TY - JOUR A1 - Schwarzer, Christian A1 - Huamani, Fatima Cßceres A1 - Cano, Asunción A1 - La Torre, María I. La A1 - Weigend, Maximilian T1 - 400 years for long-distance dispersal and divergence in the northern atacama desert : insights from the Huaynaputina pumice slopes of Moquegua, Peru N2 - The Huaynaputina eruption (1600 AD, Moquegua, S Peru) in the northern Atacama Desert denuded the Ornate area of all vegetation and deposited deep pumice layers. Data on the flora, climate and soil characteristics of these slopes near Ornate at 1600-2600 m a.s.l. are provided. Fifty-nine angiosperm species established themselves on the pumice slopes in the past ca. 400 years, with the bulk of the small and herbaceous species and several species new records for Peru. Three Ornate sites were sampled in both a dry and a wet year and species numbers differed widely (14 versus 45 spp.). Among areas compared floristic composition is most similar to the Lomas de Tacna, and has less in common with geographically closer Lomas or Sierra formations. Nine species represent highly disjunct populations (200->700 km) from their nearest known living populations in central Peru, Chile, or Argentina/Bolivia and appear to have reached the area via long-distance dispersal. Abiotic conditions may have played an important role in limiting the establishment of species from the neighboring vegetation. Four taxa on the pumice slopes show clear morphological differences to populations elsewhere, two of them may represent neoendemics of the Ornate pumice, indicating rapid morphological divergence. (C) 2010 Elsevier Ltd. All rights reserved. Y1 - 2010 U6 - https://doi.org/10.1016/j.jaridenv.2010.05.034 SN - 0140-1963 ER - TY - JOUR A1 - Balazadeh, Salma A1 - Siddiqui, Hamad A1 - Allu, Annapurna Devi A1 - Matallana-Ramirez, Lilian Paola A1 - Caldana, Camila A1 - Mehrnia, Mohammad A1 - Zanor, Maria-Inés A1 - Koehler, Barbara A1 - Müller-Röber, Bernd T1 - A gene regulatory network controlled by the NAC transcription factor ANAC092/AtNAC2/ORE1 during salt-promoted senescence N2 - P>The onset and progression of senescence are under genetic and environmental control. The Arabidopsis thaliana NAC transcription factor ANAC092 (also called AtNAC2 and ORE1) has recently been shown to control age-dependent senescence, but its mode of action has not been analysed yet. To explore the regulatory network administered by ANAC092 we performed microarray-based expression profiling using estradiol-inducible ANAC092 overexpression lines. Approximately 46% of the 170 genes up-regulated upon ANAC092 induction are known senescence-associated genes, suggesting that the NAC factor exerts its role in senescence through a regulatory network that includes many of the genes previously reported to be senescence regulated. We selected 39 candidate genes and confirmed their time-dependent response to enhanced ANAC092 expression by quantitative RT-PCR. We also found that the majority of them (24 genes) are up-regulated by salt stress, a major promoter of plant senescence, in a manner similar to that of ANAC092, which itself is salt responsive. Furthermore, 24 genes like ANAC092 turned out to be stage-dependently expressed during seed growth with low expression at early and elevated expression at late stages of seed development. Disruption of ANAC092 increased the rate of seed germination under saline conditions, whereas the opposite occurred in respective overexpression plants. We also detected a delay of salinity-induced chlorophyll loss in detached anac092-1 mutant leaves. Promoter-reporter (GUS) studies revealed transcriptional control of ANAC092 expression during leaf and flower ageing and in response to salt stress. We conclude that ANAC092 exerts its functions during senescence and seed germination through partly overlapping target gene sets. Y1 - 2010 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0960-7412 U6 - https://doi.org/10.1111/j.1365-313X.2010.04151.x SN - 0960-7412 ER - TY - JOUR A1 - Dortay, Hakan A1 - Müller-Röber, Bernd T1 - A highly efficient pipeline for protein expression in Leishmania tarentolae using infrared fluorescence protein as marker N2 - Background: Leishmania tarentolae, a unicellular eukaryotic protozoan, has been established as a novel host for recombinant protein production in recent years. Current protocols for protein expression in Leishmania are, however, time consuming and require extensive lab work in order to identify well-expressing cell