The influence of selenium on expression levels of the gene in .

In this study, the effects of selenium on the microalgae were examined. Four groups of were cultivated using Bristol medium: group I (control), no sodium selenite (Se); group II, 1 µM Se; group III, 10 µM Se; and group IV, 100 µM Se. Algal biomass samples were collected for biochemical evaluation and gene expression studies on the 21st day of cultivation. The following parameters were investigated: chlorophyll a (Cl), chlorophyll b (Cl) and total carotene content, total protein, and total glutathione (GSH) and malondialdehyde (MDA) levels. Gene expression levels of large subunits of Rubisco () were analyzed using real-time quantitative polymerase chain reaction. Total Cl and total carotene in s decreased in high concentrations of Se (100 µM) (around 23 and 42%, respectively) when compared to controls while, Cl content increased by about 10%. 10 µM of Se led to increased GSH levels (3.04 ± 0.02 µg GSH/mg protein) and decreased MDA levels (2.02 ± 0.1 µmol MDA/mg protein) when compared to control groups (1.18 ± 0.04 µg GSH/mg protein and 0.94 ± 0.23 µmol MDA/mg protein), while a significant decrease in GSH and an increase in MDA levels in the presence of 100 µM Se showed the opposite effect. gene expression increased 1.76 ± 1.37-fold and 0.86 ± 1.33-fold in 10 and 100 µM selenium experiments when compared to control groups. Our results suggest both pro-oxidant and antioxidant activities of Se on and upregulation of the gene for the first time. Treatment with low concentrations of Se improves the antioxidant features of the microalgae, .