Comparative Transcriptome Analysis Provides Insights into The Response of Ulva Compressa to The Fluctuating Salinity Conditions

Background: Ulva compressa, known as the green tide forming species, was reported that can adapt to hypo-salinity conditions such as estuaries and brackish lakes. To understand the underlying molecular mechanisms of hypo-salinity stress tolerance, a genome-wide gene expression profiles in U. compressa was performed using digital gene expression profile (DGE). Results: The RNA-seq data were analyzed based on the comparison of differently expressed genes involved in specific pathways under hypo-salinity and recovery conditions. Under the long-term hypo-salinity stress, the recovery of photosynthesis and energy metabolism could provide sufficient energy for the tolerance under long-term hypo-saline stress. Multiple strategies were performed to maintain the osmotic homeostasis. Additionally, several long non-coding RNA were detected as differently expressed genes during the stress, which could play important roles in the osmotolerance. Conclusions: Our work will serve as an essential foundation for the understanding of the tolerance mechanism of U. compressa under the fluctuating salinity conditions.