TY - JOUR A1 - Tomiolo, Sara A1 - Metz, Johannes A1 - Blackwood, Christopher B. A1 - Djendouci, Karin A1 - Henneberg, Lorenz A1 - Mueller, Caroline A1 - Tielboerger, Katja T1 - Short-term drought and long-term climate legacy affect production of chemical defenses among plant ecotypes JF - Environmental and Experimental Botany N2 - Long and short-term climatic variation affect the ability of plants to simultaneously cope with increasing abiotic stress and biotic interactions. Specifically, ecotypes adapted to different climatic conditions (i.e., long-term legacy) may have to adjust their allocation to chemical defenses against enemies under acute drought (i.e., short-term response). Although several studies have addressed drought effects on chemical defense production, little is known about their intraspecific variation along resource gradients. Studying intraspecific variation is important for understanding how different environments select for defense strategies and how these may be affected directly and indirectly by changing climatic conditions. We conducted greenhouse experiments with the annual Biscutella didyma (Brassicaceae) to test the effects of long-term climatic legacy versus short-term drought stress on the concentrations of defense compounds (glucosinolates). To this aim, four ecotypes originating from a steep aridity gradient were exposed to contrasting water treatments. Concentrations of chemical defenses were measured separately in leaves of young (8 weeks) and old (14 weeks) plants, respectively. For young plants, ecotypes from the wettest climate (long-term legacy) as well as plants receiving high water treatments (short-term response) were better defended. A marginally significant interaction suggested that wetter ecotypes experienced a larger shift in defense production across water treatments. Older plants contained much lower glucosinolate concentrations and showed no differences between ecotypes and water treatments. Our results indicate that younger plants invest more resources into chemical defenses, possibly due to higher vulnerability to tissue loss compared to older plants. We propose that the strong response of wet ecotypes to water availability may be explained by a less pronounced adaptation to drought. KW - Plant chemical defense KW - Glucosinolates KW - Climatic legacy KW - Short-term drought KW - Brassicaceae KW - Gradients Y1 - 2017 U6 - https://doi.org/10.1016/j.envexpbot.2017.07.009 SN - 0098-8472 SN - 1873-7307 VL - 141 SP - 124 EP - 131 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Wurzbacher, Christian A1 - Fuchs, Andrea A1 - Attermeyer, Katrin A1 - Frindte, Katharina A1 - Grossart, Hans-Peter A1 - Hupfer, Michael A1 - Casper, Peter A1 - Monaghan, Michael T. T1 - Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment JF - Microbiome N2 - Background: Lake sediments harbor diverse microbial communities that cycle carbon and nutrients while being constantly colonized and potentially buried by organic matter sinking from the water column. The interaction of activity and burial remained largely unexplored in aquatic sediments. We aimed to relate taxonomic composition to sediment biogeochemical parameters, test whether community turnover with depth resulted from taxonomic replacement or from richness effects, and to provide a basic model for the vertical community structure in sediments. Methods: We analyzed four replicate sediment cores taken from 30-m depth in oligo-mesotrophic Lake Stechlin in northern Germany. Each 30-cm core spanned ca. 170 years of sediment accumulation according to Cs-137 dating and was sectioned into layers 1-4 cm thick. We examined a full suite of biogeochemical parameters and used DNA metabarcoding to examine community composition of microbial Archaea, Bacteria, and Eukaryota. Results: Community beta-diversity indicated nearly complete turnover within the uppermost 30 cm. We observed a pronounced shift from Eukaryota- and Bacteria-dominated upper layers (<5 cm) to Bacteria-dominated intermediate layers (5-14 cm) and to deep layers (>14 cm) dominated by enigmatic Archaea that typically occur in deep-sea sediments. Taxonomic replacement was the prevalent mechanism in structuring the community composition and was linked to parameters indicative of microbial activity (e.g., CO2 and CH4 concentration, bacterial protein production). Richness loss played a lesser role but was linked to conservative parameters (e.g., C, N, P) indicative of past conditions. Conclusions: By including all three domains, we were able to directly link the exponential decay of eukaryotes with the active