fragile regions of the developing world. Population pressures contribute to deforestation, desertification, and scarcity of clean water. The United Nations Population Fund has estimated that in Asia over 43% of women not using family planning would like to postpone, space, or limit their childbearing. Over half of the world's couples of reproductive age are now using contraception. Family planning to postpone the first birth and to eliminate late child bearing would reduce both child loss and maternal illness and death. Both infant and maternal mortality are greater with higher order births. Reducing average family size is an effective way of reducing infant and maternal mortality. The World Bank has given high priority to population assistance, with large programs in Bangladesh, Egypt, India, Indonesia, the Philippines, and Thailand. Population assistance provided by the Australian International Development Assistance Bureau totaled about $4.5 million during 1989-90 and is expected to be about $8 million during 1991-92. Australia should increase the proportion of its development assistance budget devoted to population, and family planning programs should increase to around $26 million in line with other major donors.

  20. [Trends in population aging].

    PubMed

    Valkovics, E

    1990-11-01

    The age structure of the world population between 1950 and 1985 is analyzed according to changes in fertility, mortality, and international migration in developing and developed countries. "Relying on the results of the medium scenario of the population forecasts prepared by the U.N. Division of International Economic and Social Affairs, the author demonstrates that aging of the world population will become a global phenomenon, characteristic of every region and county of the world, between 1985 and 2025." (SUMMARY IN ENG AND RUS)

  1. The population threat.

    PubMed

    Teitelbaum, M S

    1992-01-01

    Commentary is provided on the challenges faced by the new Clinton administration in formulating US key foreign policy initiatives. There is an urgent need to provide balanced and effective foreign aid for reducing high fertility rates in the developing world. There is also a need to effectively monitor the large migrations of populations. Over the past 10 years, the US has not been actively practicing world leadership on population issues. 3 changes in 1993 give impetus to redirect foreign policy: 1) the waning influence of fringe groups who controlled population issues; 2) the campaign promises to restore UN population stabilization programs; and 3) the evidence from the Persian Gulf and Yugoslavia that demographic issues require planning and assessment. Global population growth has been concentrated in the past 40 years, in part due to mortality declines and sustained high fertility. Of significance is the rapidness and momentum of growth. A high percentage are and will be children. Urban population is also growing rapidly in high fertility countries. Countries with high fertility and significant rural-to-urban migration also have large international migrations. The evolution of policy since the 1950s, which for the most part ignored population issues, is discussed. The American debates have been charged with emotionalism: about human sexuality, legitimacy of voluntary fertility control, the role and status of women and men, abortion, intergenerational transfer of obligations, ethnic solidarity and the sovereignty of national borders, and the proper roles of the state versus the marketplace. There have been over 200 years of ideological argument over population issues. The Malthusian argument was that large population size did not increase prosperity, and growth should be limited. The Marxist-Leninist position was that contraception was Malthusian, abortion was a woman's right, and population growth was neutral. By late 1970 the Chinese Maoists adopted the moral

  2. Modeling Honey Bee Populations

    PubMed Central

    Torres, David J.; Ricoy, Ulises M.; Roybal, Shanae

    2015-01-01

    Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population. PMID:26148010

  3. Populating the whole landscape.

    PubMed

    Brown, Adam R; Dahlen, Alex

    2011-10-21

    Every de Sitter vacuum can transition to every other de Sitter vacuum despite any obstacle, despite intervening anti-de Sitter sinks, despite not being connected by an instanton. Eternal inflation populates the whole landscape. © 2011 American Physical Society

  4. AMPHIBIAN POPULATION DYNAMICS

    EPA Science Inventory

    Agriculture has contributed to loss of vertebrate biodiversity in many regions, including the U.S. Corn Belt. Amphibian populations, in particular, have experienced widespread and often inexplicable declines, range reductions, and extinctions. However, few attempts have been made...

  5. AMPHIBIAN POPULATION DYNAMICS

    EPA Science Inventory

    Agriculture has contributed to loss of vertebrate biodiversity in many regions, including the U.S. Corn Belt. Amphibian populations, in particular, have experienced widespread and often inexplicable declines, range reductions, and extinctions. However, few attempts have been made...

  6. Population approaches in paediatrics.

    PubMed

    Chatelut, Etienne

    2008-12-01

    Population pharmacokinetic (PK) approach is now often used to evaluate PK characteristics of a new compound during its clinical development. Recently, new legislation governing the development and authorization of medicines for use in children aged 0-17 years was introduced in the European Union. Among the strategies proposed in relation to clinical aspects, use of population PKs is stated. In this manuscript, comparison between standard PK and population PK methods will be briefly addressed to understand why the second is particularly adapted to perform PK studies in paediatrics. Then, specific patients' characteristics (covariates) in paediatrics will be presented. Examples of PK and PK-pharmacodynamic (PK-PD) studies will be finally given. The number of population PK studies published still exceeds largely those of PK-PD.

  7. Evolving sparse stellar populations

    NASA Astrophysics Data System (ADS)

    Bruzual, Gustavo; Gladis Magris, C.; Hernández-Pérez, Fabiola

    2017-03-01

    We examine the role that stochastic fluctuations in the IMF and in the number of interacting binaries have on the spectro-photometric properties of sparse stellar populations as a function of age and metallicity.

  8. Population Education. Awareness Activities.

    ERIC Educational Resources Information Center

    Brouse, Deborah E.

    1990-01-01

    Described are awareness activities that deal with human population growth, resources, and the environment. Activities include simulations, mathematical exercises, and discussions of the topic. Specific examples of what individuals can do to help are listed. (KR)

  9. Parallel grid population

    DOEpatents

    Wald, Ingo; Ize, Santiago

    2015-07-28

    Parallel population of a grid with a plurality of objects using a plurality of processors. One example embodiment is a method for parallel population of a grid with a plurality of objects using a plurality of processors. The method includes a first act of dividing a grid into n distinct grid portions, where n is the number of processors available for populating the grid. The method also includes acts of dividing a plurality of objects into n distinct sets of objects, assigning a distinct set of objects to each processor such that each processor determines by which distinct grid portion(s) each object in its distinct set of objects is at least partially bounded, and assigning a distinct grid portion to each processor such that each processor populates its distinct grid portion with any objects that were previously determined to be at least partially bounded by its distinct grid portion.

  10. Modeling Honey Bee Populations.

    PubMed

    Torres, David J; Ricoy, Ulises M; Roybal, Shanae

    2015-01-01

    Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population.

  11. Arbuscular mycorrhiza and petroleum-degrading microorganisms enhance phytoremediation of petroleum-contaminated soil.

