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General Session 3: Biological oceanography & global change |
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Transcriptomic and microRNAomic profiling reveals multi-faceted mechanisms of coping with phosphate stress in a dinoflagellate
GS3-48
Xinguo Shi, State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences
Xin Lin, State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences
Ling Li, State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences
Meizhen Li, State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences
Brian Palenik, Scripps Institution of Oceanography, University of California
Senjie Lin* , State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences
Presenter Email: senjie.lin@uconn.edu
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| While gene regulation can occur at both transcriptional and epigenetic (microRNA) levels, combined transcriptomic and miRNAomic responses to environmental stress is unexplored for marine plankton. Here, we conducted transcriptome and microRNAome sequencing for the dinoflagellate Prorocentrum donghaiense grown under P-replete and P-depleted conditions to understand molecular mechanisms by which this dinoflagellate copes with P-deficiency. Transcriptomic analysis revealed 1230 unigenes that were differentially expressed with ≥ 2-fold change. Among genes up-regulated under P-depleted condition were those related to DOP hydrolysis, cell cycle regulation, carbon fixation, nitrate assimilation, glycolysis and cellular motor. The identification of high and low affinity phosphate transporters indicates a tunable phosphate uptake strategy. The up-regulation of ATP-acquisition and metabolism genes indicated accelerated recycling under P-deficiency. Various phosphatases such as 5′-Nucleotidase, alkaline phosphatase and serine/threonine phosphatase were actively expressed to facilitate P scavenging. Furthermore, miRNAome sequencing revealed 18 microRNAs, which presumably regulate 8228 protein-coding genes identified in the transcriptome. Among these 4 were down- and 11 up-regulated under P-deficiency; functional enrichment analysis of their target genes predicted decreases in sulfolipid sulfatide metabolism under P-deficiency, which was corroborated by the enrichment of sulfolipid sulfatide detected by liquid chromatography–mass spectrometry (LC-MS) analysis. Also post-transcriptionally up-regulated was proton-pump rhodopsin, suggesting that this proton-pump might be up-tuned to enhance cell survival under P-deficiency. Taken together, our data show that enhanced DOP utilization, accelerated recycle of ATP and repressed sulfolipids degradation through transcriptional and miRNA-mediated post-transcriptional regulations, constitute a comprehensive strategy to cope with P deficiency in a dinoflagellate such as P. donghaiense. |
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