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Sample records for 8-year-old transgenic poplar

  1. Diversity of arthropod community in transgenic poplar-cotton ecosystems.

    PubMed

    Zhang, D J; Lu, Z Y; Liu, J X; Li, C L; Yang, M S

    2015-12-02

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of plain cotton fields in China. Here, we performed a systematic survey of the diversity and population of arthropod communities in four different combination of poplar-cotton eco-systems, including I) non-transgenic poplar and non-transgenic cotton fields; II) non-transgenic poplar and transgenic cotton fields [Bacillus thuringiensis (Bt) cotton]; III) Bt transgenic poplar (high insect resistant strain Pb29) and non-transgenic cotton; and IV) transgenic poplar and transgenic cotton fields, over a period of 3 years. Based on the statistical methods used to investigate community ecology, the effects of transgenic ecosystems on the whole structure of the arthropod community, on the structure of arthropods in the nutritive layer, and on the similarity of arthropod communities were evaluated. The main results were as follows: the transgenic poplar-cotton ecosystem has a stronger inhibitory effect on insect pests and has no impact on the structure of the arthropod community, and therefore, maintains the diversity of the arthropod community. The character index of the community indicated that the structure of the arthropod community of the transgenic poplar-cotton ecosystem was better than that of the poplar-cotton ecosystem, and that system IV had the best structure. As for the abundance of nutritional classes, the transgenic poplar-cotton ecosystem was also better than that of the non-transgenic poplar-cotton ecosystem. The cluster analysis and similarity of arthropod communities between the four different transgenic poplar-cotton ecosystems illustrated that the structure of the arthropod community excelled in the small sample of the transgenic poplar-cotton ecosystems.

  2. CPR - child 1 to 8 years old - slideshow

    MedlinePlus

    ... medlineplus.gov/ency/presentations/100215.htm CPR - child 1 to 8 years old - series—Check for responsiveness ... this page, please enable JavaScript. Go to slide 1 out of 3 Go to slide 2 out ...

  3. Conjunctival fibrous histiocytoma in an 8-year-old boy.

    PubMed

    Knapp, Austen N; Samara, Wasim A; Shields, Carol L; Shields, Jerry A; Eagle, Ralph C

    2016-08-01

    An 8-year-old healthy boy underwent surgery for excision of a painless, enlarging vascularized conjunctival tumor. Histopathology disclosed a mass comprised of interweaving spindle cells and scattered histiocytes in a fibrous matrix, consistent with benign fibrous histiocytoma. This rare tumor can resemble several conditions, including scleritis/episcleritis, inflamed pterygium, juvenile xanthogranuloma, foreign body granuloma, solitary fibrous tumor, amelanotic melanoma, and squamous cell carcinoma.

  4. Response of transgenic poplar overexpressing cytosolic glutamine synthetase to phosphinothricin.

    PubMed

    Pascual, María Belén; Jing, Zhong Ping; Kirby, Edward G; Cánovas, Francisco M; Gallardo, Fernando

    2008-01-01

    Glutamine synthetase (GS) is the main enzyme involved in ammonia assimilation in plants and is the target of phosphinothricin (PPT), an herbicide commonly used for weed control in agriculture. As a result of the inhibition of GS, PPT also blocks photorespiration, resulting in the depletion of leaf amino acid pools leading to the plant death. Hybrid transgenic poplar (Populus tremula x P. alba INRA clone 7171-B4) overexpressing cytosolic GS is characterized by enhanced vegetative growth [Gallardo, F., Fu, J., Cantón, F.R., García-Gutiérrez, A., Cánovas, F.M., Kirby, E.G., 1999. Expression of a conifer glutamine synthetase gene in transgenic poplar. Planta 210, 19-26; Fu, J., Sampalo, R., Gallardo, F., Cánovas, F.M., Kirby, E.G., 2003. Assembly of a cytosolic pine glutamine synthetase holoenzyme in leaves of transgenic poplar leads to enhanced vegetative growth in young plants. Plant Cell Environ. 26, 411-418; Jing, Z.P., Gallardo, F., Pascual, M.B., Sampalo, R., Romero, J., Torres de Navarra, A., Cánovas, F.M., 2004. Improved growth in a field trial of transgenic hybrid poplar overexpressing glutamine synthetase. New Phytol. 164, 137-145], increased photosynthetic and photorespiratory capacities [El-Khatib, R.T., Hamerlynck, E.P., Gallardo, F., Kirby, E.G., 2004. Transgenic poplar characterized by ectopic expression of a pine cytosolic glutamine synthetase gene exhibits enhanced tolerance to water stress. Tree Physiol. 24, 729-736], enhanced tolerance to water stress (El-Khatib et al., 2004), and enhanced nitrogen use efficiency [Man, H.-M., Boriel, R., El-Khatib, R.T., Kirby, E.G., 2005. Characterization of transgenic poplar with ectopic expression of pine cytosolic glutamine synthetase under conditions of varying nitrogen availability. New Phytol. 167, 31-39]. In vitro plantlets of GS transgenic poplar exhibited enhanced resistance to PPT when compared with non-transgenic controls. After 30 days exposure to PPT at an equivalent dose of 275 g ha(-1), growth

  5. Balancing on a Slackline: 8-Year-Olds vs. Adults

    PubMed Central

    Schärli, Andrea Melanie; Keller, Melanie; Lorenzetti, Silvio; Murer, Kurt; van de Langenberg, Rolf

    2013-01-01

    Children are less stable than adults during static upright stance. We investigated whether the same holds true for a task that was novel for both children and adults and highly dynamic: single-legged stance on a slackline. We compared 8-year-olds with young adults and assessed the following outcome measures: time on the slackline, stability on the slackline (calculated from slackline reaction force), gaze movement, head-in-space rotation and translation, trunk-in-space rotation, and head-on-trunk rotation. Eight-year-olds fell off the slackline quicker and were generally less stable on the slackline than adults. Eight-year-olds also showed more head-in-space rotation and translation, and more gaze variability around a visual anchor point they were instructed to fixate. Trunk-in-space and head-on-trunk rotations did not differ between groups. The results imply that the lower postural stability of 8-year-olds compared to adults – as found in simple upright stance – holds true for dynamic, novel tasks in which adults lack the advantage of more practice. They also suggest that the lack of head and gaze stability constitutes an important limiting factor in children’s ability to master such tasks. PMID:23626583

  6. Chloroplast parameters differ in wild type and transgenic poplars overexpressing gsh1 in the cytosol.

    PubMed

    Ivanova, L A; Ronzhina, D A; Ivanov, L A; Stroukova, L V; Peuke, A D; Rennenberg, H

    2009-07-01

    Poplar mutants overexpressing the bacterial genes gsh1 or gsh2 encoding the enzymes of glutathione biosynthesis are among the best-characterised transgenic plants. However, this characterisation originates exclusively from laboratory studies, and the performance of these mutants under field conditions is largely unknown. Here, we report a field experiment in which the wild-type poplar hybrid Populus tremula x P. alba and a transgenic line overexpressing the bacterial gene gsh1 encoding gamma-glutamylcysteine synthetase in the cytosol were grown for 3 years at a relatively clean (control) field site and a field site contaminated with heavy metals. Aboveground biomass accumulation was slightly smaller in transgenic compared to wild-type plants; soil contamination significantly decreased biomass accumulation in both wild-type and transgenic plants by more than 40%. Chloroplasts parameters, i.e., maximal diameter, projection area and perimeter, surface area and volume, surface/volume ratio and a two-dimensional form coefficient, were found to depend on plant type, leaf tissue and soil contamination. The greatest differences between wild and transgenic poplars were observed at the control site. Under these conditions, chloroplast sizes in palisade tissue of transgenic poplar significantly exceeded those of the wild type. In contrast to the wild type, palisade chloroplast volume exceeded that of spongy chloroplasts in transgenic poplars at both field sites. Chlorophyll content per chloroplast was the same in wild and transgenic poplars. Apparently, the increase in chloroplast volume was not connected to changes in the photosynthetic centres. Chloroplasts of transgenic poplar at the control site were more elongated in palisade cells and close to spherical in spongy mesophyll chloroplasts. At the contaminated site, palisade and spongy cell chloroplasts of leaves from transgenic trees and the wild type were the same shape. Transgenic poplars also had a smaller chloroplast

  7. Impacts of transgenic poplar-cotton agro-ecosystems upon target pests and non-target insects under field conditions.

    PubMed

    Zhang, D J; Liu, J X; Lu, Z Y; Li, C L; Comada, E; Yang, M S

    2015-01-01

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of cotton fields in China. With increasing acres devoted to transgenic insect-resistant poplar and transgenic insect-resistant cotton, studies examining the effects of transgenic plants on target and non-target insects become increasingly important. We systematically surveyed populations of both target pests and non-target insects for 4 different combinations of poplar-cotton eco-systems over 3 years. Transgenic Bt cotton strongly resisted the target insects Fall webworm moth [Hyphantria cunea (Drury)], Sylepta derogata Fabrieius, and American bollworm (Heliothis armigera), but no clear impact on non-target insect cotton aphids (Aphis gossypii). Importantly, intercrops containing transgenic Pb29 poplar significantly increased the inhibitory effects of Bt cotton on Fall webworm moth in ecosystem IV. Highly resistant Pb29 poplar reduced populations of the target pests Grnsonoma minutara Hubner and non-target insect poplar leaf aphid (Chaitophorus po-pulialbae), while Fall webworm moth populations were unaffected. We determined the effects of Bt toxin from transgenic poplar and cotton on target and non-target pests in different ecosystems of cotton-poplar intercrops and identified the synergistic effects of such combinations toward both target and non-target insects. PMID:26345739

  8. Impacts of transgenic poplar-cotton agro-ecosystems upon target pests and non-target insects under field conditions.

    PubMed

    Zhang, D J; Liu, J X; Lu, Z Y; Li, C L; Comada, E; Yang, M S

    2015-07-27

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of cotton fields in China. With increasing acres devoted to transgenic insect-resistant poplar and transgenic insect-resistant cotton, studies examining the effects of transgenic plants on target and non-target insects become increasingly important. We systematically surveyed populations of both target pests and non-target insects for 4 different combinations of poplar-cotton eco-systems over 3 years. Transgenic Bt cotton strongly resisted the target insects Fall webworm moth [Hyphantria cunea (Drury)], Sylepta derogata Fabrieius, and American bollworm (Heliothis armigera), but no clear impact on non-target insect cotton aphids (Aphis gossypii). Importantly, intercrops containing transgenic Pb29 poplar significantly increased the inhibitory effects of Bt cotton on Fall webworm moth in ecosystem IV. Highly resistant Pb29 poplar reduced populations of the target pests Grnsonoma minutara Hubner and non-target insect poplar leaf aphid (Chaitophorus po-pulialbae), while Fall webworm moth populations were unaffected. We determined the effects of Bt toxin from transgenic poplar and cotton on target and non-target pests in different ecosystems of cotton-poplar intercrops and identified the synergistic effects of such combinations toward both target and non-target insects.

  9. Analyzing the Responses of 7-8 Year Olds When Solving Partitioning Problems

    ERIC Educational Resources Information Center

    Badillo, Edelmira; Font, Vicenç; Edo, Mequè

    2015-01-01

    We analyze the mathematical solutions of 7- to 8-year-old pupils while individually solving an arithmetic problem. The analysis was based on the "configuration of objects," an instrument derived from the onto-semiotic approach to mathematical knowledge. Results are illustrated through a number of cases. From the analysis of mathematical…

  10. Radiator-induced erythema ab igne in 8-year-old girl.

    PubMed

    Brzezinski, Piotr; Ismail, Samir; Chiriac, Anca

    2014-04-01

    The cutaneous lesion of erythema ab Igne are characterized by a reticulate erythema, hyperpigmentation, fine scaling, epidermal atrophy and telangiectasias, and reticulated erythema. We report a case of erythema ab igne on the hands of a 8-year-old girl, induced by classic homemade radiator.

  11. Five- to 8-Year-Old Emirati Children's and Their Teachers' Perceptions of War

    ERIC Educational Resources Information Center

    Buldu, Mehmet

    2009-01-01

    This study examined 5- to 8-year-old Emirati children's and their teachers' perceptions of war. Data for this study were collected through drawings and semi-structured interviews. A phenomenological procedure was used to analyze the data. Younger children could not articulate the details of the specific nature of war. Many children defined war as…

  12. Transgenic poplar expressing the pine GS1a show alterations in nitrogen homeostasis during drought.

    PubMed

    Molina-Rueda, Juan Jesús; Kirby, Edward G

    2015-09-01

    Transgenic hybrid poplars engineered to express ectopically the heterologous pine cytosolic GS1a display a number of significant pleiotropic phenotypes including enhanced growth, enhanced nitrogen use efficiency, and resistance to drought stress. The present study was undertaken in order to assess mechanisms whereby ectopic expression of pine GS1a in transgenic poplars results in enhanced agronomic phenotypes. Microarray analysis using the Agilent Populus whole genome array has allowed identification of genes differentially expressed between wild type (WT) and GS transgenics in four tissues (sink leaves, source leaves, stems, and roots) under three growth conditions (well-watered, drought, and recovery). Analysis revealed that differentially expressed genes in functional categories related to nitrogen metabolism show a trend of significant down-regulation in GS poplars compared to the WT, including genes encoding nitrate and nitrite reductases. The down-regulation of these genes was verified using qPCR, and downstream effects were further tested using NR activity assays. Results suggest that higher glutamine levels in GS transgenics regulate nitrate uptake and reduction. Transcript levels of nitrogen-related genes in leaves, including GS/GOGAT cycle enzymes, aspartate aminotransferase, GABA shunt enzymes, photorespiration enzymes, asparagine synthetase, phenylalanine ammonia lyase, isocitrate dehydrogenase, and PII, were also assessed using qPCR revealing significant differences between GS poplars and the WT. Moreover, metabolites related to these differentially expressed genes showed alterations in levels, including higher levels of GABA, hydroxyproline, and putrescine in the GS transgenic. These alterations in nitrogen homeostasis offer insights into mechanisms accounting for drought tolerance observed in GS poplars. PMID:26113157

  13. Transgenic poplar expressing the pine GS1a show alterations in nitrogen homeostasis during drought.

    PubMed

    Molina-Rueda, Juan Jesús; Kirby, Edward G

    2015-09-01

    Transgenic hybrid poplars engineered to express ectopically the heterologous pine cytosolic GS1a display a number of significant pleiotropic phenotypes including enhanced growth, enhanced nitrogen use efficiency, and resistance to drought stress. The present study was undertaken in order to assess mechanisms whereby ectopic expression of pine GS1a in transgenic poplars results in enhanced agronomic phenotypes. Microarray analysis using the Agilent Populus whole genome array has allowed identification of genes differentially expressed between wild type (WT) and GS transgenics in four tissues (sink leaves, source leaves, stems, and roots) under three growth conditions (well-watered, drought, and recovery). Analysis revealed that differentially expressed genes in functional categories related to nitrogen metabolism show a trend of significant down-regulation in GS poplars compared to the WT, including genes encoding nitrate and nitrite reductases. The down-regulation of these genes was verified using qPCR, and downstream effects were further tested using NR activity assays. Results suggest that higher glutamine levels in GS transgenics regulate nitrate uptake and reduction. Transcript levels of nitrogen-related genes in leaves, including GS/GOGAT cycle enzymes, aspartate aminotransferase, GABA shunt enzymes, photorespiration enzymes, asparagine synthetase, phenylalanine ammonia lyase, isocitrate dehydrogenase, and PII, were also assessed using qPCR revealing significant differences between GS poplars and the WT. Moreover, metabolites related to these differentially expressed genes showed alterations in levels, including higher levels of GABA, hydroxyproline, and putrescine in the GS transgenic. These alterations in nitrogen homeostasis offer insights into mechanisms accounting for drought tolerance observed in GS poplars.

  14. Transgenic Hybrid Poplar for Sustainable and Scalable Production of the Commodity/Specialty Chemical, 2-Phenylethanol

    PubMed Central

    Costa, Michael A.; Marques, Joaquim V.; Dalisay, Doralyn S.; Herman, Barrington; Bedgar, Diana L.; Davin, Laurence B.; Lewis, Norman G.

    2013-01-01

    Fast growing hybrid poplar offers the means for sustainable production of specialty and commodity chemicals, in addition to rapid biomass production for lignocellulosic deconstruction. Herein we describe transformation of fast-growing transgenic hybrid poplar lines to produce 2-phenylethanol, this being an important fragrance, flavor, aroma, and commodity chemical. It is also readily converted into styrene or ethyl benzene, the latter being an important commodity aviation fuel component. Introducing this biochemical pathway into hybrid poplars marks the beginnings of developing a platform for a sustainable chemical delivery system to afford this and other valuable specialty/commodity chemicals at the scale and cost needed. These modified plant lines mainly sequester 2-phenylethanol via carbohydrate and other covalently linked derivatives, thereby providing an additional advantage of effective storage until needed. The future potential of this technology is discussed. MALDI metabolite tissue imaging also established localization of these metabolites in the leaf vasculature. PMID:24386157

  15. Transgenic hybrid poplar for sustainable and scalable production of the commodity/specialty chemical, 2-phenylethanol.

    PubMed

    Costa, Michael A; Marques, Joaquim V; Dalisay, Doralyn S; Herman, Barrington; Bedgar, Diana L; Davin, Laurence B; Lewis, Norman G

    2013-01-01

    Fast growing hybrid poplar offers the means for sustainable production of specialty and commodity chemicals, in addition to rapid biomass production for lignocellulosic deconstruction. Herein we describe transformation of fast-growing transgenic hybrid poplar lines to produce 2-phenylethanol, this being an important fragrance, flavor, aroma, and commodity chemical. It is also readily converted into styrene or ethyl benzene, the latter being an important commodity aviation fuel component. Introducing this biochemical pathway into hybrid poplars marks the beginnings of developing a platform for a sustainable chemical delivery system to afford this and other valuable specialty/commodity chemicals at the scale and cost needed. These modified plant lines mainly sequester 2-phenylethanol via carbohydrate and other covalently linked derivatives, thereby providing an additional advantage of effective storage until needed. The future potential of this technology is discussed. MALDI metabolite tissue imaging also established localization of these metabolites in the leaf vasculature. PMID:24386157

  16. Poststroke psychosis in an 8-year-old child with moyamoya disease.

    PubMed

    Gnanavel, Sundar

    2013-01-01

    Psychiatric illnesses following cerebrovascular accidents has been a popular area of research in recent times. Though poststroke anxiety and mood disorders including depression have been reported often, reports of poststroke psychosis have been considerably rarer. This case report documents an even rarer occurrence of a psychotic disorder in an 8-year-old child with moyamoya disease following a cerebrovascular accident. The child was managed with low-dose atypical antipsychotic, risperidone and the psychotic symptoms eventually were under control around 3 weeks following the initiation of psychotropic medication.

  17. Isolated Splenic Vein Thrombosis: 8-Year-Old Boy with Massive Upper Gastrointestinal Bleeding and Hypersplenism.

    PubMed

    Kiani, Mohammad Ali; Forouzan, Arash; Masoumi, Kambiz; Mazdaee, Behnaz; Bahadoram, Mohammad; Kianifar, Hamid Reza; Ravari, Hassan

    2015-01-01

    We present an 8-year-old boy who was referred to our center with the complaint of upper gastrointestinal bleeding and was diagnosed with hypersplenism and progressive esophageal varices. Performing a computerized tomography (CT) scan, we discovered a suspicious finding in the venography phase in favor of thrombosis in the splenic vein. Once complementary examinations were done and due to recurrent bleeding and band ligation failure, the patient underwent splenectomy. And during the one-year follow-up obvious improvement of the esophageal varices was observed in endoscopy.

  18. Neuroleptic withdrawal versus serotonergic syndrome in an 8-year-old child.

    PubMed

    Godinho, Elsa M M; Thompson, Anne E; Bramble, David J

    2002-01-01

    There appears to be considerable symptomatic overlap between neuroleptic withdrawal reactions and the serotonin syndrome. This case report is of an 8-year-old boy who developed symptoms compatible with both conditions while discontinuing pimozide and starting fluoxetine. It illustrates how the use of neuroleptic medication in young children is not without the risk of serious adverse drug events and can complicate diagnostic issues. This case report supports the suggestion that adverse drug reactions related to neuroleptics and serotonergic agents could be part of the same clinical and neurophysiological spectrum.

  19. Neuroleptic withdrawal versus serotonergic syndrome in an 8-year-old child.

    PubMed

    Godinho, Elsa M M; Thompson, Anne E; Bramble, David J

    2002-01-01

    There appears to be considerable symptomatic overlap between neuroleptic withdrawal reactions and the serotonin syndrome. This case report is of an 8-year-old boy who developed symptoms compatible with both conditions while discontinuing pimozide and starting fluoxetine. It illustrates how the use of neuroleptic medication in young children is not without the risk of serious adverse drug events and can complicate diagnostic issues. This case report supports the suggestion that adverse drug reactions related to neuroleptics and serotonergic agents could be part of the same clinical and neurophysiological spectrum. PMID:12427301

  20. Age and gender dependent development of Theory of Mind in 6- to 8-years old children.

    PubMed

    Calero, Cecilia I; Salles, Alejo; Semelman, Mariano; Sigman, Mariano

    2013-01-01

    The ability to attribute different mental states to distinct individuals, or Theory of Mind (ToM), is widely believed to be developed mostly during preschool years. How different factors such as gender, number of siblings, or coarse personality traits affect this development is not entirely agreed upon. Here, we introduce a computerized version of the scaled ToM suite of tasks introduced by Wellman and Liu (2004), which allows us to meaningfully test ToM development on children 6 to 8-years old. We find that kids this age are still not entirely proficient in all ToM tasks, and continue to show a progression of performance with age. By testing this new age range, too, we are able to observe a significant advantage of girls over boys in ToM performance. Other factors such as number of siblings, birth order, and coarse personality traits show no significant relation with the ToM task results. Finally, we introduce a novel way to quantify the scaling property of the suite involving a sequence of set inclusions on one hand and a comparison between specially tailored sets of logistic models on the other. These measures confirm the validity of the scale in the 6- to 8-years old range.

  1. POLYGON - A New Fundamental Movement Skills Test for 8 Year Old Children: Construction and Validation

    PubMed Central

    Zuvela, Frane; Bozanic, Ana; Miletic, Durdica

    2011-01-01

    Inadequately adopted fundamental movement skills (FMS) in early childhood may have a negative impact on the motor performance in later life (Gallahue and Ozmun, 2005). The need for an efficient FMS testing in Physical Education was recognized. The aim of this paper was to construct and validate a new FMS test for 8 year old children. Ninety-five 8 year old children were used for the testing. A total of 24 new FMS tasks were constructed and only the best representatives of movement areas entered into the final test product - FMS-POLYGON. The ICC showed high values for all 24 tasks (0.83-0.97) and the factorial analysis revealed the best representatives of each movement area that entered the FMS-POLYGON: tossing and catching the volleyball against a wall, running across obstacles, carrying the medicine balls, and straight running. The ICC for the FMS-POLYGON showed a very high result (0.98) and, therefore, confirmed the test’s intra-rater reliability. Concurrent validity was tested with the use of the “Test of Gross Motor Development” (TGMD-2). Correlation analysis between the newly constructed FMS-POLYGON and the TGMD-2 revealed the coefficient of -0.82 which indicates a high correlation. In conclusion, the new test for FMS assessment proved to be a reliable and valid instrument for 8 year old children. Application of this test in schools is justified and could play an important factor in physical education and sport practice. Key points All 21 newly constructed tasks demonstrated high intra-rater reliability (0.83-0.97) in FMS assessment. High reliability was also noted in the FMS-POLYGON test (0.98). A high correlation was found between the FMS-POLYGON and TGMD-2 which is a confirmation of the new test’s concurrent validity. The research resolved the problem of long and detailed FMS assessment by adding a new dimension using quick and effective norm-referenced approach but also covering all the most important movement areas. New and validated test can be

  2. POLYGON - A New Fundamental Movement Skills Test for 8 Year Old Children: Construction and Validation.

    PubMed

    Zuvela, Frane; Bozanic, Ana; Miletic, Durdica

    2011-01-01

    Inadequately adopted fundamental movement skills (FMS) in early childhood may have a negative impact on the motor performance in later life (Gallahue and Ozmun, 2005). The need for an efficient FMS testing in Physical Education was recognized. The aim of this paper was to construct and validate a new FMS test for 8 year old children. Ninety-five 8 year old children were used for the testing. A total of 24 new FMS tasks were constructed and only the best representatives of movement areas entered into the final test product - FMS-POLYGON. The ICC showed high values for all 24 tasks (0.83-0.97) and the factorial analysis revealed the best representatives of each movement area that entered the FMS-POLYGON: tossing and catching the volleyball against a wall, running across obstacles, carrying the medicine balls, and straight running. The ICC for the FMS-POLYGON showed a very high result (0.98) and, therefore, confirmed the test's intra-rater reliability. Concurrent validity was tested with the use of the "Test of Gross Motor Development" (TGMD-2). Correlation analysis between the newly constructed FMS-POLYGON and the TGMD-2 revealed the coefficient of -0.82 which indicates a high correlation. In conclusion, the new test for FMS assessment proved to be a reliable and valid instrument for 8 year old children. Application of this test in schools is justified and could play an important factor in physical education and sport practice. Key pointsAll 21 newly constructed tasks demonstrated high intra-rater reliability (0.83-0.97) in FMS assessment. High reliability was also noted in the FMS-POLYGON test (0.98).A high correlation was found between the FMS-POLYGON and TGMD-2 which is a confirmation of the new test's concurrent validity.The research resolved the problem of long and detailed FMS assessment by adding a new dimension using quick and effective norm-referenced approach but also covering all the most important movement areas.New and validated test can be of great use

  3. Rapunzel Syndrome Causing Appendicitis in an 8-year-old Girl

    PubMed Central

    Dogra, Shruti; Yadav, Yogesh Kumar; Sharma, Uma; Gupta, Kusum

    2012-01-01

    Rapunzel syndrome is a rare type of presentation of trichobezoar, an extension of hair fibers into the small bowel and rarely beyond the ileocecal valve. Its clinical presentation is deceptive ranging from abdominal mass to symptoms of obstruction. We report a 8-year-old girl admitted with a history of abdominal pain and vomiting off and on for a period of 1 year. Ultrasound findings were suggestive of subacute intestinal obstruction. On laparotomy, trichobezoar was found in the stomach extending into small bowel and was removed. Appendix was inflammed hence it was also resected. Microscopic evidence of a hair shaft was seen in the appendix indicating appendicitis was due to luminal obstruction by hair concretions. PMID:23766615

  4. Developing formal mathematical assessment for 4- to 8-year-olds

    NASA Astrophysics Data System (ADS)

    Doig, Brian

    2005-10-01

    The assessment of children in their years before school and their first years of school has been, traditionally, informal. Further, assessment of children's mathematical skills at this level has been infrequent compared to social, emotional and physical assessments. However, there are contexts where reliable, valid, standardised data from assessment in mathematics are required. This paper outlines the development of two assessment tools for mathematics that were originally developed for such contexts. Item Response Theory (IRT) analyses enabled the construction of assessment forms that address the range of abilities of 4- to 8-year-old children, and provided the scales used for constructing formative and summative reports of achievement. A description of the development of the assessment tools and the IRT analysis that provides the reporting formats are presented together with some research uses of the tools.

  5. Racial Differences in Reported Napping and Nocturnal Sleep in 2- to 8-Year-Old Children

    PubMed Central

    Crosby, Brian; LeBourgeois, Monique K.; Harsh, John

    2010-01-01

    Objectives The objectives of this study were to examine racial differences in reported napping and nighttime sleep of 2- to 8-year-old children, to identify factors accounting for these differences, and to determine if variability in napping was related to psychosocial functioning. Methods Caretakers of 1043 children (73.5% non-Hispanic white; 50.4% male) 2 to 8 years old from a community sample reported on their children’s napping behavior and nighttime sleep. Caretakers of 255 preschool children (3–5 years old) also completed the Behavior Assessment System for Children. Results A more gradual age-related decline in napping was found for black children. At age 8, 39.1% of black children were reported to nap, compared with only 4.9% of white children. Black children also napped significantly more days per week, had shorter average nocturnal sleep durations, and slept significantly less on weekdays than on weekend nights. Despite differences in sleep distribution, total weekly sleep duration (diurnal and nocturnal) was nearly identical for the 2 racial groups at each year of age. Logistic regression analysis revealed that demographic variables were related to but did not fully explain napping differences. Napping in a subset of preschoolers was not significantly related to psychosocial functioning. Conclusions There are remarkable racial differences in reported napping and nighttime sleep patterns beginning as early as age 3 and extending to at least 8 years of age. These differences are independent of commonly investigated demographic factors. Differences in napping behavior do not seem to have psychosocial significance in a sample of preschool children. PMID:15866856

  6. Over-expression of poplar transcription factor ERF76 gene confers salt tolerance in transgenic tobacco.

    PubMed

    Yao, Wenjing; Wang, Lei; Zhou, Boru; Wang, Shengji; Li, Renhua; Jiang, Tingbo

    2016-07-01

    Ethylene response factors (ERFs) belong to a large plant-specific transcription factor family, which play a significant role in plant development and stress responses. Poplar ERF76 gene, a member of ERF TF family, can be up-regulated in response to salt stress, osmotic stress, and ABA treatment. The ERF76 protein was confirmed to be targeted preferentially in the nucleus of onion cell by particle bombardment. In order to understand the functions of ERF76 gene in salt stress response, we conducted temporal and spatial expression analysis of ERF76 gene in poplar. Then the ERF76 cDNA fragment containing an ORF was cloned from di-haploid Populus simonii×P. nigra and transferred into tobacco (Nicotiana tobacum) genome by Agrobacterium-mediated leaf disc method. Under salt stress, transgenic tobacco over-expressing ERF76 gene showed a significant increase in seed germination rate, plant height, root length, and fresh weight, as well as in relative water content (RWC), superoxide dismutase (SOD) activity, peroxidase (POD) activity, and proline content, compared to control tobacco lines. In contrast, transgenic tobacco lines displayed a decrease in malondialdehyde (MDA) accumulation, relative electrical conductivity (REC) and reactive oxygen species (ROS) accumulation in response to salt stress, compared to control tobacco lines. Over all, the results indicated that ERF76 gene plays a critical role in salt tolerance in transgenic tobacco. PMID:27123829

  7. Transgenic Manipulation of the Metabolism of Polyamines in Poplar Cells1

    PubMed Central

    Bhatnagar, Pratiksha; Glasheen, Bernadette M.; Bains, Suneet K.; Long, Stephanie L.; Minocha, Rakesh; Walter, Christian; Minocha, Subhash C.

    2001-01-01

    The metabolism of polyamines (putrescine, spermidine, and spermine) has become the target of genetic manipulation because of their significance in plant development and possibly stress tolerance. We studied the polyamine metabolism in non-transgenic (NT) and transgenic cells of poplar (Populus nigra × maximowiczii) expressing a mouse Orn decarboxylase (odc) cDNA. The transgenic cells showed elevated levels of mouse ODC enzyme activity, severalfold higher amounts of putrescine, a small increase in spermidine, and a small reduction in spermine as compared with NT cells. The conversion of labeled ornithine (Orn) into putrescine was significantly higher in the transgenic than the NT cells. Whereas exogenously supplied Orn caused an increase in cellular putrescine in both cell lines, arginine at high concentrations was inhibitory to putrescine accumulation. The addition of urea and glutamine had no effect on polyamines in either of the cell lines. Inhibition of glutamine synthetase by methionine sulfoximine led to a substantial reduction in putrescine and spermidine in both cell lines. The results show that: (a) Transgenic expression of a heterologous odc gene can be used to modulate putrescine metabolism in plant cells, (b) accumulation of putrescine in high amounts does not affect the native arginine decarboxylase activity, (c) Orn biosynthesis occurs primarily from glutamine/glutamate and not from catabolic breakdown of arginine, (d) Orn biosynthesis may become a limiting factor for putrescine production in the odc transgenic cells, and (e) assimilation of nitrogen into glutamine keeps pace with an increased demand for its use for putrescine production. PMID:11299393

  8. Efficient and stable transgene suppression via RNAi in field-grown poplars.

    PubMed

    Li, Jingyi; Brunner, Amy M; Shevchenko, Olga; Meilan, Richard; Ma, Cathleen; Skinner, Jeffrey S; Strauss, Steven H

    2008-08-01

    The efficiency and stability of RNA interference (RNAi) in perennial species, particularly in natural environments, is poorly understood. We studied 56 independent poplar RNAi transgenic events in the field over 2 years. A resident BAR transgene was targeted with two different types of RNAi constructs: a 475-bp IR of the promoter sequence and a 275-bp IR of the coding sequence, each with and without the presence of flanking matrix attachment regions (MARs). RNAi directed at the coding sequence was a strong inducer of gene silencing; 80% of the transgenic events showed more than 90% suppression. In contrast, RNAi targeting the promoter resulted in only 6% of transgenic events showing more than 90% suppression. The degree of suppression varied widely but was highly stable in each event over 2 years in the field, and had no association with insert copy number or the presence of MARs. RNAi remained stable during a winter to summer seasonal cycle, a time when expression of the targeted transgene driven by an rbcS promoter varied widely. When strong gene suppression was induced by an IR directed at the promoter sequence, it was accompanied by methylation of the homologous promoter region. DNA methylation was also observed in the coding region of highly suppressed events containing an IR directed at the coding sequence; however, the methylation degree and pattern varied widely among those suppressed events. Our results suggest that RNAi can be highly effective for functional genomics and biotechnology of perennial plants. PMID:17929189

  9. Stabbing headache in an 8-year-old girl: primary or drug induced headache?

    PubMed

    Biedroł, Agnieszka; Kaciłski, Marek; Skowronek-Bała, Barbara

    2014-04-01

    The occurrence of stabbing headaches in children requires a thorough diagnostic approach that excludes secondary headaches. The organic background should be taken into consideration when alarming symptoms occur, such as a purely 1-sided location, a change in the character of the headache, or possibly a link to physical activity. The current study describes the case of an 8-year-old girl who suffered short-lasting stabbing headache attacks. The headaches with increasing intensity and frequency started 1 month before her hospitalization and were usually preceded by physical activity (dancing, running). The pain, which was located in the right supraorbital region, lasted 1 second and occurred several times during the day. No associated symptoms were observed. In addition, the girl suffered from allergic rhinitis and was on antiallergic treatment (levocetirizine, fluticasone nasal spray). On admission she was in good general condition, and a pediatric and neurologic examination revealed no abnormalities. Her brain MRI was normal. The initial diagnosis was that the patient was suffering from primary stabbing headaches. However, during a follow-up visit 4 months later, a relationship was observed between the cessation of the headache attacks and the discontinuation of an antihistaminic drug. Six months later, the girl remained headache free. In cases involving differential diagnoses of stabbing headaches, it is important to consider the adverse reactions of the drugs used.

  10. Perivascular epithelioid cell tumour of the vagina in an 8 year old girl.

    PubMed

    Ong, Lin Yin; Hwang, Wei Sek; Wong, Adelina; Chan, Mei Yoke; Chui, Chan Hon

    2007-03-01

    Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor with an unpredictable natural history. We present the first reported case of PEComa of the vagina diagnosed in an 8-year-old girl. This was initially diagnosed on biopsy as an embryonal rhabdomyosarcoma, and the patient underwent 3 cycles of chemotherapy according to the Mesenchymal Malignant Tumour 1989 protocol. A repeat scan, however, revealed an increase in tumor size. Total resection was achieved via a transvaginal (vertical sleeve) partial vaginectomy. The resected tumor had the typical appearance of a PEComa. Immunostains showed positive staining of tumor cells for HMB45, neuron-specific enolase, and calponin but were negative for S100 protein, melaninA, chromogranin, smooth muscle actin, desmin, caldesmon, epithelial membrane antigen, AE1/3, and synaptophysin. Six months after surgery, she remains free of tumor and is on follow-up with regular local examinations under anesthesia and computed tomography scans. Our case highlights the importance of an accurate initial diagnosis, and we stress the importance of regular surveillance over a significant period. PMID:17336201

  11. Cycling peak power in obese and lean 6- to 8-year-old girls and boys.

    PubMed

    Aucouturier, Julien; Lazaar, Nordine; Doré, Eric; Meyer, Martine; Ratel, Sebastien; Duché, Pascale

    2007-06-01

    The purpose of this study was to investigate the possible effect of the difference in percentage body fat (%BF) and fat-free mass (FFM) on cycling peak power (CPP) in 6- to 8-year-old obese and lean untrained girls and boys. Obese (35 girls, 35 boys) and lean (35 girls, 35 boys) children were measured for obesity, %BF, calculated from skinfold measurements. FFM was calculated as body mass (BM) minus body fat. A force-velocity test on a cycle ergometer was used to measure CPP. CPP was related to anthropometric variables using standard and allometric models. CPP in absolute terms was higher in obese children than in lean children irrespective of gender. BM-related CPP was significantly lower in obese children than in lean ones, whereas no effect of obesity appeared on FFM-related CPP. Velocity at CPP (Vopt) was significantly lower and force at CPP (Fopt) was significantly higher in girls than in boys. Muscle power production was unaffected by obesity in children. Low BM-related CPP could explain the difficulty of taking up physical activities that are body-mass related in obese children. Gender difference for Vopt and Fopt shows that girls and boys may have different maturation patterns affecting CPP. PMID:17510670

  12. Complicated Varicella Infection at 8-year-old Boy with Pulmonary Agenesis

    PubMed Central

    Hadzovic–Cengic, Meliha; Baljic, Rusmir; Hadzic, Amir; Lukovac, Enra; Mehanic, Snjezana; Ahmetspahic-Begic, Aida

    2012-01-01

    SUMMARY CONFLICT OF INTEREST: none declared. Introduction Varicella or chickenpox is highly contagious, childhood infectious disease caused by primary infection with varicella – zoster virus from the herpes family of viruses. Usually it has a mild clinical course, rarely with described complication, mostly affecting respiratory tract and rarely the central nervous system. Case report The case present 8 year old boy hospitalized eighth day of disease with clinical pictures of varicella complication. Upon receipt tachydyspnea, high fever, tachycardia, hypotensive with positive findings on lung auscultation in the sense of pneumonia. Extremely high values of non-specific inflammatory parameters are implied on bacterial infection which is treated using triple antimicrobial therapy and antiviral. A detailed clinical, laboratory and radiological evaluation is determined of clinical disease complication under a picture of MODS that required prolonged multidisciplinary treatment in ICU. Conclusion The disease had a favorable clinical outcome in terms of training completely without consequences but, with the detected congenital absence lower lobe of right lung and transposition of the brachiocephalic trunk. PMID:24493991

  13. Stabbing headache in an 8-year-old girl: primary or drug induced headache?

    PubMed

    Biedroł, Agnieszka; Kaciłski, Marek; Skowronek-Bała, Barbara

    2014-04-01

    The occurrence of stabbing headaches in children requires a thorough diagnostic approach that excludes secondary headaches. The organic background should be taken into consideration when alarming symptoms occur, such as a purely 1-sided location, a change in the character of the headache, or possibly a link to physical activity. The current study describes the case of an 8-year-old girl who suffered short-lasting stabbing headache attacks. The headaches with increasing intensity and frequency started 1 month before her hospitalization and were usually preceded by physical activity (dancing, running). The pain, which was located in the right supraorbital region, lasted 1 second and occurred several times during the day. No associated symptoms were observed. In addition, the girl suffered from allergic rhinitis and was on antiallergic treatment (levocetirizine, fluticasone nasal spray). On admission she was in good general condition, and a pediatric and neurologic examination revealed no abnormalities. Her brain MRI was normal. The initial diagnosis was that the patient was suffering from primary stabbing headaches. However, during a follow-up visit 4 months later, a relationship was observed between the cessation of the headache attacks and the discontinuation of an antihistaminic drug. Six months later, the girl remained headache free. In cases involving differential diagnoses of stabbing headaches, it is important to consider the adverse reactions of the drugs used. PMID:24664098

  14. Infratentorial meningioma in an 8-year-old child as first sign of neurofibromatosis type 2.

    PubMed

    Stettner, G M; Rostasy, K M; Ludwig, H C; Merkler, D; Fahsold, R; Gärtner, J

    2007-02-01

    Meningiomas are rare intracranial tumors in pediatric patients. In contrast to meningiomas in adults, childhood ones have a poorer prognosis because of their high growth potential and tendency to recur. Meningiomas are often associated with neurofibromatosis type 2 (NF2) which is an autosomal-dominant disorder. In contrast to adults who primarily present with symptoms due to vestibular tumors, the initial symptoms in children with NF2 are subtle skin tumors, posterior capsular cataracts, or neurological signs secondary to cranial nerve(s) schwannoma excluding vestibular nerve, and/or brainstem or spinal cord compression. Here we report on the clinical, radiological, and histological findings in an 8-year-old boy who was diagnosed with an isolated infratentorial meningioma and a novel splice site mutation in the NF2 gene. The same mutation was detected in the boy's mother who suffered from hearing loss and tinnitus due to a bilateral vestibular schwannoma. Our patient demonstrates the need for molecular testing for NF2 gene mutations even in isolated childhood meningiomas although they do not fulfill the clinical criteria of NF2.

  15. Tryptamine-induced resistance in tryptophan decarboxylase transgenic poplar and tobacco plants against their specific herbivores.

    PubMed

    Gill, Rishi I S; Ellis, Brian E; Isman, Murray B

    2003-04-01

    The presence of amines and their derivatives in plant tissues is known to influence insect feeding and reproduction. The enzyme tryptophan decarboxylase (TDC) catalyzes the decarboxylation of tryptophan to tryptamine, which is both a bioactive amine and a precursor of other indole derivatives. Transgenic poplar and tobacco plants ectopically expressing TDC1 accumulated elevated levels of tryptamine without affecting plant growth and development. This accumulation was consistently associated with adverse effects on feeding behavior and physiology of Malacosoma disstria Hub. (forest tent caterpillar, FTC) and Manduca sexta L. (tobacco hornworm, THW). Behavior studies with FTC and THW larvae showed that acceptability of the leaf tissue to larvae was inversely related to foliar tryptamine levels. Physiological studies with FTC and THW larvae showed that consumption of leaf tissue from the transgenic lines is deleterious to larvae growth, apparently due to a postingestive mechanism. Thus, ectopic expression of TDC1 can allow sufficient tryptamine to accumulate in poplar and tobacco leaf tissue to suppress significantly the growth of insect pests that normally feed on these plants.

  16. Ectomycorrhizal colonization and diversity in relation to tree biomass and nutrition in a plantation of transgenic poplars with modified lignin biosynthesis.

    PubMed

    Danielsen, Lara; Lohaus, Gertrud; Sirrenberg, Anke; Karlovsky, Petr; Bastien, Catherine; Pilate, Gilles; Polle, Andrea

    2013-01-01

    Wood from biomass plantations with fast growing tree species such as poplars can be used as an alternative feedstock for production of biofuels. To facilitate utilization of lignocellulose for saccharification, transgenic poplars with modified or reduced lignin contents may be useful. However, the potential impact of poplars modified in the lignification pathway on ectomycorrhizal (EM) fungi, which play important roles for plant nutrition, is not known. The goal of this study was to investigate EM colonization and community composition in relation to biomass and nutrient status in wildtype (WT, Populus tremula × Populus alba) and transgenic poplar lines with suppressed activities of cinnamyl alcohol dehydrogenase, caffeate/5-hydroxyferulate O-methyltransferase, and cinnamoyl-CoA reductase in a biomass plantation. In different one-year-old poplar lines EM colonization varied from 58% to 86%, but the EM community composition of WT and transgenic poplars were indistinguishable. After two years, the colonization rate of all lines was increased to about 100%, but separation of EM communities between distinct transgenic poplar genotypes was observed. The differentiation of the EM assemblages was similar to that found between different genotypes of commercial clones of Populus × euramericana. The transgenic poplars exhibited significant growth and nutrient element differences in wood, with generally higher nutrient accumulation in stems of genotypes with lower than in those with higher biomass. A general linear mixed model simulated biomass of one-year-old poplar stems with high accuracy (adjusted R(2) = 97%) by two factors: EM colonization and inverse wood N concentration. These results imply a link between N allocation and EM colonization, which may be crucial for wood production in the establishment phase of poplar biomass plantations. Our data further support that multiple poplar genotypes regardless whether generated by transgenic approaches or conventional

  17. Ectomycorrhizal Colonization and Diversity in Relation to Tree Biomass and Nutrition in a Plantation of Transgenic Poplars with Modified Lignin Biosynthesis

    PubMed Central

    Danielsen, Lara; Lohaus, Gertrud; Sirrenberg, Anke; Karlovsky, Petr; Bastien, Catherine; Pilate, Gilles; Polle, Andrea

    2013-01-01

    Wood from biomass plantations with fast growing tree species such as poplars can be used as an alternative feedstock for production of biofuels. To facilitate utilization of lignocellulose for saccharification, transgenic poplars with modified or reduced lignin contents may be useful. However, the potential impact of poplars modified in the lignification pathway on ectomycorrhizal (EM) fungi, which play important roles for plant nutrition, is not known. The goal of this study was to investigate EM colonization and community composition in relation to biomass and nutrient status in wildtype (WT, Populus tremula × Populus alba) and transgenic poplar lines with suppressed activities of cinnamyl alcohol dehydrogenase, caffeate/5-hydroxyferulate O-methyltransferase, and cinnamoyl-CoA reductase in a biomass plantation. In different one-year-old poplar lines EM colonization varied from 58% to 86%, but the EM community composition of WT and transgenic poplars were indistinguishable. After two years, the colonization rate of all lines was increased to about 100%, but separation of EM communities between distinct transgenic poplar genotypes was observed. The differentiation of the EM assemblages was similar to that found between different genotypes of commercial clones of Populus × euramericana. The transgenic poplars exhibited significant growth and nutrient element differences in wood, with generally higher nutrient accumulation in stems of genotypes with lower than in those with higher biomass. A general linear mixed model simulated biomass of one-year-old poplar stems with high accuracy (adjusted R2 = 97%) by two factors: EM colonization and inverse wood N concentration. These results imply a link between N allocation and EM colonization, which may be crucial for wood production in the establishment phase of poplar biomass plantations. Our data further support that multiple poplar genotypes regardless whether generated by transgenic approaches or conventional

  18. Transcriptome sequencing of transgenic poplar (Populus × euramericana 'Guariento') expressing multiple resistance genes

    PubMed Central

    2014-01-01

    Background Transgenic poplar (Populus × euramericana 'Guariento') plants harboring five exogenous, stress-related genes exhibit increased tolerance to multiple stresses including drought, salt, waterlogging, and insect feeding, but the complex mechanisms underlying stress tolerance in these plants have not been elucidated. Here, we analyzed the differences in the transcriptomes of the transgenic poplar line D5-20 and the non-transgenic line D5-0 using high-throughput transcriptome sequencing techniques and elucidated the functions of the differentially expressed genes using various functional annotation methods. Results We generated 11.80 Gb of sequencing data containing 63, 430, 901 sequences, with an average length of 200 bp. The processed sequences were mapped to reference genome sequences of Populus trichocarpa. An average of 62.30% and 61.48% sequences could be aligned with the reference genomes for D5-20 and D5-0, respectively. We detected 11,352 (D5-20) and 11,372 expressed genes (D5-0), 7,624 (56.61%; D5-20) and 7,453 (65.54%; D5-0) of which could be functionally annotated. A total of 782 differentially expressed genes in D5-20 were identified compared with D5-0, including 628 up-regulated and 154 down-regulated genes. In addition, 196 genes with putative functions related to stress responses were also annotated. Gene Ontology (GO) analysis revealed that 346 differentially expressed genes are mainly involved in 67 biological functions, such as DNA binding and nucleus. KEGG annotation revealed that 36 genes (21 up-regulated and 15 down-regulated) were enriched in 51 biological pathways, 9 of which are linked to glucose metabolism. KOG functional classification revealed that 475 genes were enriched in 23 types of KOG functions. Conclusion These results suggest that the transferred exogenous genes altered the expression of stress (biotic and abiotic) response genes, which were distributed in different metabolic pathways and were linked to some extent. Our

  19. An Exploratory Study on the Junior Brixton Spatial Rule Attainment Test in 6- to 8-Year-Olds

    ERIC Educational Resources Information Center

    Senturk, Nilay; Yeniceri, Nur; Alp, I. Ercan; Altan-Atalay, Ayse

    2014-01-01

    This study explored the Junior Brixton Test (JBT), an executive function (EF) measure for children, in comparison to the Wisconsin Card Sorting Test (WCST) in a sample of 6- to 8-year-olds, all attending the first 2 years of elementary school. Factor analyses indicated two main domains in both measures, namely concept formation and cognitive…

  20. The Effect of Action Valence and Race on 3- to 8-Year-Old Children's Social Cognitive Judgments

    ERIC Educational Resources Information Center

    Arterberry, Martha E.; Hughes, Brittany C.; Mejia, Barbara

    2015-01-01

    The present study investigated children's judgments of actions as a function of the valence of the action and the race of the actor. Three- to 8-year-old children were read an illustrated storybook in which 1 character did not share (a negatively valenced action) and the other character was helpful (a positively valenced action). The race of the…

  1. Successful crossings with early flowering transgenic poplar: interspecific crossings, but not transgenesis, promoted aberrant phenotypes in offspring.

    PubMed

    Hoenicka, Hans; Lehnhardt, Denise; Nilsson, Ove; Hanelt, Dieter; Fladung, Matthias

    2014-10-01

    In forest tree species, the reproductive phase is reached only after many years or even decades of juvenile growth. Different early flowering systems based on the genetic transfer of heat-shock promoter driven flowering-time genes have been proposed for poplar; however, no fertile flowers were reported until now. Here, we studied flower and pollen development in both HSP::AtFT and wild-type male poplar in detail and developed an optimized heat treatment protocol to obtain fertile HSP::AtFT flowers. Anthers from HSP::AtFT poplar flowers containing fertile pollen grains showed arrested development in stage 12 instead of reaching phase 13 as do wild-type flowers. Pollen grains could be isolated under the binocular microscope and were used for intra- and interspecific crossings with wild-type poplar. F1-seedlings segregating the HSP::AtFT gene construct according to Mendelian laws were obtained. A comparison between intra- and interspecific crossings revealed that genetic transformation had no detrimental effects on F1-seedlings. However, interspecific crossings, a broadly accepted breeding method, produced 47% seedlings with an aberrant phenotype. The early flowering system presented in this study opens new possibilities for accelerating breeding of poplar and other forest tree species. Fast breeding and the selection of transgene-free plants, once the breeding process is concluded, can represent an attractive alternative even under very restrictive regulations. PMID:24975279

  2. Transgenic poplar expressing codA exhibits enhanced growth and abiotic stress tolerance.

    PubMed

    Ke, Qingbo; Wang, Zhi; Ji, Chang Yoon; Jeong, Jae Cheol; Lee, Haeng-Soon; Li, Hongbing; Xu, Bingcheng; Deng, Xiping; Kwak, Sang-Soo

    2016-03-01

    Glycine betaine (GB), a compatible solute, effectively stabilizes the structure and function of macromolecules and enhances abiotic stress tolerance in plants. We generated transgenic poplar plants (Populus alba × Populus glandulosa) expressing a bacterial choline oxidase (codA) gene under the control of the oxidative stress-inducible SWPA2 promoter (referred to as SC plants). Among the 13 SC plants generated, three lines (SC4, SC14 and SC21) were established based on codA transcript levels, tolerance to methyl viologen-mediated oxidative stress and Southern blot analysis. Growth was better in SC plants than in non-transgenic (NT) plants, which was related to elevated transcript levels of auxin-response genes. SC plants accumulated higher levels of GB under oxidative stress compared to the NT plants. In addition, SC plants exhibited increased tolerance to drought and salt stress, which was associated with increased efficiency of photosystem II activity. Finally, SC plants maintained lower levels of ion leakage and reactive oxygen species under cold stress compared to the NT plants. These observations suggest that SC plants might be useful for reforestation on global marginal lands, including desertification and reclaimed areas. PMID:26795732

  3. Chiropractic Care of an 8-Year-Old Girl With Nonorganic, Primary Nocturnal Enuresis: A Case Report

    PubMed Central

    Instebø, Eigil; Lystad, Reidar P

    2016-01-01

    Objective The purpose of this case report is to describe the chiropractic management of an 8-year-old girl with nonorganic, primary nocturnal enuresis. Clinical Features An 8-year-old female patient presented to a chiropractic clinic with persistent nighttime bedwetting. The patient experienced enuresis, on average, 7 nights per week. The patient presented with no other comorbidities or complaints, such as low back or pelvic pain. Intervention and Outcomes Chiropractic treatment included high-velocity, low-amplitude manipulation of the left sacroiliac joint over 3 visits. Follow-up at 3 months revealed only 3 subsequent episodes of nocturnal enuresis. Conclusion This patient reported the resolution of nonorganic, primary nocturnal enuresis after receiving a series of side-posture chiropractic manipulations of the left sacroiliac joint. PMID:27069432

  4. Combined expression of antimicrobial genes (Bbchit1 and LJAMP2) in transgenic poplar enhances resistance to fungal pathogens.

    PubMed

    Huang, Yan; Liu, Hong; Jia, Zhichun; Fang, Qing; Luo, Keming

    2012-10-01

    Populus species are susceptible to infection by microbial pathogens that severely affect their growth and substantially decrease their economic value. In this study, two pathogenesis-related protein genes consisting of Beauveria bassiana chitinase (Bbchit1) and motherwort lipid-transfer protein (LJAMP2) were introduced into Chinese white poplar (Populus tomentosa Carr.) via Agrobacterium-mediated transformation using the hygromycin (hyg) and neomycin phosphotransferase (NPTII) genes as selectable markers, respectively. Polymerase chain reaction analysis confirmed the stable integration of transgenes in the genome of transgenic plants. In vitro assays showed that inhibitory activity against the fungal pathogen Alternaria alternata (Fr.) Keissler was evident from the crude leaf extracts from transgenic plants. Importantly, the double-transgenic plants exhibited significantly higher resistance to the pathogen than either of the single-gene transformants and wild-type plants when inoculated with A. alternata. The level of disease reduction in double-transgenic lines was between 82 and 95%, whereas that of single-gene transformants carrying either LJAMP2 or Bbchit1 was between 65 and 89%. These results indicated that the combined expression of the LJAMP2 and Bbchit-1 genes could significantly enhance resistance to necrotrophic fungal pathogens in poplar.

  5. Chronic inflammatory demyelinating polyradiculoneuropathy, in an 8-year-old girl, complicated by deafness and kidney fibrosis.

    PubMed

    Stojanovic, Vesna D; Doronjski, Aleksandra R; Spasojevic, Slobodan D; Pavlovic, Vesna S; Nikolic, Marko M; Kovacevic, Branka B

    2009-08-01

    Based on case history and clinical and electrophysiological examinations, the authors report on a case of an 8-year-old girl who was diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy. The disease was complicated by deafness and kidney fibrosis. During treatment with methylprednisolone and intravenous immunoglobulin, followed by mycophenolate mofetil, prompt improvement of neurological findings occurred. The improvement of hearing was poor. Because the pathogenesis of chronic inflammatory demyelinating polyradiculoneuropathy has still not been clear, and on the grounds of several cases of chronic inflammatory demyelinating polyradiculoneuropathy conjoined with the kidney disease described in literature (glomerulopathy, interstitial nephritis), every patient with chronic inflammatory demyelinating polyradiculoneuropathy needs to undergo the urinalyses.

  6. Choroidal neovascularisation as an unusual ophthalmic manifestation of cat-scratch disease in an 8-year-old girl.

    PubMed

    Latanza, L; Viscogliosi, F; Solimeo, A; Calabrò, F; De Angelis, V; De Rosa, P

    2015-10-01

    To report the first case of choroidal neovascularisation (CNV) that appeared during the primary Bartonella henselae infection in an 8-year-old girl. An 8-year-old girl was referred to our clinic complaining of a central scotoma in the right eye. Fundus examination revealed a bilateral disc oedema and in the right eye neuroretinitis with macular star and CNV, which was confirmed by fluorescein angiography. The optical coherence tomography revealed the presence of macular serous retinal detachment. Laboratory analysis showed rising IgM and IgG titres for B. henselae. Cat-scratch disease was diagnosed, and an 8-week treatment with azithromycin was initiated. In addition, an intravitreal injection of ranibizumab was performed in the right eye to treat the CNV. A month later, we decided to administer a systemic antibiotic again for an additional 5 months, due to the persistence of papillitis. Cat-scratch disease should be considered among the different causes of inflammatory CNV secondary to infectious uveitis. Our case was the first described in the literature in which a CNV appeared during the primary infection and not as a later complication. The combination of systemic antibiotic treatment with intravitreal anti-VEGF therapy was a successful choice because it allowed us to obtain the complete resolution of neuroretinitis, associated with the scarring of the choroidal neovascular membrane, with a final visual acuity of 20/20 in both eyes.

  7. Expression of Multiple Resistance Genes Enhances Tolerance to Environmental Stressors in Transgenic Poplar (Populus × euramericana ‘Guariento’)

    PubMed Central

    Su, Xiaohua; Chu, Yanguang; Li, Huan; Hou, Yingjie; Zhang, Bingyu; Huang, Qinjun; Hu, Zanmin; Huang, Rongfeng; Tian, Yingchuan

    2011-01-01

    Commercial and non-commercial plants face a variety of environmental stressors that often cannot be controlled. In this study, transgenic hybrid poplar (Populus × euramericana ‘Guariento’) harboring five effector genes (vgb, SacB, JERF36, BtCry3A and OC-I) were subjected to drought, salinity, waterlogging and insect stressors in greenhouse or laboratory conditions. Field trials were also conducted to investigate long-term effects of transgenic trees on insects and salt tolerance in the transformants. In greenhouse studies, two transgenic lines D5-20 and D5-21 showed improved growth, as evidenced by greater height and basal diameter increments and total biomass relative to the control plants after drought or salt stress treatments. The improved tolerance to drought and salt was primarily attributed to greater instantaneous water use efficiency (WUEi) in the transgenic trees. The chlorophyll concentrations tended to be higher in the transgenic lines under drought or saline conditions. Transformed trees in drought conditions accumulated more fructan and proline and had increased Fv/Fm ratios (maximum quantum yield of photosystem II) under waterlogging stress. Insect-feeding assays in the laboratory revealed a higher total mortality rate and lower exuviation index of leaf beetle [Plagiodera versicolora (Laicharting)] larvae fed with D5-21 leaves, suggesting enhanced insect resistance in the transgenic poplar. In field trials, the dominance of targeted insects on 2-year-old D5-21 transgenic trees was substantially lower than that of the controls, indicating enhanced resistance to Coleoptera. The average height and DBH (diameter at breast height) of 2.5-year-old transgenic trees growing in naturally saline soil were 3.80% and 4.12% greater than those of the control trees, but these increases were not significant. These results suggested that multiple stress-resistance properties in important crop tree species could be simultaneously improved, although additional

  8. Expression of multiple resistance genes enhances tolerance to environmental stressors in transgenic poplar (Populus × euramericana 'Guariento').

    PubMed

    Su, Xiaohua; Chu, Yanguang; Li, Huan; Hou, Yingjie; Zhang, Bingyu; Huang, Qinjun; Hu, Zanmin; Huang, Rongfeng; Tian, Yingchuan

    2011-01-01

    Commercial and non-commercial plants face a variety of environmental stressors that often cannot be controlled. In this study, transgenic hybrid poplar (Populus × euramericana 'Guariento') harboring five effector genes (vgb, SacB, JERF36, BtCry3A and OC-I) were subjected to drought, salinity, waterlogging and insect stressors in greenhouse or laboratory conditions. Field trials were also conducted to investigate long-term effects of transgenic trees on insects and salt tolerance in the transformants. In greenhouse studies, two transgenic lines D5-20 and D5-21 showed improved growth, as evidenced by greater height and basal diameter increments and total biomass relative to the control plants after drought or salt stress treatments. The improved tolerance to drought and salt was primarily attributed to greater instantaneous water use efficiency (WUEi) in the transgenic trees. The chlorophyll concentrations tended to be higher in the transgenic lines under drought or saline conditions. Transformed trees in drought conditions accumulated more fructan and proline and had increased Fv/Fm ratios (maximum quantum yield of photosystem II) under waterlogging stress. Insect-feeding assays in the laboratory revealed a higher total mortality rate and lower exuviation index of leaf beetle [Plagiodera versicolora (Laicharting)] larvae fed with D5-21 leaves, suggesting enhanced insect resistance in the transgenic poplar. In field trials, the dominance of targeted insects on 2-year-old D5-21 transgenic trees was substantially lower than that of the controls, indicating enhanced resistance to Coleoptera. The average height and DBH (diameter at breast height) of 2.5-year-old transgenic trees growing in naturally saline soil were 3.80% and 4.12% greater than those of the control trees, but these increases were not significant. These results suggested that multiple stress-resistance properties in important crop tree species could be simultaneously improved, although additional

  9. The end-state comfort effect in 3- to 8-year-old children in two object manipulation tasks.

    PubMed

    Knudsen, Birgit; Henning, Anne; Wunsch, Kathrin; Weigelt, Matthias; Aschersleben, Gisa

    2012-01-01

    The aim of the study was to compare 3- to 8-year-old children's propensity to anticipate a comfortable hand posture at the end of a grasping movement (end-state comfort effect) between two different object manipulation tasks, the bar-transport task, and the overturned-glass task. In the bar-transport task, participants were asked to insert a vertically positioned bar into a small opening of a box. In the overturned-glass task, participants were asked to put an overturned-glass right-side-up on a coaster. Half of the participants experienced action effects (lights) as a consequence of their movements (AE groups), while the other half of the participants did not (No-AE groups). While there was no difference between the AE and No-AE groups, end-state comfort performance differed across age as well as between tasks. Results revealed a significant increase in end-state comfort performance in the bar-transport task from 13% in the 3-year-olds to 94% in the 8-year-olds. Interestingly, the number of children grasping the bar according to end-state comfort doubled from 3 to 4 years and from 4 to 5 years of age. In the overturned-glass task an increase in end-state comfort performance from already 63% in the 3-year-olds to 100% in the 8-year-olds was significant as well. When comparing end-state comfort performance across tasks, results showed that 3- and 4-year-old children were better at manipulating the glass as compared to manipulating the bar, most probably, because children are more familiar with manipulating glasses. Together, these results suggest that preschool years are an important period for the development of motor planning in which the familiarity with the object involved in the task plays a significant role in children's ability to plan their movements according to end-state comfort.

  10. Transgenic poplar expressing Arabidopsis YUCCA6 exhibits auxin-overproduction phenotypes and increased tolerance to abiotic stress.

    PubMed

    Ke, Qingbo; Wang, Zhi; Ji, Chang Yoon; Jeong, Jae Cheol; Lee, Haeng-Soon; Li, Hongbing; Xu, Bingcheng; Deng, Xiping; Kwak, Sang-Soo

    2015-09-01

    YUCCA6, a member of the YUCCA family of flavin monooxygenase-like proteins, is involved in the tryptophan-dependent IAA biosynthesis pathway and responses to environmental cues in Arabidopsis. However, little is known about the role of the YUCCA pathway in auxin biosynthesis in poplar. Here, we generated transgenic poplar (Populus alba × P. glandulosa) expressing the Arabidopsis YUCCA6 gene under the control of the oxidative stress-inducible SWPA2 promoter (referred to as SY plants). Three SY lines (SY7, SY12 and SY20) were selected based on the levels of AtYUCCA6 transcript. SY plants displayed auxin-overproduction morphological phenotypes, such as rapid shoot growth and retarded main root development with increased root hair formation. In addition, SY plants had higher levels of free IAA and early auxin-response gene transcripts. SY plants exhibited tolerance to drought stress, which was associated with reduced levels of reactive oxygen species. Furthermore, SY plants showed delayed hormone- and dark-induced senescence in detached leaves due to higher photosystem II efficiency and less membrane permeability. These results suggest that the conserved IAA biosynthesis pathway mediated by YUCCA family members exists in poplar. PMID:25980973

  11. Relationships of objectively measured physical activity and sleep with BMI and academic outcomes in 8-year-old children.

    PubMed

    Harrington, Susan Ann

    2013-05-01

    Current guidelines in place for sleep and physical activity in childhood are the result of data collected in the form of self-reports. Exact measurement of activity dimensions and sleep characteristics are essential. The purpose of clearly established parameters is for the intent of verifying health outcomes and evaluating interventions. The purpose of this research was to determine the relationships between the objective dimensions of physical activity, sleep, weight status, academic achievement, and academic behavior. This cross-sectional correlational descriptive design examined the activity and sleep patterns continuously for 24 hours/7 days with triaxial accelerometers in a low income African American sample of 8-year-olds. A qualitative component gathered additional identifiers. This sample was overweight/obese, inactive, and sleep-deprived. Moderate-vigorous activity was correlated with reading scores. Confirmed in this research was the association between sleep duration, physical activity intensities, and academics. Positive health outcomes in children are endorsed by an energy balance.

  12. Acute chemotherapy-induced cardiomyopathy treated with intracorporeal left ventricular assist device in an 8-year-old child.

    PubMed

    Schweiger, Martin; Dave, Hitendu; Lemme, Frithjof; Cavigelli-Brunner, Anna; Romanchenko, Olga; Heineking, Bea; Hofmann, Michael; Bürki, Chrstoph; Stiasny, Brian; Hübler, Michael

    2013-01-01

    Evolution of ventricular assist devices (VADs) leading to miniaturization has made intracorporeal implantation in children feasible. Ventricular assist device therapy for anthracycline-induced cardiomyopathy (CMP) in adults has been reported. We report the case of an 8-year-old child (body surface area 0.97 m) presenting with anthracycline-induced CMP being successfully treated with an intracorporeal left ventricular assist device (LVAD) as a bridge to candidacy/recovery. We present our institutional algorithm, which advises intracorporeal LVAD implantation for long-term ventricular assist, in children with a body surface area >0.6 m. Advantages are better mobilization and the possibility to discharge home, leading to enhanced quality of life.

  13. Seizures triggered by July 4th fireworks in an 8-year-old girl with perinatal stroke.

    PubMed

    Brosch, Jared R; Golomb, Meredith R

    2011-05-01

    Warnings regarding fireworks displays as a possible seizure-producing stimulus have been around for several years, but there is a lack of well-documented cases. This case describes photic- and/or pattern-induced seizures that appeared to be triggered by July 4 fireworks. This 8-year-old girl with hemiplegic cerebral palsy and known seizure disorder because of perinatal right middle cerebral artery stroke had a cluster of seizures within minutes of the onset of a professional fireworks display. The seizures stopped when the child's eyes were covered and she was taken away from the scene. The importance of photic- and pattern-induced seizures in children is discussed.

  14. Occlusal and oral health status of a group of 3-8-year-old South African black children.

    PubMed

    Coetzee, C E; Wiltshire, W A

    2000-05-01

    This study determined the oral health status of a group of 3-8-year-old South African black children, comprising a total of 214 children from the townships of Garankuwa, Shosanguwe, Mabopane, Hebron and Erasmus who attended a school in Akasia, Greater Pretoria Metropolitan Substructure. The decayed, missing and filled teeth (dmft), oral hygiene status, dental IQ and malocclusion status were determined. The study found that the children's oral health status and occlusal status were unacceptable. The level of their dental IQ scores was low, their oral hygiene poor, and they were in urgent need of primary and secondary dental care. In addition they were in need of both preventive and interceptive orthodontic care. A national strategy to address primary dental health care is recommended. PMID:12608266

  15. A case of cerebral salt-wasting syndrome associated with aseptic meningitis in an 8-year-old boy.

    PubMed

    Inatomi, Jun; Yokoyama, Yoshiki; Sekine, Takashi; Igarashi, Takashi

    2008-04-01

    Cerebral salt-wasting syndrome is a disorder in which excessive natriuresis and subsequent hyponatremic dehydration occur in patients with intracranial diseases. Cerebral salt-wasting syndrome often develops in patients with severe neurosurgical disorders, such as hydrocephalus, cerebral infarction, and tuberculous meningitis. Here, we report on the case of an 8-year-old boy with cerebral salt-wasting syndrome associated with aseptic meningitis. He showed mild developmental retardation and had a history of convulsion. Four days after his admission, cerebral salt-wasting syndrome abruptly started: natriuresis and hyponatremia gradually improved over 10 days. To the best of our knowledge, this is the first report on cerebral salt-wasting syndrome associated with clinically benign aseptic meningitis.

  16. Gonadotropin-dependent precocious puberty in an 8-year-old boy with leydig cell testicular tumor.

    PubMed

    Santos-Silva, Rita; Bonito-Vítor, Artur; Campos, Miguel; Fontoura, Manuel

    2014-01-01

    Leydig cell testicular tumors are very rare in children. They can present as gonadotropin-independent precocious puberty due to excess androgen secretion. We report the case of an 8-year-old boy with isosexual precocity whose hormonal investigation showed luteinizing hormone-independent testosterone hypersecretion. Although no palpable mass was present, scrotal ultrasound revealed a testicular tumor. Testis-sparing tumor resection was performed and the histopathology analysis showed a Leydig cell tumor. After surgery the testosterone levels remained high and further examination showed gonadotropin-dependent precocious puberty, which is believed to be likely caused by the activation of the hypothalamic-pituitary axis due to a long-term exposition to sex steroids. He is currently being treated with a long-acting gonadotropin-releasing hormone analog and the process of sexual precocity has until now been suppressed.

  17. The impact of doll style of dress and familiarity on body dissatisfaction in 6- to 8-year-old girls.

    PubMed

    Jellinek, Rebecca D; Myers, Taryn A; Keller, Kathleen L

    2016-09-01

    We tested the impact of exposure to dolls of different body types and wardrobes on girls' body dissatisfaction. In Study 1, 112 girls (6 to 8 years old) were randomized to one of four conditions: thin (Barbie™) or full-figured (Tracy™) dolls dressed in a swimsuit or modest clothing. In Study 2, a different cohort of girls (n=112) was exposed to one of four conditions containing unfamiliar dolls of different body size (thin vs. full-figured) and dress (modest vs. swimsuit). In both studies, girls who played with thin dolls experienced higher body size discrepancies than girls who played with full-figured dolls. Girls who played with full-figured dolls showed less body dissatisfaction after doll exposure compared to girls who played with thin dolls. Playing with unrealistically thin dolls may encourage motivation for a thinner shape in young girls.

  18. Dietary Patterns and Their Socioeconomic and Behavioral Determinants in 6- to 8-Year-Old Portuguese Children.

    PubMed

    Rodrigues, D; Muc, M; Rodrigues, P R M; Pinto, A Mota; Padez, C

    2016-01-01

    Adherence to a healthier diet is declining, with children consuming more saturated fats and simple carbohydrates. Factors influencing this choice were studied using a cross-sectional study with children (6 to 8 years old) living in Coimbra. Socioeconomic and behavioral factors were obtained from the parents. Dietary patterns of 1,063 children were identified: Mediterranean (MedDiet), saturated fats (SFatDiet), and base of Portuguese diet (BPDiet). Their relationship with socioeconomic and behavioral determinants was analyzed. SES determined strongly the dietary choices with lower SES being associated with higher consumption of SFatDiet and higher SES with BPDiet. Worse diet quality was shown to coexist with other unhealthy behaviors. PMID:27398743

  19. The impact of doll style of dress and familiarity on body dissatisfaction in 6- to 8-year-old girls.

    PubMed

    Jellinek, Rebecca D; Myers, Taryn A; Keller, Kathleen L

    2016-09-01

    We tested the impact of exposure to dolls of different body types and wardrobes on girls' body dissatisfaction. In Study 1, 112 girls (6 to 8 years old) were randomized to one of four conditions: thin (Barbie™) or full-figured (Tracy™) dolls dressed in a swimsuit or modest clothing. In Study 2, a different cohort of girls (n=112) was exposed to one of four conditions containing unfamiliar dolls of different body size (thin vs. full-figured) and dress (modest vs. swimsuit). In both studies, girls who played with thin dolls experienced higher body size discrepancies than girls who played with full-figured dolls. Girls who played with full-figured dolls showed less body dissatisfaction after doll exposure compared to girls who played with thin dolls. Playing with unrealistically thin dolls may encourage motivation for a thinner shape in young girls. PMID:27344610

  20. Indicators of fetal growth do not independently predict blood pressure in 8-year-old Australians: a prospective cohort study.

    PubMed

    Burke, Valerie; Beilin, Lawrie J; Blake, Kevin V; Doherty, Dorota; Kendall, Garth E; Newnham, John P; Landau, Louis I; Stanley, Fiona J

    2004-02-01

    Inverse associations between size at birth and blood pressure (BP) in later life are commonly statistically significant only after adjustment for current size, consistent with change in size as the determinant. Few studies have been prospective or have included a range of potential confounders. Using regression models, including maternal and demographic variables, we examined associations between size at birth and BP in Australian children followed from week 16 of gestation to the age of 8 years. BP measurements were available from 1417 children born after 37 weeks gestation without congenital abnormalities. In models adjusted only for sex, the birthweight (BW), birth length, ponderal index, head circumference, chest circumference, abdominal girth, mid-arm circumference, triceps skinfold, placental weight, or BW/placental weight ratio did not significantly predict SBP in 8-year-olds. With adjustment for current size, associations were inverse but not statistically significant (regression coefficients: BW, -1.11; 95% confidence limits [CL], -2.22, 0.01; birth length, -0.25; 95% CL, -0.52, 0.24) and remained nonsignificant after adjustment for confounders. Current weight, height, or body mass index significantly predicted SBP and DBP (P<0.001) with differences of 8/4 mm Hg between upper and lower quartiles; effects were similar in infants with lower and higher BW. These findings are consistent with postnatal change in size as the major determinant of BP in 8-year-olds and are important in the context of the worldwide "epidemic" of obesity in childhood as a likely precursor of increasing rates of hypertension in adults. PMID:14718353

  1. Lead uptake increases drought tolerance of wild type and transgenic poplar (Populus tremula x P. alba) overexpressing gsh 1.

    PubMed

    Samuilov, Sladjana; Lang, Friedericke; Djukic, Matilda; Djunisijevic-Bojovic, Danijela; Rennenberg, Heinz

    2016-09-01

    Growth and development of plants largely depends on their adaptation ability in a changing climate. This is particularly true on heavy metal contaminated soils, but the interaction of heavy metal stress and climate on plant performance has not been intensively investigated. The aim of the present study was to elucidate if transgenic poplars (Populus tremula x P. alba) with enhanced glutathione content possess an enhanced tolerance to drought and lead (Pb) exposure (single and in combination) and if they are good candidates for phytoremediation of Pb contaminated soil. Lead exposure reduced growth and biomass accumulation only in above-ground tissue of wild type poplar, although most of lead accumulated in the roots. Drought caused a decline of the water content rather than reduced biomass production, while Pb counteracted this decline in the combined exposure. Apparently, metals such as Pb possess a protective function against drought, because they interact with abscisic acid dependent stomatal closure. Lead exposure decreased while drought increased glutathione content in leaves of both plant types. Lead accumulation was higher in the roots of transgenic plants, presumably as a result of chelation by glutathione. Water deprivation enhanced Pb accumulation in the roots, but Pb was subject to leakage out of the roots after re-watering. Transgenic plants showed better adaptation under mild drought plus Pb exposure partially due to improved glutathione synthesis. However, the transgenic plants cannot be considered as a good candidate for phytoremediation of Pb, due to its small translocation to the shoots and its leakage out of the roots upon re-watering. PMID:27396669

  2. Overexpression of TaLEA gene from Tamarix androssowii improves salt and drought tolerance in transgenic poplar (Populus simonii × P. nigra).

    PubMed

    Gao, Weidong; Bai, Shuang; Li, Qingmei; Gao, Caiqiu; Liu, Guifeng; Li, Guangde; Tan, Feili

    2013-01-01

    Late embryogenesis abundant (LEA) genes were confirmed to confer resistance to drought and water deficiency. An LEA gene from Tamarixandrossowii (named TaLEA) was transformed into Xiaohei poplar (Populussimonii × P. nigra) via Agrobacterium. Twenty-five independent transgenic lines were obtained that were resistant to kanamycin, and 11 transgenic lines were randomly selected for further analysis. The polymerase chain reaction (PCR) and ribonucleic acid (RNA) gel blot indicated that the TaLEA gene had been integrated into the poplar genome. The height growth rate, malondialdehyde (MDA) content, relative electrolyte leakage and damages due to salt or drought to transgenic and non-transgenic plants were compared under salt and drought stress conditions. The results showed that the constitutive expression of the TaLEA gene in transgenic poplars could induce an increase in height growth rate and a decrease in number and severity of wilted leaves under the salt and drought stresses. The MDA content and relative electrolyte leakage in transgenic lines under salt and drought stresses were significantly lower compared to those in non-transgenic plants, indicating that the TaLEA gene may enhance salt and drought tolerance by protecting cell membranes from damage. Moreover, amongst the lines analyzed for stress tolerance, the transgenic line 11 (T11) showed the highest tolerance levels under both salinity and drought stress conditions. These results indicated that the TaLEA gene could be a salt and drought tolerance candidate gene and could confer a broad spectrum of tolerance under abiotic stresses in poplars.

  3. No childhood development of viewpoint-invariant face recognition: evidence from 8-year-olds and adults.

    PubMed

    Crookes, Kate; Robbins, Rachel A

    2014-10-01

    Performance on laboratory face tasks improves across childhood, not reaching adult levels until adolescence. Debate surrounds the source of this development, with recent reviews suggesting that underlying face processing mechanisms are mature early in childhood and that the improvement seen on experimental tasks instead results from general cognitive/perceptual development. One face processing mechanism that has been argued to develop slowly is the ability to encode faces in a view-invariant manner (i.e., allowing recognition across changes in viewpoint). However, many previous studies have not controlled for general cognitive factors. In the current study, 8-year-olds and adults performed a recognition memory task with two study-test viewpoint conditions: same view (study front view, test front view) and change view (study front view, test three-quarter view). To allow quantitative comparison between children and adults, performance in the same view condition was matched across the groups by increasing the learning set size for adults. Results showed poorer memory in the change view condition than in the same view condition for both adults and children. Importantly, there was no quantitative difference between children and adults in the size of decrement in memory performance resulting from a change in viewpoint. This finding adds to growing evidence that face processing mechanisms are mature early in childhood.

  4. Inter-relationships among physical activity, body fat, and motor performance in 6- to 8-year-old Danish children.

    PubMed

    Morrison, Kyle M; Bugge, Anna; El-Naaman, Bianca; Eisenmann, Joey C; Froberg, Karsten; Pfeiffer, Karin A; Andersen, Lars Bo

    2012-05-01

    This study examined the interrelationships among physical activity (PA), percent body fat (%BF), and motor performance (MP) in 498 6- to 8-year-old Danish children. PA was assessed by accelerometer, %BF was calculated from skinfolds, and the Koordinations Test für Kinder along with a throwing accuracy test was used to assess MP. PA was not correlated with %BF, but was significantly correlated with MP. The strongest correlations existed between %BF and MP. Low %BF/High PA had higher MP scores compared with High %BF/Low PA, and within the High %BF groups MP was higher in the High PA versus Low PA group. When comparing PA by %BF and MP groups, boys in the Low %BF/High MP had higher PA than both the Low %BF/Low MP and High %BF/Low MP groups. In girls, PA was highest in the High %BF/High MP group. This study highlights the complex interrelationships among PA, %BF, and MP in children and the need to develop fundamental motor skills during childhood.

