Common mycorrhizal networks (CMNs) can link multiple plants and distribute nutrients among them. However, how parasitic plants regulate the carbon and nutrient exchange between CMNs and the linked plants is unknown. Thus, we conducted a container experiment with two Trifolium pratense grown in two plastic cores and connected only by CMNs using a 25‐μm nylon fabric in each container. Host T. pratense was parasitized or not parasitized by Cuscuta gronovii. CMNs were left intact or broken by rotating the cores with the host or neighboring T. pratense. The dual 15N and 13C labeling method was used to evaluate the N distributed by CMNs to the host and neighboring T. pratense and the recently fixed C from the host and neighboring T. pratense to CMNs. The results showed that CMNs distributed more 15N to unparasitized neighboring T. pratense than the parasitized host T. pratense. Moreover, the unparasitized neighboring T. pratense provides more recently fixed C to CMNs than the parasitized host T. pratense. These results revealed that the parasite regulated C and nutrient exchange between CMNs and the linked plants following the reciprocal rewards rule. Moreover, this study highlights the importance of parasitic plants in the regulation of mutualistic interactions in ecological webs.

中文翻译：

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寄生植物调节连接寄主和邻近植物的常见菌根网络中的碳和氮分布


常见菌根网络（CMN）可以连接多种植物并在它们之间分配养分。然而，寄生植物如何调节 CMN 和相关植物之间的碳和养分交换尚不清楚。因此，我们进行了一个容器实验，其中两个红三叶草生长在两个塑料芯中，并且仅通过 CMN 连接，每个容器中使用 25 μm 尼龙织物。宿主草菟丝子寄生或不寄生菟丝子。通过将核心与宿主或邻近的 T. pratense 一起旋转，CMN 可以保持完整或被破坏。采用 15N 和 13C 双标记方法评估 CMN 分配给宿主和邻近的 T. pratense 的 N 以及最近从宿主和邻近的 T. pratense 向 CMN 固定的 C。结果表明，CMNs向未寄生的邻近T. pratense分配的15N比被寄生的宿主T. pratense更多。此外，未寄生的邻近 T. pratense 比寄生的宿主 T. pratense 为 CMN 提供了更多最近固定的 C。这些结果表明，寄生虫按照互惠奖励规则调节 CMN 和相关植物之间的碳和养分交换。此外，这项研究强调了寄生植物在调节生态网络互利相互作用中的重要性。