    PubMed

    Alarcón, Alejandro; Davies, Fred T; Autenrieth, Robin L; Zuberer, David A

    2008-01-01

    While plants can phytoremediate soils that are contaminated with petroleum hydrocarbons, adding microbes to remediate contaminated sites with petroleum-degrading microorganisms and arbuscular mycorrhizal fungi (AMF) is not well understood. The phytoremediation of Arabian medium crude oil (ACO) was done with a Lolium multiflorum system inoculated with an AMF (Glomus intraradices) and a mixture of petroleum-degrading microorganisms--the bacterium, Sphingomonas paucimobilis (Sp) and the filamentous fungus, Cunninghamella echinulata (Ce, SpCe)--or with a combination of microorganisms (AMF + SpCe). Based on an earlier study on screening plants for phytoremediation of ACO, L. multiflorum (Italian ryegrass) was selected for its tolerance and rapid growth response (Alarcón, 2006). The plants were exposed to ACO-contaminated soil (6000 mg kg(-1)) for 80 d under greenhouse conditions. A modified Long Ashton Nutrient Solution (LANS) was supplied to all treatments at 30 microg P mL(-1), except for a second, higher P, control treatment at 44 microg P mL(-1). Inoculation with AMF, SpCe, or AMF + SpCe resulted in significantly increased leaf area as well as leaf and pseudostem dry mass as compared to controls at 30 microg P mL(-1). Populations of bacteria grown on a nitrogen-free medium and filamentous fungi increased with AMF + SpCe and SpCe treatments. The average total colonization and arbuscule formation of AMF-inoculated plants in ACO-contaminated soil were 25% and 8%, respectively. No adverse effects were caused by SpCe on AMF colonization. Most importantly, ACO degradation was significantly enhanced by the addition of petroleum-degrading microorganisms and higher fertility controls, as compared to plants at 30 microg P mL(-1). The highest ACO degradation (59%) was observed with AMF + SpCe. The phytoremediation of ACO was also enhanced by single inoculation of AMF or SpCe. The effect of AMF and petroleum-degrading microorganisms on plant growth and ACOdegradation was not

  12. Population distribution policies.

    PubMed

    Richardson, H W

    1983-01-01

    Population distribution policies have received increasing attention in recent years, especially in developing countries. One reason is that, especially in heavily primate developing countries, the spacial distribution of population (and economic activity) has generated conditions that conflict with important societal goals, such as interpersonal and interregional equity, national security, political stability, improvement in the quality of life, optimal resource exploitation, and long-term economic efficiency. Moreover, in many cases, the overall development strategy as reflected in macro and sectoral policies, has strong implicit spatial impacts that have, more often than not, reinforced an "unfavorable" population distribution, that is, one that conflicts with national goals and priorities. The only way to correct that is to modify the overall development strategy or to implement offsetting explicit population distribution policies. Many countries have adopted population distribution policies in recent years, but they have varied greatly in degree of implementation. Clear failures have been very common, and there have been almost no undiluted successes. This indifferent success should not be used as an argument against planned population distribution. The present article provides an overview of population distribution policies with special but not total reference to developing countries. Population goals are analyzed and the argument that rural-metropolitan migration is excessive is critically discussed. Policy instruments to influence the location of both households and firms are evaluated. It is argued that strategies to control primate city growth, to promote small towns and secondary cities and to implement rural-development programs are complementary rather than alternatives. Partial strategies, such as relocation of the national capital, countermagnets, new towns, border region policies and land colonization schemes, should be adopted only in rare cases

  13. Pharmacogenetics in Jewish populations

    PubMed Central

    Yang, Yao; Peter, Inga; Scott, Stuart A.

    2014-01-01

    Spanning over 2000 years, the Jewish population has a long history of migration, population bottlenecks, expansions, and geographical isolation, which has resulted in a unique genetic architecture among the Jewish people. As such, many Mendelian disease genes and founder mutations for autosomal recessive diseases have been discovered in several Jewish groups, which have prompted recent genomic studies in the Jewish population on common disease susceptibility and other complex traits. Although few studies on the genetic determinants of drug response variability have been reported in the Jewish population, a number of unique pharmacogenetic variants have been discovered that are more common in Jewish populations than in other major racial groups. Notable examples identified in the Ashkenazi Jewish (AJ) population include the vitamin K epoxide reductase complex subunit 1 (VKORC1) c.106G>T (p.D36Y) variant associated with high warfarin dosing requirements and the recently reported cytochrome P450 2C19 (CYP2C19) allele, CYP2C19*4B, that harbors both loss-of-function [*4 (c.1A>G)] and increased-function [*17 (c.−806C>T)] variants on the same haplotype. These data are encouraging in that like other ethnicities and subpopulations, the Jewish population likely harbors numerous pharmacogenetic variants that are uncommon or absent in other larger racial groups and ethnicities. In addition to unique variants, common multi-ethnic variants in key drug metabolism genes (e.g., ABCB1, CYP2C8, CYP2C9, CYP2C19, CYP2D6, NAT2) have also been detected in the AJ and other Jewish groups. This review aims to summarize the currently available pharmacogenetics literature and discuss future directions for related research with this unique population. PMID:24867283

  14. Population genetics and evolution

    SciTech Connect

    De Jong, G.

    1988-01-01

    This volume reevaluates the position of population genetics in evolutionary biology by using population genetics as the tool to study the role of development and adaptation in evolution. The emphasis is on the organismic process of selection, and on how the study of selection means connecting variation at the molecular, biochemical, and phenotypic levels of organization with the resulting variation in fitness. This book illustrates that the tendency to view single locus differences in isolation as the building blocks of evolution is disappearing.

  15. Population Density Modeling Tool

    DTIC Science & Technology

    2014-02-05

    of fatalities per loss. (2) where: POCA = Probability of Casualty (fatalities per loss) LCA = Lethal Crash Area of Aircraft (square...miles) Population Density = The average population density within the Potential Crash Area (PCA) (people per square miles) The LCA ...component in equation 2 has been previously calculated in the 3PRAT. The methodology used to determine the LCA is outlined in the report: Crash Lethality

  16. Can population grow forever?

    NASA Astrophysics Data System (ADS)

    Birch, P.

    1985-03-01

    Some theoretical calculations of the capacity of the universe to absorb an indefinitely increasing population of human beings are presented. It is proposed that by means of interstellar migration, the population, knowledge, and energy consumption of humans could increase forever. It is shown that although an open universe does not succumb to 'heat-death', the decay of very distant matter before mankind can reach it may present a problem.

  17. Mercury contamination in the vicinity of a chlor-alkali plant and potential risks to local population.

    PubMed

    Reis, Ana Teresa; Rodrigues, Sónia Morais; Araújo, Clarisse; Coelho, João Pedro; Pereira, Eduarda; Duarte, Armando C

    2009-04-01

    A mercury-cell chlor-alkali plant operated in Estarreja (North-western Portugal) for 50 years causing widespread environmental contamination. Although production by this process ceased in 2002, mercury contamination from the plant remains significant. The main objective of this study was to investigate mercury impact on the nearby environment and potential risks to local population. To assess the level of contamination soil samples were collected from agricultural fields in the vicinity of the plant, extending the study by taking samples of the predominant vegetation suitable for animal and human consumption, water samples, and fish species from a nearby coastal lagoon, to gain a preliminary insight into the potential for contamination of the terrestrial and aquatic food web. To determine population exposure to mercury, hair samples were collected from local residents. Total mercury concentration in the 0-15 cm layer of soil was found to be highly variable, ranging between 0.010 and 91 mg kg(-1), although mercury contamination of soils was found to be restricted to a confined area. Lolium perenne roots contained between 0.0070 and 2.0 mg kg(-1), and there is evidence that root systems uptake mercury from the soil. Levels of mercury in the aerial parts of plants ranged between 0.018 and 0.98 mg kg(-1). It appears that plants with higher mercury concentration in soils and roots also display higher mercury concentration in leaves. Total mercury concentration in water samples ranged between 12 and 846 ng L(-1), all samples presenting concentrations below the maximum level allowable for drinking water defined in the Portuguese law (1.0 microg L(-1)). Mercury levels in fish samples were below the maximum limit defined in the Portuguese law (0.5 mg kg(-1)), ranging from 0.0040 to 0.24 mg kg(-1). Vegetables collected presented maximum mercury concentration of 0.17 mg kg(-1). In general, food is not contaminated and should not be responsible for major human exposure to the

