Maintenance of a beneficial microbial community, especially in the rhizosphere, is indispensable for plant growth and agricultural sustainability. In this sense, plant growth-promoting rhizobacteria (PGPR) have been extensively studied for their role in plant growth promotion and disease resistance. However, the impact of introducing PGPR strains into rhizosphere microbial communities is still underexplored. We previously found that the Proteus vulgaris JBLS202 strain (JBLS202) promoted growth of Kimchi cabbage and altered the relative abundance of total bacteria and Pseudomonas spp. in the treated rhizosphere. To extend these findings, we used pyrosequencing to analyze the changes in bacterial communities in the rhizosphere of Kimchi cabbage after introduction of JBLS202. The alterations were also evaluated by taxon-specific real-time PCR (qPCR). The pyrosequencing data revealed an increase in total bacteria abundance, including specific groups such as Proteobacteria, Acidobacteria, and Actinobacteria, in the treated rhizosphere. Time-course qPCR analysis confirmed the increase in the abundance of Acidobacteria, Actinobacteria, Alphaproteobacteria, and Betaproteobacteria. Furthermore, genes involved in nitrogen cycling were upregulated by JBLS202 treatment indicating changes in ecological function of the rhizosphere soil. Overall, these results indicate that introduction of JBLS202 alters both the composition and function of the rhizosphere bacterial community, which can have direct and indirect effects on plant growth. Therefore, we propose that long-term changes in bacterial composition and community-level function need to be considered for practical use of PGPRs.

中文翻译：

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寻常变形杆菌JBLS202对种子进行泡菜后，泡菜白菜根际细菌群落的分类和功能变化。

维持有益的微生物群落，尤其是在根际中，对于植物生长和农业可持续发展是必不可少的。从这个意义上说，已经广泛研究了促进植物生长的根际细菌（PGPR）在植物生长促进和抗病性中的作用。然而，将PGPR菌株引入根际微生物群落的影响仍未得到充分研究。我们以前发现，普通变形杆菌JBLS202株（JBLS202）促进泡菜白菜的生长，改变了细菌总数和相对丰富假单胞菌属。在经过处理的根际中。为了扩展这些发现，我们使用焦磷酸测序分析了引入JBLS202后泡菜白菜根际细菌群落的变化。还通过分类群特异性实时PCR（qPCR）评估了这些改变。焦磷酸测序数据显示，处理后的根际中细菌总数丰富，包括变形杆菌，酸性杆菌和放线菌等特定群体。时程qPCR分析证实了酸性细菌，放线菌，α变形杆菌和Beta变形杆菌的丰度增加。此外，JBLS202处理上调了参与氮循环的基因，表明根际土壤生态功能发生了变化。全面的，这些结果表明，引入JBLS202会改变根际细菌群落的组成和功能，从而对植物的生长产生直接和间接的影响。因此，我们建议在实际使用PGPR时需要考虑细菌组成和社区水平功能的长期变化。