Burkholderia species have different lifestyles establishing mutualist or pathogenic associations with plants and animals. Changes in the ecological behavior of these bacteria may depend on genetic variations in response to niche adaptation. Here, we studied 15 Burkholderia strains isolated from different environments with respect to genetic and phenotypic traits. By Multilocus Sequence Analysis (MLSA) these isolates fell into 6 distinct groups. MLSA clusters did not correlate with strain antibiotic sensitivity, but with the bacterial ability to produce antimicrobial compounds and control orchid necrosis. Further, the B. seminalis strain TC3.4.2R3, a mutualistic bacterium, was inoculated into orchid plants and the interaction with the host was evaluated by analyzing the plant response and the bacterial oxidative stress response in planta. TC3.4.2R3 responded to plant colonization by increasing its own growth rate and by differential gene regulation upon oxidative stress caused by the plant, while reducing the plant's membrane lipid peroxidation. The bacterial responses to oxidative stress were recapitulated by bacterial exposure to the herbicide paraquat. We suggest that the ability of Burkholderia species to successfully establish in the rhizosphere correlates with genetic variation, whereas traits associated with antibiotic resistance are more likely to be categorized as strain specific.

伯克霍尔德氏菌物种有不同的生活方式，可与植物和动物建立互惠或致病的联系。这些细菌生态行为的变化可能取决于对生态位适应的遗传变异。在这里，我们研究了从不同环境中分离的15个伯克霍尔德菌菌株的遗传和表型特征。通过多基因座序列分析（MLSA），这些分离物分为6个不同的组。MLSA簇与菌株对抗生素的敏感性无关，但与细菌产生抗菌化合物和控制兰花坏死的能力无关。此外，半裸芽孢杆菌将一种共生细菌TC3.4.2R3株接种到兰花植物中，并通过分析植物中的植物响应和细菌氧化应激响应来评估与宿主的相互作用。TC3.4.2R3通过增加自身的生长速率和通过对植物引起的氧化胁迫的差异基因调控来响应植物定植，同时减少植物的膜脂过氧化。细菌暴露于除草剂百草枯可概括细菌对氧化应激的反应。我们建议伯克霍尔德菌种在根际中成功建立的能力与遗传变异相关，而与抗生素抗性相关的性状更可能归为菌株特异性。