Elevated atmospheric CO2 enhances grazer-induced morphological defense in the freshwater green alga Scenedesmus obliquus
Elevated atmospheric CO2 enhances grazer-induced morphological defense in the freshwater green alga Scenedesmus obliquus
复制标题
大气中二氧化碳含量升高增强了淡水绿藻斜生栅藻中食草动物诱导的形态防御
DOI：
10.1002/lno.10715
复制
发表时间：
2018-03-01
影响因子：
4.5
通讯作者：
Yang, Zhou
中科院分区：
文献类型：
--
作者：
Huang, Yuan;Cui, Guilian;Yang, Zhou
大气中的二氧化碳含量正在增加，并对水生生态系统产生重大影响。食草动物诱导的浮游植物防御稳定了水生食物网的结构。与防御相关的成本导致了诱导防御的有效性取决于环境条件的情况。为了研究食草动物诱导的防御反应升高的空气中的CO2水平，藻类栅列藻培养下的两个空气中的CO2浓度（390 ppm和750 ppm）的情况下或存在的捕食者衍生的线索（水蚤滤液）。在水蚤滤液的作用下，S.阿古斯当空气CO2浓度升高到750 ppm时，培养基中的无机碳含量增加，从而刺激藻类繁殖和光合作用。此外，在升高的CO2条件下，单细胞和双细胞集落的体积增大。这些生理变化满足了形成更大菌落的物质和能量需求。基于大菌落在环境和升高的CO2条件下单位体积的一致表面积，增加的无机碳（通过CO2富集）促进了多细胞菌落的碳吸收。因此，在浮游植物的形态防御增强与更多的八细胞菌落形成的人口在高CO2环境中生长。目前的结果验证了诱导防御的假设，即成本较低，并具有较高的效率与碳的可用性增加。浮游植物中抗食草动物形态防御的增强可能会改变浮游植物和浮游动物之间的营养级联，并有助于在CO2上升气候下生态系统水平过程中重新定向能量和营养流。研究了栅藻对CO2浓度升高的诱导防御作用，结果表明，CO2浓度升高使藻体中的无机碳含量增加，促进了藻体中大量的无机碳的形成，并使藻体中的无机碳含量增加，从而使藻体中的无机碳含量增加，并使藻体中的无机碳含量增加。高浓度CO2使单细胞和双细胞的浮游植物群体的体积增大，增强了食草动物诱导的浮游植物形态防御。
Atmospheric CO2 level is increasing and considerably influences aquatic ecosystems. Grazer-induced defenses in phytoplankton stabilize the structures of aquatic food webs. Costs associated with defense have resulted in a situation in which the effectiveness of inducible defenses depends on environmental conditions. To investigate the grazer-induced defense responses to elevated air CO2 levels, the algae Scenedesmus obliquus was cultured under two air CO2 concentrations (390 ppm and 750 ppm) in the absence or presence of predator-derived cues (Daphnia filtrate). In response to Daphnia filtrate, colonial populations such as eight-celled colony were largely formed in S. obliquus. When air CO2 was elevated to 750 ppm, the inorganic carbon contents in media increased, thereby stimulating algal reproduction and photosynthesis. Moreover, the volumes of unicells and two-celled colonies were enlarged under elevated CO2 conditions. These physiological changes satisfied the material and energy demands for the formation of larger colonies. Based on the consistent surface area per volume of the large colony under ambient and elevated CO2 conditions, the increased inorganic carbon (by CO2 enrichment) facilitated the carbon uptake of the multi-celled colony. Thus, the morphological defense in phytoplankton was enhanced with more eight-celled colonies formed in populations grown in a high-CO2 environment. The present result verified the hypothesis that inducible defense is less costly and has higher effectiveness with increasing carbon availability. The enhancement of anti-grazer morphological defenses in phytoplankton potentially alters the trophic cascades between phytoplankton and zooplankton and contributes to the redirected energy and nutrient flow in ecosystem-level processes under a CO2-rising climate.HighlightsResponse of grazer-induced defense in Scenedesmus to elevated CO2 was studied.Elevated CO2 increased inorganic carbon in media with stimulated algal growth.Elevated CO2 promoted formation of more large colonies in response to predation.Volumes of unicells and two-celled colonies were enlarged by high CO2.Elevated CO2 enhanced grazer-induced morphological defense in phytoplankton.