Change search
Refine search result
1 - 15 of 15
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1. Barraclough, Timothy G.
    et al.
    Humphreys, Aelys M.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Imperial College London, UK.
    The evolutionary reality of species and higher taxa in plants: a survey of post-modern opinion and evidence2015In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 207, no 2, 291-296 p.Article, review/survey (Refereed)
    Abstract [en]

    Species are normally considered to be the fundamental unit for understanding the evolution of biodiversity. Yet, in a survey of botanists in 1940, twice as many felt that plant genera were more natural units than plant species. Revisiting the survey, we found more people now regarded species as a more evolutionarily real unit, but a sizeable number still felt that genera were more evolutionarily real than species. Definitions of evolutionarily real' split into those based on shared evolutionary history and those based on shared evolutionary fate via ongoing evolutionary processes. We discuss recent work testing for shared evolutionary fate at the species and higher levels and present preliminary evidence for evolutionarily significant higher taxa in plants.

  • 2. Baskaran, Preetisri
    et al.
    Hyvönen, Riitta
    Berglund, S. Linnea
    Clemmensen, Karina E.
    Ågren, Göran I.
    Lindahl, Björn D.
    Manzoni, Stefano
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Modelling the influence of ectomycorrhizal decomposition on plant nutrition and soil carbon sequestration in boreal forest ecosystems2017In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 213, no 3, 1452-1465 p.Article in journal (Refereed)
    Abstract [en]

    Tree growth in boreal forests is limited by nitrogen (N) availability. Most boreal forest trees form symbiotic associations with ectomycorrhizal (ECM) fungi, which improve the uptake of inorganic N and also have the capacity to decompose soil organic matter (SOM) and to mobilize organic N (ECM decomposition'). To study the effects of ECM decomposition' on ecosystem carbon (C) and N balances, we performed a sensitivity analysis on a model of C and N flows between plants, SOM, saprotrophs, ECM fungi, and inorganic N stores. The analysis indicates that C and N balances were sensitive to model parameters regulating ECM biomass and decomposition. Under low N availability, the optimal C allocation to ECM fungi, above which the symbiosis switches from mutualism to parasitism, increases with increasing relative involvement of ECM fungi in SOM decomposition. Under low N conditions, increased ECM organic N mining promotes tree growth but decreases soil C storage, leading to a negative correlation between C stores above- and below-ground. The interplay between plant production and soil C storage is sensitive to the partitioning of decomposition between ECM fungi and saprotrophs. Better understanding of interactions between functional guilds of soil fungi may significantly improve predictions of ecosystem responses to environmental change.

  • 3. Bay, Guillaume
    et al.
    Nahar, Nurun
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Oubre, Matthieu
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Whitehouse, Martin J.
    Wardle, David A.
    Zackrisson, Olle
    Nilsson, Marie-Charlotte
    Rasmussen, Ulla
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Boreal feather mosses secrete chemical signals to gain nitrogen2013In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 200, no 1, 54-60 p.Article in journal (Refereed)
    Abstract [en]

    The mechanistic basis of feather moss-cyanobacteria associations, a main driver of nitrogen (N) input into boreal forests, remains unknown. Here, we studied colonization by Nostoc sp. on two feather mosses that form these associations (Pleurozium schreberi and Hylocomium splendens) and two acrocarpous mosses that do not (Dicranum polysetum and Polytrichum commune). We also determined how N availability and moss reproductive stage affects colonization, and measured N transfer from cyanobacteria to mosses. The ability of mosses to induce differentiation of cyanobacterial hormogonia, and of hormogonia to then colonize mosses and re-establish a functional symbiosis was determined through microcosm experiments, microscopy and acetylene reduction assays. Nitrogen transfer between cyanobacteria and Pleurozium schreberi was monitored by secondary ion mass spectrometry (SIMS). All mosses induced hormogonia differentiation but only feather mosses were subsequently colonized. Colonization on Pleurozium schreberi was enhanced during the moss reproductive phase but impaired by elevated N. Transfer of N from cyanobacteria to their host moss was observed. Our results reveal that feather mosses likely secrete species-specific chemo-attractants when N-limited, which guide cyanobacteria towards them and from which they gain N. We conclude that this signalling is regulated by N demands of mosses, and serves as a control of N input into boreal forests.

