Soil fungi underlie a phylogenetic pattern in plant growth responses to nitrogen enrichment
Soil fungi underlie a phylogenetic pattern in plant growth responses to nitrogen enrichment
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DOI：
10.1111/1365-2745.12983
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发表时间：
2018-11
影响因子：
5.5
通讯作者：
Rachel Wooliver;John K. Senior;B. Potts;Michael E. Van Nuland;J. Bailey;J. Schweitzer
中科院分区：
文献类型：
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作者：
Rachel Wooliver;John K. Senior;B. Potts;Michael E. Van Nuland;J. Bailey;J. Schweitzer
在人为氮（N）沉降增加的情况下，一些植物物种会繁衍生息，而另一些则不会。先前的工作表明，植物系统发育可以预测这些反应，并且与菌根真菌的相互作用是驱动植物对氮富集反应变化的机制。然而，这项工作大部分忽略了其他根相关真菌和整个土壤真菌群落在驱动这些反应中的作用。我们通过实施温室实验来测试土壤真菌是否介导植物生长和植物-土壤反馈（近缘植物和远缘植物之间）对氮富集的反应，在该实验中，我们对15种桉树树种进行了氮肥施肥、宿主特异性土壤接种和杀菌剂的因子处理，这些树种共同出现在澳大利亚塔斯马尼亚岛州，并在该亚属内形成了两个系统发育谱系 交香桃属。同种条件土壤真菌增强了一个谱系（谱系 1）内植物对氮富集的生长反应，但抑制了另一谱系（谱系 2）内植物对氮富集的生长响应。外生菌根 (ECM) 定植的谱系特异性变化与之前的证据一致，即在氮富集下更成功的策略和不太成功的策略分别是减少和维持菌根真菌的碳分配。后者还伴随着在氮富集下非丝状真菌（功能未知）的根部定殖的强烈减少。植物-土壤反馈对于谱系 1 是中性的，但对于谱系 2 是负的（即，在相反与相同谱系个体条件下的土壤中生长更快），但不因氮富集或杀菌剂而改变。根定殖的谱系水平差异表明，这些反馈可能是由植物对深色有隔内生菌和非丝状真菌的不同反应性驱动的，其定植似乎有利于植物生长。综合：我们的结果证实，与土壤真菌（特别是 ECM 真菌）的相互作用是树种对氮富集生长反应的系统发育模式的基础，因此可能会影响植物在未来氮沉积情景下的获胜或损失。然而，我们提供了一些初步证据（尽管来自受控条件而不是自然条件），表明氮沉降可能不会在改变植物-土壤反馈方面发挥重要作用。
Under increasing anthropogenic nitrogen (N) deposition, some plant species will thrive while others will not. Previous work has shown that plant phylogeny can predict these responses, and that interactions with mycorrhizal fungi are a mechanism that drives variation in plant responses to N enrichment. Yet, much of this work has ignored the roles of other root‐associated fungi and whole soil fungal communities in driving these responses. We tested whether soil fungi mediate responses of plant growth and plant–soil feedbacks (between close and distant plant relatives) to N enrichment by implementing a greenhouse experiment in which we applied factorial treatments of N fertilization, host‐specific soil inocula and fungicide to 15 eucalypt tree species that co‐occur on the island state of Tasmania, Australia, and form two phylogenetic lineages within the subgenus Symphyomyrtus. Conspecific‐conditioned soil fungi enhanced growth responses to N enrichment for plants within one lineage (lineage 1) but depressed growth responses to N enrichment for plants within another lineage (lineage 2). Lineage‐specific shifts in ectomycorrhizal (ECM) colonization were consistent with previous evidence that more vs. less successful strategies under N enrichment are those where carbon allocation to mycorrhizal fungi is reduced vs. maintained, respectively. The latter was also accompanied by a stronger reduction in root colonization of non‐filamentous fungi (of unknown function) under N enrichment. Plant–soil feedbacks were neutral for lineage 1 but negative for lineage 2 (i.e. greater growth in soils conditioned by opposite vs. same lineage individuals), but were not altered by N enrichment or fungicide. Lineage‐level differences in root colonization suggest that these feedbacks could be driven by differential plant responsiveness to dark septate endophytes and non‐filamentous fungi, the colonization of which seemed to benefit plant growth. Synthesis: Our results confirm that interactions with soil fungi (ECM fungi, in particular) underlie phylogenetic patterns in tree species' growth responses to N enrichment and may, thus, influence which plants win or lose under future N deposition scenarios. Yet, we provide some of the first evidence (albeit from controlled rather than natural conditions) that N deposition may not play a strong role in shifting plant–soil feedbacks.