Yannarell Anthony C, Busby Ryan R, Denight Michael L, Gebhart Dick L, Taylor Steven J
Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Front Microbiol. 2011 Jun 3;2:127. doi: 10.3389/fmicb.2011.00127. eCollection 2011.
The spatial scale on which microbial communities respond to plant invasions may provide important clues as to the nature of potential invader-microbe interactions. Lespedeza cuneata (Dum. Cours.) G. Don is an invasive legume that may benefit from associations with mycorrhizal fungi; however, it has also been suggested that the plant is allelopathic and may alter the soil chemistry of invaded sites through secondary metabolites in its root exudates or litter. Thus, L. cuneata invasion may interact with soil microorganisms on a variety of scales. We investigated L. cuneata-related changes to soil bacterial and fungal communities at two spatial scales using multiple sites from across its invaded N. American range. Using whole-community DNA fingerprinting, we characterized microbial community variation at the scale of entire invaded sites and at the scale of individual plants. Based on permutational multivariate analysis of variance, soil bacterial communities in heavily invaded sites were significantly different from those of uninvaded sites, but bacteria did not show any evidence of responding at very local scales around individual plants. In contrast, soil fungi did not change significantly at the scale of entire sites, but there were significant differences between fungal communities of native versus exotic plants within particular sites. The differential scaling of bacterial and fungal responses indicates that L. cuneata interacts differently with soil bacteria and soil fungi, and these microorganisms may play very different roles in the invasion process of this plant.
微生物群落对植物入侵做出响应的空间尺度，可能为潜在的入侵者与微生物相互作用的本质提供重要线索。楔叶胡枝子（Lespedeza cuneata (Dum. Cours.) G. Don）是一种入侵性豆科植物，可能受益于与菌根真菌的共生关系；然而，也有人提出这种植物具有化感作用，可能通过其根系分泌物或凋落物中的次生代谢产物改变入侵地的土壤化学性质。因此，楔叶胡枝子的入侵可能在多种尺度上与土壤微生物相互作用。我们利用来自其入侵的北美范围内的多个地点，在两个空间尺度上研究了与楔叶胡枝子相关的土壤细菌和真菌群落变化。通过全群落DNA指纹图谱，我们在整个入侵地点的尺度和单个植物的尺度上对微生物群落变异进行了表征。基于置换多变量方差分析，重度入侵地点的土壤细菌群落与未入侵地点的显著不同，但细菌在单个植物周围的非常局部的尺度上没有表现出任何响应的迹象。相比之下，在整个地点的尺度上土壤真菌没有显著变化，但在特定地点内本地植物与外来植物的真菌群落之间存在显著差异。细菌和真菌响应的不同尺度表明，楔叶胡枝子与土壤细菌和土壤真菌的相互作用不同，并且这些微生物在这种植物的入侵过程中可能发挥非常不同的作用。