  18. Extinction of oscillating populations

    NASA Astrophysics Data System (ADS)

    Smith, Naftali R.; Meerson, Baruch

    2016-03-01

    Established populations often exhibit oscillations in their sizes that, in the deterministic theory, correspond to a limit cycle in the space of population sizes. If a population is isolated, the intrinsic stochasticity of elemental processes can ultimately bring it to extinction. Here we study extinction of oscillating populations in a stochastic version of the Rosenzweig-MacArthur predator-prey model. To this end we develop a WKB (Wentzel, Kramers and Brillouin) approximation to the master equation, employing the characteristic population size as the large parameter. Similar WKB theories have been developed previously in the context of population extinction from an attracting multipopulation fixed point. We evaluate the extinction rates and find the most probable paths to extinction from the limit cycle by applying Floquet theory to the dynamics of an effective four-dimensional WKB Hamiltonian. We show that the entropic barriers to extinction change in a nonanalytic way as the system passes through the Hopf bifurcation. We also study the subleading pre-exponential factors of the WKB approximation.

  19. [Population and food scarcity].

    PubMed

    Castro, E S

    1995-07-01

    Rapid population growth and increasing industrialization threaten to exhaust the world's natural resources, while the air, water, and soil are contaminated by wastes. Efforts to modify processes endangering man's survival are merely local palliatives. World population increased by 2 billion in the past 10 years. El Salvador's population is growing at 2% annually and now exceeds 5 million. These facts are well known, but the average person does not feel personally affected by them, trusting in scientific and technological progress to solve problems. The reality is that 2/3 of the world's people are vulnerable to hunger. Technological advances in agriculture have been outpaced by rapid population growth. Droughts and other climatic disturbances lead to hunger, and lost harvests constitute calamities. El Salvador's ecological situation is critical, with widespread degradation of agricultural lands. Thousands of hectares are lost each year. The high cost of basic foods is due to the collapse of agricultural production, itself a result of poor planning. El Salvador has become an importer of many essential foodstuffs. Experts have predicted that rapid population growth will soon mean that the country is no longer able to produce all the food it needs. Campaigns for responsible parenthood are needed to slow population growth. Couples should decide how many children to have based on their ability to support and educate them. The government should adopt a realistic position and encourage responsible parenthood, with free medical advice and family planning services for those desiring to avoid pregnancy.

  20. Population growth and consumption.

    PubMed

    Chalkley, K

    1997-04-01

    The relationship between population growth, resource consumption, and environmental degradation is complex. The rise in "greenhouse gases" that will cause climatic change is clearly due to human activity, and pollutants are often concentrated in densely populated areas. However, even an area with a negative population growth, such as Russia, can experience severe environmental degradation due to poor management. Consumption patterns have the most effect on ozone depletion, while population growth threatens biodiversity of and within species through the destruction of ecosystems. Migration joins population growth and social factors, such as land inequality, as major causes of deforestation, and global demand for water is expected to increase faster than the rate of population growth. Coastal development and over-fishing threaten to deplete the oceans, while soil quality is threatened by inappropriate land use. Estimates of the earth's carrying capacity range from less than 3 billion to more than 44 billion people, indicating how difficult it is to assess this figure. Development efforts throughout the world may lead to human gains that will ultimately be negated by environmental losses. These factors have led to growing support for environmentally sustainable development.

  1. Mexican population: 1982.

    PubMed

    Sanders, T G

    1982-01-01

    In 1940, Mexico had less than 30% of its 1980 population of 69,346,900. The annual rate of growth by decades accelerated from 1.72% in 1930-40, to 2.72% in 1940-50, to 3.13% in 1950-60, and to 3.43% in 1960-70. Infant mortality has declined from 124.5/1000 in 1940 to 56.8/1000 in 1980, while general mortality has declined from 26.6/1000 in 1930 to 7.5/1000 in 1980. Average life expectancies of men and women respectively have increased from 40.39 and 42.50 in 1940 to 62.3 and 66.1 in 1980 and are expected to continue a slow rise. Mortality, infant mortality, and average life expectancy figures are least favorable in the poorest and least developed areas. Political opposition is believed to be 1 main reason for Mexico's late adoption of a population control program, but since the family planning program was established it has enjoyed solid government support. Mexico's rate of population growth appeared to peak at about 3.5% in 1975; it was estimated at 2.7% by the 1980 census and may have declined to 2.5% in 1982. By 1979 all age groups of women were having fewer children, with those aged 20-34 achieving the most significant drop. Fertility differentials by rural and urban residence, size of place and women's education are marked. The government's goal is to reduce the rate of population increase to 1%/year by the year 2000, with a population of 100,041,400. Because of the unfavorable age structure resulting from past rapid growth, that goal will be difficult to achieve. The most realistic of 3 National Population Council population projections envisions a rate of increase of 2% annually and a population of 106,570,400 in 2000. The pattern of city growth from 1970-80 indicates that Mexico is having some success in decentralizing economic growth and urban population concentration, but the largest cities continued to grow substantially. About 39.31% of workers are in agriculture, 13.17% are in services and transport, 22.47% are in other areas, 8.14% are vendors, and

  2. Population and development.

    PubMed

    1987-03-01

    The Economic and Social Commission for Asia and the Pacific (ESCAP) recently organized a workshop to develop an analytical framework for population research and development planning. The workshop goal was to enable study directors to review and discuss research methodology and guidelines for a series of country studies to be undertaken as part of a large project devoted to integrating population and development. The overall project objective is to provide individual national entities with current and scientifically sound descriptions, analyses, and interpretations of significant population and development trends and their interrelationships along with assessments of the implications of such trends and relationships for the formulation and improvement of public policy. 1 reason for the limited progress in the integration of population and development planning is the lack of useful and applicable scientific information for responsible planners as well as a lack of analytical frameworks. If the results of the research are to be made useful for decisionmaking purposes, processing of the information is required. The need exists for current critical analysis and synthesis of available information at the country level on significant population and development trends and their interrelationships and an assessment of their implications for the formulation and improvement of public policy and programs. In regard to an analytical framework, much work has been done in the areas of population development interrelationships and their modelling. Bangladesh, Nepal, the Philippines, and Thailand are the countries which have been selected for investigation for the ESCAP project. The comparative analysis that is to be conducted will facilitate understanding of current population development research activities and the future needs of these countries.