  5. Limited impact of elevated levels of polyphenol oxidase on tree-feeding caterpillars: assessing individual plant defenses with transgenic poplar.

    PubMed

    Barbehenn, Raymond V; Jones, Christopher P; Yip, Lynn; Tran, Lan; Constabel, C Peter

    2007-11-01

    Polyphenol oxidase (PPO) is commonly believed to function as an effective antiherbivore defense in plants. PPO is induced in plants following herbivory, and insect performance is often negatively correlated with PPO levels. However, induced defenses create numerous changes in plants, and very little work has been done to test the direct effects of PPO on insect herbivores separately from other changes. This study examined the impacts of high levels of PPO on the performance of two species of tree-feeding caterpillars (Lymantria dispar and Orgyia leucostigma) on poplar. Transgenic PPO-overexpressing poplar (Populus tremula x Populus alba) was used as a source of elevated-PPO leaves, thereby controlling for the multiple effects of induction. In addition, the impacts of treating poplar foliage with high levels of purified mushroom PPO were examined on the two caterpillar species. Contrary to expectation, in several cases increased PPO levels had no significant effect on insect consumption or growth rates. Although one of the mechanisms by which PPO is believed to impact herbivores is via increased oxidative stress, the ingestion of large amounts of PPO had little or no effect on semiquinone radical and oxidized protein levels in the gut contents of lymantriid caterpillars. PPO activity in caterpillars is likely limited by the low oxygen and high ascorbate levels commonly found in their gut contents. This study questions whether induced PPO functions as an effective post-ingestive defense against tree-feeding caterpillars, and indicates that controlled, mechanistic studies are needed in other plant-herbivore systems to test for a direct effect of PPO on insect performance.

  6. Green revolution trees: semidwarfism transgenes modify gibberellins, promote root growth, enhance morphological diversity, and reduce competitiveness in hybrid poplar.

    PubMed

    Elias, Ani A; Busov, Victor B; Kosola, Kevin R; Ma, Cathleen; Etherington, Elizabeth; Shevchenko, Olga; Gandhi, Harish; Pearce, David W; Rood, Stewart B; Strauss, Steven H

    2012-10-01

    Semidwarfism has been used extensively in row crops and horticulture to promote yield, reduce lodging, and improve harvest index, and it might have similar benefits for trees for short-rotation forestry or energy plantations, reclamation, phytoremediation, or other applications. We studied the effects of the dominant semidwarfism transgenes GA Insensitive (GAI) and Repressor of GAI-Like, which affect gibberellin (GA) action, and the GA catabolic gene, GA 2-oxidase, in nursery beds and in 2-year-old high-density stands of hybrid poplar (Populus tremula × Populus alba). Twenty-nine traits were analyzed, including measures of growth, morphology, and physiology. Endogenous GA levels were modified in most transgenic events; GA(20) and GA(8), in particular, had strong inverse associations with tree height. Nearly all measured traits varied significantly among genotypes, and several traits interacted with planting density, including aboveground biomass, root-shoot ratio, root fraction, branch angle, and crown depth. Semidwarfism promoted biomass allocation to roots over shoots and substantially increased rooting efficiency with most genes tested. The increased root proportion and increased leaf chlorophyll levels were associated with changes in leaf carbon isotope discrimination, indicating altered water use efficiency. Semidwarf trees had dramatically reduced growth when in direct competition with wild-type trees, supporting the hypothesis that semidwarfism genes could be effective tools to mitigate the spread of exotic, hybrid, and transgenic plants in wild and feral populations.

  7. Fungal soil communities in a young transgenic poplar plantation form a rich reservoir for fungal root communities

    PubMed Central

    Danielsen, L; Thürmer, A; Meinicke, P; Buée, M; Morin, E; Martin, F; Pilate, G; Daniel, R; Polle, A; Reich, M

    2012-01-01

    Fungal communities play a key role in ecosystem functioning. However, only little is known about their composition in plant roots and the soil of biomass plantations. The goal of this study was to analyze fungal biodiversity in their belowground habitats and to gain information on the strategies by which ectomycorrhizal (ECM) fungi form colonies. In a 2-year-old plantation, fungal communities in the soil and roots of three different poplar genotypes (Populus × canescens, wildtype and two transgenic lines with suppressed cinnamyl alcohol dehydrogenase activity) were analyzed by 454 pyrosequencing targeting the rDNA internal transcribed spacer 1 (ITS) region. The results were compared with the dynamics of the root-associated ECM community studied by morphotyping/Sanger sequencing in two subsequent years. Fungal species and family richness in the soil were surprisingly high in this simple plantation ecosystem, with 5944 operational taxonomic units (OTUs) and 186 described fungal families. These findings indicate the importance that fungal species are already available for colonization of plant roots (2399 OTUs and 115 families). The transgenic modification of poplar plants had no influence on fungal root or soil communities. Fungal families and OTUs were more evenly distributed in the soil than in roots, probably as a result of soil plowing before the establishment of the plantation. Saprophytic, pathogenic, and endophytic fungi were the dominating groups in soil, whereas ECMs were dominant in roots (87%). Arbuscular mycorrhizal diversity was higher in soil than in roots. Species richness of the root-associated ECM community, which was low compared with ECM fungi detected by 454 analyses, increased after 1 year. This increase was mainly caused by ECM fungal species already traced in the preceding year in roots. This result supports the priority concept that ECMs present on roots have a competitive advantage over soil-localized ECM fungi. PMID:22957194

  8. Over-expression of gsh1 in the cytosol affects the photosynthetic apparatus and improves the performance of transgenic poplars on heavy metal-contaminated soil.

    PubMed

    Ivanova, L A; Ronzhina, D A; Ivanov, L A; Stroukova, L V; Peuke, A D; Rennenberg, H

    2011-07-01

    Recent studies of transgenic poplars over-expressing the genes gsh1 and gsh2 encoding γ-glutamylcysteine synthetase (γ-ECS) and glutathione synthetase, respectively, provided detailed information on regulation of GSH synthesis, enzymes activities and mRNA expression. In this experiment, we studied quantitative parameters of leaves, assimilating tissues, cells and chloroplasts, mesophyll resistance for CO(2) diffusion, chlorophyll and carbohydrate content in wild-type poplar and transgenic plants over-expressing gsh1 in the cytosol after 3 years of growth in relatively clean (control) or heavy metal-contaminated soil in the field. Over-expression of gsh1 in the cytosol led to a twofold increase of intrafoliar GSH concentration and influenced the photosynthetic apparatus at different levels of organisation, i.e., leaves, photosynthetic cells and chloroplasts. At the control site, transgenic poplars had a twofold smaller total leaf area per plant and a 1.6-fold leaf area per leaf compared to wild-type controls. Annual aboveground biomass gain was reduced by 50% in the transgenic plants. The reduction of leaf area of the transformants was accompanied by a significant decline in total cell number per leaf, indicating suppression of cell division. Over-expression of γ-ECS in the cytosol also caused changes in mesophyll structure, i.e., a 20% decrease in cell and chloroplast number per leaf area, but also an enhanced volume share of chloroplasts and intercellular airspaces in the leaves. Transgenic and wild poplars did not exhibit differences in chlorophyll and carotenoid content of leaves, but transformants had 1.3-fold fewer soluble carbohydrates. Cultivation on contaminated soil caused a reduction of palisade cell volume and chloroplast number, both per cell and leaf area, in wild-type plants but not in transformants. Biomass accumulation of wild-type poplars decreased in contaminated soil by more than 30-fold, whereas transformants showed a twofold decrease

  9. Physical activity and fitness in 8-year-old overweight and normal weight children and their parents

    PubMed Central

    Karppanen, Anna-Kaisa; Ahonen, Sanna-Mari; Tammelin, Tuija; Vanhala, Marja; Korpelainen, Raija

    2012-01-01

    Objectives To compare the physical fitness and physical activity of 8-year-old overweight children (n =53) to normal weight children (n=65), and to determine whether a significant relationship exists between physical activity of parents and their children. Study design A cross-sectional study. Methods A total of 119 children from Northern Finland were recruited for the study. Waist circumference, height, weight and BMI were measured. Physical activity of the children and their parents was determined with self-administered 7-day recall questionnaires (PAQ-C). Physical fitness of the children was evaluated with 7 items of the EUROFIT-test battery (flamingo balance test, plate tapping, sit-and-reach test, sit-ups, bent arm hang and 10×5 shuttle run). Aerobic capacity of the children was tested with 6-minute walking test. Results Overweigh was related to impaired performance in tests requiring muscle endurance, balance, explosive power of lower extremities, upper body strength and endurance, speed and agility in both genders and aerobic capacity in boys. Physical activity levels of overweight boys (2.41 SD 0.72) were lower than their lean counterparts (2.91 SD 0.64, p=0.004); no such difference was observed in girls (2.53 SD 0.64 vs. 2.59 SD 0.68, p=0.741). Physical activity was significantly associated with better performance in several physical fitness tests in boys, but not in girls. Mothers’ physical activity was associated with children's physical activity (r=0.363, p<0.001), but no such association was found between fathers and children (r=0.019, p=0.864). Conclusion This study shows an inverse relationship between excess bodyweight and physical fitness in children. Mother-child relationship of physical activity appeared to be stronger than father-child relationship. Improving physical fitness in children through physical activity might require interventions that are responsive to the ability and needs of overweight children and their families and focus on

  10. Reduced wood stiffness and strength, and altered stem form, in young antisense 4CL transgenic poplars with reduced lignin contents.

    PubMed

    Voelker, Steven L; Lachenbruch, Barbara; Meinzer, Frederick C; Strauss, Steven H

    2011-03-01

    • Reduced lignin content in perennial crops has been sought as a means to improve biomass processability for paper and biofuels production, but it is unclear how this could affect wood properties and tree form. • Here, we studied a nontransgenic control and 14 transgenic events containing an antisense 4-coumarate:coenzyme A ligase (4CL) to discern the consequences of lignin reduction in poplar (Populus sp.). During the second year of growth, trees were grown either free-standing in a field trial or affixed to stakes in a glasshouse. • Reductions in lignin of up to 40% gave comparable losses in wood strength and stiffness. This occurred despite the fact that low-lignin trees had a similar wood density and up to three-fold more tension wood. In free-standing and staked trees, the control line had twice the height for a given diameter as did low-lignin trees. Staked trees had twice the height for a given diameter as free-standing trees in the field, but did not differ in wood stiffness. • Variation in tree morphogenesis appears to be governed by lignin x environment interactions mediated by stresses exerted on developing cells. Therefore our results underline the importance of field studies for assessing the performance of transgenic trees with modified wood properties.

  11. Functional repression of PtSND2 represses growth and development by disturbing auxin biosynthesis, transport and signaling in transgenic poplar.

    PubMed

    Wang, Haihai; Tang, Renjie; Wang, Cuiting; Qi, Qi; Gai, Ying; Jiang, Xiangning; Zhang, Hongxia

    2015-01-01

    Using chimeric repressor silencing technology, we previously reported that functional repression of PtSND2 severely arrested wood formation in transgenic poplar (Populus). Here, we provide further evidence that auxin biosynthesis, transport and signaling were disturbed in these transgenic plants, leading to pleiotropic defects in their growth patterns, including inhibited leaf enlargement and vascular tissue development in the leaf central vein, suppressed cambial growth and fiber elongation in the stem, and arrested growth in the root system. Two transgenic lines, which displayed the most remarkable phenotypic deviation from the wild-type, were selected for detailed studies. In both transgenic lines, expression of genes for auxin biosynthesis, transport and signaling was down-regulated, and indole-3-acetic acid distribution was severely disturbed in the apical buds, leaves, stems and roots of field-grown transgenic plants. Transient transcription dual-luciferase assays of ProPtTYDC2::LUC, ProPttLAX2::LUC and ProPoptrIAA20.2::LUC in poplar protoplasts revealed that expression of auxin-related genes might be regulated by PtSND2 at the transcriptional level. All these results indicate that functional repression of PtSND2 altered auxin biosynthesis, transport and signaling, and thereby disturbed the normal growth and development of transgenic plants.

  12. Functional repression of PtSND2 represses growth and development by disturbing auxin biosynthesis, transport and signaling in transgenic poplar.

    PubMed

    Wang, Haihai; Tang, Renjie; Wang, Cuiting; Qi, Qi; Gai, Ying; Jiang, Xiangning; Zhang, Hongxia

    2015-01-01

    Using chimeric repressor silencing technology, we previously reported that functional repression of PtSND2 severely arrested wood formation in transgenic poplar (Populus). Here, we provide further evidence that auxin biosynthesis, transport and signaling were disturbed in these transgenic plants, leading to pleiotropic defects in their growth patterns, including inhibited leaf enlargement and vascular tissue development in the leaf central vein, suppressed cambial growth and fiber elongation in the stem, and arrested growth in the root system. Two transgenic lines, which displayed the most remarkable phenotypic deviation from the wild-type, were selected for detailed studies. In both transgenic lines, expression of genes for auxin biosynthesis, transport and signaling was down-regulated, and indole-3-acetic acid distribution was severely disturbed in the apical buds, leaves, stems and roots of field-grown transgenic plants. Transient transcription dual-luciferase assays of ProPtTYDC2::LUC, ProPttLAX2::LUC and ProPoptrIAA20.2::LUC in poplar protoplasts revealed that expression of auxin-related genes might be regulated by PtSND2 at the transcriptional level. All these results indicate that functional repression of PtSND2 altered auxin biosynthesis, transport and signaling, and thereby disturbed the normal growth and development of transgenic plants. PMID:25516528

  13. Response of the gypsy moth, Lymantria dispar to transgenic poplar, Populus simonii x P. nigra, expressing fusion protein gene of the spider insecticidal peptide and Bt-toxin C-peptide.

    PubMed

    Cao, Chuan-Wang; Liu, Gui-Feng; Wang, Zhi-Ying; Yan, Shan-Chun; Ma, Ling; Yang, Chuan-Ping

    2010-01-01

    The response of the Asian gypsy moth Lymantria dispar (L.) (Lepidoptera: Lymantriidae) to a fusion gene consisting of the spider, Atrax robustus Simon (Araneae: Hexanthelidae) ω-ACTX-Ar1 sequence coding for an ω-atracotoxin and a sequence coding for the Bt-toxin C-peptide, expressed in transgenic poplar Populus simonii x P. nigra L. (Malphigiales: Salicaceae) was investigated. Individual performance, feeding selection, midgut proteinase activity and nutrition utilization were monitored. The growth and development of L. dispar were significantly affected by continually feeding on the transgenic poplar, with the larval instars displaying significantly shorter developmental times than those fed on nontransgenic poplar, but pupation was delayed. Mortality was higher in populations fed transgenic poplar leaves, than for larvae fed nontransgenic poplar leaves. The cumulative mortality during all stages of larvae fed transgenic leaves was 92% compared to 16.7% of larvae on nontransgenic leaves. The highest mortality observed was 71.7% in the last larval instar stage. A two-choice test showed that fifth-instar larvae preferred to feed on nontransgenic leaves at a ratio of 1:1.4. Feeding on transgenic leaves had highly significant negative effects on relative growth of larvae, and the efficiency of conversion of ingested and digested food. Activity of major midgut proteinases was measured using substrates TAME and BTEE showed significant increases in tryptase and chymotrypsinlike activity (9.2- and 9.0-fold, respectively) in fifth-instar larvae fed on transgenic leaves over control. These results suggest transgenic poplar is resistant to L. dispar, and the mature L. dispar may be weakened by the transgenic plants due to Bt protoxins activated by elevated major midgut proteinase activity. The new transgenic poplar expressing fusion protein genes of Bt and a new spider insecticidal peptide are good candidates for managing gypsy moth.

  14. The Development of Norm-Based Coding and Race-Specific Face Prototypes: An Examination of 5- and 8-Year-Olds' Face Space

    ERIC Educational Resources Information Center

    Short, Lindsey A.; Hatry, Alexandra J.; Mondloch, Catherine J.

    2011-01-01

    The current research investigated the organization of children's face space by examining whether 5- and 8-year-olds show race-contingent aftereffects. Participants read a storybook in which Caucasian and Chinese children's faces were distorted in opposite directions. Before and after adaptation, participants judged the normality/attractiveness of…

  15. Why Won't My Torch Work? Physics for 4 to 8 Year Olds. Australian Early Childhood Resource Booklets No. 1.

    ERIC Educational Resources Information Center

    Fleer, Marilyn

    Young children in Australia enter early childhood education settings eager to make sense of the world that surrounds them. Their interest in every day experiences is evident in the range of questions asked, many of which are scientific in nature. Intended as a resource for adults working with 4-to 8-year-old children, this booklet provides an…

  16. Overexpression of gibberellin 20-oxidase1 from Pinus densiflora results in enhanced wood formation with gelatinous fiber development in a transgenic hybrid poplar.

    PubMed

    Park, Eung-Jun; Kim, Hyun-Tae; Choi, Young-Im; Lee, Chanhui; Nguyen, Van Phap; Jeon, Hyung-Woo; Cho, Jin-Seong; Funada, Ryo; Pharis, Richard P; Kurepin, Leonid V; Ko, Jae-Heung

    2015-11-01

    Gibberellins (GAs) are important regulators of plant shoot biomass growth, and GA 20-oxidase (GA20ox) is one of the major regulatory enzymes in the GA biosynthetic pathway. Previously, we showed that the expression levels of a putative GA20ox1 (i.e., PdGA20ox1) in stem tissue of 3-month-old seedlings of 12 families of Pinus densiflora were positively correlated with stem diameter growth across those same families growing in an even-aged 32-year-old pine forest (Park EJ, Lee WY, Kurepin LV, Zhang R, Janzen L, Pharis RP (2015) Plant hormone-assisted early family selection in Pinus densiflora via a retrospective approach. Tree Physiol 35:86-94). To further investigate the molecular function of this gene in the stem wood growth of forest trees, we produced transgenic poplar lines expressing PdGA20ox1 under the control of the 35S promoter (designated as 35S::PdGA20ox1). By age 3 months, most of the 35S::PdGA20ox1 poplar trees were showing an exceptional enhancement of stem wood growth, i.e., up to fourfold increases in stem dry weight, compared with the nontransformed control poplar plants. Significant increases in endogenous GA1, its immediate precursor (GA20) and its catabolite (GA8) in elongating internode tissue accompanied the increased stem growth in the transgenic lines. Additionally, the development of gelatinous fibers occurred in vertically grown stems of the 35S::PdGA20ox1 poplars. An analysis of the cell wall monosaccharide composition of the 35S::PdGA20ox1 poplars showed significant increases in xylose and glucose contents, indicating a qualitative increase in secondary wall depositions. Microarray analyses led us to find a total of 276 probe sets that were upregulated (using threefold as a threshold) in the stem tissues of 35S::PdGA20ox1 poplars relative to the controls. 'Cell organization or biogenesis'- and 'cell wall'-related genes were overrepresented, including many of genes that are involved in cell wall modification. Several transcriptional

  17. Improved saccharification and ethanol yield from field-grown transgenic poplar deficient in cinnamoyl-CoA reductase.

    PubMed

    Van Acker, Rebecca; Leplé, Jean-Charles; Aerts, Dirk; Storme, Véronique; Goeminne, Geert; Ivens, Bart; Légée, Frédéric; Lapierre, Catherine; Piens, Kathleen; Van Montagu, Marc C E; Santoro, Nicholas; Foster, Clifton E; Ralph, John; Soetaert, Wim; Pilate, Gilles; Boerjan, Wout

    2014-01-14

    Lignin is one of the main factors determining recalcitrance to enzymatic processing of lignocellulosic biomass. Poplars (Populus tremula x Populus alba) down-regulated for cinnamoyl-CoA reductase (CCR), the enzyme catalyzing the first step in the monolignol-specific branch of the lignin biosynthetic pathway, were grown in field trials in Belgium and France under short-rotation coppice culture. Wood samples were classified according to the intensity of the red xylem coloration typically associated with CCR down-regulation. Saccharification assays under different pretreatment conditions (none, two alkaline, and one acid pretreatment) and simultaneous saccharification and fermentation assays showed that wood from the most affected transgenic trees had up to 161% increased ethanol yield. Fermentations of combined material from the complete set of 20-mo-old CCR-down-regulated trees, including bark and less efficiently down-regulated trees, still yielded ∼ 20% more ethanol on a weight basis. However, strong down-regulation of CCR also affected biomass yield. We conclude that CCR down-regulation may become a successful strategy to improve biomass processing if the variability in down-regulation and the yield penalty can be overcome.

  18. Improved saccharification and ethanol yield from field-grown transgenic poplar deficient in cinnamoyl-CoA reductase

    PubMed Central

    Van Acker, Rebecca; Leplé, Jean-Charles; Aerts, Dirk; Storme, Véronique; Goeminne, Geert; Ivens, Bart; Légée, Frédéric; Lapierre, Catherine; Piens, Kathleen; Van Montagu, Marc C. E.; Santoro, Nicholas; Foster, Clifton E.; Ralph, John; Soetaert, Wim; Pilate, Gilles; Boerjan, Wout

    2014-01-01

    Lignin is one of the main factors determining recalcitrance to enzymatic processing of lignocellulosic biomass. Poplars (Populus tremula x Populus alba) down-regulated for cinnamoyl-CoA reductase (CCR), the enzyme catalyzing the first step in the monolignol-specific branch of the lignin biosynthetic pathway, were grown in field trials in Belgium and France under short-rotation coppice culture. Wood samples were classified according to the intensity of the red xylem coloration typically associated with CCR down-regulation. Saccharification assays under different pretreatment conditions (none, two alkaline, and one acid pretreatment) and simultaneous saccharification and fermentation assays showed that wood from the most affected transgenic trees had up to 161% increased ethanol yield. Fermentations of combined material from the complete set of 20-mo-old CCR–down-regulated trees, including bark and less efficiently down-regulated trees, still yielded ∼20% more ethanol on a weight basis. However, strong down-regulation of CCR also affected biomass yield. We conclude that CCR down-regulation may become a successful strategy to improve biomass processing if the variability in down-regulation and the yield penalty can be overcome. PMID:24379366

  19. [The functional state of the cardiovascular system and the level of physical performance in 7-8-year-old children under conditions of aerotechnogenic pollution].

    PubMed

    Tuliakova, O V

    2012-01-01

    The aim of the study was to investigate the functional state of the cardiovascular system and the level of physical performance in 7-8-year-old children living in the urban area where air pollution caused by heavy vehicle traffic is high. The cardiovascular system and physical performance were evaluated using the conventional methods in 7-8-year-old 1097 children: a control group included 652 children (363 boys and 289 girls) and a comparison group consisted of 445 persons (239 boys and 206 girls). Under aerotechnogenic pollution, diastolic and mean blood pressures were found to be higher in both groups; the maximum oxygen consumption was lower in the boys and the girls had a decreased heart rate following 4-minute exercise.

  20. Birt-Hogg-Dubé Syndrome Presenting as a Nevus Comedonicus-Like Lesion in an 8-Year-Old Boy.

    PubMed

    Sprague, Jessica; Landau, Joseph W

    2016-09-01

    Birt-Hogg-Dubé syndrome is an uncommon genodermatosis characterized by hair follicle hamartomas and an increased risk of pneumothorax and renal cell carcinoma. Recognition of cutaneous manifestations is essential because it allows for early screening and management of systemic complications. We present the case of an 8-year-old boy with a recently described cystic and comedonal variant of the classic fibrofolliculoma, which had been present since birth.

  1. Mental Rotation with Tangible Three-Dimensional Objects: A New Measure Sensitive to Developmental Differences in 4- to 8-year-old Children

    ERIC Educational Resources Information Center

    Hawes, Zachary; LeFevre, Jo-Anne; Xu, Chang; Bruce, Catherine D.

    2015-01-01

    There is an emerging consensus that spatial thinking is fundamental to later success in math and science. The goals of this study were to design and evaluate a novel test of three-dimensional (3D) mental rotation for 4- to 8-year-old children (N?=?165) that uses tangible 3D objects. Results revealed that the measure was both valid and reliable and…

  2. Transgenic manipulation of a single polyamine in poplar cells affects the accumulation of all amino acids.

    PubMed

    Mohapatra, Sridev; Minocha, Rakesh; Long, Stephanie; Minocha, Subhash C

    2010-04-01

    The polyamine metabolic pathway is intricately connected to metabolism of several amino acids. While ornithine and arginine are direct precursors of putrescine, they themselves are synthesized from glutamate in multiple steps involving several enzymes. Additionally, glutamate is an amino group donor for several other amino acids and acts as a substrate for biosynthesis of proline and gamma-aminobutyric acid, metabolites that play important roles in plant development and stress response. Suspension cultures of poplar (Populus nigra x maximowiczii), transformed with a constitutively expressing mouse ornithine decarboxylase gene, were used to study the effect of up-regulation of putrescine biosynthesis (and concomitantly its enhanced catabolism) on cellular contents of various protein and non-protein amino acids. It was observed that up-regulation of putrescine metabolism affected the steady state concentrations of most amino acids in the cells. While there was a decrease in the cellular contents of glutamine, glutamate, ornithine, arginine, histidine, serine, glycine, cysteine, phenylalanine, tryptophan, aspartate, lysine, leucine and methionine, an increase was seen in the contents of alanine, threonine, valine, isoleucine and gamma-aminobutyric acid. An overall increase in percent cellular nitrogen and carbon content was also observed in high putrescine metabolizing cells compared to control cells. It is concluded that genetic manipulation of putrescine biosynthesis affecting ornithine consumption caused a major change in the entire ornithine biosynthetic pathway and had pleiotropic effects on other amino acids and total cellular carbon and nitrogen, as well. We suggest that ornithine plays a key role in regulating this pathway.

  3. Kleine-Levin Syndrome in an 8-Year-Old Girl with Autistic Disorder: Does Autism Account a Primary or Secondary Cause?

    PubMed

    Hakim Shoushtari, Mitra; Ghalebandi, Mirfarhad; Tavasoli, Azita; Pourshams, Maryam

    2015-01-01

    Objective Kleine-Levin syndrome (KLS) is a rare disorder with an unknown etiology. Autism spectrum disorder is characterized by various degrees of impairment in social communication, repetitive behavior and restricted interests. Only four patients of KLS with autistic spectrum disorder (ASD) have been reported so far. This report presents an 8-year-old girl with history of autistic disorder and epilepsy that superimposed KLS. Because of the rarity of KLS and related studies did not address whether autism accounts for a primary or secondary cause, the area required attention further studies.

  4. Children's Teleological Intuitions: What Kind of Explanations Do 7-8 Year Olds Give for the Features of Organisms, Artifacts and Natural Objects?

    NASA Astrophysics Data System (ADS)

    Kampourakis, Kostas; Pavlidi, Vasiliki; Papadopoulou, Maria; Palaiokrassa, Eirini

    2012-08-01

    Research has shown that children usually provide teleological explanations for the features of organisms from a very early age (3-4 years old). However, it is not clear if teleology is applied selectively for organisms, or if it is generally applied to other objects as well (artifacts and non-living natural objects). The present study examined whether 7-8 year old students provided teleological explanations for particular organisms, artifacts and natural objects. We investigated whether children's familiarity with these objects influenced the types of explanations they gave. Finally, we also investigated correlations between 'teleology' and 'usefulness' in children's explanations. The results indicate that 7-8 year olds are able to distinguish between living and non-living entities, as well as that they provide teleological explanations mostly for organisms and artifacts. This may have important implications for biological education, since teleological explanations in classrooms are likely to pose important conceptual obstacles to the development of a scientific understanding of evolution.

  5. The ability of 6- to 8-year-old children to use motor imagery in a goal-directed pointing task.

    PubMed

    Spruijt, Steffie; van der Kamp, John; Steenbergen, Bert

    2015-11-01

    It has been suggested that motor imagery ability develops gradually between 5 and 12 years of age, but ambiguity remains over the precise developmental course before 9 years. Hence, we determined the age-related differences in the use of motor imagery by children on the mental chronometry paradigm. In addition, we examined whether the use of motor imagery is related to cognitive and hand abilities. To this end, we compared duration of actual pointing and imagined pointing on a radial Fitts' task in 82 children (three age groups; 6-, 7-, and 8-year-olds). In line with previous studies, we found an age-related increase in temporal congruence between actual and imagined pointing and compliance with Fitts' law. Importantly, however, we showed that only a limited number of 7- and 8-year-olds were actually using motor imagery to perform the imagined pointing task, whereas the 6-year-olds did not employ motor imagery to perform the task. The current results extend previous research by establishing that the age of onset to use motor imagery in the mental chronometry paradigm is not prior to 7 years. PMID:26163179

  6. The development of norm-based coding and race-specific face prototypes: an examination of 5- and 8-year-olds' face space.

    PubMed

    Short, Lindsey A; Hatry, Alexandra J; Mondloch, Catherine J

    2011-02-01

    The current research investigated the organization of children's face space by examining whether 5- and 8-year-olds show race-contingent aftereffects. Participants read a storybook in which Caucasian and Chinese children's faces were distorted in opposite directions. Before and after adaptation, participants judged the normality/attractiveness of expanded, compressed, and undistorted Caucasian and Chinese faces. The method was validated with adults and then refined to test 8- and 5-year-olds. The 5-year-olds were also tested in a simple aftereffects paradigm. The current research provides the first evidence for simple attractiveness aftereffects in 5-year-olds and for race-contingent aftereffects in both 5- and 8-year-olds. Evidence that adults and 5-year-olds may possess only a weak prototype for Chinese children's faces suggests that Caucasian adults' prototype for Chinese adult faces does not generalize to child faces and that children's face space undergoes a period of increasing differentiation between 5 and 8 years of age.

  7. Sulphur flux through the sulphate assimilation pathway is differently controlled by adenosine 5'-phosphosulphate reductase under stress and in transgenic poplar plants overexpressing gamma-ECS, SO, or APR.

    PubMed

    Scheerer, Ursula; Haensch, Robert; Mendel, Ralf R; Kopriva, Stanislav; Rennenberg, Heinz; Herschbach, Cornelia

    2010-01-01

    Sulphate assimilation provides reduced sulphur for the synthesis of cysteine, methionine, and numerous other essential metabolites and secondary compounds. The key step in the pathway is the reduction of activated sulphate, adenosine 5'-phosphosulphate (APS), to sulphite catalysed by APS reductase (APR). In the present study, [(35)S]sulphur flux from external sulphate into glutathione (GSH) and proteins was analysed to check whether APR controls the flux through the sulphate assimilation pathway in poplar roots under some stress conditions and in transgenic poplars. (i) O-Acetylserine (OAS) induced APR activity and the sulphur flux into GSH. (ii) The herbicide Acetochlor induced APR activity and results in a decline of GSH. Thereby the sulphur flux into GSH or protein remained unaffected. (iii) Cd treatment increased APR activity without any changes in sulphur flux but lowered sulphate uptake. Several transgenic poplar plants that were manipulated in sulphur metabolism were also analysed. (i) Transgenic poplar plants that overexpressed the gamma-glutamylcysteine synthetase (gamma-ECS) gene, the enzyme catalysing the key step in GSH formation, showed an increase in sulphur flux into GSH and sulphate uptake when gamma-ECS was targeted to the cytosol, while no changes in sulphur flux were observed when gamma-ECS was targeted to plastids. (ii) No effect on sulphur flux was observed when the sulphite oxidase (SO) gene from Arabidopsis thaliana, which catalyses the back reaction of APR, that is the reaction from sulphite to sulphate, was overexpressed. (iii) When Lemna minor APR was overexpressed in poplar, APR activity increased as expected, but no changes in sulphur flux were observed. For all of these experiments the flux control coefficient for APR was calculated. APR as a controlling step in sulphate assimilation seems obvious under OAS treatment, in gamma-ECS and SO overexpressing poplars. A possible loss of control under certain conditions, that is Cd treatment

  8. Fiber tracking of the frontal aslant tract and subcomponents of the arcuate fasciculus in 5-8-year-olds: Relation to speech and language function.

    PubMed

    Broce, Iris; Bernal, Byron; Altman, Nolan; Tremblay, Pascale; Dick, Anthony Steven

    2015-10-01

    Long association cortical fiber pathways support developing networks for speech and language, but we do not have a clear understanding of how they develop in early childhood. Using diffusion-weighted imaging (DWI) we tracked the frontal aslant tract (FAT), arcuate fasciculus (AF), and AF segments (anterior, long, posterior) in 19 typical 5-8-year-olds, an age range in which significant improvement in speech and language function occurs. While the microstructural properties of the FAT and the right AF did not show age-related differences over the age range we investigated, the left AF evidenced increasing fractional anisotropy with age. Microstructural properties of the AF in both hemispheres, however, predicted receptive and expressive language. Length of the left FAT also predicted receptive language, which provides initial suggestion that this pathway is important for language development. These findings have implications for models of language development and for models of the neurobiology of language more broadly.

  9. A Right Middle Cerebral Artery Infarct After Frontal Eosinophilic Granuloma Resection in an 8-Year-Old Boy with Factor V Leiden.

    PubMed

    Cakir, Ertugrul; Arslan, Erhan; Yazar, Ugur; Reis, Gokce Pinar

    2015-01-01

    Stroke in children is relatively uncommon. We describe an 8-year-old boy diagnosed with primary eosinophilic granuloma (EG) of the frontal bone. After excision of the EG, the postoperative course was eventful. The patient had an acute right middle cerebral artery (MCA) infarct and had been comatose with a diminished Glasgow Coma Scale (GCS) score of 5. Urgent decompressive hemicraniectomy with duraplasty was performed. The postoperative course after the second operation was uneventful. Hematological tests revealed a diagnosis of factor V Leiden. The patient was discharged with left hemiparesis and GCS of 15. To the best of our knowledge, no such clinical picture of MCA infarction after EG excision has been described before. Neurosurgeons should be aware of inherited thrombophilias, such as factor V Leiden, if the postoperative clinical course worsens because of cerebral artery thrombosis. Also, decompressive hemicraniectomy could be life saving and should be performed urgently without any hesitation. PMID:26442559

  10. Transgenic upregulation of the condensed tannin pathway in poplar leads to a dramatic shift in leaf palatability for two tree-feeding Lepidoptera.

    PubMed

    Boeckler, G Andreas; Towns, Megan; Unsicker, Sybille B; Mellway, Robin D; Yip, Lynn; Hilke, Ines; Gershenzon, Jonathan; Constabel, C Peter

    2014-02-01

    Transgenic hybrid aspen (Populus tremula x tremuloides) overexpressing the MYB134 tannin regulatory gene show dramatically enhanced condensed tannin (proanthocyanidin) levels, as well as shifts in other phenolic metabolites. A series of insect bioassays with forest tent caterpillars (Malacosoma disstria) and gypsy moth (Lymantria dispar) caterpillars was carried out to determine how this metabolic shift affects food preference and performance of generalist tree-feeding lepidopterans. Both species showed a distinct preference for the high-tannin MYB134 overexpressor plants, and L. dispar performance was enhanced relative to controls. L. dispar reached greater pupal weight and showed reduced time to pupation when reared on the MYB134 overexpressing poplar. These results were unexpected since enhanced condensed tannin levels were predicted to act as feeding deterrents. However, the data may be explained by the observed decrease in the salicinoids (phenolic glycosides) salicortin and tremulacin that accompanied the upregulation of the condensed tannins in the transgenics. We conclude that for these two lepidopteran species, condensed tannin levels are unlikely to be a major determinant of caterpillar food preference or performance. However, our experiments show that overexpression of a single regulatory gene in transgenic aspen can have a significant impact on herbivorous insects.

  11. Transgenic upregulation of the condensed tannin pathway in poplar leads to a dramatic shift in leaf palatability for two tree-feeding Lepidoptera.

    PubMed

    Boeckler, G Andreas; Towns, Megan; Unsicker, Sybille B; Mellway, Robin D; Yip, Lynn; Hilke, Ines; Gershenzon, Jonathan; Constabel, C Peter

    2014-02-01

    Transgenic hybrid aspen (Populus tremula x tremuloides) overexpressing the MYB134 tannin regulatory gene show dramatically enhanced condensed tannin (proanthocyanidin) levels, as well as shifts in other phenolic metabolites. A series of insect bioassays with forest tent caterpillars (Malacosoma disstria) and gypsy moth (Lymantria dispar) caterpillars was carried out to determine how this metabolic shift affects food preference and performance of generalist tree-feeding lepidopterans. Both species showed a distinct preference for the high-tannin MYB134 overexpressor plants, and L. dispar performance was enhanced relative to controls. L. dispar reached greater pupal weight and showed reduced time to pupation when reared on the MYB134 overexpressing poplar. These results were unexpected since enhanced condensed tannin levels were predicted to act as feeding deterrents. However, the data may be explained by the observed decrease in the salicinoids (phenolic glycosides) salicortin and tremulacin that accompanied the upregulation of the condensed tannins in the transgenics. We conclude that for these two lepidopteran species, condensed tannin levels are unlikely to be a major determinant of caterpillar food preference or performance. However, our experiments show that overexpression of a single regulatory gene in transgenic aspen can have a significant impact on herbivorous insects. PMID:24496605

  12. Green Revolution Trees: Semidwarfism Transgenes Modify Gibberellins, Promote Root Growth, Enhance Morphological Diversity, and Reduce Competitiveness in Hybrid Poplar1[C][W][OA

    PubMed Central

    Elias, Ani A.; Busov, Victor B.; Kosola, Kevin R.; Ma, Cathleen; Etherington, Elizabeth; Shevchenko, Olga; Gandhi, Harish; Pearce, David W.; Rood, Stewart B.; Strauss, Steven H.

    2012-01-01

    Semidwarfism has been used extensively in row crops and horticulture to promote yield, reduce lodging, and improve harvest index, and it might have similar benefits for trees for short-rotation forestry or energy plantations, reclamation, phytoremediation, or other applications. We studied the effects of the dominant semidwarfism transgenes GA Insensitive (GAI) and Repressor of GAI-Like, which affect gibberellin (GA) action, and the GA catabolic gene, GA 2-oxidase, in nursery beds and in 2-year-old high-density stands of hybrid poplar (Populus tremula × Populus alba). Twenty-nine traits were analyzed, including measures of growth, morphology, and physiology. Endogenous GA levels were modified in most transgenic events; GA20 and GA8, in particular, had strong inverse associations with tree height. Nearly all measured traits varied significantly among genotypes, and several traits interacted with planting density, including aboveground biomass, root-shoot ratio, root fraction, branch angle, and crown depth. Semidwarfism promoted biomass allocation to roots over shoots and substantially increased rooting efficiency with most genes tested. The increased root proportion and increased leaf chlorophyll levels were associated with changes in leaf carbon isotope discrimination, indicating altered water use efficiency. Semidwarf trees had dramatically reduced growth when in direct competition with wild-type trees, supporting the hypothesis that semidwarfism genes could be effective tools to mitigate the spread of exotic, hybrid, and transgenic plants in wild and feral populations. PMID:22904164

  13. Higher Weight Status of Only and Last-Born Children: Maternal Feeding and Child Eating Behaviors as Underlying Processes among 4-8 Year Olds

    PubMed Central

    Mosli, Rana H.; Lumeng, Julie C.; Kaciroti, Niko; Peterson, Karen E.; Rosenblum, Katherine; Baylin, Ana; Miller, Alison L.

    2015-01-01

    Birth order has been associated with childhood obesity. The objective of this cross-sectional study was to examine maternal feeding and child eating behaviors as underlying processes for increased weight status of only children and youngest siblings. Participants included 274 low-income 4-8 year old children and their mothers. The dyads completed a videotaped laboratory mealtime observation. Mothers completed the Caregiver's Feeding Styles Questionnaire and the Children's Eating Behavior Questionnaire. Child weight and height were measured using standardized procedures. Path analysis was used to examine associations of birth order, maternal feeding behaviors, child eating behavior, and child overweight/obese status. The association between only child status and greater likelihood of overweight/obesity was fully mediated by higher maternal Verbal Discouragement to eat and lower maternal Praise (all p values < 0.05). The association between youngest sibling status and greater likelihood of overweight/obesity was partially mediated by lower maternal Praise and lower child Food Fussiness (all p values < 0.05). Results provide support for our hypothesis that maternal control and support and child food acceptance are underlying pathways for the association between birth order and weight status. Future findings can help inform family-based programs by guiding family counseling and tailoring of recommendations for family mealtime interactions. PMID:26009204

  14. Higher weight status of only and last-born children. Maternal feeding and child eating behaviors as underlying processes among 4-8 year olds.

    PubMed

    Mosli, Rana H; Lumeng, Julie C; Kaciroti, Niko; Peterson, Karen E; Rosenblum, Katherine; Baylin, Ana; Miller, Alison L

    2015-09-01

    Birth order has been associated with childhood obesity. The objective of this cross-sectional study was to examine maternal feeding and child eating behaviors as underlying processes for increased weight status of only children and youngest siblings. Participants included 274 low-income 4-8 year old children and their mothers. The dyads completed a videotaped laboratory mealtime observation. Mothers completed the Caregiver's Feeding Styles Questionnaire and the Children's Eating Behavior Questionnaire. Child weight and height were measured using standardized procedures. Path analysis was used to examine associations of birth order, maternal feeding behavior, child eating behavior, and child overweight/obese status. The association between only child status and greater likelihood of overweight/obesity was fully mediated by higher maternal Verbal Discouragement to eat and lower maternal Praise (all p values < 0.05). The association between youngest sibling status and greater likelihood of overweight/obesity was partially mediated by lower maternal Praise and lower child Food Fussiness (all p values < 0.05). Results provide support for our hypothesis that maternal control and support and child food acceptance are underlying pathways for the association between birth order and weight status. Future findings can help inform family-based programs by guiding family counseling and tailoring of recommendations for family mealtime interactions.

  15. The influence of maternal self-objectification, materialism and parenting style on potentially sexualized 'grown up' behaviours and appearance concerns in 5-8year old girls.

    PubMed

    Slater, Amy; Tiggemann, Marika

    2016-08-01

    There is widespread concern about young girls displaying 'grown up' or sexualized behaviours, as well as experiencing body image and appearance concerns that were previously thought to only impact much older girls. The present study examined the influence of three maternal attributes, self-objectification, materialism and parenting style, on sexualized behaviours and appearance concerns in young girls. A sample of 252 Australian mothers of 5-8year old girls reported on the behaviours and appearance concerns observed in their daughters and also completed measures of their own self-objectification, materialism and parenting style. It was found that a significant proportion of young girls were engaging with 'teen' culture, using beauty products and expressing some degree of appearance concern. Maternal self-objectification was related to daughters' engagement in teen culture, use of beauty products and appearance concern. Maternal materialism was related to girls' engagement in teen culture and appearance concern, while an authoritative parenting style was negatively related to girls' use of beauty products. The findings suggest that maternal self-objectification and materialism play a role in the body image and appearance concerns of young girls, and in so doing, identify these maternal attributes as novel potential targets for intervention. PMID:27203569

  16. Developing the IDEFICS community-based intervention program to enhance eating behaviors in 2- to 8-year-old children: findings from focus groups with children and parents.

    PubMed

    Haerens, L; De Bourdeaudhuij, I; Barba, G; Eiben, G; Fernandez, J; Hebestreit, A; Kovács, E; Lasn, H; Regber, S; Shiakou, M; De Henauw, S

    2009-06-01

    One purpose of 'identification and prevention of dietary- and lifestyle-induced health effects in children and infants' (IDEFICS) is to implement a standardized community-based multi-component healthy eating intervention for younger children in eight different countries. The present study describes important influencing factors for dietary behaviors among children aged 2-8 years old in order to determine the best approaches for developing the dietary components of the standardized intervention. Twenty focus groups with children (74 boys, 81 girls) and 36 focus groups with 189 parents (28 men, 161 women) were conducted. Only in two countries, children mentioned receiving nutrition education at school. Rules at home and at school ranged from not allowing the consumption of unhealthy products to allowing everything. The same diversity was found for availability of (un)healthy products at home and school. Parents mentioned personal (lack of time, financial constraints, preferences), socio-environmental (family, peer influences), institutional (school policies) and physical-environmental (availability of unhealthy products, price, season) barriers for healthy eating. This focus group research provided valuable information to guide the first phase in the IDEFICS intervention development. There was a large variability in findings within countries. Interventions should be tailored at the personal and environmental level to increase the likelihood of behavioral change. PMID:18603656

  17. The influence of maternal self-objectification, materialism and parenting style on potentially sexualized 'grown up' behaviours and appearance concerns in 5-8year old girls.

    PubMed

    Slater, Amy; Tiggemann, Marika

    2016-08-01

    There is widespread concern about young girls displaying 'grown up' or sexualized behaviours, as well as experiencing body image and appearance concerns that were previously thought to only impact much older girls. The present study examined the influence of three maternal attributes, self-objectification, materialism and parenting style, on sexualized behaviours and appearance concerns in young girls. A sample of 252 Australian mothers of 5-8year old girls reported on the behaviours and appearance concerns observed in their daughters and also completed measures of their own self-objectification, materialism and parenting style. It was found that a significant proportion of young girls were engaging with 'teen' culture, using beauty products and expressing some degree of appearance concern. Maternal self-objectification was related to daughters' engagement in teen culture, use of beauty products and appearance concern. Maternal materialism was related to girls' engagement in teen culture and appearance concern, while an authoritative parenting style was negatively related to girls' use of beauty products. The findings suggest that maternal self-objectification and materialism play a role in the body image and appearance concerns of young girls, and in so doing, identify these maternal attributes as novel potential targets for intervention.

  18. [Study of factors influencing hepatitis B immunization coverage in 1 to 8-years-old children in the Ouidah health district in Benin in 2007].

    PubMed

    Bossali, F; Paraiso, M; Bokossa, A; Fourn, L

    2010-04-01

    Hepatitis B is a major public health problem in Africa. The estimated prevalence in Benin is between 5.2% and 8.3%. Since 1992, the WHO has recommended immunization of all children between 0 and 12-months-old all around the world. Benin has been vaccinating children from 0 to 11 months since 1999. The purpose of this study was to identify factors influencing hepatitis B immunization coverage in children from 1 to 8-years-old in the Ouidah health district. This descriptive and analytical cross sectional study was carried out from October 25 to 31, 2007. The primary study targets were children from 1 to 8 years. Secondary targets were mothers and healthcare workers. A three-degree cluster sampling technique was used. Hepatitis immunization coverage was 72.2% (95%CI, 65.4 - 78.3). The negative factor influencing coverage in children was age over 5 years reflecting the absence of catch-up sessions for untargeted children overlooked for hepatitis B immunization. The negative factor in mothers was age over 30 years pending multivariate analysis that was not performed in this study. Regarding healthcare workers, understaffing was noted at this level of the health system. Hepatitis B immunization coverage in untargeted children was lower than in children between 0 and 11 months. In 2007, hepatitis B immunization coverage in the Ouidah health district was lower in untargeted children than children of 0 to 11 months. This study showed that immunization coverage decreased with age, thus underlining the need for catch-up sessions to ensure hepatitis B immunization in high prevalence areas.

  19. Tyloses and Phenolic Deposits in Xylem Vessels Impede Water Transport in Low-Lignin Transgenic Poplars: A Study by Cryo-Fluorescence Microscopy1[W][OA

    PubMed Central

    Kitin, Peter; Voelker, Steven L.; Meinzer, Frederick C.; Beeckman, Hans; Strauss, Steven H.; Lachenbruch, Barbara

    2010-01-01

    Of 14 transgenic poplar genotypes (Populus tremula × Populus alba) with antisense 4-coumarate:coenzyme A ligase that were grown in the field for 2 years, five that had substantial lignin reductions also had greatly reduced xylem-specific conductivity compared with that of control trees and those transgenic events with small reductions in lignin. For the two events with the lowest xylem lignin contents (greater than 40% reduction), we used light microscopy methods and acid fuchsin dye ascent studies to clarify what caused their reduced transport efficiency. A novel protocol involving dye stabilization and cryo-fluorescence microscopy enabled us to visualize the dye at the cellular level and to identify water-conducting pathways in the xylem. Cryo-fixed branch segments were planed in the frozen state on a sliding cryo-microtome and observed with an epifluorescence microscope equipped with a cryo-stage. We could then distinguish clearly between phenolic-occluded vessels, conductive (stain-filled) vessels, and nonconductive (water- or gas-filled) vessels. Low-lignin trees contained areas of nonconductive, brown xylem with patches of collapsed cells and patches of noncollapsed cells filled with phenolics. In contrast, phenolics and nonconductive vessels were rarely observed in normal colored wood of the low-lignin events. The results of cryo-fluorescence light microscopy were supported by observations with a confocal microscope after freeze drying of cryo-planed samples. Moreover, after extraction of the phenolics, confocal microscopy revealed that many of the vessels in the nonconductive xylem were blocked with tyloses. We conclude that reduced transport efficiency of the transgenic low-lignin xylem was largely caused by blockages from tyloses and phenolic deposits within vessels rather than by xylem collapse. PMID:20639405

  20. Changes in dental caries and oral hygiene among 7-8 year-old schoolchildren in different regions of Lithuania 1983-2009.

    PubMed

    Matulaitiene, Zivilė Kristina; Zemaitiene, Migle; Zemgulyte, Sandra; Milciuviene, Simona

    2012-01-01

    The objectives of this study were to evaluate and compare the changes of the dental caries prevalence and severity of 7 to 8 year old schoolchildren in six Lithuanian regions over the past 26 years (1983-2009) and to propose recommendations based on the results of the study. The study is based on the analysis of data, containing 576 cases of children examined in 1983 and comparison with data containing 531 cases added in 2009. The studies were conducted in the same six regions of Lithuania among the children from 7 to 8 years of age. For the study of children the WHO oral assessment methodology was used (WHO Basic methods 1997). Severity of dental caries was described by df-t and DMF-T index. The average of individual df-t and DMF-T indices was calculated for all subjects and sorted by gender. Oral hygiene status was evaluated by applying the simplified Green-Vermilion index-OHI-S (1964) The prevalence of primary dental caries among the children 7 to 8 years of age was 92.4% in 1983 and 88.7% (p=0.43) in 2009. The prevalence of permanent dental caries decreased from 49.6% in 1983 to 29.7% (p<0.001) in 2009. Mean df-t score decreased from 4.9±3.4 in 1983 to 4.1±2.7 in 2009 and DMF-T index decreased from 1.1±1.7 in 1983 to 0.5±1.0 in 2009 (p<0.001). The OHI-S index was not significantly different during 1983-2009. In the period of last 26 years a tendency towards the decrease in the prevalence and severity of dental caries was observed. That could be related to the frequent using of the toothpastes with fluoride, as well as implementation of the caries prevention program with sealants among the children of that age. The poor oral hygiene and comparatively high caries prevalence in schoolchildren show that it is still necessary to improve preventive measures in Lithuania.

  1. The effects of high-tannin leaf litter from transgenic poplars on microbial communities in microcosm soils.

    PubMed

    Winder, Richard S; Lamarche, Josyanne; Constabel, C Peter; Hamelin, Richard C

    2013-01-01

    The impacts of leaf litter from genetically modified hybrid poplar accumulating high levels of condensed tannins (proanthocyanidins) were examined in soil microcosms consisting of moss growing on sieved soil. Moss preferentially proliferated in microcosms with lower tannin content; DGGE (denaturing gradient gel electrophoresis) detected increased fungal diversity in microcosms with low-tannin litter. The proportion of cloned rDNA sequences from Actinobacteria decreased with litter addition while Bacteroidetes, Chloroflexi, Cyanobacteria, and α-Proteobacteria significantly increased. β-Proteobacteria were proportionally more numerous at high-tannin levels. Tannins had no significant impact on overall diversity of bacterial communities analyzed with various estimators. There was an increased proportion of N-fixing bacteria corresponding to the addition of litter with low-tannin levels. The addition of litter increased the proportion of Ascomycota/Basidiomycota. Dothideomycetes, Pucciniomycetes, and Tremellomycetes also increased and Agaricomycetes decreased. Agaricomycetes and Sordariomycetes were significantly more abundant in controls, whereas Pucciniomycetes increased in soil with litter from transformed trees (P = 0.051). Richness estimators and diversity indices revealed no significant difference in the composition of fungal communities; PCoA (principal coordinate analyses) partitioned the fungal communities into three groups: (i) those with higher amounts of added tannin from both transformed and untransformed treatments, (ii) those corresponding to soils without litter, and (iii) those corresponding to microcosms with litter added from trees transformed only with a β-glucuronidase control vector. While the litter from transformed poplars had significant effects on soil microbe communities, the observed impacts reflected known impacts on soil processes associated with tannins, and were similar to changes that would be expected from natural variation in

  2. The effects of high-tannin leaf litter from transgenic poplars on microbial communities in microcosm soils

    PubMed Central

    Winder, Richard S.; Lamarche, Josyanne; Constabel, C. Peter; Hamelin, Richard C.

    2013-01-01

    The impacts of leaf litter from genetically modified hybrid poplar accumulating high levels of condensed tannins (proanthocyanidins) were examined in soil microcosms consisting of moss growing on sieved soil. Moss preferentially proliferated in microcosms with lower tannin content; DGGE (denaturing gradient gel electrophoresis) detected increased fungal diversity in microcosms with low-tannin litter. The proportion of cloned rDNA sequences from Actinobacteria decreased with litter addition while Bacteroidetes, Chloroflexi, Cyanobacteria, and α-Proteobacteria significantly increased. β-Proteobacteria were proportionally more numerous at high-tannin levels. Tannins had no significant impact on overall diversity of bacterial communities analyzed with various estimators. There was an increased proportion of N-fixing bacteria corresponding to the addition of litter with low-tannin levels. The addition of litter increased the proportion of Ascomycota/Basidiomycota. Dothideomycetes, Pucciniomycetes, and Tremellomycetes also increased and Agaricomycetes decreased. Agaricomycetes and Sordariomycetes were significantly more abundant in controls, whereas Pucciniomycetes increased in soil with litter from transformed trees (P = 0.051). Richness estimators and diversity indices revealed no significant difference in the composition of fungal communities; PCoA (principal coordinate analyses) partitioned the fungal communities into three groups: (i) those with higher amounts of added tannin from both transformed and untransformed treatments, (ii) those corresponding to soils without litter, and (iii) those corresponding to microcosms with litter added from trees transformed only with a β-glucuronidase control vector. While the litter from transformed poplars had significant effects on soil microbe communities, the observed impacts reflected known impacts on soil processes associated with tannins, and were similar to changes that would be expected from natural variation in

  3. Comparative genomic analysis of transgenic poplar dwarf mutant reveals numerous differentially expressed genes involved in energy flow.

    PubMed

    Chen, Su; Bai, Shuang; Liu, Guifeng; Li, Huiyu; Jiang, Jing

    2014-01-01

    In our previous research, the Tamarix androssowii LEA gene (Tamarix androssowii late embryogenesis abundant protein Mrna, GenBank ID: DQ663481) was transferred into Populus simonii × Populus nigra. Among the eleven transgenic lines, one exhibited a dwarf phenotype compared to the wild type and other transgenic lines, named dwf1. To uncover the mechanisms underlying this phenotype, digital gene expression libraries were produced from dwf1, wild-type, and other normal transgenic lines, XL-5 and XL-6. Gene expression profile analysis indicated that dwf1 had a unique gene expression pattern in comparison to the other two transgenic lines. Finally, a total of 1246 dwf1-unique differentially expressed genes were identified. These genes were further subjected to gene ontology and pathway analysis. Results indicated that photosynthesis and carbohydrate metabolism related genes were significantly affected. In addition, many transcription factors genes were also differentially expressed in dwf1. These various differentially expressed genes may be critical for dwarf mutant formation; thus, the findings presented here might provide insight for our understanding of the mechanisms of tree growth and development. PMID:25192286

  4. Overexpression of the PtSOS2 gene improves tolerance to salt stress in transgenic poplar plants.

    PubMed

    Yang, Yang; Tang, Ren-Jie; Jiang, Chun-Mei; Li, Bei; Kang, Tao; Liu, Hua; Zhao, Nan; Ma, Xu-Jun; Yang, Lei; Chen, Shao-Liang; Zhang, Hong-Xia

    2015-09-01

    In higher plants, the salt overly sensitive (SOS) signalling pathway plays a crucial role in maintaining ion homoeostasis and conferring salt tolerance under salinity condition. Previously, we functionally characterized the conserved SOS pathway in the woody plant Populus trichocarpa. In this study, we demonstrate that overexpression of the constitutively active form of PtSOS2 (PtSOS2TD), one of the key components of this pathway, significantly increased salt tolerance in aspen hybrid clone Shanxin Yang (Populus davidiana × Populus bolleana). Compared to the wild-type control, transgenic plants constitutively expressing PtSOS2TD exhibited more vigorous growth and produced greater biomass in the presence of high concentrations of NaCl. The improved salt tolerance was associated with a decreased Na(+) accumulation in the leaves of transgenic plants. Further analyses revealed that plasma membrane Na(+) /H(+) exchange activity and Na(+) efflux in transgenic plants were significantly higher than those in the wild-type plants. Moreover, transgenic plants showed improved capacity in scavenging reactive oxygen species (ROS) generated by salt stress. Taken together, our results suggest that PtSOS2 could serve as an ideal target gene to genetically engineer salt-tolerant trees.

  5. Why 8-Year-Olds Cannot Tell the Difference between Steve Martin and Paul Newman: Factors Contributing to the Slow Development of Sensitivity to the Spacing of Facial Features

    ERIC Educational Resources Information Center

    Mondloch, Catherine J.; Dobson, Kate S.; Parsons, Julie; Maurer, Daphne

    2004-01-01

    Children are nearly as sensitive as adults to some cues to facial identity (e.g., differences in the shape of internal features and the external contour), but children are much less sensitive to small differences in the spacing of facial features. To identify factors that contribute to this pattern, we compared 8-year-olds' sensitivity to spacing…

  6. Overexpression of Poplar PtrWRKY89 in Transgenic Arabidopsis Leads to a Reduction of Disease Resistance by Regulating Defense-Related Genes in Salicylate- and Jasmonate-Dependent Signaling.

    PubMed

    Jiang, Yuanzhong; Guo, Li; Liu, Rui; Jiao, Bo; Zhao, Xin; Ling, Zhengyi; Luo, Keming

    2016-01-01

    The plant hormones jasmonic acid (JA) and salicylic acid (SA) play key roles in plant defenses against pathogens and several WRKY transcription factors have been shown to have a role in SA/JA crosstalk. In a previous study, overexpression of the poplar WRKY gene PtrWRKY89 enhanced resistance to pathogens in transgenic poplars. In this study, the promoter of PtrWRKY89 (ProPtrWRKY89) was isolated and used to drive GUS reporter gene. High GUS activity was observed in old leaves of transgenic Arabidopsis containing ProPtrWRKY89-GUS construct and GUS expression was extremely induced by SA solution and SA+MeJA mixture but not by MeJA treatment. Subcellular localization and transactivation assays showed that PtrWRKY89 acted as a transcription activator in the nucleus. Constitutive expression of PtrWRKY89 in Arabidopsis resulted in more susceptible to Pseudomonas syringae and Botrytis cinerea compared to wild-type plants. Quantitative real-time PCR (qRT-PCR) analysis confirmed that marker genes of SA and JA pathways were down-regulated in transgenic Arabidopsis after pathogen inoculations. Overall, our results indicated that PtrWRKY89 modulates a cross talk in resistance to P. syringe and B. cinerea by negatively regulating both SA and JA pathways in Arabidopsis. PMID:27019084

  7. Overexpression of Poplar PtrWRKY89 in Transgenic Arabidopsis Leads to a Reduction of Disease Resistance by Regulating Defense-Related Genes in Salicylate- and Jasmonate-Dependent Signaling

    PubMed Central

    Liu, Rui; Jiao, Bo; Zhao, Xin; Ling, Zhengyi; Luo, Keming

    2016-01-01

    The plant hormones jasmonic acid (JA) and salicylic acid (SA) play key roles in plant defenses against pathogens and several WRKY transcription factors have been shown to have a role in SA/JA crosstalk. In a previous study, overexpression of the poplar WRKY gene PtrWRKY89 enhanced resistance to pathogens in transgenic poplars. In this study, the promoter of PtrWRKY89 (ProPtrWRKY89) was isolated and used to drive GUS reporter gene. High GUS activity was observed in old leaves of transgenic Arabidopsis containing ProPtrWRKY89-GUS construct and GUS expression was extremely induced by SA solution and SA+MeJA mixture but not by MeJA treatment. Subcellular localization and transactivation assays showed that PtrWRKY89 acted as a transcription activator in the nucleus. Constitutive expression of PtrWRKY89 in Arabidopsis resulted in more susceptible to Pseudomonas syringae and Botrytis cinerea compared to wild-type plants. Quantitative real-time PCR (qRT-PCR) analysis confirmed that marker genes of SA and JA pathways were down-regulated in transgenic Arabidopsis after pathogen inoculations. Overall, our results indicated that PtrWRKY89 modulates a cross talk in resistance to P. syringe and B. cinerea by negatively regulating both SA and JA pathways in Arabidopsis. PMID:27019084

  8. CPR - child (1 to 8 years old)

    MedlinePlus

    Rescue breathing and chest compressions - child; Resuscitation - cardiopulmonary - child; Cardiopulmonary resuscitation - child ... All parents and those who take care of children should learn infant and child CPR if they ...

  9. Phytoextraction potential of wild type and 35S-gshI transgenic poplar trees (Populus x Canescens) for environmental pollutants herbicide paraquat, salt sodium, zinc sulfate and nitric oxide in vitro.

    PubMed

    Gyulai, G; Bittsánszky, A; Szabó, Z; Waters, L; Gullner, G; Kampfl, G; Heltai, G; Komíves, T

    2014-01-01

    Phytoextraction potentials of two transgenic (TR) poplar (Populus x canescens) clones TRggs11 and TRlgl6 were compared with that of wild-type (WT) following exposure to paraquat, zinc sulfate, common salt and nitric oxide (NO), using a leaf-disc system incubated for 21 days on EDTA-containing nutritive WPM media in vitro. Glutathione (GSH) contents of leaf discs of TRlgl6 and TRggs11 showed increments to 296% and 190%, respectively, compared with WT. NO exposure led to a twofold GSH content in TRlgl6, which was coupled with a significantly increased sulfate uptake when exposed to 10(-3) M ZnSO4. The highest mineral contents of Na, Zn, Mn, Cu, and Mo was observed in the TRggs11 clone. Salt-induced activity of catalase enzyme increased in both TR clones significantly compared with WT under NaCl (0.75% and 1.5%) exposure. The in silico sequence analyses of gsh1 genes revealed that P. x canadensis and Salix sachalinensis show the closest sequence similarity to that of P. x canescens, which predicted an active GSH production with high phytoextraction potentials of these species with indication for their use where P. x canescens can not be grown.

  10. Genome Enabled Discovery of Carbon Sequestration Genes in Poplar

    SciTech Connect

    Filichkin, Sergei; Etherington, Elizabeth; Ma, Caiping; Strauss, Steve

    2007-02-22

    The goals of the S.H. Strauss laboratory portion of 'Genome-enabled discovery of carbon sequestration genes in poplar' are (1) to explore the functions of candidate genes using Populus transformation by inserting genes provided by Oakridge National Laboratory (ORNL) and the University of Florida (UF) into poplar; (2) to expand the poplar transformation toolkit by developing transformation methods for important genotypes; and (3) to allow induced expression, and efficient gene suppression, in roots and other tissues. As part of the transformation improvement effort, OSU developed transformation protocols for Populus trichocarpa 'Nisqually-1' clone and an early flowering P. alba clone, 6K10. Complete descriptions of the transformation systems were published (Ma et. al. 2004, Meilan et. al 2004). Twenty-one 'Nisqually-1' and 622 6K10 transgenic plants were generated. To identify root predominant promoters, a set of three promoters were tested for their tissue-specific expression patterns in poplar and in Arabidopsis as a model system. A novel gene, ET304, was identified by analyzing a collection of poplar enhancer trap lines generated at OSU (Filichkin et. al 2006a, 2006b). Other promoters include the pGgMT1 root-predominant promoter from Casuarina glauca and the pAtPIN2 promoter from Arabidopsis root specific PIN2 gene. OSU tested two induction systems, alcohol- and estrogen-inducible, in multiple poplar transgenics. Ethanol proved to be the more efficient when tested in tissue culture and greenhouse conditions. Two estrogen-inducible systems were evaluated in transgenic Populus, neither of which functioned reliably in tissue culture conditions. GATEWAY-compatible plant binary vectors were designed to compare the silencing efficiency of homologous (direct) RNAi vs. heterologous (transitive) RNAi inverted repeats. A set of genes was targeted for post transcriptional silencing in the model Arabidopsis system; these include the floral meristem identity gene (APETALA1 or

  11. A Doctor Talks to 5-to-8-Year Olds.

    ERIC Educational Resources Information Center

    Meilach, Dona Z.; Mandel, Elias

    One of a series of books written by doctors for their patients, this publication gives information about life in casual and straightforward children's language. Birds, fish and other animals are compared to humans and are used as examples to explain conception, birth and the development of babies to adulthood. To illustrate important concepts,…

  12. Rich Discussions by 7- and 8-Year-Olds

    ERIC Educational Resources Information Center

    Kohlfeld, Carol

    2008-01-01

    In the author's second grade maths class, the students were excited and energised after discovering, understanding and learning an advanced mathematical concept. In the class, the second-graders spent a great deal of time discussing how they used the number grid to work out 96 - 7. In this article, the author presents a portion of the class…

  13. Interpreting Weather for 3 to 8 Year Olds.

    ERIC Educational Resources Information Center

    Hallgren-Scaffidi, Lynette

    1994-01-01

    Discusses the interpretation of weather for children and shares program ideas to interpret the water cycle, thunderstorms (including fear of thunderstorms), and rainbows (including the colors of the rainbow). (MKR)

  14. An efficient Agrobacterium-mediated transformation system for poplar.

    PubMed

    Movahedi, Ali; Zhang, Jiaxin; Amirian, Rasoul; Zhuge, Qiang

    2014-06-13

    Poplar is a model system for the regeneration and genetic transformation of woody plants. To shorten the time required for studies of transgenic poplar, efforts have been made to optimize transformation methods that use Agrobacterium tumefaciens. In this study, an Agrobacterium infective suspension was treated at 4 °C for at least 10 h before infecting explants. By transforming the Populus hybrid clone "Nanlin895" (Populus deltoides×P. euramericana) with Agrobacterium harboring the PBI121:CarNAC6 binary vector, we showed that the transformation efficiency was improved significantly by multiple independent factors, including an Agrobacterium infective suspension with an OD600 of 0.7, an Agrobacterium infection for 120 min, an Agrobacterium infective suspension at a pH of 5.0, an acetosyringone concentration of 200 µM, a cocultivation at 28 °C, a cocultivation for 72 h and a sucrose concentration of 30 g/L in the cocultivation medium. We also showed that preculture of wounded leaf explants for two days increased the regeneration rate. The integration of the desired gene into transgenic poplars was detected using selective medium containing kanamycin, followed by southern blot analysis. The expression of the transgene in the transgenic lines was confirmed by northern blot analysis.

  15. Fungal community associated with genetically modified poplar during metal phytoremediation.

    PubMed

    Hur, Moonsuk; Lim, Young Woon; Yu, Jae Jeong; Cheon, Se Uk; Choi, Young Im; Yoon, Seok-Hwan; Park, Sang-Cheol; Kim, Dong-Il; Yi, Hana

    2012-12-01

    Due to the increasing demand for phytoremediation, many transgenic poplars have been developed to enhance the bioremediation of heavy metals. However, structural changes to indigenous fungal communities by genetically modified organisms (GMO) presents a major ecological issue, due to the important role of fungi for plant growth in natural environments. To evaluate the effect of GM plant use on environmental fungal soil communities, extensive sequencing-based community analysis was conducted, while controlling the influence of plant clonality, plant age, soil condition, and harvesting season. The rhizosphere soils of GM and wild type (WT) poplars at a range of growth stages were sampled together with unplanted, contaminated soil, and the fungal community structures were investigated by pyrosequencing the D1/D2 region of the 28S rRNA gene. The results show that the overall structure of the rhizosphere fungal community was not significantly influenced by GM poplars. However, the presence of GM specific taxa, and faster rate of community change during poplar growth, appeared to be characteristic of the GM plant-induced effects on soil-born fungal communities. The results of this study provide additional information about the potential effects of GM poplar trees aged 1.5-3 years, on the soil fungal community.

  16. Poplar trees for phytoremediation of high levels of nitrate and applications in bioenergy.

    PubMed

    Castro-Rodríguez, Vanessa; García-Gutiérrez, Angel; Canales, Javier; Cañas, Rafael A; Kirby, Edward G; Avila, Concepción; Cánovas, Francisco M

    2016-01-01

    The utilization of high amounts of nitrate fertilizers for crop yield leads to nitrate pollution of ground and surface waters. In this study, we report the assimilation and utilization of nitrate luxuriant levels, 20 times more than the highest N fertilizer application in Europe, by transgenic poplars overexpressing a cytosolic glutamine synthetase (GS1). In comparison with the wild-type controls, transgenic plants grown under high N levels exhibited increased biomass (171.6%) and accumulated higher levels of proteins, chlorophylls and total sugars such as glucose, fructose and sucrose. These plants also exhibited greater nitrogen-use efficiency particularly in young leaves, suggesting that they are able to translocate most of the resources to the above-ground part of the plant to produce biomass. The transgenic poplar transcriptome was greatly affected in response to N availability with 1237 genes differentially regulated in high N, while only 632 genes were differentially expressed in untransformed plants. Many of these genes are essential in the adaptation and response against N excess and include those involved in photosynthesis, cell wall formation and phenylpropanoid biosynthesis. Cellulose production in the transgenic plants was fivefold higher than in control plants, indicating that transgenic poplars represent a potential feedstock for applications in bioenergy. In conclusion, our results show that GS transgenic poplars can be used not only for improving growth and biomass production but also as an important resource for potential phytoremediation of nitrate pollution.

  17. Isoprene biosynthesis in hybrid poplar impacts ozone tolerance

    NASA Astrophysics Data System (ADS)

    Behnke, K.; Kleist, E.; Uerlings, R.; Wildt, J.; Rennenberg, H.; Schnitzler, J. P.

    2009-04-01

    Isoprene is the most abundant volatile compound emitted by vegetation. It influences air chemistry and is thought to take part in plant defense reactions against abiotic stress such as high temperature or ozone. However, whether or not isoprene emission interacts with ozone tolerance of plants is still in discussion. We exploited transgenic non-isoprene emitting Grey poplar (Populus x canescens) in a biochemical and physiological model study to investigate the effect of acute ozone stress on the elicitation of defense-related emissions of plant volatiles, photosynthesis and the antioxidative system. We recorded that non-isoprene emitting poplars are more resistant to ozone as indicated by less damaged leaf area and higher assimilation rates compared to ozone-exposed wild type plants. The integral of green leaf volatile (GLV) emissions was different between the two poplar phenotypes and a reliable early marker for subsequent leaf damage. For other stress-induced volatiles like mono-, homo-, and sesquiterpenes, and methyl salicylate similar time profiles, pattern and emission intensities were observed in both transgenic and wild type plants. However, un-stressed non-isoprene emitting poplars are characterized by elevated levels of ascorbate and α-tocopherol as well as a more effective de-epoxidation ratio of xanthophylls than in wild type plants. Since ozone quenching properties of ascorbate are much higher than those of isoprene and furthermore α-tocopherol also is an essential antioxidant, non-isoprene emitting poplars might benefit from changes within the antioxidative system by providing them with enhanced ozone tolerance.

  18. Wood reinforcement of poplar by rice NAC transcription factor

    PubMed Central

    Sakamoto, Shingo; Takata, Naoki; Oshima, Yoshimi; Yoshida, Kouki; Taniguchi, Toru; Mitsuda, Nobutaka

    2016-01-01

    Lignocellulose, composed of cellulose, hemicellulose, and lignin, in the secondary cell wall constitutes wood and is the most abundant form of biomass on Earth. Enhancement of wood accumulation may be an effective strategy to increase biomass as well as wood strength, but currently only limited research has been undertaken. Here, we demonstrated that OsSWN1, the orthologue of the rice NAC Secondary-wall Thickening factor (NST) transcription factor, effectively enhanced secondary cell wall formation in the Arabidopsis inflorescence stem and poplar (Populus tremula×Populus tremuloides) stem when expressed by the Arabidopsis NST3 promoter. Interestingly, in transgenic Arabidopsis and poplar, ectopic secondary cell wall deposition in the pith area was observed in addition to densification of the secondary cell wall in fiber cells. The cell wall content or density of the stem increased on average by up to 38% and 39% in Arabidopsis and poplar, respectively, without causing growth inhibition. As a result, physical strength of the stem increased by up to 57% in poplar. Collectively, these data suggest that the reinforcement of wood by NST3pro:OsSWN1 is a promising strategy to enhance wood-biomass production in dicotyledonous plant species. PMID:26812961

  19. Tissue-type-specific transcriptome analysis identifies developing xylem-specific promoters in poplar.

    PubMed

    Ko, Jae-Heung; Kim, Hyun-Tae; Hwang, Ildoo; Han, Kyung-Hwan

    2012-06-01

    Plant biotechnology offers a means to create novel phenotypes. However, commercial application of biotechnology in crop improvement programmes is severely hindered by the lack of utility promoters (or freedom to operate the existing ones) that can drive gene expression in a tissue-specific or temporally controlled manner. Woody biomass is gaining popularity as a source of fermentable sugars for liquid fuel production. To improve the quantity and quality of woody biomass, developing xylem (DX)-specific modification of the feedstock is highly desirable. To develop utility promoters that can drive transgene expression in a DX-specific manner, we used the Affymetrix Poplar Genome Arrays to obtain tissue-type-specific transcriptomes from poplar stems. Subsequent bioinformatics analysis identified 37 transcripts that are specifically or strongly expressed in DX cells of poplar. After further confirmation of their DX-specific expression using semi-quantitative PCR, we selected four genes (DX5, DX8, DX11 and DX15) for in vivo confirmation of their tissue-specific expression in transgenic poplars. The promoter regions of the selected DX genes were isolated and fused to a β-glucuronidase (GUS)-reported gene in a binary vector. This construct was used to produce transgenic poplars via Agrobacterium-mediated transformation. The GUS expression patterns of the resulting transgenic plants showed that these promoters were active in the xylem cells at early seedling growth and had strongest expression in the developing xylem cells at later growth stages of poplar. We conclude that these DX promoters can be used as a utility promoter for DX-specific biomass engineering.

  20. Enhanced phytoremediation of volatile environmental pollutants with transgenic trees

    PubMed Central

    Doty, Sharon L.; James, C. Andrew; Moore, Allison L.; Vajzovic, Azra; Singleton, Glenda L.; Ma, Caiping; Khan, Zareen; Xin, Gang; Kang, Jun Won; Park, Jin Young; Meilan, Richard; Strauss, Steven H.; Wilkerson, Jasmine; Farin, Federico; Strand, Stuart E.

    2007-01-01

    Small, volatile hydrocarbons, including trichloroethylene, vinyl chloride, carbon tetrachloride, benzene, and chloroform, are common environmental pollutants that pose serious health effects. We have developed transgenic poplar (Populus tremula × Populus alba) plants with greatly increased rates of metabolism and removal of these pollutants through the overexpression of cytochrome P450 2E1, a key enzyme in the metabolism of a variety of halogenated compounds. The transgenic poplar plants exhibited increased removal rates of these pollutants from hydroponic solution. When the plants were exposed to gaseous trichloroethylene, chloroform, and benzene, they also demonstrated superior removal of the pollutants from the air. In view of their large size and extensive root systems, these transgenic poplars may provide the means to effectively remediate sites contaminated with a variety of pollutants at much faster rates and at lower costs than can be achieved with current conventional techniques. PMID:17940038

  1. The poplar basic helix-loop-helix transcription factor BEE3 – Like gene affects biomass production by enhancing proliferation of xylem cells in poplar

    SciTech Connect

    Noh, Seol Ah Choi, Young-Im Cho, Jin-Seong Lee, Hyoshin

    2015-06-19

    Brassinosteroids (BRs) play important roles in many aspects of plant growth and development, including regulation of vascular cambium activities and cell elongation. BR-induced BEE3 (brassinosteroid enhanced expression 3) is required for a proper BR response. Here, we identified a poplar (Populus alba × Populus glandulosa) BEE3-like gene, PagBEE3L, encoding a putative basic helix-loop-helix (bHLH)-type transcription factor. Expression of PagBEE3L was induced by brassinolide (BL). Transcripts of PagBEE3L were mainly detected in stems, with the internode having a low level of transcription and the node having a relatively higher level. The function of the PagBEE3L gene was investigated through phenotypic analyses with PagBEE3L-overexpressing (ox) transgenic lines. This work particularly focused on a potential role of PagBEE3L in stem growth and development of polar. The PagBEE3L-ox poplar showed thicker and longer stems than wild-type plants. The xylem cells from the stems of PagBEE3L-ox plants revealed remarkably enhanced proliferation, resulting in an earlier thickening growth than wild-type plants. Therefore, this work suggests that xylem development of poplar is accelerated in PagBEE3L-ox plants and PagBEE3L plays a role in stem growth by increasing the proliferation of xylem cells to promote the initial thickening growth of poplar stems. - Highlights: • We identify the BEE3-like gene form hybrid poplar (Populus alba × Populus glandulosa). • We examine effects of overexpression of PagBEE3L on growth in poplar. • We found that 35S:BEE3L transgenic plants showed more rapid growth than wild-type plants. • BEE3L protein plays an important role in the development of plant stem.

  2. Effect of Genetically Modified Poplars on Soil Microbial Communities during the Phytoremediation of Waste Mine Tailings▿†

    PubMed Central

    Hur, Moonsuk; Kim, Yongho; Song, Hae-Ryong; Kim, Jong Min; Choi, Young Im; Yi, Hana

    2011-01-01

    The application of transgenic plants to clean up environmental pollution caused by the wastes of heavy metal mining is a promising method for removing metal pollutants from soils. However, the effect of using genetically modified organisms for phytoremediation is a poorly researched topic in terms of microbial community structures, despite the important role of microorganisms in the health of soil. In this study, a comparative analysis of the bacterial and archaeal communities found in the rhizosphere of genetically modified (GM) versus wild-type (WT) poplar was conducted on trees at different growth stages (i.e., the rhizospheres of 1.5-, 2.5-, and 3-year-old poplars) that were cultivated on contaminated soils together with nonplanted control soil. Based on the results of DNA pyrosequencing, poplar type and growth stages were associated with directional changes in the structure of the microbial community. The rate of change was faster in GM poplars than in WT poplars, but the microbial communities were identical in the 3-year-old poplars. This phenomenon may arise because of a higher rate and greater extent of metal accumulation in GM poplars than in naturally occurring plants, which resulted in greater changes in soil environments and hence the microbial habitat. PMID:21890678

  3. Overexpression of poplar cellulase accelerates growth and disturbs the closing movements of leaves in sengon.

    PubMed

    Hartati, Sri; Sudarmonowati, Enny; Park, Yong Woo; Kaku, Tomomi; Kaida, Rumi; Baba, Kei'ichi; Hayashi, Takahisa

    2008-06-01

    In this study, poplar (Populus alba) cellulase (PaPopCel1) was overexpressed in a tropical Leguminosae tree, sengon (Paraserianthes falcataria), by the Agrobacterium tumefaciens method. PaPopCel1 overexpression increased the length and width of stems with larger leaves, which showed a moderately higher density of green color than leaves of the wild type. The pairs of leaves on the transgenic plants closed more slowly during sunset than those on the wild-type plants. When main veins from each genotype were excised and placed on a paper towel, however, the leaves of the transgenic plants closed more rapidly than those of the wild-type plant. Based on carbohydrate analyses of cell walls, the leaves of the transgenic plants contained less wall-bound xyloglucan than those of the wild-type plants. In situ xyloglucan endotransglucosylase activity showed that the incorporation of whole xyloglucan, potentially for wall tightening, occurred in the parenchyma cells (motor cells) of the petiolule pulvinus attached to the main vein, although the transgenic plant incorporated less whole xyloglucan than the wild-type plant. These observations support the hypothesis that the paracrystalline sites of cellulose microfibrils are attacked by poplar cellulase, which loosens xyloglucan intercalation, resulting in an irreversible wall modification. This process could be the reason why the overexpression of poplar cellulase both promotes plant growth and disturbs the biological clock of the plant by altering the closing movements of the leaves of the plant. PMID:18417637

  4. Efficient Agrobacterium-mediated transformation of commercial hybrid poplar Populus nigra L. x P. maximowiczii A. Henry.

