College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Qingdao, 266100, China.
College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
Mar Environ Res. 2024 Nov;202:106753. doi: 10.1016/j.marenvres.2024.106753. Epub 2024 Sep 19.
Phosphorus (P) is an essential nutrient driving algal growth in aquatic ecosystems. Dissolved inorganic and organic P (DIP and DOP) are the main components in the marine P pools and are closely related to harmful algal blooms. The dinoflagellate Akashiwo sanguinea is a cosmopolitan species which frequently causes dense blooms in estuaries and coasts worldwide, while the availability of P to A. sanguinea still remain unclear. Herein, the physiological and transcriptomic responses of A. sanguinea grown under P-deficient, DIP-replete and DOP-replete conditions were compared. P-deficient adversely suppressed the growth and photosynthesis of A. sanguinea, while genes associated with P transport, DOP utilization, sulfolipid synthesis, and energy production, were markedly elevated. Three forms of DOP, namely, glucose-6-phosphate (G-6-P), adenosine 5-triphosphate (ATP), and β-Glycerol phosphate (SG-P), supported A. sanguinea growth as efficiently as DIP (NaHPO), and no significant difference was observed in biochemical compositions and photosynthesis of A. sanguinea between the DIP and DOP treatments. While the genes related to P transporter were markedly suppressed in DOP groups compared with the DIP group. Our results indicated that A. sanguinea is a good growth strategist under P-deficient/replete conditions, and this species had evolved a comprehensive strategy to cope with P deficiency, which might be a crucial factor driving bloom formation in a low inorganic P environment.
磷（P）是驱动水生生态系统中藻类生长的必需营养物质。溶解无机磷（DIP）和溶解有机磷（DOP）是海洋磷库中的主要成分，与有害藻类大量繁殖密切相关。夜光藻（Akashiwo sanguinea）是一种世界性物种，经常在世界范围内的河口和沿海地区引发密集的水华，而夜光藻对 P 的利用情况仍不清楚。本文比较了在 P 缺乏、DIP 充足和 DOP 充足条件下生长的夜光藻的生理和转录组响应。P 缺乏会严重抑制夜光藻的生长和光合作用，而与 P 转运、DOP 利用、硫脂合成和能量产生相关的基因则显著升高。三种形式的 DOP，即葡萄糖-6-磷酸（G-6-P）、三磷酸腺苷（ATP）和β-甘油磷酸（SG-P），能够像 DIP（NaHPO）一样有效地支持夜光藻的生长，并且在 DIP 和 DOP 处理之间，夜光藻的生化组成和光合作用没有明显差异。然而，与 DIP 组相比，DOP 组中与 P 转运体相关的基因显著受到抑制。我们的研究结果表明，在 P 缺乏/充足条件下，夜光藻是一种良好的生长策略，该物种已经进化出一种综合策略来应对 P 缺乏，这可能是在低无机 P 环境中形成水华的关键因素。