  • 4. De Frenne, Pieter
    et al.
    Coomes, David A.
    De Schrijver, An
    Staelens, Jeroen
    Alexander, Jake M.
    Bernhardt-Roemermann, Markus
    Brunet, Jorg
    Chabrerie, Olivier
    Chiarucci, Alessandro
    den Ouden, Jan
    Eckstein, R. Lutz
    Graae, Bente J.
    Gruwez, Robert
    Hedl, Radim
    Hermy, Martin
    Kolb, Annette
    Marell, Anders
    Mullender, Samantha M.
    Olsen, Siri L.
    Orczewska, Anna
    Peterken, George
    Petrik, Petr
    Plue, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Simonson, William D.
    Tomescu, Cezar V.
    Vangansbeke, Pieter
    Verstraeten, Gorik
    Vesterdal, Lars
    Wulf, Monika
    Verheyen, Kris
    Plant movements and climate warming: intraspecific variation in growth responses to nonlocal soils2014In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 202, no 2, 431-441 p.Article in journal (Refereed)
    Abstract [en]

    <list list-type=bulleted id=nph12672-list-0001> Most range shift predictions focus on the dispersal phase of the colonization process. Because moving populations experience increasingly dissimilar nonclimatic environmental conditions as they track climate warming, it is also critical to test how individuals originating from contrasting thermal environments can establish in nonlocal sites. We assess the intraspecific variation in growth responses to nonlocal soils by planting a widespread grass of deciduous forests (Milium effusum) into an experimental common garden using combinations of seeds and soil sampled in 22 sites across its distributional range, and reflecting movement scenarios of up to 1600km. Furthermore, to determine temperature and forest-structural effects, the plants and soils were experimentally warmed and shaded. We found significantly positive effects of the difference between the temperature of the sites of seed and soil collection on growth and seedling emergence rates. Migrant plants might thus encounter increasingly favourable soil conditions while tracking the isotherms towards currently colder' soils. These effects persisted under experimental warming. Rising temperatures and light availability generally enhanced plant performance. Our results suggest that abiotic and biotic soil characteristics can shape climate change-driven plant movements by affecting growth of nonlocal migrants, a mechanism which should be integrated into predictions of future range shifts.

  • 5. dos Reis, Fabio Bueno, Jr.
    et al.
    Simon, Marcelo F.
    Gross, Eduardo
    Boddey, Robert M.
    Elliott, Geoffrey N.
    Neto, Nicolau E.
    Loureiro, M. de Fatima
    de Queiroz, Luciano P.
    Scotti, Maria Rita
    Chen, Wen-Ming
    Norén, Agneta
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Rubio, Maria C.
    de Faria, Sergio M.
    Bontemps, Cyril
    Goi, Silvia R.
    Young, J. Peter W.
    Sprent, Janet I.
    James, Euan K.
    Nodulation and nitrogen fixation by Mimosa spp. in the Cerrado and Caatinga biomes of Brazil2010In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 186, no 4, 934-946 p.Article in journal (Refereed)
    Abstract [en]

    P>An extensive survey of nodulation in the legume genus Mimosa was undertaken in two major biomes in Brazil, the Cerrado and the Caatinga, in both of which there are high degrees of endemicity of the genus. Nodules were collected from 67 of the 70 Mimosa spp. found. Thirteen of the species were newly reported as nodulating. Nodules were examined by light and electron microscopy, and all except for M. gatesiae had a structure typical of effective Mimosa nodules. The endosymbiotic bacteria in nodules from all of the Mimosa spp. were identified as Burkholderia via immunolabelling with an antibody against Burkholderia phymatum STM815. Twenty of the 23 Mimosa nodules tested were shown to contain nitrogenase by immunolabelling with an antibody to the nitrogenase Fe- (nifH) protein, and using the delta 15N (15N natural abundance) technique, contributions by biological N-2 fixation of up to 60% of total plant N were calculated for Caatinga Mimosa spp. It is concluded that nodulation in Mimosa is a generic character, and that the preferred symbionts of Brazilian species are Burkholderia. This is the first study to demonstrate N-2 fixation by beta-rhizobial symbioses in the field.