    PubMed

    Yevtushenko, Dmytro P; Misra, Santosh

    2010-03-01

    Many economically important species of Populus, especially those in sections Aigeiros and Tacamahaca, remain recalcitrant to genetic transformation. In this study, a simple and reliable protocol was developed for the efficient Agrobacterium-mediated transformation of a difficult-to-transform, but commercially viable, hybrid poplar Populus nigra L. x P. maximowiczii A. Henry (NM6). A plant transformation vector designed to express the beta-glucuronidase (GUS) gene was used to detect transformation events at early stages of plant regeneration and to optimize parameters affecting poplar transformation. The use of zeatin riboside in shoot-induction medium, regeneration of shoots via indirect organogenesis, and early selection pressure were the major modifications that drastically improved the efficiency of poplar transformation and minimized the number of untransformed regenerants. Transgenic shoots were routinely obtained 4-10 weeks after co-culture with A. tumefaciens, with a greater than 90% rate of plant recovery. Stable transgene integration, ranging from a single insertion to ten copies per genome, was confirmed by Southern blot analysis. The mean transformation frequency was 36.3% and about two-thirds of the lines had 1-2 transgene copies. Among the explants, petioles and leaves had a higher transformation frequency than did stem segments. Growth characteristics and the morphology of transgenic poplar plants were identical to untransformed controls. These findings will accelerate the development of P. nigra x P. maximowiczii plants with novel traits, and may also be useful to improve transformation procedures for other Populus species.

  5. CsRAV1 induces sylleptic branching in hybrid poplar.

    PubMed

    Moreno-Cortés, Alicia; Hernández-Verdeja, Tamara; Sánchez-Jiménez, Paloma; González-Melendi, Pablo; Aragoncillo, Cipriano; Allona, Isabel

    2012-04-01

    • Sylleptic branching in trees may increase significantly branch number, leaf area and the general growth of the tree, particularly in its early years. Although this is a very important trait, so far little is known about the genes that control this process. • This article characterizes the Castanea sativa RAV1 gene, homologous to Arabidopsis TEM genes, by analyzing its circadian behavior and examining its winter expression in chestnut stems and buds. Transgenic hybrid poplars over-expressing CsRAV1 or showing RNA interference down-regulated PtaRAV1 and PtaRAV2 expression were produced and analyzed. • Over-expression of the CsRAV1 gene induces the early formation of sylleptic branches in hybrid poplar plantlets during the same growing season in which the lateral buds form. Only minor growth differences and no changes in wood anatomy are produced. • The possibility of generating trees with a greater biomass by manipulating the CsRAV1 gene makes CsRAV1 transgenic plants promising candidates for bioenergy production.

  6. Investigation of horizontal gene transfer in poplar/Amanita muscaria ectomycorrhizas.

    PubMed

    Zhang, Chi; Hampp, Rüdiger; Nehls, Uwe

    2005-01-01

    Fine roots of forest trees form together with certain soil fungi symbiotic structures (ectomycorrhizas), where fungal hyphae are in intimate contact with plant cells. Due to root cell degeneration, plant DNA is released and could be taken up by the fungus. The possibility that horizontal gene transfer might result in a risk for the environment should be evaluated before a massive release of genetically engineered trees into nature occurs, even though only a few convincing examples of horizontal gene transfer are known. Transgenic poplars containing a construct of the Streptomyces hygroscopicus bar gene under the control of the Cochliobolus heterostrophus GPD (glyceraldehyde-3-phosphate dehydrogenase) promoter were generated by Agrobacterium-mediated transformation. The functionality of this construct in the ectomycorrhizal model fungus Amanita muscaria was previously verified by protoplast-based fungal transformation. 35,000 ectomycorrhizas, formed between transgenic poplars and non-transgenic A. muscaria hyphae, were isolated and transferred to selective agar plates. Putative herbicide-resistant fungal colonies were obtained after the first round of selection. However, none of these colonies survived a transfer onto fresh selection medium, nor did they contain the bar gene, indicating that no horizontal gene transfer from poplar to A. muscaria occurred during symbiosis under axenic conditions. However, since ectomycorrhizas are associated under natural conditions with viruses, bacteria and other fungi, these additional associations should be evaluated in future. PMID:16827551

  7. Differential expression profiles of poplar MAP kinase kinases in response to abiotic stresses and plant hormones, and overexpression of PtMKK4 improves the drought tolerance of poplar.

    PubMed

    Wang, Lei; Su, Hongyan; Han, Liya; Wang, Chuanqi; Sun, Yanlin; Liu, Fenghong

    2014-07-15

    Mitogen-activated protein kinase (MAPK) cascades are universal signal transduction modules that play essential roles in plant growth, development and stress response. MAPK kinases (MAPKKs), which link MAPKs and MAPKK kinases (MAPKKKs), are integral in mediating various stress responses in plants. However, to date few data about the roles of poplar MAPKKs in stress signal transduction are available. In this study, we performed a systemic analysis of poplar MAPKK gene family expression profiles in response to several abiotic stresses and stress-associated hormones. Furthermore, Populus trichocarpa MAPKK4 (PtMKK4) was chosen for functional characterization. Transgenic analysis showed that overexpression of the PtMKK4 gene remarkably enhanced drought stress tolerance in the transgenic poplar plants. The PtMKK4-overexpressing plants also exhibited much lower levels of H2O2 and higher antioxidant enzyme activity after exposure to drought stress compared to the wide type lines. Besides, some drought marker genes including PtP5CS, PtSUS3, PtLTP3 and PtDREB8 exhibited higher expression levels in the transgenic lines than in the wide type under drought conditions. This study provided valuable information for understanding the putative functions of poplar MAPKKs involved in important signaling pathways under different stress conditions.

  8. Isoprene in poplar emissions: effects on new particle formation and OH concentrations

    NASA Astrophysics Data System (ADS)

    Kiendler-Scharr, A.; Andres, S.; Bachner, M.; Behnke, K.; Broch, S.; Hofzumahaus, A.; Holland, F.; Kleist, E.; Mentel, T. F.; Rubach, F.; Springer, M.; Steitz, B.; Tillmann, R.; Wahner, A.; Schnitzler, J.-P.; Wildt, J.

    2011-08-01

    Stress-induced volatile organic compound (VOC) emissions from transgenic Grey poplar, modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA) formation. Nucleation rates of up to 3600 cm-3 s-1 were observed in our experiments. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m-2 s-1 in non-transgenic controls (wild type WT) and nearly zero (<0.5 nmol m-2 s-1) in isoprene emission-repressed lines (line RA22), respectively. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C5D8) was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3 % of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

  9. Isoprene in poplar emissions: effects on new particle formation and OH concentrations

    NASA Astrophysics Data System (ADS)

    Kiendler-Scharr, A.; Andres, S.; Bachner, M.; Behnke, K.; Broch, S.; Hofzumahaus, A.; Holland, F.; Kleist, E.; Mentel, T. F.; Rubach, F.; Springer, M.; Steitz, B.; Tillmann, R.; Wahner, A.; Schnitzler, J.-P.; Wildt, J.

    2012-01-01

    Stress-induced volatile organic compound (VOC) emissions from transgenic Grey poplar modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA) formation. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m-2 s-1 in non-transgenic controls (wild type WT) and nearly zero (<0.5 nmol m-2 s-1) in isoprene emission-repressed plants (line RA22), respectively. Nucleation rates of up to 3600 cm-3 s-1 were observed in our experiments. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C5D8) was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3% of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

  10. DOWNREGULATION OF CINNAMOYL-COENZYME A REDUCTASE IN POPLAR: MULTIPLE-LEVEL PHENOTYPING REVEALS EFFECTS ON CELL WALL POLYMER METABOLISM AND STRUCTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cinnamoyl-CoA reductase catalyzes the penultimate step in monolignol biosynthesis. Here, we report on the generation of transgenic poplars down-regulated for CCR and the molecular and growth characteristics of these transformants. CCR down-regulation was associated with up to 50% reduced lignin cont...

  11. Finding Fingerprints of Selection in Poplar Genomes

    ScienceCinema

    Tuskan, Gerald

    2016-07-12

    Jerry Tuskan of Oak Ridge National Laboratory and the DOE JGI talks about poplar trees as models for selective adaptation to an environment. This video complements a study published ahead online August 24, 2014 in Nature Genetics.

  12. Finding Fingerprints of Selection in Poplar Genomes

    SciTech Connect

    Tuskan, Gerald

    2014-10-02

    Jerry Tuskan of Oak Ridge National Laboratory and the DOE JGI talks about poplar trees as models for selective adaptation to an environment. This video complements a study published ahead online August 24, 2014 in Nature Genetics.

  13. Continuous steam hydrolysis of tulip poplar

    SciTech Connect

    Fieber, C.A.; Roberts, R.S.; Faass, G.S.; Muzzy, J.D.; Colcord, A.R.; Bery, M.K.

    1982-01-01

    The continuous hydrolysis of poplar chips by steam at 300-350 psi resulted in the separation of hemicellulose (I) cellulose and lignin components. The I fraction was readily depolymerised by steam to acetic acid, furfural, methanol, and xylose.

  14. PoplarGene: poplar gene network and resource for mining functional information for genes from woody plants.

    PubMed

    Liu, Qi; Ding, Changjun; Chu, Yanguang; Chen, Jiafei; Zhang, Weixi; Zhang, Bingyu; Huang, Qinjun; Su, Xiaohua

    2016-01-01

    Poplar is not only an important resource for the production of paper, timber and other wood-based products, but it has also emerged as an ideal model system for studying woody plants. To better understand the biological processes underlying various traits in poplar, e.g., wood development, a comprehensive functional gene interaction network is highly needed. Here, we constructed a genome-wide functional gene network for poplar (covering ~70% of the 41,335 poplar genes) and created the network web service PoplarGene, offering comprehensive functional interactions and extensive poplar gene functional annotations. PoplarGene incorporates two network-based gene prioritization algorithms, neighborhood-based prioritization and context-based prioritization, which can be used to perform gene prioritization in a complementary manner. Furthermore, the co-functional information in PoplarGene can be applied to other woody plant proteomes with high efficiency via orthology transfer. In addition to poplar gene sequences, the webserver also accepts Arabidopsis reference gene as input to guide the search for novel candidate functional genes in PoplarGene. We believe that PoplarGene (http://bioinformatics.caf.ac.cn/PoplarGene and http://124.127.201.25/PoplarGene) will greatly benefit the research community, facilitating studies of poplar and other woody plants. PMID:27515999

  15. PoplarGene: poplar gene network and resource for mining functional information for genes from woody plants

    PubMed Central

    Liu, Qi; Ding, Changjun; Chu, Yanguang; Chen, Jiafei; Zhang, Weixi; Zhang, Bingyu; Huang, Qinjun; Su, Xiaohua

    2016-01-01

    Poplar is not only an important resource for the production of paper, timber and other wood-based products, but it has also emerged as an ideal model system for studying woody plants. To better understand the biological processes underlying various traits in poplar, e.g., wood development, a comprehensive functional gene interaction network is highly needed. Here, we constructed a genome-wide functional gene network for poplar (covering ~70% of the 41,335 poplar genes) and created the network web service PoplarGene, offering comprehensive functional interactions and extensive poplar gene functional annotations. PoplarGene incorporates two network-based gene prioritization algorithms, neighborhood-based prioritization and context-based prioritization, which can be used to perform gene prioritization in a complementary manner. Furthermore, the co-functional information in PoplarGene can be applied to other woody plant proteomes with high efficiency via orthology transfer. In addition to poplar gene sequences, the webserver also accepts Arabidopsis reference gene as input to guide the search for novel candidate functional genes in PoplarGene. We believe that PoplarGene (http://bioinformatics.caf.ac.cn/PoplarGene and http://124.127.201.25/PoplarGene) will greatly benefit the research community, facilitating studies of poplar and other woody plants. PMID:27515999

  16. The poplar basic helix-loop-helix transcription factor BEE3 - Like gene affects biomass production by enhancing proliferation of xylem cells in poplar.

    PubMed

    Noh, Seol Ah; Choi, Young-Im; Cho, Jin-Seong; Lee, Hyoshin

    2015-06-19

    Brassinosteroids (BRs) play important roles in many aspects of plant growth and development, including regulation of vascular cambium activities and cell elongation. BR-induced BEE3 (brassinosteroid enhanced expression 3) is required for a proper BR response. Here, we identified a poplar (Populus alba × Populus glandulosa) BEE3-like gene, PagBEE3L, encoding a putative basic helix-loop-helix (bHLH)-type transcription factor. Expression of PagBEE3L was induced by brassinolide (BL). Transcripts of PagBEE3L were mainly detected in stems, with the internode having a low level of transcription and the node having a relatively higher level. The function of the PagBEE3L gene was investigated through phenotypic analyses with PagBEE3L-overexpressing (ox) transgenic lines. This work particularly focused on a potential role of PagBEE3L in stem growth and development of polar. The PagBEE3L-ox poplar showed thicker and longer stems than wild-type plants. The xylem cells from the stems of PagBEE3L-ox plants revealed remarkably enhanced proliferation, resulting in an earlier thickening growth than wild-type plants. Therefore, this work suggests that xylem development of poplar is accelerated in PagBEE3L-ox plants and PagBEE3L plays a role in stem growth by increasing the proliferation of xylem cells to promote the initial thickening growth of poplar stems.

  17. The MYB182 Protein Down-Regulates Proanthocyanidin and Anthocyanin Biosynthesis in Poplar by Repressing Both Structural and Regulatory Flavonoid Genes1[OPEN

    PubMed Central

    Yoshida, Kazuko; Ma, Dawei; Constabel, C. Peter

    2015-01-01

    Trees in the genus Populus (poplar) contain phenolic secondary metabolites including the proanthocyanidins (PAs), which help to adapt these widespread trees to diverse environments. The transcriptional activation of PA biosynthesis in response to herbivory and ultraviolet light stress has been documented in poplar leaves, and a regulator of this process, the R2R3-MYB transcription factor MYB134, has been identified. MYB134-overexpressing transgenic plants show a strong high-PA phenotype. Analysis of these transgenic plants suggested the involvement of additional MYB transcription factors, including repressor-like MYB factors. Here, MYB182, a subgroup 4 MYB factor, was found to act as a negative regulator of the flavonoid pathway. Overexpression of MYB182 in hairy root culture and whole poplar plants led to reduced PA and anthocyanin levels as well as a reduction in the expression of key flavonoid genes. Similarly, a reduced accumulation of transcripts of a MYB PA activator and a basic helix-loop-helix cofactor was observed in MYB182-overexpressing hairy roots. Transient promoter activation assays in poplar cell culture demonstrated that MYB182 can disrupt transcriptional activation by MYB134 and that the basic helix-loop-helix-binding motif of MYB182 was essential for repression. Microarray analysis of transgenic plants demonstrated that down-regulated targets of MYB182 also include shikimate pathway genes. This work shows that MYB182 plays an important role in the fine-tuning of MYB134-mediated flavonoid metabolism. PMID:25624398

  18. Gain-of-function analysis of poplar CLE genes in Arabidopsis by exogenous application and over-expression assays.

    PubMed

    Liu, Yisen; Yang, Shaohui; Song, Yingjin; Men, Shuzhen; Wang, Jiehua

    2016-04-01

    Among 50 CLE gene family members in the Populus trichocarpa genome, three and six PtCLE genes encode a CLE motif sequence highly homologous to Arabidopsis CLV3 and TDIF peptides, respectively, which potentially make them functional equivalents. To test and compare their biological activity, we first chemically synthesized each dodecapeptide and analysed itsi n vitro bioactivity on Arabidopsis seedlings. Similarly, but to a different extent, three types of poplar CLV3-related peptides caused root meristem consumption, phyllotaxis disorder, anthocyanin accumulation and failure to enter the bolting stage. In comparison, application of two poplar TDIF-related peptides led to root length promotion in a dose-dependent manner with an even stronger effect observed for poplar TDIF-like peptide than TDIF. Next, we constructed CaMV35S:PtCLE transgenic plants for each of the nine PtCLE genes. Phenotypic abnormalities exemplified by arrested shoot apical meristem and abnormal flower structure were found to be more dominant and severe in 35S:PtCLV3 and 35S:PtCLV3-like2 lines than in the 35S:PtCLV3-like line. Disordered vasculature was detected in both stem and hypocotyl cross-sections in Arabidopsis plants over-expressing poplar TDIF-related genes with the most defective vascular patterning observed for TDIF2 and two TDIF-like genes. Phenotypic difference consistently observed in peptide application assay and transgenic analysis indicated the functional diversity of nine poplar PtCLE genes under investigation. This work represents the first report on the functional analysis of CLE genes in a tree species and constitutes a basis for further study of the CLE peptide signalling pathway in tree development. PMID:26912800

  19. Interference between oculomotor and postural tasks in 7-8-year-old children and adults.

    PubMed

    Legrand, Agathe; Doré Mazars, Karine; Lemoine, Christelle; Nougier, Vincent; Olivier, Isabelle

    2016-06-01

    Several studies in adults having observed the effect of eye movements on postural control provided contradictory results. In the present study, we explored the effect of various oculomotor tasks on postural control and the effect of different postural tasks on eye movements in eleven children (7.8 ± 0.5 years) and nine adults (30.4 ± 6.3 years). To vary the difficulty of the oculomotor task, three conditions were tested: fixation, prosaccades (reactive saccades made toward the target) and antisaccades (voluntary saccades made in the direction opposite to the visual target). To vary the difficulty of postural control, two postural tasks were tested: Standard Romberg (SR) and Tandem Romberg (TR). Postural difficulty did not affect oculomotor behavior, except by lengthening adults' latencies in the prosaccade task. For both groups, postural control was altered in the antisaccade task as compared to fixation and prosaccade tasks. Moreover, a ceiling effect was found in the more complex postural task. This study highlighted a cortical interference between oculomotor and postural control systems.

  20. Subclinical fungal endometritis in an 8-year-old Hanoverian mare

    PubMed Central

    Aitken, Gregory J.

    2012-01-01

    Clinical and subclinical endometritis are leading causes of reduced reproductive efficiency in the mare. Clinical endometritis is relatively easy to diagnose during routine physical and ultrasonographic reproductive examinations, whereas the diagnosis of subclinical endometritis requires a more detailed work-up. The goal of this paper is to review the various options, and describe the regimen chosen in a mare with subclinical fungal endometritis. PMID:22851785

  1. Speech Characteristics of 8-Year-Old Children: Findings from a Prospective Population Study

    ERIC Educational Resources Information Center

    Wren, Yvonne; McLeod, Sharynne; White, Paul; Miller, Laura L.; Roulstone, Sue

    2013-01-01

    Speech disorder that continues into middle childhood is rarely studied compared with speech disorder in the early years. Speech production in single words, connected speech and nonword repetition was assessed for 7390 eight-year-old children within the Avon Longitudinal Study of Parents and Children (ALSPAC). The majority (n=6399) had typical…

  2. Teaching Number in the Classroom with 4-8 Year-Olds

    ERIC Educational Resources Information Center

    Wright, Robert J.; Stanger, Garry; Stafford, Ann K.; Martland, Jim

    2006-01-01

    This book sets out a constructivist, inquiry-based approach to instruction. The approach builds on clear understandings of children's current levels of knowledge, where their learning should progress to, and the means by which children learn early numeracy topics. The methods presented in this book have been used extensively by practitioners in…

  3. Content analysis of 4 to 8 year-old children's dream reports.

    PubMed

    Sándor, Piroska; Szakadát, Sára; Kertész, Katinka; Bódizs, Róbert

    2015-01-01

    The role of dreaming in childhood and in adulthood are still equally enigmatic fields yet to be fully explored. However, while there is a consensus at least about the typical content and formal characteristics of adult dream reports, these features are still a matter of debate in the case of young children. Longitudinal developmental laboratory studies concluded that preschoolers' dreams usually depict static images about mostly animals and body states of the dreamer but they basically lack the active representation of the self, human characters, social interactions, dream emotions and motion imagery. Due to methodological arguments these results became the reference points in the literature of developmental dream research, in spite of the significantly different results of numerous recent and relevant studies using extra-laboratory settings. This study aims to establish a methodologically well-controlled and valid way to collect children's dreams for a representative period of time in a familiar home setting to serve as a comparison to the laboratory method. Pre trained parents acted as interviewers in the course of a 6 week-period of dream collection upon morning awakenings. Our results suggest that even preschoolers are likely to represent their own self in an active role (70%) in their mostly kinematic (82%) dream narratives. Their dream reports contain more human, than animal characters (70 and 7% of all dream characters respectively), and social interactions, self-initiated actions, and emotions are usual part of these dreams. These results are rather similar to those of recent extra-laboratory studies, suggesting that methodological issues may strongly interfere with research outcomes especially in the case of preschoolers' dream narratives. We suggest that nighttime awakenings in the laboratory setting could be crucial in understanding the contradictory results of dream studies in case of young children. PMID:25983708

  4. Contextualised Learning for 5- 8-Year-Olds. 5-14 Teacher Support Series.

    ERIC Educational Resources Information Center

    Fabian, Hilary

    Noting that play provides opportunities for children to develop adaptability, flexibility, and creativity, this paper links the findings of educational research on play and the work of teachers in primary classrooms in Scotland following the 5-14 curriculum. The paper's introduction provides information on historical and contemporary theories of…

  5. Face Adaptation and Attractiveness Aftereffects in 8-Year-Olds and Adults

    ERIC Educational Resources Information Center

    Anzures, Gizelle; Mondloch, Catherine J.; Lackner, Christine

    2009-01-01

    A novel method was used to investigate developmental changes in face processing: attractiveness aftereffects. Consistent with the norm-based coding model, viewing consistently distorted faces shifts adults' attractiveness preferences toward the adapting stimuli. Thus, adults' attractiveness judgments are influenced by a continuously updated face…

  6. Content analysis of 4 to 8 year-old children's dream reports

    PubMed Central

    Sándor, Piroska; Szakadát, Sára; Kertész, Katinka; Bódizs, Róbert

    2015-01-01

    The role of dreaming in childhood and in adulthood are still equally enigmatic fields yet to be fully explored. However, while there is a consensus at least about the typical content and formal characteristics of adult dream reports, these features are still a matter of debate in the case of young children. Longitudinal developmental laboratory studies concluded that preschoolers' dreams usually depict static images about mostly animals and body states of the dreamer but they basically lack the active representation of the self, human characters, social interactions, dream emotions and motion imagery. Due to methodological arguments these results became the reference points in the literature of developmental dream research, in spite of the significantly different results of numerous recent and relevant studies using extra-laboratory settings. This study aims to establish a methodologically well-controlled and valid way to collect children's dreams for a representative period of time in a familiar home setting to serve as a comparison to the laboratory method. Pre trained parents acted as interviewers in the course of a 6 week-period of dream collection upon morning awakenings. Our results suggest that even preschoolers are likely to represent their own self in an active role (70%) in their mostly kinematic (82%) dream narratives. Their dream reports contain more human, than animal characters (70 and 7% of all dream characters respectively), and social interactions, self-initiated actions, and emotions are usual part of these dreams. These results are rather similar to those of recent extra-laboratory studies, suggesting that methodological issues may strongly interfere with research outcomes especially in the case of preschoolers' dream narratives. We suggest that nighttime awakenings in the laboratory setting could be crucial in understanding the contradictory results of dream studies in case of young children. PMID:25983708

  7. Teaching 4- to 8-Year-Olds: Literacy, Math, Multiculturalism, and Classroom Community.

    ERIC Educational Resources Information Center

    Howes, Carollee

    The next decade will see a dramatic increase in public finding for programs serving young children. Prekindergarten and early elementary programs will received more scrutiny in line with a growing awareness that school success is heavily influenced by the skills and attitudes children have when they enter school and quality of initial school…

  8. Associations among different orofacial dysfunctions in 6-8 year olds.

    PubMed

    Laine, M T; Pahkala, R H; Jaroma, S M; Qvarnström, M J

    1992-11-01

    Associations among several orofacial dysfunctions such as articulatory speech disorders, craniomandibular disorders (CMD) and problems in coordinating the orofacial muscles were examined in two groups of Finnish first-graders, i.e. children with and without speech disorders. In the whole sample of 287 subjects the mean age was 7.5 yr. A speech therapist diagnosed articulatory speech disorders and a phoniatrician examined the morphology and function of the articulators. Signs and symptoms of CMD, capacity for mandibular movement, and prevalence of occlusal interferences were examined by a dentist. Deviations in motor skills, but not in morphology of the articulators, were associated with speech disorders. The findings also suggested that capacity for mandibular movement, deviation of the jaw during maximal mouth opening and occlusal interferences were related to certain speech disorders among these 6-8 yr olds. Different orofacial dysfunctions appear to be associated with each other during growth. PMID:1466638

  9. Magnesium metabolism in 4-year-old to 8-year-old children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Magnesium (Mg) is a key factor in bone health, but few studies have evaluated Mg intake or absorption and their relationship with bone mineral content (BMC) or bone mineral density (BMD) in children. We measured Mg intake, absorption, and urinary excretion in a group of children 4 to 8 years of age....

  10. Challenges of banding jejunal varices in an 8-year-old child

    PubMed Central

    Belsha, Dalia; Thomson, Mike

    2015-01-01

    Endoscoic variceal ligation (EVL) by the application of bands on small bowel varices is a relatively rare procedure in gastroenterology and hepatology. There are no previously reported paediatric cases of EVL for jejunal varices. We report a case of an eight-year-old male patient with a complex surgical background leading to jejunal varices and short bowel syndrome, presenting with obscure but profound acute gastrointestinal bleeding. Wireless capsule endoscopy and double balloon enteroscopy (DBE) confirmed jejunal varices as the source of bleeding. The commercially available variceal banding devices are not long enough to be used either with DBE or with push enteroscopes. With the use of an operating gastroscope, four bands were placed successfully on the afferent and efferent ends of the leads of the 2 of the varices. Initial hemostasis was achieved with obliteration of the varices after three separate applications. This case illustrates the feasibility of achieving initial hemostasis in the pediatric population. PMID:26722617

  11. Explaining Variability: Numerical Representations in 4- to 8-Year-Old Children

    ERIC Educational Resources Information Center

    Friso-van den Bos, Ilona; Kolkman, Meijke E.; Kroesbergen, Evelyn H.; Leseman, Paul P. M.

    2014-01-01

    The present study aims to examine relations between number representations and various sources of individual differences within early stages of development of number representations. The mental number line has been found to develop from a logarithmic to a more linear representation. Sources under investigation are counting skills and executive…

  12. Speech Reading and Learning to Read: A Comparison of 8-Year-Old

    ERIC Educational Resources Information Center

    Harris, Margaret; Moreno, Constanza

    2006-01-01

    Nine children with severe-profound prelingual hearing loss and single-word reading scores not more than 10 months behind chronological age (Good Readers) were matched with 9 children whose reading lag was at least 15 months (Poor Readers). Good Readers had significantly higher spelling and reading comprehension scores. They produced significantly…

  13. Associations among different orofacial dysfunctions in 6-8 year olds.

    PubMed

    Laine, M T; Pahkala, R H; Jaroma, S M; Qvarnström, M J

    1992-11-01

    Associations among several orofacial dysfunctions such as articulatory speech disorders, craniomandibular disorders (CMD) and problems in coordinating the orofacial muscles were examined in two groups of Finnish first-graders, i.e. children with and without speech disorders. In the whole sample of 287 subjects the mean age was 7.5 yr. A speech therapist diagnosed articulatory speech disorders and a phoniatrician examined the morphology and function of the articulators. Signs and symptoms of CMD, capacity for mandibular movement, and prevalence of occlusal interferences were examined by a dentist. Deviations in motor skills, but not in morphology of the articulators, were associated with speech disorders. The findings also suggested that capacity for mandibular movement, deviation of the jaw during maximal mouth opening and occlusal interferences were related to certain speech disorders among these 6-8 yr olds. Different orofacial dysfunctions appear to be associated with each other during growth.

  14. Magnesium metabolism in 4-year-old to 8-year-old children.

    PubMed

    Abrams, Steven A; Chen, Zhensheng; Hawthorne, Keli M

    2014-01-01

    Magnesium (Mg) is a key factor in bone health, but few studies have evaluated Mg intake or absorption and their relationship with bone mineral content (BMC) or bone mineral density (BMD) in children. We measured Mg intake, absorption, and urinary excretion in a group of children 4 to 8 years of age. Mg absorption was determined using a dual-tracer stable isotope technique, with (25) Mg given intravenously and (26) Mg given orally. We found a small, but significantly greater Mg absorption efficiency (percentage absorption) in males than females (67% ± 12% versus 60% ± 8%, p = 0.02) but no difference in estimated net Mg retention (average of 37 mg/d in both males and females). Relating dietary Mg intake to estimated Mg retention showed that an intake of 133 mg/d, slightly above the current estimated average requirement (EAR) of 110 mg/d, led to a net average retention of 10 mg/d, the likely minimum growth-related need for this age group. Covariate analysis showed that Mg intake and total Mg absorption, but not calcium intake or total absorption were significantly associated with both total body BMC and BMD. These results suggest that usual Mg intakes in small children in the United States meet dietary requirements in most but not all children. Within the usual range of children's diets in the United States, dietary Mg intake and absorption may be important, relatively unrecognized factors in bone health.

  15. Biotechnology and poplars: A US perspective

    SciTech Connect

    Layton, P.; Ostry, M.E.

    1988-01-01

    An increasing number of researchers are investigating Populus spp. using biotechnical research techniques. Its commercial importance, genome size, and relative ease of propagation from cell and tissue culture are contributing to the increase. Significant progress has been made in refining cell and tissue culture methods and identifying the associated genetic variability. Researchers have identified somaclones with acceptable tolerance levels to several herbicides and diseases. Genetic transformation of poplars has progressed with the development of several gene transfer methods (Agrobacterium, electroporation, and microprojectiles) and the incorporation of commercially important genes (aroA and potato inhibitor II). Research on gene promoters has progressed, and two putative wound inducible promoters have been identified in hybrid poplar. Although federal research dollars in FY 1989 are low for forest biotechnology, research is continuing. Federal research dollars may rise again in 1990 to aid the exploitation of biotechnology to enhance poplar growth and production, especially for use as energy feedstocks. 13 refs., 1 fig.

  16. RNAi-mediated downregulation of poplar plasma membrane intrinsic proteins (PIPs) changes plasma membrane proteome composition and affects leaf physiology.

    PubMed

    Bi, Zhen; Merl-Pham, Juliane; Uehlein, Norbert; Zimmer, Ina; Mühlhans, Stefanie; Aichler, Michaela; Walch, Axel Karl; Kaldenhoff, Ralf; Palme, Klaus; Schnitzler, Jörg-Peter; Block, Katja

    2015-10-14

    Plasma membrane intrinsic proteins (PIPs) are one subfamily of aquaporins that mediate the transmembrane transport of water. To reveal their function in poplar, we generated transgenic poplar plants in which the translation of PIP genes was downregulated by RNA interference investigated these plants with a comprehensive leaf plasma membrane proteome and physiome analysis. First, inhibition of PIP synthesis strongly altered the leaf plasma membrane protein composition. Strikingly, several signaling components and transporters involved in the regulation of stomatal movement were differentially regulated in transgenic poplars. Furthermore, hormonal crosstalk related to abscisic acid, auxin and brassinosteroids was altered, in addition to cell wall biosynthesis/cutinization, the organization of cellular structures and membrane trafficking. A physiological analysis confirmed the proteomic results. The leaves had wider opened stomata and higher net CO2 assimilation and transpiration rates as well as greater mesophyll conductance for CO2 (gm) and leaf hydraulic conductance (Kleaf). Based on these results, we conclude that PIP proteins not only play essential roles in whole leaf water and CO2 flux but have important roles in the regulation of stomatal movement. PMID:26248320

  17. Transgenic Animals.

    ERIC Educational Resources Information Center

    Jaenisch, Rudolf

    1988-01-01

    Describes three methods and their advantages and disadvantages for introducing genes into animals. Discusses the predictability and tissue-specificity of the injected genes. Outlines the applications of transgenic technology for studying gene expression, the early stages of mammalian development, mutations, and the molecular nature of chromosomes.…

  18. Enhanced resistance to fungal pathogens in transgenic Populus tomentosa Carr. by overexpression of an nsLTP-like antimicrobial protein gene from motherwort (Leonurus japonicus).

    PubMed

    Jia, Zhichun; Gou, Jiqing; Sun, Yimin; Yuan, Li; Tang, Qiao; Yang, Xingyong; Pei, Yan; Luo, Keming

    2010-12-01

    The antimicrobial protein gene LJAMP2 is a plant non-specific lipid transfer protein from motherwort (Leonurus japonicus). In this study, it was introduced into Chinese white poplar (Populus tomentosa Carr.) via Agrobacterium-mediated transformation with neomycin phosphotransferase II gene conferring kanamycin resistance as selectable marker. A total of 16 poplar lines were obtained, and polymerase chain reaction (PCR) analysis established the stable integration of transgenes in the plant genome. Reverse transcription-PCR detected LJAMP2 expression in transgenic plants. Resistance to fungal pathogens Alternaria alternata (Fr.) Keissler and Colletotrichum gloeosporioides (Penz.) of transgenic poplar lines was tested. In vitro inhibitory activity against the fungal pathogens was evident from the crude leaf extracts from the transformants. In vivo assays showed that, after infection with both A. alternata (Fr.) Keissler and C. gloeosporioides (Penz.), there was a significant reduction in disease symptoms in transgenic poplar plants compared with the control. These results suggest that constitutive expression of the LJAMP2 gene from motherwort can be exploited to improve resistance to fungal pathogens in poplar.

  19. Down-regulation of plasma intrinsic protein1 aquaporin in poplar trees is detrimental to recovery from embolism.

    PubMed

    Secchi, Francesca; Zwieniecki, Maciej A

    2014-04-01

    During their lifecycles, trees encounter multiple events of water stress that often result in embolism formation and temporal decreases in xylem transport capacity. The restoration of xylem transport capacity requires changes in cell metabolic activity and gene expression. Specifically, in poplar (Populus spp.), the formation of xylem embolisms leads to a clear up-regulation of plasma membrane protein1 (PIP1) aquaporin genes. To determine their role in poplar response to water stress, transgenic Populus tremula × Populus alba plants characterized by the strong down-regulation of multiple isoforms belonging to the PIP1 subfamily were used. Transgenic lines showed that they are more vulnerable to embolism, with 50% percent loss of conductance occurring 0.3 MPa earlier than in wild-type plants, and that they also have a reduced capacity to restore xylem conductance during recovery. Transgenic plants also show symptoms of a reduced capacity to control percent loss of conductance through stomatal conductance in response to drought, because they have a much narrower vulnerability safety margin. Finally, a delay in stomatal conductance recovery during the period of stress relief was observed. The presented results suggest that PIP1 genes are involved in the maintenance of xylem transport system capacity, in the promotion of recovery from stress, and in contribution to a plant's control of stomatal conductance under water stress. PMID:24572173

  20. [Transgenic plants].

    PubMed

    Blum, H E

    2002-12-01

    Advances in molecular genetics and recombinant DNA technology have revolutionized our understanding of the pathogenesis as well as the diagnosis, therapy and prevention of human diseases. Similar developments characterize plant biotechnology with the production of plant derived biomedical as well as health products. Apart from the fundamentals of molecular plant genetics, the production of transgenic plants as well as the clinical relevance, benefits, limitations and potential problems of plant biotechnology will be reviewed in some detail. It is a particular challenge to physicians in an increasingly informed environment to be informed about the new developments in molecular biology and recombinant DNA technology and to have a qualified opinion about their clinical relevance.

  1. 6. GENERAL VIEW EAST FROM ROOFTOP OF POPLAR FOREST TOWARDS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. GENERAL VIEW EAST FROM ROOFTOP OF POPLAR FOREST TOWARDS SUMMER KITCHEN (FOREGROUND) AND DAIRY; CHIMNEY OF SOUTH TENANT HOUSE BARELY VISIBLE THROUGH TREES; EAST PRIVY RARELY VISIBLE OVER EAST MOUND (1987) - Poplar Forest, Summer Kitchen, State Route 661, Forest, Bedford County, VA

  2. 76 FR 28308 - Modification of Class E Airspace; Poplar, MT

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-17

    ...) Global Positioning System (GPS) standard instrument approach procedures at Poplar Municipal Airport... Support Group, Western Service Center, 1601 Lind Avenue SW., Renton, WA 98057; telephone (425) 203-4537... proposed rulemaking to establish additional controlled airspace at Poplar, MT (76 FR 8921)....

  3. Enantioselective Biotransformation of Chiral PCBs in Whole Poplar Plants

    PubMed Central

    Zhai, Guangshu; Hu, Dingfei; Lehmler, Hans-Joachim; Schnoor, Jerald L.

    2011-01-01

    Chiral PCBs have been used as molecular probes of biological metabolic processes due to their special physical, chemical and biological properties. Many animal studies showed the enantioselective biotransformation of chiral PCBs, but it is unclear whether plants can enantioselectively biotransform chiral PCBs. In order to explore the enantioselectivity of chiral PCBs in whole plants, poplars (Populus deltoides × nigra, DN34), a model plant with complete genomic sequence, were hydroponically exposed to 2,2′,3,5′,6-pentachlorobiphenyl (PCB95) and 2,2′,3,3′,6,6′-hexachlorobiphenyl (PCB136) for 20 days. PCB95 and PCB136 were shown to be absorbed, taken-up and translocated in whole poplars, and they were detected in various tissues of whole poplars. However, the enantioselectivity of poplar for PCB95 and PCB136 proved to be quite different. The first eluting enantiomer of PCB95 was enantioselectively removed in whole poplar, especially in the middle and bottom xylem. It was likely enantioselectively metabolized inside poplar tissues, in contrast to racemic mixtures of PCB95 remaining in hydroponic solutions in contact with plant roots of whole and dead poplars. Unlike PCB95, PCB136 remained nearly racemic in most parts of whole poplars after 20 days exposure. These results suggest that PCB136 is more difficult to be enantioslectively biotransformed than PCB95 in whole poplars. This is the first evidence of enantioselectivity of chiral PCBs in whole plants, and suggests that poplars can enantioselectively biotransform at least one chiral PCB. PMID:21329345

  4. Polyphenol oxidase overexpression in transgenic Populus enhances resistance to herbivory by forest tent caterpillar (Malacosoma disstria).

    PubMed

    Wang, Jiehua; Constabel, C Peter

    2004-11-01

    In order to functionally analyze the predicted defensive role of leaf polyphenol oxidase (PPO; EC 1.10.3.1) in Populus, transgenic hybrid aspen (Populus tremula x P. alba) plants overexpressing a hybrid poplar (Populus trichocarpa x P. deltoides) PtdPPO1 gene were constructed. Regenerated transgenic plants showed high PPO enzyme activity, PtdPPO1 mRNA levels and PPO protein accumulation. In leaf disk bioassays, forest tent caterpillar (Malacosoma disstria) larvae feeding on PPO-overexpressing transgenics experienced significantly higher mortality and reduced average weight gain compared to larvae feeding on control leaves. However, this effect was observed only when older egg masses were used and the resulting larvae showed reduced growth and vigor. In choice tests, no effect of PPO overexpression was detected. Although PPO in poplar leaves is latent and requires activation with detergents or trypsin for full enzymatic activity, in caterpillar frass the enzyme was extracted in the fully activated form. This activation correlated with partial proteolytic cleavage, suggesting that PPO latency and activation during digestion could be an adaptive and defense-related feature of poplar PPO.

  5. Transgenic resistance.

    PubMed

    Cillo, Fabrizio; Palukaitis, Peter

    2014-01-01

    Transgenic resistance to plant viruses is an important technology for control of plant virus infection, which has been demonstrated for many model systems, as well as for the most important plant viruses, in terms of the costs of crop losses to disease, and also for many other plant viruses infecting various fruits and vegetables. Different approaches have been used over the last 28 years to confer resistance, to ascertain whether particular genes or RNAs are more efficient at generating resistance, and to take advantage of advances in the biology of RNA interference to generate more efficient and environmentally safer, novel "resistance genes." The approaches used have been based on expression of various viral proteins (mostly capsid protein but also replicase proteins, movement proteins, and to a much lesser extent, other viral proteins), RNAs [sense RNAs (translatable or not), antisense RNAs, satellite RNAs, defective-interfering RNAs, hairpin RNAs, and artificial microRNAs], nonviral genes (nucleases, antiviral inhibitors, and plantibodies), and host-derived resistance genes (dominant resistance genes and recessive resistance genes), and various factors involved in host defense responses. This review examines the above range of approaches used, the viruses that were tested, and the host species that have been examined for resistance, in many cases describing differences in results that were obtained for various systems developed in the last 20 years. We hope this compilation of experiences will aid those who are seeking to use this technology to provide resistance in yet other crops, where nature has not provided such.

  6. Transgenic resistance.

    PubMed

    Cillo, Fabrizio; Palukaitis, Peter

    2014-01-01

    Transgenic resistance to plant viruses is an important technology for control of plant virus infection, which has been demonstrated for many model systems, as well as for the most important plant viruses, in terms of the costs of crop losses to disease, and also for many other plant viruses infecting various fruits and vegetables. Different approaches have been used over the last 28 years to confer resistance, to ascertain whether particular genes or RNAs are more efficient at generating resistance, and to take advantage of advances in the biology of RNA interference to generate more efficient and environmentally safer, novel "resistance genes." The approaches used have been based on expression of various viral proteins (mostly capsid protein but also replicase proteins, movement proteins, and to a much lesser extent, other viral proteins), RNAs [sense RNAs (translatable or not), antisense RNAs, satellite RNAs, defective-interfering RNAs, hairpin RNAs, and artificial microRNAs], nonviral genes (nucleases, antiviral inhibitors, and plantibodies), and host-derived resistance genes (dominant resistance genes and recessive resistance genes), and various factors involved in host defense responses. This review examines the above range of approaches used, the viruses that were tested, and the host species that have been examined for resistance, in many cases describing differences in results that were obtained for various systems developed in the last 20 years. We hope this compilation of experiences will aid those who are seeking to use this technology to provide resistance in yet other crops, where nature has not provided such. PMID:25410101

  7. PdEPF1 regulates water-use efficiency and drought tolerance by modulating stomatal density in poplar.

    PubMed

    Wang, Congpeng; Liu, Sha; Dong, Yan; Zhao, Ying; Geng, Anke; Xia, Xinli; Yin, Weilun

    2016-03-01

    Water deficiency is a critical environmental condition that is seriously reducing global plant production. Improved water-use efficiency (WUE) and drought tolerance are effective strategies to address this problem. In this study, PdEPF1, a member of the EPIDERMAL PATTERNING FACTOR (EPF) family, was isolated from the fast-growing poplar clone NE-19 [Populus nigra × (Populus deltoides × Populus nigra)]. Significantly, higher PdEPF1 levels were detected after induction by dehydration and abscisic acid. To explore the biological functions of PdEPF1, transgenic triploid white poplars (Populus tomentosa 'YiXianCiZhu B385') overexpressing PdEPF1 were constructed. PdEPF1 overexpression resulted in increased water deficit tolerance and greater WUE. We confirmed that the transgenic lines with greater instantaneous WUE had approximately 30% lower transpiration but equivalent CO2 assimilation. Lower transpiration was associated with a 28% reduction in abaxial stomatal density. PdEPF1 overexpression not only strongly enhanced WUE, but also greatly improved drought tolerance, as measured by the leaf relative water content and water potential, under limited water conditions. In addition, the growth of these oxPdEPF1 plants was less adversely affected by reduced water availability than plants with a higher stomatal density, indicating that plants with a low stomatal density may be well suited to grow in water-scarce environments. Taken together, our data suggest that PdEPF1 improves WUE and confers drought tolerance in poplar; thus, it could be used to breed drought-tolerant plants with increased production under conditions of water deficiency. PMID:26228739

  8. Reduced expression of the SHORT-ROOT gene increases the rates of growth and development in hybrid poplar and Arabidopsis.

    PubMed

    Wang, Jiehua; Andersson-Gunnerås, Sara; Gaboreanu, Ioana; Hertzberg, Magnus; Tucker, Matthew R; Zheng, Bo; Leśniewska, Joanna; Mellerowicz, Ewa J; Laux, Thomas; Sandberg, Göran; Jones, Brian

    2011-01-01

    SHORT-ROOT (SHR) is a well characterized regulator of cell division and cell fate determination in the Arabidopsis primary root. However, much less is known about the functions of SHR in the aerial parts of the plant. In this work, we cloned SHR gene from Populus trichocarpa (PtSHR1) as an AtSHR ortholog and down-regulated its expression in hybrid poplar (Populus tremula×P. tremuloides Michx-clone T89) in order to determine its physiological functions in shoot development. Sharing a 90% similarity to AtSHR at amino acid level, PtSHR1 was able to complement the Arabidopsis shr mutant. Down regulation of PtSHR1 led to a strong enhancement of primary (height) and secondary (girth) growth rates in the transgenic poplars. A similar approach in Arabidopsis showed a comparable accelerated growth and development phenotype. Our results suggest that the response to SHR could be dose-dependent and that a partial down-regulation of SHR could lead to enhanced meristem activity and a coordinated acceleration of plant growth in woody species. Therefore, SHR functions in plant growth and development as a regulator of cell division and meristem activity not only in the roots but also in the shoots. Reducing SHR expression in transgenic poplar was shown to lead to significant increases in primary and secondary growth rates. Given the current interest in bioenergy crops, SHR has a broader role as a key regulator of whole plant growth and development and SHR suppression has considerable potential for accelerating biomass accumulation in a variety of species. PMID:22194939

  9. Reduced expression of the SHORT-ROOT gene increases the rates of growth and development in hybrid poplar and Arabidopsis.

    PubMed

    Wang, Jiehua; Andersson-Gunnerås, Sara; Gaboreanu, Ioana; Hertzberg, Magnus; Tucker, Matthew R; Zheng, Bo; Leśniewska, Joanna; Mellerowicz, Ewa J; Laux, Thomas; Sandberg, Göran; Jones, Brian

    2011-01-01

    SHORT-ROOT (SHR) is a well characterized regulator of cell division and cell fate determination in the Arabidopsis primary root. However, much less is known about the functions of SHR in the aerial parts of the plant. In this work, we cloned SHR gene from Populus trichocarpa (PtSHR1) as an AtSHR ortholog and down-regulated its expression in hybrid poplar (Populus tremula×P. tremuloides Michx-clone T89) in order to determine its physiological functions in shoot development. Sharing a 90% similarity to AtSHR at amino acid level, PtSHR1 was able to complement the Arabidopsis shr mutant. Down regulation of PtSHR1 led to a strong enhancement of primary (height) and secondary (girth) growth rates in the transgenic poplars. A similar approach in Arabidopsis showed a comparable accelerated growth and development phenotype. Our results suggest that the response to SHR could be dose-dependent and that a partial down-regulation of SHR could lead to enhanced meristem activity and a coordinated acceleration of plant growth in woody species. Therefore, SHR functions in plant growth and development as a regulator of cell division and meristem activity not only in the roots but also in the shoots. Reducing SHR expression in transgenic poplar was shown to lead to significant increases in primary and secondary growth rates. Given the current interest in bioenergy crops, SHR has a broader role as a key regulator of whole plant growth and development and SHR suppression has considerable potential for accelerating biomass accumulation in a variety of species.

  10. Initial frequency of alleles conferring resistance to Bacillus thuringiensis poplar in a field population of Chrysomela tremulae.

    PubMed Central

    Génissel, Anne; Augustin, Sylvie; Courtin, Claudine; Pilate, Gilles; Lorme, Philippe; Bourguet, Denis

    2003-01-01

    Globally, the estimated total area planted with transgenic plants producing Bacillus thuringiensis (Bt) toxins was 12 million hectares in 2001. The risk of target pests becoming resistant to these toxins has led to the implementation of resistance-management strategies. The efficiency and sustainability of these strategies, including the high-dose plus refuge strategy currently recommended for North American maize, depend on the initial frequency of resistance alleles. In this study, we estimated the initial frequencies of alleles conferring resistance to transgenic Bt poplars producing Cry3A in a natural population of the poplar pest Chrysomela tremulae (Coleoptera: Chrysomelidae). We used the F(2) screen method developed for detecting resistance alleles in natural pest populations. At least three parents of the 270 lines tested were heterozygous for a major Bt resistance allele. We estimated mean resistance-allele frequency for the period 1999-2001 at 0.0037 (95% confidence interval = 0.00045-0.0080) with a detection probability of 90%. These results demonstrate that (i) the F(2) screen method can be used to detect major alleles conferring resistance to Bt-producing plants in insects and (ii) the initial frequency of alleles conferring resistance to Bt toxin can be close to the highest theoretical values that are expected prior to the use of Bt plants if considering fitness costs and typical mutation rates. PMID:12737656

  11. Lignin composition in cambial tissues of poplar.

    PubMed

    Christiernin, M

    2006-01-01

    The cambial tissues of a Populus balsamifera, Balsam poplar clone were studied during a growth season. The Klason and acid-soluble lignin contents were determined as well as the carbohydrate monomer distribution and the protein content. Both the phloem and the xylem sides of the cambial region were examined. The samples were analyzed by thioacidolysis and structures of dimeric products were determined by mass spectrometry after desulphuration. Chemical analysis of samples during the growth season was combined with microscopy of embedded specimens that showed the state of cell differentiation at the time of sampling. In spring and early summer, growth is very rapid and the intention was to collect tissue in which exclusively the middle lamella/primary cell wall had begun to lignify. The Klason lignin, protein content and carbohydrate monomer distribution showed that all the specimens from the cambial tissues sampled during a growth season contained predominantly middle lamella and primary walls; except for the developing xylem sampled in August where the carbohydrate composition showed that secondary walls were present. Thioacidolysis showed that the lignin from the cambial tissues had more condensed structures than the lignin from the reference balsam poplar clone wood. More guaiacyl than syringyl units were detected and mass spectrometry showed that the cambial tissues contained more lignin structures with end-groups than the reference sample. These results suggest that lignification in the cambial layer and early developing xylem may take place predominantly in a bulk fashion during the summer.

  12. A Novel Moderate Constitutive Promoter Derived from Poplar (Populus tomentosa Carrière)

    PubMed Central

    Chen, Zhong; Wang, Jia; Ye, Mei-Xia; Li, Hao; Ji, Le-Xiang; Li, Ying; Cui, Dong-Qing; Liu, Jun-Mei; An, Xin-Min

    2013-01-01

    A novel sequence that functions as a promoter element for moderate constitutive expression of transgenes, designated as the PtMCP promoter, was isolated from the woody perennial Populus tomentosa. The PtMCP promoter was fused to the GUS reporter gene to characterize its expression pattern in different species. In stable Arabidopsis transformants, transcripts of the GUS reporter gene could be detected by RT-PCR in the root, stem, leaf, flower and silique. Further histochemical and fluorometric GUS activity assays demonstrated that the promoter could direct transgene expression in all tissues and organs, including roots, stems, rosette leaves, cauline leaves and flowers of seedlings and maturing plants. Its constitutive expression pattern was similar to that of the CaMV35S promoter, but the level of GUS activity was significantly lower than in CaMV35S promoter::GUS plants. We also characterized the promoter through transient expression in transgenic tobacco and observed similar expression patterns. Histochemical GUS staining and quantitative analysis detected GUS activity in all tissues and organs of tobacco, including roots, stems, leaves, flower buds and flowers, but GUS activity in PtMCP promoter::GUS plants was significantly lower than in CaMV35S promoter::GUS plants. Our results suggested that the PtMCP promoter from poplar is a constitutive promoter with moderate activity and that its function is presumably conserved in different species. Therefore, the PtMCP promoter may provide a practical choice to direct moderate level constitutive expression of transgenes and could be a valuable new tool in plant genetic engineering. PMID:23507754

  13. Plantation forestry under global warming: hybrid poplars with improved thermotolerance provide new insights on the in vivo function of small heat shock protein chaperones.

    PubMed

    Merino, Irene; Contreras, Angela; Jing, Zhong-Ping; Gallardo, Fernando; Cánovas, Francisco M; Gómez, Luis

    2014-02-01

    Climate-driven heat stress is a key factor affecting forest plantation yields. While its effects are expected to worsen during this century, breeding more tolerant genotypes has proven elusive. We report here a substantial and durable increase in the thermotolerance of hybrid poplar (Populus tremula×Populus alba) through overexpression of a major small heat shock protein (sHSP) with convenient features. Experimental evidence was obtained linking protective effects in the transgenic events with the unique chaperone activity of sHSPs. In addition, significant positive correlations were observed between phenotype strength and heterologous sHSP accumulation. The remarkable baseline levels of transgene product (up to 1.8% of total leaf protein) have not been reported in analogous studies with herbaceous species. As judged by protein analyses, such an accumulation is not matched either by endogenous sHSPs in both heat-stressed poplar plants and field-grown adult trees. Quantitative real time-polymerase chain reaction analyses supported these observations and allowed us to identify the poplar members most responsive to heat stress. Interestingly, sHSP overaccumulation was not associated with pleiotropic effects that might decrease yields. The poplar lines developed here also outperformed controls under in vitro and ex vitro culture conditions (callus biomass, shoot production, and ex vitro survival), even in the absence of thermal stress. These results reinforce the feasibility of improving valuable genotypes for plantation forestry, a field where in vitro recalcitrance, long breeding cycles, and other practical factors constrain conventional genetic approaches. They also provide new insights into the biological functions of the least understood family of heat shock protein chaperones.

  14. Neuroanatomy and transgenic technologies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is a short review that introduces recent advances of neuroanatomy and transgenic technologies. The anatomical complexity of the nervous system remains a subject of tremendous fascination among neuroscientists. In order to tackle this extraordinary complexity, powerful transgenic technologies a...

  15. Poplar and its bacterial endophytes: coexistence and harmony

    SciTech Connect

    van der Lelie, D.; Taghavi, S.; Monchy, S.; Schwender, J.; Miller, L.; Ferrieri, R.; Rogers, A.; Zhu, W.; Weyens, N.; Vangronsveld, J.; Newman, L.

    2009-09-01

    Associations between plants and microorganisms are very complex and are the subject of an increasing number of studies. Here, we specifically address the relationship between poplar and its endophytic bacteria. The role and importance of endophytic bacteria in growth and development of their host plants is still underestimated. However, since many endophytes have a beneficial effect on their host, an improved understanding of the interaction between poplar and its endophytic bacteria has the potential to provide major breakthroughs that will improve the productivity of poplar. Endophytic bacteria can improve plant growth and development in a direct or indirect way. Direct plant growth promoting mechanisms may involve nitrogen fixation, production of plant growth regulators such as auxins, cytokinins and gibberellins, and suppression of stress ethylene synthesis by 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. Endophytic bacteria can indirectly benefit the plant by preventing the growth or activity of plant pathogens through competition for space and nutrients, antibiosis, production of hydrolytic enzymes, inhibition of pathogen-produced enzymes or toxins, and through systemic induction of plant defense mechanisms. Examples of applications for custom endophyte-host partnerships include improved productivity and establishment of poplar trees on marginal soils and the phytoremediation of contaminated soils and groundwater. A systems biology approach to understand the synergistic interactions between poplar and its beneficial endophytic bacteria represents an important field of research, which is facilitated by the recent sequencing of the genomes of poplar and several of its endophytic bacteria.

  16. Enzymatic digestion of liquid hot water pretreated hybrid poplar.

    PubMed

    Kim, Youngmi; Mosier, Nathan S; Ladisch, Michael R

    2009-01-01

    Liquid hot (LHW) water pretreatment (LHW) of lignocellulosic material enhances enzymatic conversion of cellulose to glucose by solubilizing hemicellulose fraction of the biomass, while leaving the cellulose more reactive and accessible to cellulase enzymes. Within the range of pretreatment conditions tested in this study, the optimized LHW pretreatment conditions for a 15% (wt/vol) slurry of hybrid poplar were found to be 200(o)C, 10 min, which resulted in the highest fermentable sugar yield with minimal formation of sugar decomposition products during the pretreatment. The LHW pretreatment solubilized 62% of hemicellulose as soluble oligomers. Hot-washing of the pretreated poplar slurry increased the efficiency of hydrolysis by doubling the yield of glucose for a given enzyme dose. The 15% (wt/vol) slurry of hybrid poplar, pretreated at the optimal conditions and hot-washed, resulted in 54% glucose yield by 15 FPU cellulase per gram glucan after 120 h. The hydrolysate contained 56 g/L glucose and 12 g/L xylose. The effect of cellulase loading on the enzymatic digestibility of the pretreated poplar is also reported. Total monomeric sugar yield (glucose and xylose) reached 67% after 72 h of hydrolysis when 40 FPU cellulase per gram glucan were used. An overall mass balance of the poplar-to-ethanol process was established based on the experimentally determined composition and hydrolysis efficiencies of the liquid hot water pretreated poplar.

  17. Continuous steam hydrolysis of tulip poplar

    SciTech Connect

    Fieber, C.; Colcord, A.R.; Faass, S.; Muzzy, J.D.; Roberts, R.S.

    1982-08-01

    To produce ethanol from hardwood it is desirable to fractionate the hardwood in order to produce a relatively pure cellulosic pulp for dilute acid hydrolysis. An experimental investigation of continuous steam hydrolysis of tulip poplar wood chips indicates that over 90% of the lignin present can be extracted by 0.1N sodium hydroxide, resulting in a cellulose pulp containing over 90% hexosan. The study was performed using a Stake Technology, Ltd., continuous digester rated at one oven dry ton per hour of wood chips. The yields of hexosans, hexoses, xylan, xylose, lignin, furfural, acetic acid and methanol were determined as a function of residence time and steam pressure in the digester. The information provides a basis for establishing a material and energy balance for a hardwood to ethanol plant.

  18. Drought response transcriptomes are altered in poplar with reduced tonoplast sucrose transporter expression

    PubMed Central

    Xue, Liang-Jiao; Frost, Christopher J.; Tsai, Chung-Jui; Harding, Scott A.

    2016-01-01

    Transgenic Populus tremula x alba (717-1B4) plants with reduced expression of a tonoplast sucrose efflux transporter, PtaSUT4, exhibit reduced shoot growth compared to wild type (WT) under sustained mild drought. The present study was undertaken to determine whether SUT4-RNAi directly or indirectly altered poplar predisposition and/or response to changes in soil water availability. While sucrose and hexose levels were constitutively elevated in shoot organs, expression responses to drought were most altered in the root tips of SUT4-RNAi plants. Prior to any drought treatment, constitutively elevated transcript levels of abscisic acid biosynthetic genes and bark/vegetative storage proteins suggested altered metabolism in root tips of RNAi plants. Stronger drought-stimulation of stress-inducible genes encoding late-embryogenesis-abundant proteins in transgenic roots was consistent with increased vulnerability to soil drying. Transcript evidence suggested an RNAi effect on intercellular water trafficking by aquaporins in stem xylem during soil drying and recovery. Co-expression network analysis predicted altered integration of abscisic acid sensing/signaling with ethylene and jasmonate sensing/signaling in RNAi compared to WT roots. The overall conclusion is that steepened shoot-root sugar gradient in RNAi plants increased sensitivity of root tips to decreasing soil water availability. PMID:27641356

  19. Drought response transcriptomes are altered in poplar with reduced tonoplast sucrose transporter expression.

    PubMed

    Xue, Liang-Jiao; Frost, Christopher J; Tsai, Chung-Jui; Harding, Scott A

    2016-01-01

    Transgenic Populus tremula x alba (717-1B4) plants with reduced expression of a tonoplast sucrose efflux transporter, PtaSUT4, exhibit reduced shoot growth compared to wild type (WT) under sustained mild drought. The present study was undertaken to determine whether SUT4-RNAi directly or indirectly altered poplar predisposition and/or response to changes in soil water availability. While sucrose and hexose levels were constitutively elevated in shoot organs, expression responses to drought were most altered in the root tips of SUT4-RNAi plants. Prior to any drought treatment, constitutively elevated transcript levels of abscisic acid biosynthetic genes and bark/vegetative storage proteins suggested altered metabolism in root tips of RNAi plants. Stronger drought-stimulation of stress-inducible genes encoding late-embryogenesis-abundant proteins in transgenic roots was consistent with increased vulnerability to soil drying. Transcript evidence suggested an RNAi effect on intercellular water trafficking by aquaporins in stem xylem during soil drying and recovery. Co-expression network analysis predicted altered integration of abscisic acid sensing/signaling with ethylene and jasmonate sensing/signaling in RNAi compared to WT roots. The overall conclusion is that steepened shoot-root sugar gradient in RNAi plants increased sensitivity of root tips to decreasing soil water availability. PMID:27641356

  20. Characterization of antibiosis and antixenosis to the woolly poplar aphid (Hemiptera: Aphididae) in the bark of different poplar genotypes.

    PubMed

    Pointeau, Sophie; Ameline, Arnaud; Sallé, Aurélien; Bankhead-Dronnet, Stéphanie; Lieutier, François

    2013-02-01

    The woolly poplar aphid, Phloeomyzus passerinii (Signoret) (Hemiptera: Aphididae), is a major pest of poplar plantations in the Mediterranean basin and the Near East. Aphids colonize poplar trunks and feed upon the cortical parenchyma. Despite the economic importance of poplar, little is known about the mechanisms involved in poplar resistance to this pest. However, Populus x canadensis Moench genotypes show various levels of resistance to P. passerinii. This study has investigated the type of poplar resistance (antibiosis or antixenosis) by assessing aphid settlement, physiology (survival, development, and reproduction), and stylet penetration behavior (electrical penetration graph) on three P. x canadensis genotypes; '1214' (susceptible), 'Brenta' (resistant), and '145/51' (intermediate). Because settlement was reduced, the highly resistant genotype Brenta exhibited surface antixenosis. In addition, nymphal survival was null on Brenta, and twice less adult aphid initiated a sustained intracellular phase in the cortical parenchyma of that genotype compared with the other two genotypes. Thus, Brenta also showed parenchyma-located antixenosis coupled with antibiosis characteristic. In contrast, P. passerinii had no difficulty to initiate a sustained ingestion in the cortical parenchyma of the intermediate genotype 145/51, but decreased fecundity and lower intrinsic rate of natural increase were clear expressions of antibiosis. PMID:23448064

  1. Molecular Analyses of Transgenic Plants.

    PubMed

    Trijatmiko, Kurniawan Rudi; Arines, Felichi Mae; Oliva, Norman; Slamet-Loedin, Inez Hortense; Kohli, Ajay

    2016-01-01

    One of the major challenges in plant molecular biology is to generate transgenic plants that express transgenes stably over generations. Here, we describe some routine methods to study transgene locus structure and to analyze transgene expression in plants: Southern hybridization using DIG chemiluminescent technology for characterization of transgenic locus, SYBR Green-based real-time RT-PCR to measure transgene transcript level, and protein immunoblot analysis to evaluate accumulation and stability of transgenic protein product in the target tissue. PMID:26614292

  2. GENOME ENABLED MODIFICATION OF POPLAR ROOT DEVELOPMENT FOR INCREASED CARBON SEQUESTRATION

    SciTech Connect

    Busov, Victor

    2013-03-05

    DR5 as a reporter system to study auxin response in Populus Plant Cell Reports 32:453-463 Auxin responsive promoter DR5 reporter system is functional in Populus to monitor auxin response in tissues including leaves, roots, and stems. We described the behavior of the DR5::GUS reporter system in stably transformed Populus plants. We found several similarities with Arabidopsis, including sensitivity to native and synthetic auxins, rapid induction after treatment in a variety of tissues, and maximal responses in root tissues. There were also several important differences from Arabidopsis, including slower time to maximum response and lower induction amplitude. Young leaves and stem sections below the apex showed much higher DR5 activity than did older leaves and stems undergoing secondary growth. DR5 activity was highest in cortex, suggesting high levels of auxin concentration and/or sensitivity in this tissue. Our study shows that the DR5 reporter system is a sensitive and facile system for monitoring auxin responses and distribution at cellular resolution in poplar. The Populus AINTEGUMENTA LIKE 1 homeotic transcription factor PtAIL1 controls the formation of adventitious root primordia. Plant Physiol. 160: 1996-2006 Adventitious rooting is an essential but sometimes rate-limiting step in the clonal multiplication of elite tree germplasm, because the ability to form roots declines rapidly with age in mature adult plant tissues. In spite of the importance of adventitious rooting, the mechanism behind this developmental process remains poorly understood. We have described the transcriptional profiles that are associated with the developmental stages of adventitious root formation in the model tree poplar (Populus trichocarpa). Transcriptome analyses indicate a highly specific temporal induction of the AINTEGUMENTA LIKE1 (PtAIL1) transcription factor of the AP2 family during adventitious root formation. Transgenic poplar samples that overexpressed PtAIL1 were able to

  3. Growing poplars for research with and without mycorrhizas.

    PubMed

    Müller, Anna; Volmer, Katharina; Mishra-Knyrim, Manika; Polle, Andrea

    2013-01-01

    During the last decades the importance of the genus Populus increased because the poplar genome has been sequenced and molecular tools for basic research have become available. Poplar species occur in different habitats and harbor large genetic variation, which can be exploited for economic applications and for increasing our knowledge on the basic molecular mechanisms of the woody life style. Poplars are, therefore, employed to unravel the molecular mechanisms of wood formation, stress tolerance, tree nutrition and interaction with other organisms such as pathogens or mycorrhiza. The basis of these investigations is the reproducible production of homogeneous plant material. In this method paper we describe techniques and growth conditions for the in vitro propagation of different poplar species (Populus × canescens, P. trichocarpa, P. tremula, and P. euphratica) and ectomycorrhizal fungi (Laccaria bicolor, Paxillus involutus) as well as for their co-cultivation for ectomycorrhizal synthesis. Maintenance and plant preparation require different multiplication and rooting media. Growth systems to cultivate poplars under axenic conditions in agar and sand cultures with and without mycorrhizal fungi are described. Transfer of the plants from in vitro to in situ conditions is critical and hardening is important to prevent high mortality. Growth and vitality of the trees in vitro and outdoors with and without ectomycorrhizas are reported.

  4. Growing poplars for research with and without mycorrhizas

    PubMed Central

    Müller, Anna; Volmer, Katharina; Mishra-Knyrim, Manika; Polle, Andrea

    2013-01-01

    During the last decades the importance of the genus Populus increased because the poplar genome has been sequenced and molecular tools for basic research have become available. Poplar species occur in different habitats and harbor large genetic variation, which can be exploited for economic applications and for increasing our knowledge on the basic molecular mechanisms of the woody life style. Poplars are, therefore, employed to unravel the molecular mechanisms of wood formation, stress tolerance, tree nutrition and interaction with other organisms such as pathogens or mycorrhiza. The basis of these investigations is the reproducible production of homogeneous plant material. In this method paper we describe techniques and growth conditions for the in vitro propagation of different poplar species (Populus × canescens, P. trichocarpa, P. tremula, and P. euphratica) and ectomycorrhizal fungi (Laccaria bicolor, Paxillus involutus) as well as for their co-cultivation for ectomycorrhizal synthesis. Maintenance and plant preparation require different multiplication and rooting media. Growth systems to cultivate poplars under axenic conditions in agar and sand cultures with and without mycorrhizal fungi are described. Transfer of the plants from in vitro to in situ conditions is critical and hardening is important to prevent high mortality. Growth and vitality of the trees in vitro and outdoors with and without ectomycorrhizas are reported. PMID:23986772

  5. Direct diet quantification indicates low intakes of (n-3) fatty acids in children 4 to 8 years old.

    PubMed

    Madden, Sarah M M; Garrioch, Colin F; Holub, Bruce J

    2009-03-01

    Estimates of essential fatty acid intakes, including (n-3) PUFA, are available in pediatric populations based on limited indirect approaches. Furthermore, recommended intakes for short- and long-chain (LC) (n-3) PUFA have emerged for this population. This study provides direct quantification of fatty acid intakes in children aged 4-8 y. Identical portions of all food and natural health products consumed over 3 d were collected. Duplicate samples were analyzed for energy, macronutrients, and fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) by high performance capillary GLC. The results for 41 children [25 females, 16 males; 5.8 +/- 0.2 y (mean age +/- SEM)] showed daily energy intakes of 5879 +/- 211 kJ (mean +/- SEM) and (n-3) PUFA intakes in mg/d as follows: ALA, 1161 +/- 108; EPA, 38.4 +/- 9.3; DPA, 26.3 +/- 3.9; and DHA, 54.1 +/- 11.4. Based on the Dietary Reference Intakes from the Institute of Medicine, 61% of the children met the adequate intake for ALA and 22% met the suggested adequate intake for DHA+EPA (10% of the adequate intake for ALA). These intakes were also compared with the recent Australia/New Zealand recommendations for children, where only 51% met the recommended intake for EPA+DPA+DHA. These results demonstrate a moderate shortfall in ALA intake in Canadian children and a nutrient gap for the LC (n-3) PUFA, including DHA, when comparing intakes for this population to suggested and recommended intakes.

  6. Executive Function Skills of 6 to 8 Year Olds: Brain and Behavioral Evidence and Implications for School Achievement

    PubMed Central

    Molfese, Victoria J.; Molfese, Peter J.; Molfese, Dennis L.; Rudasill, Kathleen M.; Armstrong, Natalie; Starkey, Gillian

    2010-01-01

    Academic and social success in school has been linked to children’s self-regulation. This study investigated the assessment of the executive function (EF) component of self-regulation using a low-cost, easily administered measure to determine whether scores obtained from the behavioral task would agree with those obtained using a laboratory-based neuropsychological measure of EF skills. The sample included 74 children (37 females; M = 86.2 months) who participated in two assessments of working memory and inhibitory control: Knock-Tap (NEPSY: Korkman, Kirk, and Kemp, 1998), and participation in event-related potential (ERP) testing that included the Directional Stroop Test (Davidson, Cruess, Diamond, O’Craven, & Savoy, 1999). Three main findings emerged. First, children grouped as high versus low performing on the NEPSY Knock-Tap Task were found to performed differently on the more difficult conditions of the DST (the Incongruent and Mixed Conditions), suggesting that the Knock-Tap Task as a low-cost and easy to administer assessment of EF skills may be one way for teachers to identify students with poor inhibitory control skills. Second, children’s performance on the DST was strongly related to their ERP responses, adding to evidence that differences in behavioral performance on the DST as a measure of EF skills reflect corresponding differences in brain processing. Finally, differences in brain processing on the DST task also were found when the children were grouped based on Knock-Tap performance. Simple screening procedures can enable teachers to identify children whose distractibility, inattentiveness, or poor attention spans may interfere with classroom learning. PMID:20798857

  7. Executive Function Skills of 6-8 Year Olds: Brain and Behavioral Evidence and Implications for School Achievement

    ERIC Educational Resources Information Center

    Molfese, Victoria J.; Molfese, Peter J.; Molfese, Dennis L.; Rudasill, Kathleen Moritz; Armstrong, Natalie; Starkey, Gillian

    2010-01-01

    Academic and social success in school has been linked to children's self-regulation. This study investigated the assessment of the executive function (EF) component of self-regulation using a low-cost, easily administered measure to determine whether scores obtained from the behavioral task would agree with those obtained using a laboratory-based…

  8. Determination of tissue equivalent materials of a physical 8-year-old phantom for use in computed tomography

    NASA Astrophysics Data System (ADS)

    Akhlaghi, Parisa; Miri Hakimabad, Hashem; Rafat Motavalli, Laleh

    2015-07-01

    This paper reports on the methodology applied to select suitable tissue equivalent materials of an 8-year phantom for use in computed tomography (CT) examinations. To find the appropriate tissue substitutes, first physical properties (physical density, electronic density, effective atomic number, mass attenuation coefficient and CT number) of different materials were studied. Results showed that, the physical properties of water and polyurethane (as soft tissue), B-100 and polyvinyl chloride (PVC) (as bone) and polyurethane foam (as lung) agree more with those of original tissues. Then in the next step, the absorbed doses in the location of 25 thermoluminescent dosimeters (TLDs) as well as dose distribution in one slice of phantom were calculated for original and these proposed materials by Monte Carlo simulation at different tube voltages. The comparisons suggested that at tube voltages of 80 and 100 kVp using B-100 as bone, water as soft tissue and polyurethane foam as lung is suitable for dosimetric study in pediatric CT examinations. In addition, it was concluded that by considering just the mass attenuation coefficient of different materials, the appropriate tissue equivalent substitutes in each desired X-ray energy range could be found.

  9. The Art of Teaching Children the Arts: Music, Dance and Poetry with Children Aged 2-8 Years Old

    ERIC Educational Resources Information Center

    Samuelsson, Ingrid Pramling; Carlsson, Maj Asplund; Olsson, Bengt; Pramling, Niklas; Wallerstedt, Cecilia

    2009-01-01

    In this article, the theoretical framework of developmental pedagogy is presented as a tool in studying and developing children's knowing within the arts. The domains of art focused on are music, poetry and dance/aesthetic movement. Through empirical examples from a large-scale research project, we illustrate the tools of developmental pedagogy…

  10. Neuropsychological Measures of Attention and Impulse Control among 8-Year-Old Children Exposed Prenatally to Organochlorines

    PubMed Central

    Thurston, Sally W.; Bellinger, David C.; Altshul, Larisa M.; Korrick, Susan A.

    2012-01-01

    Background: We previously reported associations between organochlorines and behaviors related to attention deficit hyperactivity disorder among boys and girls at 8 years of age using a teacher’s rating scale for a birth cohort in New Bedford, Massachusetts (USA). Objectives: Our goal was to corroborate these findings using neuropsychological measures of inattentive and impulsive behaviors. Methods: We investigated the association between cord serum polychlorinated biphenyls (PCBs) and p,p´-dichlorodiphenyl dichloroethylene (p,p´-DDE) and attention and impulse control using a Continuous Performance Test (CPT) and components of the Wechsler Intelligence Scale for Children, 3rd edition (WISC-III). Participants came from a prospective cohort of children born during 1993–1998 to mothers residing near a PCB-contaminated harbor in New Bedford. Median (range) cord serum levels for the sum of four prevalent PCBs [congeners 118, 138, 153, and 180 (ΣPCB4)] and p,p´-DDE were 0.19 (0.01–2.59) and 0.31 (0–14.93) ng/g serum, respectively. Results: We detected associations between PCBs and neuropsychological deficits for 578 and 584 children with CPT and WISC-III measures, respectively, but only among boys. For example, boys with higher exposure to ΣPCB4 had a higher rate of CPT errors of omission [rate ratio for the exposure interquartile range (IQR) = 1.12; 95% confidence interval (CI): 0.98, 1.27] and slower WISC-III Processing Speed (change in score for the IQR = –2.0; 95% CI: –3.5, –0.4). Weaker associations were found for p,p´-DDE. For girls, associations were in the opposite direction for the CPT and null for the WISC-III. Conclusions: These results support an association between organochlorines (mainly PCBs) and neuropsychological measures of attention among boys only. Sex-specific effects should be considered in studies of organochlorines and neurodevelopment. PMID:22357172

  11. Serum fatty acids in 8-year-old Finnish boys: correlations with qualitative dietary data and other serum lipids.

    PubMed

    Nikkari, T; Räsänen, L; Viikari, J; Akerblom, H K; Vuori, I; Pyörälä, K; Uhari, M; Dahl, M; Lähde, P L; Pesonen, E; Suoninen, P

    1983-05-01

    To survey risk factors in coronary heart disease in Finnish children, fasting serum specimens from 244 healthy 8-yr-old boys were analyzed for the fatty acid composition of cholesterol esters (CE), triglycerides (TG), free fatty acids (FFA), and phospholipids (PL). A qualitative dietary survey was made by asking parents to answer a questionnaire including, among others, a question on the kind of fat usually used on bread by the child. The mean percentages of linoleate (18:2) in serum cholesterol esters, triglycerides, free fatty acids, and phospholipids were 53.1, 13.5, 11.5, and 22.7%, respectively, which represent an international average. The quality of dietary fat had a clear influence on serum fatty acids, eg, the content of 18:2 in CE was 56.8 +/- 3.6% in boys using soft vegetable margarine and 50.5 +/- 3.6% in those using butter. The former had also a marginally lower serum total cholesterol (4.87 +/- 0.86 mmol/l) than the latter (5.08 +/- 0.80 mmol/l). Serum total cholesterol showed significant negative correlations with the percentage of 18:2 in all four lipid fractions, the highest r values being with PL-18:2 (-0.41) and CE-18:2 (-0.24). Accordingly, serum cholesterol was lower in the highest CE-18:2 quartile (4.67 +/- 0.76 mmol/l) compared with the lowest (5.30 +/- 0.70 mmol/l; p less than 0.001). The results indicate that when serum fatty acids are used as indicators of the quality of dietary fat, a negative association between polyunsaturated fat and serum cholesterol may be demonstrable even within a free-living population.

