Consequences of simultaneous interactions of fungal endophytes and arbuscular mycorrhizal fungi with a shared host grass
Consequences of simultaneous interactions of fungal endophytes and arbuscular mycorrhizal fungi with a shared host grass
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DOI：
10.1111/j.1600-0706.2012.20153.x
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发表时间：
2012-12-01
期刊：
影响因子：
3.4
通讯作者：
Clay, Keith
中科院分区：
文献类型：
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作者：
Larimer, Anna L.;Bever, James D.;Clay, Keith
植物在其一生中同时与多种微生物共生体相关联。为了解决同时共生体的影响是否取决于具体身份的问题，我们进行了一项温室实验，操纵丛枝菌根真菌（AMF）和真菌内生菌在共享宿主草披碱草上的存在和身份。每个植物宿主都接种了两种对宿主生长有不同影响的 AMF 物种之一，或无菌土壤对照。此外，我们使用了来自两个内生菌Epichloe elymi种群的天然存在的内生菌感染（E+）和未感染（E）个体，它们与E. hystrix的相互作用有所不同。然后我们测量了植物、AMF 和内生真菌的反应。总体而言，我们发现 AMF 和真菌内生菌对植物生长的综合影响是相加的，反映了每个共生体独立与宿主植物相互作用的共生质量。然而，内生真菌感染不同程度地改变了两种 AMF 物种的菌丝定殖，并且同时感染的 AMF 物种的身份影响了内生真菌的适应性特征。这项研究的结果表明，种间共生相互作用的结果随伙伴身份的不同而变化，因此同时共生的影响不能一概而论。
Plants simultaneously associate with multiple microbial symbionts throughout their lifetimes. To address the question of whether the effects of simultaneous symbionts are contingent on the specific identities, we conducted a greenhouse experiment manipulating the presence and identities of arbuscular mycorrhizal fungi (AMF) and fungal endophytes on the shared host grass Elymus hystrix. Each plant host was inoculated with one of two AMF species having varying effects on host growth, or a sterile soil control. Further, we used naturally occurring endophyte-infected (E+) and uninfected (E) individuals from two populations of the endophyte Epichloe elymi that varied in their interaction with E. hystrix. We then measured responses of plants, AMF, and fungal endophytes. Overall, we found that the combined effects of AMF and fungal endophytes on plant growth were additive, reflecting the mutualistic quality of each symbiont independently interacting with host plants. However, fungal endophyte infection differentially altered hyphal colonization of the two AMF species and the identity of the coinfecting AMF species affected fungal endophyte fitness traits. The results of this study demonstrate that the outcome of interspecific symbiotic interactions varies with partner identity such that the effects of simultaneous symbioses can not be generalized.