lines. Here we established an alternative protein expression work-flow that employs recently engineered infrared fluorescence protein (IFP) as a suitable and easy-to-handle reporter protein for recombinant protein expression in Leishmania. As model proteins we tested three proteins from the plant Arabidopsis thaliana, including a NAC and a type-B ARR transcription factor. Results: IFP and IFP fusion proteins were expressed in Leishmania and rapidly detected in cells by deconvolution microscopy and in culture by infrared imaging of 96-well microtiter plates using small cell culture volumes (2 mu L Y1 - 2010 UR - http://www.microbialcellfactories.com/home/ U6 - https://doi.org/10.1186/1475-2859-9-29 SN - 1475-2859 ER - TY - JOUR A1 - Sellrie, Frank A1 - Beck, Michael A1 - Hildebrandt, Niko A1 - Micheel, Burkhard T1 - A homogeneous time-resolved fluoroimmunoassay (TR-FIA) using antibody mediated luminescence quenching N2 - The determination of low-molecular weight substances (haptens) is demonstrated with a homogeneous time-resolved immunoassay using antibody-induced luminescence quenching. Our novel assay technology uses the newly developed monoclonal antibody (G24-BA9) to quench the luminescence of europium trisbipyridine (EuTBP). We performed a competitive biotin immunoassay including an EuTBP-biotin conjugate, the anti-EuTBP antibody G24-BA9 and streptavidin as assay components. Steric hindrance allows only the binding of either G24-BA9 (to the EuTBP moiety) or streptavidin (to the biotin moiety) to the EuTBP-biotin conjugate. Addition of the analyte biotin resulted in the binding of streptavidin to biotin and a concomitant preferred binding of G24-BA9 to EuTBP-biotin. Since G24-BA9 quenches the luminescence of EuTBP within the conjugate, the luminescence signal could be used to indicate and quantify the presence of free biotin in the system. All experiments were carried out in solution in the presence of 5% serum demonstrating the possibility of using our novel assay for a very fast determination of low molecular weight substances in biological fluids. Y1 - 2010 UR - http://www.rsc.org/Publishing/Journals/AY/Index.asp U6 - https://doi.org/10.1039/C0ay00306a SN - 1759-9660 ER - TY - JOUR A1 - Schmidtke, Andrea A1 - Gaedke, Ursula A1 - Weithoff, Guntram T1 - A mechanistic basis for underyielding in phytoplankton communities N2 - Species richness has been shown to increase biomass production of plant communities. Such overyielding occurs when a community performs better than its component monocultures due to the complementarity or dominance effect and is mostly detected in substrate-bound plant communities (terrestrial plants or submerged macrophytes) where resource use complementarity can be enhanced due to differences in rooting architecture and depth. Here, we investigated whether these findings arc generalizeable for free-floating phytoplankton with little potential for spatial differences in resource use. We performed aquatic microcosm experiments with eight phytoplankton species belonging to four functional groups to determine the manner in which species and community biovolume varies in relation to the number of functional groups and hypothesized that an increasing number of functional groups within a community promotes overyielding. Unexpectedly, we did not detect overyielding in any algal community. Instead. total community biovolume tended to decrease with all increasing, number of functional groups. This underyielding was mainly caused by the negative dominance effect that originated from a trade-off between growth rate and filial biovolume. In monoculture, slow-groing species built up higher biovolumes that fast-growing ones, whereas in mixture a fast-growing but low-productive species monopolized most of the nutrients and prevented competing species from developing high biovolumes expected from monocultures. Our results indicated that the Magnitude of the community biovolume was largely determined by the identify of one species. Functional diversity and resource use complementarity were of minor Importance among free-floating phytoplankton, possibly reflecting the lack of spatially heterogeneous resource distribution. As a consequence, biodiversity-ecosystem functioning relationships may not be easily generalizeable from substrate-bound plant to phytoplankton communities and vice versa. Y1 - 2010 UR - http://www.esajournals.org/doi/full/10.1890/08-2370.1 SN - 0012-9658 ER - TY - JOUR A1 - Van Kleunen, Mark