Search

Background: Phytoremediation is affected by physical and chemical properties of the soil such as soil pH, moisture, and nutrient content. Soil pH is a key element influencing Cd bioavailability and can be easily adjusted in agricultural practices. The soil pH level may relate to the effectiveness of phytoremediation; however, this has not been extensively investigated. In the current study, we evaluated the effect of Cd contamination level (0.56 and 0.92 mg/kg) and soil pH (5, 6, and 7) on Cd accumulation and allocation in Artemisia argyi, a fast-growing perennial crop. Results: Our results indicated that higher soil Cd concentrations reduce A. argyi biomass, and the loss of the root mass was particularly significant. Higher soil pH decreased Cd content in stems and roots of A. argyi cultivated in moderately Cd-polluted soil, and increased Cd content in stems and roots of the plant grown in low Cd-polluted soil. Higher soil pH decreased the percentage of Cd distributed in the soluble fraction and cell walls and increased the percentage of Cd in the organelles of leaf cells for moderate soil Cd levels. The bioconcentration and translocation factor exceeded 4.0 and 1.0, respectively, across all tested treatments, indicating that A. argyi is a promising candidate for phytoremediation. Notably, the effects of soil pH on Cd accumulation and subcellular distribution in A. argyi differed between low and moderately Cd-contaminated soils. Conclusion: Adjustments to soil pH based on the degree of Cd contamination can enhance Cd extraction by A. argyi, thereby reducing the overall remediation cycle of cadmium-polluted paddy fields of South China. [ABSTRACT FROM AUTHOR]

Riparian vegetation is crucial for maintaining terrestrial and aquatic biodiversity, but it is threatened by land-use activities. To assess the ecological impacts of riparian vegetation conversion to an oil tea (Camellia oleifera) plantation, we quantified the responses of small mammals in two natural habitats (mature forest and flood-meadow) and in Camellia forests at the community, population, and individual level. We found that the community diversity was similar between Camellia forests and mature forests, but higher than the flood-meadow. Meanwhile, the community composition differed across three habitats, with Camellia forests favoring habitat generalist species. At the population level, Camellia forests and flood-meadow had a similar population density, which were higher than mature forests. At the individual level, Rattus nitidus was less sensitive to this conversion, but the body condition index of Niviventer confucianus was higher in Camellia forests than in mature forests, and Apodemus agrarius in Camellia forests had more ectoparasite load than in the flood-meadow, indicating a species-specific response to the impacts of oil tea plantation. Our study highlights that the occurrence of habitat generalist species and high ectoparasite loads may threaten regional biodiversity and increase the risk of parasite transmission with enlarging the oil tea plantation area within riparian zones. [ABSTRACT FROM AUTHOR]

Cytochrome b (cyt b) gene complete sequences (1143bp) of Takydromus sylvaticus were sequenced. In order to clarify the phylogenetic position of the Takydromus sylvaticus, we investigated the phylogeny of 15 Takydromus spp. distributed in East-Asia by Maximum Parsimony (MP), Bayesian Inference (BI), and Maximum Likelihood (ML) methods using DNA fragments of cyt b genes. The results supported that the Platyplacopus merged into Takydromus and negated the validity of Platyplacopus. Furthermore, the prediction of tertiary structures of cyt b exhibited the CD loop region contain two short helices forming a hairpin arrangement, namely cd1 and cd2. Thermostability analysis shows that the CD-loop region is unstable thermodynamically and may provide mobility to amino acids located at the heme, and might provide high flexibility to the top of ISP (iron-sulfur protein) and the cavity region of Qo binding site. It suggested that the two short helices of CD loop region of cyt b was a dominating portion for ISP binding site.

Author(s): Ying Yu [1]; Jinjin Fan [1]; Xin-Sheng Chen [1, 5]; Dairong Wang [1]; Andres J Klein-Szanto [2]; Robert L Campbell [3]; Garret A FitzGerald [1]; Colin D Funk (corresponding [...]

Targeted disruption of 5-lipoxygenase gene by homologous recombination in embryonic stem cells establishes the physiological importance of leukotrienes, a class of biological mediators of inflammation and anaphylaxis. The observed 5-lipoxygenase-deficient mice show resistance to the harmful effects of endotoxin shock induced by the platelet-activating factor and confirm that leukotrienes are vital to the pathophysiology of specific inflammatory states. Mast cells release chemotactic leukotrienes that facilitate neutrophil recruitment during early inflammatory insult.

The wetland sedge Carex brevicuspis reproduces vegetatively by producing short rhizomes to form clumping ramets phalanx) and long rhizomes to form spreading ramets (guerrilla), resulting in a combined growth form. As an initial step towards understanding the adaptation of Carex growth strategies to seasonal fluctuations in wetland habitats, we investigated the density and composition of C. brevicuspis rhizome populations immediately after flooding (November), in winter (January), in spring (March), and before flooding (May) in the Dongting Lake wetlands, China. The total rhizome density peaked in winter and was lowest before flooding. A large rhizome population in winter may enable C. brevicuspis to survive the seasonal cold weather and recruit a shoot population in the spring. A small rhizome population before flooding may optimize reproductive allocations and be a strategy for enduring the long flooding season. Regardless of date, short rhizomes comprised the majority of the rhizome population (73.0% in March to 98.2% in May). This indicates that C. brevicuspis primarily uses a phalanx growth strategy to utilize locally abundant resources in wetlands. The percentage of long rhizomes in the rhizome population varies significantly between seasons (1.8% in May to 27.0% in March), indicating that growth form also changes with seasonal fluctuation of wetland habitats. The results show that C. brevicuspis may adapt to seasonal changes in wetland habitats through changes in demography of rhizome populations. [ABSTRACT FROM AUTHOR]

Based on multi-temporal Land sat MSS/ TM/ ETM+ images, and by using decision tree method, this paper extracted the areas of emergent herbaceous wetlands with different water levels in 1989-2011 in the East Dongting Lake, China. The change characteristics and change trends of the emergent herbaceous wetlands areas were investigated based on the DEM data and the daily water level data from the Chenglingji Hydrological Station. The area of the emergent herbaceous wet-lands was significantly affected by water level (R2 =0. 875, P<0. 001), presenting a significant linear relationship between the two. Moreover, the emergent herbaceous wetlands area decreased with increasing water level. The higher the water level, the smaller the effects of the water level on the emergent area were. The emergent area changed regularly with water level. In January-July, water level increased, and the emergent area decreased; in July-December, it was opposite. In 1989- 2011, the areas of emergent herbaceous wetlands had a continual increase. The newly emergent herbaceous wetlands area was mainly transformed from mudflat. The emergent herbaceous wetlands expansion was the co-effects of the increase of the emergent herbaceous wetlands areas at different elevations, and the rapid expansion of the emergent herbaceous wetlands in low bottomland (22- 25 m of Yellow Sea elevation) played the most important role in the expansion. The change of water level at different elevations was the dominant cause for the changes of emergent herbaceous wetlands areas in the East Dongting Lake in the past 20 years. [ABSTRACT FROM AUTHOR]