The transcriptome of Tetraselmis suecica reveals new insights on green algae response to nitrogen starvation

Nitrogen starvation is an efficient environmental pressure used to increase lipid accumulation and oil droplet formation in microalgal cells. Various studies focused on metabolic changes occurring in microalgae in nitrogen starvation conditions, but the mechanisms at the basis of these changes are not completely understood. Between microalgae, green algae, with more than 7000 species growing in a variety of habitats, have been frequently studied for energy purposes, but also as source of bioactive extracts/compounds. In this study, de novo transcriptome of the green algae Tetraselmis suecica has been performed in order to (1) deeply study its response to nitrogen starvation, (2) to look for enzymes with antioxidant capacity and for polyketide synthases (PKSs), (3) if present, to evaluate if nutrient starvation can influence their expression levels. Tetraselmis suecica was cultured in two conditions, i.e. Nitrogen-starved or -repleted (control) conditions. Cells were harvested at the end of the stationary phase and used for RNA extraction. Triplicate samples of both conditions were sequenced and differential expression analysis was performed. In addition, enzymes with biotechnological interest were identified.