  12. Comorbidity and correlates of disruptive mood dysregulation disorder in 6-8-year-old children with ADHD.

    PubMed

    Mulraney, Melissa; Schilpzand, Elizabeth J; Hazell, Philip; Nicholson, Jan M; Anderson, Vicki; Efron, Daryl; Silk, Timothy J; Sciberras, Emma

    2016-03-01

    This study aimed to characterize the nature and impact of disruptive mood dysregulation disorder (DMDD) in children with attention-deficit/hyperactivity disorder (ADHD) including its co-occurrence with other comorbidities and its independent influence on daily functioning. Children with ADHD (6-8 years) were recruited through 43 Melbourne schools, using a 2-stage screening (parent and teacher Conners 3 ADHD index) and case-confirmation (Diagnostic Interview Schedule for Children, Version IV; [DISC-IV]) procedure. Proxy DMDD diagnosis was confirmed via items from the oppositional defiant disorder (ODD) and major depressive disorder modules of the DISC-IV. Outcome domains included comorbid mental health disorders, academic functioning, social functioning, child and family quality of life, parent mental health, and parenting behaviors. Unadjusted and adjusted linear and logistic regression were used to compare children with comorbid ADHD and DMDD and children with ADHD without DMDD. Thirty-nine out of 179 children (21.8 %) with ADHD had comorbid DMDD. Children with ADHD and DMDD had a high prevalence of ODD (89.7 %) and any anxiety disorder (41.0 %). Children with ADHD and DMDD had poorer self-control and elevated bullying behaviors than children with ADHD without DMDD. Children with ADHD and DMDD were similar to children with ADHD in the other domains measured when taking into account other comorbidities including ODD. One in five children with ADHD in their second year of formal schooling met criteria for DMDD. There was a very high diagnostic overlap with ODD; however, the use of a proxy DMDD diagnosis containing items from the ODD module of the DISC-IV may have artificially inflated the comorbidity rates. DMDD added to the burden of ADHD particularly in the area of social functioning. PMID:26122202

  13. Training 8-Year-Old French Immersion Students in Metalinguistic Analysis: An Innovation in Form-Focused Pedagogy

    ERIC Educational Resources Information Center

    Bouffard, Laura Annie; Sarkar, Mela

    2008-01-01

    Most research on language awareness in a second language (L2) has been carried out with adult learners. This research presents data showing that pedagogical techniques can be devised enabling children as young as 8 to develop metalinguistic awareness of their emerging L2 system. Building on existing work by Canadian researchers, this…

  14. Manually segmented template library for 8-year-old pediatric brain MRI data with 16 subcortical structures

    PubMed Central

    Garg, Amanmeet; Wong, Darren; Popuri, Karteek; Poskitt, Kenneth J.; Fitzpatrick, Kevin; Bjornson, Bruce; Grunau, Ruth E.; Beg, Mirza Faisal

    2014-01-01

    Abstract. Manual segmentation of anatomy in brain MRI data taken to be the closest to the “gold standard” in quality is often used in automated registration-based segmentation paradigms for transfer of template labels onto the unlabeled MRI images. This study presents a library of template data with 16 subcortical structures in the central brain area which were manually labeled for MRI data from 22 children (8 male, mean age=8±0.6  years). The lateral ventricle, thalamus, caudate, putamen, hippocampus, cerebellum, third vevntricle, fourth ventricle, brainstem, and corpuscallosum were segmented by two expert raters. Cross-validation experiments with randomized template subset selection were conducted to test for their ability to accurately segment MRI data under an automated segmentation pipeline. A high value of the dice similarity coefficient (0.86±0.06, min=0.74, max=0.96) and small Hausdorff distance (3.33±4.24, min=0.63, max=25.24) of the automated segmentation against the manual labels was obtained on this template library data. Additionally, comparison with segmentation obtained from adult templates showed significant improvement in accuracy with the use of an age-matched library in this cohort. A manually delineated pediatric template library such as the one described here could provide a useful benchmark for testing segmentation algorithms. PMID:26158067

  15. Manually segmented template library for 8-year-old pediatric brain MRI data with 16 subcortical structures.

    PubMed

    Garg, Amanmeet; Wong, Darren; Popuri, Karteek; Poskitt, Kenneth J; Fitzpatrick, Kevin; Bjornson, Bruce; Grunau, Ruth E; Beg, Mirza Faisal

    2014-10-01

    Manual segmentation of anatomy in brain MRI data taken to be the closest to the "gold standard" in quality is often used in automated registration-based segmentation paradigms for transfer of template labels onto the unlabeled MRI images. This study presents a library of template data with 16 subcortical structures in the central brain area which were manually labeled for MRI data from 22 children (8 male, [Formula: see text]). The lateral ventricle, thalamus, caudate, putamen, hippocampus, cerebellum, third vevntricle, fourth ventricle, brainstem, and corpuscallosum were segmented by two expert raters. Cross-validation experiments with randomized template subset selection were conducted to test for their ability to accurately segment MRI data under an automated segmentation pipeline. A high value of the dice similarity coefficient ([Formula: see text], [Formula: see text], [Formula: see text]) and small Hausdorff distance ([Formula: see text], [Formula: see text], [Formula: see text]) of the automated segmentation against the manual labels was obtained on this template library data. Additionally, comparison with segmentation obtained from adult templates showed significant improvement in accuracy with the use of an age-matched library in this cohort. A manually delineated pediatric template library such as the one described here could provide a useful benchmark for testing segmentation algorithms.

  16. The Role of Orbitofrontal Cortex in Processing Empathy Stories in 4- to 8-Year-Old Children

    PubMed Central

    Brink, Tila Tabea; Urton, Karolina; Held, Dada; Kirilina, Evgeniya; Hofmann, Markus J.; Klann-Delius, Gisela; Jacobs, Arthur M.; Kuchinke, Lars

    2010-01-01

    This study investigates the neuronal correlates of empathic processing in children aged 4–8 years, an age range discussed to be crucial for the development of empathy. Empathy, defined as the ability to understand and share another person's inner life, consists of two components: affective (emotion-sharing) and cognitive empathy (Theory of Mind). We examined the hemodynamic responses of preschool and school children (N = 48), while they processed verbal (auditory) and non-verbal (cartoons) empathy stories in a passive following paradigm, using functional Near-Infrared Spectroscopy. To control for the two types of empathy, children were presented blocks of stories eliciting either affective or cognitive empathy, or neutral scenes which relied on the understanding of physical causalities. By contrasting the activations of the younger and older children, we expected to observe developmental changes in brain activations when children process stories eliciting empathy in either stimulus modality toward a greater involvement of anterior frontal brain regions. Our results indicate that children's processing of stories eliciting affective and cognitive empathy is associated with medial and bilateral orbitofrontal cortex (OFC) activation. In contrast to what is known from studies using adult participants, no additional recruitment of posterior brain regions was observed, often associated with the processing of stories eliciting empathy. Developmental changes were found only for stories eliciting affective empathy with increased activation, in older children, in medial OFC, left inferior frontal gyrus, and the left dorsolateral prefrontal cortex. Activations for the two modalities differ only little, with non-verbal presentation of the stimuli having a greater impact on empathy processing in children, showing more similarities to adult processing than the verbal one. This might be caused by the fact that non-verbal processing develops earlier in life and is more familiar. PMID:21687450

  17. Narrative Skills, Cognitive Profiles and Neuropsychiatric Disorders in 7-8-Year-Old Children with Late Developing Language

    ERIC Educational Resources Information Center

    Miniscalco, Carmela; Hagberg, Bibbi; Kadesjo, Bjorn; Westerlund, Monica; Gillberg, Christopher

    2007-01-01

    Background: A community-representative sample of screened and clinically examined children with language delay at 2.5 years of age was followed up at school age when their language development was again examined and the occurrence of neuropsychiatric/neurodevelopmental disorder (attention deficit/hyperactivity disorder (ADHD) and/or autism…

  18. Endogenous Cushing's Syndrome with Precocious Puberty in an 8-Year-Old Boy due to a Large Unilateral Adrenal Adenoma

    PubMed Central

    Hossain, Muhammad Rajib; Alam, Md. Mashiul; Nabi, Junaid; Kibria, Mahzabin

    2013-01-01

    Adrenocortical tumors (ACTs) causing Cushing's syndrome are extremely rare in children and adolescents. Bilateral macronodular adrenocortical disease which is a component of the McCune-Albright syndrome is the most common cause of endogenous Cushing's syndrome. We report the case of a boy with Cushing's syndrome who presented with obesity and growth retardation. The child was hypertensive. The biochemical evaluation revealed that his serum cortisol levels were 25.80 μg/dL, with a concomitant plasma ACTH level of 10.0 pg/mL and nonsuppressed serum cortisol on high-dose dexamethasone suppression test (HDDST) to be 20.38 μg/dL. Computed tomography of the abdomen demonstrated a 8 × 6 × 5 cm left adrenal mass with internal calcifications. Following preoperative stabilization, laparotomy was carried out which revealed a lobulated left adrenal mass with intact capsule weighing 120 grams. Histopathological examination revealed a benign cortical neoplastic lesion, suggestive of adrenal adenoma; composed of large polygonal cells with centrally placed nuclei and prominent nucleoli without capsular and vascular invasion. On the seventh postoperative day, cortisol levels were within normal range indicating biochemical remission of Cushing's syndrome. On followup after three months, the patient showed significant clinical improvement and had lost moderate amount of weight and adrenal imaging was found to be normal. PMID:23533838

  19. Anaphylactoid Purpura Manifested after Acute Gastroenteritis with Severe Dehydration in an 8-Year-Old Male Child: A Case Report.

    PubMed

    Thakkar, Umang G; Vanikar, Aruna V; Trivedi, Hargovind L

    2015-12-01

    Anaphylactoid purpura, also known as Henoch-Schönleinpurpura (HSP), is an IgA-mediated vasculitis that tends to be a benign disease of childhood. Up to 50% of cases are preceded by an upper tract respiratory infection caused by group-A beta-hemolytic streptococcus and present with the common tetrad of abdominal pain, arthritis, purpuric rash, and renal involvement. The majority of patients recover completely. Here we document a rare case of anaphylactoid purpura which manifested with skin lesions in the form of palpable purpura following about of acute gastroenteritis with severe dehydration; it was treated with a short regimen of steroid therapy, which resulted in the complete remission of the disease. We conclude that prompt diagnosis and multidisciplinary intervention will lead to appropriate management-consisting of the installation of early short-course steroid therapy and thus, prevent further complications and the recurrence of the disease. PMID:26602584

  20. The ectomycorrhizal fungus Laccaria bicolor stimulates lateral root formation in poplar and Arabidopsis through auxin transport and signaling.

    PubMed

    Felten, Judith; Kohler, Annegret; Morin, Emmanuelle; Bhalerao, Rishikesh P; Palme, Klaus; Martin, Francis; Ditengou, Franck A; Legué, Valérie

    2009-12-01

    The early phase of the interaction between tree roots and ectomycorrhizal fungi, prior to symbiosis establishment, is accompanied by a stimulation of lateral root (LR) development. We aimed to identify gene networks that regulate LR development during the early signal exchanges between poplar (Populus tremula x Populus alba) and the ectomycorrhizal fungus Laccaria bicolor with a focus on auxin transport and signaling pathways. Our data demonstrated that increased LR development in poplar and Arabidopsis (Arabidopsis thaliana) interacting with L. bicolor is not dependent on the ability of the plant to form ectomycorrhizae. LR stimulation paralleled an increase in auxin accumulation at root apices. Blocking plant polar auxin transport with 1-naphthylphthalamic acid inhibited LR development and auxin accumulation. An oligoarray-based transcript profile of poplar roots exposed to molecules released by L. bicolor revealed the differential expression of 2,945 genes, including several components of polar auxin transport (PtaPIN and PtaAUX genes), auxin conjugation (PtaGH3 genes), and auxin signaling (PtaIAA genes). Transcripts of PtaPIN9, the homolog of Arabidopsis AtPIN2, and several PtaIAAs accumulated specifically during the early interaction phase. Expression of these rapidly induced genes was repressed by 1-naphthylphthalamic acid. Accordingly, LR stimulation upon contact with L. bicolor in Arabidopsis transgenic plants defective in homologs of these genes was decreased or absent. Furthermore, in Arabidopsis pin2, the root apical auxin increase during contact with the fungus was modified. We propose a model in which fungus-induced auxin accumulation at the root apex stimulates LR formation through a mechanism involving PtaPIN9-dependent auxin redistribution together with PtaIAA-based auxin signaling.

  1. Down-regulation of gibberellic acid in poplar has negligible effects on host-plant suitability and insect pest response

    SciTech Connect

    Buhl, Christine; Strauss, Steven H.; Lindroth, Richard L.

    2015-01-06

    Abstract Endogenous levels and signaling of gibberellin plant hormones such as gibberellic acid (GA) have been genetically down-regulated to create semi-dwarf varieties of poplar. The potential benefits of semi-dwarf stature include reduced risk of wind damage, improved stress tolerance, and improved wood quality. Despite these benefits, modification of growth traits may have consequences for non-target traits that confer defense against insect herbivores. According to the growth-differentiation balance hypothesis, reductions in growth may shift allocation of carbon from growth to chemical resistance traits, thereby altering plant defense. To date, host-plant suitability and pest response have not been comprehensively evaluated in GA down-regulated plants. We quantified chemical resistance and nitrogen (an index of protein) in GA down-regulated and wild-type poplar (Populus alba × P. tremula) genotypes. We also evaluated performance of both generalist (Lymantria dispar) and specialist (Chrysomela scripta) insect pests reared on these genotypes. Our evaluation of resistance traits in four GA down-regulated genotypes revealed increased phenolic glycosides in one modified genotype and reduced lignin in two modified genotypes relative to the non-transgenic wild type. Nitrogen levels did not vary significantly among the experimental genotypes. Generalists reared on the four GA down-regulated genotypes exhibited reduced performance on only one modified genotype relative to the wild type. Specialists, however, performed similarly across all genotypes. Results from this study indicate that although some non-target traits varied among GA down-regulated genotypes, the differences in poplar pest susceptibility were modest and highly genotype-specific.

  2. Down-regulation of gibberellic acid in poplar has negligible effects on host-plant suitability and insect pest response

    DOE PAGESBeta

    Buhl, Christine; Strauss, Steven H.; Lindroth, Richard L.

    2015-01-06

    Abstract Endogenous levels and signaling of gibberellin plant hormones such as gibberellic acid (GA) have been genetically down-regulated to create semi-dwarf varieties of poplar. The potential benefits of semi-dwarf stature include reduced risk of wind damage, improved stress tolerance, and improved wood quality. Despite these benefits, modification of growth traits may have consequences for non-target traits that confer defense against insect herbivores. According to the growth-differentiation balance hypothesis, reductions in growth may shift allocation of carbon from growth to chemical resistance traits, thereby altering plant defense. To date, host-plant suitability and pest response have not been comprehensively evaluated in GAmore » down-regulated plants. We quantified chemical resistance and nitrogen (an index of protein) in GA down-regulated and wild-type poplar (Populus alba × P. tremula) genotypes. We also evaluated performance of both generalist (Lymantria dispar) and specialist (Chrysomela scripta) insect pests reared on these genotypes. Our evaluation of resistance traits in four GA down-regulated genotypes revealed increased phenolic glycosides in one modified genotype and reduced lignin in two modified genotypes relative to the non-transgenic wild type. Nitrogen levels did not vary significantly among the experimental genotypes. Generalists reared on the four GA down-regulated genotypes exhibited reduced performance on only one modified genotype relative to the wild type. Specialists, however, performed similarly across all genotypes. Results from this study indicate that although some non-target traits varied among GA down-regulated genotypes, the differences in poplar pest susceptibility were modest and highly genotype-specific.« less

  3. The Ectomycorrhizal Fungus Laccaria bicolor Stimulates Lateral Root Formation in Poplar and Arabidopsis through Auxin Transport and Signaling1[W

    PubMed Central

    Felten, Judith; Kohler, Annegret; Morin, Emmanuelle; Bhalerao, Rishikesh P.; Palme, Klaus; Martin, Francis; Ditengou, Franck A.; Legué, Valérie

    2009-01-01

    The early phase of the interaction between tree roots and ectomycorrhizal fungi, prior to symbiosis establishment, is accompanied by a stimulation of lateral root (LR) development. We aimed to identify gene networks that regulate LR development during the early signal exchanges between poplar (Populus tremula × Populus alba) and the ectomycorrhizal fungus Laccaria bicolor with a focus on auxin transport and signaling pathways. Our data demonstrated that increased LR development in poplar and Arabidopsis (Arabidopsis thaliana) interacting with L. bicolor is not dependent on the ability of the plant to form ectomycorrhizae. LR stimulation paralleled an increase in auxin accumulation at root apices. Blocking plant polar auxin transport with 1-naphthylphthalamic acid inhibited LR development and auxin accumulation. An oligoarray-based transcript profile of poplar roots exposed to molecules released by L. bicolor revealed the differential expression of 2,945 genes, including several components of polar auxin transport (PtaPIN and PtaAUX genes), auxin conjugation (PtaGH3 genes), and auxin signaling (PtaIAA genes). Transcripts of PtaPIN9, the homolog of Arabidopsis AtPIN2, and several PtaIAAs accumulated specifically during the early interaction phase. Expression of these rapidly induced genes was repressed by 1-naphthylphthalamic acid. Accordingly, LR stimulation upon contact with L. bicolor in Arabidopsis transgenic plants defective in homologs of these genes was decreased or absent. Furthermore, in Arabidopsis pin2, the root apical auxin increase during contact with the fungus was modified. We propose a model in which fungus-induced auxin accumulation at the root apex stimulates LR formation through a mechanism involving PtaPIN9-dependent auxin redistribution together with PtaIAA-based auxin signaling. PMID:19854859

  4. Proteomics of nitrogen remobilization in poplar bark.

    PubMed

    Islam, Nazrul; Li, Gen; Garrett, Wesley M; Lin, Rongshuang; Sriram, Ganesh; Cooper, Bret; Coleman, Gary D

    2015-02-01

    Seasonal nitrogen (N) cycling in temperate deciduous trees involves the accumulation of bark storage proteins (BSPs) in phloem parenchyma and xylem ray cells. BSPs are anabolized using recycled N during autumn leaf senescence and later become a source of N during spring shoot growth as they are catabolized. Little is known about the catabolic processes involved in remobilization and reutilization of N from BSPs in trees. In this study, we used multidimensional protein identification technology (MudPIT) and spectral counting to identify protein changes that occur in the bark during BSP catabolism. A total of 4,178 proteins were identified from bark prior to and during BSP catabolism. The majority (62%) of the proteins were found during BSP catabolism, indicating extensive remodeling of the proteome during renewed shoot growth and N remobilization. Among these proteins were 30 proteases, the relative abundances of which increased during BSP catabolism. These proteases spanned a range of families including members of the papain-like cysteine proteases, serine carboxypeptidases, and aspartyl proteases. These data identify, for the first time, candidate proteases that could potentially provide hydrolase activity required for N remobilization from BSPs and provide the foundation for research to advance our knowledge of poplar N cycling.

  5. Proteome Analysis of Poplar Seed Vigor

    PubMed Central

    Zhang, Hong; Wang, Wei-Qing; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

    2015-01-01

    Seed vigor is a complex property that determines the seed’s potential for rapid uniform emergence and subsequent growth. However, the mechanism for change in seed vigor is poorly understood. The seeds of poplar (Populus × Canadensis Moench), which are short-lived, were stored at 30°C and 75±5% relative humidity for different periods of time (0–90 days) to obtain different vigor seeds (from 95 to 0% germination). With decreasing seed vigor, the temperature range of seed germination became narrower; the respiration rate of the seeds decreased markedly, while the relative electrolyte leakage increased markedly, both levelling off after 45 days. A total of 81 protein spots showed a significant change in abundance (≥ 1.5-fold, P < 0.05) when comparing the proteomes among seeds with different vigor. Of the identified 65 proteins, most belonged to the groups involved in metabolism (23%), protein synthesis and destination (22%), energy (18%), cell defense and rescue (17%), and storage protein (15%). These proteins accounted for 95% of all the identified proteins. During seed aging, 53 and 6 identified proteins consistently increased and decreased in abundance, respectively, and they were associated with metabolism (22%), protein synthesis and destination (22%), energy (19%), cell defense and rescue (19%), storage proteins (15%), and cell growth and structure (3%). These data show that the decrease in seed vigor (aging) is an energy-dependent process, which requires protein synthesis and degradation as well as cellular defense and rescue. PMID:26172265

  6. Fitness dynamics within a poplar hybrid zone: II. Impact of exotic sex on native poplars in an urban jungle.

    PubMed

    Roe, Amanda D; MacQuarrie, Chris Jk; Gros-Louis, Marie-Claude; Simpson, J Dale; Lamarche, Josyanne; Beardmore, Tannis; Thompson, Stacey L; Tanguay, Philippe; Isabel, Nathalie

    2014-05-01

    Trees bearing novel or exotic gene components are poised to contribute to the bioeconomy for a variety of purposes such as bioenergy production, phytoremediation, and carbon sequestration within the forestry sector, but sustainable release of trees with novel traits in large-scale plantations requires the quantification of risks posed to native tree populations. Over the last century, exotic hybrid poplars produced through artificial crosses were planted throughout eastern Canada as ornamentals or windbreaks and these exotics provide a proxy by which to examine the fitness of exotic poplar traits within the natural environment to assess risk of exotic gene escape, establishment, and spread into native gene pools. We assessed postzygotic fitness traits of native and exotic poplars within a naturally regenerated stand in eastern Canada (Quebec City, QC). Pure natives (P. balsamifera and P. deltoides spp. deltoides), native hybrids (P. deltoides × P. balsamifera), and exotic hybrids (trees bearing Populus nigra and P. maximowiczii genetic components) were screened for reproductive biomass, yield, seed germination, and fungal disease susceptibility. Exotic hybrids expressed fitness traits intermediate to pure species and were not significantly different from native hybrids. They formed fully viable seed and backcrossed predominantly with P. balsamifera. These data show that exotic hybrids were not unfit and were capable of establishing and competing within the native stand. Future research will seek to examine the impact of exotic gene regions on associated biotic communities to fully quantify the risk exotic poplars pose to native poplar forests.

  7. Fitness dynamics within a poplar hybrid zone: II. Impact of exotic sex on native poplars in an urban jungle

    PubMed Central

    Roe, Amanda D; MacQuarrie, Chris JK; Gros-Louis, Marie-Claude; Simpson, J Dale; Lamarche, Josyanne; Beardmore, Tannis; Thompson, Stacey L; Tanguay, Philippe; Isabel, Nathalie

    2014-01-01

    Trees bearing novel or exotic gene components are poised to contribute to the bioeconomy for a variety of purposes such as bioenergy production, phytoremediation, and carbon sequestration within the forestry sector, but sustainable release of trees with novel traits in large-scale plantations requires the quantification of risks posed to native tree populations. Over the last century, exotic hybrid poplars produced through artificial crosses were planted throughout eastern Canada as ornamentals or windbreaks and these exotics provide a proxy by which to examine the fitness of exotic poplar traits within the natural environment to assess risk of exotic gene escape, establishment, and spread into native gene pools. We assessed postzygotic fitness traits of native and exotic poplars within a naturally regenerated stand in eastern Canada (Quebec City, QC). Pure natives (P. balsamifera and P. deltoides spp. deltoides), native hybrids (P. deltoides × P. balsamifera), and exotic hybrids (trees bearing Populus nigra and P. maximowiczii genetic components) were screened for reproductive biomass, yield, seed germination, and fungal disease susceptibility. Exotic hybrids expressed fitness traits intermediate to pure species and were not significantly different from native hybrids. They formed fully viable seed and backcrossed predominantly with P. balsamifera. These data show that exotic hybrids were not unfit and were capable of establishing and competing within the native stand. Future research will seek to examine the impact of exotic gene regions on associated biotic communities to fully quantify the risk exotic poplars pose to native poplar forests. PMID:24963382

  8. Phenylcoumaran Benzylic Ether Reductase Prevents Accumulation of Compounds Formed under Oxidative Conditions in Poplar Xylem[W

    PubMed Central

    Niculaes, Claudiu; Morreel, Kris; Kim, Hoon; Lu, Fachuang; McKee, Lauren S.; Ivens, Bart; Haustraete, Jurgen; Vanholme, Bartel; Rycke, Riet De; Hertzberg, Magnus; Fromm, Jorg; Bulone, Vincent; Polle, Andrea; Ralph, John; Boerjan, Wout

    2014-01-01

    Phenylcoumaran benzylic ether reductase (PCBER) is one of the most abundant proteins in poplar (Populus spp) xylem, but its biological role has remained obscure. In this work, metabolite profiling of transgenic poplar trees downregulated in PCBER revealed both the in vivo substrate and product of PCBER. Based on mass spectrometry and NMR data, the substrate was identified as a hexosylated 8–5-coupling product between sinapyl alcohol and guaiacylglycerol, and the product was identified as its benzyl-reduced form. This activity was confirmed in vitro using a purified recombinant PCBER expressed in Escherichia coli. Assays performed on 20 synthetic substrate analogs revealed the enzyme specificity. In addition, the xylem of PCBER-downregulated trees accumulated over 2000-fold higher levels of cysteine adducts of monolignol dimers. These compounds could be generated in vitro by simple oxidative coupling assays involving monolignols and cysteine. Altogether, our data suggest that the function of PCBER is to reduce phenylpropanoid dimers in planta to form antioxidants that protect the plant against oxidative damage. In addition to describing the catalytic activity of one of the most abundant enzymes in wood, we provide experimental evidence for the antioxidant role of a phenylpropanoid coupling product in planta. PMID:25238751

  9. Strong RNAi-inhibition of 4CL expression alters lignification, saccharification potential and productivity of field-grown poplar

    SciTech Connect

    Tuskan, Gerald A; Gunter, Lee E; Strauss, S

    2007-01-01

    RNAi-associated down-regulation of the Pt4CL1 gene family encoding 4-coumarate:coenzyme A ligase (4CL) has been proposed as a means for reducing lignin content in cell walls, and thereby improving feedstock quality for paper and bioethanol production. Using hybrid poplars (Populus) we employed RNAi gene suppression of 4CL to generate 14 transgenic events and compared them to a non-transgenic control. After a two-year field trial we characterized the consequences of 4CL down-regulation on wood biochemistry and tree productivity. Lignin reductions correlated well with 4CL RNA expression, with a sharp decrease in lignin observed for RNA expression levels below ~50%. Lignin reductions greater than ~10% of the control value were associated with reduced productivity, decreased wood S/G (syringyl/guaiacyl) lignin monomer ratios, and increased incorporation of H-monomers (p-hydroxyphenyl) into cell walls. Strongly affected transgenic events were also characterized by patches of brown, discolored wood with about twice the extractive (complex polyphenolic) content of controls. There was no support for the hypothesis that reduced lignin would increase saccharification potential. The data presented suggest that a threshold of lignin reduction exists, beyond which there are large changes in wood chemistry and plant metabolism that affect productivity and potential ethanol yield.

  10. Genomic insights into salt adaptation in a desert poplar

    SciTech Connect

    Ma, Tao; Wang, Junyi; Zhou, Gongke; Yue, Zhen; Hu, Quanjun; Chen, Yan; Liu, Bingbing; Qiu, Qiang; Wang, Zhuo; Zhang, Jian; Wang, Kun; Jaing, Dechun; Gou, Caiyun; Yu, Lili; Zhan, Dongliang; Zhou, Ran; Luo, Wenchun; Ma, Hui; Yang, Yongzhi; Pan, Shengkai; Fang, Dongming; Luo, Yadan; Wang, Xia; Wang, Gaini; Wang, Juan; Wang, Qian; Lu, Xu; Chen, Zhe; Liu, Jinchao; Lu, Yao; Yin, Ye; Yang, Huanming; Abbott, Richard; Wu, Yuxia; Wan, Dongshi; Li, Jia; Yin, Tongming; Yin, Tongming; Lascoux, Martin; DiFazio, Steven P; Tuskan, Gerald A; Wang, Jun; Jianquan, Liu

    2013-01-01

    Despite the high economic and ecological importance of forests, our knowledge of the genomic evolution of trees under salt stress remains very limited. Here we report the genome sequence of the desert poplar, Populus euphratica, which exhibits high tolerance to sa lt stress. Its genome is very similar and collinear to that of the closely related mesophytic congener, P trichocarpa. However, we find that several gene families likely to be involved in tolerance to salt stress contain significantly more gene copies within the P euphratica lineage. Furthermore, genes showing evidence of positive selection are significantly enriched in functional categories related to salt stress. Some of these genes, and others within the same categories, are significantly upregulated under salt stress relative to their expression in another salt-sensitive poplar. Our results provide an important background for understanding tree adaptation to salt stress and facilitating the genetic improvement of cultivated poplars for saline soils.

  11. Hydrothermal pretreatment conditions to enhance ethanol production from poplar biomass.

    PubMed

    Negro, Maria José; Manzanares, Paloma; Ballesteros, Ignacio; Oliva, Jose Miguel; Cabañas, Araceli; Ballesteros, Mercedes

    2003-01-01

    Pretreatment has been recognized as a key step in enzyme-based conversion processes of lignocellulose biomass to ethanol. The aim of this study is to evaluate two hydrothermal pretreatments (steam explosion and liquid hot water) to enhance ethanol production from poplar (Populus nigra) biomass by a simultaneous saccharification and fermentation (SSF) process. The composition of liquid and solid fractions obtained after pretreatment, enzymatic digestibility, and ethanol production of poplar biomass pretreated at different experimental conditions was analyzed. The best results were obtained in steam explosion pretreatment at 210 C and 4 min, taking into account cellulose recovery above 95%, enzymatic hydrolysis yield of about 60%, SSF yield of 60% of theoretical, and 41% xylose recovery in the liquid fraction. Large particles can be used for poplar biomass in both pretreatments, since no significant effect of particle size on enzymatic hydrolysis and SSF was obtained.

  12. Effect of different biochars on Nitrogen uptake in poplar trees

    NASA Astrophysics Data System (ADS)

    George, Elizabeth; Tonon, Giustino; Scandellari, Francesca

    2014-05-01

    Influence of biochar on soil nitrogen transformation and plant uptake has been reported. This paper presents preliminary results of plant N uptake in poplars by using 15N isotope tracer approach Two types of biochar were applied to two sets of pots containing only sand and each pot received a pre-rooted poplar cutting. Half of the pots were inoculated with commercial mycorrhizal gel and the other half were left without. It is intended to provide information on how biochar, mycorrhiza and root interaction mediate nitrogen uptake and organ allocation.

  13. Effects of young poplar plantations on understory plant diversity in the Dongting Lake wetlands, China.

    PubMed

    Li, Youzhi; Chen, Xinsheng; Xie, Yonghong; Li, Xu; Li, Feng; Hou, Zhiyong

    2014-09-11

    This study evaluated the effects of young poplar plantations on understory plant diversity in the Dongting Lake wetlands, China. Poplar plantations resulted in a higher species number and Shannon's diversity. Species compositions were different between areas with poplar and reed populations: a lower ratio of hygrophytes but a higher ratio of mesophytes, and a higher ratio of heliophytes but a lower ratio of neutrophilous or shade plants in poplar areas compared to reed areas. Poplar plantations supported a higher ratio of ligneous plants in the entire Dongting Lake area, but there was no difference in the monitored plots. Unlike reedy areas, poplar plantations had higher light availability but lower soil water content during the growing seasons. These data suggest that young poplar plantations generally increased species richness and plant diversity, but significantly changed species composition due to the reduced soil water and increased light availability.

  14. Sense-, antisense- and RNAi-4CL1 regulate soluble phenolic acids, cell wall components and growth in transgenic Populus tomentosa Carr.

    PubMed

    Tian, Xiaoming; Xie, Jin; Zhao, Yanling; Lu, Hai; Liu, Shichang; Qu, Long; Li, Jianmei; Gai, Ying; Jiang, Xiangning

    2013-04-01

    Regulation of lignin biosynthesis affects plant growth and wood properties. Transgenic downregulation of 4-coumarate:coenzyme A ligase (4CL, EC 6.2.1.12) may reduce lignin content in cell walls, which could improve the qualities of pulp in papermaking and increase the efficiency of bioenergy applications. To determine the effects of Ptc4CL1 on lignin biosynthesis and plant growth, Populus tomentosa Carr. was transformed using sense-, antisense-, and RNAi-4CL1 genes. The growth properties, gene expression, enzyme activity, lignin content and composition and content of soluble phenolic acids were investigated in 1-year-old field-grown transgenic poplar trees. Transgenic up- and down-regulation of 4CL1 altered lignin content and composition in transgenic poplars, but there were no negative effects on the growth of transgenic plants. In addition, the severe changes in auxin observed in transgenic lines led to significantly enhanced growth performance. Furthermore, lignin content was tightly correlated with the alteration of 4CL1 enzymatic activity, which was correlated with 4CL1 gene expression. A significant increase in S units in lignin with a slight increase in sinapic acid was observed in 4CL1 down-regulated transgenic poplars. These results suggest that 4CL1 is a traffic control gene in monolignol biosynthesis and confirm that 4CL1 activity has been implicated with sinapoyl activation. Finally, our data demonstrate that there is cross-correlation among 4CL1 gene expression, 4CL1 enzyme activity, soluble phenolic acid, lignin monomer biosynthesis, and lignin content. PMID:23434928

  15. Isoprene synthesis in plants: lessons from a transgenic tobacco model.

    PubMed

    Vickers, Claudia E; Possell, Malcolm; Laothawornkitkul, Jullada; Ryan, Annette C; Hewitt, C Nicholas; Mullineaux, Philip M

    2011-06-01

    Isoprene is a highly reactive gas, and is emitted in such large quantities from the biosphere that it substantially affects the oxidizing potential of the atmosphere. Relatively little is known about the control of isoprene emission at the molecular level. Using transgenic tobacco lines harbouring a poplar isoprene synthase gene, we examined control of isoprene emission. Isoprene synthase required chloroplastic localization for catalytic activity, and isoprene was produced via the methyl erythritol (MEP) pathway from recently assimilated carbon. Emission patterns in transgenic tobacco plants were remarkably similar to naturally emitting plants under a wide variety of conditions. Emissions correlated with photosynthetic rates in developing and mature leaves, and with the amount of isoprene synthase protein in mature leaves. Isoprene synthase protein levels did not change under short-term increase in heat/light, despite an increase in emissions under these conditions. A robust circadian pattern could be observed in emissions from long-day plants. The data support the idea that substrate supply and changes in enzyme kinetics (rather than changes in isoprene synthase levels or post-translational regulation of activity) are the primary controls on isoprene emission in mature transgenic tobacco leaves.

  16. Nucleotide diversity and linkage disequilibrium in balsam poplar (Populus balsamifera).

    PubMed

    Olson, Matthew S; Robertson, Amanda L; Takebayashi, Naoki; Silim, Salim; Schroeder, William R; Tiffin, Peter

    2010-04-01

    *Current perceptions that poplars have high levels of nucleotide variation, large effective population sizes, and rapid decay of linkage disequilibrium are based primarily on studies from one poplar species, Populus tremula. *We analysed 590 gene fragments (average length 565 bp) from each of 15 individuals from different populations from throughout the range of Populus balsamifera. *Nucleotide diversity (theta(total) = 0.0028, pi = 0.0027) was low compared with other trees and model agricultural systems. Patterns of nucleotide diversity and site frequency spectra were consistent with purifying selection on replacement and intron sites. When averaged across all loci we found no evidence for decay of linkage disequilibrium across 750 bp, consistent with the low estimates of the scaled recombination parameter, rho = 0.0092. *Compared with P. tremula, a well studied congener with a similar distribution, P. balsamifera has low diversity and low effective recombination, both of which indicate a lower effective population size in P. balsamifera. Patterns of diversity and linkage indicate that there is considerable variation in population genomic patterns among poplar species and unlike P. tremula, association mapping techniques in balsam poplar should consider sampling single nucleotide polymorphisms (SNPs) at well-spaced intervals.

  17. Hydroponic screening of poplar for trace element tolerance and accumulation.

    PubMed

    Migeon, Aude; Richaud, Pierre; Guinet, Frédéric; Blaudez, Damien; Chalot, Michel

    2012-04-01

    Using the nutrient film technique, we screened 21 clones of poplar for growth in the presence of a mix of trace elements (TE) and for TE accumulation capacities. Poplar cuttings were exposed for four weeks to a multipollution solution consisting in 10 microM Cd, Cu, Ni, and Pb, and 200 microM Zn. Plant biomass and TE accumulation patterns in leaves varied greatly between clones. The highest Cd and Zn concentrations in leaves were detected in P. trichocarpa and P. trichocarpa hybrids, with the clone Skado (P. trichocarpa x P. maximowiczii) accumulating up to 108 mg Cd kg(-1) DW and 1510 mg Zn kg(-1) DW when exposed to a multipollution context. Our data also confirm the importance of pH and multipollution, as these factors greatly affect TE accumulation in above ground biomass. The NFT technique applied here to a large range of poplar clones also revealed the potential of the Rochester, AFO662 and AFO678 poplar clones for use in phytostabilization programs and bioenergy production, where production of less contaminated above ground biomass is suitable.

  18. Sulfate Metabolites of 4-Monochlorobiphenyl in Whole Poplar Plants

    PubMed Central

    Zhai, Guangshu; Lehmler, Hans-Joachim; Schnoor, Jerald L.

    2013-01-01

    4-Monochlorobiphenyl (PCB3) has been proven to be transformed into hydroxylated metabolites of PCB3 (OH-PCB3s) in whole poplar plants in our previous work. However, hydroxylated metabolites of PCBs, including OH-PCB3s, as the substrates of sulfotransferases have not been studied in many organisms including plants in vivo. Poplar (Populus deltoides × nigra, DN34) was used to investigate the further metabolism from OH-PCB3s to PCB3 sulfates because it is a model plant and one that is frequently utilized in phytoremediation. Results showed poplar plants could metabolize PCB3 into PCB3 sulfates during 25 day exposures. Three sulfate metabolites, including 2′-PCB3 sulfate, 3′-PCB3 sulfate and 4′-PCB3 sulfate, were identified in poplar roots and their concentrations increased in the roots from day 10 to day 25. The major products were 2′-PCB3 sulfate and 4′-PCB3 sulfate. However, the concentrations of PCB3 sulfates were much lower than those of OH-PCB3s in the roots, suggesting the sequential transformation of these hydroxylated PCB3 metabolites into PCB3 sulfates in whole poplars. In addition, 2′-PCB3 sulfate or 4′-PCB3 sulfate was also found in the bottom wood samples indicating some translocation or metabolism in woody tissue. Results suggested that OH-PCB3s were the substrates of sulfotransferases which catalyzed the formation of PCB3 sulfates in the metabolic pathway of PCB3. PMID:23215248

  19. Isoprene emission-free poplars--a chance to reduce the impact from poplar plantations on the atmosphere.

    PubMed

    Behnke, Katja; Grote, Rüdiger; Brüggemann, Nicolas; Zimmer, Ina; Zhou, Guanwu; Elobeid, Mudawi; Janz, Dennis; Polle, Andrea; Schnitzler, Jörg-Peter

    2012-04-01

    • Depending on the atmospheric composition, isoprene emissions from plants can have a severe impact on air quality and regional climate. For the plant itself, isoprene can enhance stress tolerance and also interfere with the attraction of herbivores and parasitoids. • Here, we tested the growth performance and fitness of Populus × canescens in which isoprene emission had been knocked down by RNA interference technology (PcISPS-RNAi plants) for two growing seasons under outdoor conditions. • Neither the growth nor biomass yield of the PcISPS-RNAi poplars was impaired, and they were even temporarily enhanced compared with control poplars. Modelling of the annual carbon balances revealed a reduced carbon loss of 2.2% of the total gross primary production by the absence of isoprene emission, and a 6.9% enhanced net growth of PcISPS-RNAi poplars. However, the knock down in isoprene emission resulted in reduced susceptibility to fungal infection, whereas the attractiveness for herbivores was enhanced. • The present study promises potential for the use of non- or low-isoprene-emitting poplars for more sustainable and environmentally friendly biomass production, as reducing isoprene emission will presumably have positive effects on regional climate and air quality.

  20. Matrix attachment region elements have small and variable effects on transgene expression and stability in field-grown Populus.

    PubMed

    Li, Jingyi; Brunner, Amy M; Meilan, Richard; Strauss, Steven H

    2008-12-01

    Matrix attachment regions (MARs) are thought to buffer transgenes from the influence of surrounding chromosomal sequences, and therefore to reduce transgene silencing and variation in expression. The statistical properties of more than 400 independent transgenic events produced in Populus, with and without flanking MAR elements from the tobacco root gene RB7, were analysed. The expression of two reporter genes in two poplar clones during three phases of vegetative growth, and the association of T-DNA characteristics with expression, was examined. It was found that MARs did not show a consistent effect on transgene expression levels; they had no effect on the green fluorescent protein (GFP) reporter gene, but reduced expression in the Basta resistance (BAR) reporter gene by 23%. The presence of MARs reduced expression variability within transformant populations, apparently by reducing the number of silenced or weakly expressing events. Transgene expression was highly stable over vegetative growth cycles that spanned 3 years of growth in the glasshouse and field, but MARs showed no association with the strength of correlations in expression over the years. Nonetheless, MARs increased the correlation in expression between a p35S::GFP and prbcS::BAR transgene linked on the same vector, but the effect was small and varied between the years. The presence of MARs had no effect on the transgene copy number, but was positively associated with T-DNA truncations, as well as with the formation of direct over inverted repeats at the same chromosomal locus. PMID:19548343

  1. Antisense expression of the fasciclin-like arabinogalactan protein FLA6 gene in Populus inhibits expression of its homologous genes and alters stem biomechanics and cell wall composition in transgenic trees.

    PubMed

    Wang, Haihai; Jiang, Chunmei; Wang, Cuiting; Yang, Yang; Yang, Lei; Gao, Xiaoyan; Zhang, Hongxia

    2015-03-01

    Fasciclin-like arabinogalactan proteins (FLAs) play important roles in the growth and development of roots, stems, and seeds in Arabidopsis. However, their biological functions in woody plants are largely unknown. In this work, we investigated the possible function of PtFLA6 in poplar. Quantitative real-time PCR, PtFLA6-yellow fluorescent protein (YFP) fusion protein subcellular localization, Western blotting, and immunohistochemical analyses demonstrated that the PtFLA6 gene was expressed specifically in the xylem of mature stem, and PtFLA6 protein was distributed ubiquitous in plant cells and accumulated predominantly in stem xylem fibres. Antisense expression of PtFLA6 in the aspen hybrid clone Poplar davidiana×Poplar bolleana reduced the transcripts of PtFLA6 and its homologous genes. Transgenic plants that showed a significant reduction in the transcripts of PtFLAs accumulated fewer PtFLA6 and arabinogalactan proteins than did the non-transgenic plants, leading to reduced stem flexural strength and stiffness. Further studies revealed that the altered stem biomechanics of transgenic plants could be attributed to the decreased cellulose and lignin composition in the xylem. In addition expression of some xylem-specific genes involved in cell wall biosynthesis was downregulated in these transgenic plants. All these results suggest that engineering the expression of PtFLA6 and its homologues could modulate stem mechanical properties by affecting cell wall composition in trees.

  2. Antisense expression of the fasciclin-like arabinogalactan protein FLA6 gene in Populus inhibits expression of its homologous genes and alters stem biomechanics and cell wall composition in transgenic trees

    PubMed Central

    Wang, Haihai; Jiang, Chunmei; Wang, Cuiting; Yang, Yang; Yang, Lei; Gao, Xiaoyan; Zhang, Hongxia

    2015-01-01

    Fasciclin-like arabinogalactan proteins (FLAs) play important roles in the growth and development of roots, stems, and seeds in Arabidopsis. However, their biological functions in woody plants are largely unknown. In this work, we investigated the possible function of PtFLA6 in poplar. Quantitative real-time PCR, PtFLA6–yellow fluorescent protein (YFP) fusion protein subcellular localization, Western blotting, and immunohistochemical analyses demonstrated that the PtFLA6 gene was expressed specifically in the xylem of mature stem, and PtFLA6 protein was distributed ubiquitous in plant cells and accumulated predominantly in stem xylem fibres. Antisense expression of PtFLA6 in the aspen hybrid clone Poplar davidiana×Poplar bolleana reduced the transcripts of PtFLA6 and its homologous genes. Transgenic plants that showed a significant reduction in the transcripts of PtFLAs accumulated fewer PtFLA6 and arabinogalactan proteins than did the non-transgenic plants, leading to reduced stem flexural strength and stiffness. Further studies revealed that the altered stem biomechanics of transgenic plants could be attributed to the decreased cellulose and lignin composition in the xylem. In addition expression of some xylem-specific genes involved in cell wall biosynthesis was downregulated in these transgenic plants. All these results suggest that engineering the expression of PtFLA6 and its homologues could modulate stem mechanical properties by affecting cell wall composition in trees. PMID:25428999

  3. Winter chemical defense of Alaskan balsam poplar against snowshoe hares.

    PubMed

    Reichardt, P B; Bryant, J P; Mattes, B R; Clausen, T P; Chapin, F S; Meyer, M

    1990-06-01

    Palatabilities of parts and growth stages of balsam poplar (Populus balsamifera) to snowshoe hares (Lepus americanus) are related to concentrations of specific plant metabolites that act as antifeedants. Buds are defended from hares by cineol, benzyl alcohol, and (+)-α-bisabolol. Internodes are defended by 6-hydroxycylohexenone (6-HCH) and salicaldehyde. Although defense of interaodes depends upon both compounds, the defense of juvenile internodes is principally related to salicaldehyde concentration; the defense of internode current annual growth is principally related to 6-HCH concentration. The concentration of 6-HCH can be supplemented by the hydrolysis of phenol glycosides when plant tissue is disrupted, raising the possibility of a dynamic element of the chemical defense of poplar.

  4. Nitrogen ion utilization by tulip poplar (Liriodendron tulipifera L. ) seedlings

    SciTech Connect

    Mann, L.K.

    1982-01-01

    Growth responses of one-year-old tulip poplar seedlings were determined for different nitrogen sources (HN/sub 4/NO/sub 3/, NH+/sub 4/, NO-/sub 3/, no nitrogen) at 336 ppm N in nutrient culture. At the end of three months, there were no significant differences in growth observed among treatments in terms of stem elongation, leaf area, and leaf size. After four months, however, seedlings of the NH/sub 4/NO/sub 3/ treatment exhibited significantly (P<0.05) greater growth (final weight gain and stem elongation) than all other nitrogen sorces. Growth was slightly less for the NO-/sub 3/ treatment plants, but compared with NH+/sub 4/ and no nitrogen treatment, both NH/sub 4/NO/sub 3/ and NO-/sub 3/ treatments exhibited significantly greater growth responses. NO-/sub 3/ is recommended as the sole nitrogen source, especially for small seedlings of tulip poplar.

  5. Transgenic plants for phytoremediation: helping nature to clean up environmental pollution.

    PubMed

    Van Aken, Benoit

    2008-05-01

    Phytoremediation is the use of plants to clean up environmental pollution. However, detoxification of organic pollutants by plants is often slow, leading to the accumulation of toxic compounds that could be later released into the environment. A recent publication by Doty and colleagues describes the development of transgenic poplars (Populus) overexpressing a mammalian cytochrome P450, a family of enzymes commonly involved in the metabolism of toxic compounds. The engineered plants showed enhanced performance with regards to the metabolism of trichloroethylene and the removal of a range of other toxic volatile organic pollutants, including vinyl chloride, carbon tetrachloride, chloroform and benzene. This work suggests that transgenic plants might be able to contribute to the wider and safer application of phytoremediation.

  6. Poplar for the phytomanagement of boron contaminated sites.

    PubMed

    Robinson, B H; Green, S R; Chancerel, B; Mills, T M; Clothier, B E

    2007-11-01

    Boron (B) is a widespread environmental contaminant that is mobile relative to other trace elements. We investigated the potential of hybrid poplar (Populus sp.) for B phytomanagement using a lysimeter experiment and a field trial on B-contaminated wood-waste. In both studies, poplars enhanced evapotranspiration from the wood-waste, reduced B leaching, and accumulated B in the aerial portions of the tree. When grown in a substrate containing 30 mg/kg B, poplar leaves had an average B concentration of 845 mg/kg, while the stems contained 21 mg/kg B. Leaf B concentrations increased linearly with leaf age. A decomposition experiment revealed that abscised leaves released 14% of their B during the winter months. Fertiliser application enhanced tree growth without decreasing the leaf B concentrations. Harvesting alternate rows of trees on a contaminated site would reduce leaching from the site while removing B. Harvested plant material may provide bioenergy, stock fodder, or an amendment for B-deficient soils. PMID:17382438

  7. Heat transfer mechanisms in poplar wood undergoing torrefaction

    NASA Astrophysics Data System (ADS)

    Sule, Idris O.; Mahmud, Shohel; Dutta, Animesh; Tasnim, Syeda Humaira

    2016-03-01

    Torrefaction, a thermal treatment process of biomass, has been proved to improve biomass combustible properties. Torrefaction is defined as a thermochemical process in reduced oxygen condition and at temperature range from 200 to 300 °C for shorter residence time whereby energy yield is maximized, can be a bridging technology that can lead the conventional system (e.g. coal-fired plants) towards a sustainable energy system. In efforts to develop a commercial operable torrefaction reactor, the present study examines the minimum input condition at which biomass is torrefied and explores the heat transfer mechanisms during torrefaction in poplar wood samples. The heat transfer through the wood sample is numerically modeled and analyzed. Each poplar wood is torrefied at temperature of 250, 270, and 300 °C. The experimental study shows that the 270 °C-treatment can be deduced as the optimal input condition for torrefaction of poplar wood. A good understanding of heat transfer mechanisms can facilitate the upscaling and downscaling of torrefaction process equipment to fit the feedstock input criteria and can help to develop treatment input specifications that can maximize process efficiency.

  8. Relationship between genotype and soil environment during colonization of poplar roots by mycorrhizal and endophytic fungi.

    PubMed

    Karliński, Leszek; Rudawska, Maria; Kieliszewska-Rokicka, Barbara; Leski, Tomasz

    2010-06-01

    Poplars are among the few tree genera that can develop both ectomycorrhizal (ECM) and arbuscular (AM) associations; however, variable ratios of ECM/AM in dual mycorrhizal colonizations were observed in the roots of a variety of poplar species and hybrids. The objective of our study was to analyze the effect of internal and external factors on growth and dual AM and ECM colonization of poplar roots in three 12-15-year-old common gardens in Poland. We also analyzed the abundance of nonmycorrhizal fungal endophytes in the poplar roots. The Populus clones comprised black poplars (Populus deltoides and P. deltoides x Populus nigra), balsam poplars (Populus maximowiczii x Populus trichocarpa), and a hybrid of black and balsam poplars (P. deltoides x P. trichocarpa). Of the three sites that we studied, one was located in the vicinity of a copper smelter, where soil was contaminated with copper and lead. Poplar root tip abundance, mycorrhizal colonization, and soil fungi biomass were lower at this heavily polluted site. The total mycorrhizal colonization and the ratio of ECM and AM colonization differed among the study sites and according to soil depth. The influence of Populus genotype was significantly pronounced only within the individual study sites. The contribution of nonmycorrhizal fungal endophytes differed among the poplar clones and was higher at the polluted site than at the sites free of pollution. Our results indicate that poplar fine root abundance and AM and ECM symbiosis are influenced by environmental conditions. Further studies of different site conditions are required to characterize the utility of poplars for purposes such as the phytoremediation of polluted sites. PMID:19921284

  9. Relationship between genotype and soil environment during colonization of poplar roots by mycorrhizal and endophytic fungi.

    PubMed

    Karliński, Leszek; Rudawska, Maria; Kieliszewska-Rokicka, Barbara; Leski, Tomasz

    2010-06-01

    Poplars are among the few tree genera that can develop both ectomycorrhizal (ECM) and arbuscular (AM) associations; however, variable ratios of ECM/AM in dual mycorrhizal colonizations were observed in the roots of a variety of poplar species and hybrids. The objective of our study was to analyze the effect of internal and external factors on growth and dual AM and ECM colonization of poplar roots in three 12-15-year-old common gardens in Poland. We also analyzed the abundance of nonmycorrhizal fungal endophytes in the poplar roots. The Populus clones comprised black poplars (Populus deltoides and P. deltoides x Populus nigra), balsam poplars (Populus maximowiczii x Populus trichocarpa), and a hybrid of black and balsam poplars (P. deltoides x P. trichocarpa). Of the three sites that we studied, one was located in the vicinity of a copper smelter, where soil was contaminated with copper and lead. Poplar root tip abundance, mycorrhizal colonization, and soil fungi biomass were lower at this heavily polluted site. The total mycorrhizal colonization and the ratio of ECM and AM colonization differed among the study sites and according to soil depth. The influence of Populus genotype was significantly pronounced only within the individual study sites. The contribution of nonmycorrhizal fungal endophytes differed among the poplar clones and was higher at the polluted site than at the sites free of pollution. Our results indicate that poplar fine root abundance and AM and ECM symbiosis are influenced by environmental conditions. Further studies of different site conditions are required to characterize the utility of poplars for purposes such as the phytoremediation of polluted sites.

  10. Effective alkaline metal-catalyzed oxidative delignification of hybrid poplar

    DOE PAGESBeta

    Bhalla, Aditya; Bansal, Namita; Stoklosa, Ryan J.; Fountain, Mackenzie; Ralph, John; Hodge, David B.; Hegg, Eric L.

    2016-02-09

    Background: Strategies to improve copper-catalyzed alkaline hydrogen peroxide (Cu-AHP) pretreatment of hybrid poplar were investigated. These improvements included a combination of increasing hydrolysis yields, while simultaneously decreasing process inputs through (i) more efficient utilization of H2O2 and (ii) the addition of an alkaline extraction step prior to the metal-catalyzed AHP pretreatment. We hypothesized that utilizing this improved process could substantially lower the chemical inputs needed during pretreatment. Results: Hybrid poplar was pretreated utilizing a modified process in which an alkaline extraction step was incorporated prior to the Cu-AHP treatment step and H2O2 was added batch-wise over the course of 10more » h. Our results revealed that the alkaline pre-extraction step improved both lignin and xylan solubilization, which ultimately led to improved glucose (86 %) and xylose (95 %) yields following enzymatic hydrolysis. An increase in the lignin solubilization was also observed with fed-batch H2O2 addition relative to batch-only addition, which again resulted in increased glucose and xylose yields (77 and 93 % versus 63 and 74 %, respectively). Importantly, combining these strategies led to significantly improved sugar yields (96 % glucose and 94 % xylose) following enzymatic hydrolysis. In addition, we found that we could substantially lower the chemical inputs (enzyme, H2O2, and catalyst), while still maintaining high product yields utilizing the improved Cu-AHP process. This pretreatment also provided a relatively pure lignin stream consisting of ≥90 % Klason lignin and only 3 % xylan and 2 % ash following precipitation. Two-dimensional heteronuclear single-quantum coherence (2D HSQC) NMR and size-exclusion chromatography demonstrated that the solubilized lignin was high molecular weight (Mw ≈ 22,000 Da) and only slightly oxidized relative to lignin from untreated poplar. In conclusion: This study demonstrated that the fed

  11. Fitness dynamics within a poplar hybrid zone: I. Prezygotic and postzygotic barriers impacting a native poplar hybrid stand.

    PubMed

    Roe, Amanda D; MacQuarrie, Chris J K; Gros-Louis, Marie-Claude; Simpson, J Dale; Lamarche, Josyanne; Beardmore, Tannis; Thompson, Stacey L; Tanguay, Philippe; Isabel, Nathalie

    2014-05-01

    Hybridization and introgression are pervasive evolutionary phenomena that provide insight into the selective forces that maintain species boundaries, permit gene flow, and control the direction of evolutionary change. Poplar trees (Populus L.) are well known for their ability to form viable hybrids and maintain their distinct species boundaries despite this interspecific gene flow. We sought to quantify the hybridization dynamics and postzygotic fitness within a hybrid stand of balsam poplar (Populus balsamifera L.), eastern cottonwood (P. deltoides Marsh.), and their natural hybrids to gain insight into the barriers maintaining this stable hybrid zone. We observed asymmetrical hybrid formation with P. deltoides acting as the seed parent, but with subsequent introgression biased toward P. balsamifera. Native hybrids expressed fitness traits intermediate to the parental species and were not universally unfit. That said, native hybrid seedlings were absent from the seedling population, which may indicate additional selective pressures controlling their recruitment. It is imperative that we understand the selective forces maintaining this native hybrid zone in order to quantify the impact of exotic poplar hybrids on this native system.

  12. Fitness dynamics within a poplar hybrid zone: I. Prezygotic and postzygotic barriers impacting a native poplar hybrid stand

    PubMed Central

    Roe, Amanda D; MacQuarrie, Chris J K; Gros-Louis, Marie-Claude; Simpson, J Dale; Lamarche, Josyanne; Beardmore, Tannis; Thompson, Stacey L; Tanguay, Philippe; Isabel, Nathalie

    2014-01-01

    Hybridization and introgression are pervasive evolutionary phenomena that provide insight into the selective forces that maintain species boundaries, permit gene flow, and control the direction of evolutionary change. Poplar trees (Populus L.) are well known for their ability to form viable hybrids and maintain their distinct species boundaries despite this interspecific gene flow. We sought to quantify the hybridization dynamics and postzygotic fitness within a hybrid stand of balsam poplar (Populus balsamifera L.), eastern cottonwood (P. deltoides Marsh.), and their natural hybrids to gain insight into the barriers maintaining this stable hybrid zone. We observed asymmetrical hybrid formation with P. deltoides acting as the seed parent, but with subsequent introgression biased toward P. balsamifera. Native hybrids expressed fitness traits intermediate to the parental species and were not universally unfit. That said, native hybrid seedlings were absent from the seedling population, which may indicate additional selective pressures controlling their recruitment. It is imperative that we understand the selective forces maintaining this native hybrid zone in order to quantify the impact of exotic poplar hybrids on this native system. PMID:24967081

  13. Transgenic modification of gai or rg/1 causes dwarfing and alters gibberellins, root growth, and metabolite profiles in Populus

    SciTech Connect

    Tschaplinski, Timothy J; Busov, V.; Meilan, R; Pearce, D; Rood, s; Ma, C; Strauss, S

    2006-01-01

    In Arabidopsis and other plants, gibberellin (GA)-regulated responses are mediated by proteins including GAI, RGA and RGL1-3 that contain a functional DELLA domain. Through transgenic modification, we found that DELLA-less versions of GAI (gai) and RGL1 (rgl1) in a Populus tree have profound, dominant effects on phenotype, producing pleiotropic changes in morphology and metabolic profiles. Shoots were dwarfed, likely via constitutive repression of GA-induced elongation, whereas root growth was promoted two- to threefold in vitro. Applied GA{sub 3} inhibited adventitious root production in wild-type poplar, but gai/rgl1 poplars were unaffected by the inhibition. The concentrations of bioactive GA{sub 1} and GA{sub 4} in leaves of gai- and rgl1-expressing plants increased 12- to 64-fold, while the C{sub 19} precursors of GA{sub 1} (GA{sub 53}, GA{sub 44} and GA{sub 19}) decreased three- to ninefold, consistent with feedback regulation of GA 20-oxidase in the transgenic plants. The transgenic modifications elicited significant metabolic changes. In roots, metabolic profiling suggested increased respiration as a possible mechanism of the increased root growth. In leaves, we found metabolite changes suggesting reduced carbon flux through the lignin biosynthetic pathway and a shift towards allocation of secondary storage and defense metabolites, including various phenols, phenolic glucosides, and phenolic acid conjugates.

  14. Transgenic Crops for Herbicide Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since their introduction in 1995, crops made resistant to the broad-spectrum herbicides glyphosate and glufosinate with transgenes are widely available and used in much of the world. As of 2008, over 80% of the transgenic crops grown world-wide have this transgenic trait. This technology has had m...

  15. WUS and STM-based reporter genes for studying meristem development in poplar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We describe the development of a reporter system for monitoring meristem initiation in poplar using promoters of poplar homologs to the meristem-active regulatory genes WUSCHEL (WUS) and SHOOTMERISTEMLESS (STM). When ~3 kb of the 5’ flanking regions of close homologs were used to drive expression o...

  16. Transgenic animal bioreactors.

    PubMed

    Houdebine, L M

    2000-01-01

    The production of recombinant proteins is one of the major successes of biotechnology. Animal cells are required to synthesize proteins with the appropriate post-translational modifications. Transgenic animals are being used for this purpose. Milk, egg white, blood, urine, seminal plasma and silk worm cocoon from transgenic animals are candidates to be the source of recombinant proteins at an industrial scale. Although the first recombinant protein produced by transgenic animals is expected to be in the market in 2000, a certain number of technical problems remain to be solved before the various systems are optimized. Although the generation of transgenic farm animals has become recently easier mainly with the technique of animal cloning using transfected somatic cells as nuclear donor, this point remains a limitation as far as cost is concerned. Numerous experiments carried out for the last 15 years have shown that the expression of the transgene is predictable only to a limited extent. This is clearly due to the fact that the expression vectors are not constructed in an appropriate manner. This undoubtedly comes from the fact that all the signals contained in genes have not yet been identified. Gene constructions thus result sometime in poorly functional expression vectors. One possibility consists in using long genomic DNA fragments contained in YAC or BAC vectors. The other relies on the identification of the major important elements required to obtain a satisfactory transgene expression. These elements include essentially gene insulators, chromatin openers, matrix attached regions, enhancers and introns. A certain number of proteins having complex structures (formed by several subunits, being glycosylated, cleaved, carboxylated...) have been obtained at levels sufficient for an industrial exploitation. In other cases, the mammary cellular machinery seems insufficient to promote all the post-translational modifications. The addition of genes coding for enzymes

  17. Regulation of secondary cell wall biosynthesis by poplar R2R3 MYB transcription factor PtrMYB152 in Arabidopsis

    SciTech Connect

    Wang, Shucai; Li, Eryang; Porth, Ilga; Chen, Jin-Gui; Mansfield, Shawn D.; Douglas, Carl

    2014-05-23

    Poplar has 192 annotated R2R3 MYB genes, of which only three have been shown to play a role in the regulation of secondary cell wall formation. Here we report the characterization of PtrMYB152, a poplar homolog of the Arabidopsis R2R3 MYB transcription factor AtMYB43, in the regulation of secondary cell wall biosynthesis. The expression of PtrMYB152 in secondary xylem is about 18 times of that in phloem. When expressed in Arabidopsis under the control of either 35S or PtrCesA8 promoters, PtrMYB152 increased secondary cell wall thickness, which is likely caused by increased lignification. Accordingly, elevated expression of genes encoding sets of enzymes in secondary wall biosynthesis were observed in transgenic plants expressing PtrMYB152. Arabidopsis protoplast transfection assays suggested that PtrMYB152 functions as a transcriptional activator. Taken together, our results suggest that PtrMYB152 may be part of a regulatory network activating expression of discrete sets of secondary cell wall biosynthesis genes.

  18. Regulation of secondary cell wall biosynthesis by poplar R2R3 MYB transcription factor PtrMYB152 in Arabidopsis

    PubMed Central

    Wang, Shucai; Li, Eryang; Porth, Ilga; Chen, Jin-Gui; Mansfield, Shawn D.; Douglas, Carl J.

    2014-01-01

    Poplar has 192 annotated R2R3 MYB genes, of which only three have been shown to play a role in the regulation of secondary cell wall formation. Here we report the characterization of PtrMYB152, a poplar homolog of the Arabidopsis R2R3 MYB transcription factor AtMYB43, in the regulation of secondary cell wall biosynthesis. The expression of PtrMYB152 in secondary xylem is about 18 times of that in phloem. When expressed in Arabidopsis under the control of either 35S or PtrCesA8 promoters, PtrMYB152 increased secondary cell wall thickness, which is likely caused by increased lignification. Accordingly, elevated expression of genes encoding sets of enzymes in secondary wall biosynthesis were observed in transgenic plants expressing PtrMYB152. Arabidopsis protoplast transfection assays suggested that PtrMYB152 functions as a transcriptional activator. Taken together, our results suggest that PtrMYB152 may be part of a regulatory network activating expression of discrete sets of secondary cell wall biosynthesis genes. PMID:24852237

  19. Antisense Down-Regulation of 4CL Expression Alters Lignification, Tree Growth, and Saccharification Potential of Field-Grown Poplar1[W][OA

    PubMed Central

    Voelker, Steven L.; Lachenbruch, Barbara; Meinzer, Frederick C.; Jourdes, Michael; Ki, Chanyoung; Patten, Ann M.; Davin, Laurence B.; Lewis, Norman G.; Tuskan, Gerald A.; Gunter, Lee; Decker, Stephen R.; Selig, Michael J.; Sykes, Robert; Himmel, Michael E.; Kitin, Peter; Shevchenko, Olga; Strauss, Steven H.

    2010-01-01

    Transgenic down-regulation of the Pt4CL1 gene family encoding 4-coumarate:coenzyme A ligase (4CL) has been reported as a means for reducing lignin content in cell walls and increasing overall growth rates, thereby improving feedstock quality for paper and bioethanol production. Using hybrid poplar (Populus tremula × Populus alba), we applied this strategy and examined field-grown transformants for both effects on wood biochemistry and tree productivity. The reductions in lignin contents obtained correlated well with 4CL RNA expression, with a sharp decrease in lignin amount being observed for RNA expression below approximately 50% of the nontransgenic control. Relatively small lignin reductions of approximately 10% were associated with reduced productivity, decreased wood syringyl/guaiacyl lignin monomer ratios, and a small increase in the level of incorporation of H-monomers (p-hydroxyphenyl) into cell walls. Transgenic events with less than approximately 50% 4CL RNA expression were characterized by patches of reddish-brown discolored wood that had approximately twice the extractive content of controls (largely complex polyphenolics). There was no evidence that substantially reduced lignin contents increased growth rates or saccharification potential. Our results suggest that the capacity for lignin reduction is limited; below a threshold, large changes in wood chemistry and plant metabolism were observed that adversely affected productivity and potential ethanol yield. They also underline the importance of field studies to obtain physiologically meaningful results and to support technology development with transgenic trees. PMID:20729393

  20. Metagenome of an Anaerobic Microbial Community Decomposing Poplar Wood Chips

    SciTech Connect

    van der Lelie, D.; Taghavi, S.; McCorkle, S. M.; Li, L. L.; Malfatti, S. A.; Monteleone, D.; Donohoe, B. S.; Ding, S. Y.; Adney, W. S.; Himmel, M. E.; Tringe, S. G.

    2012-05-01

    This study describes the composition and metabolic potential of a lignocellulosic biomass degrading community that decays poplar wood chips under anaerobic conditions. We examined the community that developed on poplar biomass in a non-aerated bioreactor over the course of a year, with no microbial inoculation other than the naturally occurring organisms on the woody material. The composition of this community contrasts in important ways with biomass-degrading communities associated with higher organisms, which have evolved over millions of years into a symbiotic relationship. Both mammalian and insect hosts provide partial size reduction, chemical treatments (low or high pH environments), and complex enzymatic 'secretomes' that improve microbial access to cell wall polymers. We hypothesized that in order to efficiently degrade coarse untreated biomass, a spontaneously assembled free-living community must both employ alternative strategies, such as enzymatic lignin depolymerization, for accessing hemicellulose and cellulose and have a much broader metabolic potential than host-associated communities. This would suggest that such a community would make a valuable resource for finding new catalytic functions involved in biomass decomposition and gaining new insight into the poorly understood process of anaerobic lignin depolymerization. Therefore, in addition to determining the major players in this community, our work specifically aimed at identifying functions potentially involved in the depolymerization of cellulose, hemicelluloses, and lignin, and to assign specific roles to the prevalent community members in the collaborative process of biomass decomposition. A bacterium similar to Magnetospirillum was identified among the dominant community members, which could play a key role in the anaerobic breakdown of aromatic compounds. We suggest that these compounds are released from the lignin fraction in poplar hardwood during the decay process, which would point to

  1. New hydroxylated metabolites of 4-monochlorobiphenyl in whole poplar plants

    PubMed Central

    2011-01-01

    Two new monohydroxy metabolites of 4-monochlorobiphenyl (CB3) were positively identified using three newly synthesized monohydroxy compounds of CB3: 2-hydroxy-4-chlorobiphenyl (2OH-CB3), 3-hydroxy-4-chlorobiphenyl (3OH-CB3) and 4-hydroxy-3-chlorobiphenyl (4OH-CB2). New metabolites of CB3, including 2OH-CB3 and 3OH-CB3, were confirmed in whole poplars (Populus deltoides × nigra, DN34), a model plant in the application of phytoremediation. Furthermore, the concentrations and masses of 2OH-CB3 and 3OH-CB3 formed in various tissues of whole poplar plants and controls were measured. Results showed that 2OH-CB3 was the major product in these two OH-CB3s with chlorine and hydroxyl moieties in the same phenyl ring of CB3. Masses of 2OH-CB3 and 3OH-CB3 in tissues of whole poplar plants were much higher than those in the hydroponic solution, strongly indicating that the poplar plant itself metabolizes CB3 to both 2OH-CB3 and 3OH-CB3. The total yield of 2OH-CB3 and 3OH-CB3, with chlorine and hydroxyl in the same phenyl ring of CB3, was less than that of three previously found OH-CB3s with chlorine and hydroxyl in the opposite phenyl rings of CB3 (2'OH-CB3, 3'OH-CB3, and 4'OH-CB3). Finally, these two newly detected OH-CB3s from CB3 in this work also suggests that the metabolic pathway was via epoxide intermediates. These five OH-CB3s clearly showed the complete metabolism profile from CB3 to monohydroxylated CB3. More importantly, it's the first report and confirmation of 2OH-CB3 and 3OH-CB3 (new metabolites of CB3) in a living organism. PMID:22185578

  2. Transgenes for tea?

    PubMed

    Heritage, John

    2005-01-01

    So far, no compelling scientific evidence has been found to suggest that the consumption of transgenic or genetically modified (GM) plants by animals or humans is more likely to cause harm than is the consumption of their conventional counterparts. Despite this lack of scientific evidence, the economic prospects for GM plants are probably limited in the short term and there is public opposition to the technology. Now is a good time to address several issues concerning GM plants, including the potential for transgenes to migrate from GM plants to gut microbes or to animal or human tissues, the consequences of consuming GM crops, either as fresh plants or as silage, and the problems caused by current legislation on GM labelling and beyond.

  3. Transgenics in crops

    NASA Technical Reports Server (NTRS)

    Li, Y.; Wu, Y. H.; McAvoy, R.; Duan, H.

    2001-01-01

    With rapid world population growth and declining availability of fresh water and arable land, a new technology is urgently needed to enhance agricultural productivity. Recent discoveries in the field of crop transgenics clearly demonstrate the great potential of this technology for increasing food production and improving food quality while preserving the environment for future generations. In this review, we briefly discuss some of the recent achievements in crop improvement that have been made using gene transfer technology.

  4. Using corngrass1 to engineer poplar as a bioenergy crop

    DOEpatents

    Meilan, Richard; Rubinelli, Peter Marius; Chuck, George

    2016-05-10

    Embodiments of the present invention relate generally to new bioenergy crops and methods of creating new bioenergy crops. For example, genes encoding microRNAs (miRNAs) are used to create transgenic crops. In some embodiments, over-expression of miRNA is used to produce transgenic perennials, such as trees, with altered lignin content or composition. In some embodiments, the transgenic perennials are Populus spp. In some embodiments, the miRNA is a member of the miR156 family. In some embodiments, the gene is Zea mays Cg1.

  5. Major Chromosomal Rearrangements Distinguish Willow and Poplar After the Ancestral "Salicoid" Genome Duplication.

    PubMed

    Hou, Jing; Ye, Ning; Dong, Zhongyuan; Lu, Mengzhu; Li, Laigeng; Yin, Tongming

    2016-01-01

    Populus (poplar) and Salix (willow) are sister genera in the Salicaceae family. In both lineages extant species are predominantly diploid. Genome analysis previously revealed that the two lineages originated from a common tetraploid ancestor. In this study, we conducted a syntenic comparison of the corresponding 19 chromosome members of the poplar and willow genomes. Our observations revealed that almost every chromosomal segment had a parallel paralogous segment elsewhere in the genomes, and the two lineages shared a similar syntenic pinwheel pattern for most of the chromosomes, which indicated that the two lineages diverged after the genome reorganization in the common progenitor. The pinwheel patterns showed distinct differences for two chromosome pairs in each lineage. Further analysis detected two major interchromosomal rearrangements that distinguished the karyotypes of willow and poplar. Chromosome I of willow was a conjunction of poplar chromosome XVI and the lower portion of poplar chromosome I, whereas willow chromosome XVI corresponded to the upper portion of poplar chromosome I. Scientists have suggested that Populus is evolutionarily more primitive than Salix. Therefore, we propose that, after the "salicoid" duplication event, fission and fusion of the ancestral chromosomes first give rise to the diploid progenitor of extant Populus species. During the evolutionary process, fission and fusion of poplar chromosomes I and XVI subsequently give rise to the progenitor of extant Salix species. This study contributes to an improved understanding of genome divergence after ancient genome duplication in closely related lineages of higher plants. PMID:27352946

  6. Nitrogen fertilizer and sewage sludge effects on hybrid poplars. Final report

    SciTech Connect

    Riha, S.R.; Senesac, G.P.; Naylor, L.

    1985-01-01

    Experiments conducted in the greenhouse compared the growth and nutrient and heavy metal uptake in two clones of hybrid poplar grown in soil amended with nitrogen fertilizer or sewage sludge. In addition, poplar responses to weed competition and to rooting prior to planting were investigated. Both fertilizer and sludge application increased poplar stem biomass. Weeds reduced poplar biomass. The large difference in root biomass of the two poplar clones may account for different effects weed and sludge application had on nutrient and heavy metal uptake in each clone. The relatively small root biomass of I-45/51 increased with increasing sludge application, as did the uptake of nutrients and heavy metals. The relatively large root biomass of clone NE-510 was reduced when weeds were present, as was nutrient and heavy metal uptake. Other results suggest that poplars with low root-to-stem ratios may be most affected by weed competition, especially after their first year, and that nitrogen fertilization may alleviate effects of weeds on their growth. Poplars grown in sludge-amended soil did not accumulate more of any nutrient or heavy metal studied compared to those grown in nitrogen-fertilized soil. 17 refs., 5 figs., 57 tabs.

  7. Characterization of top phase oil obtained from co-pyrolysis of sewage sludge and poplar sawdust.

    PubMed

    Zuo, Wu; Jin, Baosheng; Huang, Yaji; Sun, Yu

    2014-01-01

    To research the impact of adding sawdust on top phase oil, a sewage sludge and poplar sawdust co-pyrolysis experiment was performed in a fixed bed. Gas chromatography (GC)/mass spectrometry (MS) was used to analyze the component distribution of top phase oil. Higher heating value, viscosity, water content, and pH of the top phase oil product were determined. The highest top phase oil yield (5.13 wt%) was obtained from the mixture containing 15% poplar sawdust, while the highest oil yield (16.51 wt%) was obtained from 20% poplar sawdust. Top phase oil collected from the 15% mixture also has the largest amount of aliphatics and the highest higher heating value (28.6 MJ/kg). Possible reaction pathways were proposed to explain the increase in the types of phenols present in the top phase oil as the proportion of poplar sawdust used in the mixture increased. It can be concluded that synergetic reactions occurred during co-pyrolysis of sewage sludge and poplar sawdust. The results indicate that the high ash content of the sewage sludge may be responsible for the characteristic change in the top phase oil obtained from the mixtures containing different proportions of sewage sludge and poplar sawdust. Consequently, co-pyrolysis of the mixture containing 15 % poplar sawdust can increase the yield and the higher heating value of top phase oil. PMID:24756683

  8. Enhancement of Biogas Yield of Poplar Leaf by High-Solid Codigestion with Swine Manure.

    PubMed

    Wangliang, Li; Zhikai, Zhang; Guangwen, Xu

    2016-05-01

    The aim of this work was to examine the improvement of anaerobic biodegradability of organic fractions of poplar leaf from codigestion with swine manure (SM), thus biogas yield and energy recovery. When poplar leaf was used as a sole substrate, the cumulative biogas yield was low, about 163 mL (g volatile solid (VS))(-1) after 45 days of digestion with a substrate/inoculum ratio of 2.5 and a total solid (TS) of 22 %. Under the same condition, the cumulative biogas yield of poplar leaf reached 321 mL (g VS)(-1) when SM/poplar leaf ratio was 2:5 (based on VS). The SM/poplar leaf ratio can determine C/N ratio of the cosubstrate and thus has significant influence on biogas yield. When the SM/poplar leaf ratio was 2:5, C/N ratio was calculated to be 27.02, and the biogas yield in 45 days of digestion was the highest. The semi-continuous digestion of poplar leaf was carried out with the organic loading rate of 1.25 and 1.88 g VS day(-1). The average daily biogas yield was 230.2 mL (g VS)(-1) and 208.4 mL (g VS)(-1). The composition analysis revealed that cellulose and hemicellulose contributed to the biogas production. PMID:26810922

  9. Major Chromosomal Rearrangements Distinguish Willow and Poplar After the Ancestral “Salicoid” Genome Duplication

    PubMed Central

    Hou, Jing; Ye, Ning; Dong, Zhongyuan; Lu, Mengzhu; Li, Laigeng; Yin, Tongming

    2016-01-01

    Populus (poplar) and Salix (willow) are sister genera in the Salicaceae family. In both lineages extant species are predominantly diploid. Genome analysis previously revealed that the two lineages originated from a common tetraploid ancestor. In this study, we conducted a syntenic comparison of the corresponding 19 chromosome members of the poplar and willow genomes. Our observations revealed that almost every chromosomal segment had a parallel paralogous segment elsewhere in the genomes, and the two lineages shared a similar syntenic pinwheel pattern for most of the chromosomes, which indicated that the two lineages diverged after the genome reorganization in the common progenitor. The pinwheel patterns showed distinct differences for two chromosome pairs in each lineage. Further analysis detected two major interchromosomal rearrangements that distinguished the karyotypes of willow and poplar. Chromosome I of willow was a conjunction of poplar chromosome XVI and the lower portion of poplar chromosome I, whereas willow chromosome XVI corresponded to the upper portion of poplar chromosome I. Scientists have suggested that Populus is evolutionarily more primitive than Salix. Therefore, we propose that, after the “salicoid” duplication event, fission and fusion of the ancestral chromosomes first give rise to the diploid progenitor of extant Populus species. During the evolutionary process, fission and fusion of poplar chromosomes I and XVI subsequently give rise to the progenitor of extant Salix species. This study contributes to an improved understanding of genome divergence after ancient genome duplication in closely related lineages of higher plants. PMID:27352946

  10. Phytoextraction of risk elements by willow and poplar trees.

    PubMed

    Kacálková, Lada; Tlustoš, Pavel; Száková, Jiřina

    2015-01-01

    To characterize the phytoextraction efficiency of two clones of willow trees (Salix x smithiana Willd., Salix rubens) and two clones of poplar trees (Populus nigra x maximowiczii, Populus nigra Wolterson) were planted in contaminated soil (0.4-2.0 mg Cd.kg(-1), 78-313 mg Zn.kg(-1), 21.3-118 mg Cu.kg(-1)). Field experiment was carried out in Czech Republic. The study investigated their ability to accumulate heavy metals (Cd, Zn, and Cu) in harvestable plant parts. The poplars produced higher amount of biomass than willows. Both Salix clones accumulated higher amount of Cd, Zn and Cu in their biomass (maximum 6.8 mg Cd.kg(-1), 909 mg Zn.kg(-1), and 17.7 mg Cu.kg(-1)) compared to Populus clones (maximum 2.06 mg Cd.kg(-1), 463 mg Zn.kg(-1), and 11.8 mg Cu.kg(-1)). There were no significant differences between clones of individual species. BCs for Cd and Zn were greater than 1 (the highest in willow leaves). BCs values of Cu were very low. These results indicate that Salix is more suitable plant for phytoextraction of Cd and Zn than Populus. The Cu phytoextraction potential of Salix and Populus trees was not confirmed in this experiment due to low soil availability of this element.

  11. Genetic transformation and expression of transgenic lines of Populus x euramericana with insect-resistance and salt-tolerance genes.