sediment microbial community. The dominance of Archaea in deeper layers confirms earlier findings from marine systems and establishes freshwater sediments as a potential low-energy environment, similar to deep sea sediments. We propose a general model of sediment structure and function based on microbial characteristics and burial processes. An upper "replacement horizon" is dominated by rapid taxonomic turnover with depth, high microbial activity, and biotic interactions. A lower "depauperate horizon" is characterized by low taxonomic richness, more stable "low-energy" conditions, and a dominance of enigmatic Archaea. KW - Archaea KW - Eukaryota KW - Bacteria KW - Community KW - Freshwater KW - Lake KW - DNA metabarcoding KW - Beta-diversity KW - Sediment KW - Turnover Y1 - 2017 U6 - https://doi.org/10.1186/s40168-017-0255-9 SN - 2049-2618 VL - 5 PB - BioMed Central CY - London ER - TY - JOUR A1 - Leimkühler, Silke A1 - Bühning, Martin A1 - Beilschmidt, Lena T1 - Shared sulfur mobilization routes for tRNA thiolation and molybdenum cofactor biosynthesis in prokaryotes and eukaryotes JF - Biomolecules N2 - Modifications of transfer RNA (tRNA) have been shown to play critical roles in the biogenesis, metabolism, structural stability and function of RNA molecules, and the specific modifications of nucleobases with sulfur atoms in tRNA are present in pro- and eukaryotes. Here, especially the thiomodifications xm(5)s(2)U at the wobble position 34 in tRNAs for Lys, Gln and Glu, were suggested to have an important role during the translation process by ensuring accurate deciphering of the genetic code and by stabilization of the tRNA structure. The trafficking and delivery of sulfur nucleosides is a complex process carried out by sulfur relay systems involving numerous proteins, which not only deliver sulfur to the specific tRNAs but also to other sulfur-containing molecules including iron-sulfur clusters, thiamin, biotin, lipoic acid and molybdopterin (MPT). Among the biosynthesis of these sulfur-containing molecules, the biosynthesis of the molybdenum cofactor (Moco) and the synthesis of thio-modified tRNAs in particular show a surprising link by sharing protein components for sulfur mobilization in pro- and eukaryotes. KW - tRNA KW - molybdenum cofactor KW - persulfide KW - thiocarboxylate KW - thionucleosides KW - sulfurtransferase KW - l-cysteine desulfurase Y1 - 2017 U6 - https://doi.org/10.3390/biom7010005 SN - 2218-273X VL - 7 IS - 1 PB - MDPI CY - Basel ER - TY - GEN A1 - Kramer, Elena M. A1 - Lenhard, Michael T1 - Shape and form in plant development T2 - Seminars in cell & developmental biology Y1 - 2017 U6 - https://doi.org/10.1016/j.semcdb.2017.11.004 SN - 1084-9521 VL - 79 SP - 1 EP - 2 PB - Elsevier CY - London ER - TY - JOUR A1 - Zimmermann, Heike Hildegard A1 - Raschke, Elena A1 - Epp, Laura Saskia A1 - Stoof-Leichsenring, Kathleen Rosemarie A1 - Schwamborn, Georg A1 - Schirrmeister, Lutz A1 - Overduin, Pier Paul A1 - Herzschuh, Ulrike T1 - Sedimentary ancient DNA and pollen reveal the composition of plant organic matter in Late Quaternary permafrost sediments of the Buor Khaya Peninsula (north-eastern Siberia) JF - Biogeosciences N2 - Organic matter deposited in ancient, ice-rich permafrost sediments is vulnerable to climate change and may contribute to the future release of greenhouse gases; it is thus important to get a better characterization of the plant organic matter within such sediments. From a Late Quaternary permafrost sediment core from the Buor Khaya Peninsula, we analysed plant-derived sedimentary ancient DNA (sedaDNA) to identify the taxonomic composition of plant organic matter, and undertook palynological analysis to assess the environmental conditions during deposition. Using sedaDNA, we identified 154 taxa and from pollen and non-pollen palynomorphs we identified 83 taxa. In the deposits dated between 54 and 51 kyr BP, sedaDNA records a diverse low-centred polygon plant community including recurring aquatic pond vegetation while from the pollen record we infer terrestrial open-land vegetation with relatively dry environmental conditions at a regional scale. A fluctuating dominance of either terrestrial or swamp and aquatic taxa in both proxies allowed the local hydrological development of the polygon to be traced. In deposits dated between 11.4 and 9.7 kyr BP (13.4-11.1 cal kyr BP), sedaDNA shows a taxonomic turnover to moist shrub tundra and a lower taxonomic richness compared to the older samples. Pollen also records a shrub tundra community, mostly seen as changes in relative proportions of the most dominant taxa, while