A Microbial Link between Elevated CO2 and Methane Emissions that is Plant Species-Specific

Rising atmospheric CO₂ levels alter the physiology of many plant species, but little is known of changes to root dynamics that may impact soil microbial mediation of greenhouse gas emissions from wetlands. We grew co-occurring wetland plant species that included an invasive reed canary grass (Phalaris arundinacea L.) and a native woolgrass (Scirpus cyperinus L.) in a controlled greenhouse facility under ambient (380 ppm) and elevated atmospheric CO₂ (700 ppm). We hypothesized that elevated atmospheric CO₂ would increase the abundance of both archaeal methanogen and bacterial methanotroph populations through stimulation of plant root and shoot biomass. We found that methane levels emitted from S. cyperinus shoots increased 1.5-fold under elevated CO₂, while no changes in methane levels were detected from P. arundincea. The increase in methane emissions was not explained by enhanced root or shoot growth of S. cyperinus. Principal components analysis of the total phospholipid fatty acid (PLFA) recovered from microbial cell membranes revealed that elevated CO₂ levels shifted the composition of the microbial community under S. cyperinus, while no changes were detected under P. arundinacea. More detailed analysis of microbial abundance showed no impact of elevated CO₂ on a fatty acid indicative of methanotrophic bacteria (18:2ω6c), and no changes were detected in the terminal restriction fragment length polymorphism (T-RFLP) relative abundance profiles of acetate-utilizing archaeal methanogens. Plant carbon depleted in ¹³C was traced into the PLFAs of soil microorganisms as a measure of the plant contribution to microbial PLFA. The relative contribution of plant-derived carbon to PLFA carbon was larger in S. cyperinus compared with P. arundinacea in four PLFAs (i14:0, i15:0, a15:0, and 18:1ω9t). The δ¹³C isotopic values indicate that the contribution of plant-derived carbon to microbial lipids could differ in rhizospheres of CO₂-responsive plant species, such as S. cyperinus in this study. The results from this study show that the CO₂–methane link found in S. cyperinus can occur without a corresponding change in methanogen and methanotroph relative abundances, but PLFA analysis indicated shifts in the community profile of bacteria and fungi that were unique to rhizospheres under elevated CO₂.     

The impact of nandrolone decanoate and growth hormone on biosynthesis of steroids in rats

Growth hormone (GH) and anabolic androgenic steroids (AAS) are commonly used in sports communities. Several studies have suggested an association between GH and AAS. We have investigated the impact of GH in rats treated with nandrolone decanoate (ND). Male Wistar rats received ND (15 mg/kg) every third day during three weeks and were subsequently treated with recombinant human GH (1.0 IU/kg) for ten consecutive days. Plasma samples were collected and peripheral organs (i.e. heart, liver, testis and thymus) were dissected and weighed. Concentration of thirteen endogenous steroids was measured in the rat plasma samples using high specificity LC–MS/MS methods. Seven steroids were detected and quantified, and concentrations of estrone, testosterone, and androstenedione were significantly different among the groups, while concentrations of pregnenolone, DHEA, 17-hydroxyprogesterone and corticosterone were not altered. Administration of rhGH alone altered the plasma steroid distribution, and the results demonstrated significantly increased concentrations of plasma estrone as well as decreased concentrations of testosterone and androstenedione in the ND-treated rats. Administration of rhGH to ND-pretreated rats did not reverse the alteration of the steroid distribution induced by ND. Administration of ND decreased the weight of the thymus, and addition of rhGH did not reverse this reduction. However, rhGH administration induced an enlargement of thymus. Taken together, the plasma steroid profile differed in the four groups, i.e. control, AAS, rhGH and the combination of AAS and rhGH treatment.     

Which features of UK farmland are important in retaining territories of the rapidly declining Turtle Dove Streptopelia turtur?

Capsule Turtle Doves continue to show a strong population decline; territories were more likely to be retained in areas with more nesting habitat, and more suitable foraging habitat.

Aim To determine which features of farmland in England are important for retaining Turtle Dove territories

Methods Fifty-eight grid squares with recent records of territorial Turtle Doves were resurveyed, and squares retaining Turtle Dove territories compared with those from which Turtle Doves had been lost.

