Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; Jiangsu Marine Resources Development Research Institute, Lianyungang 222005, China; CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China.
Harmful Algae. 2022 Aug;117:102267. doi: 10.1016/j.hal.2022.102267. Epub 2022 Jun 2.
Phosphorus (P) is one of the major macronutrients necessary for phytoplankton growth. In some parts of the ocean, however, P is frequently scarce, hence, there is limited phytoplankton growth. To cope with P deficiency, phytoplankton evolved a variety of strategies, including, utilization of different P sources. Polyphosphate (polyP) is ubiquitously present and serves an essential function in aquatic environments, but it is unclear if and how this polymer is utilized by phytoplankton. Here, we examined the physiological and molecular responses of the widely present harmful algal bloom (HAB) species, Heterosigma akashiwo in polyP utilization, and in coping with P-deficiency. Our results revealed that two forms of inorganic polyP, namely, sodium tripolyphosphate and sodium hexametaphosphate, support H. akashiwo growth as efficiently as orthophosphate. However, few genes involved in polyP utilization have been identified. Under P-deficient conditions, genes associated with P transport, dissolved organic P utilization, sulfolipid synthesis, and energy production, were markedly elevated. In summary, our results indicate that polyP is bioavailable to H. akashiwo, and this HAB species have evolved a comprehensive strategy to cope with P deficiency.
磷（P）是浮游植物生长所必需的主要大量营养素之一。然而，在海洋的某些区域，P 经常匮乏，因此，浮游植物的生长受到限制。为了应对 P 缺乏，浮游植物进化出了多种策略，包括利用不同的 P 源。多聚磷酸盐（polyP）广泛存在，在水生环境中发挥着重要作用，但目前尚不清楚浮游植物是否以及如何利用这种聚合物。在这里，我们研究了广泛存在的有害藻类水华（HAB）物种，膝沟藻属（Heterosigma akashiwo）在多聚磷酸盐利用和应对 P 缺乏方面的生理和分子反应。我们的结果表明，两种形式的无机多聚磷酸盐，即三聚磷酸钠和六偏磷酸钠，能够像正磷酸盐一样有效地支持膝沟藻属的生长。然而，目前已经鉴定出的参与多聚磷酸盐利用的基因很少。在 P 缺乏条件下，与 P 转运、溶解有机 P 利用、硫脂合成和能量产生相关的基因显著上调。总之，我们的结果表明，多聚磷酸盐对膝沟藻属是可利用的，并且这种赤潮物种已经进化出了一种全面的策略来应对 P 缺乏。
