SwePub
Sök i SwePub databas

  form:Ext_t

Träfflista för sökning "db:Swepub ;srt2:(2010-2011);lar1:(umu);lar1:(slu)"

form:Search_simp_t: db:Swepub > (2010-2011) > swepub_uni:Umu_t > swepub_uni:Slu_t

  • navigation:Result_t 1-10 navigation:of_t 128
hitlist:Modify_result_t
   
hitlist:Enumeration_thitlist:Reference_thitlist:Reference_picture_thitlist:Find_Mark_t
1.
  • Abreu, Ilka, et al. (creator_code:aut_t)
  • UHPLC-ESI/TOFMS Determination of Salicylate-like Phenolic Gycosides in Populus tremula Leaves
  • 2011
  • record:In_t: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 0098-0331 .- 1573-1561. ; 37:8, s. 857-70
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • Associations of salicylate-like phenolic glycosides (PGs) with biological activity have been reported in Salix and Populus trees, but only for a few compounds, and in relation to a limited number of herbivores. By considering the full diversity of PGs, we may improve our ability to recognize genotypes or chemotype groups and enhance our understanding of their ecological function. Here, we present a fast and efficient general method for salicylate determination in leaves of Eurasian aspen that uses ultra-high performance liquid chromatography-electrospray ionization/time-of-flight mass spectrometry (UHPLC-ESI/TOFMS). The time required for the liquid chromatography separations was 13.5 min per sample, compared to around 60 min per sample for most HPLC protocols. In leaf samples from identical P. tremula genotypes with diverse propagation and treatment histories, we identified nine PGs. We found the compound-specific mass chromatograms to be more informative than the UV-visible chromatograms for compound identification and when quantitating samples with large variability in PG content. Signature compounds previously reported for P. tremoloides (tremulacin, tremuloidin, salicin, and salicortin) always were present, and five PGs (2'-O-cinnamoyl-salicortin, 2'-O-acetyl-salicortin, 2'-O-acetyl-salicin, acetyl-tremulacin, and salicyloyl-salicin) were detected for the first time in P. tremula. By using information about the formic acid adduct that appeared for PGs in the LTQ-Orbitrap MS environment, novel compounds like acetyl-tremulacin could be tentatively identified without the use of standards. The novel PGs were consistently either present in genotypes regardless of propagation and damage treatment or were not detectable. In some genotypes, concentrations of 2'-O-acetyl-salicortin and 2'-O-cinnamoyl-salicortin were similar to levels of biologically active PGs in other Salicaceous trees. Our study suggests that we may expect a wide variation in PG content in aspen populations which is of interest both for studies of interactions with herbivores and for mapping population structure.
  •  
2.
  • Albrectsen, Benedicte R., 1960-, et al. (creator_code:aut_t)
  • Endophytic fungi in European aspen (Populus tremula) leaves - diversity, detection, and a suggested correlation with herbivory resistance
  • 2010
  • record:In_t: Fungal diversity. - : Springer Science and Business Media LLC. - 1560-2745 .- 1878-9129. ; 41:1, s. 17-28
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • According to the geographic mosaic theory of coevolution (GMTC), clines of traits reflecting local co-adaptation (including resistance genes) should be common between a host and its parasite and should persist across time. To test the GMTC-assumption of persistent clinal patterns we compared the natural prevalence of two parasites on aspen Populus tremula trees: mining moths of the genus Phyllocnistis and leaf rust Melampsora spp. Damage data were collated from the Swedish National Forest Damage Inventory (2004–2006). In addition, occurrence of the parasites was scored in field conditions in two common gardens in the north and south of Sweden over five growing seasons (2004–2008), then related to biomass (stem height and diameter) and to concentrations of eleven leaf phenolics. Phyllocnistis mainly occurred in the northern garden, a distribution range which was confirmed by the countrywide inventory, although Phyllocnistis was more abundant on southern clones, providing evidence for possible local maladaptation. Melampsora occurred all over the country and in both gardens, but built up more quickly on northern clones, which suggests a centre of local clone maladaptation in the north. Stem growth also followed a clinal pattern as did the concentration of three phenolic compounds: benzoic acid, catechin and cinnamic acid. However, only benzoic acid was related to parasite presence: negatively to Phyllocnistis and positively to Melampsora and it could thus be a potential trait under selection. In conclusion, clines of Phyllocnistis were stronger and more persistent compared to Melampsora, which showed contrasting clines of varying strength. Our data thus support the assumption of the GMTC model that clines exist in the border between hot and cold spots and that they may be less persistent for parasites with an elevated gene flow, and/or for parasites which cover relatively larger hot spots surrounded by fewer cold spots.