  3. World population perspectives 1985.

    PubMed

    Loraine, J A

    1985-01-01

    Some progress has been made in curbing global population growth, yet much remains to be done, particularly in 3rd world countries. Population growth reached its zenith between 1950-70. The growth rate then remained at 2% per annum. By the early 1970s, the pace began to slow, and by 1985 it was down to 1.7%. UN sources anticipate a further drop to 1.5% by 2000. The decline has been due primarily to falling birthrates in some developing nations. China with its 1-child policy has been responsible for a major effect, but also there have been notable declines in other Asian and in Latin American countries. One important factor is the inherent dynamic of the population process. The momentum of population growth is remarkable; world numbers are destined to increase for decade upon decade. Fertility levels and overall rates of population growth will determine when different regions of the world are likely to realize stability . Regarding the level at which the world population will stabilize eventually, the figures most commonly quoted by international agencies range from 8000-10,000 million. This total would strain the earth's carrying capacity to an unacceptable degree and produce ecological malpraxis. In 1985 the developed nations accounted for about 1/4 of the world's population. The rate of growth had been slow for over 20 years and currently is 0.6% per annum. The 2 major demographic changes in the area are continuing low birthrates and a marked rise in the relative and absolute numbers of elderly people. In 1985 the less developed world of Africa, Asia, and Latin America housed 3700 million people, about 3/4 of the world's total. During the next 15 years, 85% of the births are expected to occur in the less developed world. Developing countries show great variations with respect to such demographic indices as birthrates, death rates, and infant mortality rates, but they share with developed nations the marked increase in their numbers of old people. This trend is

  4. China. Population. New threat.

    PubMed

    Although China's population growth rate in 1980 was the lowest in 31 years, doubling of marriages and increasing life expectancy have emerged as threats to the government plan to hold national population growth to 1200 million by the end of the present century, a Beijing official magazine reported. Liaowang (Observation), published by the government's Xinhua news agency, quoted state family planning officials as saying that a subsequent doubling of marriages this year "threatens another baby boom in the world's most populous nation." The officials said the country's population stood at 982.55 million at the end of 1980, roughly equivalent to 20% of the world's total. According to the magazine, the natural population growth rate declined to 8.97 million last year as the number of births fell to 14.99 million and that of deaths stood at 6.02 million. During the past decade, the natural increase rate of China's population dropped from 26/1000 in 1970 to just 12/1000 in 1980. Owing to increase in production and living standards, along with expansion and improvement of medical facilities, the mortality rate fell from almost 30/1000 before the founding of the People's Republic of China to around 6-8/1000 by the 1970s. According to U.N. statistics prepared for the recently-held international conference on population and development in Beijing, China succeeded in reducing its birth rate by as much as 23.1% between 1960-65 and 1970-75. But such accomplishment is now in danger of being wiped out by a new birth peak expected during the next 10 or more years as those born during the baby boom of the 1960s reached childbearing age during the present decade. In addition, the population control program is also threatened by the rising life expectancy of the Chinese people. Latest statistics compiled by the Ministry of Public Health showed that the average life span of the Chinese population had doubled to 68 years in 1980 from 35 years in 1949. full text

  5. Alternative population futures.

    PubMed

    1980-01-01

    The Philippines is now passing through a late demographic transitional period in which the death rate declines while the birth rate remains at a relatively high level; the population of young people under 15 rises to about 45% of the population while proportions of people of working age and old people decline. In 1970, 4 of the Philippine's 12 regions had a birth rate exceeding 40/1000; life expectancy at birth in these regions ranged from 57-64 years and population growth rates ranged from 2.6-4.2% annually. Also in 1970 40-49% of all 12 regional populations were young (under 15) and only 2-5% were old. In this transitional period there are a greater number of children in each household and thus heavier social and economic burdens occur; also the burden of youth dependency increases by more than 1/3. In the modern population structure, family burdens diminish as the average number of children surviving to age 20 becomes identical with the number of children born and great improvements in the quality of life are allowed. Population projections are based on the following assumptions: 1) decrease in mortality, either rapid or slow, 2) increase in age at marriage, 3) decline in fertility will remain at 0.7% annually, and 4) migration trends will stay the same as during the 1960-75 period. Total population is expected to reach 83.8 million by 2000, a 98% increase from 1975; a low estimate, assuming lower fertility and nuptiality, is 64.1 million, a 52% increase from 1975. The urban population will more than double its size by the year 2000 and rural population will grow from 22-65% with the fastest urbanizing regions being the Central and Southern Luzon. From 1975-2000 a 3-fold increase is expected in the number of families in Metro Manila. By 2000 a national labor force of 27.5 million is expected, more than double the 1970 level, with late entry into the labor force and declines in participation by elderly males. The various regions will see lower economic activity

  6. Marketing and population problems.

    PubMed

    Farley, J U; Leavitt, H J

    1971-07-01

    There are many elements in population programs that are more familiar to marketing men than to some population experts. Advertising is essential to reach the target population, and advertising evaluation techniques (e.g., surrogate indexes or audience measures) might be useful for evaluating both population information activities and the import of the entire program. Fundamental research on basid demand for fertility control is needed and a marketer's experience with planning and evaluating test markets can be useful in assessing potential selling targets and evaluating alternative promotional and distributional strategies. Special family planning clinics have certain disadvantages: expensive and scarce personnel are needed; red tape may be present; the network is based on the assumption that the client is willing to travel relatively great distances repeatedly; and clinics lack anonymity which may scare potential acceptors away. Most developing cultures have an intensively functioning distribution structure which delivers basic commodities to the most remote areas, providing relatively anonymous outlets that are physically close to the customs. Materials requiring a prescription might be distributed in exchange for script issued at and ultimately redeemed by clinics, this requiring only an occasional visit to a clinic. Mail-order service can be used to supplement a clinic's distribution of some contraceptives. It should be remembered that population administrators often have an antipathetic view toward business and marketing and "suspect" the profit motive.

  7. Population pressure rising.

    PubMed

    1994-08-01

    Even though the ESCAP region has been successful in slowing population growth, Asia will account for half of the global population increase every year, or about 1 billion persons in the next quarter century, according to a new report by the Asian Development Bank (ADB). That report, entitled "Population Policy Paper," states that Asia will be the global center of population aging largely because of big increases in the number of persons over the age of 65 in China, Japan and the region's newly industrializing economies. "By the year 2000, 86% of the world's aged will be in the Asia-Pacific region and by the year 2025 there are projected to be 687 million persons over the age of 65 in the region, placing unprecedented strains on economic and social systems far beyond what traditional extended family networks can absorb," the paper says. But the report also considers other aspects of overall population increase. "The prospect of an additional billion or so people in Asia over the next 25 years is daunting, since the implications for poverty, economic growth, unemployment and environmental quality are immense," it adds. The region's economies will have to scramble to generate jobs and livelihoods for tens of millions of young people for the next several decades. Rural-to-urban migration trends threaten the collapse of urban infrastructure, with the social tensions and political instability that such troubles bring, the report states.

