Vicario Julio C, Dardanelli Marta S, Giordano Walter
Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, 5800 Río Cuarto, Córdoba, Argentina.
Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, 5800 Río Cuarto, Córdoba, Argentina
FEMS Microbiol Lett. 2015 Jan;362(2):1-6. doi: 10.1093/femsle/fnu038. Epub 2014 Dec 4.
Motility allows populations of bacteria to rapidly reach and colonize new microniches or microhabitats. The motility of rhizobia (symbiotic nitrogen-fixing bacteria that nodulate legume roots) is an important factor determining their competitive success. We evaluated the effects of temperature, incubation time, and seed exudates on swimming and swarming motility of five strains of Bradyrhizobium sp. (peanut-nodulating rhizobia). Swimming motility was increased by exudate exposure for all strains except native Pc34. In contrast, swarming motility was increased by exudate exposure for native 15A but unchanged for the other four strains. All five strains displayed the ability to differentiate into swarm cells. Morphological examination by scanning electron microscopy showed that the length of the swarm cells was variable, but generally greater than that of vegetative cells. Our findings suggest the importance of differential motility properties of peanut-nodulating rhizobial strains during agricultural inoculation and early steps of symbiotic interaction with the host.
运动性使细菌群体能够迅速到达并定殖于新的微生态位或微生境。根瘤菌（与豆科植物根形成根瘤的共生固氮细菌）的运动性是决定其竞争成功的重要因素。我们评估了温度、孵育时间和种子渗出物对五株慢生根瘤菌（花生根瘤菌）游泳和群体运动性的影响。除本地菌株Pc34外，所有菌株的游泳运动性在接触渗出物后均增强。相比之下，本地菌株15A的群体运动性在接触渗出物后增强，而其他四株菌株则无变化。所有五株菌株均表现出分化为群体细胞的能力。通过扫描电子显微镜进行的形态学检查表明，群体细胞的长度各不相同，但通常大于营养细胞。我们的研究结果表明，花生根瘤菌菌株的不同运动特性在农业接种以及与宿主共生相互作用的早期阶段具有重要意义。