    PubMed

    Yang, R L; Wang, A X; Zhang, J; Dong, Y; Yang, M S; Wang, J M

    2016-01-01

    We characterized new transgenic varieties of poplar with multiple insect-resistant and salt stress tolerant genes. Two insect-resistant Bacillus thuringiensis (Bt) genes, Cry1Ac and Cry3A, and a salt-tolerant gene, Betaine aldehyde dehydrogenase (BADH) were inserted into a vector, p209-Cry1Ac-Cry3A-BADH. The clone of Populus x euramericana was transformed by the vector using the Agrobacterium-mediated method. Three transgenic lines were assessed using genetic detection and resistance expression analysis. PCR revealed that exogenous genes Cry1Ac, Cry3A, BADH and selective marker gene NPTII were present in three transgenic lines. Quantitative real-time PCR (qPCR) showed significant differences in the transcriptional abundance of three exogenous genes in different lines. Results of assays for Bt toxic proteins showed that the Cry1Ac and Cry3A toxic protein content of each line was 12.83-26.32 and 2108.91-2724.79 ng/g, respectively. The Cry1Ac toxic protein content of different lines was significantly different; the Cry3A toxic protein content was about 100 times higher than that of the Cry1Ac toxic protein. The insect-resistance test revealed the mortality rate of transgenic lines to Hyphantria cunea L1 larvae varied by 42.2-66.7%, which was significantly higher than non-transgenic lines. The mortality rate of L1 and L2 Plagiodera versicolora larvae was 100%. The insecticidal effect of transgenic lines to P. versicolora larvae was higher than that to H. cunea larvae. NaCl stress tolerance of three transgenic lines under 3-6% NaCl concentration was significantly higher than that of non-transgenic lines. PMID:27173305

  12. Transgenic algae engineered for higher performance

    SciTech Connect

    Unkefer, Pat J; Anderson, Penelope S; Knight, Thomas J

    2014-10-21

    The present disclosure relates to transgenic algae having increased growth characteristics, and methods of increasing growth characteristics of algae. In particular, the disclosure relates to transgenic algae comprising a glutamine phenylpyruvate transaminase transgene and to transgenic algae comprising a glutamine phenylpyruvate transaminase transgene and a glutamine synthetase.

  13. Soils organic C sequestration under poplar and willow agroforestry systems

    NASA Astrophysics Data System (ADS)

    Gunina, Anna; Tariq, Azeem; Lamersdorf, Norbert

    2015-04-01

    Short rotation coppices (SRC) as monocultures or as agroforestry (AF) applications (e.g. alley cropping) are two techniques to implement forest into agricultural practices. Despite afforestation promotes soil carbon (C) accumulation, age and type of the tree stand can affect the C accumulation in different degrees. Here, we studied the impact of afforestation on C accumulation for: i) pure SCR of willow (Salix viminalis x Salix schwerinii) and poplar (Populus nigra x Populus maximowiczii) and ii) AF cropping system with willow. Forest systems have been established within the BEST agroforestry project in Germany. Adjacent agricultural field have been used as a control. Soil samples were collected in 2014, three years after plantation establishment, from three soil depths: 0-3, 3-20, and 20-30 cm. Total organic C, labile C (incubation of 20 g soil during 100 days with measuring of CO2) and aggregate structure were analysed. Additionally, density fractionation of the samples from 0-3 cm was applied to separate particulate organic matter (POM) and mineral fractions. Aggregates and density fractions were analyzed for C content. High input of plant litter as well as root exudates have led to increases of organic C in AF and SRC plots compare to cropland, mainly in the top 0-3 cm. The highest C content was found for willow SRC (18.2 g kg-1 soil), followed by willow-AF (15.6 g kg-1 soil), and poplar SRC (13.7 g kg-1 soil). Carbon content of cropland was 12.5 g kg-1 soil. Absence of ploughing caused increase portion of macroaggregates (>2000 μm) under SRC and AF in all soil layers as well as the highest percentage of C in that aggregate size class (70-80%). In contrast, C in cropland soil was mainly accumulated in small macroaggregates (250-2000 μm). Intensive mineralisation of fresh litter and old POM, taking place during first years of trees development, resulted to similar portions of free POM for willow AF, willow SRC and cropland (8%), and even lower ones for poplar

  14. Cryopreservation of Xenopus transgenic lines.

    PubMed

    Buchholz, Daniel R; Fu, Liezhen; Shi, Yun-Bo

    2004-01-01

    Xenopus laevis has been widely used for molecular, cellular, and developmental studies. With the development of the sperm-mediated transgenic method, it is now possible to study gene function during vertebrate development by using this popular model. On the other hand, like other animal species, it is labor intensive, and the maintenance of transgenic lines is expensive. In this article, we investigated the possibility of using sperm-cryopreservation as a means to preserve transgenic frog lines. We demonstrated that cryopreserved sperms are viable but not fertile under our in vitro fertilization (IVF) conditions. However, by microinjecting cryopreserved sperm nuclei, we successfully regenerated a transgenic line carrying a double promoter transgene construct, where the marker gene encoding the green fluorescent protein (GFP) is driven by the gamma-crystallin gene promoter and a gene of interest, encoding a fusion protein of GFP with the matrix metalloproteinase stromelysin-3 (ST3-GFP), is driven by a heat shock-inducible promoter. We demonstrated the functional transmission of the ST3-GFP transgene by analyzing the phenotype of the F1 animals after heat-shock to induce its expression. Our method thus provides an inexpensive means to preserve transgenic frog lines and a convenient way for distribution of transgenic lines. Furthermore, the ease with which to microinject nuclei compared to the technically demanding transgenesis procedure with variable outcome should facilitate more laboratories to use transgenic Xenopus laevis for functional studies in vivo. Mol. Reprod. Dev. 67: 65-69, 2004.

  15. Comparisons of Ethanol Extracts of Chinese Propolis (Poplar Type) and Poplar Gums Based on the Antioxidant Activities and Molecular Mechanism

    PubMed Central

    Zhang, Jianglin; Cao, Xueping; Ping, Shun; Wang, Kai; Shi, Jinhu; Zhang, Cuiping; Zheng, Huoqing; Hu, Fuliang

    2015-01-01

    The biological activities of propolis are varied from plant sources and the prominent antioxidant effects of Chinese propolis (poplar type) have been extensively reported. Oxidative stress is associated with inflammation and induces many diseases. In the study, to evaluate antioxidant capacities and clarify the underlying molecular mechanisms of ethanol extracts of Chinese propolis (EECP) and ethanol extracts of poplar gums (EEPG), we analyzed their compositions by HPLC, evaluating their free radical scavenging activities and reducing power by chemical analysis methods. Moreover, we studied the roles of EECP and EEPG on the elimination of ROS and expressions of antioxidant genes (HO-1, TrxR1, GCLM, and GCLC) in RAW264.7 cells. We further investigated the effects of MAPKs on the antioxidant genes expression by specific inhibitors. The nucleus translocation effects of Nrf2 were also measured by confocal microscopy analysis. The results indicated that EECP had higher TPC and FDC values but regarding TFC values were not significant. EECP also possessed more contents of 11 compounds than EEPG. Both phytochemical analysis and cell experiment reflected that EECP exerted stronger antioxidant activities than EEPG. EECP and EEPG enhanced endogenous antioxidant defenses by eliminating reactive oxygen species directly and activating Erk-Nrf2-HO1, GCLM, and TrxR1 signal pathways. PMID:25802536

  16. Ethical issues in transgenics.

    PubMed

    Sherlock, R; Morrey, J D

    2000-01-01

    The arguments of critics and concerns of the public on generating transgenic cloned animals are analyzed for the absence or presence of logical structure. Critics' arguments are symbolically compared with "genetic trespassing," "genetic speeding," or "going the wrong way," and responses are provided to these arguments. Scientists will be empowered to participate in the public discussion and to engage the critics on these issues as they consider thoughtful, plausible responses to their concerns. Temporary moratoriums are recognized as a plausible approach to dealing with possible concerns of new scientific advancements.

  17. Landfill leachate treatment with willows and poplars--efficiency and plant response.

    PubMed

    Dimitriou, I; Aronsson, P

    2010-11-01

    Irrigation of willow and poplar short-rotation coppice with landfill leachate is an increasingly interesting treatment option. Minimal leaching to groundwater and disturbance to plant growth must be ensured, but in such systems, where various site-specific factors interact, a case-specific approach is needed to determine potential hazards. This paper compares the effect of leachate irrigation on willow grown in clay lysimeters and poplar grown in sand lysimeters. Leachate irrigation increased willow biomass production, but not that of poplar. Near-zero nitrate-N concentrations were found in drainage water for both species after 2 years of irrigation. Ability to retain total N and P, and TOC was relatively high for willow, taking into account the large amounts supplied, and better than for poplar. To reduce environmental risks the irrigation load should be reduced, but if leachate concentrations are reduced, the irrigation load can be as high as 6mm/day.

  18. Transgenic horticultural crops in Asia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modern biotechnology applications, including genetic engineering, are a powerful tool to complement the conventional methods of crop improvement. Asia currently has three countries cultivating biotech/transgenic crops – China, India, and the Philippines, but only China commercially grows a transgen...

  19. Stomatal factors and vulnerability of stem xylem to cavitation in poplars.

    PubMed

    Arango-Velez, Adriana; Zwiazek, Janusz J; Thomas, Barb R; Tyree, Melvin T

    2011-10-01

    The relationships between the vulnerability of stem xylem to cavitation, stomatal conductance, stomatal density, and leaf and stem water potential were examined in six hybrid poplar (P38P38, Walker, Okanese, Northwest, Assiniboine and Berlin) and balsam poplar (Populus balsamifera) clones. Stem xylem cavitation resistance was examined with the Cavitron technique in well-watered plants grown in the greenhouse. To investigate stomatal responses to drought, plants were subjected to drought stress by withholding watering for 5 (mild drought) and 7 (severe drought) days and to stress recovery by rewatering severely stressed plants for 30 min and 2 days. The clones varied in stomatal sensitivity to drought and vulnerability to stem xylem cavitation. P38P38 reduced stomatal conductance in response to mild stress while the balsam poplar clone maintained high leaf stomatal conductance under more severe drought stress conditions. Differences between the severely stressed clones were also observed in leaf water potentials with no or relatively small decreases in Assiniboine, P38P38, Okanese and Walker. Vulnerability to drought-induced stem xylem embolism revealed that balsam poplar and Northwest clones reached loss of conductivity at lower stem water potentials compared with the remaining clones. There was a strong link between stem xylem resistance to cavitation and stomatal responsiveness to drought stress in balsam poplar and P38P38. However, the differences in stomatal responsiveness to mild drought suggest that other drought-resistant strategies may also play a key role in some clones of poplars exposed to drought stress.

  20. Quantification of carbon sources for isoprene emission in poplar leaves

    NASA Astrophysics Data System (ADS)

    Kreutzwieseer, J.; Graus, M.; Schnitzler, J. P.; Heizmann, U.; Rennenberg, H.; Hansel, A.

    2003-12-01

    Isoprene is the most abundant volatile organic compound emitted by plants and in particular by trees. Current interest in understanding its biosynthesis in chloroplasts is forced by the important role isoprene plays in atmospheric chemistry. Leaf isoprene formation is closely linked to photosynthesis by a dynamic use of recently fixed photosynthetic precursors in the chloroplast. Under steady state conditions in [13C]CO2 atmosphere approximately 75 % of isoprene became labeled within minutes. The source of unlabeled C is suggested to be of extra-chloroplastidic and/or from starch degradation. In order to test whether these alternative carbon sources - leaf internal C-pools and xylem-transported carbohydrates, contribute to leaf isoprene formation in poplar (Populus tremula x P. alba) on-line proton-transfer-reaction-mass spectrometry (PTR-MS) was used to follow 13C-labeling kinetics.

  1. Analysis of 4,664 high-quality sequence-finished poplar full-length

    SciTech Connect

    Ralph, S.; Gunter, Lee E; Tuskan, Gerald A; Douglas, Carl; Holt, Robert A.; Jones, Steven; Marra, Marco; Bohlmann, J.

    2008-01-01

    The genus Populus includes poplars, aspens and cottonwoods, which will be collectively referred to as poplars hereafter unless otherwise specified. Poplars are the dominant tree species in many forest ecosystems in the Northern Hemisphere and are of substantial economic value in plantation forestry. Poplar has been established as a model system for genomics studies of growth, development, and adaptation of woody perennial plants including secondary xylem formation, dormancy, adaptation to local environments, and biotic interactions. As part of the poplar genome sequencing project and the development of genomic resources for poplar, we have generated a full-length (FL)-cDNA collection using the biotinylated CAP trapper method. We constructed four FLcDNA libraries using RNA from xylem, phloem and cambium, and green shoot tips and leaves from the P. trichocarpa Nisqually-1 genotype, as well as insect-attacked leaves of the P. trichocarpa x P. deltoides hybrid. Following careful selection of candidate cDNA clones, we used a combined strategy of paired end reads and primer walking to generate a set of 4,664 high-accuracy, sequence-verified FLcDNAs, which clustered into 3,990 putative unique genes. Mapping FLcDNAs to the poplar genome sequence combined with BLAST comparisons to previously predicted protein coding sequences in the poplar genome identified 39 FLcDNAs that likely localize to gaps in the current genome sequence assembly. Another 173 FLcDNAs mapped to the genome sequence but were not included among the previously predicted genes in the poplar genome. Comparative sequence analysis against Arabidopsis thaliana and other species in the non-redundant database of GenBank revealed that 11.5% of the poplar FLcDNAs display no significant sequence similarity to other plant proteins. By mapping the poplar FLcDNAs against transcriptome data previously obtained with a 15.5 K cDNA microarray, we identified 153 FLcDNA clones for genes that were differentially expressed in

  2. Green fluorescent protein as a tool for monitoring transgene expression in forest tree species.

    PubMed

    Tian, Lining; Levée, Valerie; Mentag, Rachid; Charest, Pierre J.; Séguin, Armand

    1999-07-01

    The gene coding for green fluorescent protein (GFP) from the jellyfish Aequorea victoria was successfully used as a vital marker for the transformation of three woody plant species, black spruce (Picea mariana (Mill.) BSP), white pine (Pinus strobus L.) and poplar (Populus spp.). The gfp gene and the gene conferring resistance to kanamycin (nptII) were introduced by microprojectile bombardment or Agrobacterium tumefaciens-mediated technology. Screening by fluorescence microscopy of the transformed plant material, under the selection of kanamycin, identified five to eight cell lines from each tree species that clearly expressed GFP. Expression of GFP was observed in somatic embryonal cells of the coniferous species and in stem sections of poplar. For all species, GFP transgene expression was stable over multiple subcultures. Stable integration of the gfp gene into plant genomes was confirmed by Southern hybridization or polymerase chain reaction (PCR) analysis. We conclude that GFP can be used as a vital marker and reporter protein in transformation experiments with gymnosperms and deciduous trees.

  3. Identification and Evaluation of Strain B37 of Bacillus subtilis Antagonistic to Sapstain Fungi on Poplar Wood

    PubMed Central

    Zhang, XiaoHua; Zhao, GuiHua; Li, DeWei; Li, ShunPeng; Hong, Qing

    2014-01-01

    Devaluation of poplar products by sapstain accounts for huge and unpredictable losses each year in China. We had isolated four poplar sapstain fungi, Ceratocystis adiposa Hz91, Lasiodiplodia theobromae YM0737, L. theobromae Fx46, and Fusarium sp. YM05, from five poplar varieties and 13 antagonistic bacteria from nine diverse varieties. After being experimented with agar plates, wood chips, and enzyme activities, strain B37 was identified as the best poplar sapstain biocontrol bacterium. The strain B37 was identified as Bacillus subtilis using sequences of the 16S rRNA gene, physiological biochemical, and morphological characteristics. PMID:25401124

  4. Identification and evaluation of strain B37 of Bacillus subtilis antagonistic to sapstain fungi on poplar wood.

    PubMed

    Zhang, XiaoHua; Zhao, GuiHua; Li, DeWei; Li, ShunPeng; Hong, Qing

    2014-01-01

    Devaluation of poplar products by sapstain accounts for huge and unpredictable losses each year in China. We had isolated four poplar sapstain fungi, Ceratocystis adiposa Hz91, Lasiodiplodia theobromae YM0737, L. theobromae Fx46, and Fusarium sp. YM05, from five poplar varieties and 13 antagonistic bacteria from nine diverse varieties. After being experimented with agar plates, wood chips, and enzyme activities, strain B37 was identified as the best poplar sapstain biocontrol bacterium. The strain B37 was identified as Bacillus subtilis using sequences of the 16S rRNA gene, physiological biochemical, and morphological characteristics. PMID:25401124

  5. [Transgenics without Manichaeism].

    PubMed

    Valle, S

    2000-01-01

    We live in an era characterized by the hegemony of science and technology, an era fraught with questions awaiting answers which would enable a safe and sustainable future for humankind. The development of agro-industrial processes - food products in particular - through recombinant DNA technology has enhanced the profit prospects of the few big biotechnology companies and of large-scale farmers who have access to the latest technological developments. We thus oppose a moratorium on recombinant DNA technology. Moreover, hasty statements about risk-free transgenics may be misleading in the absence of extensive safety tests. There is a pressing need for the establishment of biosafety policy in this country involving the organized civil society and every government agency responsible for monitoring such matters. There is also the need to put in place a bio-surveillance and a code of ethics regarding genetic manipulation.

  6. Control of trichome formation in Arabidopsis by poplar single-repeat R3 MYB transcription factors

    PubMed Central

    Zhou, Limei; Zheng, Kaijie; Wang, Xiaoyu; Tian, Hainan; Wang, Xianling; Wang, Shucai

    2014-01-01

    In Arabidopsis, trichome formation is regulated by the interplay of R3 MYBs and several others transcription factors including the WD40-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1), the R2R3 MYB transcription factor GLABRA1 (GL1), the bHLH transcription factor GLABRA3 (GL3) or ENHANCER OF GLABRA3 (EGL3), and the homeodomain protein GLABRA2 (GL2). R3 MYBs including TRICHOMELESS1 (TCL1), TCL2, TRYPTICHON (TRY), CAPRICE (CPC), ENHANCER OF TRY AND CPC1 (ETC1), ETC2 and ETC3 negatively regulate trichome formation by competing with GL1 for binding GL3 or EGL3, thus blocking the formation of TTG1–GL3/EGL3–GL1, an activator complex required for the activation of the trichome positive regulator gene GL2. However, it is largely unknown if R3 MYBs in other plant species especially woody plants have similar functions. By BLASTing the Populus trichocarpa protein database using the entire amino acid sequence of TCL1, an Arabidopsis R3 MYB transcription factor, we identified a total of eight R3 MYB transcription factor genes in poplar, namely P. trichocarpa TRICHOMELESS1 through 8 (PtrTCL1–PtrTCL8). The amino acid signature required for interacting with bHLH transcription factors and the amino acids required for cell-to-cell movement of R3 MYBs are not fully conserved in all PtrTCLs. When tested in Arabidopsis protoplasts, however, all PtrTCLs interacted with GL3. Expressing each of the eight PtrTCL genes in Arabidopsis resulted in either glabrous phenotypes or plants with reduced trichome numbers, and expression levels of GL2 in all transgenic plants tested were greatly reduced. Expression of PtrTCL1 under the control of TCL1 native promoter almost completely complemented the mutant phenotype of tcl. In contrast, expression of PtrTCL1 under the control of TRY native promoter in the try mutant, or under the control of CPC native promoter in the cpc mutant resulted in glabrous phenotypes, suggesting that PtrTCL1 functions similarly to TCL1, but not TRY and CPC. PMID

  7. Genome-wide analysis of a TaLEA-introduced transgenic Populus simonii × Populus nigra dwarf mutant.

    PubMed

    Yuan, Hong-Mei; Chen, Su; Lin, Lin; Wei, Rui; Li, Hui-Yu; Liu, Gui-Feng; Jiang, Jing

    2012-01-01

    A dwarf mutant (dwf1) was obtained among 15 transgenic lines, when TaLEA (Tamarix androssowii late embryogenesis abundant gene) was introduced into Populus simonii × Populus nigra by Agrobacterium tumefaciens-mediated transformation. Under the same growth conditions, dwf1 height was significantly reduced compared with the wild type and the other transgenic lines. Because only one transgenic line (dwf1) displayed the dwarf phenotype, we considered that T-DNA insertion sites may play a role in the mutant formation. The mechanisms underlying this effect were investigated using TAIL-PCR (thermal asymmetric interlaced PCR) and microarrays methods. According to the TAIL-PCR results, two flanking sequences located on chromosome IV and VIII respectively, were cloned. The results indicated the integration of two independent T-DNA copies. We searched for the potential genes near to the T-DNA insertions. The nearest gene was a putative poplar AP2 transcription factor (GI: 224073210). Expression analysis showed that AP2 was up-regulated in dwf1 compared with the wild type and the other transgenic lines. According to the microarrays results, a total of 537 genes involved in hydrolase, kinase and transcription factor activities, as well as protein and nucleotide binding, showed significant alterations in gene expression. These genes were expressed in more than 60 metabolic pathways, including starch, sucrose, galactose and glycerolipid metabolism and phenylpropanoids and flavonoid biosyntheses. Our transcriptome and T-DNA insertion sites analyses might provide some useful insights into the dwarf mutant formation. PMID:22489122

  8. Expression of wild-type PtrIAA14.1, a poplar Aux/IAA gene causes morphological changes in Arabidopsis

    PubMed Central

    Liu, Shanda; Hu, Qingnan; Luo, Sha; Li, Qianqian; Yang, Xiyu; Wang, Xianling; Wang, Shucai

    2015-01-01

    Aux/IAA proteins are transcriptional repressors that control auxin signaling by interacting with auxin response factors (ARFs). So far all of the identified Aux/IAA mutants with auxin-related phenotypes in Arabidopsis and rice (Oryza sativa) are dominant gain-of-function mutants, with mutations in Domain II that affected stability of the corresponding Aux/IAA proteins. On the other hand, morphological changes were observed in knock-down mutants of Aux/IAA genes in tomato (Solanum lycopersicum), suggesting that functions of Aux/IAA proteins may be specific for certain plant species. We report here the characterization of PtrIAA14.1, a poplar (Populus trichocarpa) homolog of IAA7. Bioinformatics analysis showed that PtrIAA14.1 is a classic Aux/IAA protein. It contains four conserved domains with the repressor motif in Domain I, the degron in Domain II, and the conserved amino acid signatures for protein–protein interactions in Domain III and Domain IV. Protoplast transfection assays showed that PtrIAA14.1 is localized in nucleus. It is unable in the presence of auxin, and it represses auxin response reporter gene expression. Expression of wild-type PtrIAA14.1 in Arabidopsis resulted in auxin-related phenotypes including down-curling leaves, semi-draft with increased number of branches, and greatly reduced fertility, but expression of the Arabidopsis Aux/IAA genes tested remain largely unchanged in the transgenic plants. Protein–protein interaction assays in yeast and protoplasts showed that PtrIAA14.1 interacted with ARF5, but not other ARFs. Consistent with this observation, vascular patterning was altered in the transgenic plants, and the expression of AtHB8 (Arabidopsis thaliana homeobox gene 8) was reduced in transgenic plants. PMID:26082787

  9. Contribution of temporal processing skills to reading comprehension in 8-year-olds: evidence for a mediation effect of phonological awareness.

    PubMed

    Malenfant, Nathalie; Grondin, Simon; Boivin, Michel; Forget-Dubois, Nadine; Robaey, Philippe; Dionne, Ginette

    2012-01-01

    This study tested whether the association between temporal processing (TP) and reading is mediated by phonological awareness (PA) in a normative sample of 615 eight-year-olds. TP was measured with auditory and bimodal (visual-auditory) temporal order judgment tasks and PA with a phoneme deletion task. PA partially mediated the association between both auditory and bimodal TP and reading, above nonverbal abilities, vocabulary, and processing speed. PA explained a larger proportion of the association between auditory TP and reading (56% vs. 39% for bimodal TP), and most of the association between bimodal TP and reading was direct. This finding is consistent with a dual-phonological and visual-pathway model of the association between TP and reading in normative reading skills.

  10. Assessing type a behavior in 8-year-olds: exploring the overlap between the constructs of type a behavior and hyperactivity.

    PubMed

    Eninger, L; Bohlin, G; Hagekull, B

    1997-01-01

    This study attempted to examine, by using behavioral observations, the overlap found between Type A behavior, as measured by the Matthews Youth Test for Health (MYTH) questionnaire, and measures of hyperactivity in children. The sample consisted of 91 children (46 boys and 45 girls) between the ages of 8 and 9 who were part of a longitudinal study in Uppsala, Sweden. Behavioral observations of Type A behavior and various questionnaire data were used. The behaviorally observed Type A behavior correlated significantly with MYTH Type A behavior, whereas only the MYTH Type A behavior correlated with hyperactivity measured by questionnaires. The results indicated that behavioral observations make it possible to measure Type A behavior as distinct from hyperactivity, implying that the MYTH is too indiscriminate a measure of Type A behavior. This has implications for future measurement and perhaps conceptualization of Type A behavior in children, and thereby also for studying the developmental aspects of Type A behavior. PMID:16250720

  11. Children's Teleological Intuitions: What Kind of Explanations Do 7-8 Year Olds Give for the Features of Organisms, Artifacts and Natural Objects?

    ERIC Educational Resources Information Center

    Kampourakis, Kostas; Pavlidi, Vasiliki; Papadopoulou, Maria; Palaiokrassa, Eirini

    2012-01-01

    Research has shown that children usually provide teleological explanations for the features of organisms from a very early age (3-4 years old). However, it is not clear if teleology is applied selectively for organisms, or if it is generally applied to other objects as well (artifacts and non-living natural objects). The present study examined…

  12. Persistence of antibodies in 4-8 year old Austrian children after vaccination with hexavalent DTaP-HBV-IPV/Hib and MMR vaccines.

    PubMed

    Paulke-Korinek, Maria; Fischmeister, Gustav; Grac, Ana; Rendi-Wagner, Pamela; Kundi, Michael; Mohsenzadeh-Rabbani, Afsaneh; Moritz, Katharina; Fenninger, Beate; Jarisch, Reinhart; Jasinska, Joanna; Holzmann, Heidemarie; Wiedermann, Ursula; Kollaritsch, Herwig

    2011-07-18

    To determine the proficiency of the Austrian childhood vaccination schedule to induce long lasting seroprotection against vaccine preventable diseases a seroepidemiological study in 348 children between four and eight years of age was conducted. Antibodies against diphtheria, tetanus, pertussis, hepatitis B, measles, mumps and rubella antigens were assessed in children, who had been vaccinated with hexavalent DTaP-HBV-IPV/Hib vaccines at three, four, five months and in the second year of life and/or MMR vaccines in the second year of life at least once, but mostly twice. High seroprotection rates (SPRs) were detected for tetanus (96%) and measles (90%). SPRs regarding diphtheria and mumps were 81% and 72%, respectively. Rubella-SPRs were 68% in females and 58% in males. Hepatitis B-antibody levels ≥10 mIU/mL were present in 52%; antibodies against pertussis were detected in 27% of the children. SPRs for measles and rubella depended on the interval since last vaccination; mumps-antibodies were significantly lower after one MMR-vaccination only. Antibodies against diphtheria, tetanus and pertussis depended on the interval since last vaccination while HBs-antibodies did not. The low levels of antibodies 1-7 years after vaccination against pertussis, rubella and mumps after only one vaccination should be considered when recommending new vaccination schedules.

  13. Retro- and prospection for mental time travel: emergence of episodic remembering and mental rotation in 5- to 8-year old children.

    PubMed

    Perner, Josef; Kloo, Daniela; Rohwer, Michael

    2010-09-01

    We investigate the common development of children's ability to "look back in time" (retrospection, episodic remembering) and to "look into the future" (prospection). Experiment 1 with 59 children 5 to 8.5 years old showed mental rotation, as a measure of prospection, explaining specific variance of free recall, as a measure of episodic remembering (retrospection) when controlled for cued recall. Experiment 2 with 31 children from 5 to 6.5 years measured episodic remembering with recall of visually experienced events (seeing which picture was placed inside a box) when controlling for recall of indirectly conveyed events (being informed about the pictures placed inside the box by showing the pictures on a monitor). Quite unexpectedly rotators were markedly worse on indirect items than non-rotators. We speculate that with the ability to rotate children switch from knowledge retrieval to episodic remembering, which maintains success for experienced events but has detrimental effects for indirect information. PMID:20650660

  14. Neural Correlates of Belief- and Desire-Reasoning in 7- and 8-Year-Old Children: An Event-Related Potential Study

    ERIC Educational Resources Information Center

    Bowman, Lindsay C.; Liu, David; Meltzoff, Andrew N.; Wellman, Henry M.

    2012-01-01

    Theory of mind requires belief- "and" desire-understanding. Event-related brain potential (ERP) research on belief- and desire-reasoning in adults found mid-frontal activations for both desires and beliefs, and selective right-posterior activations "only" for beliefs. Developmentally, children understand desires before beliefs; thus, a critical…

  15. [Significance of pregnancy and labor complications for the genesis of brain function disorders. Results of an epidemiologic study of 8-year-old children].

    PubMed

    Esser, G; Schmidt, M H

    1985-03-01

    An epidemiological and a clinical study were conducted to examine the importance of pregnancy and delivery complications in the genesis of cerebral dysfunction, the studies comprising a total of 495 children of 8 years of age. In the case definition of cerebral dysfunction, methodic improvements were used that had been demanded by those who had been critical of the clinical procedure. The results showed that clinical dysfunction is a risk factor for diseases in child psychiatry. There were no signs pointing to uniform psychopathological patterns (on the lines of a hyperkinetic syndrome) in children with cerebral dysfunction. There was no enhanced incidence of other diseases in the anamnesis of children with cerebral dysfunction. On the whole, the concept of cerebral dysfunction cannot be upheld at least to the extent presumed so far. A comparison between field study random samples and clinical study random samples showed that the classical postulates of the concept apply at most to a negligible minority only.

  16. Exploring the association between household food insecurity, parental self-efficacy, and fruit and vegetable parenting practices among parents of 5- to 8-year-old overweight children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food insecurity may negatively impact children’s nutritional status by affecting parenting quality. Because parents have a strong influence on their children’s eating and food choices, examining the effects of food insecurity on parenting may provide important insights into obesity prevention effort...

  17. Retro- and prospection for mental time travel: Emergence of episodic remembering and mental rotation in 5- to 8-year old children☆

    PubMed Central

    Perner, Josef; Kloo, Daniela; Rohwer, Michael

    2010-01-01

    We investigate the common development of children’s ability to “look back in time” (retrospection, episodic remembering) and to “look into the future” (prospection). Experiment 1 with 59 children 5 to 8.5 years old showed mental rotation, as a measure of prospection, explaining specific variance of free recall, as a measure of episodic remembering (retrospection) when controlled for cued recall. Experiment 2 with 31 children from 5 to 6.5 years measured episodic remembering with recall of visually experienced events (seeing which picture was placed inside a box) when controlling for recall of indirectly conveyed events (being informed about the pictures placed inside the box by showing the pictures on a monitor). Quite unexpectedly rotators were markedly worse on indirect items than non-rotators. We speculate that with the ability to rotate children switch from knowledge retrieval to episodic remembering, which maintains success for experienced events but has detrimental effects for indirect information. PMID:20650660

  18. Prevalence of DSM-IV disorders in a population-based sample of 5- to 8-year-old children: the impact of impairment criteria.

    PubMed

    Rijlaarsdam, Jolien; Stevens, Gonneke W J M; van der Ende, Jan; Hofman, Albert; Jaddoe, Vincent W V; Verhulst, Frank C; Tiemeier, Henning

    2015-11-01

    This study determined the impact of impairment criteria on the prevalence and patterns of comorbidity of child DSM-IV disorders. The validity of these impairment criteria was tested against different measures of mental health care referral and utilization. We interviewed parents of 1,154 children aged 5-8 years in-depth using the Diagnostic Interview Schedule for Children in Rotterdam, the Netherlands, to establish DSM-IV diagnosis. These children were randomly selected or oversampled based on Child Behavior Checklist ratings from a large population-based study (N = 6,172). Referral data were extracted from the psychiatric interview as well as from a follow-up questionnaire. The results showed an overall prevalence of DSM-IV disorders of 31.1 % when impairment was not considered. This rate declined to 22.9 % when mild impairment was required and declined even further, to 10.3 %, for more severe levels of impairment. Similarly, the overall comorbidity rate declined from 8.5 to 6.7 and 2.7 % when mild and severe impairment were required, respectively. Virtually all children who attained symptom thresholds for a specific disorder, and had been referred to a mental health care professional because of the associated symptoms, also had mild impairment. The requirement of severe impairment criteria significantly increased diagnostic thresholds, but for most disorders, this definition captured only half of the clinically referred cases. In conclusion, prevalence was highly dependent upon the criteria used to define impairment. If severe impairment is made a diagnostic requirement, many children with psychiatric symptoms and mild impairment seeking mental health care will be undiagnosed and possibly untreated.

  19. Development of a Theory-Based Internet Program Promoting Maintenance of Diet and Physical Activity Change to 8-Year-Old African American Girls

    ERIC Educational Resources Information Center

    Thompson, Debbe; Baranowski, Janice; Cullen, Karen; Baranowski, Tom

    2007-01-01

    Obesity and chronic disease risk factors are rising among youth. The Internet offers promise as a channel for delivering behavior change programs in a manner that is both available and accessible. This manuscript describes how theory informed the development of an Internet-based program promoting the maintenance of healthy eating and physical…

  20. Assessing type a behavior in 8-year-olds: exploring the overlap between the constructs of type a behavior and hyperactivity.

    PubMed

    Eninger, L; Bohlin, G; Hagekull, B

    1997-01-01

    This study attempted to examine, by using behavioral observations, the overlap found between Type A behavior, as measured by the Matthews Youth Test for Health (MYTH) questionnaire, and measures of hyperactivity in children. The sample consisted of 91 children (46 boys and 45 girls) between the ages of 8 and 9 who were part of a longitudinal study in Uppsala, Sweden. Behavioral observations of Type A behavior and various questionnaire data were used. The behaviorally observed Type A behavior correlated significantly with MYTH Type A behavior, whereas only the MYTH Type A behavior correlated with hyperactivity measured by questionnaires. The results indicated that behavioral observations make it possible to measure Type A behavior as distinct from hyperactivity, implying that the MYTH is too indiscriminate a measure of Type A behavior. This has implications for future measurement and perhaps conceptualization of Type A behavior in children, and thereby also for studying the developmental aspects of Type A behavior.

  1. The Children's Yale-Brown Obsessive Compulsive Scale: Reliability and Validity for Use among 5 to 8 Year Olds with Obsessive-Compulsive Disorder

    ERIC Educational Resources Information Center

    Freeman, Jennifer; Flessner, Christopher A.; Garcia, Abbe

    2011-01-01

    The Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) is the instrument of choice for assessing symptom severity in older children (i.e., 8-18 years) diagnosed with obsessive-compulsive disorder (OCD). The reliability and validity of this measure for use among younger children (i.e., 5-8 years of age), however, has never been examined.…

  2. Effectiveness of different tooth brushing techniques on the removal of dental plaque in 6–8 year old children of Gulbarga

    PubMed Central

    Patil, Smita P.; Patil, Prashant B.; Kashetty, Meena V.

    2014-01-01

    Objective: This study was undertaken to evaluate the respective effectiveness of the horizontal scrub, Fones, and modified Bass methods demonstrated on the cast to individual child within the classroom setting. Materials and Methods: A total of 180 healthy children studying in 1st and 2nd grades in the age range of 6-8 years were randomly selected from various schools of Gulbarga district, Karnataka, India. They were equally divided into three groups. Children in each group were demonstrated only one of the three brushing techniques, viz. horizontal scrub technique to group A, Fones technique to group B, and modified Bass technique to group C, using a cast model. All the children were re-examined and reviewed after 24 h and plaque index was re-assessed to obtain the follow-up data. The results were compared with the baseline data, and statistical analysis was carried out using paired t-test and intergroup comparison was made using analysis of variance (ANOVA) test. Results: Statistically significant (P < 0.001) reduction in plaque score was seen in modified Bass technique followed by horizontal scrub technique and the least efficacy was seen in Fones technique. Conclusion: This study showed that modified Bass technique was the most effective brushing technique in children. PMID:25254196

  3. Relationship between Special Abilities and Autistic-Like Traits in a Large Population-Based Sample of 8-Year-Olds

    ERIC Educational Resources Information Center

    Vital, Pedro M.; Ronald, Angelica; Wallace, Gregory L.; Happe, Francesca

    2009-01-01

    Background: The raised incidence of special abilities or "savant skills" among individuals with autism spectrum disorders (ASD) relative to other developmental disorders suggests an association between the traits characteristic of ASD and special abilities. The purpose of this study was to investigate the association between special abilities and…

  4. Micronutrient deficiencies are common in 6- to 8-year-old children of rural Nepal, with prevalence estimates modestly affected by inflammation.

    PubMed

    Schulze, Kerry J; Christian, Parul; Wu, Lee S F; Arguello, Margia; Cui, Hongjie; Nanayakkara-Bind, Ashika; Stewart, Christine P; Khatry, Subarna K; LeClerq, Steven; West, Keith P

    2014-06-01

    Subclinical micronutrient deficiencies remain a hidden aspect of malnutrition for which comprehensive data are lacking in school-aged children. We assessed the micronutrient status of Nepalese children, aged 6 to 8 y, born to mothers who participated in a community-based antenatal micronutrient supplementation trial from 1999 to 2001. Of 3305 participants, plasma indicators were assessed in a random sample of 1000 children. Results revealed deficiencies of vitamins A (retinol <0.70 μmol/L, 8.5%), D (25-hydroxyvitamin D <50 nmol/L, 17.2%), E (α-tocopherol <9.3 μmol/L, 17.9%), K (decarboxy prothombin >2 μg/L, 20%), B-12 (cobalamin <150 pmol/L, 18.1%), B-6 [pyridoxal-5'-phosphate (PLP) <20 nmol/L, 43.1%], and β-carotene (41.5% <0.09 μmol/L), with little folate deficiency (6.2% <13.6 nmol/L). Deficiencies of iron [ferritin <15 μg/L, 10.7%; transferrin receptor (TfR) >8.3 mg/L, 40.1%; TfR:ferritin >500 μg/μg, 14.3%], iodine (thyroglobulin >40 μg/L, 11.4%), and selenium (plasma selenium <0.89 μmol/L, 59.0%) were observed, whereas copper deficiency was nearly absent (plasma copper <11.8 μmol/L, 0.7%). Hemoglobin was not assessed. Among all children, 91.7% experienced at least 1 micronutrient deficiency, and 64.7% experienced multiple deficiencies. Inflammation (α-1 acid glycoprotein >1 g/L, C-reactive protein >5 mg/L, or both) was present in 31.6% of children, affecting the prevalence of deficiency as assessed by retinol, β-carotene, PLP, ferritin, TfR, selenium, copper, or having any or multiple deficiencies. For any nutrient, population deficiency prevalence estimates were altered by ≤5.4% by the presence of inflammation, suggesting that the majority of deficiencies exist regardless of inflammation. Multiple micronutrient deficiencies coexist in school-aged children in rural Nepal, meriting more comprehensive strategies for their assessment and prevention. PMID:24744314

  5. Contribution of Temporal Processing Skills to Reading Comprehension in 8-Year-Olds: Evidence for a Mediation Effect of Phonological Awareness

    ERIC Educational Resources Information Center

    Malenfant, Nathalie; Grondin, Simon; Boivin, Michel; Forget-Dubois, Nadine; Robaey, Philippe; Dionne, Ginette

    2012-01-01

    This study tested whether the association between temporal processing (TP) and reading is mediated by phonological awareness (PA) in a normative sample of 615 eight-year-olds. TP was measured with auditory and bimodal (visual-auditory) temporal order judgment tasks and PA with a phoneme deletion task. PA partially mediated the association between…

  6. Developing the IDEFICS Community-Based Intervention Program to Enhance Eating Behaviors in 2- to 8-Year-Old Children: Findings from Focus Groups with Children and Parents

    ERIC Educational Resources Information Center

    Haerens, L.; De Bourdeaudhuij, I.; Barba, G.; Eiben, G.; Fernandez, J.; Hebestreit, A.; Kovacs, E.; Lasn, H.; Regber, S.; Shiakou, M.; De Henauw, S.

    2009-01-01

    One purpose of "identification and prevention of dietary- and lifestyle-induced health effects in children and infants" (IDEFICS) is to implement a standardized community-based multi-component healthy eating intervention for younger children in eight different countries. The present study describes important influencing factors for dietary…

  7. Practical salinity management for leachate irrigation to poplar trees.

    PubMed

    Smesrud, Jason K; Duvendack, George D; Obereiner, James M; Jordahl, James L; Madison, Mark F

    2012-01-01

    Landfill leachate can be beneficially reused for irrigation of fiber crops with appropriate attention to nutrient and salinity management. The Riverbend Landfill in Western Oregon has been effectively practicing irrigation of landfill leachate to poplar trees since 1993. Over that time, the site has been adaptively managed to control salinity impacts to the tree crop while beneficially utilizing the applied water and nutrients during each growing season. Representative leachate irrigation water has ranged in concentration of total dissolved solids from 777 to 6,940 mg/L, chloride from 180 to 1,760 mg/L and boron from 3.2 to 7.3 mg/L. Annual leachate irrigation applications have also ranged between 102 and 812 mm/yr. Important conclusions from this site have included: 1) Appropriate tree clone selection and tree stand spacing, thinning, and harvest rotations are critical to maintaining a productive tree stand that is resilient and resistant to salt stress. The most effective combinations have included clones DN-34, OP-367, 184-411, 49-177, and 15-29 planted at spacing of 3.7-m x 1.8-m to 3.7-m x 3.7-m; 2) Leaf tissue boron levels are closely correlated to soil boron levels and can be managed with leaching. When leaf tissue boron levels exceed 200 to 250 mg/kg, signs of salt stress may emerge and should be monitored closely; 3) Salinity from leachate irrigation can be managed to sustain a healthy tree crop by controlling mass loading rates and providing appropriate irrigation blending if necessary. Providing freshwater irrigation following each leachate irrigation and targeting freshwater irrigation as 30 percent of total irrigation water applied has successfully controlled salt impacts to vegetation; and 4) Drip irrigation generally requires more careful attention to long-term soil salinity management than spray irrigation. Moving drip irrigation tubes periodically to prevent the formation of highly saline zones within the soil profile is important. In this paper, a

  8. Practical salinity management for leachate irrigation to poplar trees.

    PubMed

    Smesrud, Jason K; Duvendack, George D; Obereiner, James M; Jordahl, James L; Madison, Mark F

    2012-01-01

    Landfill leachate can be beneficially reused for irrigation of fiber crops with appropriate attention to nutrient and salinity management. The Riverbend Landfill in Western Oregon has been effectively practicing irrigation of landfill leachate to poplar trees since 1993. Over that time, the site has been adaptively managed to control salinity impacts to the tree crop while beneficially utilizing the applied water and nutrients during each growing season. Representative leachate irrigation water has ranged in concentration of total dissolved solids from 777 to 6,940 mg/L, chloride from 180 to 1,760 mg/L and boron from 3.2 to 7.3 mg/L. Annual leachate irrigation applications have also ranged between 102 and 812 mm/yr. Important conclusions from this site have included: 1) Appropriate tree clone selection and tree stand spacing, thinning, and harvest rotations are critical to maintaining a productive tree stand that is resilient and resistant to salt stress. The most effective combinations have included clones DN-34, OP-367, 184-411, 49-177, and 15-29 planted at spacing of 3.7-m x 1.8-m to 3.7-m x 3.7-m; 2) Leaf tissue boron levels are closely correlated to soil boron levels and can be managed with leaching. When leaf tissue boron levels exceed 200 to 250 mg/kg, signs of salt stress may emerge and should be monitored closely; 3) Salinity from leachate irrigation can be managed to sustain a healthy tree crop by controlling mass loading rates and providing appropriate irrigation blending if necessary. Providing freshwater irrigation following each leachate irrigation and targeting freshwater irrigation as 30 percent of total irrigation water applied has successfully controlled salt impacts to vegetation; and 4) Drip irrigation generally requires more careful attention to long-term soil salinity management than spray irrigation. Moving drip irrigation tubes periodically to prevent the formation of highly saline zones within the soil profile is important. In this paper, a

  9. Enantioselective Transport and Biotransformation of Chiral Hydroxylated Metabolites of Polychlorinated Biphenyls in Whole Poplar Plants

    PubMed Central

    2015-01-01

    Hydroxylated metabolites of polychlorinated biphenyls (OH-PCBs) have been found to be ubiquitous in the environment due to the oxidative metabolism of their parent PCBs. With more polarity, OH-PCBs may be more toxic and mobile than their parent compounds. However, the behavior and fate of OH-PCBs have been neglected in the environment because they are not the original contaminants. Some of these hydroxylated metabolites are chiral, and chiral compounds can be used to probe biological metabolic processes. Therefore, chiral OH-PCBs were selected to study their uptake, translocation, transformation, and enantioselectivity in plants in this work. Poplars (Populus deltoides × nigra, DN34), a model plant with complete genomic sequence, were hydroponically exposed to 5-hydroxy-2,2′,3,4′,6-pentachlorobiphenyl (5-OH-PCB91) and 5-hydroxy-2,2′,3,5′,6-pentachlorobiphenyl (5-OH-PCB95) for 10 days. Chiral 5-OH-PCB91 and 5-OH-PCB95 were clearly shown to be sorbed, taken up, and translocated in whole poplars, and they were detected in various tissues of whole poplars. However, the enantioselectivity of poplar for 5-OH-PCB91 and 5-OH-PCB95 proved to be quite different. The second-eluting enantiomer of OH-PCB95, separated on a chiral column (Phenomenex Lux Cellulose-1), was enantioselectively removed in whole poplar. Enantiomeric fractions in the middle xylem, top bark, top xylem, and stem, reached 0.803 ± 0.022, 0.643 ± 0.110, 0.835 ± 0.087, and 0.830 ± 0.029, respectively. Therefore, 5-OH-PCB95 was significantly enantioselectively biotransformed inside poplar tissues, in contrast to nearly racemic mixtures of 5-OH-PCB95 remaining in hydroponic solutions. Unlike 5-OH-PCB95, 5-OH-PCB91 remained nearly racemic in most tissues of whole poplars during 10 day exposure, suggesting the enantiomers of 5-OH-PCB91 were equally transported and metabolized in whole poplars. This is the first evidence of enantioselectivity of chiral OH-PCBs and suggests that poplars can

  10. Pharming and transgenic plants.

    PubMed

    Liénard, David; Sourrouille, Christophe; Gomord, Véronique; Faye, Loïc

    2007-01-01

    Plant represented the essence of pharmacopoeia until the beginning of the 19th century when plant-derived pharmaceuticals were partly supplanted by drugs produced by the industrial methods of chemical synthesis. In the last decades, genetic engineering has offered an alternative to chemical synthesis, using bacteria, yeasts and animal cells as factories for the production of therapeutic proteins. More recently, molecular farming has rapidly pushed towards plants among the major players in recombinant protein production systems. Indeed, therapeutic protein production is safe and extremely cost-effective in plants. Unlike microbial fermentation, plants are capable of carrying out post-translational modifications and, unlike production systems based on mammalian cell cultures, plants are devoid of human infective viruses and prions. Furthermore, a large panel of strategies and new plant expression systems are currently developed to improve the plant-made pharmaceutical's yields and quality. Recent advances in the control of post-translational maturations in transgenic plants will allow them, in the near future, to perform human-like maturations on recombinant proteins and, hence, make plant expression systems suitable alternatives to animal cell factories.

  11. Pharming and transgenic plants.

    PubMed

    Liénard, David; Sourrouille, Christophe; Gomord, Véronique; Faye, Loïc

    2007-01-01

    Plant represented the essence of pharmacopoeia until the beginning of the 19th century when plant-derived pharmaceuticals were partly supplanted by drugs produced by the industrial methods of chemical synthesis. In the last decades, genetic engineering has offered an alternative to chemical synthesis, using bacteria, yeasts and animal cells as factories for the production of therapeutic proteins. More recently, molecular farming has rapidly pushed towards plants among the major players in recombinant protein production systems. Indeed, therapeutic protein production is safe and extremely cost-effective in plants. Unlike microbial fermentation, plants are capable of carrying out post-translational modifications and, unlike production systems based on mammalian cell cultures, plants are devoid of human infective viruses and prions. Furthermore, a large panel of strategies and new plant expression systems are currently developed to improve the plant-made pharmaceutical's yields and quality. Recent advances in the control of post-translational maturations in transgenic plants will allow them, in the near future, to perform human-like maturations on recombinant proteins and, hence, make plant expression systems suitable alternatives to animal cell factories. PMID:17875476

  12. Poplar-Root Knot Nematode Interaction: A Model for Perennial Woody Species.

    PubMed

    Baldacci-Cresp, Fabien; Sacré, Pierre-Yves; Twyffels, Laure; Mol, Adeline; Vermeersch, Marjorie; Ziemons, Eric; Hubert, Philippe; Pérez-Morga, David; El Jaziri, Mondher; de Almeida Engler, Janice; Baucher, Marie

    2016-07-01

    Plant root-knot nematode (RKN) interaction studies are performed on several host plant models. Though RKN interact with trees, no perennial woody model has been explored so far. Here, we show that poplar (Populus tremula × P. alba) grown in vitro is susceptible to Meloidogyne incognita, allowing this nematode to penetrate, to induce feeding sites, and to successfully complete its life cycle. Quantitative reverse transcription-polymerase chain reaction analysis was performed to study changes in poplar gene expression in galls compared with noninfected roots. Three genes (expansin A, histone 3.1, and asparagine synthase), selected as gall development marker genes, followed, during poplar-nematode interaction, a similar expression pattern to what was described for other plant hosts. Downregulation of four genes implicated in the monolignol biosynthesis pathway was evidenced in galls, suggesting a shift in the phenolic profile within galls developed on poplar roots. Raman microspectroscopy demonstrated that cell walls of giant cells were not lignified but mainly composed of pectin and cellulose. The data presented here suggest that RKN exercise conserved strategies to reproduce and to invade perennial plant species and that poplar is a suitable model host to study specific traits of tree-nematode interactions. PMID:27135257

  13. [Canopy conductance characteristics of poplar in agroforestry system in west Liaoning Province of Northeast China].

    PubMed

    Li, Zheng; Niu, Li-Hua; Yuan, Feng-Hui; Guan, De-Xin; Wang, An-Zhi; Jin, Chang-Jie; Wu, Jia-Bing

    2012-11-01

    By using Granier' s thermal dissipation probe, the sap flow of poplar in a poplar-maize agroforestry system in west Liaoning was continuously measured, and as well, the environmental factors such as air temperature, air humidity, net radiation, wind speed, soil temperature, and soil moisture content were synchronically measured. Based on the sap flow data, the canopy conductance of poplar was calculated with simplified Penman-Monteith equation. In the study area, the diurnal variation of poplar' s canopy conductance showed a "single peak" curve, whereas the seasonal variation showed a decreasing trend. There was a negative logarithm relationship between the canopy conductance and vapor pressure deficit, with the sensitivity of canopy conductance to vapor pressure deficit change decreased gradually from May to September. The canopy conductance had a positive relationship with solar radiation. In different months, the correlation degree of canopy conductance with environmental factors differed. The vapor pressure deficit in the whole growth period of poplar was the most significant environmental factor correlated with the canopy conductance. PMID:23431778

  14. Transcriptome Analysis of Poplar during Leaf Spot Infection with Sphaerulina spp.

    PubMed

    Foster, Adam J; Pelletier, Gervais; Tanguay, Philippe; Séguin, Armand

    2015-01-01

    Diseases of poplar caused by the native fungal pathogen Sphaerulina musiva and related species are of growing concern, particularly with the increasing interest in intensive poplar plantations to meet growing energy demands. Sphaerulina musiva is able to cause infection on leaves, resulting in defoliation and canker formation on stems. To gain a greater understanding of the different responses of poplar species to infection caused by the naturally co-evolved Sphaerulina species, RNA-seq was conducted on leaves of Populus deltoides, P. balsamifera and P. tremuloides infected with S. musiva, S. populicola and a new undescribed species, Ston1, respectively. The experiment was designed to contain the pathogen in a laboratory environment, while replicating disease development in commercial plantations. Following inoculation, trees were monitored for disease symptoms, pathogen growth and host responses. Genes involved in phenylpropanoid, terpenoid and flavonoid biosynthesis were generally upregulated in P. balsamifera and P. tremuloides, while cell wall modification appears to play an important role in the defense of P. deltoides. Poplar defensive genes were expressed early in P. balsamifera and P. tremuloides, but their expression was delayed in P. deltoides, which correlated with the rate of disease symptoms development. Also, severe infection in P. balsamifera led to leaf abscission. This data gives an insight into the large differences in timing and expression of genes between poplar species being attacked by their associated Sphaerulina pathogen.

  15. [Canopy conductance characteristics of poplar in agroforestry system in west Liaoning Province of Northeast China].

    PubMed

    Li, Zheng; Niu, Li-Hua; Yuan, Feng-Hui; Guan, De-Xin; Wang, An-Zhi; Jin, Chang-Jie; Wu, Jia-Bing

    2012-11-01

    By using Granier' s thermal dissipation probe, the sap flow of poplar in a poplar-maize agroforestry system in west Liaoning was continuously measured, and as well, the environmental factors such as air temperature, air humidity, net radiation, wind speed, soil temperature, and soil moisture content were synchronically measured. Based on the sap flow data, the canopy conductance of poplar was calculated with simplified Penman-Monteith equation. In the study area, the diurnal variation of poplar' s canopy conductance showed a "single peak" curve, whereas the seasonal variation showed a decreasing trend. There was a negative logarithm relationship between the canopy conductance and vapor pressure deficit, with the sensitivity of canopy conductance to vapor pressure deficit change decreased gradually from May to September. The canopy conductance had a positive relationship with solar radiation. In different months, the correlation degree of canopy conductance with environmental factors differed. The vapor pressure deficit in the whole growth period of poplar was the most significant environmental factor correlated with the canopy conductance.

  16. Evapotranspiration and crop coefficient of poplar and willow short-rotation coppice used as vegetation filter.

    PubMed

    Guidi, Werther; Piccioni, Emiliano; Bonari, Enrico

    2008-07-01

    Ten-day evapotranspiration (ETc) and crop coefficient (k(c)) of willow and poplar SRC used as vegetation filter and grown under fertilised (F) and unfertilised (NF) conditions, were determined for two successive growing seasons using volumetric lysimeters. During the first growing season, total ETc observed was, respectively, 620 (NF)-1190 (F)mm in willow and 590 (NF)-725 (F) in poplar. During the second growing season, ETc showed a general increase, mainly in fertilised lysimeters where it ranged between 890 (NF)-1790 mm (F) in willow and 710 (NF)-1100 mm (NF) in poplar. kc reached in both years its maximum between the end of August and the beginning of September. In 2004 maximum kc ranged from 1.25-2.84 in willow and 1.06-1.90 in poplar, whereas in 2005 it ranged from 1.97-5.30 in willow and 1.71-4.28 in poplar. ETc seemed to be strongly correlated to plant development and mainly dependent on its nutritional status rather than on the differences between the species.

  17. Genetic variation of hydraulic and wood anatomical traits in hybrid poplar and trembling aspen.

    PubMed

    Schreiber, Stefan G; Hacke, Uwe G; Hamann, Andreas; Thomas, Barb R

    2011-04-01

    Intensive forestry systems and breeding programs often include either native aspen or hybrid poplar clones, and performance and trait evaluations are mostly made within these two groups. Here, we assessed how traits with potential adaptive value varied within and across these two plant groups. Variation in nine hydraulic and wood anatomical traits as well as growth were measured in selected aspen and hybrid poplar genotypes grown at a boreal planting site in Alberta, Canada. Variability in these traits was statistically evaluated based on a blocked experimental design. We found that genotypes of trembling aspen were more resistant to cavitation, exhibited more negative water potentials, and were more water-use-efficient than hybrid poplars. Under the boreal field test conditions, which included major regional droughts, height growth was negatively correlated with branch vessel diameter (Dv ) in both aspen and hybrid poplars and differences in Dv were highly conserved in aspen trees from different provenances. Differences between the hybrid poplars and aspen provenances suggest that these two groups employ different water-use strategies. The data also suggest that vessel diameter may be a key trait in evaluating growth performance in a boreal environment.

  18. Ecological risk assessment of the fish community of the Clinch River/Poplar Creek system

    SciTech Connect

    Suter, G.; Barnthouse, L.; Efroymson, R.; Jaeger, H.; Beauchamp, J.

    1995-12-31

    The CERCLA remedial investigation for the Clinch River/Poplar Creek included the fish community as an endpoint. The assessment endpoint was defined as a 20% reduction in the species richness or abundance of the fish community in the Poplar Creek embayment or in any of three reaches of the Clinch River. Screening of chemicals in water against benchmarks determined that Ag, Cd, Cu, Hg, Ni, Zn, PCBs, and bis(2-ethylhexyl)phthalate were contaminants of potential ecological concern (COPECs). Comparison of the distributions of COPEC concentrations with the distributions of literature toxicity values indicated that none of the COPECs was routinely toxic but episodic concentrations (< 10% of the distribution) of some COPECs were in the toxic range. Aqueous toxicity tests gave unclear results except for regularly high lethality to fish embryos in Poplar Creek. Bioindicators analysis found elevated histopathologies and disrupted reproductive indicators in Centrarchids from Poplar Creek, but their implications for the community are unclear. Body burdens of PCBs in some channel catfish exceeded levels associated with sublethal effects on that species in the laboratory. Electrofishing and gill netting found that the fish community of Poplar Creek had low species number and abundance, but habitat quality was also low. These mixed results present a challenge to ecological risk characterization based on weight-of-evidence. The process of weighing the evidence will be presented.

  19. Poplar-Root Knot Nematode Interaction: A Model for Perennial Woody Species.

    PubMed

    Baldacci-Cresp, Fabien; Sacré, Pierre-Yves; Twyffels, Laure; Mol, Adeline; Vermeersch, Marjorie; Ziemons, Eric; Hubert, Philippe; Pérez-Morga, David; El Jaziri, Mondher; de Almeida Engler, Janice; Baucher, Marie

    2016-07-01

    Plant root-knot nematode (RKN) interaction studies are performed on several host plant models. Though RKN interact with trees, no perennial woody model has been explored so far. Here, we show that poplar (Populus tremula × P. alba) grown in vitro is susceptible to Meloidogyne incognita, allowing this nematode to penetrate, to induce feeding sites, and to successfully complete its life cycle. Quantitative reverse transcription-polymerase chain reaction analysis was performed to study changes in poplar gene expression in galls compared with noninfected roots. Three genes (expansin A, histone 3.1, and asparagine synthase), selected as gall development marker genes, followed, during poplar-nematode interaction, a similar expression pattern to what was described for other plant hosts. Downregulation of four genes implicated in the monolignol biosynthesis pathway was evidenced in galls, suggesting a shift in the phenolic profile within galls developed on poplar roots. Raman microspectroscopy demonstrated that cell walls of giant cells were not lignified but mainly composed of pectin and cellulose. The data presented here suggest that RKN exercise conserved strategies to reproduce and to invade perennial plant species and that poplar is a suitable model host to study specific traits of tree-nematode interactions.

  20. Transcriptome Analysis of Poplar during Leaf Spot Infection with Sphaerulina spp.

    PubMed Central

    Foster, Adam J.; Pelletier, Gervais; Tanguay, Philippe; Séguin, Armand

    2015-01-01

    Diseases of poplar caused by the native fungal pathogen Sphaerulina musiva and related species are of growing concern, particularly with the increasing interest in intensive poplar plantations to meet growing energy demands. Sphaerulina musiva is able to cause infection on leaves, resulting in defoliation and canker formation on stems. To gain a greater understanding of the different responses of poplar species to infection caused by the naturally co-evolved Sphaerulina species, RNA-seq was conducted on leaves of Populus deltoides, P. balsamifera and P. tremuloides infected with S. musiva, S. populicola and a new undescribed species, Ston1, respectively. The experiment was designed to contain the pathogen in a laboratory environment, while replicating disease development in commercial plantations. Following inoculation, trees were monitored for disease symptoms, pathogen growth and host responses. Genes involved in phenylpropanoid, terpenoid and flavonoid biosynthesis were generally upregulated in P. balsamifera and P. tremuloides, while cell wall modification appears to play an important role in the defense of P. deltoides. Poplar defensive genes were expressed early in P. balsamifera and P. tremuloides, but their expression was delayed in P. deltoides, which correlated with the rate of disease symptoms development. Also, severe infection in P. balsamifera led to leaf abscission. This data gives an insight into the large differences in timing and expression of genes between poplar species being attacked by their associated Sphaerulina pathogen. PMID:26378446

  1. Enhanced ethanol production from deacetylated yellow poplar acid hydrolysate by Pichia stipitis.

    PubMed

    Cho, Dae Haeng; Shin, Soo-Jeong; Bae, Yangwon; Park, Chulhwan; Kim, Yong Hwan

    2010-07-01

    In this study, alkaline-pretreatment for the extraction of acetic acid from xylan of hemicellulose was introduced prior to concentrated acid hydrolysis of yellow poplar wood meal. Ethanol fermentability in deacetylated yellow poplar hydrolysate (DYPH) by Pichia stipitis was also investigated. The alkali-pretreatment conditions were evaluated in terms of temperature, reaction time, and alkalinity. 94% of the acetyl group in xylan of the yellow poplar hemicellulose fraction was extracted using 0.5% sodium hydroxide solution at 60 degrees C for 60 min. The cell growth and ethanol production of P. stipitis was strongly affected by acetic acid, either in synthetic medium with 7.1g/l of acetic acid added or in yellow poplar hydrolysate (YPH) containing 7.1g/l of acetic acid. On the other hand, ethanol production in DYPH was slightly higher than that of the control although cell growth decreased by 34%. In the case of DYPH, the ethanol yield, volumetric ethanol productivity, and theoretical yield percentage was 0.48 g/g, 0.40 g/lh, and 93.2%, respectively. Thus, the alkaline-pretreatment method greatly enhanced the ethanol fermentability of yellow poplar hydrolysate. PMID:19959357

  2. Field note: hydraulic containment of a BTEX plume using poplar trees.

    PubMed

    Barac, Tanja; Weyens, Nele; Oeyen, Licy; Taghavi, Safiyh; van der Lelie, Daniel; Dubin, Dirk; Spliet, Marco; Vangronsveld, Jaco

    2009-07-01

    In 1999, 275 poplar trees were planted on a field site near a car factory in order to install a bioscreen. The aim was to combine the biodegradation activities of poplar and its associated rhizosphere and endophytic microorganisms for containing a BTEX contaminated groundwater plume. This BTEX plume occurred as the result of leaking solvents and fuel storage tanks. Monitoring, conducted overa 6-year period (1999-2005) after the planting of the trees suggested that the poplar trees and their associated microorganisms had, once the tree roots reached the contaminated groundwater zone, an active role in the remediation of the BTEX plume, resulting in full containment of the contamination. Analysis of the microbial communities associated with poplar demonstrated that, once the poplar roots got in contact with the BTEX contaminated groundwater, enrichment occurred of both rhizosphere and endophytic bacteria that were able to degrade toluene. Interestingly, once the BTEX plume was remediated, the numbers of toluene degrading rhizosphere and endophytic bacteria decreased below the detection limit, indicating that their population resulted from selective enrichment by the presence of the contaminants.

  3. Sorption, uptake, and biotransformation of 17β-estradiol, 17α-ethinylestradiol, zeranol, and trenbolone acetate by hybrid poplar.

    PubMed

    Bircher, Sam; Card, Marcella L; Zhai, Guangshu; Chin, Yu-Ping; Schnoor, Jerald L

    2015-12-01

    Hormonally active compounds may move with agricultural runoff from fields with applied manure and biosolids into surface waters where they pose a threat to human and environmental health. Riparian zone plants could remove hormonally active compounds from agricultural runoff. Therefore, sorption to roots, uptake, translocation, and transformation of 3 estrogens (17β-estradiol, 17α-ethinylestradiol, and zeranol) and 1 androgen (trenbolone acetate) commonly found in animal manure or biosolids were assessed by hydroponically grown hybrid poplar, Populus deltoides x nigra, DN-34, widely used in riparian buffer strips. Results clearly showed that these hormones were rapidly removed from 2 mg L(-1) hydroponic solutions by more than 97% after 10 d of exposure to full poplar plants or live excised poplars (cut-stem, no leaves). Removals by sorption to dead poplar roots that had been autoclaved were significantly less, 71% to 84%. Major transformation products (estrone and estriol for estradiol; zearalanone for zeranol; and 17β-trenbolone from trenbolone acetate) were detected in the root tissues of all 3 poplar treatments. Root concentrations of metabolites peaked after 1 d to 5 d and then decreased in full and live excised poplars by further transformation. Metabolite concentrations were less in dead poplar treatments and only slowly increased without further transformation. Taken together, these findings show that poplars may be effective in controlling the movement of hormonally active compounds from agricultural fields and avoiding runoff to streams.

  4. Sorption, uptake, and biotransformation of 17β-estradiol, 17α-ethinylestradiol, zeranol, and trenbolone acetate by hybrid poplar.

    PubMed

    Bircher, Sam; Card, Marcella L; Zhai, Guangshu; Chin, Yu-Ping; Schnoor, Jerald L

    2015-12-01

    Hormonally active compounds may move with agricultural runoff from fields with applied manure and biosolids into surface waters where they pose a threat to human and environmental health. Riparian zone plants could remove hormonally active compounds from agricultural runoff. Therefore, sorption to roots, uptake, translocation, and transformation of 3 estrogens (17β-estradiol, 17α-ethinylestradiol, and zeranol) and 1 androgen (trenbolone acetate) commonly found in animal manure or biosolids were assessed by hydroponically grown hybrid poplar, Populus deltoides x nigra, DN-34, widely used in riparian buffer strips. Results clearly showed that these hormones were rapidly removed from 2 mg L(-1) hydroponic solutions by more than 97% after 10 d of exposure to full poplar plants or live excised poplars (cut-stem, no leaves). Removals by sorption to dead poplar roots that had been autoclaved were significantly less, 71% to 84%. Major transformation products (estrone and estriol for estradiol; zearalanone for zeranol; and 17β-trenbolone from trenbolone acetate) were detected in the root tissues of all 3 poplar treatments. Root concentrations of metabolites peaked after 1 d to 5 d and then decreased in full and live excised poplars by further transformation. Metabolite concentrations were less in dead poplar treatments and only slowly increased without further transformation. Taken together, these findings show that poplars may be effective in controlling the movement of hormonally active compounds from agricultural fields and avoiding runoff to streams. PMID:26184466

  5. Transgenic hepatocarcinogenesis in the rat.

    PubMed Central

    Hully, J. R.; Su, Y.; Lohse, J. K.; Griep, A. E.; Sattler, C. A.; Haas, M. J.; Dragan, Y.; Peterson, J.; Neveu, M.; Pitot, H. C.

    1994-01-01

    Although transgenic hepatocarcinogenesis has been accomplished in the mouse with a number of genetic constructs targeting the oncogene to expression primarily in the liver, no example of this process has yet been developed in the rat. Because our understanding of the multistage nature of hepatocarcinogenesis is most advanced in the rat, we have developed a strain of transgenic rats carrying the promoter-enhancer sequences of the mouse albumin gene linked 5' to the simian virus-40 T antigen gene. A line of transgenic rats bearing this transgene has been developed from a single founder female. Five to six copies of the transgene, possibly in tandem, occur within the genome of the transgenic animals, which are maintained by heterozygous matings. Livers of transgenic animals are histologically normal after weaning; at 2 months of age, small foci of vacuolated cells appear in this organ. By 4 months of age, all animals exhibit focal lesions and nodules consisting primarily of small basophilic cells, many of which exhibit considerable cytoplasmic vacuolization. Mating of animals each bearing the transgene results in rats with a demyelinating condition that develops acutely in pregnant females and more chronically in males. Ultrastructural studies of these cells indicate that the vacuoles contain substantial amounts of glycogen, with the cells resembling hepatoblasts. Malignant neoplasms with both a glandular and a hepatoblastoma/hepatocellular carcinoma pattern arise from the nodules. Enzyme and immunohistochemical studies of all lesions reveal many similarities in gene expression to comparable lesions in rats subjected to chemically induced hepatocarcinogenesis, with certain exceptions. The placental form of glutathione-S-transferase is absent from all lesions in the transgenic animal, as is the expression of connexin 32. A significant number of lesions express serum albumin, and many, but not all, exhibit the T antigen. Lesions expressing the T antigen also contain

  6. Cadmium interferes with auxin physiology and lignification in poplar

    PubMed Central

    Elobeid, Mudawi; Göbel, Cornelia; Feussner, Ivo; Polle, Andrea

    2012-01-01

    Cadmium (Cd) is a phytotoxic heavy metal that causes rapid growth reduction. To investigate if Cd interferes with the metabolism of auxin, a major growth hormone in plants, poplars (Populus×canescens) expressing a heterologous GH3::GUS reporter gene were exposed to 50 μM Cd in hydroponic solutions. Growth, photosynthetic performance, lignification, peroxidase activity, auxin concentration, and GUS staining were determined in order to record the activities of GH3 enzymes in the stem apex, the elongation zone, wood in the zone of radial growth, and in roots. Cd-induced growth reductions were tissue-specific decreasing in the order: roots>wood>shoot elongation and leaf initiation, whereas Cd concentrations increased in the order: leaves

  7. BIOLOGICAL MONITORING PROGRAM FOR EAST FORK POPLAR CREEK

    SciTech Connect

    ADAMS, S.M.; ASHWOOD, T.L.; BEATY, T.W.; BRANDT, C.C.

    1997-10-24

    In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y- 12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the complex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity of EFPC. These tasks are (1) toxicity monitoring, (2) biological indicator studies, (3) bioaccumulation studies, and (4) ecological surveys of the periphyton, benthic macroinvertebrate, and fish communities.

  8. Enhanced vadose zone nitrogen removal by poplar during dormancy.

    PubMed

    Ausland, Hayden; Ward, Adam; Licht, Louis; Just, Craig

    2015-01-01

    A pilot-scale, engineered poplar tree vadose zone system was utilized to determine effluent nitrate (NO3(-)) and ammonium concentrations resulting from intermittent dosing of a synthetic wastewater onto sandy soils at 4.5°C. The synthetic wastewater replicated that of an industrial food processor that irrigates onto sandy soils even during dormancy which can leave groundwater vulnerable to NO3(-) contamination. Data from a 21-day experiment was used to assess various Hydrus model parameterizations that simulated the impact of dormant roots. Bromide tracer data indicated that roots impacted the hydraulic properties of the packed sand by increasing effective dispersion, water content and residence time. The simulated effluent NO3(-) concentration on day 21 was 1.2 mg-N L(-1) in the rooted treatments compared to a measured value of 1.0 ± 0.72 mg-N L(-1). For the non-rooted treatment, the simulated NO3(-) concentration was 4.7 mg-N L(-1) compared to 5.1 ± 3.5 mg-N L(-1) measured on day 21. The model predicted a substantial "root benefit" toward protecting groundwater through increased denitrification in rooted treatments during a 21-day simulation with 8% of dosed nitrogen converted to N2 compared to 3.3% converted in the non-rooted test cells. Simulations at the 90-day timescale provided similar results, indicating increased denitrification in rooted treatments.

  9. Biomass and nitrogen dynamics in an irrigated hybrid poplar plantation

    SciTech Connect

    McLaughlin, R.A.

    1985-01-01

    A 3-year study measured the effects of ground cover treatments and nitrogen fertilization on biomass and nitrogen dynamics in an irrigated hybrid poplar (Populus deltoides Bartr. x P. trichocarpa Torr. and Gray, clone NC-9922) plantation in northern Wisconsin. Annually fertilized (112 kg N/ha/yr) and unfertilized plots were either maintained weed-free (bare soil), allowed to revegetate with native weeds, or seeded to birdsfoot trefoil (Lotus corniculatus L.). Trees in bare soil plots responded to fertilization primarily in the third growing season, but total biomass of 3-year-old trees was not increased by annual fertilization. High nitrate-nitrogen concentrations in the soil solution suggested significant leaching in both unfertilized and fertilized bare soil plots in the first growing season, and in fertilized plots the second season. Nitrate-nitrogen concentrations declined sharply in fertilized bare soil plots during the third growing season. Cover crop biomass was greatest in the second year and declined thereafter due to declines in below-ground components. Fertilization increased tree growth in these plots, but cover crop treatments had no effect. Results of this study suggest that, under irrigated conditions, a cover crop can substantially reduce leaching losses of nutrients and serve as a slow-release pool of nitrogen after the trees achieve crown closure. Fertilization is not recommended in these plantations until the second growing season if a cover crop is present and the third growing season if complete weed control is practiced.

  10. BIOLOGICAL MONITORING PROGRAM FOR EAST FORK POPLAR CREEK

    SciTech Connect

    ADAMS, S.M.; BEATY, T.W.; BRANDT, C.C.; CHRISTENSEN, S.W.; CICERONE, D.S.

    1998-09-09

    In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the complex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity of EFPC. These tasks are (1) toxicity monitoring, (2) biological indicator studies, (3) bioaccumulation studies, and (4) ecological surveys of the periphyton, benthic macroinvertebrate, and fish communities.

  11. Dual targeted poplar ferredoxin NADP(+) oxidoreductase interacts with hemoglobin 1.

    PubMed

    Jokipii-Lukkari, Soile; Kastaniotis, Alexander J; Parkash, Vimal; Sundström, Robin; Leiva-Eriksson, Nélida; Nymalm, Yvonne; Blokhina, Olga; Kukkola, Eija; Fagerstedt, Kurt V; Salminen, Tiina A; Läärä, Esa; Bülow, Leif; Ohlmeier, Steffen; Hiltunen, J Kalervo; Kallio, Pauli T; Häggman, Hely

    2016-06-01

    Previous reports have connected non-symbiotic and truncated hemoglobins (Hbs) to metabolism of nitric oxide (NO), an important signalling molecule involved in wood formation. We have studied the capability of poplar (Populus tremula × tremuloides) Hbs PttHb1 and PttTrHb proteins alone or with a flavin-protein reductase to relieve NO cytotoxicity in living cells. Complementation tests in a Hb-deficient, NO-sensitive yeast (Saccharomyces cerevisiae) Δyhb1 mutant showed that neither PttHb1 nor PttTrHb alone protected cells against NO. To study the ability of Hbs to interact with a reductase, ferredoxin NADP(+) oxidoreductase PtthFNR was characterized by sequencing and proteomics. To date, by far the greatest number of the known dual-targeted plant proteins are directed to chloroplasts and mitochondria. We discovered a novel variant of hFNR that lacks the plastid presequence and resides in cytosol. The coexpression of PttHb1 and PtthFNR partially restored NO resistance of the yeast Δyhb1 mutant, whereas PttTrHb coexpressed with PtthFNR failed to rescue growth. YFP fusion proteins confirmed the interaction between PttHb1 and PtthFNR in plant cells. The structural modelling results indicate that PttHb1 and PtthFNR are able to interact as NO dioxygenase. This is the first report on dual targeting of central plant enzyme FNR to plastids and cytosol. PMID:27095407

  12. Genomics Mechanisms of Carbon Allocation and Partitioning in Poplar

    SciTech Connect

    Kirst, Matias; Peter, Gary; Martin, Timothy

    2009-07-30

    The genetic control of carbon allocation and partitioning in woody perennial plants is poorly understood despite its importance for carbon sequestration. It is also unclear how environmental cues such as nitrogen availability impact the genes that regulate growth, and biomass allocation and wood composition in trees. To address these questions we phenotyped 396 clonally replicated genotypes of an interspecific pseudo-backcross pedigree of Populus for wood composition and biomass traits in above and below ground organs. The loci that regulate growth, carbon allocation and partitioning under two nitrogen conditions were identified, defining the contribution of environmental cues to their genetic control. Fifty-seven quantitative trait loci (QTL) were identified for twenty traits analyzed. The majority of QTL are specific to one of the two nitrogen treatments, demonstrating significant nitrogen-dependent genetic control. A highly significant genetic correlation was observed between plant growth and lignin/cellulose composition, and QTL co-localization identified the genomic position of potential pleiotropic regulators. Gene expression analysis of all poplar genes was also characterized in differentiating xylem, whole-roots and developing leaves of 192 of the segregating population. By integrating the QTL and gene expression information we identified genes that regulate carbon partitioning and several biomass growth related properties. The work developed in this project resulted in the publication of three book chapters, four scientific articles (three others currently in preparation), 17 presentations in international conferences and two provisional patent applications.

  13. Biological monitoring program for East Fork Poplar Creek

    SciTech Connect

    Adams, S.M.; Ashwood, T.L.; Beaty, T.W.; Brandt, C.C.; Christensen, S.W.; Cicerone, D.S.; Greeley, M.S. Jr.; Hill, W.R.; Kszos, L.S.

    1997-04-18

    In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the complex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity of EFPC. These tasks are (1) toxicity monitoring, (2) biological indicator studies, (3) bioaccumulation studies, and (4) ecological surveys of the periphyton, benthic macroinvertebrate, and fish communities.

  14. Polyphenol Oxidase from Hybrid Poplar. Cloning and Expression in Response to Wounding and Herbivory1

    PubMed Central

    Constabel, C. Peter; Yip, Lynn; Patton, Joseph J.; Christopher, Mary E.

    2000-01-01

    The inducible expression of polyphenol oxidase (PPO), a presumed antiherbivore enzyme, was examined in hybrid poplar (Populus trichocarpa × Populus deltoides). Following mechanical wounding simulating insect damage, PPO activity increased dramatically in wounded and unwounded leaves on wounded plants beginning at 24 and 48 h, respectively. A hybrid poplar PPO cDNA was isolated and its nucleotide sequence determined. On northern blots, PPO transcripts were detected within 8 h of wounding, and reached peak levels at 16 and 24 h in wounded and unwounded leaves, respectively. Methyl jasmonate spray and feeding by forest tent caterpillar also induced PPO expression. The induction of PPO was strongest in the youngest four leaves, which were generally avoided by caterpillars in free feeding experiments. This wound- and herbivore-induced expression of PPO in hybrid poplar supports the defensive role of this protein against insect pests. PMID:10982443

  15. Effect of autohydrolysis on the wettability, absorbility and further alkali impregnation of poplar wood chips.

    PubMed

    Xu, Ningpan; Liu, Wei; Hou, Qingxi; Wang, Peiyun; Yao, Zhirong

    2016-09-01

    Autohydrolysis with different severity factors was performed on poplar wood chips prior to pulping, and the wettability, absorbility and the following impregnation of NaOH solution for the poplar wood chips were then investigated. The results showed that after autohydrolysis pretreatment the porosity, shrinkage and fiber saturation point (FSP) of the poplar wood chips were increased, while the surface contact angle decreased as the severity factor was increased. The autohydrolyzed chips absorbed more NaOH in impregnation that resulted in a low NaOH concentration in the bulk impregnation liquor (i.e., the impregnation liquor outside wood chips), while the concentration in the entrapped liquor (i.e., the impregnation liquor inside wood chips) was increased. Autohydrolysis substantially improved the effectiveness of alkali impregnation. PMID:27259186

  16. Polyphenol oxidase from hybrid poplar. Cloning and expression in response to wounding and herbivory.

    PubMed

    Constabel, C P; Yip, L; Patton, J J; Christopher, M E

    2000-09-01

    The inducible expression of polyphenol oxidase (PPO), a presumed antiherbivore enzyme, was examined in hybrid poplar (Populus trichocarpa x Populus deltoides). Following mechanical wounding simulating insect damage, PPO activity increased dramatically in wounded and unwounded leaves on wounded plants beginning at 24 and 48 h, respectively. A hybrid poplar PPO cDNA was isolated and its nucleotide sequence determined. On northern blots, PPO transcripts were detected within 8 h of wounding, and reached peak levels at 16 and 24 h in wounded and unwounded leaves, respectively. Methyl jasmonate spray and feeding by forest tent caterpillar also induced PPO expression. The induction of PPO was strongest in the youngest four leaves, which were generally avoided by caterpillars in free feeding experiments. This wound- and herbivore-induced expression of PPO in hybrid poplar supports the defensive role of this protein against insect pests.