  8. Extinction in population dynamics

    NASA Astrophysics Data System (ADS)

    Escudero, C.; Buceta, J.; de La Rubia, F. J.; Lindenberg, Katja

    2004-02-01

    We study a generic reaction-diffusion model for single-species population dynamics that includes reproduction, death, and competition. The population is assumed to be confined in a refuge beyond which conditions are so harsh that they lead to certain extinction. Standard continuum mean field models in one dimension yield a critical refuge length Lc such that a population in a refuge larger than this is assured survival. Herein we extend the model to take into account the discreteness and finiteness of the population, which leads us to a stochastic description. We present a particular critical criterion for likely extinction, namely, that the standard deviation of the population be equal to the mean. According to this criterion, we find that while survival can no longer be guaranteed for any refuge size, for sufficiently weak competition one can make the refuge large enough (certainly larger than Lc) to cause extinction to be unlikely. However, beyond a certain value of the competition rate parameter it is no longer possible to escape a likelihood of extinction even in an infinite refuge. These unavoidable fluctuations therefore have a severe impact on refuge design issues.

  9. Thermodynamics and Human Population

    NASA Astrophysics Data System (ADS)

    Cordry, Sean M.

    2010-09-01

    This paper discusses a Fermi-problem exercise through which I take students in several of my college courses. Students work in teams, determining the average daily Caloric needs per person. Then they use insolation values to determine the size of a collection area needed to absorb the previously determined daily energy requirements. Adjustments to the size of the collection area are made based on energy absorption per biological trophic level, as well as the consideration that most diets are a mixture of plant- and animal-derived elements. Finally, using the total amount of farmland available on the planet, students calculate a maximum population value. Although the maximum population values derived herewith should not be considered authoritative, the exercise has three beneficial purposes: 1) a chance to talk about the modeling process and extrapolations, 2) an unexpected application of physics to social contexts, and 3) raising student awareness of population and energy issues.

  10. National population policy.

    PubMed

    Singh, K

    1976-01-01

    Dr. Singh emphasized that the Indian government realized radical measures were necessary to control the country's staggering population explosion. With only 2.4% of the world's area, it has 15% of the world's population, increasing at a rate of over 1 million/month. Suggested measures include raising the age of marriage, freezing state representation until 2001 to increase the states' interest in population problems, increasing female literacy, increasing monetary compensation for voluntary sterilization, providing group incentives, using voluntary organizations, and generally changing the urban elitist approach of the past into more imaginative rural-oriented attitudes. States with adequate facilities could institute compulsory sterilization after 3 children, uniformly applicable to state citizens.

  11. Population options for Australia.

    PubMed

    Ruddock, P

    1999-01-01

    In an address to the Australian Population Association Biennial Conference during October 1998, the Immigration and Multicultural Affairs Minister Philip Ruddock argued that neither the zero net overseas migration policy nor the massive boost in immigration are in the national interest of Australia. Environmental groups generally view that Australia should adopt a policy of zero net overseas migration. On the other hand, business and industry bodies consider that a substantial increase in the migration intake is needed in order to increase economic growth and to reduce the impact of an aging population. Moreover, some are concerned about population targets reaching up to 50 million in 50 years time. Thus, management of immigration policy is a difficult balancing act between competing objectives. The Minister concluded that their immigration program must operate on a totally global and nondiscriminatory basis regarding matters such as race, religion, color, and ethnic origin.

  12. Population and Climate Change

    NASA Astrophysics Data System (ADS)

    O'Neill, Brian C.; Landis MacKellar, F.; Lutz, Wolfgang

    2000-11-01

    Population and Climate Change provides the first systematic in-depth treatment of links between two major themes of the 21st century: population growth (and associated demographic trends such as aging) and climate change. It is written by a multidisciplinary team of authors from the International Institute for Applied Systems Analysis who integrate both natural science and social science perspectives in a way that is comprehensible to members of both communities. The book will be of primary interest to researchers in the fields of climate change, demography, and economics. It will also be useful to policy-makers and NGOs dealing with issues of population dynamics and climate change, and to teachers and students in courses such as environmental studies, demography, climatology, economics, earth systems science, and international relations.

  13. [Population problem, comprehension problem].

    PubMed

    Tallon, F

    1993-08-01

    Overpopulation of developing countries in general, and Rwanda in particular, is not just their problem but a problem for developed countries as well. Rapid population growth is a key factor in the increase of poverty in sub-Saharan Africa. Population growth outstrips food production. Africa receives more and more foreign food, economic, and family planning aid each year. The Government of Rwanda encourages reduced population growth. Some people criticize it, but this criticism results in mortality and suffering. One must combat this ignorance, but attitudes change slowly. Some of these same people find the government's acceptance of family planning an invasion of their privacy. Others complain that rich countries do not have campaigns to reduce births, so why should Rwanda do so? The rate of schooling does not increase in Africa, even though the number of children in school increases, because of rapid population growth. Education is key to improvements in Africa's socioeconomic growth. Thus, Africa, is underpopulated in terms of potentiality but overpopulated in terms of reality, current conditions, and possibilities of overexploitation. Africa needs to invest in human resources. Families need to save, and to so, they must refrain from having many children. Africa should resist the temptation to waste, as rich countries do, and denounce it. Africa needs to become more independent of these countries, but structural adjustment plans, growing debt, and rapid population growth limit national independence. Food aid is a means for developed countries to dominate developing countries. Modernization through foreign aid has had some positive effects on developing countries (e.g., improved hygiene, mortality reduction), but these also sparked rapid population growth. Rwandan society is no longer traditional, but it is also not yet modern. A change in mentality to fewer births, better quality of life for living infants, better education, and less burden for women must occur

  14. National population policy.

    PubMed

    1983-01-26

    India evolved a comprehensive national population policy in April 1967. The primary assumption behind this policy was that the population explosion was an offshoot of poverty and must be dealt with as a part of an overall design for a better life. Clear demographic goals were defined, and several programs were initiated as part of the policy in an effort to integrate family planning with the overall strategy of socioeconomic development. The following are among the more important features of the 1976 national population policy: 1) increase the marriage age from 15-18 years for girls and from 18 to 21 years for boys; 2) freeze the population figures at the 1971 level until the year 2001 for purposes of representation in the national parliament as well as for allocation of central assistance, devolution of taxes, and so forth to the States; 3) more attention to the education of girls; 4) a proper place for population education in the total system of education; 5) involvement of all ministries/departments of government in the family planning program; 6) increase in monetary compensation for sterilization; 7) institution of group awards as incentives for various organizations and bodies representing the people at local levels; 8) the intimate association of voluntary organizations with the implementation of the program; 9) more attention to research; and 10) greater use of motivational media, particularly in rural areas, for increasing acceptance of family planning. According to Indira Gandhi, the objective is not simply to curb population growth but to have happier and healthier families, which, in India's circumstances, means smaller families. In the 1st 5-year plan (1951-56) India's outlay on family planning (Rs. in crores) was 0.65. It had increased to 1010.00 by the 6th 5-year plan (1980-85).

