Changes in vegetation patterns on the margins of a constructed wetland after 10 years

Summary A constructed urban wetland in Adelaide was surveyed 18 months and 10 years after construction to see how shoreline vegetation, soil electrical conductivity (EC), texture and pH changed over time and to provide data for future site management. Multivariate analysis detected four plant associations at 18 months: salt‐tolerant taxa on conductive clays; a weed‐dominated community on lower EC soil; and two smaller waterlogged, low EC clusters dominated by Common Reed (Phragmites australis) and Sea Club‐Rush (Bolboschoenus caldwellii), respectively. At 10 years, site cover and heterogeneity was higher, with the margins dominated by Phragmites and salt‐tolerant species. EC was much lower and more uniform, and the soils were heavier and more alkaline. Managed storm water flushing apparently lowered soil EC, but possibly also disturbed the shoreline. However, weeds were still common, and the potential for domination by Phragmites at the expense of other native shoreline species means that ongoing monitoring and hydrological and vegetation management are essential to maintain site habitat diversity.     

Heme induces significant neutrophil adhesion in vitro via an NFκB and reactive oxygen species-dependent pathway

Molecular and Cellular Biochemistry - Intravascular hemolysis, a major manifestation of sickle cell disease (SCD) and other diseases, incurs the release of hemoglobin and heme from red blood cells,...     

Phylogenetic relationships within the ‘core’ Laureae (Litsea complex, Lauraceae) inferred from sequences of the chloroplast gene matK and nuclear ribosomal DNA ITS regions

A phylogenetic analysis of the core Laureae (Litsea complex) was conducted using the chloroplast gene matK and nuclear ribosomal DNA ITS sequences to investigate generic relationships and boundaries within the complex. Despite low genetic divergence for matK, rooting of the tree with Sassafras resulted in Iteadaphne as the basal member of the complex and five resolved clades: a Neolitsea clade and then Laurus, Parasassafras, Litsea and Lindera clades in a large polytomy with unresolved Lindera sections plus Umbellularia. A combined analysis of the data (identical to the ITS results) provided a more resolved phylogeny of the Laureae, with four major lineages: the Laurus, Litsea, Lindera and Actinodaphne II clades. These clades also appear to reflect the importance of inflorescence structure and ontogeny within the Laureae, as well as data from cuticular micromorphology, but there was no support for traditional generic characters such as 2- versus 4- celled anthers. As a result, genera such as Actinodaphne, Litsea, Neolitsea and Lindera were polyphyletic in all analyses. Parasassafras was related to Sinosassafras by the matK data, but distant from it in the ITS and combined analyses.     

Reduced plasma angiotensin II levels are reversed by hydroxyurea treatment in mice with sickle cell disease

Aims

Sickle cell disease (SCD) pathogenesis leads to recurrent vaso-occlusive and hemolytic processes, causing numerous clinical complications including renal damage. As vasoconstrictive mechanisms may be enhanced in SCD, due to endothelial dysfunction and vasoactive protein production, we aimed to determine whether the expression of proteins of the renin–angiotensin system (RAS) may be altered in an animal model of SCD.

Main methods

Plasma angiotensin II (Ang II) was measured in C57BL/6 (WT) mice and mice with SCD by ELISA, while quantitative PCR was used to compare the expressions of the genes encoding the angiotensin-II-receptors 1 and 2 (AT1R and AT2R) and the angiotensin-converting enzymes (ACE1 and ACE2) in the kidneys, hearts, livers and brains of mice. The effects of hydroxyurea (HU; 50–75 mg/kg/day, 4 weeks) treatment on these parameters were also determined.

Key findings

Plasma Ang II was significantly diminished in SCD mice, compared with WT mice, in association with decreased AT1R and ACE1 expressions in SCD mice kidneys. Treatment of SCD mice with HU reduced leukocyte and platelet counts and increased plasma Ang II to levels similar to those of WT mice. HU also increased AT1R and ACE2 gene expression in the kidney and heart.

Significance

Results indicate an imbalanced RAS in an SCD mouse model; HU therapy may be able to restore some RAS parameters in these mice. Further investigations regarding Ang II production and the RAS in human SCD may be warranted, as such changes may reflect or contribute to renal damage and alterations in blood pressure.     

Plastid phylogenomics and molecular evolution of Alismatales

Past phylogenetic studies of the monocot order Alismatales left several higher‐order relationships unresolved. We addressed these uncertainties using a nearly complete genus‐level sampling of whole plastid genomes (gene sets representing 83 protein‐coding and ribosomal genes) from members of the core alismatid families, Tofieldiaceae and additional taxa (Araceae and other angiosperms). Parsimony and likelihood analyses inferred generally highly congruent phylogenetic relationships within the order, and several alternative likelihood partitioning schemes had little impact on patterns of clade support. All families with multiple genera were resolved as monophyletic, and we inferred strong bootstrap support for most inter‐ and intrafamilial relationships. The precise placement of Tofieldiaceae in the order was not well supported. Although most analyses inferred Tofieldiaceae to be the sister‐group of the rest of the order, one likelihood analysis indicated a contrasting Araceae‐sister arrangement. Acorus (Acorales) was not supported as a member of the order. We also investigated the molecular evolution of plastid NADH dehydrogenase, a large enzymatic complex that may play a role in photooxidative stress responses. Ancestral‐state reconstructions support four convergent losses of a functional NADH dehydrogenase complex in Alismatales, including a single loss in Tofieldiaceae.     