  17. Daytime and nighttime wind differentially affects hydraulic properties and thigmomorphogenic response of poplar saplings.

    PubMed

    Huang, Ping; Wan, Xianchong; Lieffers, Victor J

    2016-05-01

    This study tested how wind in daytime and nighttime affects hydraulic properties and thigmomorphogenic response of poplar saplings. It shows that wind in daytime interrupted water balance of poplar plants by aggravating cavitation in the stem xylem under high xylem tension in the daytime, reducing water potential in midday and hence reducing gas exchange, including stomatal conductance and CO2 assimilation. The wind blowing in daytime significantly reduced plant growth, including height, diameter, leaf size, leaf area, root and whole biomass, whereas wind blowing in nighttime only caused a reduction in radial and height growth at the early stage compared with the control but decreased height:diameter ratios. In summary, the interaction between wind loading and xylem tension exerted a negative impact on water balance, gas exchanges and growth of poplar plants, and wind in nighttime caused only a small thigmomorphogenic response. PMID:26541407

  18. Can transgenic mosquitoes afford the fitness cost?

    PubMed

    Lambrechts, Louis; Koella, Jacob C; Boëte, Christophe

    2008-01-01

    In a recent study, SM1-transgenic Anopheles stephensi, which are resistant partially to Plasmodium berghei, had higher fitness than non-transgenic mosquitoes when they were maintained on Plasmodium-infected blood. This result should be interpreted cautiously with respect to malaria control using transgenic mosquitoes because, despite the evolutionary advantage conferred by the transgene, a concomitant cost prevents it from invading the entire population. Indeed, for the spread of a resistance transgene in a natural situation, the transgene's fitness cost and the efficacy of the gene drive will be more crucial than any evolutionary advantage.

  19. Apoplast proteome reveals that extracellular matrix contributes to multistress response in poplar

    PubMed Central

    2010-01-01

    Background Riverine ecosystems, highly sensitive to climate change and human activities, are characterized by rapid environmental change to fluctuating water levels and siltation, causing stress on their biological components. We have little understanding of mechanisms by which riverine plant species have developed adaptive strategies to cope with stress in dynamic environments while maintaining growth and development. Results We report that poplar (Populus spp.) has evolved a systems level "stress proteome" in the leaf-stem-root apoplast continuum to counter biotic and abiotic factors. To obtain apoplast proteins from P. deltoides, we developed pressure-chamber and water-displacement methods for leaves and stems, respectively. Analyses of 303 proteins and corresponding transcripts coupled with controlled experiments and bioinformatics demonstrate that poplar depends on constitutive and inducible factors to deal with water, pathogen, and oxidative stress. However, each apoplast possessed a unique set of proteins, indicating that response to stress is partly compartmentalized. Apoplast proteins that are involved in glycolysis, fermentation, and catabolism of sucrose and starch appear to enable poplar to grow normally under water stress. Pathogenesis-related proteins mediating water and pathogen stress in apoplast were particularly abundant and effective in suppressing growth of the most prevalent poplar pathogen Melampsora. Unexpectedly, we found diverse peroxidases that appear to be involved in stress-induced cell wall modification in apoplast, particularly during the growing season. Poplar developed a robust antioxidative system to buffer oxidation in stem apoplast. Conclusion These findings suggest that multistress response in the apoplast constitutes an important adaptive trait for poplar to inhabit dynamic environments and is also a potential mechanism in other riverine plant species. PMID:21114852

  20. Methylation of microRNA genes regulates gene expression in bisexual flower development in andromonoecious poplar.

    PubMed

    Song, Yuepeng; Tian, Min; Ci, Dong; Zhang, Deqiang

    2015-04-01

    Previous studies showed sex-specific DNA methylation and expression of candidate genes in bisexual flowers of andromonoecious poplar, but the regulatory relationship between methylation and microRNAs (miRNAs) remains unclear. To investigate whether the methylation of miRNA genes regulates gene expression in bisexual flower development, the methylome, microRNA, and transcriptome were examined in female and male flowers of andromonoecious poplar. 27 636 methylated coding genes and 113 methylated miRNA genes were identified. In the coding genes, 64.5% of the methylated reads mapped to the gene body region; by contrast, 60.7% of methylated reads in miRNA genes mainly mapped in the 5' and 3' flanking regions. CHH methylation showed the highest methylation levels and CHG showed the lowest methylation levels. Correlation analysis showed a significant, negative, strand-specific correlation of methylation and miRNA gene expression (r=0.79, P <0.05). The methylated miRNA genes included eight long miRNAs (lmiRNAs) of 24 nucleotides and 11 miRNAs related to flower development. miRNA172b might play an important role in the regulation of bisexual flower development-related gene expression in andromonoecious poplar, via modification of methylation. Gynomonoecious, female, and male poplars were used to validate the methylation patterns of the miRNA172b gene, implying that hyper-methylation in andromonoecious and gynomonoecious poplar might function as an important regulator in bisexual flower development. Our data provide a useful resource for the study of flower development in poplar and improve our understanding of the effect of epigenetic regulation on genes other than protein-coding genes.

  1. Methylation of microRNA genes regulates gene expression in bisexual flower development in andromonoecious poplar

    PubMed Central

    Song, Yuepeng; Tian, Min; Ci, Dong; Zhang, Deqiang

    2015-01-01

    Previous studies showed sex-specific DNA methylation and expression of candidate genes in bisexual flowers of andromonoecious poplar, but the regulatory relationship between methylation and microRNAs (miRNAs) remains unclear. To investigate whether the methylation of miRNA genes regulates gene expression in bisexual flower development, the methylome, microRNA, and transcriptome were examined in female and male flowers of andromonoecious poplar. 27 636 methylated coding genes and 113 methylated miRNA genes were identified. In the coding genes, 64.5% of the methylated reads mapped to the gene body region; by contrast, 60.7% of methylated reads in miRNA genes mainly mapped in the 5′ and 3′ flanking regions. CHH methylation showed the highest methylation levels and CHG showed the lowest methylation levels. Correlation analysis showed a significant, negative, strand-specific correlation of methylation and miRNA gene expression (r=0.79, P <0.05). The methylated miRNA genes included eight long miRNAs (lmiRNAs) of 24 nucleotides and 11 miRNAs related to flower development. miRNA172b might play an important role in the regulation of bisexual flower development-related gene expression in andromonoecious poplar, via modification of methylation. Gynomonoecious, female, and male poplars were used to validate the methylation patterns of the miRNA172b gene, implying that hyper-methylation in andromonoecious and gynomonoecious poplar might function as an important regulator in bisexual flower development. Our data provide a useful resource for the study of flower development in poplar and improve our understanding of the effect of epigenetic regulation on genes other than protein-coding genes. PMID:25617468

  2. Physical and chemical characterizations of corn stover and poplar solids resulting from leading pretreatment technologies.

    PubMed

    Kumar, Rajeev; Mago, Gaurav; Balan, Venkatesh; Wyman, Charles E

    2009-09-01

    In order to investigate changes in substrate chemical and physical features after pretreatment, several characterizations were performed on untreated (UT) corn stover and poplar and their solids resulting pretreatments by ammonia fiber expansion (AFEX), ammonia recycled percolation (ARP), controlled pH, dilute acid, flowthrough, lime, and SO(2) technologies. In addition to measuring the chemical compositions including acetyl content, physical attributes determined were biomass crystallinity, cellulose degree of polymerization, cellulase adsorption capacity of pretreated solids and enzymatically extracted lignin, copper number, FT-IR responses, scanning electron microscopy (SEM) visualizations, and surface atomic composition by electron spectroscopy of chemical analysis (ESCA). Lime pretreatment removed the most acetyl groups from both corn stover and poplar, while AFEX removed the least. Low pH pretreatments depolymerized cellulose and enhanced biomass crystallinity much more than higher pH approaches. Lime pretreated corn stover solids and flowthrough pretreated poplar solids had the highest cellulase adsorption capacity, while dilute acid pretreated corn stover solids and controlled pH pretreated poplar solids had the least. Furthermore, enzymatically extracted AFEX lignin preparations for both corn stover and poplar had the lowest cellulase adsorption capacity. ESCA results showed that SO(2) pretreated solids had the highest surface O/C ratio for poplar, but for corn stover, the highest value was observed for dilute acid pretreatment with a Parr reactor. Although dependent on pretreatment and substrate, FT-IR data showed that along with changes in cross linking and chemical changes, pretreatments may also decrystallize cellulose and change the ratio of crystalline cellulose polymorphs (Ialpha/Ibeta).

  3. Energy partitioning and surface resistance of a poplar plantation in northern China

    NASA Astrophysics Data System (ADS)

    Kang, M.; Zhang, Z.; Noormets, A.; Fang, X.; Zha, T.; Zhou, J.; Sun, G.; McNulty, S. G.; Chen, J.

    2015-07-01

    Poplar (Populus sp.) plantations have been, on the one hand, broadly used in northern China for urban greening, combating desertification, as well as for paper and wood production. On the other hand, such plantations have been questioned occasionally for their possible negative impacts on water availability due to the higher water-use nature of poplar trees compared with other tree species in water-limited dryland regions. To further understand the acclimation of poplar species to semiarid environments and to evaluate the potential impacts of these plantations on the broader context of the region's water supply, we examine the variability of bulk resistance parameters and energy partitioning in a poplar (Populus euramericana cv. "74/76") plantation located in northern China over a 4-year period, encompassing both dry and wet conditions. The partitioning of available energy to latent heat flux (LE) decreased from 0.62 to 0.53 under mediated meteorological drought by irrigation applications. A concomitant increase in sensible heat flux (H) resulted in the increase of a Bowen ratio from 0.83 to 1.57. Partial correlation analysis indicated that surface resistance (Rs) normalized by leaf area index (LAI; Rs:LAI) increased by 50 % under drought conditions and was the dominant factor controlling the Bowen ratio. Furthermore, Rs was the main factor controlling LE during the growing season, even in wet years, as indicated by the decoupling coefficient (Ω = 0.45 and 0.39 in wet and dry years, respectively). Rs was also a major regulator of the LE / LEeq ratio, which decreased from 0.81 in wet years to 0.68 in dry years. All physiological and bioclimatological metrics indicated that the water demands of the poplar plantation were greater than the amount available through precipitation, highlighting the poor match of a water-intensive species like poplar for this water-limited region.

  4. Poplar Carbohydrate-Active Enzymes. Gene Identification and Expression Analyses1[W

    PubMed Central

    Geisler-Lee, Jane; Geisler, Matt; Coutinho, Pedro M.; Segerman, Bo; Nishikubo, Nobuyuki; Takahashi, Junko; Aspeborg, Henrik; Djerbi, Soraya; Master, Emma; Andersson-Gunnerås, Sara; Sundberg, Björn; Karpinski, Stanislaw; Teeri, Tuula T.; Kleczkowski, Leszek A.; Henrissat, Bernard; Mellerowicz, Ewa J.

    2006-01-01

    Over 1,600 genes encoding carbohydrate-active enzymes (CAZymes) in the Populus trichocarpa (Torr. & Gray) genome were identified based on sequence homology, annotated, and grouped into families of glycosyltransferases, glycoside hydrolases, carbohydrate esterases, polysaccharide lyases, and expansins. Poplar (Populus spp.) had approximately 1.6 times more CAZyme genes than Arabidopsis (Arabidopsis thaliana). Whereas most families were proportionally increased, xylan and pectin-related families were underrepresented and the GT1 family of secondary metabolite-glycosylating enzymes was overrepresented in poplar. CAZyme gene expression in poplar was analyzed using a collection of 100,000 expressed sequence tags from 17 different tissues and compared to microarray data for poplar and Arabidopsis. Expression of genes involved in pectin and hemicellulose metabolism was detected in all tissues, indicating a constant maintenance of transcripts encoding enzymes remodeling the cell wall matrix. The most abundant transcripts encoded sucrose synthases that were specifically expressed in wood-forming tissues along with cellulose synthase and homologs of KORRIGAN and ELP1. Woody tissues were the richest source of various other CAZyme transcripts, demonstrating the importance of this group of enzymes for xylogenesis. In contrast, there was little expression of genes related to starch metabolism during wood formation, consistent with the preferential flux of carbon to cell wall biosynthesis. Seasonally dormant meristems of poplar showed a high prevalence of transcripts related to starch metabolism and surprisingly retained transcripts of some cell wall synthesis enzymes. The data showed profound changes in CAZyme transcriptomes in different poplar tissues and pointed to some key differences in CAZyme genes and their regulation between herbaceous and woody plants. PMID:16415215

  5. Uptake of ferrocyanide in willow and poplar trees in a long term greenhouse experiment.

    PubMed

    Dimitrova, Tsvetelina; Repmann, Frank; Raab, Thomas; Freese, Dirk

    2015-04-01

    Phytoremediation of sites contaminated with iron cyanides can be performed using poplar and willow trees. Poplar and willow trees were grown in potting substrate spiked with ferrocyanide concentrations of up to 2,000 mg kg(-1) for 4 and 8 weeks respectively. Soil solution and leaf tissue of different age were sampled for total cyanide analysis every week. Chlorophyll content in the leaves was determined to quantify cyanide toxicity. Results showed that cyanide in the soil solution of spiked soils differed between treatments and on weekly basis and ranged from 0.5 to 1,200 mg l(-1). The maximum cyanide content in willow and poplar leaves was 518 mg kg(-1) fresh weight (FW) and 148 mg kg(-1) FW respectively. Cyanide accumulated in the leaves increased linearly with increasing cyanide concentration in the soil solution. On the long term, significantly more cyanide was accumulated in old leaf tissue than in young tissue. Chlorophyll content in poplar decreased linearly with increasing cyanide in the soil solution and in leaf tissue, and over time. The inhibitory concentration (IC50) value for poplars after 4 weeks of exposure was 173 mg l(-1) and for willow after 8 weeks of exposure-768 mg l(-1). Results show that willows tolerate much more cyanide and over a longer period than poplars, making them very appropriate for remediating sites highly contaminated with iron cyanides.

  6. Apoplast proteome reveals that extracellular matrix contributes to multi-stress response in poplar

    SciTech Connect

    Pechanova, Olga; Hsu, Chuan-Yu; Adams, Joshua P.; Pechan, Tibor; Vandervelde, Lindsay; Drnevich, Jenny; Jawdy, Sara; Adeli, Ardeshir; Suttle, Jeffrey; Lawrence, Amanda; Tschaplinski, Timothy J; Seguin, Armand; Yuceer, Cetin

    2010-01-01

    Riverine ecosystems, highly sensitive to climate change and human activities, are characterized by rapid environmental change to fluctuating water levels and siltation, causing stress on their biological components. We have little understanding of mechanisms by which riverine plant species have developed adaptive strategies to cope with stress in dynamic environments while maintaining growth and development. We report that poplar (Populus spp.) has evolved a systems level 'stress proteome' in the leaf-stem-root apoplast continuum to counter biotic and abiotic factors. To obtain apoplast proteins from P. deltoides, we developed pressure-chamber and water-displacement methods for leaves and stems, respectively. Analyses of 303 proteins and corresponding transcripts coupled with controlled experiments and bioinformatics demonstrate that poplar depends on constitutive and inducible factors to deal with water, pathogen, and oxidative stress. However, each apoplast possessed a unique set of proteins, indicating that response to stress is partly compartmentalized. Apoplast proteins that are involved in glycolysis, fermentation, and catabolism of sucrose and starch appear to enable poplar to grow normally under water stress. Pathogenesis-related proteins mediating water and pathogen stress in apoplast were particularly abundant and effective in suppressing growth of the most prevalent poplar pathogen Melampsora. Unexpectedly, we found diverse peroxidases that appear to be involved in stress-induced cell wall modification in apoplast, particularly during the growing season. Poplar developed a robust antioxidative system to buffer oxidation in stem apoplast. These findings suggest that multistress response in the apoplast constitutes an important adaptive trait for poplar to inhabit dynamic environments and is also a potential mechanism in other riverine plant species.

  7. Some important physical properties of laminated veneer lumber (Lvl) made from oriental beech and Lombardy poplar

    NASA Astrophysics Data System (ADS)

    Kılıç, Murat

    2012-09-01

    This study examined some physical characteristics of laminated veneer lumber (LVL) obtained in different compositions from cut veneers of Oriental beech (Fagus Orientalis Lipsky) and Lombardy poplar (Populus nigra) with thicknesses of 4 mm and 5 mm. Five each beech and poplar trees were felled with this objective. The PVAc (Kleiberit 303) and PU (Bizon Timber PU-Max Express) types of adhesive were used in lamination. The air-dry and oven dry densities, cell wall density and porosity, the value of volume density, shrinkage in a tangential and radial direction and volume swelling amounts were determined by preparing the specimens in accordance with the standards.

  8. Poplar-type Propolis: Chemical Composition, Botanical Origin and Biological Activity.

    PubMed

    Ristivojević, Petar; Trifković, Jelena; Andrić, Filip; Milojković-Opsenica, Dusanka

    2015-11-01

    Propolis is one of the most used natural products known for centuries for its beneficial effects. Due to significant differences in chemical composition of samples originating from different geographic and climatic zones it is crucial to characterize reliably each type of propolis. This article comprises the latest findings concerning the poplar type propolis, i.e. it gives a cross section of chemical composition, botanical origin and biological activity of poplar type propolis in order to encourage further investigations that would indicate its beneficial effects.

  9. Effect of hybrid poplar trees on microbial populations important to hazardous waste bioremediation

    SciTech Connect

    Jordahl, J.L.; Foster, L.; Schnoor, J.L.; Alvarez, P.J.J.

    1997-06-01

    Microbial concentrations of denitrifiers, pseudomonads, and monoaromatic petroleum hydrocarbon (BTX) degraders were significantly higher (p < 0.1) in soil samples from the rhizosphere of poplar trees than in adjacent agricultural soils, and atrazine degraders were found only in one rhizosphere sample. The relative abundance of these phenotypes (as a fraction of total heterotrophs) was not significantly different between rhizosphere and surrounding soils. Therefore, the poplar rhizosphere enhanced the growth of microbial populations that participate in natural bioremediation without exerting selective pressure for them.

  10. Cryopreservation of transgenic mouse lines.

    PubMed

    Pomeroy, K O

    1993-01-01

    A transgenic animal represents an enormous investment in time and money. Animals can be destroyed through disease, fire, malfuncnons in the control of the environment, negligence, sabotage, or accidental disposal. Researchers can protect valuable transgenic lines from accrdental destruction by "banking" them in liquid nitrogen. Cryopreservation can also reduce animal costs by decreasing the number of live animals investigators must maintain. Often, when one is trying to produce a transgenic animal, some lines will be derived that may not initially appear interesting. These animals can be stored in liquid nitrogen for future recovery and study. The maintenance of just one line of mice, say 25 mice at 15 cents/d, can cost over $1000 (US) in a single year. PMID:21390665

  11. Transpirational demand affects aquaporin expression in poplar roots.

    PubMed

    Laur, Joan; Hacke, Uwe G

    2013-05-01

    Isohydric plants tend to maintain a water potential homeostasis primarily by controlling water loss via stomatal conductance. However, there is accumulating evidence that plants can also modulate water uptake in a dynamic manner. The dynamics of water uptake are influenced by aquaporin-mediated changes in root hydraulics. Most studies in this area have been conducted on herbaceous plants, and less is known about responses of woody plants. Here a study was conducted to determine how roots of hybrid poplar plants (Populus trichocarpa×deltoides) respond to a step change in transpirational demand. The main objective was to measure the expression of selected aquaporin genes and to assess how transcriptional responses correspond to changes in root water flow (Q R) and other parameters of water relations. A subset of plants was grown in shade and was subsequently exposed to a 5-fold increase in light level. Another group of plants was grown at ~95% relative humidity (RH) and was then subjected to lower RH while the light level remained unchanged. Both plant groups experienced a transient drop in stem water potentials. At 28h after the increase in transpirational demand, water potentials recovered. This recovery was associated with changes in the expression of PIP1 and PIP2 subfamily genes and an increase in Q R. Stomata of plants growing at high RH were larger and showed incomplete closure after application of abscisic acid. Since stomatal conductance remained high and unchanged in these plants, it is suggested that the recovery in water potential in these plants was largely driven by the increase in Q R. PMID:23599275

  12. Post-establishment fertilization of Minnesota hybrid poplar plantations.

    SciTech Connect

    Coleman, M., D.; Tolsted, D.; Nichols, T.; Johnson, W., D.; Ween, E.G.; Houghtaling, T.

    2006-01-01

    Experimental plantings were installed at five sites in three locations in western Minnesota. Aboveground biomass production increased 43-82% as a result of three annual applications of urea or balanced nutrient blend fertilizer beginning near canopy closure. There were no production differences between the type of fertilizer used, indicating that N was the major limiting nutrient. Responses were consistent from site to site, indicating that hybrid poplar stands in this region at this stage of development would be very responsive to fertilization. Leaf tissue N, P, and K concentrations increased in response to both fertilizer treatments; P and K increased more frequently in response to the blend treatment compared to the N-only urea treatment. The diagnosis and recommendation integrated system (DRIS) indices indicated that the stands were near optimal nutritional balance prior to fertilization. Treatments increased individual leaf area and leaf litter production up to 33% and 37%, respectively. Canopy leaf area, leaf N concentration and the sum of DRIS indices were correlated with aboveground production. Growth efficiency, the ratio of production to canopy leaf area, increased with both fertilizer treatment and successive years of treatment, indicating improved stand vigor due to nutrient amendments. Stand production increased more in response to changes in leaf N concentration as stands aged. Plantation production continued to increase with increased internal N concentration even when deficiency levels or levels defined as sufficient for fast growth were exceeded. The correlation between aboveground production and the sum of DRIS indices shows that optimal nutrition at canopy closure may result in current aboveground dry matter production exceeding 13Mgha-1 yr-1. Multiple small-dose amendments appear to be effective in increasing production by maintaining high internal N concentrations.

  13. How To Produce and Characterize Transgenic Plants.

    ERIC Educational Resources Information Center

    Savka, Michael A.; Wang, Shu-Yi; Wilson, Mark

    2002-01-01

    Explains the process of establishing transgenic plants which is a very important tool in plant biology and modern agriculture. Produces transgenic plants with the ability to synthesize opines. (Contains 17 references.) (YDS)

  14. [Current status and industrialization of transgenic tomatoes].

    PubMed

    Wang, Ao-Xue; Chen, Xiu-Ling

    2011-09-01

    In this review, the progress in transgenic tomato research, including disease and insect resistance, herbicide resistance, stress tolerance, long-term storage, quality improvement, and male sterility, were described. The recent researches on producing heterologous proteins using transgenic tomatoes were also reviewed. Furthermore, the industrialization status and problems of transgenic tomatoes were analyzed and the prospects of both research and industrialization in transgenic tomatoes were discussed.

  15. Human health and transgenic crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Under the joint auspices of the Agrochemical and the Agricultural and Food Chemistry Divisions of the American Chemical Society, we organized a short symposium on “Human Health and Transgenic Crops” at the 244th ACS national meeting, held August 19-23, 2012 in Philadelphia, PA, to examine an array o...

  16. Lignin engineering in field-grown poplar trees affects the endosphere bacterial microbiome

    PubMed Central

    Beckers, Bram; Op De Beeck, Michiel; Weyens, Nele; Van Acker, Rebecca; Van Montagu, Marc; Boerjan, Wout; Vangronsveld, Jaco

    2016-01-01

    Cinnamoyl-CoA reductase (CCR), an enzyme central to the lignin biosynthetic pathway, represents a promising biotechnological target to reduce lignin levels and to improve the commercial viability of lignocellulosic biomass. However, silencing of the CCR gene results in considerable flux changes of the general and monolignol-specific lignin pathways, ultimately leading to the accumulation of various extractable phenolic compounds in the xylem. Here, we evaluated host genotype-dependent effects of field-grown, CCR-down-regulated poplar trees (Populus tremula × Populus alba) on the bacterial rhizosphere microbiome and the endosphere microbiome, namely the microbiota present in roots, stems, and leaves. Plant-associated bacteria were isolated from all plant compartments by selective isolation and enrichment techniques with specific phenolic carbon sources (such as ferulic acid) that are up-regulated in CCR-deficient poplar trees. The bacterial microbiomes present in the endosphere were highly responsive to the CCR-deficient poplar genotype with remarkably different metabolic capacities and associated community structures compared with the WT trees. In contrast, the rhizosphere microbiome of CCR-deficient and WT poplar trees featured highly overlapping bacterial community structures and metabolic capacities. We demonstrate the host genotype modulation of the plant microbiome by minute genetic variations in the plant genome. Hence, these interactions need to be taken into consideration to understand the full consequences of plant metabolic pathway engineering and its relation with the environment and the intended genetic improvement. PMID:26755604

  17. Vulnerability to drought-induced cavitation in poplars: synthesis and future opportunities.

    PubMed

    Fichot, Régis; Brignolas, Franck; Cochard, Hervé; Ceulemans, Reinhart

    2015-07-01

    Vulnerability to drought-induced cavitation is a key trait of plant water relations. Here, we summarize the available literature on vulnerability to drought-induced cavitation in poplars (Populus spp.), a genus of agronomic, ecological and scientific importance. Vulnerability curves and vulnerability parameters (including the water potential inducing 50% loss in hydraulic conductivity, P50) were collected from 37 studies published between 1991 and 2014, covering a range of 10 species and 12 interspecific hybrid crosses. Results of our meta-analysis confirm that poplars are among the most vulnerable woody species to drought-induced cavitation (mean P50  = -1.44 and -1.55 MPa across pure species and hybrids, respectively). Yet, significant variation occurs among species (P50 range: 1.43 MPa) and among hybrid crosses (P50 range: 1.12 MPa), within species and hybrid crosses (max. P50 range reported: 0.8 MPa) as well as in response to environmental factors including nitrogen fertilization, irradiance, temperature and drought (max. P50 range reported: 0.75 MPa). Potential implications and gaps in knowledge are discussed in the context of poplar cultivation, species adaptation and climate modifications. We suggest that poplars represent a valuable model for studies on drought-induced cavitation, especially to elucidate the genetic and molecular basis of cavitation resistance in Angiosperms.

  18. Thaumatin-like proteins are differentially expressed and localized in phloem tissue of hybrid poplar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two thaumatin-like proteins (TLPs) were previously identified in phloem exudate of hybrid poplar (Populus trichocarpa x P. deltoides) using proteomics methods, and their sieve element localization confirmed by immunofluorescence. In the current study, we analyzed different tissues to further underst...

  19. Vulnerability to drought-induced cavitation in poplars: synthesis and future opportunities.

    PubMed

    Fichot, Régis; Brignolas, Franck; Cochard, Hervé; Ceulemans, Reinhart

    2015-07-01

    Vulnerability to drought-induced cavitation is a key trait of plant water relations. Here, we summarize the available literature on vulnerability to drought-induced cavitation in poplars (Populus spp.), a genus of agronomic, ecological and scientific importance. Vulnerability curves and vulnerability parameters (including the water potential inducing 50% loss in hydraulic conductivity, P50) were collected from 37 studies published between 1991 and 2014, covering a range of 10 species and 12 interspecific hybrid crosses. Results of our meta-analysis confirm that poplars are among the most vulnerable woody species to drought-induced cavitation (mean P50  = -1.44 and -1.55 MPa across pure species and hybrids, respectively). Yet, significant variation occurs among species (P50 range: 1.43 MPa) and among hybrid crosses (P50 range: 1.12 MPa), within species and hybrid crosses (max. P50 range reported: 0.8 MPa) as well as in response to environmental factors including nitrogen fertilization, irradiance, temperature and drought (max. P50 range reported: 0.75 MPa). Potential implications and gaps in knowledge are discussed in the context of poplar cultivation, species adaptation and climate modifications. We suggest that poplars represent a valuable model for studies on drought-induced cavitation, especially to elucidate the genetic and molecular basis of cavitation resistance in Angiosperms. PMID:25444560

  20. Large-scale hybrid poplar production economics: 1995 Alexandria, Minnesota establishment cost and management

    SciTech Connect

    Downing, M.; Langseth, D.; Stoffel, R.; Kroll, T.

    1996-12-31

    The purpose of this project was to track and monitor costs of planting, maintaining, and monitoring large scale commercial plantings of hybrid poplar in Minnesota. These costs assists potential growers and purchasers of this resource to determine the ways in which supply and demand may be secured through developing markets.

  1. Metabolic Responses of Poplar to Apripona germari (Hope) as Revealed by Metabolite Profiling

    PubMed Central

    Wang, Lijuan; Qu, Liangjian; Zhang, Liwei; Hu, Jianjun; Tang, Fang; Lu, Mengzhu

    2016-01-01

    Plants have developed biochemical responses to adapt to biotic stress. To characterize the resistance mechanisms in poplar tree against Apripona germari, comprehensive metabolomic changes of poplar bark and xylem in response to A. germari infection were examined by gas chromatography time-of-flight mass spectrometry (GC–TOF/MS). It was found that, four days after feeding (stage I), A. germari infection brought about changes in various metabolites, such as phenolics, amino acids and sugars in both bark and xylem. Quinic acid, epicatechin, epigallocatechin and salicin might play a role in resistance response in bark, while coniferyl alcohol, ferulic acid and salicin contribute resistance in xylem. At feeding stages II when the larvae fed for more than one month, fewer defensive metabolites were induced, but levels of many intermediates of glycolysis and the tricarboxylic acid (TCA) cycle were reduced, especially in xylem. These results suggested that the defense strategies against A. germari might depend mainly on the early defense responses in poplar. In addition, it was found that bark and xylem in infected trees accumulated higher levels of salicylic acid and 4-aminobutyric acid, respectively, these tissues displaying a direct and systemic reaction against A. germari. However, the actual role of the two metabolites in A. germari-induced defense in poplar requires further investigation. PMID:27331808

  2. Metabolic Responses of Poplar to Apripona germari (Hope) as Revealed by Metabolite Profiling.

    PubMed

    Wang, Lijuan; Qu, Liangjian; Zhang, Liwei; Hu, Jianjun; Tang, Fang; Lu, Mengzhu

    2016-01-01

    Plants have developed biochemical responses to adapt to biotic stress. To characterize the resistance mechanisms in poplar tree against Apripona germari, comprehensive metabolomic changes of poplar bark and xylem in response to A. germari infection were examined by gas chromatography time-of-flight mass spectrometry (GC-TOF/MS). It was found that, four days after feeding (stage I), A. germari infection brought about changes in various metabolites, such as phenolics, amino acids and sugars in both bark and xylem. Quinic acid, epicatechin, epigallocatechin and salicin might play a role in resistance response in bark, while coniferyl alcohol, ferulic acid and salicin contribute resistance in xylem. At feeding stages II when the larvae fed for more than one month, fewer defensive metabolites were induced, but levels of many intermediates of glycolysis and the tricarboxylic acid (TCA) cycle were reduced, especially in xylem. These results suggested that the defense strategies against A. germari might depend mainly on the early defense responses in poplar. In addition, it was found that bark and xylem in infected trees accumulated higher levels of salicylic acid and 4-aminobutyric acid, respectively, these tissues displaying a direct and systemic reaction against A. germari. However, the actual role of the two metabolites in A. germari-induced defense in poplar requires further investigation. PMID:27331808

  3. Effector-Mining in the Poplar Rust Fungus Melampsora larici-populina Secretome.

    PubMed

    Lorrain, Cécile; Hecker, Arnaud; Duplessis, Sébastien

    2015-01-01

    The poplar leaf rust fungus, Melampsora larici-populina has been established as a tree-microbe interaction model. Understanding the molecular mechanisms controlling infection by pathogens appears essential for durable management of tree plantations. In biotrophic plant-parasites, effectors are known to condition host cell colonization. Thus, investigation of candidate secreted effector proteins (CSEPs) is a major goal in the poplar-poplar rust interaction. Unlike oomycetes, fungal effectors do not share conserved motifs and candidate prediction relies on a set of a priori criteria established from reported bona fide effectors. Secretome prediction, genome-wide analysis of gene families and transcriptomics of M. larici-populina have led to catalogs of more than a thousand secreted proteins. Automatized effector-mining pipelines hold great promise for rapid and systematic identification and prioritization of CSEPs for functional characterization. In this review, we report on and discuss the current status of the poplar rust fungus secretome and prediction of candidate effectors from this species. PMID:26697026

  4. Association analysis identifies Melampsora ×columbiana poplar leaf rust resistance SNPs.

    PubMed

    La Mantia, Jonathan; Klápště, Jaroslav; El-Kassaby, Yousry A; Azam, Shofiul; Guy, Robert D; Douglas, Carl J; Mansfield, Shawn D; Hamelin, Richard

    2013-01-01

    Populus species are currently being domesticated through intensive time- and resource-dependent programs for utilization in phytoremediation, wood and paper products, and conversion to biofuels. Poplar leaf rust disease can greatly reduce wood volume. Genetic resistance is effective in reducing economic losses but major resistance loci have been race-specific and can be readily defeated by the pathogen. Developing durable disease resistance requires the identification of non-race-specific loci. In the presented study, area under the disease progress curve was calculated from natural infection of Melampsora ×columbiana in three consecutive years. Association analysis was performed using 412 P. trichocarpa clones genotyped with 29,355 SNPs covering 3,543 genes. We found 40 SNPs within 26 unique genes significantly associated (permutated P<0.05) with poplar rust severity. Moreover, two SNPs were repeated in all three years suggesting non-race-specificity and three additional SNPs were differentially expressed in other poplar rust interactions. These five SNPs were found in genes that have orthologs in Arabidopsis with functionality in pathogen induced transcriptome reprogramming, Ca²⁺/calmodulin and salicylic acid signaling, and tolerance to reactive oxygen species. The additive effect of non-R gene functional variants may constitute high levels of durable poplar leaf rust resistance. Therefore, these findings are of significance for speeding the genetic improvement of this long-lived, economically important organism.

  5. Association Analysis Identifies Melampsora ×columbiana Poplar Leaf Rust Resistance SNPs

    PubMed Central

    La Mantia, Jonathan; Klápště, Jaroslav; El-Kassaby, Yousry A.; Azam, Shofiul; Guy, Robert D.; Douglas, Carl J.; Mansfield, Shawn D.; Hamelin, Richard

    2013-01-01

    Populus species are currently being domesticated through intensive time- and resource-dependent programs for utilization in phytoremediation, wood and paper products, and conversion to biofuels. Poplar leaf rust disease can greatly reduce wood volume. Genetic resistance is effective in reducing economic losses but major resistance loci have been race-specific and can be readily defeated by the pathogen. Developing durable disease resistance requires the identification of non-race-specific loci. In the presented study, area under the disease progress curve was calculated from natural infection of Melampsora ×columbiana in three consecutive years. Association analysis was performed using 412 P. trichocarpa clones genotyped with 29,355 SNPs covering 3,543 genes. We found 40 SNPs within 26 unique genes significantly associated (permutated P<0.05) with poplar rust severity. Moreover, two SNPs were repeated in all three years suggesting non-race-specificity and three additional SNPs were differentially expressed in other poplar rust interactions. These five SNPs were found in genes that have orthologs in Arabidopsis with functionality in pathogen induced transcriptome reprogramming, Ca2+/calmodulin and salicylic acid signaling, and tolerance to reactive oxygen species. The additive effect of non-R gene functional variants may constitute high levels of durable poplar leaf rust resistance. Therefore, these findings are of significance for speeding the genetic improvement of this long-lived, economically important organism. PMID:24236018

  6. Nucleotide diversity among natural populations of a North American poplar (Populus balsamifera, Salicaceae).

    PubMed

    Breen, Amy L; Glenn, Elise; Yeager, Adam; Olson, Matthew S

    2009-01-01

    Poplars (Populus spp.) comprise an important component of circumpolar boreal forest ecosystems and are the model species for tree genomics. In this study, we surveyed genetic variation and population differentiation in three nuclear genes among populations of balsam poplar (Populus balsamifera) in North America. We examined nucleotide sequence variation in alcohol dehydrogenase 1 (Adh1) and glyceraldehyde 3-phosphate dehydrogenase (G3pdh), two well-studied nuclear loci in plants, and abscisic acid insensitivity 1B (ABI1B), a locus coincident with timing of seasonal dormancy in quantitative trait locus (QTL) studies of hybrid poplars. We compared estimates of baseline population genetic parameters for these loci with those obtained in studies of other poplar species, particularly European aspen (Populus tremula). Average pairwise nucleotide diversity (pi(tot) = 0.00216-0.00353) was equivalent to that in Populus trichocarpa, but markedly less than that in P. tremula. Elevated levels of population structure were observed in ABI1B between the northern and southern regions (F(CT) = 0.184, P < 0.001) and among populations (F(ST) = 0.256, P < 0.001). These results suggest that geographic or taxonomic factors are important for understanding patterns of variation throughout the genus Populus. Our findings have the potential to aid in the design of sampling regimes for conservation and breeding stock and contribute to historical inferences regarding the factors that shaped the genetic diversity of boreal plant species.

  7. Environmental metabarcoding reveals contrasting microbial communities at two poplar phytomanagement sites.

    PubMed

    Foulon, Julie; Zappelini, Cyril; Durand, Alexis; Valot, Benoit; Girardclos, Olivier; Blaudez, Damien; Chalot, Michel

    2016-11-15

    The aim of the present study is to deepen the current understanding of the microbial communities at two poplar phytomanagement sites to reveal the environmental factors that drive the abundance, diversity and composition of microbial communities. A soil analysis revealed that the two soils displayed contrasting physico-chemical characteristics, with significant lower pH and higher Cd, Zn and Mn CaCl2-extractable fractions at Leforest site, compared with Pierrelaye site. The fungal and bacterial community profiles in the poplar roots and soils were assessed through Illumina MiSeq sequencing. Diversity indices and β-diversity measures illustrated that the root microbial communities were well separated from the soil microbial communities at both sites. A detailed study of the fungal composition showed that Ascomycota dominated the overall fungal communities on poplar soil, the root samples at Pierrelaye, and the unplanted soil at the experimental sites. Conversely, Basidiomycota accounted for a much higher percentage of the fungal community in poplar root samples from the Leforest site. The root bacterial communities were dominated by Alphaproteobacteria and Actinobacteria, and the soil samples were dominated by Alphaproteobacteria and Acidobacteria. The occurrence and dominance of the ectomycorrhizal community at Leforest but not at Pierrelaye is the major feature of our data set. Overall, ectomycorrhizal root symbionts appeared to be highly constrained by soil characteristics at the phytomanagement sites. Our data support the view that mycorrhizal inoculation is needed in highly stressed and nutrient-poor environments.

  8. Lignin engineering in field-grown poplar trees affects the endosphere bacterial microbiome.

    PubMed

    Beckers, Bram; Op De Beeck, Michiel; Weyens, Nele; Van Acker, Rebecca; Van Montagu, Marc; Boerjan, Wout; Vangronsveld, Jaco

    2016-02-23

    Cinnamoyl-CoA reductase (CCR), an enzyme central to the lignin biosynthetic pathway, represents a promising biotechnological target to reduce lignin levels and to improve the commercial viability of lignocellulosic biomass. However, silencing of the CCR gene results in considerable flux changes of the general and monolignol-specific lignin pathways, ultimately leading to the accumulation of various extractable phenolic compounds in the xylem. Here, we evaluated host genotype-dependent effects of field-grown, CCR-down-regulated poplar trees (Populus tremula × Populus alba) on the bacterial rhizosphere microbiome and the endosphere microbiome, namely the microbiota present in roots, stems, and leaves. Plant-associated bacteria were isolated from all plant compartments by selective isolation and enrichment techniques with specific phenolic carbon sources (such as ferulic acid) that are up-regulated in CCR-deficient poplar trees. The bacterial microbiomes present in the endosphere were highly responsive to the CCR-deficient poplar genotype with remarkably different metabolic capacities and associated community structures compared with the WT trees. In contrast, the rhizosphere microbiome of CCR-deficient and WT poplar trees featured highly overlapping bacterial community structures and metabolic capacities. We demonstrate the host genotype modulation of the plant microbiome by minute genetic variations in the plant genome. Hence, these interactions need to be taken into consideration to understand the full consequences of plant metabolic pathway engineering and its relation with the environment and the intended genetic improvement. PMID:26755604

  9. Lignin engineering in field-grown poplar trees affects the endosphere bacterial microbiome.

    PubMed

    Beckers, Bram; Op De Beeck, Michiel; Weyens, Nele; Van Acker, Rebecca; Van Montagu, Marc; Boerjan, Wout; Vangronsveld, Jaco

    2016-02-23

    Cinnamoyl-CoA reductase (CCR), an enzyme central to the lignin biosynthetic pathway, represents a promising biotechnological target to reduce lignin levels and to improve the commercial viability of lignocellulosic biomass. However, silencing of the CCR gene results in considerable flux changes of the general and monolignol-specific lignin pathways, ultimately leading to the accumulation of various extractable phenolic compounds in the xylem. Here, we evaluated host genotype-dependent effects of field-grown, CCR-down-regulated poplar trees (Populus tremula × Populus alba) on the bacterial rhizosphere microbiome and the endosphere microbiome, namely the microbiota present in roots, stems, and leaves. Plant-associated bacteria were isolated from all plant compartments by selective isolation and enrichment techniques with specific phenolic carbon sources (such as ferulic acid) that are up-regulated in CCR-deficient poplar trees. The bacterial microbiomes present in the endosphere were highly responsive to the CCR-deficient poplar genotype with remarkably different metabolic capacities and associated community structures compared with the WT trees. In contrast, the rhizosphere microbiome of CCR-deficient and WT poplar trees featured highly overlapping bacterial community structures and metabolic capacities. We demonstrate the host genotype modulation of the plant microbiome by minute genetic variations in the plant genome. Hence, these interactions need to be taken into consideration to understand the full consequences of plant metabolic pathway engineering and its relation with the environment and the intended genetic improvement.

  10. Exploring the role of asexual multiplication in poplar rust epidemics: impact on diversity and genetic structure.

    PubMed

    Barrès, Benoît; Dutech, Cyril; Andrieux, Axelle; Halkett, Fabien; Frey, Pascal

    2012-10-01

    Fungal plant pathogens, especially rust fungi (Pucciniales), are well known for their complex life cycles, which include phases of sexual and asexual reproduction. The effect of asexual multiplication on population genetic diversity has been investigated in the poplar rust fungus Melampsora larici-populina using a nested hierarchical sampling scheme. Four hierarchical levels were considered: leaf, twig, tree and site. Both cultivated and wild poplar stands were sampled at two time points at the start and end of rust epidemics. A total of 641 fungal isolates was analysed using nine microsatellite markers. This study revealed that the genetic signature of asexual multiplication in the wild poplar stand was seen only at lower hierarchical levels (leaf and twig). Moreover, we observed an erosion of clonal structure through time, with an increase in both gene and genotypic diversity. New genotypes contributed to host infection over time, which demonstrates the importance of allo-infection in the epidemic process in this host-pathogen system. Compared with the wild stands, the nearly lack of detection of clonal structure in the cultivated stands reflects the higher infection level on cultivated poplars. More generally, this genetic analysis illustrates the utility of population genetics approach for elucidating the proportion of asexual reproduction in the multiplication of isolates during an epidemic, and for proper quantification of asexual dispersal in plant pathogens.

  11. Gaseous NO2 effects on stomatal behavior, photosynthesis and respiration of hybrid poplar leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, we used poplar as a model plant and investigated the effects of gaseous nitrogen dioxide (NO2, 4 microliter per liter) on stomatal conductance, photosynthesis, dark- and photorespiration of Populus alba x Populus berolinensis hybrid leaves using the photosynthesis system and scanning...

  12. Storm water control plan for the Lower East Fork Poplar Creek Operable Unit, Oak Ridge, Tennessee

    SciTech Connect

    1996-04-01

    This document provides the Environmental Restoration Program with information about the erosion and sediment control, storm water management, maintenance, and reporting and record keeping practices to be employed during Phase II of the remediation project for the Lower East Fork Poplar Creek (LEFPC) Operable Unit.

  13. GENOME-ENABLED DISCOVERY OF CARBON SEQUESTRATION GENES IN POPLAR

    SciTech Connect

    DAVIS J M

    2007-10-11

    Plants utilize carbon by partitioning the reduced carbon obtained through photosynthesis into different compartments and into different chemistries within a cell and subsequently allocating such carbon to sink tissues throughout the plant. Since the phytohormones auxin and cytokinin are known to influence sink strength in tissues such as roots (Skoog & Miller 1957, Nordstrom et al. 2004), we hypothesized that altering the expression of genes that regulate auxin-mediated (e.g., AUX/IAA or ARF transcription factors) or cytokinin-mediated (e.g., RR transcription factors) control of root growth and development would impact carbon allocation and partitioning belowground (Fig. 1 - Renewal Proposal). Specifically, the ARF, AUX/IAA and RR transcription factor gene families mediate the effects of the growth regulators auxin and cytokinin on cell expansion, cell division and differentiation into root primordia. Invertases (IVR), whose transcript abundance is enhanced by both auxin and cytokinin, are critical components of carbon movement and therefore of carbon allocation. Thus, we initiated comparative genomic studies to identify the AUX/IAA, ARF, RR and IVR gene families in the Populus genome that could impact carbon allocation and partitioning. Bioinformatics searches using Arabidopsis gene sequences as queries identified regions with high degrees of sequence similarities in the Populus genome. These Populus sequences formed the basis of our transgenic experiments. Transgenic modification of gene expression involving members of these gene families was hypothesized to have profound effects on carbon allocation and partitioning.

  14. Stomatal characteristics of riparian poplar species in a semi-arid environment.

    PubMed

    Pearce, David W; Millard, Sandra; Bray, Douglas F; Rood, Stewart B

    2006-02-01

    Several native poplar species meet at the margins of their natural distributions in southern Alberta, Canada. In this semi-arid area, poplars are obligate riparian species but they occupy several intergrading ecoregions. Populus deltoides Bartr. ex Marsh predominates in the warmest and driest eastern prairie ecoregions; P. balsamifera L. occupies the cooler and wetter western parkland and montane ecoregions; and P. angustifolia James and hybrids between the species occur in the intermediate grassland ecoregions. We investigated stomatal characteristics of these poplars in 51 genotypes collected across the range of ecoregions and grown in a semi-arid common garden. Stomatal length differed among genotypes within species but did not differ among species, ranging from 19 to 22 microm. Total stomatal densities (adaxial plus abaxial) differed among genotypes within species but were similar among species (290-420 stomata mm(-2)). Single-surface stomatal densities differed among species and consequently, the ratio of adaxial:abaxial stomatal density also differed, ranging from 0.94 for P. deltoides to 0.27 for P. balsamifera, with intermediate stomatal density ratios in P. angustifolia and hybrids. In a subsequent study of a subset of the same genotypes, stomatal density was correlated with stomatal conductance (r2 = 0.75) and the conductance ratios differed among species in the same manner as the stomatal density ratios. We conclude that: (1) diverse poplar genotypes respond similarly to a semi-arid environment by producing comparatively small and dense stomata; (2) differences in stomatal density underlie differences in stomatal conductance and differences among species in stomatal density ratio or conductance ratio may reflect adaptation to climatic differences among ecoregions; and (3) there is substantial variation in stomatal characteristics within and among species and hybrids in this area that could be useful for the selection and breeding of poplars adapted to

  15. A NAC domain protein family contributing to the regulation of wood formation in poplar.

    PubMed

    Ohtani, Misato; Nishikubo, Nobuyuki; Xu, Bo; Yamaguchi, Masatoshi; Mitsuda, Nobutaka; Goué, Nadia; Shi, Fusun; Ohme-Takagi, Masaru; Demura, Taku

    2011-08-01

    Wood harvested from trees is one of the most widely utilized natural materials on our planet. Recent environmental issues have prompted an increase in the demand for wood, especially as a cost-effective and renewable resource for industry and energy, so it is important to understand the process of wood formation. In the present study, we focused on poplar (Populus trichocarpa) NAC domain protein genes which are homologous to well-known Arabidopsis transcription factors regulating the differentiation of xylem vessels and fiber cells. From phylogenetic analysis, we isolated 16 poplar NAC domain protein genes, and named them PtVNS (VND-, NST/SND- and SMB-related proteins) genes. Expression analysis revealed that 12 PtVNS (also called PtrWND) genes including both VND and NST groups were expressed in developing xylem tissue and phloem fiber, whereas in primary xylem vessels, only PtVNS/PtrWND genes of the VND group were expressed. By using the post-translational induction system of Arabidopsis VND7, a master regulator of xylem vessel element differentiation, many poplar genes functioning in xylem vessel differentiation downstream from NAC domain protein genes were identified. Transient expression assays showed the variation in PtVNS/PtrWND transactivation activity toward downstream genes, even between duplicate gene pairs. Furthermore, overexpression of PtVNS/PtrWND genes induced ectopic secondary wall thickening in poplar leaves as well as in Arabidopsis seedlings with different levels of induction efficiency according to the gene. These results suggest that wood formation in poplar is regulated by cooperative functions of the NAC domain proteins.

  16. Responses of energy partitioning and surface resistance to drought in a poplar plantation in northern China

    NASA Astrophysics Data System (ADS)

    Kang, M.; Zhang, Z.; Noormets, A.; Fang, X.; Zha, T.; Zhou, J.; Sun, G.; McNulty, S.; Chen, J.

    2015-01-01

    Poplar (Populus sp.) plantations have been used broadly for combating desertification, urban greening, and paper and wood production in northern China. However, given the high water use by the species and the regional dry environment, the long-term sustainability of these plantations needs to be evaluated. Currently, the understanding of energy partitioning and canopy resistance to water vapor and CO2 in poplar plantations is limited, impeding an accurate assessment of their true ecosystem functions. This study examined the variability of canopy bulk resistance parameters and energy partitioning over a four-year period encompassing both dry and wet conditions in a poplar (Populus euramericana CV. "74 / 76") plantation ecosystem located in northern China. Available energy (Net radiation Rn minus Soil Heat Flux, G) partitioning to latent (LE) and sensible (H) heat was responsive to climatological drought, with LE/(Rn-G) ranging from 62% in wet years (e.g. 2007 and 2008) to 53% in dry years (e.g. 2006 and 2009), and H/(Rn-G) from 25 to 33% between wet and dry years. Correspondingly, the Bowen ratio (β=H/LE) were 0.83 and 1.57. Surface resistance (Rs) had the greatest response to drought (+43%), but the aerodynamic and climatological resistances did not change significantly (p > 0.05). Partial correlation analysis indicated that Rs was the dominant factor in controlling the Bowen ratio. Furthermore, Rs was the major factor controlling LE during the growing season, even in wet years, as indicated by the decoupling coefficient (Ω = 0.45 and 0.39 in wet and dry years, respectively), and the LE / LEeq ratio ranged from 0.81 and 0.68 in wet and dry years, respectively. In general, the dry surface conditions dominated in this poplar plantation ecosystem regardless of soil water availability suggesting that fast-growing and water use-intensive species like poplar plantations are poorly adapted for the water limited region.

  17. Forest biorefinery: Potential of poplar phytochemicals as value-added co-products.

    PubMed

    Devappa, Rakshit K; Rakshit, Sudip K; Dekker, Robert F H

    2015-11-01

    The global forestry industry after experiencing a market downturn during the past decade has now aimed its vision towards the integrated biorefinery. New business models and strategies are constantly being explored to re-invent the global wood and pulp/paper industry through sustainable resource exploitation. The goal is to produce diversified, innovative and revenue generating product lines using on-site bioresources (wood and tree residues). The most popular product lines are generally produced from wood fibers (biofuels, pulp/paper, biomaterials, and bio/chemicals). However, the bark and other tree residues like foliage that constitute forest wastes, still remain largely an underexploited resource from which extractives and phytochemicals can be harnessed as by-products (biopharmaceuticals, food additives and nutraceuticals, biopesticides, cosmetics). Commercially, Populus (poplar) tree species including hybrid varieties are cultivated as a fast growing bioenergy crop, but can also be utilized to produce bio-based chemicals. This review identifies and underlines the potential of natural products (phytochemicals) from Populus species that could lead to new business ventures in biorefineries and contribute to the bioeconomy. In brief, this review highlights the importance of by-products/co-products in forest industries, methods that can be employed to extract and purify poplar phytochemicals, the potential pharmaceutical and other uses of >160 phytochemicals identified from poplar species - their chemical structures, properties and bioactivities, the challenges and limitations of utilizing poplar phytochemicals, and potential commercial opportunities. Finally, the overall discussion and conclusion are made considering the recent biotechnological advances in phytochemical research to indicate the areas for future commercial applications from poplar tree species.

  18. Photosynthesis and substrate supply for isoprene biosynthesis in poplar leaves

    NASA Astrophysics Data System (ADS)

    Magel, E.; Mayrhofer, S.; Müller, A.; Zimmer, I.; Hampp, R.; Schnitzler, J.-P.

    Gray poplar leaves emit high amounts of isoprene. In this context, we investigated the degree to which photosynthesis delivers necessary precursors for chloroplast isoprene biosynthesis, and whether this energy-consuming pathway could be involved in protecting the photosynthetic electron transport system. Such protection could result from consumption of a surplus in ATP and NADPH, generated under constricted net assimilation caused by high leaf temperatures and high light intensities. During the course of the day triose phosphate (TP) and dimethylallyl diphosphate (DMADP) concentrations showed pronounced diurnal variations closely related to net assimilation and isoprene emission rates, while other variables, e.g. energy (ATP/ADP) and redox (NADPH/NADP) ratio, as well as phosphoenolpyruvate (PEP) and pyruvate strongly scattered related to changing temperature and light intensities. Intra-day positive correlations were found mainly between leaf concentrations of TP and DMADP, and sucrose, ATP/ADP ratio and net assimilation rates. Under non-saturating light (200-400 μmol photons m -2 s -1), leaf DMADP pools were positively correlated mainly with PEP, starch, and fructose 2,6-bisphosphate (F26BP). Under saturating light, correlations improved and additionally involved sucrose, TP, and the ratio of NADPH/NADP. Study of temperature response curves showed that net assimilation and isoprene emission were negatively correlated to each other. This disconnection was mostly visible by the transient change of DMADP contents with maximum levels at 25 °C. At higher temperatures, declining pools of DMADP, TP and pyruvate indicated that DMADP consumption overcompensated DMADP production resulting in highest isoprene emission rates at declining pool sizes of precursors. In parallel to the reduction of net assimilation increases of NADPH/NADP and ATP/ADP ratios also portended that the MEP pathway dissipates a surplus of ATP and NADPH which cannot be used for carbon reduction under

  19. Poplar breeding and testing strategies in the NC US: Demonstration of potential yield and consideration of future research needs.

    SciTech Connect

    Riemenschneider, Don; Berguson, William E; Dickmann, Don; Hall, Richard

    2004-06-30

    The objective of this project was to extend previous poplar breeding and selection in the NC US by implementing a regional testing system with multiple test locations in Minnesota, Iowa, Wisconsin and Michigan.

  20. Predicting yields of short-rotation hybrid poplar (Populus spp.) for the United States through model-data synthesis.

    PubMed

    Wang, Dan; LeBauer, David; Dietze, Michael

    2013-06-01

    Hybrid poplar (Populus spp.) is an important biomass crop being evaluated for cellulosic ethanol production. Predictions of poplar growth, rotation period, and soil carbon sequestration under various growing conditions, soils, and climates are critical for farmers and managers planning to establish short-rotation forestry (SRF) plantations. In this study, we used an ecoinformatics workflow, the Predictive Ecosystem Analyzer (PEcAn), to integrate literature data and field measurements into the Ecosystem Demography 2 (ED2) model to estimate yield potential of poplar plantations. Within PEcAn 164 records of seven different traits from the literature were assimilated using a Bayesian meta-analysis. Next, variance decomposition identified seven variables for further constraint that contributed > 80% to the uncertainty in modeled yields: growth respiration, dark respiration, quantum efficiency, mortality coefficient, water conductance, fine-root allocation, and root turnover rate. Assimilation of observed yields further constrained uncertainty in model parameters (especially dark respiration and root turnover rate) and biomass estimates. Additional measurements of growth respiration, mortality, water conductance, and quantum efficiency would provide the most efficient path toward further constraint of modeled yields. Modeled validation demonstrated that ED2 successfully captured the interannual and spatial variability of poplar yield observed at nine independent sites. Site-level analyses were conducted to estimate the effect of land use change to SRF poplar on soil C sequestration compared to alternate land uses. These suggest that poplar plantations became a C sink within 18 years of conversion from corn production or existing forest. Finally, poplar yields were estimated for the contiguous United States at a half degree resolution in order to determine potential productivity, estimate the optimal rotation period, and compare poplar to perennial grass yields. This

  1. Predicting yields of short-rotation hybrid poplar (Populus spp.) for the United States through model-data synthesis.

    PubMed

    Wang, Dan; LeBauer, David; Dietze, Michael

    2013-06-01

    Hybrid poplar (Populus spp.) is an important biomass crop being evaluated for cellulosic ethanol production. Predictions of poplar growth, rotation period, and soil carbon sequestration under various growing conditions, soils, and climates are critical for farmers and managers planning to establish short-rotation forestry (SRF) plantations. In this study, we used an ecoinformatics workflow, the Predictive Ecosystem Analyzer (PEcAn), to integrate literature data and field measurements into the Ecosystem Demography 2 (ED2) model to estimate yield potential of poplar plantations. Within PEcAn 164 records of seven different traits from the literature were assimilated using a Bayesian meta-analysis. Next, variance decomposition identified seven variables for further constraint that contributed > 80% to the uncertainty in modeled yields: growth respiration, dark respiration, quantum efficiency, mortality coefficient, water conductance, fine-root allocation, and root turnover rate. Assimilation of observed yields further constrained uncertainty in model parameters (especially dark respiration and root turnover rate) and biomass estimates. Additional measurements of growth respiration, mortality, water conductance, and quantum efficiency would provide the most efficient path toward further constraint of modeled yields. Modeled validation demonstrated that ED2 successfully captured the interannual and spatial variability of poplar yield observed at nine independent sites. Site-level analyses were conducted to estimate the effect of land use change to SRF poplar on soil C sequestration compared to alternate land uses. These suggest that poplar plantations became a C sink within 18 years of conversion from corn production or existing forest. Finally, poplar yields were estimated for the contiguous United States at a half degree resolution in order to determine potential productivity, estimate the optimal rotation period, and compare poplar to perennial grass yields. This

  2. The Atlantic-Mediterranean watershed, river basins and glacial history shape the genetic structure of Iberian poplars.

    PubMed

    Macaya-Sanz, D; Heuertz, M; López-de-Heredia, U; De-Lucas, A I; Hidalgo, E; Maestro, C; Prada, A; Alía, R; González-Martínez, S C

    2012-07-01

    Recent phylogeographic studies have elucidated the effects of Pleistocene glaciations and of Pre-Pleistocene events on populations from glacial refuge areas. This study investigates those effects in riparian trees (Populus spp.), whose particular features may convey enhanced resistance to climate fluctuations. We analysed the phylogeographic structure of 44 white (Populus alba), 13 black (Populus nigra) and two grey (Populus x canescens) poplar populations in the Iberian Peninsula using plastid DNA microsatellites and sequences. We also assessed fine-scale spatial genetic structure and the extent of clonality in four white and one grey poplar populations using nuclear microsatellites and we determined quantitative genetic differentiation (Q(ST) ) for growth traits in white poplar. Black poplar displayed higher regional diversity and lower differentiation than white poplar, reflecting its higher cold-tolerance. The dependence of white poplar on phreatic water was evidenced by strong differentiation between the Atlantic and Mediterranean drainage basins and among river basins, and by weaker isolation by distance within than among river basins. Our results suggest confinement to the lower river courses during glacial periods and moderate interglacial gene exchange along coastlines. In northern Iberian river basins, white poplar had lower diversity, fewer private haplotypes and larger clonal assemblies than in southern basins, indicating a stronger effect of glaciations in the north. Despite strong genetic structure and frequent asexual propagation in white poplar, some growth traits displayed adaptive divergence between drainage and river basins (Q(ST) >F(ST)), highlighting the remarkable capacity of riparian tree populations to adapt to regional environmental conditions.

  3. Analyzing the impact of climate and management factors on the productivity and soil carbon sequestration of poplar plantations.

    PubMed

    Wang, Dan; Fan, Jiazhi; Jing, Panpan; Cheng, Yong; Ruan, Honghua

    2016-01-01

    It is crucial to investigate how climate and management factors impact poplar plantation production and soil carbon sequestration interactively. We extracted above-ground net primary production (ANPP), climate and management factors from peer-reviewed journal articles and analyzed impact of management factor and climate on the mean annual increment (MAI) of poplar ANPP statistically. Previously validated mechanistic model (ED) is used to perform case simulations for managed poplar plantations under different harvesting rotations. The meta-analysis indicate that the dry matter MAI was 6.3 Mg ha(-1) yr(-1) (n=641, sd=4.9) globally, and 5.1 (n=292, sd=4.0), 8.1 (n=224, sd=4.7) and 4.4 Mg ha(-1) yr(-1) (n=125, sd=3.2) in Europe, the US and China, respectively. Poplar MAI showed a significant response to GDD, precipitation and planting density and formed a quadratic relationship with stand age. The low annual production for poplar globally was probably caused by suboptimal water availability, rotation length and planting density. SEM attributes the variance of poplar growth rate more to climate than to management effects. Case simulations indicated that longer rotation cycle significantly increased soil carbon storage. Findings of this work suggests that management factor of rotation cycle alone could have dramatic impact on the above ground growth, as well as on the soil carbon sequestration of poplar plantations and will be helpful to quantify the long-term carbon sequestration through short rotation plantation. The findings of this study are useful in guiding further research, policy and management decisions towards sustainable poplar plantations.

  4. Identification of a novel hydroxylated metabolite of 2,2',3,5',6-pentachlorobiphenyl formed in whole poplar plants.

    PubMed

    Ma, Cunxian; Zhai, Guangshu; Wu, Huimin; Kania-Korwel, Izabela; Lehmler, Hans-Joachim; Schnoor, Jerald L

    2016-02-01

    Polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants consisting of 209 congeners. Oxidation of several PCB congeners to hydroxylated PCBs (OH-PCBs) in whole poplar plants has been reported before. Moreover, 2,2',3,5',6-pentachlorobiphenyl (PCB95), as a chiral congener, has been previously shown to be atropselectively taken up and transformed in whole poplar plants. The objective of this study was to determine if PCB95 is atropselectively metabolized to OH-PCBs in whole poplar plants. Two hydroxylated PCB95s were detected by high-performance liquid chromatography-mass spectrometry in the roots of whole poplar plants exposed to racemic PCB95 for 30 days. The major metabolite was confirmed to be 4'-hydroxy-2,2',3,5',6-pentachlorobiphenyl (4'-OH-PCB95) by gas chromatography-mass spectrometry (GC-MS) using an authentic reference standard. Enantioselective analysis showed that 4'-OH-PCB95 was formed atropselectively, with the atropisomer eluting second on the Nucleodex β-PM column (E2-4'-OH-PCB95) being slightly more abundant in the roots of whole poplar plants. Therefore, PCB95 can at least be metabolized into 4'-OH-PCB95 and another unknown hydroxylated PCB95 (as a minor metabolite) in whole poplar plants. Both atropisomers of 4'-OH-PCB95 are formed, but E2-4'-OH-PCB95 has greater atropisomeric enrichment in the roots of whole poplar plants. A comparison with mammalian biotransformation studies indicates a distinctively different metabolite profile of OH-PCB95 metabolites in whole poplar plants. Our observations suggest that biotransformation of chiral PCBs to OH-PCBs by plants may represent an important source of enantiomerically enriched OH-PCBs in the environment.

  5. Analyzing the impact of climate and management factors on the productivity and soil carbon sequestration of poplar plantations.

    PubMed

    Wang, Dan; Fan, Jiazhi; Jing, Panpan; Cheng, Yong; Ruan, Honghua

    2016-01-01

    It is crucial to investigate how climate and management factors impact poplar plantation production and soil carbon sequestration interactively. We extracted above-ground net primary production (ANPP), climate and management factors from peer-reviewed journal articles and analyzed impact of management factor and climate on the mean annual increment (MAI) of poplar ANPP statistically. Previously validated mechanistic model (ED) is used to perform case simulations for managed poplar plantations under different harvesting rotations. The meta-analysis indicate that the dry matter MAI was 6.3 Mg ha(-1) yr(-1) (n=641, sd=4.9) globally, and 5.1 (n=292, sd=4.0), 8.1 (n=224, sd=4.7) and 4.4 Mg ha(-1) yr(-1) (n=125, sd=3.2) in Europe, the US and China, respectively. Poplar MAI showed a significant response to GDD, precipitation and planting density and formed a quadratic relationship with stand age. The low annual production for poplar globally was probably caused by suboptimal water availability, rotation length and planting density. SEM attributes the variance of poplar growth rate more to climate than to management effects. Case simulations indicated that longer rotation cycle significantly increased soil carbon storage. Findings of this work suggests that management factor of rotation cycle alone could have dramatic impact on the above ground growth, as well as on the soil carbon sequestration of poplar plantations and will be helpful to quantify the long-term carbon sequestration through short rotation plantation. The findings of this study are useful in guiding further research, policy and management decisions towards sustainable poplar plantations. PMID:26531329

  6. Co-liquefaction of the Elbistan Lignite and Poplar Sawdust. Part I: The Effect of the Liquefaction Parameters

    SciTech Connect

    Karaca, H.; Acar, M.; Yilmaz, M.; Keklik, I.

    2009-07-01

    In this study, the liquefaction of Elbistan lignite and poplar sawdust, and the co-liquefaction of the Elbistan lignite and the poplar sawdust in an inert atmosphere and in non-catalytic conditions have been examined. Also, the effects of solvent/coal ratio and stirring speed on the total conversion derived as the result of the liquefaction process was attempted to be determined. Based on the results, although the effects of the solvent/coal ratio and the stirring speed on total conversion are similar for both the Elbistan lignite and the poplar sawdust, it was also noted that, under similar conditions, the conversion for the poplar sawdust was higher, as compared to the conversion of the Elbistan lignite. As the result of the liquefaction of Elbistan lignite and poplar sawdust under inert atmospheric conditions, the total conversion was increased partially, depending on both solvent/coal ratio and the speed of stirring. However, it was also noted that the total conversion did not change to a significant extent in high solvent/coal ratios and in stirring speed. As the result of the co-liquefaction of the Elbistan lignite and poplar sawdust under inert atmospheric conditions, total conversion was increased, based on the solvent/coal ratio. However, as in the case of the liquefaction of Elbistan lignite and poplar sawdust, it was noted that the high solvent/coal ratios (i.e., solvent/coal ratios of higher than 2/1) did not have a significant effect on the total conversion that was derived as the result of the co-liquefaction of the Elbistan lignite and poplar sawdust.

  7. Impact of 40 years poplar cultivation on soil carbon stocks and greenhouse gas fluxes

    NASA Astrophysics Data System (ADS)

    Ferré, C.; Leip, A.; Matteucci, G.; Previtali, F.; Seufert, G.

    2005-08-01

    Within the JRC Kyoto Experiment in the Regional Park and UN-Biosphere Reserve "Parco Ticino" (North-Italy, near Pavia), the soil carbon stocks and fluxes of CO2, N2O, and CH4 were measured in a poplar plantation in comparison with a natural mesohygrophilous deciduous forest nearby, which represents the pristine land cover of the area. Soil fluxes were measured using the static and dynamic closed chamber techniques for CH4 N2O, and CO2, respectively. We made further a pedological study to relate the spatial variability found with soil parameters.

    Annual emission fluxes of N2O and CO2 and deposition fluxes of CH4 were calculated for the year 2003 for the poplar plantation and compared to those measured at the natural forest site. N2O emissions at the poplar plantation were 0.15plusmn;0.1 g N2O m-2 y-1 and the difference to the emissions at the natural forest of 0.07±0.06 g N2O m-2 y-1 are partly due to a period of high emissions after the flooding of the site at the end of 2002. CH4 consumption at the natural forest was twice as large as at the poplar plantation. In comparison to the relict forest, carbon stocks in the soil under the poplar plantation were depleted by 61% of surface (10 cm) carbon and by 25% down the profile under tillage (45 cm). Soil respiration rates were not significant different at both sites with 1608±1053 and 2200±791 g CO2 m-2 y-1 at the poplar plantation and natural forest, respectively, indicating that soil organic carbon is much more stable in the natural forest. In terms of the greenhouse gas budget, the non-CO2 gases contributed minor to the overall soil balance with only 0.9% (N2O) and -0.3% (CH4 of CO2-eq emissions in the natural forest, and 2.7% (N2O) and -0.2% of CO2-eq. emissions in the poplar plantation.

    The very high spatial variability of soil fluxes within the two sites was related to the morphology of the floodplain area, which was formed by the historic course of

  8. Transgenic Arabidopsis Gene Expression System

    NASA Technical Reports Server (NTRS)

    Ferl, Robert; Paul, Anna-Lisa

    2009-01-01

    The Transgenic Arabidopsis Gene Expression System (TAGES) investigation is one in a pair of investigations that use the Advanced Biological Research System (ABRS) facility. TAGES uses Arabidopsis thaliana, thale cress, with sensor promoter-reporter gene constructs that render the plants as biomonitors (an organism used to determine the quality of the surrounding environment) of their environment using real-time nondestructive Green Fluorescent Protein (GFP) imagery and traditional postflight analyses.

  9. Stimulation of hybrid poplar growth in petroleum-contaminated soils through oxygen addition and soil nutrient amendments.

    PubMed

    Rentz, Jeremy A; Chapman, Brad; Alvarez, Pedro J J; Schnoor, Jerald L

    2003-01-01

    Hybrid poplar trees (Populus deltoides x nigra DN34) were grown in a green-house using hydrocarbon-contaminated soil from a phytoremediation demonstration site in Health, Ohio. Two independent experiments investigated the effect of nutrient addition on poplar growth and the importance of oxygen addition to root development and plant growth. Biomass measurements, poplar height, and leaf color were used as indicators of plant health in the selection of a 10/5/5 NPK fertilizer applied at 1121 kg/ha (112 kg-N, 24.4 kg-P, 46.5 kg-K per ha) to enhance hybrid poplar growth at the Health site. Five passive methods of oxygen delivery were examined, including aeration tubes, gravel addition, and an Oxygen Release Compound (ORC). When ORC was placed in coffee filters above hydrocarbon-contaminated soil, a statistically significant increase of 145% was observed in poplar biomass growth, relative to unamended controls. The ORC in filters also stimulated significant increases in root density. A 15.2-cm interval of soil directly below ORC addition exhibited an increase from 2.6 +/- 1.0 mg/cm3 to 4.8 +/- 1.0 mg/cm3, showing stimulation of root growth in hydrocarbon-stained soil. The positive response of hybrid poplars to oxygen amendments suggests that overcoming oxygen limitation to plants should be considered in phytoremediation projects when soil contamination exerts a high biochemical oxygen demand, such as in former refinery sites.

  10. Epigenetic Diversity of Clonal White Poplar (Populus alba L.) Populations: Could Methylation Support the Success of Vegetative Reproduction Strategy?

    PubMed Central

    Guarino, Francesco; Cicatelli, Angela; Brundu, Giuseppe; Heinze, Berthold; Castiglione, Stefano

    2015-01-01

    The widespread poplar populations of Sardinia are vegetatively propagated and live in different natural environments forming large monoclonal stands. The main goals of the present study were: i) to investigate/measure the epigenetic diversity of the poplar populations by determining their DNA methylation status; ii) to assess if and how methylation status influences population clustering; iii) to shed light on the changes that occur in the epigenome of ramets of the same poplar clone. To these purposes, 83 white poplar trees were sampled at different locations on the island of Sardinia. Methylation sensitive amplified polymorphism analysis was carried out on the genomic DNA extracted from leaves at the same juvenile stage. The study showed that the genetic biodiversity of poplars is quite limited but it is counterbalanced by epigenetic inter-population molecular variability. The comparison between MspI and HpaII DNA fragmentation profiles revealed that environmental conditions strongly influence hemi-methylation of the inner cytosine. The variable epigenetic status of Sardinian white poplars revealed a decreased number of population clusters. Landscape genetics analyses clearly demonstrated that ramets of the same clone were differentially methylated in relation to their geographic position. Therefore, our data support the notion that studies on plant biodiversity should no longer be restricted to genetic aspects, especially in the case of vegetatively propagated plant species. PMID:26147352

  11. Interaction between isoprene and ozone fluxes in a poplar plantation and its impact on air quality at the European level.

    PubMed

    Zenone, Terenzio; Hendriks, Carlijn; Brilli, Federico; Fransen, Erik; Gioli, Beniamio; Portillo-Estrada, Miguel; Schaap, Martijn; Ceulemans, Reinhart

    2016-09-12

    The emission of isoprene and other biogenic volatile organic compounds from vegetation plays an important role in tropospheric ozone (O3) formation. The potentially large expansion of isoprene emitting species (e.g., poplars) for bioenergy production might, therefore, impact tropospheric O3 formation. Using the eddy covariance technique we have simultaneously measured fluxes isoprene, O3 and of CO2 from a poplar (Populus) plantation grown for bioenergy production. We used the chemistry transport model LOTOS-EUROS to scale-up the isoprene emissions associated with the existing poplar plantations in Europe, and we assessed the impact of isoprene fluxes on ground level O3 concentrations. Our findings suggest that isoprene emissions from existing poplar-for-bioenergy plantations do not significantly affect the ground level of O3 concentration. Indeed the overall land in Europe covered with poplar plantations has not significantly changed over the last two decades despite policy incentives to produce bioenergy crops. The current surface area of isoprene emitting poplars-for-bioenergy remains too limited to significantly enhance O3 concentrations and thus to be considered a potential threat for air quality and human health.

  12. Stimulation of hybrid poplar growth in petroleum-contaminated soils through oxygen addition and soil nutrient amendments.

    PubMed

    Rentz, Jeremy A; Chapman, Brad; Alvarez, Pedro J J; Schnoor, Jerald L

    2003-01-01

    Hybrid poplar trees (Populus deltoides x nigra DN34) were grown in a green-house using hydrocarbon-contaminated soil from a phytoremediation demonstration site in Health, Ohio. Two independent experiments investigated the effect of nutrient addition on poplar growth and the importance of oxygen addition to root development and plant growth. Biomass measurements, poplar height, and leaf color were used as indicators of plant health in the selection of a 10/5/5 NPK fertilizer applied at 1121 kg/ha (112 kg-N, 24.4 kg-P, 46.5 kg-K per ha) to enhance hybrid poplar growth at the Health site. Five passive methods of oxygen delivery were examined, including aeration tubes, gravel addition, and an Oxygen Release Compound (ORC). When ORC was placed in coffee filters above hydrocarbon-contaminated soil, a statistically significant increase of 145% was observed in poplar biomass growth, relative to unamended controls. The ORC in filters also stimulated significant increases in root density. A 15.2-cm interval of soil directly below ORC addition exhibited an increase from 2.6 +/- 1.0 mg/cm3 to 4.8 +/- 1.0 mg/cm3, showing stimulation of root growth in hydrocarbon-stained soil. The positive response of hybrid poplars to oxygen amendments suggests that overcoming oxygen limitation to plants should be considered in phytoremediation projects when soil contamination exerts a high biochemical oxygen demand, such as in former refinery sites. PMID:12710235

  13. Interaction between isoprene and ozone fluxes in a poplar plantation and its impact on air quality at the European level.

    PubMed

    Zenone, Terenzio; Hendriks, Carlijn; Brilli, Federico; Fransen, Erik; Gioli, Beniamio; Portillo-Estrada, Miguel; Schaap, Martijn; Ceulemans, Reinhart

    2016-01-01

    The emission of isoprene and other biogenic volatile organic compounds from vegetation plays an important role in tropospheric ozone (O3) formation. The potentially large expansion of isoprene emitting species (e.g., poplars) for bioenergy production might, therefore, impact tropospheric O3 formation. Using the eddy covariance technique we have simultaneously measured fluxes isoprene, O3 and of CO2 from a poplar (Populus) plantation grown for bioenergy production. We used the chemistry transport model LOTOS-EUROS to scale-up the isoprene emissions associated with the existing poplar plantations in Europe, and we assessed the impact of isoprene fluxes on ground level O3 concentrations. Our findings suggest that isoprene emissions from existing poplar-for-bioenergy plantations do not significantly affect the ground level of O3 concentration. Indeed the overall land in Europe covered with poplar plantations has not significantly changed over the last two decades despite policy incentives to produce bioenergy crops. The current surface area of isoprene emitting poplars-for-bioenergy remains too limited to significantly enhance O3 concentrations and thus to be considered a potential threat for air quality and human health. PMID:27615148

  14. Effect of poplar genotypes on mycorrhizal infection and secreted enzyme activities in mycorrhizal and non-mycorrhizal roots

    PubMed Central

    Courty, P. E.; Labbé, J.; Kohler, A.; Marçais, B.; Bastien, C.; Churin, J. L.; Garbaye, J.; Le Tacon, F.

    2011-01-01

    The impact of ectomycorrhiza formation on the secretion of exoenzymes by the host plant and the symbiont is unknown. Thirty-eight F1 individuals from an interspecific Populus deltoides (Bartr.)×Populus trichocarpa (Torr. & A. Gray) controlled cross were inoculated with the ectomycorrhizal fungus Laccaria bicolor. The colonization of poplar roots by L. bicolor dramatically modified their ability to secrete enzymes involved in organic matter breakdown or organic phosphorus mobilization, such as N-acetylglucosaminidase, β-glucuronidase, cellobiohydrolase, β-glucosidase, β-xylosidase, laccase, and acid phosphatase. The expression of genes coding for laccase, N-acetylglucosaminidase, and acid phosphatase was studied in mycorrhizal and non-mycorrhizal root tips. Depending on the genes, their expression was regulated upon symbiosis development. Moreover, it appears that poplar laccases or phosphatases contribute poorly to ectomycorrhiza metabolic activity. Enzymes secreted by poplar roots were added to or substituted by enzymes secreted by L. bicolor. The enzymatic activities expressed in mycorrhizal roots differed significantly between the two parents, while it did not differ in non-mycorrhizal roots. Significant differences were found between poplar genotypes for all enzymatic activities measured on ectomycorrhizas except for laccases activity. In contrast, no significant differences were found between poplar genotypes for enzymatic activities of non-mycorrhizal root tips except for acid phosphatase activity. The level of enzymes secreted by the ectomycorrhizal root tips is under the genetic control of the host. Moreover, poplar heterosis was expressed through the enzymatic activities of the fungal partner. PMID:20881013

  15. Effect of clonal variation among hybrid poplars on susceptibility of gypsy moth (Lepidoptera: Lymantriidae) to Bacillus thuringiensis subsp. kurstaki.

    PubMed

    Broderick, Nichole A; Vasquez, Eric; Handelsman, Jo; Raffa, Kenneth F

    2010-06-01

    Trees in the genus Populus can provide substantial commercial and ecological benefits, including sustainable alternatives to traditional forestry. Realization of this potential requires intensive management, but damage by defoliating insects can severely limit productivity in such systems. Two approaches to limiting these losses include cultivation of poplar varieties with inherent resistance to pests and application of microbial pesticides. Little is known about the interaction between host resistance and the ability of poplars to support the efficacy of biocontrol agents. The research described here was conducted to survey the effect of hybrid poplar clones on gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), a pest on these trees. We assessed the effect of various poplar clones on larval performance and susceptibility to Bacillus thuringiensis subsp. kurstaki. Larvae were reared from hatching on the foliage of 25 hybrid poplar clones and we monitored larval survival, development time, and weight at fourth instar. Eight of these clones showed high resistance against gypsy moth. The remaining clones showed high variation in their effect on larval performance. We evaluated the susceptibility of third-instar larvae to B. thuringiensis subsp. kurstaki when reared on the 17 remaining clones. There was a significant effect of poplar clone on time to death after ingestion of B. thuringiensis subsp. kurstaki. The susceptibility of gypsy moth larvae to B. thuringiensis on various clones was not correlated with the effects of these clones on larval performance in the absence of B. thuringiensis, suggesting this interaction is more complex than merely reflecting higher mortality to previously stressed larvae.