  •  
3.
  • Albrectsen, Benedicte R, 1960-, et al. (creator_code:aut_t)
  • Large scale geographic clines of parasite damage to Populus tremula L
  • 2010
  • record:In_t: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 33:3, s. 483-493
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • In conclusion, clines of Phyllocnistis were stronger and more persistent compared to Melampsora, which showed contrasting clines of varying strength. Our data thus support the assumption of the GMTC model that clines exist in the border between hot and cold spots and that they may be less persistent for parasites with an elevated gene flow, and/or for parasites which cover relatively larger hot spots surrounded by fewer cold spots.
  •  
4.
  •  
5.
  • Axelsson, Petter, et al. (creator_code:aut_t)
  • Can leaf litter from genetically modified trees affect aquatic ecosystems?
  • 2010
  • record:In_t: Ecosystems (New York. Print). - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 13:7, s. 1049-1059
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • In addition to potential benefits, biotechnology in silviculture may also be associated with environmental considerations, including effects on organisms associated with the living tree and on ecosystems and processes dependent on tree residue. We examined whether genetic modification of lignin characteristics (CAD and COMT) in Populus sp. affected leaf litter quality, the decomposition of leaf litter, and the assemblages of aquatic insects colonizing the litter in three natural streams. The decomposition of leaf litter from one of the genetically modified (GM) lines (CAD) was affected in ways that were comparable over streams and harvest dates. After 84 days in streams, CAD-litter had lost approximately 6.1% less mass than the non-GM litter. Genetic modification also affected the concentration of phenolics and carbon in the litter but this only partially explained the decomposition differences, suggesting that other factors were also involved. Insect community analyses comparing GM and non-GM litter showed no significant differences, and the two GM litters showed differences only in the 84-day litterbags. The total abundance and species richness of insects were also similar on GM and non-GM litter. The results presented here suggest that genetic modifications in trees can influence litter quality and thus have a potential to generate effects that can cross ecosystem boundaries and influence ecosystem processes not directly associated with the tree. Overall, the realized ecological effects of the GM tree varieties used here were nevertheless shown to be relatively small.
  •  
6.
  • Axelsson, Petter, et al. (creator_code:aut_t)
  • Leaf litter from insect-resistant transgenic trees causes changes in aquatic insect community composition
  • 2011
  • record:In_t: Journal of Applied Ecology. - Malden : Wiley-Blackwell. - 0021-8901 .- 1365-2664. ; 48:6, s. 1472-1479
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • 1. Recent research has addressed how transgenic residues fromarable crops may influence adjacent waterways, aquatic consumers and important ecosystem processes such as litter breakdown rates. With future applications of transgenic plants in forestry, such concerns may apply to forest stream ecosystems. Before any large-scale release of genetically modified (GM) trees, it is therefore imperative to evaluate the effects of genetic modifications in trees on such ecosystems. 2. We conducted decomposition experiments under natural stream conditions using leaf litter from greenhouse grown GM trees (Populus tremula x Populus tremuloides) that express Bacillus thuringiensis (Bt) toxins (cry3Aa; targeting coleopteran leaf-feeding beetles) to examine the hypothesis that GM trees would affect litter decomposition rates and/or the aquatic arthropod community that colonizes and feeds on leaf litter in streams. 