  • 6.
    Humphreys, Aelys M.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Division of Biology, Imperial College London, Silwood Park Campus, Berkshire, UK.
    Linder, H. Peter
    Evidence for recent evolution of cold tolerance in grasses suggests current distribution is not limited by (low) temperature2013In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 198, no 4, 1261-1273 p.Article in journal (Refereed)
    Abstract [en]

    Temperature is considered an important determinant of biodiversity distribution patterns. Grasses (Poaceae) occupy among the warmest and coldest environments on earth but the role of cold tolerance evolution in generating this distribution is understudied. We studied cold tolerance of Danthonioideae (c. 280 species), a major constituent of the austral temperate grass flora. We determined differences in cold tolerance among species from different continents grown in a common winter garden and assessed the relationship between measured cold tolerance and that predicted by species ranges. We then used temperatures in current ranges and a phylogeny of 81% of the species to study the timing and mode of cold tolerance evolution across the subfamily. Species ranges generally underestimate cold tolerance but are still a meaningful representation of differences in cold tolerance among species. We infer cold tolerance evolution to have commenced at the onset of danthonioid diversification, subsequently increasing in both pace and extent in certain lineages. Interspecific variation in cold tolerance is better accounted for by spatial than phylogenetic distance. Contrary to expectations, temperature low temperature in particular appears not to limit the distribution of this temperate clade. Competition, time or dispersal limitation could explain its relative absence from northern temperate regions.

  • 7.
    Ininbergs, Karolina
    et al.
    Stockholm University, Faculty of Science, Department of Botany.
    Bay, Guillaume
    Stockholm University, Faculty of Science, Department of Botany.
    Rasmussen, Ulla
    Stockholm University, Faculty of Science, Department of Botany.
    Wardle, David A.
    Nilsson, Marie-Charlotte
    Composition and diversity of nifH genes of nitrogen-fixing cyanobacteria associated with boreal forest feather mosses2011In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 192, no 2, 507-517 p.Article in journal (Refereed)
    Abstract [en]

    Recent studies have revealed that nitrogen fixation by cyanobacteria living in association with feather mosses is a major input of nitrogen to boreal forests. We characterized the community composition and diversity of cyanobacterial nifH phylotypes associated with each of two feather moss species (Pleurozium schreberi and Hylocomium splendens) on each of 30 lake islands varying in ecosystem properties in northern Sweden. Nitrogen fixation was measured using acetylene reduction, and nifH sequences were amplified using general and cyanobacterial selective primers, separated and analyzed using density gradient gel electrophoresis (DGGE) or cloning, and further sequenced for phylogenetic analyses. Analyses of DGGE fingerprinting patterns revealed two host-specific clusters (one for each moss species), and sequence analysis showed five clusters of nifH phylotypes originating from heterocystous cyanobacteria. For H. splendens only, N(2) fixation was related to both nifH composition and diversity among islands. We demonstrated that the cyanobacterial communities associated with feather mosses show a high degree of host specificity. However, phylotype composition and diversity, and nitrogen fixation, did not differ among groups of islands that varied greatly in their availability of resources. These results suggest that moss species identity, but not extrinsic environmental conditions, serves as the primary determinant of nitrogen-fixing cyanobacterial communities that inhabit mosses.

  • 8.
    Laenen, Benjamin
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Stockholm University, Science for Life Laboratory (SciLifeLab). University of Liège, Belgium.
    Machac, Antonin
    Gradstein, S. Robbert
    Shaw, Blanka
    Patino, Jairo
    Desamore, Aurelie
    Goffinet, Bernard
    Cox, Cymon J.
    Shaw, A. Jonathan
    Vanderpoorten, Alain
    Increased diversification rates follow shifts to bisexuality in liverworts2016In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 210, no 3, 1121-1129 p.Article in journal (Refereed)
    Abstract [en]

