PDF(Pubmed)
Abstract：
BACKGROUND: Fungi and bacteria coexist in a wide variety of environments, and their interactions are now recognized as the norm in most agroecosystems. These microbial communities harbor keystone taxa, which facilitate connectivity between fungal and bacterial communities, influencing their composition and functions. The roots of most plants are associated with arbuscular mycorrhizal (AM) fungi, which develop dense networks of hyphae in the soil. The surface of these hyphae (called the hyphosphere) is the region where multiple interactions with microbial communities can occur, e.g., exchanging or responding to each other\'s metabolites. However, the presence and importance of keystone taxa in the AM fungal hyphosphere remain largely unknown.
RESULTS: Here, we used in vitro and pot cultivation systems of AM fungi to investigate whether certain keystone bacteria were able to shape the microbial communities growing in the hyphosphere and potentially improved the fitness of the AM fungal host. Based on various AM fungi, soil leachates, and synthetic microbial communities, we found that under organic phosphorus (P) conditions, AM fungi could selectively recruit bacteria that enhanced their P nutrition and competed with less P-mobilizing bacteria. Specifically, we observed a privileged interaction between the isolate Streptomyces sp. D1 and AM fungi of the genus Rhizophagus, where (1) the carbon compounds exuded by the fungus were acquired by the bacterium which could mineralize organic P and (2) the in vitro culturable bacterial community residing on the surface of hyphae was in part regulated by Streptomyces sp. D1, primarily by inhibiting the bacteria with weak P-mineralizing ability, thereby enhancing AM fungi to acquire P.
CONCLUSIONS: This work highlights the multi-functionality of the keystone bacteria Streptomyces sp. D1 in fungal-bacteria and bacterial-bacterial interactions at the hyphal surface of AM fungi. Video Abstract.
RESULTS: Here, we used in vitro and pot cultivation systems of AM fungi to investigate whether certain keystone bacteria were able to shape the microbial communities growing in the hyphosphere and potentially improved the fitness of the AM fungal host. Based on various AM fungi, soil leachates, and synthetic microbial communities, we found that under organic phosphorus (P) conditions, AM fungi could selectively recruit bacteria that enhanced their P nutrition and competed with less P-mobilizing bacteria. Specifically, we observed a privileged interaction between the isolate Streptomyces sp. D1 and AM fungi of the genus Rhizophagus, where (1) the carbon compounds exuded by the fungus were acquired by the bacterium which could mineralize organic P and (2) the in vitro culturable bacterial community residing on the surface of hyphae was in part regulated by Streptomyces sp. D1, primarily by inhibiting the bacteria with weak P-mineralizing ability, thereby enhancing AM fungi to acquire P.
CONCLUSIONS: This work highlights the multi-functionality of the keystone bacteria Streptomyces sp. D1 in fungal-bacteria and bacterial-bacterial interactions at the hyphal surface of AM fungi. Video Abstract.
摘要：
背景：真菌和细菌在各种各样的环境中共存，它们的相互作用现在被认为是大多数农业生态系统的常态。这些微生物群落拥有基石类群，促进真菌和细菌群落之间的联系，影响它们的组成和功能。大多数植物的根与丛枝菌根（AM）真菌有关，在土壤中形成密集的菌丝网络。这些菌丝的表面（称为hyphosphhere）是与微生物群落可能发生多种相互作用的区域，例如，交换或响应彼此的代谢物。然而,AM真菌磷酸化中梯形分类群的存在和重要性仍然未知。
结果：这里，我们使用AM真菌的体外和盆栽培养系统来研究某些梯形细菌是否能够塑造在hyphosphhere中生长的微生物群落，并可能改善AM真菌宿主的适应性。基于各种AM真菌，土壤渗滤液，和合成微生物群落，我们发现在有机磷(P)条件下，AM真菌可以选择性地招募细菌，从而增强其P营养并与较少的P动员细菌竞争。具体来说,我们观察到分离链霉菌sp之间的特权相互作用。根虫属的D1和AM真菌，其中（1）真菌渗出的碳化合物是由可以使有机P矿化的细菌获得的；（2）位于菌丝表面的体外可培养细菌群落部分受到链霉菌属的调节。D1，主要通过抑制具有弱P矿化能力的细菌，从而增强AM真菌以获得P。
结论：这项工作强调了梯形细菌链霉菌的多功能性。AM真菌菌丝表面真菌-细菌和细菌-细菌相互作用中的D1。视频摘要。
结果：这里，我们使用AM真菌的体外和盆栽培养系统来研究某些梯形细菌是否能够塑造在hyphosphhere中生长的微生物群落，并可能改善AM真菌宿主的适应性。基于各种AM真菌，土壤渗滤液，和合成微生物群落，我们发现在有机磷(P)条件下，AM真菌可以选择性地招募细菌，从而增强其P营养并与较少的P动员细菌竞争。具体来说,我们观察到分离链霉菌sp之间的特权相互作用。根虫属的D1和AM真菌，其中（1）真菌渗出的碳化合物是由可以使有机P矿化的细菌获得的；（2）位于菌丝表面的体外可培养细菌群落部分受到链霉菌属的调节。D1，主要通过抑制具有弱P矿化能力的细菌，从而增强AM真菌以获得P。
结论：这项工作强调了梯形细菌链霉菌的多功能性。AM真菌菌丝表面真菌-细菌和细菌-细菌相互作用中的D1。视频摘要。