3. We show that two independent transformations of isogenic Populus trees to express Bt toxins caused similar changes to the composition of aquatic insects colonizing the leaf litter, ultimately manifested in a 25% and 33% increases in average insect abundance. 4. Measurements of 24 phenolic compounds as well as nitrogen (N) and carbon (C) in the litter did not significantly differ among modified and wild-type trees and were thus not sufficient to explain these differences in the insect assemblage. 5. Decomposition rates were comparable among litter treatments suggesting that the normal suite of leaf traits influencing decomposition was similar among litter treatments and that the shredding functions of the community were maintained despite the changes in insect community composition. 6. Synthesis and applications. We report that leaf litter from GM trees affected the composition of aquatic insect communities that colonized litter under natural stream conditions. This suggests that forest management using GM trees may affect adjacent waterways in unanticipated ways, which should be considered in future commercial applications of GM trees. We also argue that studies at different scales (e.g. species, communities and ecosystems) will be needed for a full understanding of the environmental effects of Bt plants.
  •  
7.
  • Axelsson, Petter, et al. (creator_code:aut_t)
  • Leaf ontogeny interacts with Bt modification to affect innate resistance in GM aspens
  • 2011
  • record:In_t: Chemoecology. - : Springer Science and Business Media LLC. - 0937-7409 .- 1423-0445. ; 21:3, s. 161-169
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • Bioassays with a non-target slug (Deroceras spp.) and chemical analyses were conducted using leaf tissue from already existing genetically modified insect-resistant aspen trees to examine whether genetic modifications to produce Bacillus thuringiensis (Bt) toxins could affect plant phytochemistry, which in turn might influence plant-herbivore interactions. Three major patterns emerged. First, two independent modifications for Bt resistance affected the phytochemical profiles of leaves such that both were different from the isogenic wild-type (Wt) control leaves, but also different from each other. Among the contributors to these differences are substances with a presumed involvement in resistance, such as salicortin and soluble condensed tannins. Second, bioassays with one Bt line suggest that the modification somehow affected innate resistance ("Innate" is used here in opposition to the "acquired" Bt resistance) in ways such that slugs preferred Bt over Wt leaves. Third, the preference test suggests that the innate resistance in Bt relative to Wt plants may not be uniformly expressed throughout the whole plant and that leaf ontogeny interacts with the modification to affect resistance. This was manifested through an ontogenetic determined increase in leaf consumption that was more than four times higher in Bt compared to Wt leaves. Our result are of principal importance, as these indicate that genetic modifications can affect innate resistance and thus non-target herbivores in ways that may have commercial and/or environmental consequences. The finding of a modification-ontogeny interaction effect on innate resistance may be especially important in assessments of GM plants with a long lifespan such as trees.
  •  
8.
  • Baba, Kyoko, et al. (creator_code:aut_t)
  • Activity-dormancy transition in the cambial meristem involves stage-specific modulation of auxin response in hybrid aspen.
  • 2011
  • record:In_t: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 108:8, s. 3418-23
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • The molecular basis of short-day-induced growth cessation and dormancy in the meristems of perennial plants (e.g., forest trees growing in temperate and high-latitude regions) is poorly understood. Using global transcript profiling, we show distinct stage-specific alterations in auxin responsiveness of the transcriptome in the stem tissues during short-day-induced growth cessation and both the transition to and establishment of dormancy in the cambial meristem of hybrid aspen trees. This stage-specific modulation of auxin signaling appears to be controlled via distinct mechanisms. Whereas the induction of growth cessation in the cambium could involve induction of repressor auxin response factors (ARFs) and down-regulation of activator ARFs, dormancy is associated with perturbation of the activity of the SKP-Cullin-F-box(TIR) (SCF(TIR)) complex, leading to potential stabilization of repressor auxin (AUX)/indole-3-acetic acid (IAA) proteins. Although the role of hormones, such as abscisic acid (ABA) and gibberellic acid (GA), in growth cessation and dormancy is well established, our data now implicate auxin in this process. Importantly, in contrast to most developmental processes in which regulation by auxin involves changes in cellular auxin contents, day-length-regulated induction of cambial growth cessation and dormancy involves changes in auxin responses rather than auxin content.