Results Turtle Dove territories were detected in 48% of squares resurveyed. When correcting for the 70% detection rate of the survey methodology, territories were present in 66% of squares surveyed suggesting a 34% decline over a 2-year period. Established scrub and hedgerows?>?4 m tall positively influenced Turtle Dove presence and abundance, as did standing water. Bare ground and fallow had positive effects on Turtle Dove abundance whereas grazed land negatively impacted abundance.

Conclusion The positive effects of area of established scrub and volume of large hedgerows are likely to represent a declining density of birds selecting the best quality nest sites. We suggest instead that foraging habitat may be limiting distribution.     

Baboon phylogeny as inferred from complete mitochondrial genomes

Baboons (genus Papio) are an interesting phylogeographical primate model for the evolution of savanna species during the Pleistocene. Earlier studies, based on partial mitochondrial sequence information, revealed seven major haplogroups indicating multiple para‐ and polyphylies among the six baboon species. The most basal splits among baboon lineages remained unresolved and the credibility intervals for divergence time estimates were rather large. Assuming that genetic variation within the two studied mitochondrial loci so far was insufficient to infer the apparently rapid early radiation of baboons we used complete mitochondrial sequence information of ten specimens, representing all major baboon lineages, to reconstruct a baboon phylogeny and to re‐estimate divergence times. Our data confirmed the earlier tree topology including the para‐ and polyphyletic relationships of most baboon species; divergence time estimates are slightly younger and credibility intervals narrowed substantially, thus making the estimates more precise. However, the most basal relationships could not be resolved and it remains open whether (1) the most southern population of baboons diverged first or (2) a major split occurred between southern and northern clades. Our study shows that complete mitochondrial genome sequences are more effective to reconstruct robust phylogenies and to narrow down estimated divergence time intervals than only short portions of the mitochondrial genome, although there are also limitations in resolving phylogenetic relationships. Am J Phys Anthropol, 2013. © 2012 Wiley Periodicals, Inc.     

Macroinvertebrates as unreliable indicators of human disturbance in temporary depression wetlands of the south-western Cape, South Africa

Macroinvertebrates have a successful history of use as indicators of human impact in lotic environments. More recently, macroinvertebrate indices have been recommended for use in certain wetland types. Yet some authors do not recommend macroinvertebrates indices of wetland condition in areas with pronounced natural environmental heterogeneity. Our study provides a preliminary assessment of the feasibility of using macroinvertebrates for bioassessment of temporary isolated depression wetlands in the south-western Cape region of South Africa. We expected natural environmental heterogeneity among wetlands to exert a stronger influence on macroinvertebrates than human disturbance factors. Partitioning of the variation in macroinvertebrate assemblage composition that could be attributed to human disturbance factors (within and adjacent to wetlands), environmental variables and spatio-temporal factors indicated that environmental and spatio-temporal factors independent of human disturbances largely determined assemblage composition, whilst human disturbance played a relatively minor role. Linear regressions of taxon richness/diversity measures, individual families and a collation of metrics against measures of habitat transformation around wetlands and scores from a rapid assessment index of human disturbance revealed poor relationships. The univariate and multivariate patterns observed in this study do not lend themselves to the creation of a macroinvertebrate index of human disturbance for temporary wetlands in the region.     

Observations on Thorea ramosissimaBory (Batrachospermales,Thoreaceae), a freshwater red alga rarely recorded in the British Isles

The conspicuous macroscopic stage of the freshwater red alga Thorea ramosissima has been re-discovered in the River Thames after a lapse of almost 140 years. In the 1840s it was reported only from Walton-on-Thames, but is now known from 13 localities along a 133 km stretch between Oxford and Teddington. It is transient, often remaining undetected at known localities in subsequent years. All British records are assessed, especially 19th century collections from the Thames. The ecology and the morphology of the macroscopic stage are discussed.     

