【Institution】: Xiamen University, China

Abstract

Prorocentrum donghaiense is a bloom-forming thecate dinoflagellate species. It forms massive blooms in the East China Sea coastal waters almost every year since 1998. This species usually prone to form blooms in low P environments. We conducted transcriptome and microRNAome sequencing for P. donghaiense to understand the molecular mechanisms by which this dinoflagellate copes with phosphorus (P) deficiency. Under P-depleted conditions, G1/S specific cyclin gene was markedly down-regulated, consistent with growth inhibition, and genes related to dissolved organic phosphorus (DOP) hydrolysis, carbon fixation, nitrate assimilation, glycolysis, and cellular motility were up-regulated. The elevated expression of ATP-generating genes (for example, rhodopsin) and ATP-consuming genes suggests some metabolic reconfiguration towards accelerated ATP recycling under P deficiency. The decreased sulfatide (sulfolipid) was identified using both in post-transcriptome and HPLC-MS analysis. Taken together, our result showed that enhanced DOP utilization, accelerated ATP cycling and repressed sulfolipid degradation constitute a comprehensive strategy to cope with P deficiency in a model dinoflagellate. Based on the transcriptome data sheet, we isolated growth and biomass accumulation related gene G1/S cyclin, cellulose synthase and cellulase encoding genes in dinoflagellate P. donghaiense. The expression profiles of the three genes throughout the cell cycle were also been detected. The results suggest that G1/S cyclin, cellulase, and cellulose synthase genes associated with G1/S transition, G2M, and G1 phases of the cell cycle and are candidates of biomarkers for assessing growth status of P. donghaiense.