  •  
9.
  •  
10.
  • Belyaev, Yuri K (creator_code:aut_t)
  • Assessing accuracy of statistical inferences by resamplings
  • 2010
  • record:In_t: Mathematical and Statistical Models and Methods in Reliability. - New York : Birkhäuser Verlag. - 9780817649708 - 9780817649715 ; , s. 193-206
  • swepub:Mat_conferencepaper_t (swepub:level_scientificother_t)abstract
    • Suppose that a list of explanatory variables and corresponding random responses was obtained during a series of regression experiments. The characteristic of interest is the mean value of responses considered as a regression function of corresponding values of explanatory variables. For example, if responses are failure times of tested elements, then the conditional mean value of life time given the value of explanatory variable is one of the important reliability characteristics of the tested elements. The analysis of this type of data can be realized in the framework of linear heteroscedastic regression models. Here, one of the central problems is a consistent estimation of the unknown regression function when the size of data grows unboundedly. The problems related to analysis of regression data attracted many researches, see Wu [Ann. Statist. 14, 1261–1350 (1986)]. We give an approach to consistent solution of the problems under the assumption that values of explanatory variables are real numbers and the regression function is a polynomial with unknown degree and coefficients. The selection of regression function is based on resamplings from terms in the sum of the residuals estimated by the ordinary least squares method with various values of polynomial degree. In a similar way, resamplings from the weighted estimated residuals are used for consistent estimation of the deviations distributions of estimated coefficients from their true unknown values. The consistency of applied resamplings methods holds under certain assumptions, e.g. it is assumed that the residuals distributions have uniformly integrable second moments (assumption AW 2). Given in Appendix a variant of the Central Limit Resampling Theorem is used in the proofs of Theorems 1 and 2.
  •  
Skapa referenser, mejla, bekava och länka
  • navigation:Result_t 1-10 navigation:of_t 128
swepub:Mat_t
swepub:mat_article_t (106)
swepub:mat_report_t (7)
swepub:mat_chapter_t (6)
swepub:mat_conferencepaper_t (5)
swepub:mat_researchreview_t (3)
swepub:mat_book_t (1)
deldatabas:search_more_t
deldatabas:search_less_t
swepub:Level_t
swepub:level_refereed_t (112)
swepub:level_scientificother_t (15)
swepub:level_popularscientific_t (1)
swepub:Hitlist_author_t
Moritz, Thomas (9)
Hjältén, Joakim (7)
Laudon, Hjalmar (6)
Moen, Jon (6)
Wiberg, Karin (5)
Nilsson, Mats (4)
deldatabas:search_more_t
Albrectsen, Benedict ... (4)
Jansson, Stina (3)
Bishop, Kevin (3)
Brännlund, Runar, 19 ... (3)
Witzell, Johanna (3)
Vrede, Tobias (3)
Persson, Lennart (3)
Nilsson, Ove (3)
Surowiec, Izabella (3)
Esseen, Per-Anders (3)
Lundgren, Tommy, 197 ... (3)
Bhalerao, Rishikesh ... (3)
Trygg, Johan (2)
Ottosson Löfvenius, ... (2)
Johansson, Annika (2)
Benlloch, Reyes (2)
Zheng, Bo (2)
Ljung, Karin (2)
Tysklind, Mats (2)
Athanassiadis, Dimit ... (2)
Jansson, Stefan, 195 ... (2)
Nordin, Annika (2)
Sandberg, Göran (2)
Elmberg, Johan (2)
Geladi, Paul (2)
Ericsson, Göran (2)
Köhler, Stephan (2)
Ohlsson, Anders (2)
Bergström, Ann-krist ... (2)
Bellini, Catherine (2)
Lundmark, Tomas (2)
Linder, Sune (2)
Giesler, Reiner (2)
Ågren, Anneli (2)
Sandström, Per (2)
Svensson, Johan (2)
Johansson, Mikael (2)
Reese, Heather (2)
Norrgren, Leif (2)
Lundgren, Tommy (2)
Wang, Xiao-Ru (2)
Keskitalo, E. Carina ... (2)
Lindgren, Dag (2)
Byström, Pär (2)
deldatabas:search_less_t
swepub:Hitlist_uni_t
hitlist:Language_t
language:Eng_t (123)
language:Swe_t (5)
hitlist:HSV_t
hsv:Cat_1_t (56)
hsv:Cat_4_t (28)
hsv:Cat_5_t (17)
hsv:Cat_3_t (5)
hsv:Cat_2_t (1)
hsv:Cat_6_t (1)

hitlist:Year_t

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt tools:Close_t

tools:Permalink_label_t