Bragina Anastasia, Berg Christian, Müller Henry, Moser Daniel, Berg Gabriele
Graz University of Technology, Environmental Biotechnology, Petersgasse 12, 8010 Graz, Austria.
Sci Rep. 2013;3:1955. doi: 10.1038/srep01955.
Plant-associated bacteria are important for the growth and health of their host, but little is known about its functional diversity and impact on ecosystem functioning. We studied bacterial nitrogen fixation and methane oxidation from indicator Sphagnum mosses in Alpine bogs to test a hypothesis that the plant microbiome contained different functional patterns depending on their functions within the ecosystem. A high abundance and diversity of nitrogenase genes were detected, mostly specific for each Sphagnum. In contrast, methanotrophs formed highly similar patterns despite a high abundance and diversity of methane monooxygenase genes. Our hypothesis was supported by these contrasting functional patterns together with the result that the Sphagnum sporophyte contained a high proportion of specific diazotrophs (45.5%) but no potential methanotrophs. While essential for plant growth under nutrient-limited conditions, nitrogen-fixing bacteria were highly specific and transferred with the sporophyte unlike the ubiquitous methanotrophs which are important for the climate-relevant ecosystem itself.
与植物相关的细菌对其宿主的生长和健康至关重要，但人们对其功能多样性及其对生态系统功能的影响知之甚少。我们研究了高山沼泽中指示性泥炭藓的细菌固氮和甲烷氧化作用，以检验一个假设，即植物微生物群根据其在生态系统中的功能包含不同的功能模式。检测到高丰度和多样性的固氮酶基因，大多对每种泥炭藓具有特异性。相比之下，尽管甲烷单加氧酶基因丰度和多样性很高，但甲烷氧化菌形成了高度相似的模式。这些截然不同的功能模式以及泥炭藓孢子体含有高比例的特定固氮菌（45.5%）但没有潜在甲烷氧化菌的结果支持了我们的假设。虽然固氮细菌在营养有限的条件下对植物生长至关重要，但它们具有高度特异性并与孢子体一起转移，这与对与气候相关的生态系统本身很重要的无处不在的甲烷氧化菌不同。