a decrease in taxonomic richness was less pronounced compared to sedaDNA. Our results show the advantages of using sedaDNA in combination with palynological analyses when macrofossils are rarely preserved. The high resolution of the sedaDNA record provides a detailed picture of the taxonomic composition of plant-derived organic matter throughout the core, and palynological analyses prove valuable by allowing for inferences of regional environmental conditions. Y1 - 2017 U6 - https://doi.org/10.5194/bg-14-575-2017 SN - 1726-4170 SN - 1726-4189 VL - 14 IS - 3 SP - 575 EP - 596 PB - Copernicus CY - Göttingen ER - TY - GEN A1 - Scheffler, Tatjana T1 - Root infinitives on Twitter T2 - Snippets Y1 - 2017 U6 - https://doi.org/10.7358/snip-2017-031-sche SN - 1590-1807 IS - 31 SP - 24 EP - 25 PB - Editioni Università di Lettere Economica Diritto CY - Milano ER - TY - JOUR A1 - Hasan, Ahmed Abdallah Abdalrahman Mohamed A1 - Hocher, Berthold T1 - Role of soluble and membrane-bound dipeptidyl peptidase-4 in diabetic nephropathy JF - Journal of Molecular Endocrinology N2 - Diabetic nephropathy is one of the most frequent, devastating and costly complications of diabetes. The available therapeutic approaches are limited. Dipeptidyl peptidase type 4 (DPP-4) inhibitors represent a new class of glucose-lowering drugs that might also have reno-protective properties. DPP-4 exists in two forms: a plasma membranebound form and a soluble form, and can exert many biological actions mainly through its peptidase activity and interaction with extracellular matrix components. The kidneys have the highest DPP-4 expression level in mammalians. DPP-4 expression and urinary activity are up-regulated in diabetic nephropathy, highlighting its role as a potential target to manage diabetic nephropathy. Preclinical animal studies and some clinical data suggest that DPP-4 inhibitors decrease the progression of diabetic nephropathy in a blood pressure-and glucose-independent manner. Many studies reported that these reno-protective effects could be due to increased half-life of DPP-4 substrates such as glucagon-like peptide-1 (GLP-1) and stromal derived factor-1 alpha (SDF-1a). However, the underlying mechanisms are far from being completely understood and clearly need further investigations. KW - DPP-4 KW - diabetic nephropathy KW - DPP-4 inhibitors KW - GLP-1 and SDF-1a Y1 - 2017 U6 - https://doi.org/10.1530/JME-17-0005 SN - 0952-5041 SN - 1479-6813 VL - 59 SP - R1 EP - R10 PB - Bioscientifica LTD CY - Bristol ER - TY - JOUR A1 - Ehmann, Lisa A1 - Zoller, Michael A1 - Minichmayr, Iris K. A1 - Scharf, Christina A1 - Maier, Barbara A1 - Schmitt, Maximilian V. A1 - Hartung, Niklas A1 - Huisinga, Wilhelm A1 - Vogeser, Michael A1 - Frey, Lorenz A1 - Zander, Johannes A1 - Kloft, Charlotte T1 - Role of renal function in risk assessment of target non-attainment after standard dosing of meropenem in critically ill patients BT - a prospective observational study JF - Critical care N2 - Background: Severe bacterial infections remain a major challenge in intensive care units because of their high prevalence and mortality. Adequate antibiotic exposure has been associated with clinical success in critically ill patients. The objective of this study was to investigate the target attainment of standard meropenem dosing in a heterogeneous critically ill population, to quantify the impact of the full renal function spectrum on meropenem exposure and target attainment, and ultimately to translate the findings into a tool for practical application. Methods: A prospective observational single-centre study was performed with critically ill patients with severe infections receiving standard dosing of meropenem. Serial blood samples were drawn over 4 study days to determine meropenem serum concentrations. Renal function was assessed by creatinine clearance according to the Cockcroft and Gault equation (CLCRCG). Variability in meropenem serum concentrations was quantified at the middle and end of each monitored dosing interval. The attainment of two pharmacokinetic/pharmacodynamic targets (100% T->MIC, 50% T->4xMIC) was evaluated for minimum inhibitory concentration (MIC) values of 2 mg/L and 8 mg/L and standard meropenem dosing (1000 mg, 30-minute infusion, every 8 h). Furthermore, we assessed the impact of CLCRCG on meropenem concentrations and target attainment and developed a tool for risk assessment of target non-attainment. Results: Large inter-and intra-patient variability in meropenem concentrations was observed in the critically ill population (n = 48). Attainment of the target 100% T->MIC was