Novel inhibitors of bacterial virulence: Development of 5,6-dihydrobenzo[h]quinazolin-4(3H)-ones for the inhibition of group A streptococcal streptokinase expression

Resistance to antibiotics is an increasingly dire threat to human health that warrants the development of new modes of treating infection. We recently identified 1 (CCG-2979) as an inhibitor of the expression of streptokinase, a critical virulence factor in Group A Streptococcus that endows blood-borne bacteria with fibrinolytic capabilities. In this report, we describe the synthesis and biological evaluation of a series of novel 5,6-dihydrobenzo[h]quinazolin-4(3H)-one analogs of 1 undertaken with the goal of improving the modest potency of the lead. In addition to achieving an over 35-fold increase in potency, we identified structural modifications that improve the solubility and metabolic stability of the scaffold. The efficacy of two new compounds 12c (CCG-203592) and 12k (CCG-205363) against biofilm formation in Staphylococcus aureus represents a promising additional mode of action for this novel class of compounds.     

Plant proteomics in India and Nepal: current status and challenges ahead

Plant proteomics has made tremendous contributions in understanding the complex processes of plant biology. Here, its current status in India and Nepal is discussed. Gel-based proteomics is predominantly utilized on crops and non-crops to analyze majorly abiotic (49 %) and biotic (18 %) stress, development (11 %) and post-translational modifications (7 %). Rice is the most explored system (36 %) with major focus on abiotic mainly dehydration (36 %) stress. In spite of expensive proteomics setup and scarcity of trained workforce, output in form of publications is encouraging. To boost plant proteomics in India and Nepal, researchers have discussed ground level issues among themselves and with the International Plant Proteomics Organization (INPPO) to act in priority on concerns like food security. Active collaboration may help in translating this knowledge to fruitful applications.     

Nature of the slow relaxation of smooth muscle induced by a EP2 receptor agonist with a non-prostanoid structure

The remarkably slow onset/offset of relaxation of guinea-pig isolated trachea induced by a ‘non-prostanoid’ EP₂ receptor agonist, (o-(o-benzyloxy)-cinnamyl)-cinnamic acid (coded (L)-9), was investigated. (L)-9 kinetics was slightly faster on mouse trachea and considerably faster on rabbit vena cava. In each case, reversal of (L)-9 relaxation by the selective EP₂ antagonist ACA-23 was rapid and similar to other EP₂ agonists (e.g. ONO-AE1-259). On guinea-pig aorta, in the presence of extensive EP₂ receptor blockade, (L)-9 inhibited TP agonist-induced contraction more slowly than TP antagonists of similar affinity. The slower kinetics of (L)-9 appear to correlate with greater adventitial/submucosal barriers and thicker smooth muscle layers in the tissues examined. It is proposed that interactions of (L)-9 with EP₂ and TP receptors are not rate-limiting, rather diffusion to and from the centre of the muscle mass is retarded by the high lipophilicity of (L)-9 (logP=6.69; ONO-AE1-259=3.95).     

Identification and Characterisation CRN Effectors in Phytophthora capsici Shows Modularity and Functional Diversity

Phytophthora species secrete a large array of effectors during infection of their host plants. The Crinkler (CRN) gene family encodes a ubiquitous but understudied class of effectors with possible but as of yet unknown roles in infection. To appreciate CRN effector function in Phytophthora, we devised a simple Crn gene identification and annotation pipeline to improve effector prediction rates. We predicted 84 full-length CRN coding genes and assessed CRN effector domain diversity in sequenced Oomycete genomes. These analyses revealed evidence of CRN domain innovation in Phytophthora and expansion in the Peronosporales. We performed gene expression analyses to validate and define two classes of CRN effectors, each possibly contributing to infection at different stages. CRN localisation studies revealed that P. capsici CRN effector domains target the nucleus and accumulate in specific sub-nuclear compartments. Phenotypic analyses showed that few CRN domains induce necrosis when expressed in planta and that one cell death inducing effector, enhances P. capsici virulence on Nicotiana benthamiana. These results suggest that the CRN protein family form an important class of intracellular effectors that target the host nucleus during infection. These results combined with domain expansion in hemi-biotrophic and necrotrophic pathogens, suggests specific contributions to pathogen lifestyles. This work will bolster CRN identification efforts in other sequenced oomycete species and set the stage for future functional studies towards understanding CRN effector functions.