  15. Population and development.

    PubMed

    Pavlik, Z

    1995-01-01

    During the Paleolithic period, 10,000-100,000 people lived on the earth; their number exceeded 1 million at the beginning of the Neolithic period, reached 10 million during the Bronze Age, 100 million at the beginning of the Iron Age, 1 billion at the beginning of the 19th century, and 5.7 billion in 1995. The estimated global population will be 10 billion by the middle of the 21st century and is expected to stabilize at around 10-12 billion subsequently. Increased agricultural production helped bring about greater numbers of humanity and the advancement of society with a developing social hierarchy, although life expectancy was low at 22-28 years. In Europe, the Renaissance gradually evolved into the Industrial Revolution, and a demographic revolution accompanied this process. In some countries, population size increased more than five times. Eventually, mortality and fertility levels decreased and life expectancy increased. In Western civilization, increased individualism, secularization, compulsory school attendance, decreased agricultural population, emancipation of women, increased costs of raising children, and social and economic progress ensued. All this was preceded by 18th century conditions, when, in England, capital accumulation led to wealth on the one side and destitution on the other, giving rise to Malthus's famous theory. However, during the 19th century these social inequalities gradually evened out. After World War II, the question arose of whether the populations of other civilizations (Confucian, Japanese, Islamic, Hindu, Slavic-Orthodox, Latin American, and African) would also undergo a demographic transition and how soon. At any rate, developed country population size, as a percentage of global population, will drop from 22% to 13%, and that of Africa will increase from 12% to 26%, during the 21st century.

  16. Distance Learning for Special Populations

    ERIC Educational Resources Information Center

    Bates, Rodger A.

    2012-01-01

    Distance education strategies for remotely deployed, highly mobile, or institutionalized populations are reviewed and critiqued. Specifically, asynchronous, offline responses for special military units, Native Americans on remote reservations, prison populations and other geographically, temporally or technologically isolated niche populations are…

  17. Distance Learning for Special Populations

    ERIC Educational Resources Information Center

    Bates, Rodger A.

    2012-01-01

    Distance education strategies for remotely deployed, highly mobile, or institutionalized populations are reviewed and critiqued. Specifically, asynchronous, offline responses for special military units, Native Americans on remote reservations, prison populations and other geographically, temporally or technologically isolated niche populations are…

  18. World Population: Facts in Focus. World Population Data Sheet Workbook. Population Learning Series.

    ERIC Educational Resources Information Center

    Crews, Kimberly A.

    This workbook teaches population analysis using world population statistics. To complete the four student activity sheets, the students refer to the included "1988 World Population Data Sheet" which lists nations' statistical data that includes population totals, projected population, birth and death rates, fertility levels, and the…

  19. Fitness in Special Populations.

    ERIC Educational Resources Information Center

    Shephard, Roy J.

    This book examines fitness research among special populations, including research on fitness assessment, programming, and performance for persons with various forms of physical disabilities. The book covers such topics as diseases that complicate life in a wheelchair, disability classifications, physiological responses to training, positive…

  20. [Population and development].

    PubMed

    Trias, M

    1987-01-01

    Human reproduction and development are contrasted; they are intimately linked despite the fact that they may be considered antitheses of each other from many points of view. Presently technological development and the advance of humans into every available corner of living space threaten to place the whole world environment in danger. The Green revolution of the 1960s addressed problems of underproduction of food for the world's population, without providing for the effective distribution of the new surpluses, and without addressing the problem of the ecological impact. 2 trends which are regarded by some with alarm: the migration of populations to the cities and the aging of the population with the connected burden on health care systems, are inevitable, and it is not clear that they are completely negative trends. Addressing these issues will have positive effects in the long run: congestion in the cities, the result of mechanization of rural industry which also results in a greater abundance of agricultural products necessary to society, should force serious consideration of problems such as solid waste management. Coming to terms with the costs of intervention to save lives among the very frail elderly and the prematurely born will have the effect of bringing controversial topics such as euthenasia and eugenics to discussion. The important role played by economic development in the braking of population expansion is underlined.

  1. Introduction to Population Modeling.

    ERIC Educational Resources Information Center

    Frauenthal, James C.

    The focus is on the formulation and solution of mathematical models with the idea of a population employed mainly as a pedogogical tool. If the biological setting is stripped away, the material can be interpreted as topics or the qualitative behavior of differential and difference equations. The first group of models investigate the dynamics of a…

  2. Fitness in Special Populations.

    ERIC Educational Resources Information Center

    Shephard, Roy J.

    This book examines fitness research among special populations, including research on fitness assessment, programming, and performance for persons with various forms of physical disabilities. The book covers such topics as diseases that complicate life in a wheelchair, disability classifications, physiological responses to training, positive…

  3. Population and Development Issues.

    ERIC Educational Resources Information Center

    Cohen, Sharon; Garran, Christopher

    1998-01-01

    Describes a unit on demographics for a high school world-history course that addresses questions of uneven population growth and the "problem of global overpopulation." Provides a detailed outline of the two-day unit including unit and daily goals and objectives, daily activities and questions, and ideas for further student research. (DSK)

  4. Population: fiction and fact.

    PubMed

    1979-09-01

    This article was written to refute some common misunderstandings regarding worldwide population levels and worldwide nutrition levels. The world food supply is able to keep pace with high population growth levels. Worl food production currently meets world need; the problem is a distribution system which allocates food only to those who can pay rather than to those who need it. In many developing countries, the best agricultural lands are reserved for commercial crops rather than for subsistence crops. The U.S. food aid program does not help the most needy nations generally. The rate of world population growth is already slowing down. The desire for large families in developing countries is very often a realistic reaction to the prevailing economic system. Family planning programs will succeed. They will succeed even better in countries where general development planning is undertaken concurrently with family planning. Environmental problems are attributable to the consumption explosion in the rich countries rather than to the population explosion in the poor countries.

  5. Puppets and Population.

    ERIC Educational Resources Information Center

    Baird, Bil

    This document focuses on the use of puppets for educating the illiterate populations of the world in food production and family planning. It is presented as one practical and effective tool for the adult educator and literacy worker. When used as part of a total program of functional literacy for family life planning, it can help young adults gain…

  6. Mentoring Special Youth Populations

    ERIC Educational Resources Information Center

    Britner, Preston A.; Balcazar, Fabricio E.; Blechman, Elaine A.; Blinn-Pike, Lynn; Larose, Simon

    2006-01-01

    Whereas mentoring programs are well received as support services, very little empirical research has been conducted to assess the effectiveness of these programs to meet the diverse needs of different special populations of youth. Potentially useful theoretical orientations (attachment, parental acceptance-rejection, social support, adult…

  7. Population and Development Issues.

    ERIC Educational Resources Information Center

    Cohen, Sharon; Garran, Christopher

    1998-01-01

    Describes a unit on demographics for a high school world-history course that addresses questions of uneven population growth and the "problem of global overpopulation." Provides a detailed outline of the two-day unit including unit and daily goals and objectives, daily activities and questions, and ideas for further student research. (DSK)

  8. Reconstructing Druze population history

    PubMed Central

    Marshall, Scarlett; Das, Ranajit; Pirooznia, Mehdi; Elhaik, Eran

    2016-01-01

    The Druze are an aggregate of communities in the Levant and Near East living almost exclusively in the mountains of Syria, Lebanon and Israel whose ~1000 year old religion formally opposes mixed marriages and conversions. Despite increasing interest in genetics of the population structure of the Druze, their population history remains unknown. We investigated the genetic relationships between Israeli Druze and both modern and ancient populations. We evaluated our findings in light of three hypotheses purporting to explain Druze history that posit Arabian, Persian or mixed Near Eastern-Levantine roots. The biogeographical analysis localised proto-Druze to the mountainous regions of southeastern Turkey, northern Iraq and southeast Syria and their descendants clustered along a trajectory between these two regions. The mixed Near Eastern–Middle Eastern localisation of the Druze, shown using both modern and ancient DNA data, is distinct from that of neighbouring Syrians, Palestinians and most of the Lebanese, who exhibit a high affinity to the Levant. Druze biogeographic affinity, migration patterns, time of emergence and genetic similarity to Near Eastern populations are highly suggestive of Armenian-Turkish ancestries for the proto-Druze. PMID:27848937

  9. [Population trends and poverty].

