Abstract: Taking Monoraphidium sp. QLY-1 as the research object, the effects of different concentrations of melatonin (MT) on the lipid content, expression of lipogenic genes, physiological and biochemical properties, as well as the intracellular levels of reactive oxygen species (ROS) and glutathione (GSH) under salinity stress were preliminarily investigated. The results showed that under 10 μmol/L melatonin treatment, the lipid content of the cells reached 51.74%, which was 1.21 times higher than that of the salt stress group. Meanwhile, the protein and carbohydrate contents were both decreased as compared to the control. And the relative expression levels of me and accD, the lipid synthesis-related genes, were 1.75-and 1.40-folds higher than the control. Furthermore, the addition of MT reduced the levels of ROS and GSH in the algal cells, alleviating the oxidative damage caused by the salinity stress. These results suggested that MT could further promote the accumulation of lipid in microalgae under salinity stress by upregulating lipogenic genes and regulating oxidative stress, which provides a novel strategy for the synthesis of lipid in microalgae.
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2021, Vol. 47 