    Shifts in sexual systems are one of the key drivers of species diversification. In contrast to angiosperms, unisexuality prevails in bryophytes. Here, we test the hypotheses that bisexuality evolved from an ancestral unisexual condition and is a key innovation in liverworts. We investigate whether shifts in sexual systems influence diversification using hidden state speciation and extinction analysis (HiSSE). This new method compares the effects of the variable of interest to the best-fitting latent variable, yielding robust and conservative tests. We find that the transitions in sexual systems are significantly biased toward unisexuality, even though bisexuality is coupled with increased diversification. Sexual systems are strongly conserved deep within the liverwort tree but become much more labile toward the present. Bisexuality appears to be a key innovation in liverworts. Its effects on diversification are presumably mediated by the interplay of high fertilization rates, massive spore production and long-distance dispersal, which may separately or together have facilitated liverwort speciation, suppressed their extinction, or both. Importantly, shifts in liverwort sexual systems have the opposite effect when compared to angiosperms, leading to contrasting diversification patterns between the two groups. The high prevalence of unisexuality among liverworts suggests, however, a strong selection for sexual dimorphism.

  • 9. Lindh, Magnus
    et al.
    Johansson, Jacob
    Bolmgren, Kjell
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Swedish University of Agricultural Sciences, Sweden.
    Lundström, Niklas L. P.
    Brannström, Ake
    Jonzén, Niclas
    Constrained growth flips the direction of optimal phenological responses among annual plants2016In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 209, no 4, 1591-1599 p.Article in journal (Refereed)
    Abstract [en]

    Phenological changes among plants due to climate change are well documented, but often hard to interpret. In order to assess the adaptive value of observed changes, we study how annual plants with and without growth constraints should optimize their flowering time when productivity and season length changes. We consider growth constraints that depend on the plant's vegetative mass: self-shading, costs for nonphotosynthetic structural tissue and sibling competition. We derive the optimal flowering time from a dynamic energy allocation model using optimal control theory. We prove that an immediate switch (bang-bang control) from vegetative to reproductive growth is optimal with constrained growth and constant mortality. Increasing mean productivity, while keeping season length constant and growth unconstrained, delayed the optimal flowering time. When growth was constrained and productivity was relatively high, the optimal flowering time advanced instead. When the growth season was extended equally at both ends, the optimal flowering time was advanced under constrained growth and delayed under unconstrained growth. Our results suggests that growth constraints are key factors to consider when interpreting phenological flowering responses. It can help to explain phenological patterns along productivity gradients, and links empirical observations made on calendar scales with life-history theory.

  • 10. Mursinoff, Sini
    et al.
    Tack, Ayco J. M.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Spatial variation in soil biota mediates plant adaptation to a foliar pathogen2017In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 214, no 2, 644-654 p.Article in journal (Refereed)
    Abstract [en]

    Theory suggests that below-ground spatial heterogeneity may mediate host-parasite evolutionary dynamics and patterns of local adaptation, but this has rarely been tested in natural systems. Here, we test experimentally for the impact of spatial variation in the abiotic and biotic soil environment on the evolutionary outcome of the interaction between the host plant Plantago lanceolata and its specialist foliar pathogen Podosphaera plantaginis. Plants showed no adaptation to the local soil environment in the absence of natural enemies. However, quantitative, but not qualitative, plant resistance against local pathogens was higher when plants were grown in their local field soil than when they were grown in nonlocal field soil. This pattern was robust when extending the spatial scale beyond a single region, but disappeared with soil sterilization, indicating that soil biota mediated plant adaptation. We conclude that below-ground biotic heterogeneity mediates above-ground patterns of plant adaptation, resulting in increased plant resistance when plants are grown in their local soil environment. From an applied perspective, our findings emphasize the importance of using locally selected seeds in restoration ecology and low-input agriculture.