  16. Interaction between isoprene and ozone fluxes in a poplar plantation and its impact on air quality at the European level

    PubMed Central

    Zenone, Terenzio; Hendriks, Carlijn; Brilli, Federico; Fransen, Erik; Gioli, Beniamio; Portillo-Estrada, Miguel; Schaap, Martijn; Ceulemans, Reinhart

    2016-01-01

    The emission of isoprene and other biogenic volatile organic compounds from vegetation plays an important role in tropospheric ozone (O3) formation. The potentially large expansion of isoprene emitting species (e.g., poplars) for bioenergy production might, therefore, impact tropospheric O3 formation. Using the eddy covariance technique we have simultaneously measured fluxes isoprene, O3 and of CO2 from a poplar (Populus) plantation grown for bioenergy production. We used the chemistry transport model LOTOS-EUROS to scale-up the isoprene emissions associated with the existing poplar plantations in Europe, and we assessed the impact of isoprene fluxes on ground level O3 concentrations. Our findings suggest that isoprene emissions from existing poplar-for-bioenergy plantations do not significantly affect the ground level of O3 concentration. Indeed the overall land in Europe covered with poplar plantations has not significantly changed over the last two decades despite policy incentives to produce bioenergy crops. The current surface area of isoprene emitting poplars-for-bioenergy remains too limited to significantly enhance O3 concentrations and thus to be considered a potential threat for air quality and human health. PMID:27615148

  17. Transgenic mouse offspring generated by ROSI

    PubMed Central

    MOREIRA, Pedro; PÉREZ-CEREZALES, Serafín; LAGUNA, Ricardo; FERNÁNDEZ-GONZALEZ, Raúl; SANJUANBENITO, Belén Pintado; GUTIÉRREZ-ADÁN, Alfonso

    2015-01-01

    The production of transgenic animals is an important tool for experimental and applied biology. Over the years, many approaches for the production of transgenic animals have been tried, including pronuclear microinjection, sperm-mediated gene transfer, transfection of male germ cells, somatic cell nuclear transfer and the use of lentiviral vectors. In the present study, we developed a new transgene delivery approach, and we report for the first time the production of transgenic animals by co-injection of DNA and round spermatid nuclei into non-fertilized mouse oocytes (ROSI). The transgene used was a construct containing the human CMV immediate early promoter and the enhanced GFP gene. With this procedure, 12% of the live offspring we obtained carried the transgene. This efficiency of transgenic production by ROSI was similar to the efficiency by pronuclear injection or intracytoplasmic injection of male gamete nuclei (ICSI). However, ICSI required fewer embryos to produce the same number of transgenic animals. The expression of Egfp mRNA and fluorescence of EGFP were found in the majority of the organs examined in 4 transgenic lines generated by ROSI. Tissue morphology and transgene expression were not distinguishable between transgenic animals produced by ROSI or pronuclear injection. Furthermore, our results are of particular interest because they indicate that the transgene incorporation mediated by intracytoplasmic injection of male gamete nuclei is not an exclusive property of mature sperm cell nuclei with compact chromatin but it can be accomplished with immature sperm cell nuclei with decondensed chromatin as well. The present study also provides alternative procedures for transgene delivery into embryos or reconstituted oocytes. PMID:26498042

  18. Exploring the Role of Plant Genetics to Enhance Soil Carbon Sequestration in Hybrid Poplar Plantations

    NASA Astrophysics Data System (ADS)

    Wullschleger, S. D.; Garten, C. T.; Classen, A. T.

    2008-12-01

    Atmospheric CO2 concentrations have increased in recent decades and are projected to increase even further during the coming century. These projections have prompted scientists and policy-makers to consider how plants and soils can be used to stabilize CO2 concentrations. Although storing carbon in terrestrial ecosystems represents an attractive near-term option for mitigating rising atmospheric CO2 concentrations, enhancing the sequestration potential of managed systems will require advancements in understanding the fundamental mechanisms that control rates of carbon transfer and turnover in plants and soils. To address this challenge, a mathematical model was constructed to evaluate how changes in particular plant traits and management practices could affect soil carbon storage beneath hybrid poplar (Populus) plantations. The model was built from four sub-models that describe aboveground biomass, root biomass, soil carbon dynamics, and soil nitrogen transformations for trees growing throughout a user-defined rotation. Simulations could be run over one or multiple rotations. A sensitivity analysis of the model indicated changes in soil carbon storage were affected by variables that could be linked to hybrid poplar traits like rates of aboveground production, partitioning of carbon to coarse and fine roots, and rates of root decomposition. A higher ratio of belowground to aboveground production was especially important and correlated directly with increased soil carbon storage. Faster decomposition rates for coarse and fine dead roots resulted in a greater loss of carbon to the atmosphere as CO2 and less residual organic carbon for transfer to the fast soil carbon pool. Hence, changes in root chemistry that prolonged dead root decomposition rates, a trait that is under potential genetic control, were predicted to increase soil carbon storage via higher soil carbon inputs. Nitrogen limitation of both aboveground biomass production and soil carbon sequestration was

  19. Strontium isotope detection of brine contamination in the East Poplar oil field, Montana

    USGS Publications Warehouse

    Peterman, Zell E.; Thamke, Joanna N.; Futa, Kiyoto; Oliver, Thomas A.

    2010-01-01

    Brine contamination of groundwater in the East Poplar oil field was first documented in the mid-1980s by the U.S. Geological Survey by using hydrochemistry, with an emphasis on chloride (Cl) and total dissolved solids concentrations. Supply wells for the City of Poplar are located downgradient from the oil field, are completed in the same shallow aquifers that are documented as contaminated, and therefore are potentially at risk of being contaminated. In cooperation with the Office of Environmental Protection of the Fort Peck Tribes, groundwater samples were collected in 2009 and 2010 from supply wells, monitor wells, and the Poplar River for analyses of major and trace elements, including strontium (Sr) concentrations and isotopic compositions. The ratio of strontium-87 to strontium-86 (87Sr/86Sr) is used extensively as a natural tracer in groundwater to detect mixing among waters from different sources and to study the effects of water/rock interaction. On a plot of the reciprocal strontium concentration against the 87Sr/86Sr ratio, mixtures of two end members will produce a linear array. Using this plotting method, data for samples from most of the wells, including the City of Poplar wells, define an array with reciprocal strontium values ranging from 0.08 to 4.15 and 87Sr/86Sr ratios ranging from 0.70811 to 0.70828. This array is composed of a brine end member with an average 87Sr/86Sr of 0.70822, strontium concentrations in excess of 12.5 milligrams per liter (mg/L), and chloride concentrations exceeding 8,000 mg/L mixing with uncontaminated water similar to that in USGS06-08 with 18.0 mg/L chloride, 0.24 mg/L strontium, and a 87Sr/86Sr ratio of 0.70811. The position of samples from the City of Poplar public-water supply wells within this array indicates that brine contamination has reached all three wells. Outliers from this array are EPU-4G (groundwater from the Cretaceous Judith River Formation), brine samples from disposal wells (Huber 5-D and EPU 1-D

  20. Polyhydroxybutyrate synthesis in transgenic flax.

    PubMed

    Wróbel, Magdalena; Zebrowski, Jacek; Szopa, Jan

    2004-01-01

    Flax (Linum usitatissimum L.) is an annual plant species widely cultivated in temperate climates for bast fibres and linseed oil. Apart from traditional textile use, the fibres are fast becoming an integral part of new composite materials utilized in automobile and constructive industry. Especially attractive for environmental safety demands are biodegradable and renewable biocomposities based on polyhydroxybutyrate (PHB) polymer as a matrix and reinforced with the flax fibres. Manufacturing of PHB by bacteria fermentation is however substantially more expansive as compared to technologies producing conventional plastics. We report for the first time generation of transgenic plants which produce both components of flax/PHB composites, i.e. the fibres and the thermoplastic matrix in the same plant organ of a crop. The flax (cv. Nike) plants were transformed using constructs bearing either single cDNA, encoding the beta-ketothiolase enzyme (C plants), or all three of the genes necessary for poly-beta-hydroxybutyrate (PHB) synthesis (M plants). Both constructs contained a plastidial targeting sequence. The amount of PHB produced by the transgenic plants was up to over 70-fold higher than in wild-type plants, when analysed using the gas chromatography/mass spectrometry (GC-MS method). The PHB accumulation in plastids caused change both in their shape and size. The use of a stem-specific promoter for transgene expression protected the transgenic plant from growth retardation and also provided higher PHB synthesis than in the case of constructs governed by the 35S CaMV constitutive promoter. None toxic effects that could lead to stunted growth or the loss of fertility were observed, when 14-3-3 promoter was used as the stem-specific. Significant modifications in stem mechanical properties were accompanied to the PHB accumulation in growing cell of fibres in the transgenic plants. The Young's modulus E, the average measure of stem tissues resistance to tensile loads

  1. Biological Monitoring Program for East Fork Poplar Creek

    SciTech Connect

    Adams, S.M.; Christensen, S.W.; Greeley, M.S.jr; Hill, W.R.; Kszos, L.A.; McCarthy, J.F.; Peterson, M.J.; Ryon, M.G.; Smith, J.G.; Southworth, G.R.; Stewart, A.J.

    1998-10-15

    In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit, a Biologicai Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the compiex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity of EFPC, These tasks are (1) toxicity monitoring, (2) biological indicator studies, (3) bioaccumuiation studies, and (4) ecological surveys of the periphyton, benthic macro invertebrate, and fish communities. Monitoring is currently being conducted at five sites, although sites maybe excluded and/or others added depending upon the specific objectives of the various tasks. Criteria used in selecting the sites include: (1) location of sampling sites used in other studies, (2) known or suspected sources of downstream impacts, (3) proximity to U.S. Department of Energy (DOE) Oak Ridge Reservation (ORR) boundaries, (4) concentration of mercury in the adjacent floodplain, (5) appropriate habitat distribution, and (6

  2. Reversible swelling of the cell wall of poplar biomass by ionic liquid at room temperature

    PubMed Central

    Lucas, Marcel; Wagner, Greg L.; Nishiyama, Yoshiharu; Hanson, Leif; Samayam, Indira P.; Schall, Constance A.; Langan, Paul; Rector, Kirk D.

    2012-01-01

    Time-resolved autofluorescence, Raman microspectroscopy, and scanning microprobe X-ray diffraction were combined in order to characterize lignocellulosic biomass from poplar trees and how it changes during treatment with the ionic liquid 1-n-ethyl-3-methylimidazolium acetate (EMIMAC) at room temperature. The EMIMAC penetrates the cell wall from the lumen, swelling the cell wall by about a factor of two towards the empty lumen. However, the middle lamella remains unchanged, preventing the cell wall from swelling outwards. During this swelling, most of the cellulose microfibrils are solubi-lized but chain migration is restricted and a small percentage of microfibrils persist. When the EMIMAC is expelled, the cellulose recrystallizes as microfibrils of cellulose I. There is little change in the relative chemical composition of the cell wall after treatment. The action of EMIMAC on the poplar cell wall at room temperature would therefore appear to be a reversible swelling and a reversible decrystallization of the cell wall. PMID:21247757

  3. Engineering functional artificial hybrid proteins between poplar peroxiredoxin II and glutaredoxin or thioredoxin

    SciTech Connect

    Rouhier, Nicolas . E-mail: nrouhier@scbiol.uhp-nancy.fr; Gama, Filipe; Wingsle, Gunnar; Gelhaye, Eric; Gans, Pierre; Jacquot, Jean-Pierre

    2006-03-24

    The existence of natural peroxiredoxin-glutaredoxin hybrid enzymes in several bacteria is in line with previous findings indicating that poplar peroxiredoxin II can use glutaredoxin as an electron donor. This peroxiredoxin remains however unique since it also uses thioredoxin with a quite good efficiency. Based on the existing fusions, we have created artificial enzymes containing a poplar peroxiredoxin module linked to glutaredoxin or thioredoxin modules. The recombinant fusion enzymes folded properly into non-covalently bound homodimers or homotetramers. Two of the three protein constructs exhibit peroxidase activity, a reaction where the two modules need to function together, but they also display enzymatic activities specific of each module. In addition, mass spectrometry analyses indicate that the Prx module can be both glutathiolated or overoxidized in vitro. This is discussed in the light of the Prx reactivity.

  4. Cometabolic degradation of trichloroethylene by Burkholderia cepacia G4 with poplar leaf homogenate.

    PubMed

    Kang, Jun Won; Doty, Sharon Lafferty

    2014-07-01

    Trichloroethylene (TCE), a chlorinated organic solvent, is one of the most common and widespread groundwater contaminants worldwide. Among the group of TCE-degrading aerobic bacteria, Burkholderia cepacia G4 is the best-known representative. This strain requires the addition of specific substrates, including toluene, phenol, and benzene, to induce the enzymes to degrade TCE. However, the substrates are toxic and introducing them into the soil can result in secondary contamination. In this study, poplar leaf homogenate containing natural phenolic compounds was tested for the ability to induce the growth of and TCE degradation by B. cepacia G4. The results showed that the G4 strain could grow and degrade TCE well with the addition of phytochemicals. The poplar leaf homogenate also functioned as an inducer of the toluene-ortho-monooxygenase (TOM) gene in B. cepacia G4.

  5. Feasibility study of transportation management strategies in the Poplar Corridor, Memphis, Tennessee

    SciTech Connect

    Siniard, D.

    1990-02-01

    This report documents the development and implementation of various transportation management strategies aimed at alleviating traffic congestion problems in the Poplar Corridor, a major transportation corridor located in a rapidly growing suburban area of Memphis, Tennessee. The project provided the opportunity for local governments to work with the private sector in a joint venture to address traffic congestion problems and to promote more efficient use of the area's transportation network. The project was carried out by the staff of Memphis Area Rideshare, a joint city/county agency which provides transit information and free carpool/vanpool computer matching services to area commuters. Public sector participants in the planning process included transportation and land use planners from the Office of Planning and Development, city traffic engineers, and representatives from the Memphis Area Transit Authority (MATA). Private sector input came from major developers and employers in the Poplar Corridor and from officials of schools located in the area.

  6. Predictive relationships for uptake of organic contaminants by hybrid poplar trees

    SciTech Connect

    Burken, J.G.; Schnoor, J.L.

    1998-11-01

    Twelve organic compounds commonly found at hazardous waste sites were studied for uptake by hybrid poplar trees. The vegetative uptake of many of these compounds has not previously been demonstrated for plant species being utilized for phytoremediation, such as hybrid poplar trees. Experiments were conducted hydroponically utilizing {sup 14}C-labeled compounds to ascertain translocation and fate. Predictive relationships for the translocation and partitioning to plant tissues were developed from the experimental data. Translocation and partitioning relationships based on compounds` octanol-water partitioning coefficients produced the best results, but the relationships did not allow for fully accurate prediction of each contaminant`s fate. Translocation and subsequent transpiration of volatile organic compounds (VOCs) from the leaves to the atmosphere was shown to be a significant pathway. As full-scale phytoremediation systems are deliberated, the pathways investigated here should be considered in terms of a contaminant removal mechanism and potential contamination of the vegetation.

  7. Partial acid hydrolysis of poplar wood as a pretreatment for enzymatic hydrolysis

    SciTech Connect

    Knappert, D.; Grethlein, H.; Converse, A.

    1981-01-01

    Partial acid hydrolysis was studied as a pretreatment to enhance glucose yields from enzymatic hydrolysis of poplar. The pretreatments were carried out in a continuous flow reactor at temperatures ranging from 162 to 222/sup 0/C, acid concentrations ranging from 0 to 1.5%, and treatment times from 3.6 to 12.7 s. The pretreated slurries were hydrolyzed with Trichoderma reesei C30 cellulase at 50/sup 0/C and a pH of 4.8 for 48 h. Increased yields of glucose were achieved when poplar was pretreated at temperatures higher than 180/sup 0/C. By increasing the cellobiase activity of the cellulase with the addition of NOVO cellobiase, in some cases 100% of the potential glucose content of the substrate was converted to glucose after only 24 h of enzymatic hydrolysis.

  8. Dynamics of the volatile defense of winter "dormant" balsam poplar (Populus balsamifera).

    PubMed

    Clausen, Thomas P; Chen, Janice; Bryant, John P; Provenza, Frederick D; Villalba, Juan

    2010-05-01

    6-Hydroxycylohex-2-en-1-one (6-HCH) has been reported as a major chemical defense of the winter-dormant internodes of balsam poplar (Populus balsamifera) against feeding by herbivores such as the snowshoe hare (Lepus americanus). We report that the concentration of 6-HCH in the fall internodes is triggered by a single hard frost, and then undergoes an exponential decline through volatilization over the winter that results in barely detectable quantities by early spring. We conclude that the role of 6-HCH in the defense of mature balsam poplar is more complex than simply acting as a toxin. Rather, 6-HCH's role as a defensive agent must evolve over the course of the winter from being a co-toxin to a cue for a conditioned flavor aversion (CFA) to finally having no role by late spring.

  9. Effects of cutting orientation in poplar wood biomass size reduction on enzymatic hydrolysis sugar yield.

    PubMed

    Zhang, Meng; Ju, Xiaohui; Song, Xiaoxu; Zhang, Xiao; Pei, Z J; Wang, Donghai

    2015-10-01

    The aim of this study was to understand how cutting orientation in poplar wood biomass size reduction affects enzymatic hydrolysis sugar yield of wood particles. A metal cutting (milling) machine was used to produce poplar wood particles from three cutting orientations. Results showed that cutting orientation significantly affected enzymatic hydrolysis sugar yield of wood particles. In this study, size reduction from the optimum cutting orientation produced 50% more sugars than the other two cutting orientations. Particles from the cutting orientation with the highest sugar yield had a large enzyme accessible area (125 mg orange dye/g biomass, as evaluated by Simons' stain procedure) and low crystallinity (50% crystallinity index, as calculated by the Segal method). Furthermore, small particle size did not necessarily lead to improvement in enzymatic digestibility.

  10. Transgene integration: use of matrix attachment regions.

    PubMed

    Allen, George C; Spiker, Steven; Thompson, William F

    2005-01-01

    Matrix attachment regions (MARs) are operationally defined as DNA elements that bind specifically to the nuclear matrix in vitro. When MARs are positioned at the 5'- and 3'-ends of a transgene higher more predictable expression of the transgene results. MARs are increasingly being applied to prevent unwanted transgene silencing, which is especially common when direct DNA transformation methods are used. This chapter describes methods for the isolation of MARs and the subsequent methods allowing the investigator to incorporate MARS into transformation strategies that can both improve transformation frequency and result in predictable, stable expression of the transgenic trait.

  11. Transgene integration: use of matrix attachment regions.

    PubMed

    Allen, George C; Spiker, Steven; Thompson, William F

    2005-01-01

    Matrix attachment regions (MARs) are operationally defined as DNA elements that bind specifically to the nuclear matrix in vitro. When MARs are positioned at the 5'- and 3'-ends of a transgene higher more predictable expression of the transgene results. MARs are increasingly being applied to prevent unwanted transgene silencing, which is especially common when direct DNA transformation methods are used. This chapter describes methods for the isolation of MARs and the subsequent methods allowing the investigator to incorporate MARS into transformation strategies that can both improve transformation frequency and result in predictable, stable expression of the transgenic trait. PMID:15310930

  12. [The safety and usefulness of transgenic plants].

    PubMed

    Ondrej, M; Drobník, M

    1997-05-29

    Transgenic crop plants, used in food and feed production, carry different beneficial transgenes, mostly for resistance to pests, herbicides and diseases. All new transgenic plant varieties, the genes they carry and their products have been thoroughly tested before released for agriculture and even more for marketing. Genetically modified organisms carry the same risk as any other organism. Food derived from genetically modified organisms due to legal regulation is most controlled and therefore most safe food ever placed on the market. In future, transgenic plants offer many new possibilities also for medical use, like plant vaccines, antibiotics and rare proteins of clinical importance produced by plants.

  13. Recent Y chromosome divergence despite ancient origin of dioecy in poplars (Populus).

    PubMed

    Geraldes, A; Hefer, C A; Capron, A; Kolosova, N; Martinez-Nuñez, F; Soolanayakanahally, R Y; Stanton, B; Guy, R D; Mansfield, S D; Douglas, C J; Cronk, Q C B

    2015-07-01

    All species of the genus Populus (poplar, aspen) are dioecious, suggesting an ancient origin of this trait. Despite some empirical counter examples, theory suggests that nonrecombining sex-linked regions should quickly spread, eventually becoming heteromorphic chromosomes. In contrast, we show using whole-genome scans that the sex-associated region in Populus trichocarpa is small and much younger than the age of the genus. This indicates that sex determination is highly labile in poplar, consistent with recent evidence of 'turnover' of sex-determination regions in animals. We performed whole-genome resequencing of 52 P. trichocarpa (black cottonwood) and 34 Populus balsamifera (balsam poplar) individuals of known sex. Genomewide association studies in these unstructured populations identified 650 SNPs significantly associated with sex. We estimate the size of the sex-linked region to be ~100 kbp. All SNPs significantly associated with sex were in strong linkage disequilibrium despite the fact that they were mapped to six different chromosomes (plus 3 unmapped scaffolds) in version 2.2 of the reference genome. We show that this is likely due to genome misassembly. The segregation pattern of sex-associated SNPs revealed this to be an XY sex-determining system. Estimated divergence times of X and Y haplotype sequences (6-7 Ma) are much more recent than the divergence of P. trichocarpa (poplar) and Populus tremuloides (aspen). Consistent with this, in P. tremuloides, we found no XY haplotype divergence within the P. trichocarpa sex-determining region. These two species therefore have a different genomic architecture of sex, suggestive of at least one turnover event in the recent past.

  14. Characterization of the Poplar Pan-Genome by Genome-Wide Identification of Structural Variation.

    PubMed

    Pinosio, Sara; Giacomello, Stefania; Faivre-Rampant, Patricia; Taylor, Gail; Jorge, Veronique; Le Paslier, Marie Christine; Zaina, Giusi; Bastien, Catherine; Cattonaro, Federica; Marroni, Fabio; Morgante, Michele

    2016-10-01

    Many recent studies have emphasized the important role of structural variation (SV) in determining human genetic and phenotypic variation. In plants, studies aimed at elucidating the extent of SV are still in their infancy. Evidence has indicated a high presence and an active role of SV in driving plant genome evolution in different plant species.With the aim of characterizing the size and the composition of the poplar pan-genome, we performed a genome-wide analysis of structural variation in three intercrossable poplar species: Populus nigra, Populus deltoides, and Populus trichocarpa We detected a total of 7,889 deletions and 10,586 insertions relative to the P. trichocarpa reference genome, covering respectively 33.2 Mb and 62.9 Mb of genomic sequence, and 3,230 genes affected by copy number variation (CNV). The majority of the detected variants are inter-specific in agreement with a recent origin following separation of species.Insertions and deletions (INDELs) were preferentially located in low-gene density regions of the poplar genome and were, for the majority, associated with the activity of transposable elements. Genes affected by SV showed lower-than-average expression levels and higher levels of dN/dS, suggesting that they are subject to relaxed selective pressure or correspond to pseudogenes.Functional annotation of genes affected by INDELs showed over-representation of categories associated with transposable elements activity, while genes affected by genic CNVs showed enrichment in categories related to resistance to stress and pathogens. This study provides a genome-wide catalogue of SV and the first insight on functional and structural properties of the poplar pan-genome. PMID:27499133

  15. Characterization of the Poplar Pan-Genome by Genome-Wide Identification of Structural Variation

    PubMed Central

    Pinosio, Sara; Giacomello, Stefania; Faivre-Rampant, Patricia; Taylor, Gail; Jorge, Veronique; Le Paslier, Marie Christine; Zaina, Giusi; Bastien, Catherine; Cattonaro, Federica; Marroni, Fabio; Morgante, Michele

    2016-01-01

    Many recent studies have emphasized the important role of structural variation (SV) in determining human genetic and phenotypic variation. In plants, studies aimed at elucidating the extent of SV are still in their infancy. Evidence has indicated a high presence and an active role of SV in driving plant genome evolution in different plant species. With the aim of characterizing the size and the composition of the poplar pan-genome, we performed a genome-wide analysis of structural variation in three intercrossable poplar species: Populus nigra, Populus deltoides, and Populus trichocarpa. We detected a total of 7,889 deletions and 10,586 insertions relative to the P. trichocarpa reference genome, covering respectively 33.2 Mb and 62.9 Mb of genomic sequence, and 3,230 genes affected by copy number variation (CNV). The majority of the detected variants are inter-specific in agreement with a recent origin following separation of species. Insertions and deletions (INDELs) were preferentially located in low-gene density regions of the poplar genome and were, for the majority, associated with the activity of transposable elements. Genes affected by SV showed lower-than-average expression levels and higher levels of dN/dS, suggesting that they are subject to relaxed selective pressure or correspond to pseudogenes. Functional annotation of genes affected by INDELs showed over-representation of categories associated with transposable elements activity, while genes affected by genic CNVs showed enrichment in categories related to resistance to stress and pathogens. This study provides a genome-wide catalogue of SV and the first insight on functional and structural properties of the poplar pan-genome. PMID:27499133

  16. Influence of moisture content on the velocity of ultrasounds in black poplar wood

    NASA Technical Reports Server (NTRS)

    Bucar, V.; Facacaru, I.

    1974-01-01

    Correlations among the longitudinal, radial and tangential velocities of ultrasounds in black poplar on the one hand and among these magnitudes and the wood's moisture content on the other hand are presented. Mathematical equations approximating these correlations are given, and the influence of moisture content on the elastic constants of wood is discussed. The possibility of using ultrasonic methods in automating the wood drying process and in testing the quality and homogeneity of wood is pointed out.

  17. A built-in strategy for containment of transgenic plants: creation of selectively terminable transgenic rice.

    PubMed

    Lin, Chaoyang; Fang, Jun; Xu, Xiaoli; Zhao, Te; Cheng, Jiaan; Tu, Juming; Ye, Gongyin; Shen, Zhicheng

    2008-01-01

    Plant transgenic technology has been widely utilized for engineering crops for trait improvements and for production of high value proteins such as pharmaceuticals. However, the unintended spreading of commercial transgenic crops by pollination and seed dispersal is a major concern for environmental and food safety. Simple and reliable containment strategies for transgenes are highly desirable. Here we report a novel method for creating selectively terminable transgenic rice. In this method, the gene(s) of interest is tagged with a RNA interference cassette, which specifically suppresses the expression of the bentazon detoxification enzyme CYP81A6 and thus renders transgenic rice to be sensitive to bentazon, a herbicide used for rice weed control. We generated transgenic rice plants by this method using a new glyphosate resistant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene from Pesudomonas putida as the gene of interest, and demonstrated that these transgenic rice plants were highly sensitive to bentazon but tolerant to glyphosate, which is exactly the opposite of conventional rice. Field trial of these transgenic rice plants further confirmed that they can be selectively killed at 100% by one spray of bentazon at a regular dose used for conventional rice weed control. Furthermore, we found that the terminable transgenic rice created in this study shows no difference in growth, development and yield compared to its non-transgenic control. Therefore, this method of creating transgenic rice constitutes a novel strategy of transgene containment, which appears simple, reliable and inexpensive for implementation. PMID:18350155

  18. A Built-In Strategy for Containment of Transgenic Plants: Creation of Selectively Terminable Transgenic Rice

    PubMed Central

    Zhao, Te; Cheng, Jiaan; Tu, Juming; Ye, Gongyin; Shen, Zhicheng

    2008-01-01

    Plant transgenic technology has been widely utilized for engineering crops for trait improvements and for production of high value proteins such as pharmaceuticals. However, the unintended spreading of commercial transgenic crops by pollination and seed dispersal is a major concern for environmental and food safety. Simple and reliable containment strategies for transgenes are highly desirable. Here we report a novel method for creating selectively terminable transgenic rice. In this method, the gene(s) of interest is tagged with a RNA interference cassette, which specifically suppresses the expression of the bentazon detoxification enzyme CYP81A6 and thus renders transgenic rice to be sensitive to bentazon, a herbicide used for rice weed control. We generated transgenic rice plants by this method using a new glyphosate resistant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene from Pesudomonas putida as the gene of interest, and demonstrated that these transgenic rice plants were highly sensitive to bentazon but tolerant to glyphosate, which is exactly the opposite of conventional rice. Field trial of these transgenic rice plants further confirmed that they can be selectively killed at 100% by one spray of bentazon at a regular dose used for conventional rice weed control. Furthermore, we found that the terminable transgenic rice created in this study shows no difference in growth, development and yield compared to its non-transgenic control. Therefore, this method of creating transgenic rice constitutes a novel strategy of transgene containment, which appears simple, reliable and inexpensive for implementation. PMID:18350155

  19. A built-in strategy for containment of transgenic plants: creation of selectively terminable transgenic rice.

    PubMed

    Lin, Chaoyang; Fang, Jun; Xu, Xiaoli; Zhao, Te; Cheng, Jiaan; Tu, Juming; Ye, Gongyin; Shen, Zhicheng

    2008-01-01

    Plant transgenic technology has been widely utilized for engineering crops for trait improvements and for production of high value proteins such as pharmaceuticals. However, the unintended spreading of commercial transgenic crops by pollination and seed dispersal is a major concern for environmental and food safety. Simple and reliable containment strategies for transgenes are highly desirable. Here we report a novel method for creating selectively terminable transgenic rice. In this method, the gene(s) of interest is tagged with a RNA interference cassette, which specifically suppresses the expression of the bentazon detoxification enzyme CYP81A6 and thus renders transgenic rice to be sensitive to bentazon, a herbicide used for rice weed control. We generated transgenic rice plants by this method using a new glyphosate resistant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene from Pesudomonas putida as the gene of interest, and demonstrated that these transgenic rice plants were highly sensitive to bentazon but tolerant to glyphosate, which is exactly the opposite of conventional rice. Field trial of these transgenic rice plants further confirmed that they can be selectively killed at 100% by one spray of bentazon at a regular dose used for conventional rice weed control. Furthermore, we found that the terminable transgenic rice created in this study shows no difference in growth, development and yield compared to its non-transgenic control. Therefore, this method of creating transgenic rice constitutes a novel strategy of transgene containment, which appears simple, reliable and inexpensive for implementation.

  20. Assessing the use of poplar tree systems as a landfill evapotranspiration barrier with the SHAW model.

    PubMed

    Preston, G M; McBride, R A

    2004-08-01

    The use of poplar tree systems (PTS) as evapotranspiration barriers on decommissioned landfills is gaining attention as an option for leachate management. This study involved field-testing the Simultaneous Heat and Water (SHAW) model for its ability to reliably estimate poplar transpiration, volumetric soil water content, and soil temperature at a landfill located in southern Ontario, Canada. The model was then used to estimate deep drainage and to ascertain the influence of a young PTS on the soil water balance of the landfill cover. The SHAW model tended to underestimate poplar transpiration [mean difference (MD) ranged from 0.33 to 3.55 mm on a daily total basis] and overestimate volumetric soil water content by up to 0.10 m3 m(-3). The model estimated soil temperature very well, particularly in the upper 1 m of the landfill cover (MD ranged from -0.1 to 1.6 x degrees C in this layer). The SHAW model simulations showed that deep drainage decreased appreciably with the presence of a young PTS largely through increased interception of rainfall, and that PTS have a good potential to act as effective evapotranspiration barriers in northern temperate climate zones. PMID:15462337

  1. Water consumption and biomass production of protoplast fusion lines of poplar hybrids under drought stress.

    PubMed

    Hennig, Anne; Kleinschmit, Jörg R G; Schoneberg, Sebastian; Löffler, Sonja; Janßen, Alwin; Polle, Andrea

    2015-01-01

    Woody crops such as poplars (Populus) can contribute to meet the increasing energy demand of a growing human population and can therefore enhance the security of energy supply. Using energy from biomass increases ecological sustainability as biomass is considered to play a pivotal role in abating climate change. Because areas for establishing poplar plantations are often confined to marginal sites drought tolerance is one important trait for poplar genotypes cultivated in short rotation coppice. We tested 9-month-old plants of four tetraploid Populus tremula (L.) × P. tremuloides (Michx.) lines that were generated by protoplast fusion and their diploid counterpart for water consumption and drought stress responses in a greenhouse experiment. The fusion lines showed equivalent or decreased height growth, stem biomass and total leaf area compared to the diploid line. The relative height increment of the fusion lines was not reduced compared to the diploid line when the plants were exposed to drought. The fusion lines were distinguished from the diploid counterpart by stomatal characteristics such as increased size and lower density. The changes in the stomatal apparatus did not affect the stomatal conductance. When exposed to drought the carbohydrate concentrations increased more strongly in the fusion lines than in the diploid line. Two fusion lines consumed significantly less water with regard to height growth, producing equivalent or increased relative stem biomass under drought compared to their diploid relative. Therefore, these tetraploid fusion lines are interesting candidates for short rotation biomass plantation on dry sites. PMID:26042130

  2. Water stress induces changes in polyphenol profile and antioxidant capacity in poplar plants (Populus spp.).

    PubMed

    Popović, B M; Štajner, D; Ždero-Pavlović, R; Tumbas-Šaponjac, V; Čanadanović-Brunet, J; Orlović, S

    2016-08-01

    This paper is aimed to characterize young poplar plants under the influence of water stress provoked by polyethileneglycol 6000 (PEG 6000). Three polar genotypes (M1, B229, and PE19/66) were grown in hydroponics and subjected to 100 and 200 mOsm PEG 6000 during six days. Polyphenol characterization, two enzymatic markers and antioxidant capacity in leaves and roots were investigated in stressed plants. Total phenol content, ferric reducing antioxidant capacity (FRAP) and DPPH antiradical power (DPPH ARP) were determined for estimating total antioxidant capacity. Polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were determined as enzymatic markers. Polyphenol characterization of poplar samples was performed by HPLC-PDA analysis. All results were subjected to correlation analysis and principal component analysis (PCA). Inspite of the decrease of total phenol content in investigated genotypes, as well as total antioxidant capacity, some of polyphenols were affected by stress like flavonoids chrysin, myricetine, kaempferol and isoferulic acid in roots of B229 genotype (Populus deltoides). Genotype B229 also showed the increase of antioxidant capacity and PAL activity in root and leaves under stress what could be the indicator of the adaptability of poplar plants to water stress. Significant positive correlations were obtained between PAL, antioxidant capacity as well as phenolic acids among themselves. Chemometric evaluation showed close interdependence between flavonoids, FRAP, DPPH antiradical power and both investigated enzymes of polyphenol metabolism, PAL and PPO.

  3. Boron accumulation and toxicity in hybrid poplar (Populus nigra × euramericana).

    PubMed

    Rees, Rainer; Robinson, Brett H; Menon, Manoj; Lehmann, Eberhard; Günthardt-Goerg, Madeleine S; Schulin, Rainer

    2011-12-15

    Poplars accumulate high B concentrations and are thus used for the phytomanagement of B contaminated soils. Here, we performed pot experiments in which Populus nigra × euramericana were grown on a substrate with B concentrations ranging from 13 to 280 mg kg(-1) as H(3)BO(3). Salix viminalis, Brassica juncea, and Lupinus albus were grown under some growing conditions for comparison. Poplar growth was unaffected at soil B treatment levels up to 93 mg kg(-1). Growth was progressively reduced at levels of 168 and 280 mg kg(-1). None of the other species survived at these substrate B levels. At leaf B concentrations <900 mg kg(-1) only <10% of the poplar leaf area showed signs of toxicity. Neutron radiography revealed that chlorotic leaf tissues had B concentrations of 1000-2000 mg kg(-1), while necrotic tissues had >2000 mg kg(-1). Average B concentrations of up to 3500 mg kg(-1) were found in leaves, while spots within leaves had concentrations >7000 mg kg(-1), showing that B accumulation in leaf tissue continued even after the onset of necrosis. The B accumulation ability of P. nigra × euramericana is associated with B hypertolerance in the living tissue and storage of B in dead leaf tissue. PMID:22050628

  4. Investigating Mass Transport Limitations on Xylan Hydrolysis During Dilute Acid Pretreatment of Poplar

    SciTech Connect

    Mittal, Ashutosh; Pilath, Heid M.; Parent, Yves; Chatterjee, Siddharth G.; Donohoe, Bryon S.; Yarbrough, John M.; Himmel, Michael E.; Nimlos, Mark R.; Johnson, David K.

    2014-04-28

    Mass transport limitations could be an impediment to achieving high sugar yields during biomass pretreatment and thus be a critical factor in the economics of biofuels production. The objective of this work was to study the mass transfer restrictions imposed by the structure of biomass on the hydrolysis of xylan during dilute acid pretreatment of biomass. Mass transfer effects were studied by pretreating poplar wood at particle sizes ranging from 10 micrometers to 10 mm. This work showed a significant reduction in the rate of xylan hydrolysis in poplar when compared to the intrinsic rate of hydrolysis for isolated xylan that is possible in the absence of mass transfer. In poplar samples we observed no significant difference in the rates of xylan hydrolysis over more than two orders of magnitude in particle size. It appears that no additional mass transport restrictions are introduced by increasing particle size from 10 micrometers to 10 mm. This work suggests that the rates of xylan hydrolysis in biomass particles are limited primarily by the diffusion of hydrolysis products out of plant cell walls. A mathematical description is presented to describe the kinetics of xylan hydrolysis that includes transport of the hydrolysis products through biomass into the bulk solution. The modeling results show that the effective diffusion coefficient of the hydrolysis products in the cell wall is several orders of magnitude smaller than typical values in other applications signifying the role of plant cell walls in offering resistance to diffusion of the hydrolysis products.

  5. Water consumption and biomass production of protoplast fusion lines of poplar hybrids under drought stress.

    PubMed

    Hennig, Anne; Kleinschmit, Jörg R G; Schoneberg, Sebastian; Löffler, Sonja; Janßen, Alwin; Polle, Andrea

    2015-01-01

    Woody crops such as poplars (Populus) can contribute to meet the increasing energy demand of a growing human population and can therefore enhance the security of energy supply. Using energy from biomass increases ecological sustainability as biomass is considered to play a pivotal role in abating climate change. Because areas for establishing poplar plantations are often confined to marginal sites drought tolerance is one important trait for poplar genotypes cultivated in short rotation coppice. We tested 9-month-old plants of four tetraploid Populus tremula (L.) × P. tremuloides (Michx.) lines that were generated by protoplast fusion and their diploid counterpart for water consumption and drought stress responses in a greenhouse experiment. The fusion lines showed equivalent or decreased height growth, stem biomass and total leaf area compared to the diploid line. The relative height increment of the fusion lines was not reduced compared to the diploid line when the plants were exposed to drought. The fusion lines were distinguished from the diploid counterpart by stomatal characteristics such as increased size and lower density. The changes in the stomatal apparatus did not affect the stomatal conductance. When exposed to drought the carbohydrate concentrations increased more strongly in the fusion lines than in the diploid line. Two fusion lines consumed significantly less water with regard to height growth, producing equivalent or increased relative stem biomass under drought compared to their diploid relative. Therefore, these tetraploid fusion lines are interesting candidates for short rotation biomass plantation on dry sites.

  6. Yield and spatial supply of bioenergy poplar and willow short-rotation coppice in the UK.

    PubMed

    Aylott, Matthew J; Casella, E; Tubby, I; Street, N R; Smith, P; Taylor, Gail

    2008-01-01

    Limited information on likely supply and spatial yield of bioenergy crops exists for the UK. Here, productivities are reported of poplar (Populus spp.) and willow (Salix spp.) grown as short-rotation coppice (SRC), using data from a large 49-site yield trial network. A partial least-squares regression technique was used to upscale actual field trial observations across England and Wales. Spatial productivity was then assessed under different land-use scenarios. Mean modelled yields ranged between 4.9 and 10.7 oven-dry tonnes (odt) ha(-1) yr(-1). Yields were generally higher in willow than in poplar, reflecting the susceptibility of older poplar genotypes to rust and their tendency for single stem dominance. Replacing 10% of arable land, 20% of improved grassland and 100% of set-aside grassland in England and Wales with the three most productive genotypes would yield 13 Modt of biomass annually (supplying 7% of UK electricity production or 48% of UK combined heat and power (CHP) production). Results show existing SRC genotypes have the immediate potential to be an important component of a mixed portfolio of renewables and that, in future, as new and improved genotypes become available, higher yields could extend this potential further.

  7. Short rotation coppice culture of willows and poplars as energy crops on metal contaminated agricultural soils.

    PubMed

    Ruttens, Ann; Boulet, Jana; Weyens, Nele; Smeets, Karen; Adriaensen, Kristin; Meers, Erik; Van Slycken, Stijn; Tack, Filip; Meiresonne, Linda; Thewys, Theo; Witters, Nele; Carleer, Robert; Dupae, Joke; Vangronsveld, Jaco

    2011-01-01

    Phytoremediation, more precisely phytoextraction, has been placed forward as an environmental friendly remediation technique, that can gradually reduce increased soil metal concentrations, in particular the bioavailable fractions. The aim of this study was to investigate the possibilities of growing willows and poplars under short rotation coppice (SRC) on an acid, poor, sandy metal contaminated soil, to combine in this way soil remediation by phytoextraction on one hand, and production of biomass for energy purposes on the other. Above ground biomass productivities were low for poplars to moderate for willows, which was not surprising, taking into account the soil conditions that are not very favorable for growth of these trees. Calculated phytoextraction efficiency was much longer for poplars than these for willows. We calculated that for phytoextraction in this particular case it would take at least 36 years to reach the legal threshold values for cadmium, but in combination with production of feedstock for bioenergy processes, this type of land use can offer an alternative income for local farmers. Based on the data of the first growing cycle, for this particular case, SRC of willows should be recommended.

  8. Effector-Mining in the Poplar Rust Fungus Melampsora larici-populina Secretome

    PubMed Central

    Lorrain, Cécile; Hecker, Arnaud; Duplessis, Sébastien

    2015-01-01

    The poplar leaf rust fungus, Melampsora larici-populina has been established as a tree-microbe interaction model. Understanding the molecular mechanisms controlling infection by pathogens appears essential for durable management of tree plantations. In biotrophic plant-parasites, effectors are known to condition host cell colonization. Thus, investigation of candidate secreted effector proteins (CSEPs) is a major goal in the poplar–poplar rust interaction. Unlike oomycetes, fungal effectors do not share conserved motifs and candidate prediction relies on a set of a priori criteria established from reported bona fide effectors. Secretome prediction, genome-wide analysis of gene families and transcriptomics of M. larici-populina have led to catalogs of more than a thousand secreted proteins. Automatized effector-mining pipelines hold great promise for rapid and systematic identification and prioritization of CSEPs for functional characterization. In this review, we report on and discuss the current status of the poplar rust fungus secretome and prediction of candidate effectors from this species. PMID:26697026

  9. Water stress induces changes in polyphenol profile and antioxidant capacity in poplar plants (Populus spp.).

    PubMed

    Popović, B M; Štajner, D; Ždero-Pavlović, R; Tumbas-Šaponjac, V; Čanadanović-Brunet, J; Orlović, S

    2016-08-01

    This paper is aimed to characterize young poplar plants under the influence of water stress provoked by polyethileneglycol 6000 (PEG 6000). Three polar genotypes (M1, B229, and PE19/66) were grown in hydroponics and subjected to 100 and 200 mOsm PEG 6000 during six days. Polyphenol characterization, two enzymatic markers and antioxidant capacity in leaves and roots were investigated in stressed plants. Total phenol content, ferric reducing antioxidant capacity (FRAP) and DPPH antiradical power (DPPH ARP) were determined for estimating total antioxidant capacity. Polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were determined as enzymatic markers. Polyphenol characterization of poplar samples was performed by HPLC-PDA analysis. All results were subjected to correlation analysis and principal component analysis (PCA). Inspite of the decrease of total phenol content in investigated genotypes, as well as total antioxidant capacity, some of polyphenols were affected by stress like flavonoids chrysin, myricetine, kaempferol and isoferulic acid in roots of B229 genotype (Populus deltoides). Genotype B229 also showed the increase of antioxidant capacity and PAL activity in root and leaves under stress what could be the indicator of the adaptability of poplar plants to water stress. Significant positive correlations were obtained between PAL, antioxidant capacity as well as phenolic acids among themselves. Chemometric evaluation showed close interdependence between flavonoids, FRAP, DPPH antiradical power and both investigated enzymes of polyphenol metabolism, PAL and PPO. PMID:27116372

  10. A System for Dosage-Based Functional Genomics in Poplar[OPEN

    PubMed Central

    2015-01-01

    Altering gene dosage through variation in gene copy number is a powerful approach to addressing questions regarding gene regulation, quantitative trait loci, and heterosis, but one that is not easily applied to sexually transmitted species. Elite poplar (Populus spp) varieties are created through interspecific hybridization, followed by clonal propagation. Altered gene dosage relationships are believed to contribute to hybrid performance. Clonal propagation allows for replication and maintenance of meiotically unstable ploidy or structural variants and provides an alternative approach to investigating gene dosage effects not possible in sexually propagated species. Here, we built a genome-wide structural variation system for dosage-based functional genomics and breeding of poplar. We pollinated Populus deltoides with gamma-irradiated Populus nigra pollen to produce >500 F1 seedlings containing dosage lesions in the form of deletions and insertions of chromosomal segments (indel mutations). Using high-precision dosage analysis, we detected indel mutations in ∼55% of the progeny. These indels varied in length, position, and number per individual, cumulatively tiling >99% of the genome, with an average of 10 indels per gene. Combined with future phenotype and transcriptome data, this population will provide an excellent resource for creating and characterizing dosage-based variation in poplar, including the contribution of dosage to quantitative traits and heterosis. PMID:26320226

  11. Molecular cloning, expression analysis and subcellular localization of four DELLA genes from hybrid poplar.

    PubMed

    Liu, Sian; Xuan, Lei; Xu, Li-An; Huang, Minren; Xu, Meng

    2016-01-01

    Gibberellic acid (GA) signaling regulates diverse aspects of plant growth and developmental processes. The DELLA repressors of GA signaling are named for an N-terminal conserved DELLA domain. In this study, four genes encoding DELLA proteins, PeRGA1, PeRGA2, PeGAI1 and PeGAI2, were isolated and characterized in poplar. A gene structural analysis revealed that the DELLA genes were all intron-free. Multiple protein sequence alignments revealed that these proteins contained seven highly conserved domains: the DELLA domain, the TVHYNP domain, leucine heptad repeat I (LHR I), the VHIID domain, leucine heptad repeat II (LHR II), the PFYRE domain, and the SAM domain. Temporal expression patterns of these genes were profiled during the adventitious root development of poplar. The four DELLA genes were expressed in root, stem and leaf in a dynamic manner. The subcellular localization demonstrated that these DELLA genes were mainly localized to the nucleus. These results suggest that the four DELLA genes may play diverse regulatory roles in the adventitious root, stem and leaf development of poplar, and contribute to improving our understanding of conserved and divergent aspects of DELLA proteins that restrain GA signaling in various species. PMID:27478746

  12. Host Genotype Shapes the Foliar Fungal Microbiome of Balsam Poplar (Populus balsamifera)

    PubMed Central

    Bálint, Miklós; Tiffin, Peter; Hallström, Björn; O’Hara, Robert B.; Olson, Matthew S.; Fankhauser, Johnathon D.; Piepenbring, Meike; Schmitt, Imke

    2013-01-01

    Foliar fungal communities of plants are diverse and ubiquitous. In grasses endophytes may increase host fitness; in trees, their ecological roles are poorly understood. We investigated whether the genotype of the host tree influences community structure of foliar fungi. We sampled leaves from genotyped balsam poplars from across the species' range, and applied 454 amplicon sequencing to characterize foliar fungal communities. At the time of the sampling the poplars had been growing in a common garden for two years. We found diverse fungal communities associated with the poplar leaves. Linear discriminant analysis and generalized linear models showed that host genotypes had a structuring effect on the composition of foliar fungal communities. The observed patterns may be explained by a filtering mechanism which allows the trees to selectively recruit fungal strains from the environment. Alternatively, host genotype-specific fungal communities may be present in the tree systemically, and persist in the host even after two clonal reproductions. Both scenarios are consistent with host tree adaptation to specific foliar fungal communities and suggest that there is a functional basis for the strong biotic interaction. PMID:23326555

  13. Host genotype shapes the foliar fungal microbiome of balsam poplar (Populus balsamifera).

    PubMed

    Bálint, Miklós; Tiffin, Peter; Hallström, Björn; O'Hara, Robert B; Olson, Matthew S; Fankhauser, Johnathon D; Piepenbring, Meike; Schmitt, Imke

    2013-01-01

    Foliar fungal communities of plants are diverse and ubiquitous. In grasses endophytes may increase host fitness; in trees, their ecological roles are poorly understood. We investigated whether the genotype of the host tree influences community structure of foliar fungi. We sampled leaves from genotyped balsam poplars from across the species' range, and applied 454 amplicon sequencing to characterize foliar fungal communities. At the time of the sampling the poplars had been growing in a common garden for two years. We found diverse fungal communities associated with the poplar leaves. Linear discriminant analysis and generalized linear models showed that host genotypes had a structuring effect on the composition of foliar fungal communities. The observed patterns may be explained by a filtering mechanism which allows the trees to selectively recruit fungal strains from the environment. Alternatively, host genotype-specific fungal communities may be present in the tree systemically, and persist in the host even after two clonal reproductions. Both scenarios are consistent with host tree adaptation to specific foliar fungal communities and suggest that there is a functional basis for the strong biotic interaction.

  14. [Effect of flooding stress on transpiration of poplar I-69/55].

    PubMed

    Gao, J; Hou, C; Wu, Z

    2000-08-01

    The rates of transpiration(Tr) and photosynthesis(Pn) of poplar I-69/55 trees were measured under flooding stress. Flooding stress caused Pn and Tr decreasing, while in the period of measurement, Pn almost didn't change. The longer the period of flooding stress was, the more the Tr and stomatal conductance (Gs) decreased. Undre no stress, Pn and Tr of test trees displayed daily double-peak curves and seasonal variations, with the maximum in summer. Water use efficiency also displayed seasonal variation, with the maximum in autumn. Under no stress, Tr obviously changed with tree ages, with the order of 1 year-old > 3 year-old > 7 year-old. The rate of Tr/Pn in spring, summer and autumn was higher than that of other deciduous broad-leaved trees in the same region, especially in summer. The high Tr/Pn ratio means a high water consumption, which is beneficial to water loss of poplar I-69/55. In shoal sites, the temperature of leaf surface in summer and autumn is the most important factor that affects the transpiration rate of poplar I-69/55, suggesting that decreasing the temperature of leaf suface is beneficial to increase the transpiration rate. During the two days after flooding, the temperature of leaf surface is still the important factor that affects transpiration rate.

  15. Transport and fate of dieldrin in poplar and willow trees analyzed by SPME.

    PubMed

    Skaates, Serena V; Ramaswami, Anu; Anderson, Larry G

    2005-09-01

    Dieldrin is a hydrophobic organochlorine insecticide that is persistent in the environment. The fate and transport of dieldrin in trees is important both in the context of potential remediation, as well as food chain impacts through dieldrin transport to shoots and leaves. Experiments were conducted to measure the degree of dieldrin partitioning to plant tissue and the potential for biodegradation of dieldrin in the microbe rich tree rhizosphere. Dieldrin was analyzed in water and plant tissue using headspace solid-phase microextraction (SPME) coupled with gas chromatography. Poplar and willow saplings planted in soil and watered with 10 microgl(-1) dieldrin for up to 9 months showed no adverse effects due to dieldrin exposure and no dieldrin was observed in plant shoots with a method detection limit (MDL) of 7 ngg(-1). One-week hydroponic tests of poplar saplings exposed to aqueous dieldrin also showed no detection of dieldrin in shoots, with an average of 66% of the dieldrin partitioned to the plant roots and an overall mass balance recovery of 76% in the plant-water system. The root concentration factor (RCF) was found to be 30+/-3 ml water g(-1) root. Biodegradation of dieldrin was not observed in an aqueous batch bioreactor containing 8 microgl(-1) dieldrin, nutrients and bacteria from the root zone of a poplar sapling that had been exposed to dieldrin for 9 months. These results show that planting trees is likely to be safe and potentially useful at sites containing low-levels of dieldrin in groundwater.

  16. Boron accumulation and toxicity in hybrid poplar (Populus nigra × euramericana).

    PubMed

    Rees, Rainer; Robinson, Brett H; Menon, Manoj; Lehmann, Eberhard; Günthardt-Goerg, Madeleine S; Schulin, Rainer

    2011-12-15

    Poplars accumulate high B concentrations and are thus used for the phytomanagement of B contaminated soils. Here, we performed pot experiments in which Populus nigra × euramericana were grown on a substrate with B concentrations ranging from 13 to 280 mg kg(-1) as H(3)BO(3). Salix viminalis, Brassica juncea, and Lupinus albus were grown under some growing conditions for comparison. Poplar growth was unaffected at soil B treatment levels up to 93 mg kg(-1). Growth was progressively reduced at levels of 168 and 280 mg kg(-1). None of the other species survived at these substrate B levels. At leaf B concentrations <900 mg kg(-1) only <10% of the poplar leaf area showed signs of toxicity. Neutron radiography revealed that chlorotic leaf tissues had B concentrations of 1000-2000 mg kg(-1), while necrotic tissues had >2000 mg kg(-1). Average B concentrations of up to 3500 mg kg(-1) were found in leaves, while spots within leaves had concentrations >7000 mg kg(-1), showing that B accumulation in leaf tissue continued even after the onset of necrosis. The B accumulation ability of P. nigra × euramericana is associated with B hypertolerance in the living tissue and storage of B in dead leaf tissue.

  17. Water consumption and biomass production of protoplast fusion lines of poplar hybrids under drought stress

    PubMed Central

    Hennig, Anne; Kleinschmit, Jörg R. G.; Schoneberg, Sebastian; Löffler, Sonja; Janßen, Alwin; Polle, Andrea

    2015-01-01

    Woody crops such as poplars (Populus) can contribute to meet the increasing energy demand of a growing human population and can therefore enhance the security of energy supply. Using energy from biomass increases ecological sustainability as biomass is considered to play a pivotal role in abating climate change. Because areas for establishing poplar plantations are often confined to marginal sites drought tolerance is one important trait for poplar genotypes cultivated in short rotation coppice. We tested 9-month-old plants of four tetraploid Populus tremula (L.) × P. tremuloides (Michx.) lines that were generated by protoplast fusion and their diploid counterpart for water consumption and drought stress responses in a greenhouse experiment. The fusion lines showed equivalent or decreased height growth, stem biomass and total leaf area compared to the diploid line. The relative height increment of the fusion lines was not reduced compared to the diploid line when the plants were exposed to drought. The fusion lines were distinguished from the diploid counterpart by stomatal characteristics such as increased size and lower density. The changes in the stomatal apparatus did not affect the stomatal conductance. When exposed to drought the carbohydrate concentrations increased more strongly in the fusion lines than in the diploid line. Two fusion lines consumed significantly less water with regard to height growth, producing equivalent or increased relative stem biomass under drought compared to their diploid relative. Therefore, these tetraploid fusion lines are interesting candidates for short rotation biomass plantation on dry sites. PMID:26042130

  18. Transgenic Spartina alterniflora for phytoremediation.

    PubMed

    Czakó, Mihály; Feng, Xianzhong; He, Yuke; Liang, Dali; Márton, László

    2006-01-01

    Perennial monoculture forming grasses are very important natural remediators of pollutants. Their genetic improvement is an important task because introduction of key transgenes can dramatically improve their remediation potential. Transfer of key genes for mercury phytoremediation into the salt marsh cordgrass (Spartina alterniflora) is reported here. S. alterniflora plays an important role in the salt marsh by cycling of elements, both nutrients and pollutants, protects the coastline from erosion, is a keystone species in the salt marsh supporting a large food web, which in turn supports a significant segment of economy, including tourism, has an impact on cloud formation and consequently on global weather, and is thus an ecologically important species relevant for our life-support systems. Embryogenic callus of S. alterniflora was co-inoculated with a pair of Agrobacterium strains LBA4404 carrying the organomercurial lyase (merB) and mercuric reductase (merA) genes, respectively, in order to co-introduce both the merA and the merB genes. Seven stable geneticin resistant lines were recovered. The presence of merA and merB genes was verified by PCR and Southern blotting. All but one transgenic lines contained both the merA and the merB sequences proving that co-introduction into Spartina of two genes from separate Agrobacterium strains is feasible and frequent, although the overall frequency of transformation is low. Northern blotting showed differences in relative expression of the two transgenes among individual transformants. The steady-state RNA levels appeared to correlate with the phenotype. Line #7 showed the highest resistance to HgCl(2) (up to 500 microM), whereas line #3 was the most resistant to phenylmercuric acetate (PMA). Wild-type (WT) callus is sensitive to PMA at 50 microM and to HgCl(2) at 225 microM.

  19. Transgenic Models in Retinoblastoma Research.

    PubMed

    Nair, Rohini M; Vemuganti, Geeta K

    2015-04-01

    Understanding the mechanism of retinoblastoma (Rb) tumor initiation, development, progression and metastasis in vivo mandates the use of animal models that mimic this intraocular tumor in its genetic, anatomic, histologic and ultrastructural features. An early setback for developing mouse Rb models was that Rb mutations did not cause tumorigenesis in murine retinas. Subsequently, the discovery that the p107 protein takes over the role of pRb in mice led to the development of several animal models that phenotypically and histologically resemble the human form. This paper summarizes the transgenic models that have been developed over the last three decades. PMID:27171579

  20. Production of transgenic livestock: promise fulfilled.

    PubMed

    Wheeler, M B

    2003-01-01

    The introduction of specific genes into the genome of farm animals and its stable incorporation into the germ line has been a major technological advance in agriculture. Transgenic technology provides a method to rapidly introduce "new" genes into cattle, swine, sheep, and goats without crossbreeding. It is a more extreme methodology, but in essence, not really different from crossbreeding or genetic selection in its result. Methods to produce transgenic animals have been available for more than 20 yr, yet recently lines of transgenic livestock have been developed that have the potential to improve animal agriculture and benefit producers and/or consumers. There are a number of methods that can be used to produce transgenic animals. However, the primary method to date has been the microinjection of genes into the pronuclei of zygotes. This method is one of an array of rapidly developing transgenic methodologies. Another method that has enjoyed recent success is that of nuclear transfer or "cloning." The use of this technique to produce transgenic livestock will profoundly affect the use of transgenic technology in livestock production. Cell-based, nuclear transfer or cloning strategies have several distinct advantages for use in the production of transgenic livestock that cannot be attained using pronuclear injection of DNA. Practical applications of transgenesis in livestock production include enhanced prolificacy and reproductive performance, increased feed utilization and growth rate, improved carcass composition, improved milk production and/or composition, and increased disease resistance. One practical application of transgenics in swine production is to improve milk production and/or composition. To address the problem of low milk production, transgenic swine over-expressing the milk protein bovine alpha-lactalbumin were developed and characterized. The outcomes assessed were milk composition, milk yield, and piglet growth. Our results indicate that

  1. Genetic Modification of Short Rotation Poplar Biomass Feedstock for Efficient Conversion to Ethanol

    SciTech Connect

    Dinus, R.J.

    2000-08-30

    The Bioenergy Feedstock Development Program, Environmental Sciences Division, Oak Ridge National Laboratory is developing poplars (Populus species and hybrids) as sources of renewable energy, i.e., ethanol. Notable increases in adaptability, volume productivity, and pest/stress resistance have been achieved via classical selection and breeding and intensified cultural practices. Significant advances have also been made in the efficiencies of harvesting and handling systems. Given these and anticipated accomplishments, program leaders are considering shifting some attention to genetically modifying feedstock physical and chemical properties, so as to improve the efficiency with which feedstocks can be converted to ethanol. This report provides an in-depth review and synthesis of opportunities for and feasibilities of genetically modifying feedstock qualities via classical selection and breeding, marker-aided selection and breeding, and genetic transformation. Information was collected by analysis of the literature, with emphasis on that published since 1995, and interviews with prominent scientists, breeders, and growers. Poplar research is well advanced, and literature is abundant. The report therefore primarily reflects advances in poplars, but data from other species, particularly other shortrotation hardwoods, are incorporated to fill gaps. An executive summary and recommendations for research, development, and technology transfer are provided immediately after the table of contents. The first major section of the report describes processes most likely to be used for conversion of poplar biomass to ethanol, the various physical and chemical properties of poplar feedstocks, and how such properties are expected to affect process efficiency. The need is stressed for improved understanding of the impact of change on both overall process and individual process step efficiencies. The second part documents advances in trait measurement instrumentation and methodology

  2. GHGs balance in a land use change process from grassland to short rotation coppice of poplar

    NASA Astrophysics Data System (ADS)

    Sabbatini, Simone; Arriga, Nicola; Baiocco, Andrea; Boschi, Alessio; Castaldi, Simona; Consalvo, Claudia; Gioli, Beniamino; Matteucci, Giorgio; Tomassucci, Michele; Zaldei, Alessandro; Papale, Dario

    2013-04-01

    At present one of the fastest spreading renewable energy sources are bioenergy cultivations. Millions of hectares of traditional crops all over the Europe are expected to be converted in energy crops in the near future, in order to produce green energy and contrast global warming. Last year, in the context of the GHG-Europe FP7 project we set up an experiment to verify the effects on the green-house gases balance of a land use change from traditional agriculture to short rotation coppice of poplar clones in central Italy. CO2 fluxes measured during the last growing season through three Eddy Covariance masts - two on poplar plantations of different ages and one over a reference site (grassland) - have been analysed. We also monitored CO2, CH4 and N2O fluxes from soil measured using chambers in order to better understand the contribution of other GHGs. The two poplar plantations showed a similar uptake of Carbon, 368 g C m-2 year-1 and 358 g C m-2 year-1, while the grassland absorbed 220 g C m-2 year-1 during the same period. Soil respiration in average was higher for the youngest plantation of poplar and for the grassland, lower for the oldest one, where soil is undisturbed from more time. In all the sites we measured low emissions during the winter (between 80 and 150 mg CO2 m-2 h-1), progressively higher in the spring and early summer with growing temperatures (up to 650 mg CO2 m-2 h-1), quite low during the summer because of a strong drought, while the highest values were recorded in September (ca. 1100 mg CO2 m-2 h-1 in the grassland and youngest poplar) after important rain events. Fluxes of N2O and CH4 from soil are very low: little absorption of CH4 in the grassland (values between 0 and -18.75 μg m-2 h-1), with peak after fertilization; in the SRC little absorption or emission with no clear seasonal pattern. Insignificant fluxes of N2O in all crops (even in the grassland after fertilization). The carbon fluxes measured are strongly related to the particular

  3. Transgenic animals: current and alternative strategies.

    PubMed

    Chan, A W

    1999-01-01

    Transgenic animal technology is one of the most fascinating technologies developed in the last two decades. It allows us to address questions in life sciences that no other methods have achieved. The impact on biomedical and biological research, as well as commercial interests are overwhelming. The questions accompanying this fast growing technology and its diversified applications attract the attention from a variety of entities. Still, one of the most fundamental problems remaining is the search for an efficient and reliable gene delivery system for creating transgenic animals. The traditional method of pronuclear microinjection has displayed great variability in success among species. While an acceptable efficiency in the production of transgenic mice has been attained, the relative low efficiency (<1%) in creating transgenic livestock has become one of the barriers for its application. In the past decades, improvements in producing transgenic livestock have made a slow progression, however, the recent advancement in cloning technology and the ability to create transgenic livestock in a highly efficient manner, have opened the gate to a new era in transgenic technology. Discoveries of new gene delivery systems have created an enthusiastic atmosphere that has made this technology so unique. This review focuses on gene delivery strategies as well as various approaches that may assist the advancement of transgenic efficiency in large animals.

  4. [New advances in animal transgenic technology].

    PubMed

    Sun, Zhen-Hong; Miao, Xiang-Yang; Zhu, Rui-Liang

    2010-06-01

    Animal transgenic technology is one of the fastest growing biotechnology in the 21st century. It is used to integrate foreign genes into the animal genome by genetic engineering technology so that foreign genes can be expressed and inherited to the offspring. The transgenic efficiency and precise control of gene expression are the key limiting factors on preparation of transgenic animals. A variety of transgenic techniques are available, each of which has its own advantages and disadvantages and still needs further study because of unresolved technical and safety issues. With the in-depth research, the transgenic technology will have broad application prospects in the fields of exploration of gene function, animal genetic improvement, bioreactor, animal disease models, organ transplantation and so on. This article reviews the recently developed animal gene transfer techniques, including germline stem cell mediated method to improve the efficiency, gene targeting to improve the accuracy, RNA interference (RNAi)-mediated gene silencing technology, and the induced pluripotent stem cells (iPS) transgenic technology. The new transgenic techniques can provide a better platform for the study of trans-genic animals and promote the development of medical sciences, livestock production, and other fields.

  5. [Progress in transgenic fish techniques and application].

    PubMed

    Ye, Xing; Tian, Yuan-Yuan; Gao, Feng-Ying

    2011-05-01

    Transgenic technique provides a new way for fish breeding. Stable lines of growth hormone gene transfer carps, salmon and tilapia, as well as fluorescence protein gene transfer zebra fish and white cloud mountain minnow have been produced. The fast growth characteristic of GH gene transgenic fish will be of great importance to promote aquaculture production and economic efficiency. This paper summarized the progress in transgenic fish research and ecological assessments. Microinjection is still the most common used method, but often resulted in multi-site and multi-copies integration. Co-injection of transposon or meganuclease will greatly improve the efficiency of gene transfer and integration. "All fish" gene or "auto gene" should be considered to produce transgenic fish in order to eliminate misgiving on food safety and to benefit expression of the transferred gene. Environmental risk is the biggest obstacle for transgenic fish to be commercially applied. Data indicates that transgenic fish have inferior fitness compared with the traditional domestic fish. However, be-cause of the genotype-by-environment effects, it is difficult to extrapolate simple phenotypes to the complex ecological interactions that occur in nature based on the ecological consequences of the transgenic fish determined in the laboratory. It is critical to establish highly naturalized environments for acquiring reliable data that can be used to evaluate the environ-mental risk. Efficacious physical and biological containment strategies remain to be crucial approaches to ensure the safe application of transgenic fish technology.

  6. Overexpression of Two PsnAP1 Genes from Populus simonii × P. nigra Causes Early Flowering in Transgenic Tobacco and Arabidopsis

    PubMed Central

    Zheng, Tangchun; Li, Shuang; Zang, Lina; Dai, Lijuan; Yang, Chuanping; Qu, Guan-Zheng

    2014-01-01

    In Arabidopsis, AP1 is a floral meristem identity gene and plays an important role in floral organ development. In this study, PsnAP1-1 and PsnAP1-2 were isolated from the male reproductive buds of poplar (Populus simonii × P. nigra), which are the orthologs of AP1 in Arabidopsis, by sequence analysis. Northern blot and qRT-PCR analysis showed that PsnAP1-1 and PsnAP1-2 exhibited high expression level in early inflorescence development of poplar. Subcellular localization showed the PsnAP1-1 and PsnAP1-2 proteins are localized in the nucleus. Overexpression of PsnAP1-1 and PsnAP1-2 in tobacco under the control of a CaMV 35S promoter significantly enhanced early flowering. These transgenic plants also showed much earlier stem initiation and higher rates of photosynthesis than did wild-type tobacco. qRT-PCR analysis further indicated that overexpression of PsnAP1-1 and PsnAP1-2 resulted in up-regulation of genes related to flowering, such as NtMADS4, NtMADS5 and NtMADS11. Overexpression of PsnAP1-1 and PsnAP1-2 in Arabidopsis also induced early flowering, but did not complement the ap1-10 floral morphology to any noticeable extent. This study indicates that PsnAP1-1 and PsnAP1-2 play a role in floral transition of poplar. PMID:25360739

  7. Conversion from cropland to short rotation coppice willow and poplar: Accumulation of soil organic carbon

    NASA Astrophysics Data System (ADS)

    Georgiadis, Petros; Stupak, Inge; Vesterdal, Lars; Raulund-Rasmussen, Karsten

    2015-04-01

    Increased demand for bioenergy has intensified the production of Short Rotation Coppice (SRC) willow and poplar in temperate zones. We used a combined chronosequence and paired plot approach to study the potential of SRC willow and poplar stands to increase the soil carbon stock compared to stocks of the previous arable land-use. The study focused on well-drained soils. We sampled soil from 30 SRC stands in Denmark and southern Sweden including soils from their adjacent arable fields. The 18 willow and 12 poplar stands formed a chronosequence ranging between 4 and 29 years after conversion. The soil was sampled both with soil cores taken by fixed depths of 0-5, 5-10, 10-15, 15-25, and 25-40 cm and by genetic horizons from soil pits to 1m depth. The aim of the study was to estimate the difference and the ratio between soil carbon contents of the SRC and annual crop land and analyze the results as a chronosequence to examine the effect of age after conversion on the difference. Covariates such as soil type, fertilization type and harvest frequency were also taken into account. Preliminary results suggest an overall increase in carbon stocks over time with average accumulation rates ranging from 0.25 to 0.4 Mg ha-1 yr-1 in willow and poplar stands. Poplar stands had higher rates of C gain, probably due to less frequent harvesting. The differences in carbon between the SRC and the paired cropland were initially negative but changed to positive over time, implying loss of carbon after conversion and a later gain in soil carbon with stand age. Pairwise differences ranged from -25 Mg C ha-1 to 37 Mg C ha-1 for the top 40 cm. The carbon stock ratio of the SRC stand to the arable land was estimated to minimize the effect of site-related factors. The results of this analysis suggested that the ratio increased significantly with age after conversion for the top 10 cm of the soil, both for poplar and willow. A slight increase with age was also noticed at the deeper depths, but

  8. Accumulation of nickel in transgenic tobacco

    NASA Astrophysics Data System (ADS)

    Sidik, Nik Marzuki; Othman, Noor Farhan

    2013-11-01

    The accumulation of heavy metal Ni in the roots and leaves of four T1 transgenic lines of tobacco (T(1)20E, T(1)24C, T(1)18B1 and T(1)20B) expressing eiMT1 from E.indica was assessed. The aim of the study was to investigate the level of Ni accumulation in the leaves and roots of each transgenic lines and to evaluate the eligibility of the plants to be classified as a phytoremediation agent. All of the transgenic lines showed different ability in accumulating different metals and has translocation factor (TF) less than 1 (TF<1) at all levels of metal treatment. Among the 4 transgenic lines, transgenic line T(1)24C showed the highest accumulation of Ni (251.9 ± 0.014 mg/kg) and the lowest TF value (TFT(1)24C=0.0875) at 60 ppm Ni.

  9. [Time lag effect between poplar' s sap flow velocity and microclimate factors in agroforestry system in West Liaoning Province].

    PubMed

    Di, Sun; Guan, De-xin; Yuan, Feng-hui; Wang, An-zhi; Wu, Jia-bing

    2010-11-01

    By using Granier's thermal dissipation probe, the sap flow velocity of the poplars in agroforestry system in west Liaoning was continuously measured, and the microclimate factors were measured synchronously. Dislocation contrast method was applied to analyze the sap flow velocity and corresponding air temperature, air humidity, net radiation, and vapor pressure deficit to discuss the time lag effect between poplar' s sap flow velocity and microclimate factors on sunny days. It was found that the poplar's sap flow velocity advanced of air temperature, air humidity, and vapor pressure deficit, and lagged behind net radiation. The sap flow velocity in June, July, August, and September was advanced of 70, 30, 50, and 90 min to air temperature, of 80, 30, 40, and 90 min to air humidity, and of 90, 50, 70, and 120 min to vapor pressure deficit, but lagged behind 10, 10, 40, and 40 min to net radiation, respectively. The time lag time of net radiation was shorter than that of air temperature, air humidity, and vapor pressure. The regression analysis showed that in the cases the time lag effect was contained and not, the determination coefficients between comprehensive microclimate factor and poplar's sap flow velocity were 0.903 and 0.855, respectively, indicating that when the time lag effect was contained, the determination coefficient was ascended by 2.04%, and thus, the simulation accuracy of poplar's sap flow velocity was improved. PMID:21360994

  10. [Time lag effect between poplar' s sap flow velocity and microclimate factors in agroforestry system in West Liaoning Province].

    PubMed

    Di, Sun; Guan, De-xin; Yuan, Feng-hui; Wang, An-zhi; Wu, Jia-bing

    2010-11-01

    By using Granier's thermal dissipation probe, the sap flow velocity of the poplars in agroforestry system in west Liaoning was continuously measured, and the microclimate factors were measured synchronously. Dislocation contrast method was applied to analyze the sap flow velocity and corresponding air temperature, air humidity, net radiation, and vapor pressure deficit to discuss the time lag effect between poplar' s sap flow velocity and microclimate factors on sunny days. It was found that the poplar's sap flow velocity advanced of air temperature, air humidity, and vapor pressure deficit, and lagged behind net radiation. The sap flow velocity in June, July, August, and September was advanced of 70, 30, 50, and 90 min to air temperature, of 80, 30, 40, and 90 min to air humidity, and of 90, 50, 70, and 120 min to vapor pressure deficit, but lagged behind 10, 10, 40, and 40 min to net radiation, respectively. The time lag time of net radiation was shorter than that of air temperature, air humidity, and vapor pressure. The regression analysis showed that in the cases the time lag effect was contained and not, the determination coefficients between comprehensive microclimate factor and poplar's sap flow velocity were 0.903 and 0.855, respectively, indicating that when the time lag effect was contained, the determination coefficient was ascended by 2.04%, and thus, the simulation accuracy of poplar's sap flow velocity was improved.

  11. Genome survey and characterization of endophytic bacteria exhibiting a beneficial effect on growth and development of poplar trees.

    PubMed

    Taghavi, Safiyh; Garafola, Craig; Monchy, Sébastien; Newman, Lee; Hoffman, Adam; Weyens, Nele; Barac, Tanja; Vangronsveld, Jaco; van der Lelie, Daniel

    2009-02-01

    The association of endophytic bacteria with their plant hosts has a beneficial effect for many different plant species. Our goal is to identify endophytic bacteria that improve the biomass production and the carbon sequestration potential of poplar trees (Populus spp.) when grown in marginal soil and to gain an insight in the mechanisms underlying plant growth promotion. Members of the Gammaproteobacteria dominated a collection of 78 bacterial endophytes isolated from poplar and willow trees. As representatives for the dominant genera of endophytic gammaproteobacteria, we selected Enterobacter sp. strain 638, Stenotrophomonas maltophilia R551-3, Pseudomonas putida W619, and Serratia proteamaculans 568 for genome sequencing and analysis of their plant growth-promoting effects, including root development. Derivatives of these endophytes, labeled with gfp, were also used to study the colonization of their poplar hosts. In greenhouse studies, poplar cuttings (Populus deltoides x Populus nigra DN-34) inoculated with Enterobacter sp. strain 638 repeatedly showed the highest increase in biomass production compared to cuttings of noninoculated control plants. Sequence data combined with the analysis of their metabolic properties resulted in the identification of many putative mechanisms, including carbon source utilization, that help these endophytes to thrive within a plant environment and to potentially affect the growth and development of their plant hosts. Understanding the interactions between endophytic bacteria and their host plants should ultimately result in the design of strategies for improved poplar biomass production on marginal soils as a feedstock for biofuels.

  12. Collapse of riparian poplar forests downstream from dams in western prairies: Probable causes and prospects for mitigation

    NASA Astrophysics Data System (ADS)

    Rood, Stewart B.; Mahoney, John M.

    1990-07-01

    Although historically abundant, the riparian poplar forests of the western prairies are now endangered as a result of the damming and diversion of rivers in this region. Recent reports have described substantial declines of riparian poplar forests downstream from dams in Alberta, Canada; Montana, North Dakota, Wyoming, Colorado, and Arizona, USA. The present report analyzes the forest and hydrological conditions reported previously in order to clarify the causes of the downstream forest decline. Dams were found to contribute to forest failure by (1) reducing downstream flows and/or (2) altering flow patterns to attenuate spring flooding and/or stabilize summer flows. Reduced flows are reported to induce drought stress, which is particularly lethal to seedlings and very old poplars. The artificial moderation of spring flooding may inhibit the formation of seedbeds essential for seedling replenishment. Increased river valley development involving cattle grazing, agricultural clearing, and direct harvesting of trees also contributes to forest failure. Potential methods for mitigating the impacts of dams on downstream forests include downstream flow schedules that (1) retain occasional spring flooding, (2) taper off rather than abruptly drop downstream flow, and (3) provide adequate flows throughout the summer. Poplar forest stabilization and recovery can be further promoted by fencing to protect trees from livestock grazing and trampling, or artificial site preparation such as cultivation or scarification to encourage poplar regeneration.

  13. Genome Survey and Characterization of Endophytic Bacteria Exhibiting a Beneficial Effect on Growth and Development of Poplar Trees ▿ †

    PubMed Central

    Taghavi, Safiyh; Garafola, Craig; Monchy, Sébastien; Newman, Lee; Hoffman, Adam; Weyens, Nele; Barac, Tanja; Vangronsveld, Jaco; van der Lelie, Daniel

    2009-01-01

    The association of endophytic bacteria with their plant hosts has a beneficial effect for many different plant species. Our goal is to identify endophytic bacteria that improve the biomass production and the carbon sequestration potential of poplar trees (Populus spp.) when grown in marginal soil and to gain an insight in the mechanisms underlying plant growth promotion. Members of the Gammaproteobacteria dominated a collection of 78 bacterial endophytes isolated from poplar and willow trees. As representatives for the dominant genera of endophytic gammaproteobacteria, we selected Enterobacter sp. strain 638, Stenotrophomonas maltophilia R551-3, Pseudomonas putida W619, and Serratia proteamaculans 568 for genome sequencing and analysis of their plant growth-promoting effects, including root development. Derivatives of these endophytes, labeled with gfp, were also used to study the colonization of their poplar hosts. In greenhouse studies, poplar cuttings (Populus deltoides × Populus nigra DN-34) inoculated with Enterobacter sp. strain 638 repeatedly showed the highest increase in biomass production compared to cuttings of noninoculated control plants. Sequence data combined with the analysis of their metabolic properties resulted in the identification of many putative mechanisms, including carbon source utilization, that help these endophytes to thrive within a plant environment and to potentially affect the growth and development of their plant hosts. Understanding the interactions between endophytic bacteria and their host plants should ultimately result in the design of strategies for improved poplar biomass production on marginal soils as a feedstock for biofuels. PMID:19060168

  14. Rapid characterization of transgenic and non-transgenic soybean oils by chemometric methods using NIR spectroscopy.

    PubMed

    Luna, Aderval S; da Silva, Arnaldo P; Pinho, Jéssica S A; Ferré, Joan; Boqué, Ricard

    2013-01-01

    Near infrared (NIR) spectroscopy and multivariate classification were applied to discriminate soybean oil samples into non-transgenic and transgenic. Principal Component Analysis (PCA) was applied to extract relevant features from the spectral data and to remove the anomalous samples. The best results were obtained when with Support Vectors Machine-Discriminant Analysis (SVM-DA) and Partial Least Squares-Discriminant Analysis (PLS-DA) after mean centering plus multiplicative scatter correction. For SVM-DA the percentage of successful classification was 100% for the training group and 100% and 90% in validation group for non transgenic and transgenic soybean oil samples respectively. For PLS-DA the percentage of successful classification was 95% and 100% in training group for non transgenic and transgenic soybean oil samples respectively and 100% and 80% in validation group for non transgenic and transgenic respectively. The results demonstrate that NIR spectroscopy can provide a rapid, nondestructive and reliable method to distinguish non-transgenic and transgenic soybean oils.

