ROS-Scavengers, Osmoprotectants and Violaxanthin De-Epoxidation in Salt-Stressed with Different Tocopherol Composition.

To determine the role of α- and γ-tocopherol (TC), this study compared the response to salt stress (200 mM NaCl) in wild type (WT) (L.) Heynh. And its two mutants: (1) totally TC-deficient ; (2) accumulating γ-TC instead of α-TC; and (3) transgenic line overaccumulating α-TC.

Violaxanthin conversion by recombinant diatom and plant de-epoxidases, expressed in Escherichia coli - comparative analysis.

The purpose of this research was to obtain recombinant violaxanthin de-epoxidases (VDEs) from two species. The first one was VDE of Arabidopsis thaliana (L.) Heynh.

Diadinoxanthin de-epoxidation as important factor in the short-term stabilization of diatom photosynthetic membranes exposed to different temperatures.

The importance of diadinoxanthin (Ddx) de-epoxidation in the short-term modulation of the temperature effect on photosynthetic membranes of the diatom Phaeodactylum tricornutum was demonstrated by electron paramagnetic resonance (EPR), Laurdan fluorescence spectroscopy, and high-performance liquid chromatography. The 5-SASL spin probe employed for the EPR measurements and Laurdan provided information about the membrane area close to the polar head groups of the membrane lipids, whereas with the 16-SASL spin probe, the hydrophobic core, where the fatty acid residues are located, was probed. The obtained results indicate that Ddx de-epoxidation induces a two component mechanism in the short-term regulation of the membrane fluidity of diatom thylakoids during changing temperatures.

Temperature effect on growth, and selected parameters of Phaeodactylum tricornutum in batch cultures.

The effect of optimal and stress temperatures on the growth kinetics of the Phaeodactylum tricornutum CCAP/1055/1 strain (a model diatom with a known genome sequence) in batch cultures was examined. The analysis of the obtained results showed two phases of culture growth. There were significant positive correlations between OD increase of chlorophyll a chlorophyll c and protein concentration at different temperatures.

Expression of three diadinoxanthin de-epoxidase genes of Phaeodacylum tricornutum in Escherichia coli Origami b and BL21 strain.

In the diadinoxanthin cycle the epoxy group is removed from diadinoxanthin and diatoxanthin is created. This conversion takes place e.g.

Zeaxanthin epoxidation - an in vitro approach.

Zeaxanthin epoxidase (ZE) is an enzyme operating in the violaxanthin cycle, which is involved in photoprotective mechanisms. In this work model systems to study zeaxanthin (Zx) epoxidation were developed. Two assay systems are presented in which epoxidation of Zx was observed.