The Natural History of Aconitum noveboracense Gray (Northern Monkshood), a Federally Threatened Species

Aconitum noveboracense Gray (Ranunculaceae), commonly known as northern monkshood, is a federally threatened herbaceous perennial that occurs in disjunct populations in Iowa, Wisconsin, Ohio and New York. It appears to be a glacial relict, existing today only in unique areas with cool, moist microenvironments, such as algific talus slopes. Field studies reveal that A. noveboracense has a complex life history. Perennation of individual plants occurs through the annual production of daughter tubers. Vegetative reproduction is commonly observed, and can occur by means of aerial and subterranean bulbils, as well as by development of adventitious root buds. Populations also reproduce sexually and often produce large numbers of seeds and seedlings, though herbivore damage to inflorescences can sometimes significantly reduce seed production. The seeds possess a high degree of viability and germinate readily when exposed to an appropriate stratification regime. Taken together, these life history traits appear to make A. noveboracense populations long-lived and quite resilient to environmental perturbations, thus making the species a promising candidate for recovery through habitat protection

A floristic survey of Benedict Prairie (Kenosha County, Wisconsin)

Benedict Prairie is a small railroad prairie that is owned and managed by the University of Wisconsin - Milwaukee Field Station. A floristic survey of the 2.5 ha site was conducted from 1988 to 1990. A total of 191 species, representing 51 families were identified, including Asclepias purpurascens and Parthenium integrifolium, which are protected in Wisconsin. This list was compared to two others compiled previously for the site. Compilation of all three lists brings the total number of species recorded from the site to 231, but reveals that a number of species appear to have been extirpated

Correlated sexual selection on male genitalia, copulatory performance and nuptial gifts in a bushcricket (Orthoptera: Tettigoniidae) indicated by allometric scaling

We adopt an allometric framework of scaling relationships for comparison between mating-related traits in the middle European bushcricket Roeseliana roeselii (Hagenbach, 1822). Eight characters, covering ontogenetic fitness (size traits; fixed at final moult), male condition (mass traits) and mating motivation (reproductive behaviours), were analysed in unrestricted matings and in matings involving genital manipulation. Shortening the male titillators had no effect on mating-related traits in males. However, titillators, known to be under sexual selection, scale hyperallometrically, with larger males possessing proportionally longer titillators, performing more titillator movements and exhibiting a reduced duration of copulation. Scaling was also hyperallometric for spermatophore mass, with larger males being heavier and transferring heavier nuptial gifts. Both titillator length and spermatophore mass might be condition-dependent indicators, because their variances were nearly twice as large those of body size or body mass. Mass traits were also dynamic, increasing by 11% for male body mass and 17% for spermatophore mass between the first and second matings. Sexual selection by female choice seems to favour larger trait size in the bushcricket R. roeselii, acting in concert on titillator length, intensity of titillator movements and spermatophore mass.Peer Reviewe

Tyrosine, Cysteine, and S-Adenosyl Methionine Stimulate In Vitro [FeFe] Hydrogenase Activation

Background: [FeFe] hydrogenases are metalloenzymes involved in the anaerobic metabolism of H2. These proteins are distinguished by an active site cofactor known as the H-cluster. This unique [6Fe–6S] complex contains multiple non-protein moieties and requires several maturation enzymes for its assembly. The pathways and biochemical precursors for H-cluster biosynthesis have yet to be elucidated. Principal Findings: We report an in vitro maturation system in which, for the first time, chemical additives enhance [FeFe] hydrogenase activation, thus signifying in situ H-cluster biosynthesis. The maturation system is comprised of purified hydrogenase apoprotein; a dialyzed Escherichia coli cell lysate containing heterologous HydE, HydF, and HydG maturases; and exogenous small molecules. Following anaerobic incubation of the Chlamydomonas reinhardtii HydA1 apohydrogenase with S-adenosyl methionine (SAM), cysteine, tyrosine, iron, sulfide, and the non-purified maturases, hydrogenase activity increased 5-fold relative to incubations without the exogenous substrates. No conditions were identified in which addition of guanosine triphosphate (GTP) improved hydrogenase maturation. Significance: The in vitro system allows for direct investigation of [FeFe] hydrogenase activation. This work also provides a foundation for studying the biosynthetic mechanisms of H-cluster biosynthesis using solely purified enzymes and chemical additives

