Soto María José, Pérez Juana, Muñoz-Dorado José, Contreras-Moreno Francisco Javier, Moraleda-Muñoz Aurelio
Departamento de Biotecnología y Protección Ambiental, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain.
Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
Front Microbiol. 2023 Jun 19;14:1213659. doi: 10.3389/fmicb.2023.1213659. eCollection 2023.
Bacterial predation impacts microbial community structures, which can have both positive and negative effects on plant and animal health and on environmental sustainability. is an epibiotic soil predator with a broad range of prey, including , which establishes nitrogen-fixing symbiosis with legumes. During the - interaction, the predator must adapt its transcriptome to kill and lyse the target (predatosome), and the prey must orchestrate a transcriptional response (defensome) to protect itself against the biotic stress caused by the predatory attack. Here, we describe the transcriptional changes taking place in in response to myxobacterial predation. The results indicate that the predator induces massive changes in the prey transcriptome with up-regulation of protein synthesis and secretion, energy generation, and fatty acid (FA) synthesis, while down-regulating genes required for FA degradation and carbohydrate transport and metabolism. The reconstruction of up-regulated pathways suggests that modifies the cell envelop by increasing the production of different surface polysaccharides (SPSs) and membrane lipids. Besides the barrier role of SPSs, additional mechanisms involving the activity of efflux pumps and the peptide uptake transporter BacA, together with the production of HO and formaldehyde have been unveiled. Also, the induction of the iron-uptake machinery in both predator and prey reflects a strong competition for this metal. With this research we complete the characterization of the complex transcriptional changes that occur during the - interaction, which can impact the establishment of beneficial symbiosis with legumes.
细菌捕食会影响微生物群落结构，这对动植物健康以及环境可持续性可能产生积极和消极影响。粘细菌是一种体表土壤捕食者，其猎物范围广泛，包括与豆科植物建立固氮共生关系的根瘤菌。在粘细菌与根瘤菌的相互作用过程中，捕食者必须调整其转录组以杀死并裂解目标（捕食体），而猎物则必须精心策划一种转录反应（防御体）来保护自身免受捕食攻击所导致的生物胁迫。在此，我们描述了根瘤菌对粘细菌捕食所产生的转录变化。结果表明，捕食者会诱导猎物转录组发生大量变化，蛋白质合成与分泌、能量生成以及脂肪酸（FA）合成上调，而脂肪酸降解以及碳水化合物运输与代谢所需的基因则下调。上调途径的重建表明，根瘤菌通过增加不同表面多糖（SPS）和膜脂的产生来修饰细胞包膜。除了表面多糖的屏障作用外，还揭示了涉及外排泵和肽摄取转运体BacA活性以及过氧化氢和甲醛产生的其他机制。此外，捕食者和猎物中铁摄取机制的诱导反映了对这种金属的激烈竞争。通过这项研究，我们完成了对粘细菌与根瘤菌相互作用过程中发生的复杂转录变化的表征，这些变化可能会影响与豆科植物有益共生关系的建立。
