State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen 361005, China; CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
BGI-Shenzhen, Beishan Industrial Zone 11(th) Building, Yantian District, Shenzhen, Guangdong 518083, China.
Sci Total Environ. 2021 May 10;768:144515. doi: 10.1016/j.scitotenv.2020.144515. Epub 2021 Jan 7.
Dinoflagellate blooming periods are paradoxically characterized by high biomass growth rate and low ambient dissolved CO and inorganic nutrients, however, the underlying mechanisms linking cell growth and nutrient acquisition are poorly understood. Here, we compared metaproteomes of non-bloom, mid-blooming and late-blooming cells of a marine dinoflagellate Prorocentrum donghaiense. Cell division, metabolism of carbon, nitrogen, phosphorus, lipid, porphyrin and chlorophyll were more active in blooming cells than in non-bloom cells. Up-regulation of carbonic anhydrase, ribulose-1,5-bisphosphate carboxylase/oxygenase II, and C-cycle proteins enhanced CO assimilation of P. donghaiense. Proteins participating in external organic nutrient acquisition and conversion, such as transporters for fatty acids, peptides and amino acids, external- and internal-phosphomonoester hydrolase, and diverse peptidases and amino acid transaminases, exhibited higher expression in blooming cells relative to non-bloom cells. Interestingly, dissolved organic nitrogen (DON) such as urea and aspartate significantly down-regulated expression and activity of carbon assimilation proteins except for RuBisCO form II, suggesting that DON provided sufficient carbon source which reduced the need to concentrate internal CO. This study demonstrates that coupling of efficient CO assimilation with DON utilization are essential for bloom maintenance of P. donghaiense, and future efforts should be devoted to dissolved organic nutrients for prevention and management of dinoflagelllate blooms.
甲藻赤潮期的特征是生物量增长率高和环境溶解 CO 和无机养分低，但细胞生长和养分获取之间的联系的潜在机制仍知之甚少。在这里，我们比较了海洋甲藻东海原甲藻的非赤潮期、赤潮中期和赤潮后期细胞的宏蛋白质组。与非赤潮细胞相比，细胞分裂、碳、氮、磷、脂质、卟啉和叶绿素的代谢在赤潮细胞中更为活跃。碳酸酐酶、核酮糖-1,5-二磷酸羧化酶/加氧酶 II 和 C 循环蛋白的上调增强了东海原甲藻的 CO 同化。参与外部有机营养物质获取和转化的蛋白质，如脂肪酸、肽和氨基酸的转运蛋白、外部和内部磷酸单酯水解酶以及多种肽酶和氨基酸转氨酶，在赤潮细胞中的表达相对高于非赤潮细胞。有趣的是，溶解有机氮（DON）如尿素和天冬氨酸显著下调了除 RuBisCO 形式 II 之外的碳同化蛋白的表达和活性，表明 DON 提供了足够的碳源，减少了对内部 CO 的集中需求。本研究表明，高效 CO 同化与 DON 利用的耦合对于东海原甲藻赤潮的维持至关重要，未来应致力于溶解有机营养物质，以预防和管理甲藻赤潮。