  • 11. Partel, Meelis
    et al.
    Opik, Maarja
    Moora, Mari
    Tedersoo, Leho
    Szava-Kovats, Robert
    Rosendahl, Soren
    Rillig, Matthias C.
    Lekberg, Ylva
    Kreft, Holger
    Helgason, Thorunn
    Eriksson, Ove
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Davison, John
    de Bello, Francesco
    Caruso, Tancredi
    Zobel, Martin
    Historical biome distribution and recent human disturbance shape the diversity of arbuscular mycorrhizal fungi2017In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 216, no 1, 227-238 p.Article in journal (Refereed)
    Abstract [en]

    The availability of global microbial diversity data, collected using standardized metabarcoding techniques, makes microorganisms promising models for investigating the role of regional and local factors in driving biodiversity. Here we modelled the global diversity of symbiotic arbuscular mycorrhizal (AM) fungi using currently available data on AM fungal molecular diversity (small subunit (SSU) ribosomal RNA (rRNA) gene sequences) in field samples. To differentiate between regional and local effects, we estimated species pools (sets of potentially suitable taxa) for each site, which are expected to reflect regional processes. We then calculated community completeness, an index showing the fraction of the species pool present, which is expected to reflect local processes. We found significant spatial variation, globally in species pool size, as well as in local and dark diversity (absent members of the species pool). Species pool size was larger close to areas containing tropical grasslands during the last glacial maximum, which are possible centres of diversification. Community completeness was greater in regions of high wilderness (remoteness from human disturbance). Local diversity was correlated with wilderness and current connectivity to mountain grasslands. Applying the species pool concept to symbiotic fungi facilitated a better understanding of how biodiversity can be jointly shaped by large-scale historical processes and recent human disturbance.

  • 12.
    Pawlowski, Katharina
    et al.
    Stockholm University, Faculty of Science, Department of Botany.
    Zdyb, Anna
    Stockholm University, Faculty of Science, Department of Botany.
    Demchenko, Kirill
    Hause, Bettina
    Heumann, Jan
    Feussner, Ivo
    Grzeganek, Peter
    Göbel, Cornelia
    Mrosk, Cornelia
    Jasmonate biosynthesis in legume and actinorhizal nodules2011In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 189, no 2, 568-579 p.Article in journal (Refereed)
    Abstract [en]

    • Jasmonic acid (JA) is a plant signalling compound that has been implicated in theregulation of mutualistic symbioses. In order to understand the spatial distributionof JA biosynthetic capacity in nodules of two actinorhizal species, Casaurina glauca and Datisca glomerata, and one legume, Medicago truncatula, we determined thelocalization of allene oxide cyclase (AOC) which catalyses a committed step inJA biosynthesis. In all nodule types analysed, AOC was detected exclusively inuninfected cells.

    • The levels of JA were compared in the roots and nodules of the three plantspecies. The nodules and noninoculated roots of the two actinorhizal species, andthe root systems of M. truncatula, noninoculated or nodulated with wild-type Sinorhizobium meliloti or with mutants unable to fix nitrogen, did not showsignificant differences in JA levels. However, JA levels in all plant organs examined increased significantly on mechanical disturbance.

    • To study whether JA played a regulatory role in the nodules of M. truncatula, composite plants containing roots expressing an MtAOC1-sense or MtAOC1-RNAi construct were inoculated with S. meliloti. Neither an increase nor reductionin AOC levels resulted in altered nodule formation.

    • These data suggest that jasmonates are not involved in the development andfunction of root nodules.

  • 13.
    Tack, Ayco J. M.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. University of Helsinki, Finland.
    Laine, Anna-Liisa
    Burdon, Jeremy J.
    Bissett, Andrew
    Thrall, Peter H.
    Below-ground abiotic and biotic heterogeneity shapes above-ground infection outcomes and spatial divergence in a host-parasite interaction2015In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 207, no 4, 1159-1169 p.Article in journal (Refereed)
    Abstract [en]

    We investigated the impact of below-ground and above-ground environmental heterogeneity on the ecology and evolution of a natural plant-pathogen interaction. We combined field measurements and a reciprocal inoculation experiment to investigate the potential for natural variation in abiotic and biotic factors to mediate infection outcomes in the association between the fungal pathogen Melampsora lini and its wild flax host, Linum marginale, where pathogen strains and plant lines originated from two ecologically distinct habitat types that occur in close proximity (bog' and hill'). The two habitat types differed strikingly in soil moisture and soil microbiota. Infection outcomes for different host-pathogen combinations were strongly affected by the habitat of origin of the plant lines and pathogen strains, the soil environment and their interactions. Our results suggested that tradeoffs play a key role in explaining the evolutionary divergence in interaction traits among the two habitat types. Overall, we demonstrate that soil heterogeneity, by mediating infection outcomes and evolutionary divergence, can contribute to the maintenance of variation in resistance and pathogenicity within a natural host-pathogen metapopulation.