A1 - Weber, Ewald A1 - Fischer, Markus T1 - A meta-analysis of trait differences between invasive and non-invasive plant species N2 - A major aim in ecology is identifying determinants of invasiveness. We performed a meta-analysis of 117 field or experimental-garden studies that measured pair-wise trait differences of a total of 125 invasive and 196 non-invasive plant species in the invasive range of the invasive species. We tested whether invasiveness is associated with performance-related traits (physiology, leaf-area allocation, shoot allocation, growth rate, size and fitness), and whether such associations depend on type of study and on biogeographical or biological factors. Overall, invasive species had significantly higher values than non-invasive species for all six trait categories. More trait differences were significant for invasive vs. native comparisons than for invasive vs. non-invasive alien comparisons. Moreover, for comparisons between invasive species and native species that themselves are invasive elsewhere, no trait differences were significant. Differences in physiology and growth rate were larger in tropical regions than in temperate regions. Trait differences did not depend on whether the invasive alien species originates from Europe, nor did they depend on the test environment. We conclude that invasive alien species had higher values for those traits related to performance than non-invasive species. This suggests that it might become possible to predict future plant invasions from species traits. Y1 - 2010 UR - http://www3.interscience.wiley.com/journal/118545752/home SN - 1461-023X ER - TY - JOUR A1 - Garcia-Mata, Carlos A1 - Wang, Jianwen A1 - Gajdanowicz, Pawel A1 - Gonzalez, Wendy A1 - Hills, Adrian A1 - Donald, Naomi A1 - Riedelsberger, Janin A1 - Amtmann, Anna A1 - Dreyer, Ingo A1 - Blatt, Michael R. T1 - A minimal cysteine motif required to activate the SKOR K+ channel of Arabidopsis by the reactive oxygen species H2O2 N2 - Reactive oxygen species (ROS) are essential for development and stress signaling in plants. They contribute to plant defense against pathogens, regulate stomatal transpiration, and influence nutrient uptake and partitioning. Although both Ca2+ and K+ channels of plants are known to be affected, virtually nothing is known of the targets for ROS at a molecular level. Here we report that a single cysteine (Cys) residue within the Kv-like SKOR K+ channel of Arabidopsis thaliana is essential for channel sensitivity to the ROS H2O2. We show that H2O2 rapidly enhanced current amplitude and activation kinetics of heterologously expressed SKOR, and the effects were reversed by the reducing agent dithiothreitol (DTT). Both H2O2 and DTT were active at the outer face of the membrane and current enhancement was strongly dependent on membrane depolarization, consistent with a H2O2-sensitive site on the SKOR protein that is exposed to the outside when the channel is in the open conformation. Cys substitutions identified a single residue, Cys(168) located within the S3 alpha-helix of the voltage sensor complex, to be essential for sensitivity to H2O2. The same Cys residue was a primary determinant for current block by covalent Cys S-methioylation with aqueous methanethiosulfonates. These, and additional data identify Cys168 as a critical target for H2O2, and implicate ROS-mediated control of the K+ channel in regulating mineral nutrient partitioning within the plant. Y1 - 2010 UR - http://www.jbc.org/ U6 - https://doi.org/10.1074/jbc.M110.141176 SN - 0021-9258 ER - TY - JOUR A1 - Shirzadian-Khorramabad, Reza A1 - Jing, Hai-Chun A1 - Everts, Gerja E. A1 - Schippers, Jos H. M. A1 - Hille, Jacques A1 - Dijkwel, Paul P. T1 - A mutation in the cytosolic O-acetylserine (thiol) lyase induces a genome-dependent early leaf death phenotype in Arabidopsis N2 - Background: Cysteine is a component in organic compounds including glutathione that have been implicated in the adaptation of plants to stresses. O-acetylserine (thiol) lyase (OAS-TL) catalyses the final step of cysteine biosynthesis. OAS-TL enzyme isoforms are localised in the cytoplasm, the plastids and mitochondria but the contribution of individual OAS-TL isoforms to plant sulphur metabolism has not yet been fully clarified. Results: The seedling lethal phenotype of the Arabidopsis onset of leaf death3-1 (old3-1) mutant is due to a point mutation in the OAS-A1 gene, encoding the cytosolic OAS-TL. The mutation causes a single amino acid