A Comparative Study of Soluble Protein Extractions of Populus deltoides × （ Trichocarpa × Deltoides） for 2-DE

Background： The disclosure of the poplar genome strengthens its position as well-established model organism. Populus has been subject of several proteome studies, but up to date no comparative study was performed on the extraction method of soluble proteins for this species. The extraction is the most critical step in two-dimensional gel electrophoresis and each extraction method has its advantages, disadvantages and limitations. Therefore protein extraction methods should be optimized for each tissue before starting an experimental setup. In prospect of future DIGE （Differential Gel electrophoresis） experiments for the investigation of the effects of cadmium and inoculation with plant growth promoting bacteria at the proteome level, the aim of this study was to optimize an extraction method for soluble proteins of poplar leaves and roots. Results： The acetone-phenol extraction method was found to be the most suited, rendering a high spot number and low background interference. During further optimization, several critical steps in the extraction method were revealed. Conclusion： Aiming to optimize the extraction of soluble leaf and root proteins of Populus deltoides × （trichocarpa× deltoides） compatible with DIGE analysis, a protocol rendering high reproducibility, low background interference and a high spot number was established, however no novel insights were acquired.

Assessment of Methods for Determining Bioavailability of Trace Elements in Soils: A Review

Trace element-contaminated soils(TECSs) are one of the consequences of the past industrial development worldwide. Excessive exposure to trace elements(TEs) represents a permanent threat to ecosystems and humans worldwide owing to the capacity of metal(loid)s to cross the cell membranes of living organisms and of human epithelia, and their interference with cell metabolism.Quantification of TE bioavailability in soils is complicated due to the polyphasic and reactive nature of soil constituents. To unravel critical factors controlling soil TE bioavailability and to quantify the ecological toxicity of TECSs, TEs are pivotal for evaluating excessive exposure or deficiencies and controlling the ecological risks. While current knowledge on TE bioavailability and related cumulative consequences is growing, the lack of an integrated use of this concept still hinders its utilization for a more holistic view of ecosystem vulnerability and risks for human health. Bioavailability is not generally included in models for decision making in the appraisal of TECS remediation options. In this review we describe the methods for determining the TE bioavailability and technological developments, gaps in current knowledge, and research needed to better understand how TE bioavailability can be controlled by sustainable TECS management altering key chemical properties, which would allow policy decisions for environmental protection and risk management.