Proinflammatory cytokine genes are constitutively overexpressed in the heart in experimental systemic lupus erythematosus: a brief communication

The heart is one of a number of organs that may be affected in systemic lupus erythematosus (SLE), a prototypic autoimmune disease. Potential anatomical sites of involvement include the myocardium, pericardium, endocardium, valves, conduction system and blood vessels that subserve the heart. Typically, the severity of cardiovascular disease in lupus correlates with the degree of systemic inflammation, which is mirrored by the level of C-reactive protein (CRP) in the plasma. C-reactive protein, in turn is regulated by proinflammatory cytokines, such as interleukins (ILs) 1beta and 6. These cytokines have been found in functionally and/or structurally damaged areas of the heart and have been implicated in disease pathogenesis. It has been assumed that the source of these putatively pathogenetically relevant cytokines in the compromised heart is infiltrating mononuclear cells. This study tests the hypothesis that cardiomyocytes per se may contribute to proinflammatory cytokine production in the setting of systemic inflammation. Using as the experimental model MRL/MpJ-Tnfrs6(lpr) (MRL-lpr/lpr) mice, which spontaneously manifest an autoimmune syndrome that has clinical features of SLE, we show that ventricular homogenates and ventricular cardiomyocytes constitutively overexpress genes encoding the proinflammatory cytokines IL-1beta, IL-6, IL-10, and gamma interferon. The results suggest the possibility that proinflammatory cytokines emanating from the heart may actually contribute to the high levels of CRP that appear to aid in predicting subsequent cardiac events. Viewed in this setting, CRP becomes a footprint of an ongoing pathogenic process mediated, in part, by the heart muscle itself.     

Plastid genomes and deep relationships among the commelinid monocot angiosperms

The commelinid monocots comprise the orders Arecales (A), Commelinales (C), Poales sensu Angiosperm Phylogeny Group III (APGIII) (P), Zingiberales (Z), plus the unplaced family Dasypogonaceae (D), collectively containing numerous economically and ecologically important species and encompassing enormous morphological diversity. Commelinids are supported as monophyletic based on anatomy and molecular data; however, relationships among major commelinid groupings conflict among previous studies, representing a long‐standing problem in monocot systematics, with major implications for interpretations of character evolution. In more recent analyses, with whole‐plastome sampling largely focused on Poales, areas of conflict remain, suggesting the need for closer investigation of relationships and support. Here, we increased sampling of plastomes among non‐Poalean commelinid orders to investigate deep nodal support. Analysis of 83 plastid genes recovered relationships as ((A, D) (ZC, P)) with robust support, regardless of reconstruction method (parsimony/likelihood). However, conflict among genes was evident when grouped by genomic region. Cumulative analyses of genes ranked by decreasing numbers of informative characters indicated continued fluctuation in support, even as small genes were added to a nearly complete matrix, contrary to the expected pattern of stabilization in support. Topology tests among major commelinid groups suggested that the data were not powerful enough to reject all alternatives. This study provides clues to the limits of the plastid genome for resolving deep relationships among the commelinid monocots.     

Phylogeny of Neolitsea (Lauraceae) inferred from Bayesian analysis of nrDNA ITS and ETS sequences

ITS and ETS-based sequence analyses of 29 Neolitsea, six Actinodaphne and five outgroup `core' Laureae taxa show that Neolitsea is monophyletic with two large subclades, whereas most of the sampled Actinodaphne are paraphyletic below it. Inflorescence features appear to be among the more reliable morphological characters for explaining relationships between Neolitsea and other genera within the `core' Laureae, with the Neolitsea/Actinodaphne clade defined by inflorescences lacking vegetative terminal buds in the main axis. Although the relationships within Neolitsea are still poorly resolved, there is enough structure to suggest that the genus seems to divide into two groups based on fruit shape: elliptic or ovoid, versus globose, although more evidence (both molecular and morphological) and wider taxon sampling are required to confirm this.     

Morphology of Hydatellaceae, an anomalous aquatic family recently recognized as an early-divergent angiosperm lineage

The family Hydatellaceae was recently reassigned to the early-divergent angiosperm order Nymphaeales rather than the monocot order Poales. This dramatic taxonomic adjustment allows comparison with other early-divergent angiosperms, both extant and extinct. Hydatellaceae possess some monocot-like features that could represent adaptations to an aquatic habit. Ecophysiological parallels can also be drawn from fossil taxa that are known from small achene-like diaspores, as in Hydatellaceae. Reproductive units of Hydatellaceae consist of perianthlike bracts enclosing several pistils and/or stamens. In species with bisexual reproductive units, a single unit resembles an "inside-out" flower, in which stamens are surrounded by carpels that are initiated centrifugally. Furthermore, involucre development in Trithuria submersa, with delayed growth of second whorl bracts, resembles similar delayed development of the second perianth whorl in Cabomba. Several hypotheses on the homologies of reproductive units in Hydatellaceae are explored. Currently, the most plausible interpretation is that each reproductive unit represents an aggregation of reduced unisexual apetalous flowers, which are thus very different from flowers of Nymphaeales. Each pistil in Hydatellaceae is morphologically and developmentally consistent with a solitary ascidiate carpel. However, ascidiate carpel development, consistent with placement in Nymphaeales, is closely similar to pseudomonomerous pistil development as in Poaes.