substitution from Gly(162) to Glu(162), abolishing old3-1 OAS-TL activity in vitro. The old3-1 mutation segregates as a monogenic semidominant trait when backcrossed to its wild type accession Landsberg erecta (Ler-0) and the Di-2 accession. Consistent with its semi- dominant behaviour, wild type Ler-0 plants transformed with the mutated old3-1 gene, displayed the early leaf death phenotype. However, the old3-1 mutation segregates in an 11: 4: 1 (wild type: semi-dominant: mutant) ratio when backcrossed to the Colombia-0 and Wassilewskija accessions. Thus, the early leaf death phenotype depends on two semi- dominant loci. The second locus that determines the old3-1 early leaf death phenotype is referred to as odd-ler (for old3 determinant in the Ler accession) and is located on chromosome 3. The early leaf death phenotype is temperature dependent and is associated with increased expression of defence-response and oxidative-stress marker genes. Independent of the presence of the odd-ler gene, OAS-A1 is involved in maintaining sulphur and thiol levels and is required for resistance against cadmium stress. Conclusions: The cytosolic OAS-TL is involved in maintaining organic sulphur levels. The old3-1 mutation causes genome-dependent and independent phenotypes and uncovers a novel function for the mutated OAS- TL in cell death regulation. Y1 - 2010 UR - http://www.biomedcentral.com/1471-2229/ U6 - https://doi.org/10.1186/1471-2229-10-80 SN - 1471-2229 ER - TY - JOUR A1 - Hemp, Claudia A1 - Heller, Klaus-Gerhard A1 - Warchalowska-Sliwa, Elzbieta A1 - Hemp, Andreas T1 - A new genus and species of African Phaneropterinae (Orthoptera: Tettigoniidae), with data on its ecology, bioacoustics and chromosomes N2 - A new genus is proposed for a new East African Phaneropterinae species, Lunidia viridis, occurring on Mt. Kilimanjaro, Tanzania. Based on 33 records, notes on distribution and habitat are given, as well as acoustical data provided. Climate and vegetation parameters obtained along several transects on Mt. Kilimanjaro were evaluated describing the ecological niche of the new species. This interdisciplinary approach allows not only a profound characterisation of the ecological demands of the new genus but also predictions of the potential distribution area, which is tested for the first time for an African bush cricket species. Lunidia viridis n. gen. n. sp. occurs within humid and perhumid forests and Chagga home gardens, avoiding subhumid conditions on the mountain. It is found from 1,330 m upwards on the southern slopes, whereas the same ecological conditions are expressed from 1,930 m upwards on the drier northern slopes. Lunidia viridis has an unusually complex and variable song, which is described from field and laboratory recordings. The FISH technique for characterizing chromosomes is applied for the first time for an African species; L. viridis exhibits a karyotype typical for most Tettigoniidae. Y1 - 2010 UR - http://www.springerlink.com/content/1439-6092 U6 - https://doi.org/10.1007/s13127-010-0013-3 SN - 1439-6092 ER - TY - JOUR A1 - Hemp, Claudia A1 - Voje, Kjetil Lysne A1 - Heller, Klaus-Gerhard A1 - Warchalowska-Sliwa, Elzbieta A1 - Hemp, Andreas T1 - A new genus of African Acrometopini (Tettigoniidae: Phaneropterinae) based on morphology, chromosomes, acoustics, distribution, and molecular data, and the description of a new species N2 - A new genus, Altihoratosphaga, is erected for species formerly assigned to Horatosphaga Schaum, 1853, and a new species is described. Four species are included in Altihoratosphaga: Altihoratosphaga nomima (Karsch, 1896), Altihoratosphaga montivaga (Sjostedt, 1909), Altihoratosphaga nou (Hemp, 2007) and Altihoratosphaga hanangensis sp. nov. All four species are restricted to Tanzanian localities, and, except for A. nomima, for which no ecological data are available, are confined to montane forest habitats. Data on ecology, acoustics, chromosomes, and molecular relationships are provided, as well as a key to Altihoratosphaga species. The present-day distribution of Altihoratosphaga species suggests former migration events at times when wetter and colder climatic fluctuations favoured connections between montane forest communities, which today are isolated, enabling flightless taxa such as Altihoratosphaga and Monticolaria to spread. Y1 - 2010 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0024-4082 U6 - https://doi.org/10.1111/j.1096-3642.2009.00542.x SN - 0024-4082 ER -