Plant microbiomes are pivotal for healthy plant physiological development. Microbes live in complex co-association with plant hosts, and interactions within these microbial communities vary with plant genotype, plant compartment, phenological stage, and soil properties, among others. Plant microbiomes also harbor a substantial and diverse pool of mobile genes encoded on plasmids. Several plasmid functions attributed to plant-associated bacteria are relatively poorly understood. Additionally, the role of plasmids in disseminating genetic traits within plant compartments is not well known. Here, we present the current knowledge on the occurrence, diversity, function, and transfer of plasmids in plant microbiomes, emphasizing the factors that could modulate gene transfer in-planta. We also describe the role of the plant microbiome as a plasmid reservoir and the dissemination of its genetic material. We include a brief discussion on the current methodological limitations in studying plasmid transfer within plant microbiomes. This information could be useful to elucidate the dynamics of the bacterial gene pools, the adaptations different organisms have made, and variations in bacterial populations that might have never been described before, particularly in complex microbial communities associated with plants in natural and anthropogenic impacted environments.

植物微生物组对于健康的植物生理发育至关重要。微生物与植物宿主存在着复杂的共生关系，这些微生物群落内的相互作用随着植物基因型、植物区室、物候阶段和土壤性质等的不同而变化。植物微生物组还拥有大量由质粒编码的可移动基因库。对植物相关细菌的几种质粒功能了解相对较少。此外，质粒在植物区室内传播遗传性状的作用尚不清楚。在这里，我们介绍了植物微生物组中质粒的发生、多样性、功能和转移的最新知识，强调了可以调节植物内基因转移的因素。我们还描述了植物微生物组作为质粒库的作用及其遗传物质的传播。我们简要讨论了当前研究植物微生物组内质粒转移的方法学局限性。这些信息可能有助于阐明细菌基因库的动态、不同生物体所做的适应以及以前可能从未描述过的细菌种群的变化，特别是在自然和人为影响环境中与植物相关的复杂微生物群落中。