Ecology and evolution of invasive maple tree species

Biological invasions represent a major driver of the current decline of biodiversity worldwide and generate expensive management programs. Increasing attention has thus been devoted to the study of invasive species, which in tum has shown to provide valuable insights on ecological and evolutionary processes regulating species coexistence. A proper test of mechanisms promoting invasions requires nonetheless the use of a biogeographical approach between species native and invasive ranges. This approach has rarely been applied, especially for tree invasions, and Acer negundo L. and Acer platanoides L., native to North America and Europe, respectively, and reciprocally introduced into the other's range where they have spread, offer a perfect opportunity to employ it. Based on various methods such as population demography contrasts, meta-analytical statistics and quantitative genetics, this· project sought to highlight specific environmental factors, species functional traits and evolutionary processes that drive the success of maple tree invasion. The two species currently exhibit different stages of invasion throughout the geographical areas studied. While A. negundo has already aggressively invaded riparian habitats of Southern France, A. platanoides is present but not yet dominant in deciduous forests of Southern Ontario, Canada. Invasive genotypes of A. negundo exhibited pre-adapted plasticity to non limiting resource conditions and genetic differentiation in growth, above-ground biomass and phenology relative to native conspecifics while life history traits were only environmentally controlled in A. platanoides. This discrepancy may also be explained by a combination of different disturbance regimes between invaded habitats and different life history strategy between species. Frequent disturbances in riparian forests have favored the establishment of the fast-growing and highly competitive A. negundo while less disturbed inland forests have impeded dominance by the shade tolerant and dispersal limited A. platanoides. Overall, this project successfully demonstrated the importance of using various methods at the biogeographical scale to identify the contribution of multiple factors in the success of invasive species. It also illustrates that invasive trees have the potential to rapidly adapt to novel conditions and therefore represent appropriate models to assess the migration rate of tree populations and the role of adaptive plasticity and natural selection in a climate warming context

Comparative Analysis of a Series of pH‐Responsive Sulphonated Europium Complexes for Bioassays Monitoring Acidification

The synthesis and photophysical evaluation of a series of hydrophilic sulphonated and pH responsive luminescent europium(III) probes are reported. The Eu emission intensities and lifetimes increase very significantly on lowering pH, leading to a ‘switching on’ of Eu luminescence in more acidic media. By varying the nature of the substituents at an integral aniline nitrogen atom located in the sensitising chromophore, the pKa value of the complex can be tuned to between 4.3 and 6.3 for a set of five Eu(III) complexes. These systems are designed to allow conjugation to targeting vectors permitting, for example, the monitoring of receptor internalisation in cells. This approach can be used to tag proteins selectively and allows the monitoring of uptake into acidic organelles, enabling the creation of time-resolved internalisation assays to follow pH change in real time, both in vitro and in cellulo

Leaf physiological and morphological constraints of water-use efficiency in C3_3 plants

The increasing evaporative demand due to climate change will significantly affect the balance of carbon assimilation and water losses of plants worldwide. The development of crop varieties with improved water-use efficiency (WUE) will be critical for adapting agricultural strategies under predicted future climates. This review aims to summarize the most important leaf morpho-physiological constraints of WUE in C3 plants and identify gaps in knowledge. From the carbon gain side of the WUE, the discussed parameters are mesophyll conductance, carboxylation efficiency and respiratory losses. The traits and parameters affecting the waterside of WUE balance discussed in this review are stomatal size and density, stomatal control and residual water losses (cuticular and bark conductance), nocturnal conductance and leaf hydraulic conductance. In addition, we discussed the impact of leaf anatomy and crown architecture on both the carbon gain and water loss components of WUE. There are multiple possible targets for future development in understanding sources of WUE variability in plants. We identified residual water losses and respiratory carbon losses as the greatest knowledge gaps of whole-plant WUE assessments. Moreover, the impact of trichomes, leaf hydraulic conductance and canopy structure on plants’ WUE is still not well understood. The development of a multi-trait approach is urgently needed for a better understanding of WUE dynamics and optimization

Invasive Acer negundo outperforms native species in non-limiting resource environments due to its higher phenotypic plasticity

<p>Abstract</p> <p>Background</p> <p>To identify the determinants of invasiveness, comparisons of traits of invasive and native species are commonly performed. Invasiveness is generally linked to higher values of reproductive, physiological and growth-related traits of the invasives relative to the natives in the introduced range. Phenotypic plasticity of these traits has also been cited to increase the success of invasive species but has been little studied in invasive tree species. In a greenhouse experiment, we compared ecophysiological traits between an invasive species to Europe, <it>Acer negundo</it>, and early- and late-successional co-occurring native species, under different light, nutrient availability and disturbance regimes. We also compared species of the same species groups <it>in </it><it>situ</it>, in riparian forests.</p> <p>Results</p> <p>Under non-limiting resources, <it>A. negundo </it>seedlings showed higher growth rates than the native species. However, <it>A. negundo </it>displayed equivalent or lower photosynthetic capacities and nitrogen content per unit leaf area compared to the native species; these findings were observed both on the seedlings in the greenhouse experiment and on adult trees <it>in situ</it>. These physiological traits were mostly conservative along the different light, nutrient and disturbance environments. Overall, under non-limiting light and nutrient conditions, specific leaf area and total leaf area of <it>A. negundo </it>were substantially larger. The invasive species presented a higher plasticity in allocation to foliage and therefore in growth with increasing nutrient and light availability relative to the native species.</p> <p>Conclusions</p> <p>The higher level of plasticity of the invasive species in foliage allocation in response to light and nutrient availability induced a better growth in non-limiting resource environments. These results give us more elements on the invasiveness of <it>A. negundo </it>and suggest that such behaviour could explain the ability of <it>A. negundo </it>to outperform native tree species, contributes to its spread in European resource-rich riparian forests and impedes its establishment under closed-canopy hardwood forests.</p