merely 48.4% and 20.6%, given MIC values of 2 mg/L and 8 mg/L, respectively, and similar for the target 50% T->4xMIC. A hyperbolic relationship between CLCRCG (25-255 ml/minute) and meropenem serum concentrations at the end of the dosing interval (C-8h) was derived. For infections with pathogens of MIC 2 mg/L, mild renal impairment up to augmented renal function was identified as a risk factor for target non-attainment (for MIC 8 mg/L, additionally, moderate renal impairment). Conclusions: The investigated standard meropenem dosing regimen appeared to result in insufficient meropenem exposure in a considerable fraction of critically ill patients. An easy-and free-to-use tool (the MeroRisk Calculator) for assessing the risk of target non-attainment for a given renal function and MIC value was developed. KW - beta-Lactam KW - Intensive care KW - Pharmacokinetics/Pharmacodynamics KW - Target attainment KW - Renal function KW - Risk assessment tool KW - Continuous renal replacement therapy Y1 - 2017 U6 - https://doi.org/10.1186/s13054-017-1829-4 SN - 1466-609X SN - 1364-8535 VL - 21 PB - BioMed Central CY - London ER - TY - JOUR A1 - Muñoz, Alfonso A1 - Mangano, Silvina A1 - Paz Gonzalez-Garcia, Mary A1 - Contreras, Ramon A1 - Sauer, Michael A1 - De Rybel, Bert A1 - Weijers, Dolf A1 - Juan Sanchez-Serrano, Jose A1 - Sanmartin, Maite A1 - Rojo, Enrique T1 - RIMA-Dependent Nuclear Accumulation of IYO Triggers Auxin-Irreversible Cell Differentiation in Arabidopsis JF - The plant cell N2 - The transcriptional regulator MINIYO (IYO) is essential and rate-limiting for initiating cell differentiation in Arabidopsis thaliana. Moreover, IYO moves from the cytosol into the nucleus in cells at the meristem periphery, possibly triggering their differentiation. However, the genetic mechanisms controlling IYO nuclear accumulation were unknown, and the evidence that increased nuclear IYO levels trigger differentiation remained correlative. Searching for IYO interactors, we identified RPAP2 IYO Mate (RIMA), a homolog of yeast and human proteins linked to nuclear import of selective cargo. Knockdown of RIMA causes delayed onset of cell differentiation, phenocopying the effects of IYO knockdown at the transcriptomic and developmental levels. Moreover, differentiation is completely blocked when IYO and RIMA activities are simultaneously reduced and is synergistically accelerated when IYO and RIMA are concurrently overexpressed, confirming their functional interaction. Indeed, RIMA knockdown reduces the nuclear levels of IYO and prevents its prodifferentiation activity, supporting the conclusion that RIMA-dependent nuclear IYO accumulation triggers cell differentiation in Arabidopsis. Importantly, by analyzing the effect of the IYO/RIMA pathway on xylem pole pericycle cells, we provide compelling evidence reinforcing the view that the capacity for de novo organogenesis and regeneration from mature plant tissues can reside in stem cell reservoirs. Y1 - 0201 U6 - https://doi.org/10.1105/tpc.16.00791 SN - 1040-4651 SN - 1532-298X VL - 29 IS - 3 SP - 575 EP - 588 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Yang, Xiaoping A1 - Darko, Kwame Oteng A1 - Huang, Yanjun A1 - He, Caimei A1 - Yang, Huansheng A1 - He, Shanping A1 - Li, Jianzhong A1 - Li, Jian A1 - Hocher, Berthold A1 - Yin, Yulong T1 - Resistant starch regulates gut microbiota BT - structure, biochemistry and cell signalling JF - Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology N2 - Starch is one of the most popular nutritional sources for both human and animals. Due to the variation of its nutritional traits and biochemical specificities, starch has been classified into rapidly digestible, slowly digestible and resistant starch. Resistant starch has its own unique chemical structure, and various forms of resistant starch are commercially available. It has been found being a multiple-functional regulator for treating metabolic dysfunction. Different functions of resistant starch such as modulation of the gut microbiota, gut peptides, circulating growth factors, circulating inflammatory mediators have been characterized by animal studies and clinical trials. In this mini-review, recent remarkable progress in resistant starch on gut microbiota, particularly the effect of structure, biochemistry and cell signaling on nutrition has been summarized, with highlights on its regulatory effect on gut microbiota. KW - Resistant starch KW - Gut microbiota KW - Nutrition Y1 - 2017 U6 - https://doi.org/10.1159/000477386 SN - 1015-8987 SN - 1421-9778 VL - 42 IS - 1 SP - 306 EP - 318 PB - Karger CY - Basel ER -