  • 14. Tzafestas, Kyriakos
    et al.
    Razalan, Maria M.
    Gyulev, Ivan
    Mazari, Aslam M. A.
    Stockholm University, Faculty of Science, Department of Neurochemistry.
    Mannervik, Bengt
    Stockholm University, Faculty of Science, Department of Neurochemistry.
    Rylott, Elizabeth L.
    Bruce, Neil C.
    Expression of a Drosophila glutathione transferase in Arabidopsis confers the ability to detoxify the environmental pollutant, and explosive, 2,4,6-trinitrotoluene2017In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 214, no 1, 294-303 p.Article in journal (Refereed)
    Abstract [en]

    The explosive 2,4,6-trinitrotoluene (TNT) is a significant, global environmental pollutant that is both toxic and recalcitrant to degradation. Given the sheer scale and inaccessible nature of contaminated areas, phytoremediation may be a viable clean-up approach. Here, we have characterized a Drosophila melanogaster glutathione transferase (DmGSTE6) which has activity towards TNT. Recombinantly expressed, purified DmGSTE6 produces predominantly 2-glutathionyl-4, 6-dinitrotoluene, and has a 2.5-fold higher Maximal Velocity (Vmax), and five-fold lower Michaelis Constant (Km) than previously characterized TNT-active Arabidopsis thaliana (Arabidopsis) GSTs. Expression of DmGSTE6 in Arabidopsis conferred enhanced resistance to TNT, and increased the ability to remove TNT from contaminated soil relative to wild-type plants. Arabidopsis lines overexpressing TNT-active GSTs AtGST-U24 and AtGST-U25 were compromised in biomass production when grown in the absence of TNT. This yield drag was not observed in the DmGSTE6-expressing Arabidopsis lines. We hypothesize that increased levels of endogenous TNT-active GSTs catalyse excessive glutathionylation of endogenous substrates, depleting glutathione pools, an activity that DmGST may lack. In conclusion, DmGSTE6 has activity towards TNT, producing a compound with potential for further biodegradation. Selecting or manipulating plants to confer DmGSTE6-like activity could contribute towards development of phytoremediation strategies to clean up TNT from polluted military sites.

  • 15. Vico, Giulia
    et al.
    Manzoni, Stefano
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Nkurunziza, Libere
    Murphy, Kevin
    Weih, Martin
    Trade-offs between seed output and life span - a quantitative comparison of traits between annual and perennial congeneric species2016In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 209, no 1, 104-114 p.Article in journal (Refereed)
    Abstract [en]

    Perennial plants allocate more resources belowground, thus sustaining important ecosystem services. Hence, shifting from annual to perennial crops has been advocated towards a more sustainable agriculture. Nevertheless, wild perennial species have lower seed production than selected annuals, raising the questions of whether there is a fundamental trade-off between reproductive effort and life span, and whether such trade-off can be overcome through selection. In order to address these questions and to isolate life span from phylogenetic and environmental factors, we conducted a meta-analysis encompassing c. 3000 congeneric annual/perennial pairs from 28 genera. This meta-analysis is complemented with a minimalist model of long-term productivity in perennial species. Perennials allocate more resources belowground and less to seeds than congeneric annuals, independently of selection history. However, existing perennial wheat and rice could achieve yields similar to annuals if they survived three years and each year doubled their biomass, as other perennial grasses do. Selected perennial crops maintain the large belowground allocation of wild perennials, and thus can provide desired regulatory ecosystem services. To match the seed yield of annuals, biomass production of perennial grains must be increased to amounts attained by some perennial grasses - if this goal can be met, perennial crops can provide a more sustainable alternative to annuals.

1 - 15 of 15
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf