Noble Anya S, Abbaszadeh Jaber, Lee Charles K
School of Science, University of Waikato, Hamilton, New Zealand.
Microbiome. 2025 Jan 31;13(1):35. doi: 10.1186/s40168-024-02000-x.
A growing body of evidence demonstrates that host-associated microbial communities of plant leaf surfaces (i.e. the phyllosphere) can influence host functional traits. However, it remains unclear whether host selection is a universal driver of phyllosphere community assembly. We targeted mānuka (Leptospermum scoparium) and three neighbouring non-mānuka plant species along an 1800-m transect in a New Zealand native bush to conduct a hypothesis-driven investigation of the relative influence of host species identity and stochastic dispersal on the composition of natural phyllosphere bacterial communities.
We detected significant correlations between host species identity and mānuka phyllosphere communities that are consistent with a dominant role of host selection in the assembly of the mānuka phyllosphere microbiome. In contrast, the phyllosphere community compositions of neighbouring, ecologically similar native plants were highly variable, suggesting that stochastic processes, such as dispersal, had a stronger influence on the phyllosphere microbiomes of those non-mānuka plants compared to the phyllosphere microbiome of mānuka. Furthermore, the distribution of phyllosphere taxa among plant species was congruent with a scenario in which microorganisms had dispersed from mānuka to non-mānuka phyllosphere microbiomes.
We conclude that host selection of phyllosphere communities is not and should not be presumed to be a universal trait across plant species. The specificity of the mānuka phyllosphere microbiome suggests the presence of functionally significant bacteria that are under direct, possibly chemically mediated, selection by the host. Furthermore, we propose that phyllosphere microbiomes under strong host selection, such as that of mānuka, may act as a source of microorganisms for the phyllosphere microbiomes of neighbouring plants. Video Abstract.
越来越多的证据表明，植物叶片表面（即叶际）与宿主相关的微生物群落能够影响宿主的功能性状。然而，宿主选择是否是叶际群落组装的普遍驱动因素仍不清楚。我们以新西兰本土灌木丛中一条1800米长的样带中的麦卢卡树（Leptospermum scoparium）和三种相邻的非麦卢卡植物物种为研究对象，对宿主物种身份和随机扩散对天然叶际细菌群落组成的相对影响进行了一项假设驱动的调查。
我们检测到宿主物种身份与麦卢卡树叶际群落之间存在显著相关性，这与宿主选择在麦卢卡树叶际微生物组组装中的主导作用一致。相比之下，相邻的、生态上相似的本土植物的叶际群落组成高度可变，这表明随机过程，如扩散，对那些非麦卢卡植物的叶际微生物组的影响比对麦卢卡树叶际微生物组的影响更强。此外，叶际分类群在植物物种之间的分布与微生物从麦卢卡树扩散到非麦卢卡树叶际微生物组的情况相符。
我们得出结论，叶际群落的宿主选择不是，也不应被假定为所有植物物种的普遍特征。麦卢卡树叶际微生物组的特异性表明存在功能上重要的细菌，这些细菌受到宿主的直接选择，可能是化学介导的选择。此外，我们提出，受到强烈宿主选择的叶际微生物组，如麦卢卡树的叶际微生物组，可能作为相邻植物叶际微生物组的微生物来源。视频摘要。