Purple loosestrife (Lythrum salicaria): Its status in Wisconsin and control methods

Data were gathered in 1984 on the distribution, size, and habitat of populations of purple loosestrife in Wisconsin. Lythrum salicaria was found throughout Wisconsin, but most populations were still small and amenable to eradication with spot applications of herbicide. We compared the effectiveness of three dosages of glyphosate herbicide for eradicating small populations of purple loosestrife. High dosage treatments killed a slightly higher percentage of loosestrife than low dosage, but also caused much greater destruction of desirable perennial vegetation. The increased disturbance associated with high dosage, led to a high density of purple loosestrife seedlings in the following year. Low dosages of glyphosate herbicides are, therefore, recommended for control of L salicaria

A [4Fe-4S]-Fe(CO)(CN)-L-cysteine intermediate is the first organometallic precursor in [FeFe] hydrogenase H-cluster bioassembly.

Biosynthesis of the [FeFe] hydrogenase active site (the 'H-cluster') requires the interplay of multiple proteins and small molecules. Among them, the radical S-adenosylmethionine enzyme HydG, a tyrosine lyase, has been proposed to generate a complex that contains an Fe(CO)2(CN) moiety that is eventually incorporated into the H-cluster. Here we describe the characterization of an intermediate in the HydG reaction: a [4Fe-4S][(Cys)Fe(CO)(CN)] species, 'Complex A', in which a CO, a CN- and a cysteine (Cys) molecule bind to the unique 'dangler' Fe site of the auxiliary [5Fe-4S] cluster of HydG. The identification of this intermediate-the first organometallic precursor to the H-cluster-validates the previously hypothesized HydG reaction cycle and provides a basis for elucidating the biosynthetic origin of other moieties of the H-cluster

Development of vegetation over nine years in a planted field station prairie

We studied the development of vegetation in a small area at the UWM Field Station planted with prairie species in 1986. The species and quantities of seed and seedlings planted in 1986 were recorded. We sampled the vegetation using permanent quadrats in 1988and 1994. Native prairie species were already well established in the area in 1988. There was, however, a dramatic change in the composition of the vegetation between 1988 and 1994. The number of native prairie species increased slightly and the number of non-prairie species decreased substantially, so that in 1988, 51% of species were native prairie plants and this figure increased to 62% in 1994. The sum of the mean cover of all plant species almost tripled between 1988 and 1994, primarily due to a large increase in cover of grass species. The relative dominance of several species changed markedly over the six years between samples

Cell-free H-cluster Synthesis and [FeFe] Hydrogenase Activation: All Five CO and CN− Ligands Derive from Tyrosine

[FeFe] hydrogenases are promising catalysts for producing hydrogen as a sustainable fuel and chemical feedstock, and they also serve as paradigms for biomimetic hydrogen-evolving compounds. Hydrogen formation is catalyzed by the H-cluster, a unique iron-based cofactor requiring three carbon monoxide (CO) and two cyanide (CN−) ligands as well as a dithiolate bridge. Three accessory proteins (HydE, HydF, and HydG) are presumably responsible for assembling and installing the H-cluster, yet their precise roles and the biosynthetic pathway have yet to be fully defined. In this report, we describe effective cell-free methods for investigating H-cluster synthesis and [FeFe] hydrogenase activation. Combining isotopic labeling with FTIR spectroscopy, we conclusively show that each of the CO and CN− ligands derive respectively from the carboxylate and amino substituents of tyrosine. Such in vitro systems with reconstituted pathways comprise a versatile approach for studying biosynthetic mechanisms, and this work marks a significant step towards an understanding of both the protein-protein interactions and complex reactions required for H-cluster assembly and hydrogenase maturation