Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden.
Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria.
Environ Microbiol. 2021 Apr;23(4):2199-2214. doi: 10.1111/1462-2920.15392. Epub 2021 Jan 21.
While the environment is considered the primary origin of the plant microbiome, the potential role of seeds as a source of transmitting microorganisms has not received much attention. Here we tested the hypothesis that the plant microbiome is partially inherited through vertical transmission. An experimental culturing device was constructed to grow oak seedlings in a microbe-free environment while keeping belowground and aboveground tissues separated. The microbial communities associated with the acorn's embryo and pericarp and the developing seeding's phyllosphere and root systems were analysed using amplicon sequencing of fungal ITS and bacterial 16S rDNA. Results showed that the seed microbiome is diverse and non-randomly distributed within an acorn. The microbial composition of the phyllosphere was diverse and strongly resembled the composition found in the embryo, whereas the roots and pericarp each had a less diverse and distinct microbial community. Our findings demonstrate a high level of microbial diversity and spatial partitioning of the fungal and bacterial community within both seed and seedling, indicating inheritance, niche differentiation and divergent transmission routes for the establishment of root and phyllosphere communities.
虽然环境被认为是植物微生物组的主要起源，但种子作为传播微生物源的潜在作用尚未得到太多关注。在这里，我们检验了植物微生物组通过垂直传播部分遗传的假说。我们构建了一个实验培养装置，在无菌环境中培育橡树幼苗，同时将地下和地上组织分开。使用真菌 ITS 和细菌 16S rDNA 的扩增子测序分析了与橡子胚和种皮以及发育中的种子叶际和根系相关的微生物群落。结果表明，种子微生物组在橡子内是多样的且非随机分布的。叶际的微生物组成多样，与在胚胎中发现的组成非常相似，而根和种皮各有一个较少多样且独特的微生物群落。我们的发现表明，在种子和幼苗内，真菌和细菌群落具有高度的微生物多样性和空间分隔，表明了根和叶际群落的建立存在遗传、生态位分化和不同的传播途径。
