Does Epichloe Endophyte Enhance Host Tolerance to Root Hemiparasite?
Does Epichloe Endophyte Enhance Host Tolerance to Root Hemiparasite?
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Epichloê内生菌是否增强宿主对根半寄生生物的耐受性？
DOI：
10.1007/s00248-020-01496-8
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发表时间：
2020-02-21
影响因子：
3.6
通讯作者：
Li, Chunjie
中科院分区：
文献类型：
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作者：
Bao, Gensheng;Son, Meiling;Li, Chunjie
在大多数环境条件下，表生内生菌已被证明是冷季型草的互利共生体。虽然半寄生物和它们的宿主之间的成对相互作用受到宿主相关的共生微生物的严重影响，但在研究寄生植物对宿主性能的影响时，很少注意微生物-植物相互作用的影响，特别是内生共生。在这项研究中，我们进行了一个温室实验，以研究遗传Epichelium内生菌共生的影响，在存在或不存在的兼性根半寄生（甘肃马先蒿）的两个主机草（针茅purpurea和唐古特）的生长。我们观察到的寄生两个主机由P. kansuensis：当生长与宿主植物，半寄生降低主机的性能，同时提高自己的生物量和存活率的半寄生。寄生内生菌感染的S.紫花苜蓿植株的生物量、分蘖数、根冠比和光合参数均高于不含内生菌的紫花苜蓿，而功能吸器的数量低于不含内生菌的紫花苜蓿。紫菀与此相反，被寄生的内生菌感染的E.唐古特具有较低的生物量，根冠比，光合参数和吸器和功能吸器的数量比他们的内生菌的对应物。我们的研究结果表明，内生菌和宿主草之间的相互作用是上下文依赖的，植物-植物的相互作用可以强烈地影响他们的互利互动。内生菌来源于S.紫花苜蓿缓解了甘肃拟单胞菌引起的寄主生物量减少和半寄生虫的生长抑制。这些发现为利用草内生菌共生体作为有效和可持续管理这种杂草半寄生虫的生物防治方法提供了新的思路。
Epichloe endophytes have been shown to be mutualistic symbionts of cool-season grasses under most environmental conditions. Although pairwise interactions between hemiparasites and their hosts are heavily affected by host-associated symbiotic microorganisms, little attention has been paid to the effects of microbe-plant interactions, particularly endophytic symbiosis, in studies examining the effects of parasitic plants on host performance. In this study, we performed a greenhouse experiment to examine the effects of hereditary Epichloe endophyte symbiosis on the growth of two host grasses (Stipa purpurea and Elymus tangutorum) in the presence or absence of a facultative root hemiparasite (Pedicularis kansuensis Maxim). We observed parasitism of both hosts by P. kansuensis: when grown with a host plant, the hemiparasite decreased the performance of the host while improving its own biomass and survival rate of the hemiparasite. Parasitized endophyte-infected S. purpurea plants had higher biomass, tillers, root:shoot ratio, and photosynthetic parameters and a lower number of functional haustoria than the endophyte-free S. purpurea conspecifics. By contrast, parasitized endophyte-infected E. tangutorum had a lower biomass, root:shoot ratio, and photosynthetic parameters and a higher number of haustoria and functional haustoria than their endophyte-free counterparts. Our results reveal that the interactions between the endophytes and the host grasses are context dependent and that plant-plant interactions can strongly affect their mutualistic interactions. Endophytes originating from S. purpurea alleviate the host biomass reduction by P. kansuensis and growth depression in the hemiparasite. These findings shed new light on using grass-endophyte symbionts as biocontrol methods for the effective and sustainable management of this weedy hemiparasite.