  15. Rapid characterization of transgenic and non-transgenic soybean oils by chemometric methods using NIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Luna, Aderval S.; da Silva, Arnaldo P.; Pinho, Jéssica S. A.; Ferré, Joan; Boqué, Ricard

    Near infrared (NIR) spectroscopy and multivariate classification were applied to discriminate soybean oil samples into non-transgenic and transgenic. Principal Component Analysis (PCA) was applied to extract relevant features from the spectral data and to remove the anomalous samples. The best results were obtained when with Support Vectors Machine-Discriminant Analysis (SVM-DA) and Partial Least Squares-Discriminant Analysis (PLS-DA) after mean centering plus multiplicative scatter correction. For SVM-DA the percentage of successful classification was 100% for the training group and 100% and 90% in validation group for non transgenic and transgenic soybean oil samples respectively. For PLS-DA the percentage of successful classification was 95% and 100% in training group for non transgenic and transgenic soybean oil samples respectively and 100% and 80% in validation group for non transgenic and transgenic respectively. The results demonstrate that NIR spectroscopy can provide a rapid, nondestructive and reliable method to distinguish non-transgenic and transgenic soybean oils.

  16. QTLs for Woolly Poplar Aphid (Phloeomyzus passerinii L.) Resistance Detected in an Inter-Specific Populus deltoides x P. nigra Mapping Population

    PubMed Central

    Carletti, Giorgia; Carra, Andrea; Allegro, Gianni; Vietto, Lorenzo; Desiderio, Francesca; Bagnaresi, Paolo; Gianinetti, Alberto; Cattivelli, Luigi; Valè, Giampiero; Nervo, Giuseppe

    2016-01-01

    The genus Populus represents one of the most economically important groups of forest trees. It is composed by approximately 30 species used for wood and non-wood products, phytoremediation and biomass. Poplar is subjected to several biological and environmental threats although, compared to annual crops, we know far less about the genetic bases of biotic stress resistance. Woolly poplar aphid (Phloeomyzus passerinii) is considered a main pest of cultivated poplars in European and American countries. In this work we present two high density linkage maps in poplar obtained by a genotyping by sequencing (GBS) approach and the identification of QTLs involved in Ph. passerinii resistance. A total of 5,667 polymorphic markers (5,606 SNPs and 61 SSRs) identified on expressed sequences have been used to genotype 131 plants of an F1 population P ×canadensis obtained by an interspecific mate between Populus deltoides (resistant to woolly poplar aphid) and Populus nigra (susceptible to woolly poplar aphid). The two linkage maps, obtained following the two-way pseudo-testcross mapping strategy, have been used to investigate the genetic bases of woolly poplar aphid resistance. One major QTL and two QTLs with minor effects (mapped on LGV, LGXVI and LG XIX) explaining the 65.8% of the genetic variance observed in the progeny in response to Ph. passerinii attack were found. The high density coverage of functional markers allowed the identification of three genes belonging to disease resistance pathway as putative candidates for P. deltoides resistance to woolly poplar aphid. This work is the first report on genetic of woolly poplar aphid genetic resistance and the resistant loci associated markers identified represent a valuable tool in resistance poplar breeding programs. PMID:27022954

  17. Synergistic benefits of ionic liquid and alkaline pretreatments of poplar wood. Part 1: effect of integrated pretreatment on enzymatic hydrolysis.

    PubMed

    Yuan, Tong-Qi; Wang, Wei; Xu, Feng; Sun, Run-Cang

    2013-09-01

    An environmentally friendly pretreatment process was developed to fractionate hemicelluloses and lignin from poplar wood by ionic liquid (IL) pretreatment coupled with mild alkaline extraction. Hemicellulosic and lignin fractions were obtained in high yields, amounting to 59.3% and 74.4%, respectively, which can served as raw materials for production of value-added products. The yield of glucose for the integrated pretreated poplar wood was 99.2%, while it was just 19.2% for the untreated material. The synergistic benefits of the removal of lignin and hemicelluloses, the increase of the cellulose surface area, and the conversion of cellulose fibers from the cellulose I to the cellulose II crystal phase resulted in the high glucose yield for the integrated pretreated substrate. Therefore, the IL based biorefining strategy proposed can integrate biofuels production into a biorefinery scheme in which the major components of poplar wood can be converted into value-added products.

  18. Enhanced enzymatic hydrolysis of poplar bark by combined use of gamma ray and dilute acid for bioethanol production

    NASA Astrophysics Data System (ADS)

    Chung, Byung Yeoup; Lee, Jae Taek; Bai, Hyoung-Woo; Kim, Ung-Jin; Bae, Hyeun-Jong; Gon Wi, Seung; Cho, Jae-Young

    2012-08-01

    Pretreatment of poplar bark with a combination of sulfuric acid (3%, w/w, H2SO4) and gamma irradiation (0-1000 kGy) was performed in an attempt to enhance enzymatic hydrolysis for bioethanol production. The yields of reducing sugar were slightly increased with an increasing irradiation dose, ranging from 35.4% to 51.5%, with a 56.1% reducing sugar yield observed after dilute acid pretreatment. These results clearly showed that soluble sugars were released faster and to a greater extent in dilute acid-pretreated poplar bark than in gamma irradiation-pretreated bark. When combined pretreatment was carried out, a drastic increase in reducing sugar yield (83.1%) was found compared with individual pretreatment, indicating the possibility of increasing the convertibility of poplar bark following combined pretreatment. These findings are likely associated with cellulose crystallinity, lignin modification, and removal of hemicelluloses.

  19. Generation of transgenic Hydra by embryo microinjection.

    PubMed

    Juliano, Celina E; Lin, Haifan; Steele, Robert E

    2014-09-11

    As a member of the phylum Cnidaria, the sister group to all bilaterians, Hydra can shed light on fundamental biological processes shared among multicellular animals. Hydra is used as a model for the study of regeneration, pattern formation, and stem cells. However, research efforts have been hampered by lack of a reliable method for gene perturbations to study molecular function. The development of transgenic methods has revitalized the study of Hydra biology(1). Transgenic Hydra allow for the tracking of live cells, sorting to yield pure cell populations for biochemical analysis, manipulation of gene function by knockdown and over-expression, and analysis of promoter function. Plasmid DNA injected into early stage embryos randomly integrates into the genome early in development. This results in hatchlings that express transgenes in patches of tissue in one or more of the three lineages (ectodermal epithelial, endodermal epithelial, or interstitial). The success rate of obtaining a hatchling with transgenic tissue is between 10% and 20%. Asexual propagation of the transgenic hatchling is used to establish a uniformly transgenic line in a particular lineage. Generating transgenic Hydra is surprisingly simple and robust, and here we describe a protocol that can be easily implemented at low cost.

  20. Generation of Transgenic Hydra by Embryo Microinjection

    PubMed Central

    Juliano, Celina E.; Lin, Haifan; Steele, Robert E.

    2014-01-01

    As a member of the phylum Cnidaria, the sister group to all bilaterians, Hydra can shed light on fundamental biological processes shared among multicellular animals. Hydra is used as a model for the study of regeneration, pattern formation, and stem cells. However, research efforts have been hampered by lack of a reliable method for gene perturbations to study molecular function. The development of transgenic methods has revitalized the study of Hydra biology1. Transgenic Hydra allow for the tracking of live cells, sorting to yield pure cell populations for biochemical analysis, manipulation of gene function by knockdown and over-expression, and analysis of promoter function. Plasmid DNA injected into early stage embryos randomly integrates into the genome early in development. This results in hatchlings that express transgenes in patches of tissue in one or more of the three lineages (ectodermal epithelial, endodermal epithelial, or interstitial). The success rate of obtaining a hatchling with transgenic tissue is between 10% and 20%. Asexual propagation of the transgenic hatchling is used to establish a uniformly transgenic line in a particular lineage. Generating transgenic Hydra is surprisingly simple and robust, and here we describe a protocol that can be easily implemented at low cost. PMID:25285460

  1. Glyphostate-drift but not herbivory alters the rate of transgene flow from single and stacked trait transgenic canola (Brassica napus L.) to non-transgenic B. napus and B. rapa

    EPA Science Inventory

    While transgenic plants can offer agricultural benefits, the escape of transgenes out of crop fields is a major environmental concern. Escape of transgenic herbicide resistance has occurred between transgenic Brassica napus (canola) and weedy species in numerous locations. In t...

  2. [Transgenic technology and soybean quality improvement].

    PubMed

    Cheng, Hao; Jin, Hang-Xia; Gai, Jun-Yi; Yu, De-Yue

    2011-05-01

    Soybean is an important source of edible oil, protein and protein diet. The breeding process of high quality soybean can be accelerated via employment of transgenic technology, by which the key genes for soybean quality traits could be directly manipulated. Thus, various soybean varieties could be bred to fulfill different needs for specific consumers. Here, we reviewed the contribution of transgenic technology to improvement of soybean qualities in recent years. We also introduce some newly developed safe transgenic technologies and hope this information could relieve some concerns on the GM food.

  3. Expression of multiple proteins in transgenic plants

    DOEpatents

    Vierstra, Richard D.; Walker, Joseph M.

    2002-01-01

    A method is disclosed for the production of multiple proteins in transgenic plants. A DNA construct for introduction into plants includes a provision to express a fusion protein of two proteins of interest joined by a linking domain including plant ubiquitin. When the fusion protein is produced in the cells of a transgenic plant transformed with the DNA construction, native enzymes present in plant cells cleave the fusion protein to release both proteins of interest into the cells of the transgenic plant. Since the proteins are produced from the same fusion protein, the initial quantities of the proteins in the cells of the plant are approximately equal.

  4. Generation of red fluorescent protein transgenic dogs.

    PubMed

    Hong, So Gun; Kim, Min Kyu; Jang, Goo; Oh, Hyun Ju; Park, Jung Eun; Kang, Jung Taek; Koo, Ok Jae; Kim, Teoan; Kwon, Mo Sun; Koo, Bon Chul; Ra, Jeong Chan; Kim, Dae Yong; Ko, CheMyong; Lee, Byeong Chun

    2009-05-01

    Dogs (Canis familiaris) share many common genetic diseases with humans and development of disease models using a transgenic approach has long been awaited. However, due to the technical difficulty in obtaining fertilizable eggs and the unavailability of embryonic stem cells, no transgenic dog has been generated. Canine fetal fibroblasts were stably transfected with a red fluorescent protein (RFP) gene-expressing construct using retrovirus gene delivery method. Somatic cell nuclear transfer was then employed to replace the nucleus of an oocyte with the nucleus of the RFP-fibroblasts. Using this approach, we produced the first generation of transgenic dogs with four female and two male expressing RFP.

  5. A comparative study of element concentrations and binding in transgenic and non-transgenic soybean seeds.

    PubMed

    Mataveli, Lidiane Raquel Verola; Pohl, Pawel; Mounicou, Sandra; Arruda, Marco Aurélio Zezzi; Szpunar, Joanna

    2010-12-01

    Transgenic and non-transgenic soybean seeds were compared in terms of total element concentrations, behavior of elements during sequential extraction fractionation and element bioaccessibility using an in vitro simulated gastrointestinal digestion. The analysis were carried out by ICP-sector field-MS or size-exclusion ICP-MS (25 elements in concentrations varying from ng g⁻¹ to the % level). It seems that transgenic and non-transgenic soybean seeds exhibit statistically significant differences in concentrations of Cu, Fe and Sr, which are also reflected by element contents in water extracts and residues. Additionally, contributions of bioaccessible fractions of Cu, Fe and other elements (Mn, S, Zn) for transgenic soybean seeds appear to be larger than those found in non-transgenic soybean seeds.

  6. Growth and physiological responses of isohydric and anisohydric poplars to drought.

    PubMed

    Attia, Ziv; Domec, Jean-Christophe; Oren, Ram; Way, Danielle A; Moshelion, Menachem

    2015-07-01

    Understanding how different plants prioritize carbon gain and drought vulnerability under a variable water supply is important for predicting which trees will maximize woody biomass production under different environmental conditions. Here, Populus balsamifera (BS, isohydric genotype), P. simonii (SI, previously uncharacterized stomatal behaviour), and their cross, P. balsamifera x simonii (BSxSI, anisohydric genotype) were studied to assess the physiological basis for biomass accumulation and water-use efficiency across a range of water availabilities. Under ample water, whole plant stomatal conductance (gs), transpiration (E), and growth rates were higher in anisohydric genotypes (SI and BSxSI) than in isohydric poplars (BS). Under drought, all genotypes regulated the leaf to stem water potential gradient via changes in gs, synchronizing leaf hydraulic conductance (Kleaf) and E: isohydric plants reduced Kleaf, gs, and E, whereas anisohydric genotypes maintained high Kleaf and E, which reduced both leaf and stem water potentials. Nevertheless, SI poplars reduced their plant hydraulic conductance (Kplant) during water stress and, unlike, BSxSI plants, recovered rapidly from drought. Low gs of the isohydric BS under drought reduced CO2 assimilation rates and biomass potential under moderate water stress. While anisohydric genotypes had the fastest growth under ample water and higher photosynthetic rates under increasing water stress, isohydric poplars had higher water-use efficiency. Overall, the results indicate three strategies for how closely related biomass species deal with water stress: survival-isohydric (BS), sensitive-anisohydric (BSxSI), and resilience-anisohydric (SI). Implications for woody biomass growth, water-use efficiency, and survival under variable environmental conditions are discussed.

  7. Growth and physiological responses of isohydric and anisohydric poplars to drought.

    PubMed

    Attia, Ziv; Domec, Jean-Christophe; Oren, Ram; Way, Danielle A; Moshelion, Menachem

    2015-07-01

    Understanding how different plants prioritize carbon gain and drought vulnerability under a variable water supply is important for predicting which trees will maximize woody biomass production under different environmental conditions. Here, Populus balsamifera (BS, isohydric genotype), P. simonii (SI, previously uncharacterized stomatal behaviour), and their cross, P. balsamifera x simonii (BSxSI, anisohydric genotype) were studied to assess the physiological basis for biomass accumulation and water-use efficiency across a range of water availabilities. Under ample water, whole plant stomatal conductance (gs), transpiration (E), and growth rates were higher in anisohydric genotypes (SI and BSxSI) than in isohydric poplars (BS). Under drought, all genotypes regulated the leaf to stem water potential gradient via changes in gs, synchronizing leaf hydraulic conductance (Kleaf) and E: isohydric plants reduced Kleaf, gs, and E, whereas anisohydric genotypes maintained high Kleaf and E, which reduced both leaf and stem water potentials. Nevertheless, SI poplars reduced their plant hydraulic conductance (Kplant) during water stress and, unlike, BSxSI plants, recovered rapidly from drought. Low gs of the isohydric BS under drought reduced CO2 assimilation rates and biomass potential under moderate water stress. While anisohydric genotypes had the fastest growth under ample water and higher photosynthetic rates under increasing water stress, isohydric poplars had higher water-use efficiency. Overall, the results indicate three strategies for how closely related biomass species deal with water stress: survival-isohydric (BS), sensitive-anisohydric (BSxSI), and resilience-anisohydric (SI). Implications for woody biomass growth, water-use efficiency, and survival under variable environmental conditions are discussed. PMID:25954045

  8. The Metagenome of an Anaerobic Microbial Community Decomposing Poplar Wood Chips

    PubMed Central

    van der Lelie, Daniel; Taghavi, Safiyh; McCorkle, Sean M.; Li, Luen-Luen; Malfatti, Stephanie A.; Monteleone, Denise; Donohoe, Bryon S.; Ding, Shi-You; Adney, William S.; Himmel, Michael E.; Tringe, Susannah G.

    2012-01-01

    This study describes the composition and metabolic potential of a lignocellulosic biomass degrading community that decays poplar wood chips under anaerobic conditions. We examined the community that developed on poplar biomass in a non-aerated bioreactor over the course of a year, with no microbial inoculation other than the naturally occurring organisms on the woody material. The composition of this community contrasts in important ways with biomass-degrading communities associated with higher organisms, which have evolved over millions of years into a symbiotic relationship. Both mammalian and insect hosts provide partial size reduction, chemical treatments (low or high pH environments), and complex enzymatic ‘secretomes’ that improve microbial access to cell wall polymers. We hypothesized that in order to efficiently degrade coarse untreated biomass, a spontaneously assembled free-living community must both employ alternative strategies, such as enzymatic lignin depolymerization, for accessing hemicellulose and cellulose and have a much broader metabolic potential than host-associated communities. This would suggest that such a community would make a valuable resource for finding new catalytic functions involved in biomass decomposition and gaining new insight into the poorly understood process of anaerobic lignin depolymerization. Therefore, in addition to determining the major players in this community, our work specifically aimed at identifying functions potentially involved in the depolymerization of cellulose, hemicelluloses, and lignin, and to assign specific roles to the prevalent community members in the collaborative process of biomass decomposition. A bacterium similar to Magnetospirillum was identified among the dominant community members, which could play a key role in the anaerobic breakdown of aromatic compounds. We suggest that these compounds are released from the lignin fraction in poplar hardwood during the decay process, which would point

  9. Hybrid poplar plantations are suitable habitat for reintroduced forest herbs with conservation status.

    PubMed

    Boothroyd-Roberts, Kathleen; Gagnon, Daniel; Truax, Benoit

    2013-01-01

    Plantations of fast-growing tree species may be of use in conservation by accelerating the restoration of forest habitat on abandoned farmland and increasing connectivity in fragmented landscapes. The objective of this study was to determine if hybrid poplar plantations can be suitable habitats for the reintroduction of native forest plant species and, if so, which abiotic factors predict successful reintroduction. Four species of forest herb species (Trillium grandiflorum, Sanguinaria canadensis, Maianthemum racemosum, Asarum canadense), of which three have legal conservation status, were transplanted into experimental plantations of two hybrid poplar clones and nearby second-growth woodlots at six sites in southern Quebec, Canada. The transplanted individuals were protected from deer browsing with exclusion cages. After two years, the plant responses of all four species were stable or increased over two years in both types of hybrid poplar plantations. Sanguinaria showed a better response in the plantations than in the woodlots, preferring the rich post-agricultural soils of the plantations with low C:N ratios. Asarum and Maianthemum showed no significant difference between stand types, while Trillium grew better in the woodlots than in the plantations. Much of the variability in the response of the latter three species was unexplained by the measured environmental variables. These results suggest that certain forest herb species can be reintroduced as juvenile plants into plantations, knowing that their spontaneous recolonization is often limited by dispersal and/or seedling establishment. Plantations could also contribute to the conservation of biodiversity by providing an environment for the cultivation of forest herb species as an alternative to their destructive harvest from natural populations.

  10. Challenging synergistic activity of poplar-bacteria association for the Cd phytostabilization.

    PubMed

    C, Cocozza; D, Trupiano; G, Lustrato; G, Alfano; D, Vitullo; A, Falasca; T, Lomaglio; V, De Felice; G, Lima; G, Ranalli; S, Scippa; R, Tognetti

    2015-12-01

    The synergistic activity between plants and microorganisms may contribute to the implementation of proactive management strategies in the stabilization of contaminated sites, although heavy metals, such as cadmium (Cd), are potentially toxic to them. The aim of this study was to evaluate the degree of tolerance to Cd contamination (supplying twice 40 mg kg(-1) of Cd) in poplar cuttings [clone I-214, P. × euramericana (Dode) Guinier] inoculated or not with two concentrations of Serratia marcescens strain (1 × 10(7) CFU/g and 2 × 10(7) CFU/g of potting mix). The response of the plant-bacteria system to excess Cd was investigated with special reference to the structural traits of plants and the functional efficiency of bacteria. Bacterial colonization and substrate components were previously assessed in order to define the best solution for formulating the experimental plant growth media. The tested plant-bacteria association, especially when bacteria were provided in double concentration, stimulated specific tolerance mechanisms to Cd through the promotion of the poplar growth. Inoculated plants produced larger leaves and increased stem diameter, while roots grew longer and wider in Cd-treated plants. The effect of bacterial inoculum on plant growth traits and metal partitioning in plant organs was assessed in order to define the potential of this poplar clone to be a suitable candidate for phytostabilization of Cd-contaminated soil. The final effect of the inoculation with bacteria, which alleviated the metal load and Cd phytotoxicity due to their bioaccumulation ability, suggests promising phytostabilization potential of these plant-bacteria associations.

  11. Challenging synergistic activity of poplar-bacteria association for the Cd phytostabilization.

    PubMed

    C, Cocozza; D, Trupiano; G, Lustrato; G, Alfano; D, Vitullo; A, Falasca; T, Lomaglio; V, De Felice; G, Lima; G, Ranalli; S, Scippa; R, Tognetti

    2015-12-01

    The synergistic activity between plants and microorganisms may contribute to the implementation of proactive management strategies in the stabilization of contaminated sites, although heavy metals, such as cadmium (Cd), are potentially toxic to them. The aim of this study was to evaluate the degree of tolerance to Cd contamination (supplying twice 40 mg kg(-1) of Cd) in poplar cuttings [clone I-214, P. × euramericana (Dode) Guinier] inoculated or not with two concentrations of Serratia marcescens strain (1 × 10(7) CFU/g and 2 × 10(7) CFU/g of potting mix). The response of the plant-bacteria system to excess Cd was investigated with special reference to the structural traits of plants and the functional efficiency of bacteria. Bacterial colonization and substrate components were previously assessed in order to define the best solution for formulating the experimental plant growth media. The tested plant-bacteria association, especially when bacteria were provided in double concentration, stimulated specific tolerance mechanisms to Cd through the promotion of the poplar growth. Inoculated plants produced larger leaves and increased stem diameter, while roots grew longer and wider in Cd-treated plants. The effect of bacterial inoculum on plant growth traits and metal partitioning in plant organs was assessed in order to define the potential of this poplar clone to be a suitable candidate for phytostabilization of Cd-contaminated soil. The final effect of the inoculation with bacteria, which alleviated the metal load and Cd phytotoxicity due to their bioaccumulation ability, suggests promising phytostabilization potential of these plant-bacteria associations. PMID:26268621

  12. Ecological risk assessment of the benthic invertebrate community of the Clinch River/Poplar Creek system

    SciTech Connect

    Jones, D.; Suter, G.; Barnthouse, L.; Efroymson, R.; Field, J.; Gonzalez, A.

    1995-12-31

    The CERCLA remedial investigation for the Clinch River/Poplar Creek included the benthic invertebrate community as an endpoint. The assessment endpoint was defined as a 20% reduction in species richness or abundance of the benthic invertebrate community in the Poplar Creek embayment or in any of three reaches of the Clinch River. Screening of chemical concentrations in sediment and pore water against benchmarks determined that 38 chemicals were contaminants of potential ecological concern (COPECs). Pore water COPECs were limited to fifteen metals, benzoic acid, and bis(2-ethylhexyl)phthalate. Many COPEC concentrations exceeded benchmarks by two to three orders of magnitude. Mercury was the primary sediment COPEC, although PCBs, PAHs, and other metals were also potentially toxic. Comparison of the distributions of COPEC concentrations with the distributions of literature toxicity values indicated widespread toxicity of several COPECs. Sediment toxicity tests indicated that a few sediment samples were toxic, but in general very little toxicity and no clear spatial trends were observed. Whole sediment tests were more sensitive than pore water tests. This may indicate that sediment-associated contaminants contribute more to risks. The benthic invertebrate community data were evaluated using canonical discriminant analyses. Communities in the Operable Unit (OU) were less diverse than in lower Tennessee Valley mainstem reservoirs, but similar to other upper valley reservoir communities. Abundance and taxa richness were reduced at some sites, but were not consistently reflective of contaminant sources. Decreased taxa richness and abundance in upper Poplar Creek may indicate contaminant sources upstream of the OU. These conflicting results are a challenge to ecological risk characterization based on weight-of-evidence. The process of weighing the evidence will be presented.

  13. The metagenome of an anaerobic microbial community decomposing poplar wood chips

    SciTech Connect

    van der Lelie D.; Taghavi, S.; McCorkle, S. M.; Li, L.-L.; Malfatti, S. A.; Monteleone, D.; Donohoe, B. S.; Ding, S.-Y.; Adney, W. S.; Himmel, M. E.; Tringe, S. G.

    2012-05-01

    This study describes the composition and metabolic potential of a lignocellulosic biomass degrading community that decays poplar wood chips under anaerobic conditions. We examined the community that developed on poplar biomass in a non-aerated bioreactor over the course of a year, with no microbial inoculation other than the naturally occurring organisms on the woody material. The composition of this community contrasts in important ways with biomass-degrading communities associated with higher organisms, which have evolved over millions of years into a symbiotic relationship. Both mammalian and insect hosts provide partial size reduction, chemical treatments (low or high pH environments), and complex enzymatic 'secretomes' that improve microbial access to cell wall polymers. We hypothesized that in order to efficiently degrade coarse untreated biomass, a spontaneously assembled free-living community must both employ alternative strategies, such as enzymatic lignin depolymerization, for accessing hemicellulose and cellulose and have a much broader metabolic potential than host-associated communities. This would suggest that such a community would make a valuable resource for finding new catalytic functions involved in biomass decomposition and gaining new insight into the poorly understood process of anaerobic lignin depolymerization. Therefore, in addition to determining the major players in this community, our work specifically aimed at identifying functions potentially involved in the depolymerization of cellulose, hemicelluloses, and lignin, and to assign specific roles to the prevalent community members in the collaborative process of biomass decomposition. A bacterium similar to Magnetospirillum was identified among the dominant community members, which could play a key role in the anaerobic breakdown of aromatic compounds. We suggest that these compounds are released from the lignin fraction in poplar hardwood during the decay process, which would point to

  14. Hypoxia Affects Nitrogen Uptake and Distribution in Young Poplar (Populus × canescens) Trees

    PubMed Central

    Liu, Bin; Rennenberg, Heinz; Kreuzwieser, Jürgen

    2015-01-01

    The present study with young poplar trees aimed at characterizing the effect of O2 shortage in the soil on net uptake of NO3- and NH4+ and the spatial distribution of the N taken up. Moreover, we assessed biomass increment as well as N status of the trees affected by O2 deficiency. For this purpose, an experiment was conducted in which hydroponically grown young poplar trees were exposed to hypoxic and normoxic (control) conditions for 14 days. 15N-labelled NO3- and NH4+ were used to elucidate N uptake and distribution of currently absorbed N and N allocation rates in the plants. Whereas shoot biomass was not affected by soil O2 deficiency, it significantly reduced root biomass and, consequently, the root-to-shoot ratio. Uptake of NO3- but not of NH4+ by the roots of the trees was severely impaired by hypoxia. As a consequence of reduced N uptake, the N content of all poplar tissues was significantly diminished. Under normoxic control conditions, the spatial distribution of currently absorbed N and N allocation rates differed depending on the N source. Whereas NO3- derived N was mainly transported to the younger parts of the shoot, particularly to the developing and young mature leaves, N derived from NH4+ was preferentially allocated to older parts of the shoot, mainly to wood and bark. Soil O2 deficiency enhanced this differential allocation pattern. From these results we assume that NO3- was assimilated in developing tissues and preferentially used to maintain growth and ensure plant survival under hypoxia, whereas NH4+ based N was used for biosynthesis of storage proteins in bark and wood of the trees. Still, further studies are needed to understand the mechanistic basis as well as the eco-physiological advantages of such differential allocation patterns. PMID:26308462

  15. Growth and physiological responses of isohydric and anisohydric poplars to drought

    PubMed Central

    Attia, Ziv; Domec, Jean-Christophe; Oren, Ram; Way, Danielle A.; Moshelion, Menachem

    2015-01-01

    Understanding how different plants prioritize carbon gain and drought vulnerability under a variable water supply is important for predicting which trees will maximize woody biomass production under different environmental conditions. Here, Populus balsamifera (BS, isohydric genotype), P. simonii (SI, previously uncharacterized stomatal behaviour), and their cross, P. balsamifera x simonii (BSxSI, anisohydric genotype) were studied to assess the physiological basis for biomass accumulation and water-use efficiency across a range of water availabilities. Under ample water, whole plant stomatal conductance (gs), transpiration (E), and growth rates were higher in anisohydric genotypes (SI and BSxSI) than in isohydric poplars (BS). Under drought, all genotypes regulated the leaf to stem water potential gradient via changes in gs, synchronizing leaf hydraulic conductance (Kleaf) and E: isohydric plants reduced Kleaf, gs, and E, whereas anisohydric genotypes maintained high Kleaf and E, which reduced both leaf and stem water potentials. Nevertheless, SI poplars reduced their plant hydraulic conductance (Kplant) during water stress and, unlike, BSxSI plants, recovered rapidly from drought. Low gs of the isohydric BS under drought reduced CO2 assimilation rates and biomass potential under moderate water stress. While anisohydric genotypes had the fastest growth under ample water and higher photosynthetic rates under increasing water stress, isohydric poplars had higher water-use efficiency. Overall, the results indicate three strategies for how closely related biomass species deal with water stress: survival-isohydric (BS), sensitive-anisohydric (BSxSI), and resilience-anisohydric (SI). Implications for woody biomass growth, water-use efficiency, and survival under variable environmental conditions are discussed. PMID:25954045

  16. Analysis of the impact of biomechanical traits of European black Poplar on riverbank flow resistance

    NASA Astrophysics Data System (ADS)

    Battista Chirico, Giovanni; Saulino, Luigi; Pasquino, Vittorio; Villani, Paolo; Rita, Angelo; Todaro, Luigi; Saracino, Antonio

    2016-04-01

    Predicting the effects of riparian plants on river flow dynamics is fundamental for an appropriate river management. Riparian woody vegetation enhances bank cohesion and provides ecosystem services by mitigating nutrient and sediment loads to the river flow and enhancing biodiversity. However riparian trees also contribute to river flow resistance and thus can have a significant impact on flow dynamics during flood events. The flow-plant interaction mainly depends on plant morphological characters (e.g. diameter, height, canopy size, foliage density) and biomechanical properties, such as its flexural rigidity. This study aims at testing the hypothesis that the hydrodynamic behaviour of the European black Poplar (∖textit{Populus nigra} L.), a common woody riparian plant, is influenced by specific biomechanical traits developed as result of its adaptation to different river ecosystems. We examine the morphological and biomechanical properties of living stems of black Poplar sampled in two different riverine environments in Southern Italy located only a few kilometres apart. The two sample sets of living stems exhibit similar morphological traits but significantly different Young module of elasticity. We compared the drag forces that the flow would exert on these two different sets of plants for a wide range of flow velocities, by employing a numerical model that accounts for the bending behaviour of the woody plant due to the hydrodynamic load, under the hypothesis of complete submergence. A Monte Carlo approach was applied in order to account for the stochastic variability of the morphological and mechanical parameters affecting plant biomechanical behaviour. We identified a threshold value of the plant diameter, above which the two sets of European black Poplars are subjected to drag forces that differ by more than 25{∖%} on average, for flow velocities larger than 1 m/s.

  17. Hydrologic data for the East Poplar oil field, Fort Peck Indian Reservation, Northeastern Montana

    USGS Publications Warehouse

    Thamke, J.N.; Craigg, S.D.; Mendes, T.M.

    1996-01-01

    This report presents selected hydrologic data for the East Poplar oil field, located in the south-central part of the Fort Peck Indian Reservation in northeastern Montana. Data about the occurrence, quantity, and quality of ground and surface water are presented in tabular form. The tables contain records of privately owned wells (active and abandoned), monitoring wells installed by the U.S. Geological Survey and Montana Bureau of Mines and Geology, oil wells, and brine-injection wells; lithologic descriptions of drill cuttings and well-completion data from monitoring wells; data from two aquifer tests conducted in Quaternary alluvial and glacial deposits; chemical quality of ground water; and information on the quantity and chemical quality of surface water. Records of electromagnetic geophysical measurements collected throughout an area of about 20 square miles of the study area are compiled and included on a floppy disk. Illustrations in this report contain information about study area location, site- numbering system, general physical and cultural features, and construction of monitoring wells installed by the U.S. Geological Survey. plate-sized map presents additional information about privately owned wells, monitoring wells, oil wells, brine-injections wells, surface-water data-collection sites, and area of electromagnetic data collection. The data presented in this report provide a base with which to better define and interpret the occurrence, quantity, and quality of ground and surface water in the vicinity of the Poplar River Valley in the south-central part of the Fort Peck Indian Reservation. The data can be used to help delineate the occurrence of brine and saline water in Quaternary alluvial and glacial deposits in the East Poplar oil field.

  18. An identification of the East Fork Poplar Creek floodplain, Anderson and Roane Counties, Tennessee

    SciTech Connect

    1992-12-01

    The work in this report was conducted by the US Army Corps of Engineers, Nashville District, during the period November 1991 through July 1992. The purpose of this study is to identify the East Fork Poplar Creek (EFPC) floodplain. This information is required as part of the remedial action plans for removal or containment of contamination within the EFPC floodplain. EFPC and a portion of its floodplain have been contaminated as a result of operations and accidental releases at the Department of Energy`s Y-12 Plant. Mercury is the major contaminant found in EFPC and its floodplain.

  19. Effect of lignin content on changes occurring in poplar cellulose ultrastructure during dilute acid pretreatment

    DOE PAGESBeta

    Sun, Qining; Foston, Marcus; Meng, Xianzhi; Sawada, Daisuke; Pingali, Sai Venkatesh; O’Neill, Hugh M.; Li, Hongjia; Wyman, Charles E.; Langan, Paul; Ragauskas, Art J.; et al

    2014-10-14

    Obtaining a better understanding of the complex mechanisms occurring during lignocellulosic deconstruction is critical to the continued growth of renewable biofuel production. A key step in bioethanol production is thermochemical pretreatment to reduce plant cell wall recalcitrance for downstream processes. Previous studies of dilute acid pretreatment (DAP) have shown significant changes in cellulose ultrastructure that occur during pretreatment, but there is still a substantial knowledge gap with respect to the influence of lignin on these cellulose ultrastructural changes. This study was designed to assess how the presence of lignin influences DAP-induced changes in cellulose ultrastructure, which might ultimately have largemore » implications with respect to enzymatic deconstruction efforts. Native, untreated hybrid poplar (Populus trichocarpa x Populus deltoids) samples and a partially delignified poplar sample (facilitated by acidic sodium chlorite pulping) were separately pretreated with dilute sulfuric acid (0.10 M) at 160°C for 15 minutes and 35 minutes, respectively . Following extensive characterization, the partially delignified biomass displayed more significant changes in cellulose ultrastructure following DAP than the native untreated biomass. With respect to the native untreated poplar, delignified poplar after DAP (in which approximately 40% lignin removal occurred) experienced: increased cellulose accessibility indicated by increased Simons’ stain (orange dye) adsorption from 21.8 to 72.5 mg/g, decreased cellulose weight-average degree of polymerization (DPw) from 3087 to 294 units, and increased cellulose crystallite size from 2.9 to 4.2 nm. These changes following DAP ultimately increased enzymatic sugar yield from 10 to 80%. We conclude that, overall, the results indicate a strong influence of lignin content on cellulose ultrastructural changes occurring during DAP. With the reduction of lignin content during DAP, the enlargement of

  20. Access of cellulase to cellulose and lignin for poplar solids produced by leading pretreatment technologies.

    PubMed

    Kumar, Rajeev; Wyman, Charles E

    2009-01-01

    Adsorption of cellulase on solids resulting from pretreatment of poplar wood by ammonia fiber expansion (AFEX), ammonia recycled percolation (ARP), controlled pH, dilute acid (DA), flowthrough (FT), lime, and sulfur dioxide (SO(2)) and pure Avicel glucan was measured at 4 degrees C, as were adsorption and desorption of cellulase and adsorption of beta-glucosidase for lignin left after enzymatic digestion of the solids from these pretreatments. From this, Langmuir adsorption parameters, cellulose accessibility to cellulase, and the effectiveness of cellulase adsorbed on poplar solids were estimated, and the effect of delignification on cellulase effectiveness was determined. Furthermore, Avicel hydrolysis inhibition by enzymatic and acid lignin of poplar solids was studied. Flowthrough pretreated solids showed the highest maximum cellulase adsorption capacity (sigma(solids) = 195 mg/g solid) followed by dilute acid (sigma(solids) = 170.0 mg/g solid) and lime pretreated solids (sigma(solids) = 150.8 mg/g solid), whereas controlled pH pretreated solids had the lowest (sigma(solids) = 56 mg/g solid). Lime pretreated solids also had the highest cellulose accessibility (sigma(cellulose) = 241 mg/g cellulose) followed by FT and DA. AFEX lignin had the lowest cellulase adsorption capacity (sigma(lignin) = 57 mg/g lignin) followed by dilute acid lignin (sigma(lignin) = 74 mg/g lignin). AFEX lignin also had the lowest beta-glucosidase capacity (sigma(lignin) = 66.6 mg/g lignin), while lignin from SO(2) (sigma(lignin) = 320 mg/g lignin) followed by dilute acid had the highest (301 mg/g lignin). Furthermore, SO(2) followed by dilute acid pretreated solids gave the highest cellulase effectiveness, but delignification enhanced cellulase effectiveness more for high pH than low pH pretreatments, suggesting that lignin impedes access of enzymes to xylan more than to glucan, which in turn affects glucan accessibility. In addition, lignin from enzymatic digestion of AFEX and dilute

  1. Genome-wide analysis of eukaryote thaumatin-like proteins (TLPs) with an emphasis on poplar

    PubMed Central

    2011-01-01

    Background Plant inducible immunity includes the accumulation of a set of defense proteins during infection called pathogenesis-related (PR) proteins, which are grouped into families termed PR-1 to PR-17. The PR-5 family is composed of thaumatin-like proteins (TLPs), which are responsive to biotic and abiotic stress and are widely studied in plants. TLPs were also recently discovered in fungi and animals. In the poplar genome, TLPs are over-represented compared with annual species and their transcripts strongly accumulate during stress conditions. Results Our analysis of the poplar TLP family suggests that the expansion of this gene family was followed by diversification, as differences in expression patterns and predicted properties correlate with phylogeny. In particular, we identified a clade of poplar TLPs that cluster to a single 350 kb locus of chromosome I and that are up-regulated by poplar leaf rust infection. A wider phylogenetic analysis of eukaryote TLPs - including plant, animal and fungi sequences - shows that TLP gene content and diversity increased markedly during land plant evolution. Mapping the reported functions of characterized TLPs to the eukaryote phylogenetic tree showed that antifungal or glycan-lytic properties are widespread across eukaryote phylogeny, suggesting that these properties are shared by most TLPs and are likely associated with the presence of a conserved acidic cleft in their 3D structure. Also, we established an exhaustive catalog of TLPs with atypical architectures such as small-TLPs, TLP-kinases and small-TLP-kinases, which have potentially developed alternative functions (such as putative receptor kinases for pathogen sensing and signaling). Conclusion Our study, based on the most recent plant genome sequences, provides evidence for TLP gene family diversification during land plant evolution. We have shown that the diverse functions described for TLPs are not restricted to specific clades but seem to be universal among

  2. Best management practices plan for the Lower East Fork Poplar Creek Operable Unit, Oak Ridge, Tennessee

    SciTech Connect

    1996-04-01

    This plan was prepared in support of the Phase II Remedial Design Report (DOE/OR/01-1449&D1) and in accordance with requirements under CERCLA to present the plan for best management practices to be followed during the remediation. This document provides the Environmental Restoration Program with information about spill prevention and control, water quality monitoring, good housekeeping practices, sediment and erosion control measures, and inspections and environmental compliance practices to be used during Phase II of the remediation project for the Lower East Fork Poplar Creek Operable Unit.

  3. Phasing Variants in Poplar Trees using a Hybrid of Short & Long Read Technologies

    SciTech Connect

    Schackwitz, Wendy; Martin, Joel; Lipzen, Anna; Pennacchio, Len; Tuskan, Gerald

    2013-03-26

    Poplar grow throughout the West coast & are adapted to extremely variable conditions. To examine what allows for this wide range of growth conditions, Jerry Tuskan's team has collected 1000 different individuals from British Columbia to California. In 2009, three Common Gardens were established where each individual was cloned in triplicate. Nearly all of these trees have been sequenced using short read technology, revealing a huge degree of variation in genotype. Correlating this genomic variation to phenotype would be greatly be strengthened if the variants could be phased into long haplotype blocks.

  4. Hexahydro-1,3,5-trinitro-1,3,5-triazine translocation in poplar trees

    SciTech Connect

    Thompson, P.L.; Ramer, L.A.; Schnoor, J.L.

    1999-02-01

    This article evaluates the translocation of the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in hybrid poplar trees (Populus deltoides x nigra, DN34) grown in hydroponic solutions. Mass balances with [U-{sup 14}C]RDX were used to assess RDX translocation. Up to 60% of the RDX uptaken by the tree accumulated in leaf tissues. Analysis of plant extracts by high-performance liquid chromatography equipped with radiochemical detection indicated that RDX was not significantly transformed during exposure periods of up to 7 d. The bioaccumulation of RDX may be an important concern for phytoremediation efforts.

  5. Remedial investigation/feasibility study of the Clinch River/Poplar Creek operable unit. Volume 5

    SciTech Connect

    1996-03-01

    This volume is in support of the findings of an investigation into contamination of the Clinch River and Poplar Creek near the Oak Ridge Reservation (for more than 50 years, various hazardous and radioactive substances have been released to the environment as a result of operations and waste management activities there). It addresses the quality assurance objectives for measuring the data, presents selected historical data, contains data from several discrete water characterization studies, provides data supporting the sediment characterization, and contains data related to several biota characterization studies.

  6. Effect of lignin content on changes occurring in poplar cellulose ultrastructure during dilute acid pretreatment

    SciTech Connect

    Sun, Qining; Foston, Marcus; Meng, Xianzhi; Sawada, Daisuke; Pingali, Sai Venkatesh; O’Neill, Hugh M.; Li, Hongjia; Wyman, Charles E.; Langan, Paul; Ragauskas, Art J.; Kumar, Rajeev

    2014-10-14

    Obtaining a better understanding of the complex mechanisms occurring during lignocellulosic deconstruction is critical to the continued growth of renewable biofuel production. A key step in bioethanol production is thermochemical pretreatment to reduce plant cell wall recalcitrance for downstream processes. Previous studies of dilute acid pretreatment (DAP) have shown significant changes in cellulose ultrastructure that occur during pretreatment, but there is still a substantial knowledge gap with respect to the influence of lignin on these cellulose ultrastructural changes. This study was designed to assess how the presence of lignin influences DAP-induced changes in cellulose ultrastructure, which might ultimately have large implications with respect to enzymatic deconstruction efforts. Native, untreated hybrid poplar (Populus trichocarpa x Populus deltoids) samples and a partially delignified poplar sample (facilitated by acidic sodium chlorite pulping) were separately pretreated with dilute sulfuric acid (0.10 M) at 160°C for 15 minutes and 35 minutes, respectively . Following extensive characterization, the partially delignified biomass displayed more significant changes in cellulose ultrastructure following DAP than the native untreated biomass. With respect to the native untreated poplar, delignified poplar after DAP (in which approximately 40% lignin removal occurred) experienced: increased cellulose accessibility indicated by increased Simons’ stain (orange dye) adsorption from 21.8 to 72.5 mg/g, decreased cellulose weight-average degree of polymerization (DPw) from 3087 to 294 units, and increased cellulose crystallite size from 2.9 to 4.2 nm. These changes following DAP ultimately increased enzymatic sugar yield from 10 to 80%. We conclude that, overall, the results indicate a strong influence of lignin content on cellulose ultrastructural changes occurring during DAP. With the reduction of lignin content during DAP, the enlargement of

  7. [Review of transgenic crop breeding in China].

    PubMed

    Huang, Dafang

    2015-06-01

    The development history and fundamental experience of transgenic crops (Genetically modified crops) breeding in China for near 30 years were reviewed. It was illustrated that a scientific research, development and industrialization system of transgenic crops including gene discovery, transformation, variety breeding, commercialization, application and biosafety assessment has been initially established which was few in number in the world. The research innovative capacity of transgenic cotton, rice and corn has been lifted. The research features as well as relative advantages have been initially formed. The problems and challenges of transgenic crop development were discussed. In addition, three suggestions of promoting commercialization, speeding up implementation of the Major National Project of GM Crops, and enhancing science communication were made. PMID:26672365

  8. AN APPROACH TO TRANSGENIC CROP MONITORING

    EPA Science Inventory

    Remote sensing by aerial or satellite images may provide a method of identifying transgenic pesticidal crop distribution in the landscape. Genetically engineered crops containing bacterial gene(s) that express an insecticidal protein from Bacillus thuringiensis (Bt) are regulated...

  9. Transgenic plants with enhanced growth characteristics

    DOEpatents

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2016-09-06

    The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

  10. Phenotyping transgenic wheat for drought resistance.

    PubMed

    Saint Pierre, Carolina; Crossa, José L; Bonnett, David; Yamaguchi-Shinozaki, Kazuko; Reynolds, Matthew P

    2012-03-01

    Realistic experimental protocols to screen for drought adaptation in controlled conditions are crucial if high throughput phenotyping is to be used for the identification of high performance lines, and is especially important in the evaluation of transgenes where stringent biosecurity measures restrict the frequency of open field trials. Transgenic DREB1A-wheat events were selected under greenhouse conditions by evaluating survival and recovery under severe drought (SURV) as well as for water use efficiency (WUE). Greenhouse experiments confirmed the advantages of transgenic events in recovery after severe water stress. Under field conditions, the group of transgenic lines did not generally outperform the controls in terms of grain yield under water deficit. However, the events selected for WUE were identified as lines that combine an acceptable yield-even higher yield (WUE-11) under well irrigated conditions-and stable performance across the different environments generated by the experimental treatments.

  11. Transgenic Wheat, Barley and Oats: Future Prospects

    NASA Astrophysics Data System (ADS)

    Dunwell, Jim M.

    Following the success of transgenic maize and rice, methods have now been developed for the efficient introduction of genes into wheat, barley and oats. This review summarizes the present position in relation to these three species, and also uses information from field trial databases and the patent literature to assess the future trends in the exploitation of transgenic material. This analysis includes agronomic traits and also discusses opportunities in expanding areas such as biofuels and biopharming.

  12. Transgenic animals resistant to infectious diseases.

    PubMed

    Tiley, L

    2016-04-01

    The list of transgenic animals developed to test ways of producing livestock resistant to infectious disease continues to grow. Although the basic techniques for generating transgenic animals have not changed very much in the ten years since they were last reviewed for the World Organisation for Animal Health, one recent fundamental technological advance stands to revolutionise genome engineering. The advent of technically simple and efficient site-specific gene targeting has profound implications for genetically modifying livestock species.

  13. [Detection of transgenic crop with gene chip].

    PubMed

    Huang, Ying-Chun; Sun, Chun-Yun; Feng, Hong; Hu, Xiao-Dong; Yin, Hai-Bin

    2003-05-01

    Some selected available sequences of reporter genes,resistant genes, promoters and terminators are amplified by PCR for the probes of transgenic crop detection gene chip. These probes are arrayed at definite density and printed on the surface of amino-slides by bioRobot MicroGrid II. Results showed that gene chip worked quickly and correctly, when transgenic rice, pawpaw,maize and soybean were applied. PMID:15639876

  14. Transgene flow: Facts, speculations and possible countermeasures

    PubMed Central

    Ryffel, Gerhart U

    2014-01-01

    Convincing evidence has accumulated that unintended transgene escape occurs in oilseed rape, maize, cotton and creeping bentgrass. The escaped transgenes are found in variant cultivars, in wild type plants as well as in hybrids of sexually compatible species. The fact that in some cases stacked events are present that have not been planted commercially, implies unintended recombination of transgenic traits. As the consequences of this continuous transgene escape for the ecosystem cannot be reliably predicted, I propose to use more sophisticated approaches of gene technology in future. If possible GM plants should be constructed using either site-directed mutagenesis or cisgenic strategies to avoid the problem of transgene escape. In cases where a transgenic trait is needed, efficient containment should be the standard approach. Various strategies available or in development are discussed. Such a cautious approach in developing novel types of GM crops will enhance the sustainable potential of GM crops and thus increase the public trust in green gene technology. PMID:25523171

  15. Transgene flow: facts, speculations and possible countermeasures.

    PubMed

    Ryffel, Gerhart U

    2014-01-01

    Convincing evidence has accumulated that unintended transgene escape occurs in oilseed rape, maize, cotton and creeping bentgrass. The escaped transgenes are found in variant cultivars, in wild type plants as well as in hybrids of sexually compatible species. The fact that in some cases stacked events are present that have not been planted commercially, implies unintended recombination of transgenic traits. As the consequences of this continuous transgene escape for the ecosystem cannot be reliably predicted, I propose to use more sophisticated approaches of gene technology in future. If possible GM plants should be constructed using either site-directed mutagenesis or cisgenic strategies to avoid the problem of transgene escape. In cases where a transgenic trait is needed, efficient containment should be the standard approach. Various strategies available or in development are discussed. Such a cautious approach in developing novel types of GM crops will enhance the sustainable potential of GM crops and thus increase the public trust in green gene technology. PMID:25523171

  16. Ozone exposure and flux-based response functions for photosynthetic traits in wheat, maize and poplar.

    PubMed

    Bagard, Matthieu; Jolivet, Yves; Hasenfratz-Sauder, Marie-Paule; Gérard, Joëlle; Dizengremel, Pierre; Le Thiec, Didier

    2015-11-01

    Ozone exposure- and dose-response relationships based on photosynthetic leaf traits (CO2 assimilation, chlorophyll content, Rubisco and PEPc activities) were established for wheat, maize and poplar plants grown in identical controlled conditions, providing a comparison between crop and tree species, as well as between C3 and C4 plants. Intra-specific variability was addressed by comparing two wheat cultivars with contrasting ozone tolerance. Depending on plant models and ozone levels, first-order, second-order and segmented linear regression models were used to derive ozone response functions. Overall, flux-based functions appeared superior to exposure-based functions in describing the data, but the improvement remained modest. The best fit was obtained using the POD0.5 for maize and POD3 for poplar. The POD6 appeared relevant for wheat, although intervarietal differences were found. Our results suggest that taking into account the dynamics of leaf antioxidant capacity could improve current methods for ozone risk assessment for plants.

  17. Drought-induced xylem pit membrane damage in aspen and balsam poplar.

    PubMed

    Hillabrand, Rachel M; Hacke, Uwe G; Lieffers, Victor J

    2016-10-01

    Drought induces an increase in a tree's vulnerability to a loss of its hydraulic conductivity in many tree species, including two common in western Canada, trembling aspen (Populus tremuloides) and balsam poplar (Populus balsamifera). Termed 'cavitation fatigue' or 'air-seeding fatigue', the mechanism of this phenomenon is not well understood, but hypothesized to be a result of damage to xylem pit membranes. To examine the validity of this hypothesis, the effect of drought on the porosity of pit membranes in aspen and balsam poplar was investigated. Controlled drought and bench dehydration treatments were used to induce fatigue and scanning electron microscopy (SEM) was used to image pit membranes for relative porosity evaluations from air-dried samples after ethanol dehydration. A significant increase in the diameter of the largest pore was found in the drought and dehydration treatments of aspen, while an increase in the percentage of porous pit membranes was found in the dehydration treatments of both species. Additionally, the location of the largest pore per pit membrane was observed to tend toward the periphery of the membrane. PMID:27342227

  18. Comparative Sugar Recovery and Fermentation Data Following Pretreatment of Poplar Wood by Leading Technologies

    SciTech Connect

    Wyman, C. E.; Dale, B. E.; Elander, R. T.; Holtzapple, M.; Ladisch, M. R.; Lee, Y. Y.; Mitchinson, C.; Saddler, J. N.

    2009-01-01

    Through a Biomass Refining Consortium for Applied Fundamentals and Innovation among Auburn University, Dartmouth College, Michigan State University, the National Renewable Energy Laboratory, Purdue University, Texas A&M University, the University of British Columbia, and the University of California at Riverside, leading pretreatment technologies based on ammonia fiber expansion, aqueous ammonia recycle, dilute sulfuric acid, lime, neutral pH, and sulfur dioxide were applied to a single source of poplar wood, and the remaining solids from each technology were hydrolyzed to sugars using the same enzymes. Identical analytical methods and a consistent material balance methodology were employed to develop comparative performance data for each combination of pretreatment and enzymes. Overall, compared to data with corn stover employed previously, the results showed that poplar was more recalcitrant to conversion to sugars and that sugar yields from the combined operations of pretreatment and enzymatic hydrolysis varied more among pretreatments. However, application of more severe pretreatment conditions gave good yields from sulfur dioxide and lime, and a recombinant yeast strain fermented the mixed stream of glucose and xylose sugars released by enzymatic hydrolysis of water washed solids from all pretreatments to ethanol with similarly high yields. An Agricultural and Industrial Advisory Board followed progress and helped steer the research to meet scientific and commercial needs.

  19. Local selection across a latitudinal gradient shapes nucleotide diversity in balsam poplar, Populus balsamifera L.

    PubMed

    Keller, Stephen R; Levsen, Nicholas; Ingvarsson, Pär K; Olson, Matthew S; Tiffin, Peter

    2011-08-01

    Molecular studies of adaptive evolution often focus on detecting selective sweeps driven by positive selection on a species-wide scale; however, much adaptation is local, particularly of ecologically important traits. Here, we look for evidence of range-wide and local adaptation at candidate genes for adaptive phenology in balsam poplar, Populus balsamifera, a widespread forest tree whose range extends across environmental gradients of photoperiod and growing season length. We examined nucleotide diversity of 27 poplar homologs of the flowering-time network-a group of genes that control plant developmental phenology through interactions with environmental cues such as photoperiod and temperature. Only one gene, ZTL2, showed evidence of reduced diversity and an excess of fixed replacement sites, consistent with a species-wide selective sweep. Two other genes, LFY and FRI, harbored high levels of nucleotide diversity and exhibited elevated differentiation between northern and southern accessions, suggesting local adaptation along a latitudinal gradient. Interestingly, FRI has also been identified as a target of local selection between northern and southern accessions of Arabidopsis thaliana, indicating that this gene may be commonly involved in ecological adaptation in distantly related species. Our findings suggest an important role for local selection shaping molecular diversity and reveal limitations of inferring molecular adaptation from analyses designed only to detect species-wide selective sweeps. PMID:21624997

  20. Influence of soil fertility and water stress on the ozone response of hybrid poplar trees

    SciTech Connect

    Harkov, R.; Brennan, E.

    1980-01-01

    Experiments were conducted to determine the role of soil fertility and water stress on the ozone response of hybrid poplar trees. Rooted cuttings of hybrid poplar clone number388 (Populus maximowiczii X P. trichocarpa) were grown in a filtered-air greenhouse in 4.73-L plastic pots containing a greenhouse potting mix. A slow release 18-6-12 NPK fertilizer was added to obtain four soil fertility levels. Although the nitrogen content of the foliage increased significantly, after 2 months of growth, neither linear growth nor percent dry weight was affected by these amendments. Trees with a foliar content of approximately 2.69% N were found to be more susceptible to ozone fumigation of 196 ..mu..g/m/sup 3/ for 6 hr than were trees with 1.53, 3.12, or 3.47% N. In the water stress experiment, withholding water from the test plants for 6-9 days reduced the relative water content in the foliage to 7-21%, respectively, below that of control plants, and protected the trees from a 6-hr fumigation at 196 ..mu..g/m/sup 3/. Visible water stress symptoms were not evident in plants from which water had been withheld for 6 days. These results are discussed as they pertain to susceptibility of urban trees to ozone damage.

  1. Physical and chemical characteristics of products from the torrefaction of yellow poplar (Liriodendron tulipifera).

    PubMed

    Kim, Young-Hun; Lee, Soo-Min; Lee, Hyoung-Woo; Lee, Jae-Won

    2012-07-01

    We investigated the characteristics of torrefied yellow poplar (Liriodendron tulipifera) depending on reaction time (30 min) and temperature (240-280 °C). The thermogravimetric, grindability and calorific value of torrefied biomass were analyzed. As the torrefaction temperature increased, the carbon content of torrefied biomass increased from 49.50% to 54.42%, while the hydrogen and oxygen contents decreased from 6.09% to 5.65% and 28.71% to 26.61%, respectively. The highest calorific value was 1233 kJ/kg when torrefaction was performed at 280 °C for 30 min. An overall increase in energy density and decrease in mass and energy yield was observed with the increase in torrefaction temperature. The analysis of thermal decomposition demonstrated that the hemicelluloses contained in torrefied biomass decreased with increasing torrefaction temperature, whereas cellulose and lignin were only slightly affected. The grindability of torrefied biomass was significantly improved when torrefaction was performed at high temperature. Torrefaction of yellow poplar improved the chemical and physical fuel properties of the biomass. PMID:22609665

  2. Interaction of drought and ozone exposure on isoprene emission from extensively cultivated poplar.

    PubMed

    Yuan, Xiangyang; Calatayud, Vicent; Gao, Feng; Fares, Silvano; Paoletti, Elena; Tian, Yuan; Feng, Zhaozhong

    2016-10-01

    The combined effects of ozone (O3 ) and drought on isoprene emission were studied for the first time. Young hybrid poplars (clone 546, Populus deltoides cv. 55/56 x P. deltoides cv. Imperial) were exposed to O3 (charcoal-filtered air, CF, and non-filtered air +40 ppb, E-O3 ) and soil water stress (well-watered, WW, and mild drought, MD, one-third irrigation) for 96 days. Consistent with light-saturated photosynthesis (Asat ), intercellular CO2 concentration (Ci ) and chlorophyll content, isoprene emission depended on drought, O3 , leaf position and sampling time. Drought stimulated emission (+38.4%), and O3 decreased it (-40.4%). Ozone increased the carbon cost per unit of isoprene emission. Ozone and drought effects were stronger in middle leaves (13th-15th from the apex) than in upper leaves (6th-8th). Only Asat showed a significant interaction between O3 and drought. When the responses were up-scaled to the entire-plant level, however, drought effects on total leaf area translated into around twice higher emission from WW plants in clean air than in E-O3 . Our results suggest that direct effects on plant emission rates and changes in total leaf area may affect isoprene emission from intensively cultivated hybrid poplar under combined MD and O3 exposure, with important feedbacks for air quality.

  3. Drought-induced xylem pit membrane damage in aspen and balsam poplar.

    PubMed

    Hillabrand, Rachel M; Hacke, Uwe G; Lieffers, Victor J

    2016-10-01

    Drought induces an increase in a tree's vulnerability to a loss of its hydraulic conductivity in many tree species, including two common in western Canada, trembling aspen (Populus tremuloides) and balsam poplar (Populus balsamifera). Termed 'cavitation fatigue' or 'air-seeding fatigue', the mechanism of this phenomenon is not well understood, but hypothesized to be a result of damage to xylem pit membranes. To examine the validity of this hypothesis, the effect of drought on the porosity of pit membranes in aspen and balsam poplar was investigated. Controlled drought and bench dehydration treatments were used to induce fatigue and scanning electron microscopy (SEM) was used to image pit membranes for relative porosity evaluations from air-dried samples after ethanol dehydration. A significant increase in the diameter of the largest pore was found in the drought and dehydration treatments of aspen, while an increase in the percentage of porous pit membranes was found in the dehydration treatments of both species. Additionally, the location of the largest pore per pit membrane was observed to tend toward the periphery of the membrane.

  4. The Oak Ridge Y-12 Plant biological monitoring and abatement program for East Fork Poplar Creek

    SciTech Connect

    Loar, J.M.; Adams, S.M.; Allison, L.J.; Giddings, J.M.; McCarthy, J.F.; Southworth, G.R.; Smith, J.G.; Stewart, A.J.; Springborn Bionomics, Inc., Wareham, MA; Oak Ridge National Lab., TN )

    1989-10-01

    In May 1985, a National Pollutant Discharge Elimination System permit was issued for the Oak Ridge Y-12 Plant, a nuclear weapons components production facility located in Oak Ridge, Tennessee, and operated by Martin Marietta Energy Systems, Inc., for the US Department of Energy. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Oak Ridge Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek), in particular, the growth and propagation of fish and aquatic life, as designated by the Tennessee Department of Health and Environment. A second purpose for the BMAP is to document the ecological effects resulting from implementation of a water pollution control program that will include construction of nine new wastewater treatment facilities over the next 4 years. Because of the complex nature of the effluent discharged to East Fork Poplar Creek and the temporal and spatial variability in the composition of the effluent (i.e., temporal variability related to various pollution abatement measures that will be implemented over the next several years and spatial variability caused by pollutant inputs downstream of the Oak Ridge Y-12 Plant), a comprehensive, integrated approach to biological monitoring was developed for the BMAP. 39 refs., 5 figs., 8 tabs.

  5. Bud set in poplar--genetic dissection of a complex trait in natural and hybrid populations.

    PubMed

    Rohde, Antje; Storme, Véronique; Jorge, Véronique; Gaudet, Muriel; Vitacolonna, Nicola; Fabbrini, Francesco; Ruttink, Tom; Zaina, Giusi; Marron, Nicolas; Dillen, Sophie; Steenackers, Marijke; Sabatti, Maurizio; Morgante, Michele; Boerjan, Wout; Bastien, Catherine

    2011-01-01

    • The seasonal timing of growth events is crucial to tree distribution and conservation. The seasonal growth cycle is strongly adapted to the local climate that is changing because of global warming. We studied bud set as one cornerstone of the seasonal growth cycle in an integrative approach. • Bud set was dissected at the phenotypic level into several components, and phenotypic components with most genetic variation were identified. While phenotypic variation resided in the timing of growth cessation, and even so more in the duration from growth cessation to bud set, the timing of growth cessation had a stronger genetic component in both natural and hybrid populations. • Quantitative trait loci (QTL) were identified for the most discriminative phenotypic bud-set components across four poplar pedigrees. The QTL from different pedigrees were recurrently detected in six regions of the poplar genome. • These regions of 1.83-4.25 Mbp in size, containing between 202 and 394 genes, form the basis for further molecular-genetic dissection of bud set.

  6. Stimulating natural defenses in poplar clones (OP-367) increases plant metabolism of carbon tetrachloride.

    PubMed

    Ferrieri, Abigail P; Thorpe, Michael R; Ferrieri, Richard A

    2006-01-01

    Groundwater contamination by carbon tetrachloride (CCl4) presents a health risk as a potential carcinogen and pollutant that is capable of depleting the ozone layer. Although use of poplar trees in a phytoremediation capacity has proven to be cost effective for cleaning contaminated sites, minimizing leaf emission of volatile contaminants remains a pressing issue. We hypothesized that recently fixed carbon plays a key role in CCl4 metabolism in planta yielding nonvolatile trichloroacetic acid (TCA) and that the extent of this metabolism can be altered by heightening plant defenses. Labeling intact leaves with (11)CO2 (t 1/2 20.4 m) can test this hypothesis, because the extremely short half-life of the tracer reflects only those processes involving recently fixed carbon. Using radio-HPLC analysis, we observed [(11)C]TCA from leaf extract from poplar clones (OP-367) whose roots were exposed to a saturated solution of CCl4 (520 ppm). Autoradiography of [(11)C]photosynthate showed increased leaf export and partitioning to the apex within 24 h of CCl4 exposure, suggesting that changes in plant metabolism and partitioning of recently fixed carbon occur rapidly. Additionally, leaf CCl4 emissions were highest in the morning, when carbon pools are low, suggesting a link between contaminant metabolism and leaf carbon utilization. Further, treatment with methyljasmonate, a plant hormone implicated in defense signal transduction, reduced leaf CCl4 emissions two-fold due to the increased formation of TCA.

  7. Herbivore-induced volatile emission in black poplar: regulation and role in attracting herbivore enemies.

    PubMed

    Clavijo McCormick, Andrea; Irmisch, Sandra; Reinecke, Andreas; Boeckler, G Andreas; Veit, Daniel; Reichelt, Michael; Hansson, Bill S; Gershenzon, Jonathan; Köllner, Tobias G; Unsicker, Sybille B

    2014-08-01

    After herbivory, plants release volatile organic compounds from damaged foliage as well as from nearby undamaged leaves that attract herbivore enemies. Little is known about what controls the volatile emission differences between damaged and undamaged tissues and how these affect the orientation of herbivore enemies. We investigated volatile emission from damaged and adjacent undamaged foliage of black poplar (Populus nigra) after herbivory by gypsy moth (Lymantria dispar) caterpillars and determined the compounds mediating the attraction of the gypsy moth parasitoid Glyptapanteles liparidis (Braconidae). Female parasitoids were more attracted to gypsy moth-damaged leaves than to adjacent non-damaged leaves. The most characteristic volatiles of damaged versus neighbouring undamaged leaves included terpenes, green leaf volatiles and nitrogen-containing compounds, such as aldoximes and nitriles. Electrophysiological recordings and olfactometer bioassays demonstrated the importance of nitrogenous volatiles. Under field conditions, parasitic Hymenoptera were more attracted to traps baited with these substances than most other compounds. The differences in volatile emission profiles between damaged and undamaged foliage appear to be regulated by jasmonate signalling and the local activation of volatile biosynthesis. We conclude that characteristic volatiles from damaged black poplar foliage are essential cues enabling parasitoids to find their hosts.

  8. Interaction of drought and ozone exposure on isoprene emission from extensively cultivated poplar.

    PubMed

    Yuan, Xiangyang; Calatayud, Vicent; Gao, Feng; Fares, Silvano; Paoletti, Elena; Tian, Yuan; Feng, Zhaozhong

    2016-10-01

    The combined effects of ozone (O3 ) and drought on isoprene emission were studied for the first time. Young hybrid poplars (clone 546, Populus deltoides cv. 55/56 x P. deltoides cv. Imperial) were exposed to O3 (charcoal-filtered air, CF, and non-filtered air +40 ppb, E-O3 ) and soil water stress (well-watered, WW, and mild drought, MD, one-third irrigation) for 96 days. Consistent with light-saturated photosynthesis (Asat ), intercellular CO2 concentration (Ci ) and chlorophyll content, isoprene emission depended on drought, O3 , leaf position and sampling time. Drought stimulated emission (+38.4%), and O3 decreased it (-40.4%). Ozone increased the carbon cost per unit of isoprene emission. Ozone and drought effects were stronger in middle leaves (13th-15th from the apex) than in upper leaves (6th-8th). Only Asat showed a significant interaction between O3 and drought. When the responses were up-scaled to the entire-plant level, however, drought effects on total leaf area translated into around twice higher emission from WW plants in clean air than in E-O3 . Our results suggest that direct effects on plant emission rates and changes in total leaf area may affect isoprene emission from intensively cultivated hybrid poplar under combined MD and O3 exposure, with important feedbacks for air quality. PMID:27411672

  9. Herbivore-induced volatile emission in black poplar: regulation and role in attracting herbivore enemies.

    PubMed

    Clavijo McCormick, Andrea; Irmisch, Sandra; Reinecke, Andreas; Boeckler, G Andreas; Veit, Daniel; Reichelt, Michael; Hansson, Bill S; Gershenzon, Jonathan; Köllner, Tobias G; Unsicker, Sybille B

    2014-08-01

    After herbivory, plants release volatile organic compounds from damaged foliage as well as from nearby undamaged leaves that attract herbivore enemies. Little is known about what controls the volatile emission differences between damaged and undamaged tissues and how these affect the orientation of herbivore enemies. We investigated volatile emission from damaged and adjacent undamaged foliage of black poplar (Populus nigra) after herbivory by gypsy moth (Lymantria dispar) caterpillars and determined the compounds mediating the attraction of the gypsy moth parasitoid Glyptapanteles liparidis (Braconidae). Female parasitoids were more attracted to gypsy moth-damaged leaves than to adjacent non-damaged leaves. The most characteristic volatiles of damaged versus neighbouring undamaged leaves included terpenes, green leaf volatiles and nitrogen-containing compounds, such as aldoximes and nitriles. Electrophysiological recordings and olfactometer bioassays demonstrated the importance of nitrogenous volatiles. Under field conditions, parasitic Hymenoptera were more attracted to traps baited with these substances than most other compounds. The differences in volatile emission profiles between damaged and undamaged foliage appear to be regulated by jasmonate signalling and the local activation of volatile biosynthesis. We conclude that characteristic volatiles from damaged black poplar foliage are essential cues enabling parasitoids to find their hosts. PMID:24471487

  10. A molecular timetable for apical bud formation and dormancy induction in poplar.

    PubMed

    Ruttink, Tom; Arend, Matthias; Morreel, Kris; Storme, Véronique; Rombauts, Stephane; Fromm, Jörg; Bhalerao, Rishikesh P; Boerjan, Wout; Rohde, Antje

    2007-08-01

    The growth of perennial plants in the temperate zone alternates with periods of dormancy that are typically initiated during bud development in autumn. In a systems biology approach to unravel the underlying molecular program of apical bud development in poplar (Populus tremula x Populus alba), combined transcript and metabolite profiling were applied to a high-resolution time course from short-day induction to complete dormancy. Metabolite and gene expression dynamics were used to reconstruct the temporal sequence of events during bud development. Importantly, bud development could be dissected into bud formation, acclimation to dehydration and cold, and dormancy. To each of these processes, specific sets of regulatory and marker genes and metabolites are associated and provide a reference frame for future functional studies. Light, ethylene, and abscisic acid signal transduction pathways consecutively control bud development by setting, modifying, or terminating these processes. Ethylene signal transduction is positioned temporally between light and abscisic acid signals and is putatively activated by transiently low hexose pools. The timing and place of cell proliferation arrest (related to dormancy) and of the accumulation of storage compounds (related to acclimation processes) were established within the bud by electron microscopy. Finally, the identification of a large set of genes commonly expressed during the growth-to-dormancy transitions in poplar apical buds, cambium, or Arabidopsis thaliana seeds suggests parallels in the underlying molecular mechanisms in different plant organs.

  11. Local selection across a latitudinal gradient shapes nucleotide diversity in balsam poplar, Populus balsamifera L.

    PubMed

    Keller, Stephen R; Levsen, Nicholas; Ingvarsson, Pär K; Olson, Matthew S; Tiffin, Peter

    2011-08-01

    Molecular studies of adaptive evolution often focus on detecting selective sweeps driven by positive selection on a species-wide scale; however, much adaptation is local, particularly of ecologically important traits. Here, we look for evidence of range-wide and local adaptation at candidate genes for adaptive phenology in balsam poplar, Populus balsamifera, a widespread forest tree whose range extends across environmental gradients of photoperiod and growing season length. We examined nucleotide diversity of 27 poplar homologs of the flowering-time network-a group of genes that control plant developmental phenology through interactions with environmental cues such as photoperiod and temperature. Only one gene, ZTL2, showed evidence of reduced diversity and an excess of fixed replacement sites, consistent with a species-wide selective sweep. Two other genes, LFY and FRI, harbored high levels of nucleotide diversity and exhibited elevated differentiation between northern and southern accessions, suggesting local adaptation along a latitudinal gradient. Interestingly, FRI has also been identified as a target of local selection between northern and southern accessions of Arabidopsis thaliana, indicating that this gene may be commonly involved in ecological adaptation in distantly related species. Our findings suggest an important role for local selection shaping molecular diversity and reveal limitations of inferring molecular adaptation from analyses designed only to detect species-wide selective sweeps.

  12. [Optimization model of spatial population structure: example of poplar moth laying eggs on leaves].

    PubMed

    Sekretenko, O P; Sukhovol'skiĭ, V G; Tarasova, O V

    2002-01-01

    The authors analyze spatial distribution and survival of populations of poplar moth Litchcolletis populifoliella Tr. on its feeding plant--balsam poplar Populus balsamifera. Imago of the moth glue its eggs on the leaves thus determining the future location of their offspring on the host plant. Spatial distribution of eggs on leaf surface and distribution of leaves according egg numbers are not random. On the short distance from each egg the average number of eggs is less, than it should be in case of random distribution. While this distance increases up to some particular value the occurrence of eggs is higher than random. Thus, the eggs of moth are located by groups on the leaf surface. Within each group eggs are situated not very close to each other, this allowing larvae to lower competition for common resource. It is suggested that on the same feeding plant individuals have different interactions: competition, caused by limited quantity of resource and cooperation that is necessary to resist leaf defensive (antibiosis) reaction.

  13. Genome-wide identification and in silico analysis of poplar peptide deformylases.

    PubMed

    Liu, Chang-Cai; Liu, Bao-Guang; Yang, Zhi-Wei; Li, Chun-Ming; Wang, Bai-Chen; Yang, Chuan-Ping

    2012-01-01

    Peptide deformylases (PDF) behave as monomeric metal cation hydrolases for the removal of the N-formyl group (Fo). This is an essential step in the N-terminal Met excision (NME) that occurs in these proteins from eukaryotic mitochondria or chloroplasts. Although PDFs have been identified and their structure and function have been characterized in several herbaceous species, it remains as yet unexplored in poplar. Here, we report on the first identification of two genes (PtrPDF1A and PtrPDF1B) respectively encoding two putative PDF polypeptides in Populus trichocarpa by genome-wide investigation. One of them (XP_002300047.1) encoded by PtrPDF1B (XM_002300011.1) was truncated, and then revised into a complete sequence based on its ESTs support with high confidence. We document that the two PDF1s of Populus are evolutionarily divergent, likely as a result of independent duplicated events. Furthermore, in silico simulations demonstrated that PtrPDF1A and PtrPDF1B should act as similar PDF catalytic activities to their corresponding PDF orthologs in Arabidopsis. This result would be value of for further assessment of their biological activities in poplar, and further experiments are now required to confirm them. PMID:22606033

  14. Physical and chemical characteristics of products from the torrefaction of yellow poplar (Liriodendron tulipifera).

    PubMed

    Kim, Young-Hun; Lee, Soo-Min; Lee, Hyoung-Woo; Lee, Jae-Won

    2012-07-01

    We investigated the characteristics of torrefied yellow poplar (Liriodendron tulipifera) depending on reaction time (30 min) and temperature (240-280 °C). The thermogravimetric, grindability and calorific value of torrefied biomass were analyzed. As the torrefaction temperature increased, the carbon content of torrefied biomass increased from 49.50% to 54.42%, while the hydrogen and oxygen contents decreased from 6.09% to 5.65% and 28.71% to 26.61%, respectively. The highest calorific value was 1233 kJ/kg when torrefaction was performed at 280 °C for 30 min. An overall increase in energy density and decrease in mass and energy yield was observed with the increase in torrefaction temperature. The analysis of thermal decomposition demonstrated that the hemicelluloses contained in torrefied biomass decreased with increasing torrefaction temperature, whereas cellulose and lignin were only slightly affected. The grindability of torrefied biomass was significantly improved when torrefaction was performed at high temperature. Torrefaction of yellow poplar improved the chemical and physical fuel properties of the biomass.

  15. An investigation of shallow ground-water quality near East Fork Poplar Creek, Oak Ridge, Tennessee

    USGS Publications Warehouse

    Carmichael, J.K.

    1989-01-01

    Alluvial soils of the flood plain of East Fork Poplar Creek in Oak Ridge, Tennessee, are contaminated with mercury and other metals, organic compounds, and radio-nuclides originating from the Y-12 Plant, a nuclear-processing facility located within the U.S. Department of Energy 's Oak Ridge Reservation. Observation wells were installed in the shallow aquifer of the flood plain, and water quality samples were collected to determine if contaminants are present in the shallow groundwater. Groundwater in the shallow aquifer occurs under water-table conditions. Recharge is primarily from precipitation and discharge is to East Fork Poplar Creek. Groundwater levels fluctuate seasonally in response to variations in recharge and evapotranspiration. During extremely dry periods, the water table drops below the base of the shallow aquifer in some flood-plain areas. Contaminants found in water samples from several of the wells in concentrations which equaled or exceeded drinking-water standards established by the U.S. Environmental Protection Agency are antimony, chromium, lead, mercury, selenium, phenols, and strontium-90. Total and dissolved uranium concentrations exceeded the analytical detection limit in nearly 70% of the wells in the flood plain. The results of water quality determinations demonstrate that elevated concentrations of most trace metals (and possibly organic compounds and radionuclides) were caused by contaminated sediments in the samples. The presence of contaminated sediment in samples is suspected to be the result of borehole contamination during well installation. (USGS)

  16. Tulip-poplar leaf diffusion resistance calculated from stomatal dimensions and varying environmental parameters

    SciTech Connect

    McConathy, R.K.

    1983-03-01

    The study describes the gradients of stomatal size and density in the crown of a mature forest-grown tulip-poplar (Liriodendron tulipifera L.) in eastern Tennessee. These data are used to predict leaf resistance to vapor diffusion in relation to stomatal width and boundary layer resistance. Stomatal density on individual leaves did not vary, but density increased with increasing crown height. Stomatal size decreased with increasing height of leaves within the crown. Stomatal size and density variations interacted to result in a constant number of stomata per leaf at all crown heights. Stomatal diffusive resistance values calculated from stomatal measurements and varying environmental parameters indicated that stomatal resistance controlled transpiration water losses only at small apertures (<0.6 ..mu..m). Boundary layer resistance was controlling at large stomatal apertures (>0.6 ..mu..m) and at low wind speeds (approx.100 cm/s). Under normal forest conditions tulip-poplar stomatal resistance exercised more control over transpiration than did boundary layer resistance.

  17. Anaerobic digestion of poplar processing residues for methane production after alkaline treatment.

    PubMed

    Yao, Yiqing; He, Mulan; Ren, Yubing; Ma, Liying; Luo, Yang; Sheng, Hongmei; Xiang, Yun; Zhang, Hua; Li, Qien; An, Lizhe

    2013-04-01

    Poplar processing residues were used for methane production by anaerobic digestion after alkaline treatment and methane production was measured. The highest methane production of 271.9 L/kg volatile solid (VS) was obtained at conditions of 35 g/L and 5.0% NaOH, which was 113.8% higher than non-alkaline treated samples, and 28.9% higher than that of corn straw, which is the conventional anaerobic digestion material in China. The maximal enhancement of 275.5% obtained at conditions of 50 g/L and 7.0% NaOH. Degradation of cellulose, hemicellulose and lignin after treatment increased by 4.0-9.0%, 3.3-6.2%, and 11.1-20.5%, respectively, with NaOH dose ranged from 3.0% to 7.0%. Scanning electron microscopy (SEM), FTIR spectra and Crystallinity measurements showed that the lignocellulosic structures were disrupted by NaOH. The results indicate poplar processing residues might be an efficient substrate for methane production after alkaline treatment.

  18. Horizontal gene transfer to endogenous endophytic bacteria from poplar improves phytoremediation of toluene.

    PubMed

    Taghavi, Safiyh; Barac, Tanja; Greenberg, Bill; Borremans, Brigitte; Vangronsveld, Jaco; van der Lelie, Daniel

    2005-12-01

    Poplar, a plant species frequently used for phytoremediation of groundwater contaminated with organic solvents, was inoculated with the endophyte Burkholderia cepacia VM1468. This strain, whose natural host is yellow lupine, contains