    PubMed

    Olmedo, C

    1998-04-01

    Implications of population growth in Ecuador for the quality of life of the poor population are analyzed. It is argued that if the gross national product (GNP) were to grow at a sustained annual rate of 5% or more, demographic trends would not present a significant obstacle to reducing poverty. National economic projections are for growth of only 2.5-3.5% annually. The continuing rapid growth of the poor population despite general slowing of demographic growth, the young age structure, the need for increased formal education to enable the poor to overcome their poverty, and the effect of unemployment on the dependency ratio will tend to hamper improvements in average productivity and per capita GNP. The need for spending on education, health, basic services, and housing will divert funds away from productive investment, generating a direct negative impact on economic growth. Over half of Ecuadorian children suffer from some degree of malnutrition, indicating that food production is inadequate to meet demand. The export-oriented agricultural policy and poor weather have led to a chronic shortage of basic foods. Progressive increase and diversification of agricultural production, along with maintenance of low prices and substantial increases in income levels and agricultural productivity, will be required if the entire population is to be fed adequately. Intense efforts will be needed from all sectors to bring demographic growth into balance with economic and development needs.

  10. Relics: penguin population programs.

    PubMed

    Sun, L; Xie, Z

    2001-01-01

    What has been responsible for the increase in Chinstrap penguin populations during the past 40 years in maritime Antarctica? One view ascribes it to an increase in availability of their prey brought on by the decrease in baleen whale stocks. The contrary opinion, attributes it to environmental warming. This causes a gradual decrease in the frequency of cold years with extensive winter sea ice cover. A number of penguin monitoring programs are in progress and are expected to provide some answers to these questions. Unfortunately, it is not easy to distinguish natural variability from anthropogenic change since penguins are easily accessible predators of krill and the feeding range of the penguins has almost overlapped with the krill fishery in time and space in the last four decades. Therefore it is important to reconstruct the change of ancient penguin abundance and distribution in the absence of human activity. Many efforts have focused on surveying the abandoned penguin rookeries, but this method has not been able to give a continuous historical record of penguin populations. In several recent studies, ancient penguin excreta was scooped from the penguin relics in the sediments of the lake on penguin rookery, Ardley Island, maritime Antarctica. In these studies, penguin droppings or guano soil deposited in the lake and changes in sediment geochemistry have been used to calculate penguin population changes based upon the geochemical composition of the sediment core. The results suggest that climate change has a significant impact on penguin populations.

  11. Probabilistic population aging

    PubMed Central

    2017-01-01

    We merge two methodologies, prospective measures of population aging and probabilistic population forecasts. We compare the speed of change and variability in forecasts of the old age dependency ratio and the prospective old age dependency ratio as well as the same comparison for the median age and the prospective median age. While conventional measures of population aging are computed on the basis of the number of years people have already lived, prospective measures are computed also taking account of the expected number of years they have left to live. Those remaining life expectancies change over time and differ from place to place. We compare the probabilistic distributions of the conventional and prospective measures using examples from China, Germany, Iran, and the United States. The changes over time and the variability of the prospective indicators are smaller than those that are observed in the conventional ones. A wide variety of new results emerge from the combination of methodologies. For example, for Germany, Iran, and the United States the likelihood that the prospective median age of the population in 2098 will be lower than it is today is close to 100 percent. PMID:28636675

  12. Highways and Population Change

    ERIC Educational Resources Information Center

    Voss, Paul R.; Chi, Guangqing

    2006-01-01

    In this paper we return to an issue often discussed in the literature regarding the relationship between highway expansion and population change. Typically it simply is assumed that this relationship is well established and understood. We argue, following a thorough review of the relevant literature, that the notion that highway expansion leads to…

  13. Adam Smith on population.

    PubMed

    Spengler, J J

    1970-11-01

    Abstract Adam Smith dealt with questions of population mainly in his Wealth of Nations. His discussion falls roughly under five heads and reflects in considerable measure his image of the English economy. (1) A country's population capacity, given the average level of consumption, was conditioned by the stock of land, the skill with which it was cultivated, and the degree to which division of labour could be increased and thereby augment output for domestic use and sale in external markets. (2) Growth of population was essentially in response to growth of the demand for labour and served to increase division of labour. (3) The social mechanisms underlying elevation of the scale of living are touched upon, and in an optimistic spirit. (4) The distribution of a country's population responded to its progress in opulence, with the rate of this progress conditioned by the degree to which inappropriate (e.g. mercantilist) policies were avoided. (5) Smith dealt briefly with such matters as colonies, education, size of economy, environmental influences, and public policy, all of which he recognized as significant for the quantity and quality of a country's numbers.

  14. Highways and Population Change

    ERIC Educational Resources Information Center

    Voss, Paul R.; Chi, Guangqing

    2006-01-01

    In this paper we return to an issue often discussed in the literature regarding the relationship between highway expansion and population change. Typically it simply is assumed that this relationship is well established and understood. We argue, following a thorough review of the relevant literature, that the notion that highway expansion leads to…

  15. The population problem?

    PubMed

    Mcelroy, W

    1968-01-01

    Most governments that have considered the population problem have been doing a part time job, working to stabilize the population by spreading knowledge of oral contraception (OC) and other contraceptive devices. An inadequate job is being done in promoting the reduction of the birthrate. What is needed is an all out effort from all countries concerned. It was only in 1965 that a President of the US for the 1st time made a positive statement about the government's position and support for family planning programs. Until then all government agencies were careful to avoid discussing this matter in opening meetings. Thereafter, President Johnson repeatedly indicated that he recognized the seriousness of the problem and the need for intelligent and direct action. Yet, the appropriation and distribution of funds for population control in the US and developing countries has failed to keep pace with the superlative statements made by national and responsible individuals on the importance of the problem. Family planning is more than a program just for the distribution of contraceptive devices. Where knowledgeable personnel are available, they try to identify the broad social problems resulting from large familles. They try to influence the behavior of the individual couples with regard to family size. Yet, even in the US the number of personnel is inadequate to carry out this large educational program. The Committee on Population of the National Academy of Sciences stressed several points: a zero rate of population growth may prove essential in the long run but as a goal within the time horizon of present policy it has little support in either the developed or developing countries, certainly not among governments; a need exists for exploration of a broader range of measures for their potential contribution to the easing of population pressures, particularly in the developing countries where rapid population growth is particularly threatening; programs of social change need