Dopamine interaction with a polyamine cryptand of 1H-pyrazole in the absence and in the presence of Cu(II) ions. Crystal structure of [Cu2(H21L](ClO4)3·2H2O

The crystal structure of the binuclear Cu2+ complex [Cu2(H21L)](ClO4)3·2H2O of the cryptand L = 1,4,7,8,11,14,17,20,21,24,29,32,33,36-tetradecaazapentacyclo[12.12.12.1^(6,9).1^(19,22),1,^31,34]hentetraconta-6,9(41),19(40), 21,31,34(39)-hexaene is presented; evidence for the formation in solution of binary L–dopamine and ternary Cu2+–L– dopamine complexes is presented.Escarti Alemany, Francisco, [email protected] ; Garcia-España Monsonis, Enrique, [email protected] ; Latorre Saborit, Julio, [email protected]

Cu2+-Induced formation of cage-like compounds containing pyrazole macrocycles

The crystal structure of the complex [Cu4(H22L)2(H2O)2- (ClO4)2](ClO4)2·2H2O where L is a new pyrazole ligand containing 1,5-diaminopentane spacers represents a new form of obtaining metal ion-induced inorganic–organic cages.Escarti Alemany, Francisco, [email protected] ; Latorre Saborit, Julio, [email protected] ; Garcia-España Monsonis, Enrique, [email protected]

The Role of Provenance for the Projected Growth of Juvenile European Beech under Climate Change

European beech is one of the most common tree species in Europe and is generally suggested to play even more of a prominent role in forestry in the future. It seems to have the potential to partially replace Norway spruce, as it is less sensitive to expected warmer and drier conditions. It is, however, not well known in which regions these new plantings would be particularly favourable and if specific provenances may be better adapted to the new conditions than others. Therefore, we estimated the potential early height growth under climate conditions in 2040–2060 for 20 beech provenances across a region covering the Czech Republic and Slovakia. This Central European region is expected to experience considerably drier and warmer conditions in the future. For this exercise, we implemented a new neural network model developed from height growth information obtained from the open-access BeechCOSTe52 database. The simulations are driven by past and future climate data obtained from the WorldClim database of historical climate data and future climate projections. Simulations revealed that provenances originating from drier regions performed on average significantly better than those from regions with good water supply. Moreover, provenances originating from drier regions had a particularly large advantage in the relatively arid regions of Central Czechia and Southern Slovakia. We can also confirm that all provenances showed a high phenotypic plasticity of height growth across the whole investigated region

In vitro and in vivo trypanosomicidal activity of pyrazole-containing macrocyclic and macrobicyclic polyamines: Their action on acute and chronic phases of chagas disease

The in vitro and in vivo anti-Trypanosoma cruzi activity of the pyrazole-containing macrobicyclic polyamine 1 and N-methyl- and N-benzyl-substituted monocyclic polyamines 2 and 3 was studied. Activity against both the acute and chronic phases of Chagas disease was considered. The compounds were more active against the parasite and less toxic against Vero cells than the reference drug benznidazole, but 1 and 2 were especially effective, where cryptand 1 was the most active, particularly in the chronic phase. The activity results found for these compounds were complemented and discussed by considering their inhibitory effect on the iron superoxide dismutase enzyme of the parasite, the nature of the metabolites excreted after treatment, and the ultrastructural alterations produced. A complementary histopathological analysis confirmed that the compounds tested were significantly less toxic to mammals than the reference drug and that 1 and 2 exhibited lower levels of damage than 3.The authors thank the MCINN Projects: Consolider Ingenio CSD2010-00065 and CTQ2009-14288-C04-01, the FEDER funds and Generalitat Valenciana PROMETEO 2011/008, the Santander-Universidad Complutense Research Program GR58/08-921371-891, and the Spanish MEC Project CGL2008-03687-E/BOS for financial support. J.P. thanks MCINN for a predoctoral fellowship

EuroTracker (R) dyes: design, synthesis, structure and photophysical properties of very bright europium complexes and their use in bioassays and cellular optical imaging

The development of the brightest luminescent europium(III) complexes is traced, including analysis of the C3-symmetric core complex based on a functionalized triazacyclononane and identification of the most suitable strongly absorbing chromophore. Strategies for the synthesis of the complexes, including enantiopure analogues, are outlined and opportunities for applications in time-resolved microscopy and spectral imaging emphasised. Practicable examples are introduced, including selective organelle staining for cellular optical imaging at 65 nm resolution and the development of new bioassays using time resolved FRET methods

Comparative analysis of conjugated alkynyl chromophore-triazacyclononane ligands for sensitized emission of europium and terbium

A series of europium and terbium complexes based on a functionalized triazacyclononane carboxylate or phosphinate macrocyclic ligand is described. The influence of the anionic group, that is, carboxylate, methylphosphinate, or phenylphosphinate, on the photophysical properties was studied and rationalized on the basis of DFT calculated structures. The nature, number, and position of electron-donating or electron-withdrawing aryl substituents were varied systematically within the same phenylethynyl scaffold in order to optimize the brightness of the corresponding europium complexes and investigate their two-photon absorption properties. Finally, the europium complexes were examined in cell-imaging applications, and selected terbium complexes were studied as potential oxygen sensors