Department of Biological Sciences, University of South Carolina, Columbia, SC, United State of America.
PLoS One. 2021 Apr 1;16(4):e0249227. doi: 10.1371/journal.pone.0249227. eCollection 2021.
Bacteria play an integral role in shaping plant growth and development. However, the genetic factors that facilitate plant-bacteria interactions remain largely unknown. Here, we demonstrated the importance of two bacterial genetic factors that facilitate the interactions between plant-growth-promoting (PGP) bacteria in the genus Caulobacter and the host plant Arabidopsis. Using homologous recombination, we disrupted the cytochrome ubiquinol oxidase (cyo) operon in both C. vibrioides CB13 and C. segnis TK0059 by knocking out the expression of cyoB (critical subunit of the cyo operon) and showed that the mutant strains were unable to enhance the growth of Arabidopsis. In addition, disruption of the cyo operon, metabolomic reconstructions, and pH measurements suggested that both elevated cyoB expression and acid production by strain CB13 contribute to the previously observed inhibition of Arabidopsis seed germination. We also showed that the crescent shape of the PGP bacterial strain C. crescentus CB15 contributes to its ability to enhance plant growth. Thus, we have identified specific genetic factors that explain how select Caulobacter strains interact with Arabidopsis plants.
细菌在塑造植物生长和发育方面发挥着不可或缺的作用。然而，促进植物-细菌相互作用的遗传因素在很大程度上仍是未知的。在这里，我们证明了两个细菌遗传因素的重要性，这两个因素促进了植物促生（PGP）细菌属中的节杆菌和宿主植物拟南芥之间的相互作用。我们使用同源重组敲除了 C. vibrioides CB13 和 C. segnis TK0059 中的细胞色素 ubiquinol 氧化酶（cyo）操纵子，敲除了 cyoB（cyo 操纵子的关键亚基）的表达，并表明突变株无法增强拟南芥的生长。此外，cyo 操纵子的破坏、代谢组重建和 pH 测量表明，菌株 CB13 中 cyoB 表达的升高和酸的产生都有助于先前观察到的拟南芥种子萌发抑制。我们还表明，PGP 细菌菌株 C. crescentus CB15 的新月形有助于其增强植物生长的能力。因此，我们已经确定了特定的遗传因素，这些因素解释了特定的节杆菌菌株如何与拟南芥植物相互作用。