  16. Population and women's health.

    PubMed

    Abernethy, V

    1994-01-01

    Explanations of cultural patterns can be found in the economic context (carrying capacity) in which they develop. Population pressure explains the abuse of women throughout history and in modern times because overpopulation leads to devaluation of women's reproductive capacity. A cultural response to overpopulation includes practices that limit the numbers of women of reproductive age. Such practices foster son preference, which results in selective abortion, female infanticide, neglect and overwork of girls, dowry deaths, and discrimination against widows. The results of these practices are manifest in sex ratios that are culturally rather than naturally controlled and in demographic facts such as the calculation that 60 million females are missing in Asia alone (and perhaps more than 100 million worldwide). Women are also removed from a reproductive setting by being kidnapped or sold into prostitution or by being forced to adopt prostitution for economic survival. In cases where survival is threatened by environmental degradation and population growth, the most harsh cultural practices will emerge to adapt the population to the resources at hand. This situation creates an ethical dilemma posed by the problem of imposing Western values on a culture that is undertaking adaptive practices to insure its very survival. Ways to help women in these situation include limiting population growth humanely through family planning, provision of paid work to women, and creation of an environment that supports a small family ideal. Prosperity itself, through modernization, sometimes causes family sizes to increase. The most important intervention appears to be the provision of paid employment outside the home for women. On the other hand, large-scale wealth transfers and liberal immigration policies simply send signals that population pressure is a regional problem that can be alleviated by the international community. Increasing immigration to developed countries will place

  17. Secondary Globular Cluster populations

    NASA Astrophysics Data System (ADS)

    Fritze-v. Alvensleben, U.

    2004-02-01

    This study is motivated by two facts: 1. The formation of populous star cluster systems is widely observed to accompany violent star formation episodes in gas-rich galaxies as e.g. those triggered by strong interactions or merging. 2. The Globular Cluster (GC) systems of most but not all early-type galaxies show bimodal optical color distributions with fairly universal blue peaks and somewhat variable red peak colors, yet their Luminosity Functions (LFs) look like simple Gaussians with apparently universal turn-over magnitudes that are used for distance measurements and the determination of Ho. Based on a new set of evolutionary synthesis models for Simple (= single burst) Stellar Populations (SSPs) of various metallicities using the latest Padova isochrones I study the color and luminosity evolution of GC populations over the wavelength range from U through K, providing an extensive grid of models for comparison with observations. I assume the intrinsic widths of the color distributions and LFs to be constant in time at the values observed today for the Milky Way or M 31 halo GC populations. Taking the color distributions and LFs of the Milky Way or M 31 halo GC population as a reference for old metal-poor GC populations in general, I study for which combinations of age and metallicity a secondary GC population formed in some violent star formation event in the history of its parent galaxy may or may not be detected in the observed GC color distributions. I also investigate the effect of these secondary GCs on the LFs of the total GC system. Significant differences are found among the diagnostic efficiencies in various wavelength regions. In particular, we predict the NIR to be able to reveal the presence of GC subpopulations with different age - metallicity combinations that may perfectly hide within one inconspicuous optical color peak. If the entire manifold of possible age - metallicity combinations is admitted for a secondary GC population, we find several

  18. The population dilemma.

    PubMed

    Kunugi, T

    1990-06-01

    Technology and population rely on each other for sustenance and growth. Technology has helped produce more food, provide better health care, better communication, faster modes of travel, better consumer durables, greater amenities, and increased the quality of life for millions of people. There has been a price in terms of the widening gap between the technology of the developed and developing countries. There has also been rapid population growth that has resulted in a host of ills. Further, technology itself has produced toxic wastes and consumed a large amount of natural resources. This situation is easily seen as a dilemma between the limitless promises of technology and the limited resources created by large populations. The solution to the dilemma is sustainable development, a concept often talked about but seldom realized. The 90s will be a crucial decade for sustainable development as population is growing by 90 million/annum. 90% of the increase is occurring in developing countries. Within each country there is a trend towards urbanization. By 2000, 75% of Latin Americans, 42% of Africans, and 37% of Asians will live in urban environments. By 2050 there should be 100s of millions of migrants running from the slowly rising sea. The survival equation is sustainability S equals resources R time ingenuity 1 over population P. This is a conceptual equation, but it does illustrate that the impact of human ingenuity is just as important as resources. World commitment must come before any meaningful change will occur. The almost universal acceptance of human rights and fundamental freedoms exceeds the will to change in decision makers and expert consultants.

  19. [Population and family planning].

    PubMed

    Romero, H

    1977-12-01

    This work consists of a speech read before the Adacemy of Medicine of the Institute of Chile and a brief debate by members of the audience. Misinformed opponents of birth control who argue among other things that family planning is a US plot ignore the fact that the desire to avoid pregnancy dates from the remote past, as attested by evidence from early Egyptian papyruses. Recent sharp declines in human mortality have led to unprecedented population growth. Around the beginning of the modern era the world contained about 250 million people, a population which did not double until the mid 1600s. Today world population doubles in 30 to 35 years, and by the end of the century it may reach 7 billion. The impact of such growth on the food supply, housing, the economy, education, and the environment have been the object of many studies, predominant among them those presented at the World Population Conferences in Rome, Belgrade, and Bucharest. The family planning program in Chile was initiated around 1962 although some activities had been carried out earlier. The Chilean Association for the Protection of the Family, a private organization, grew out of these early efforts and enjoyed considerable success from its earliest days. The natality rate declined from 38/1000 in 1962 to 23.5/1000 in 1977, and infant and maternal mortality also declined. The decline has been concentrated in births after age 30 and in high parity births. The young age structure means that the population will continue to increase for the foreseeable future.

  20. [The Marxist outlook on population].

    PubMed

    Qin, R

    1984-09-29

    Marxist population theory and world population are discussed. From his study of capitalist population theory Marx concluded, "In capitalist reproduction, poverty produces population," thus rejecting Malthusian population determinism theory and developing economic determinism. According to UN statistics, world population has stabilized since the middle of this century after having doubled every hundred years for the last 300; population in the developed countries showed a positive decrease and average net population growth of the developing countries also decreased. The premise of this paper is that population grows according to social economy development. During the last several hundred years, world wealth increased much faster than population; in the last 200 years alone, the population has increased fivefold, but wealth fortyfold. In addition, world population analysis reveals an inverse relationship between wealth and population in the developed and developing countries: the poorer the country, the greater the population. From this perspective, the study of population must begin with surplus labor. Accumulation of surplus production is the foundation of continuous social development and the basis for population growth. The major difference in methods between capitalist countries and China is that the capitalist-planned fertility affects the individual family while Chinese-planned fertility has the whole nation in mind. Human fertility is determined by the economic system. Private ownership determines the private nature of fertility and public ownership determines the public nature of fertility. Thus population development is determined by the accumulation of social wealth.