Biomass growth variation and phytoextraction potential of four Salix varieties grown in contaminated soil amended with lime and wood ash

Abstract

In a greenhouse experiment, plant growth and copper (Cu) and zinc (Zn) uptake by four Salix cultivars grown in Cu and Zn contaminated soils collected from a mining area in Finland were tested to assess their suitability for phytoextraction. The cultivars displayed tolerance to heavily contaminated soils throughout the experiment. After uptake, total mean Cu concentrations in the leaves, shoots and roots in all cultivars and treatments ranged from 163 to 474?mg kg^?1 and mean Zn concentrations ranged from 776 to 1823?mg kg^?1. Lime and wood ash addition increased dry biomass growth (25–43%), chlorophyll fluorescence (Fv/Fm) values (3–6%), the translocation factor (TF) (15–60% for Cu; 10–25% for Zn), the bio-concentration factor (BCF) (40–85% for Cu; 70–120% for Zn), and metal uptake (55–70% for Cu; 50–65% for Zn) compared to unamended treatment across all cultivars. The results revealed that Salix cultivars have the potential to take up and accumulate significant amounts of Cu and Zn. Cultivar Klara (Salix viminalis × S. schwerinii × S. dasyclados) was found to be the most effective cultivar for phytoextraction since it displayed greater dry biomass production, Fv/Fm, TF, BCF values and uptake percentage rates of Cu and Zn compared to the other three cultivars. This study indicates that further research is needed to clarify the wider phytoextraction capabilities of different Salix cultivars.     

Genome-wide Association Study in a High-Risk Isolate for Multiple Sclerosis Reveals Associated Variants in STAT3 Gene

Genetic risk for multiple sclerosis (MS) is thought to involve both common and rare risk alleles. Recent GWAS and subsequent meta-analysis have established the critical role of the HLA locus and identified new common variants associated to MS. These variants have small odds ratios (ORs) and explain only a fraction of the genetic risk. To expose potentially rare, high-impact alleles, we conducted a GWAS of 68 distantly related cases and 136 controls from a high-risk internal isolate of Finland with increased prevalence and familial occurrence of MS. The top 27 loci with p < 10⁻⁴ were tested in 711 cases and 1029 controls from Finland, and the top two findings were validated in 3859 cases and 9110 controls from more heterogeneous populations. SNP (rs744166) within the STAT3 gene was associated to MS (p = 2.75 × 10⁻¹⁰, OR 0.87, confidence interval 0.83–0.91). The protective haplotype for MS in STAT3 is a risk allele for Crohn disease, implying that STAT3 represents a shared risk locus for at least two autoimmune diseases. This study also demonstrates the potential of special isolated populations in search for variants contributing to complex traits.     

PROTEIN PHOSPHATASE INHIBITORY ACTIVITY IN EXTRACTS OF CULTURED BLUE-GREEN ALGAE (CYANOPHYTA)1

A large-scale screening program was initiated to evaluate laboratory-cultured blue-green algae (cyanobacteria) as a source of novel compounds with inhibitory activity against certain serine/threonine protein phosphatases. Over 1600 extracts, representing 816 cyanophyte strains with broad habitat and taxonomic diversity, were screened. Inhibitors were identified in extracts produced from all orders tested except Chamaesiphonales, and the family Stigonemataceae was found to contain proportionally more inhibitors as compared to the total screen.     

Identification, purification, and characterization of a novel serine/threonine protein phosphatase from bovine brain.

A novel serine/threonine protein phosphatase is identified, and the catalytic subunit, obtained from a detergent extraction of the pellet generated by a 100,000 x g centrifugation of a whole bovine brain homogenate, is purified and characterized. The protein phosphatase, designated as PP3, has a Mr of 36,000, does not require divalent cations for activity, is stimulated rather than inhibited by inhibitor 2, is inhibited by both okadaic acid and microcystin-LR with an intermediate IC50 compared to type 1 and type 2A protein phosphatases, and preferentially dephosphorylates the beta subunit of phosphorylase kinase. Substrate specificity, immunoblotting with type-specific antisera, and the amino acid sequences of peptides derived from PP3 indicate that PP3 is not an isoform of any known serine/threonine protein phosphatase.     

Infants with univentricular heart have reduced heart rate and blood pressure responses to side motion and altered responses to head-up tilt.

Cardiovascular control was studied in infants with univentricular heart (UVH). Side motion tests and 45-s 45 degrees head-up tilt tests were performed in 11 control and 9 UVH infants at the age of 13 +/- 3.2 wk. In addition, heart rate (HR) reactions to spontaneous arousals and HR variability during slow-wave sleep (SWS) were determined. All UVH infants had been hypoxic for several weeks, and during the sleep study the mean arterial oxyhemoglobin saturation was 82 +/- 5%. Tests were done at night during SWS, confirmed by polysomnographic recording. Continuous beat-to-beat blood pressure (BP) was measured. In the side-motion tests, control infants consistently showed a transient increase in HR and BP. This response was markedly reduced in all of the UVH infants (P < 0.0001). In tilt tests, the UVH infants showed normal BP responses, but, although a sustained 2.0% decrease in HR was observed in the controls, the UVH infants presented with a sustained 2.6% mean HR increase (P = 0.005). The UVH infants also showed attenuated HR acceleration during spontaneous arousals (P = 0.01), but HR variability did not differ significantly from the controls. In conclusion, UVH infants with chronic hypoxia exhibit defective vestibulosympathetic pathways, as expressed by an absence of acute HR and BP reactivity to side motion. HR reactions to postural challenge and spontaneous arousal are also altered. Autonomic function abnormalities in these infants are suggested to be secondary to hypoxia.     

Phenolic extractives in Salix caprea wood and knots

Salix caprea stemwood and knots were found to contain the phenolic extractives vanillic acid, 3-p-coumaryl alcohol, coniferyl alcohol, sinapylaldehyde, dihydrokaempferol, catechin, naringenin, gallocatechin, dihydromyrcetin and taxifolin. The knots contained larger quantities of flavonoids than did stemwood of the same tree.