营养竞争作为光合共生中调控的一般机制
Nutrient Competition as a General Mechanism of Regulation in Photosymbiosis
- HIFMB, Helmholtz Institute for Functional Marine Biodiversity, Oldenburg, Germany（赫尔姆霍兹功能海洋生物多样性研究所）
- University of Oldenburg, Institute for Chemistry and Biology of the Marine Environment, Oldenburg, Germany（奥尔登堡大学海洋环境化学与生物学研究所）
- Alfred-Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany（阿尔弗雷德·韦格纳极地海洋研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过广义建模揭示氮限制通过种内与种间竞争相互作用稳定光合共生，并随宿主氮同化增强转向种间竞争主导。
AI中文摘要：
氮限制是调节光合共生刺胞动物与其藻类共生体之间互利共生关系的关键机制。藻类来源的光合产物促进宿主对无机氮（特别是铵）的同化。共生伙伴之间对无机氮的竞争导致一个负反馈循环，其中共生体密度通过促进其竞争者而得到有效控制。然而，尚不清楚在没有其他形式调控的情况下，这一反馈循环是否足以稳定这种相互作用。利用广义建模方法，我们确定了刺胞动物-藻类对氮的竞争产生动态稳定共生的条件。我们表明，通过种内（共生体-共生体）和种间（宿主-共生体）竞争的相互作用，氮限制足以稳定这种相互作用。随着宿主对无机氮同化作用的增强，系统从由共生体之间的种内竞争稳定转变为由宿主与共生体之间的种间竞争稳定，这要求共生体密度通过光合产物转运与宿主氮同化正耦合，以实现动态稳定性。
英文摘要：
Nitrogen limitation is a key mechanism regulating the mutualism between photosymbiotic cnidarians and their algal symbionts. Algal-derived photosynthate facilitates host assimilation of inorganic nitrogen, specifically ammonium. The resulting competition between symbiotic partners for inorganic nitrogen leads to a negative feedback loop wherein symbiont density is effectively controlled through facilitation of their competitor. However, it is unclear whether this feedback loop is sufficient to stabilize the interaction absent other forms of regulation. Using a generalized modeling approach, we identify the conditions under which cnidarian-algal competition for nitrogen yields dynamically stable symbioses. We show that nitrogen limitation is sufficient to stabilize the interaction through the interplay of intraspecific (symbiont-symbiont) and interspecific (host-symbiont) competition. As host assimilation of inorganic nitrogen increases, the system shifts from being stabilized by intraspecific competition between symbionts to interspecific competition between host and symbionts, necessitating a positive coupling of symbiont density to host nitrogen assimilation via photosynthate translocation for dynamic stability.
