In the present study, [(35)S]sulphur flux from external sulphate into glutathione (GSH) and proteins was analysed to check whether APR controls the

flux through the sulphate assimilation pathway in poplar roots under some stress conditions and in transgenic poplars. (i) O-Acetylserine (OAS) induced APR activity and the sulphur flux into GSH. (ii) The herbicide Acetochlor induced APR activity and results in a decline of GSH. Thereby the sulphur flux into GSH or protein remained unaffected. (iii) Cd treatment increased APR activity without any changes in sulphur flux but lowered sulphate uptake. Several transgenic poplar plants that were SYN-117 cell line manipulated in sulphur metabolism were also analysed. (i) Transgenic poplar plants that overexpressed the gamma-glutamylcysteine synthetase (gamma-ECS) gene, the enzyme catalysing the key step in GSH formation, showed an increase in sulphur flux into GSH and sulphate uptake when gamma-ECS was targeted to the cytosol, while no changes in sulphur flux were observed when gamma-ECS was targeted to plastids. (ii) No effect on sulphur flux was observed when the sulphite oxidase (SO) gene from Arabidopsis thaliana, which catalyses the back reaction of APR, that is

the reaction from sulphite to sulphate, was overexpressed. (iii) When Lemna minor APR was overexpressed in poplar, APR activity increased as expected, but no changes BAY 80-6946 price in sulphur flux were observed. For all of these experiments the flux control coefficient for APR was calculated. APR as a controlling step in sulphate assimilation seems obvious under OAS treatment, in gamma-ECS and SO overexpressing poplars. A possible loss of control under certain conditions, that is Cd treatment, Acetochlor treatment,

and in APR overexpressing poplar, is discussed.”
“We have investigated the evolution of the magnetic transport properties as a function of short annealing time in CoFeB/MgO/CoFeB based magnetic tunnel junctions (MTJs) with a free layer of 2 nm. It is found that the hysteresis behaviors in magnetoresistance (MR) loops disappear in samples annealed for 17 min. The linear region between MR and the applied field gradually increases. The MR loops without hysteresis can be well fitted by using the superparamagnetism theory, suggesting the formation of superparamagnetic particles learn more in the free layer during the high temperature annealing. The control of MTJ properties with annealing time is desirable in magnetic field sensor productions. (C) 2010 American Institute of Physics. [doi:10.1063/1.3496663]“
“Random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) analysis were applied to 74 individual plants of Piper spp in Hainan Island. The results showed that the SRAP technique may be more informative and more efficient and effective for studying genetic diversity of Piper spp than the RAPD technique.