Russ Dor, Fitzpatrick Connor R, Saha Chinmay, Law Theresa F, Jones Corbin D, Kliebenstein Daniel J, Dangl Jeffery L
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Nat Commun. 2025 Jul 1;16(1):5699. doi: 10.1038/s41467-025-61266-3.
In nature, plants recruit a diverse microbial community, the plant microbiome, that is distinct from the surrounding soil community. To understand the forces that shape the plant microbiome we need to characterize the microbial traits that contribute to plant colonization. We used barcoded mutant libraries to identify bacterial genes that contribute to the colonization of a monocot and a eudicot host. We show that plant colonization is influenced by dozens of genes. While some of these colonization genes were shared between the two host plant species, most were highly specific, benefiting the colonization of a single host and organ. We characterized an efflux pump that specifically contributes to Arabidopsis shoot colonization. This efflux pump is prevalent across Pseudomonadota genomes yet benefits the bacterial association with only a small subset of Arabidopsis thaliana accessions. Leveraging genomic diversity within Arabidopsis thaliana, we confirmed that specific glucosinolate breakdown products are detoxified by this family of efflux pumps. The broad prevalence of this efflux pump family suggests that its members contribute to protection of commensal bacteria from collateral damage of plant glucosinolate-based defense responses to herbivores and necrotrophic pathogens.
在自然界中，植物会招募一个多样的微生物群落，即植物微生物组，它与周围的土壤群落不同。为了了解塑造植物微生物组的力量，我们需要表征有助于植物定殖的微生物特征。我们使用条形码突变体文库来鉴定有助于单子叶植物和双子叶植物宿主定殖的细菌基因。我们发现植物定殖受到数十个基因的影响。虽然其中一些定殖基因在两种宿主植物物种之间是共享的，但大多数基因具有高度特异性，有利于单个宿主和器官的定殖。我们鉴定了一种外排泵，它对拟南芥地上部分的定殖有特异性贡献。这种外排泵在假单胞菌门基因组中普遍存在，但仅有利于与一小部分拟南芥种质的细菌关联。利用拟南芥中的基因组多样性，我们证实了特定的芥子油苷分解产物被这个外排泵家族解毒。这个外排泵家族的广泛存在表明，其成员有助于保护共生细菌免受植物基于芥子油苷的防御反应对食草动物和坏死营养型病原体的附带损害。
