Proteome response of Dunaliella parva induced by nitrogen limitation

Nitrogen limitation is the most widely used method for directing metabolic flux to lipid biosynthesis in microalgae. Protein level changes induced by environmental stress could be investigated by proteomics analysis, which was a favourable approach for understanding the induction mechanisms. Although, we previously provided the results of transcriptome sequencing of Dunaliella parva under nitrogen limitation stress, the effects of nitrogen limitation on the microalgal proteome were not reported. The impact of nitrogen limitation on the proteome of green alga D. parva was investigated using iTRAQ quantitative proteomics technique. A total of 227 proteins were up-regulated, and 159 proteins were down-regulated under the nitrogen limitation condition. Functional analyses of differentially expressed proteins revealed that nitrogen limitation could induce protein level changes related to photosynthesis, stress response, lipid metabolism, carbohydrate metabolism and nitrogen metabolism. This study, together with our previous transcriptome sequencing of D. parva, therefore provides a foundation for understanding the regulatory mechanism of lipid biosynthesis induced by nitrogen limitation, which could further guide the genetic modification of lipid accumulation in D. parva.