Trunk injection of antibiotics has re-emerged as a strategy to mitigate citrus huanglongbing (HLB), a devastating disease associated with the bacterium Candidatus Liberibacter asiaticus (CLas). Despite commercial adoption in Florida, no studies have examined how oxytetracycline (OTC) injection may impact active plant-associated microbial communities. We investigated the impact of OTC trunk injection on tree physiological parameters, HLB control, and the prokaryotic and eukaryotic microbiome of the active inner bark and rhizosphere in a commercial citrus orchard under HLB-endemic conditions. OTC injection significantly increased juice quality and fruit weight. OTC was detected in leaves, bark, and roots but concentrations varied with time and across plant tissues. OTC injection reduced the abundance and diversity of the active prokaryotic microbiome in the bark and rhizosphere during the first three months post-injection. Specific prokaryotic taxa were responsive to OTC injection and their relative abundances related to increased plant performance. This study shows that OTC injection can promote the recovery of tree physiological functions impacted by HLB while also maximizing the benefits from certain prokaryotes of the bark and rhizosphere microbiomes.

树干注射抗生素已重新成为减轻柑橘黄龙病（HLB）的一种策略，柑橘黄龙病是一种与亚洲自由杆菌（CLas）细菌相关的毁灭性疾病。尽管在佛罗里达州进行了商业采用，但没有研究探讨土霉素（OTC）注射如何影响活跃的植物相关微生物群落。我们研究了 HLB 流行条件下商业柑橘园中 OTC 树干注射对树木生理参数、HLB 控制以及活性内树皮和根际的原核和真核微生物组的影响。 OTC注射液显着提高了果汁质量和果实重量。 OTC 在叶子、树皮和根中检测到，但浓度随时间和植物组织的变化而变化。在注射后的前三个月内，OTC 注射降低了树皮和根际活性原核微生物组的丰度和多样性。特定的原核类群对 OTC 注射有反应，其相对丰度与植物性能的提高相关。这项研究表明，OTC 注射可以促进受 HLB 影响的树木生理功能的恢复，同时还能最大限度地发挥树皮和根际微生物组某些原核生物的益处。