Banana (Musa acuminata) growth for commercial purposes requires high amounts of chemical fertilizers, generating high costs and deleterious effects on the environment. In a previous study, we demonstrated that two plant growth-promoting rhizobacteria (PGPR), Bacillus amyloliquefaciens Bs006 and Pseudomonas palleroniana Ps006, isolated in Colombia, could partially replace chemical fertilizers for banana seedling growth. In a second work, the effects of the two inoculants on banana transcripts were found to occur at different times, earlier for Bs006 and later for Ps006. This leads to the hypothesis that the two rhizobacteria have different colonization dynamics. Accordingly, the aim of this work was to analyze the dynamics of root colonization of the two PGPR, Bs006 and Ps006, on banana growth over a time frame of 30 days. We used fluorescence in situ hybridization (FISH) and confocal laser scanning microscopy (CLSM), followed by three-dimensional reconstruction and quantitative image analysis. Bacillus amyloliquefaciens Bs006 abundantly colonized banana roots earlier (from 1 to 48 h), ectophytically on the rhizoplane, and then decreased. Pseudomonas palleroniana Ps006 was initially scarce, but after 96 h it increased dramatically and became clearly endophytic. Here we identify and discuss the potential genetic factors responsible for this complementary behavior. This information is crucial for optimizing the formulation of an effective biofertilizer for banana and its inoculation strategy.

用于商业目的的香蕉（Mus acuminata）生长需要大量的化学肥料，从而产生高成本和对环境的有害影响。在先前的研究中，我们证明了两种促进植物生长的根际细菌（PGPR），即解淀粉芽孢杆菌Bs006和假单胞菌在哥伦比亚隔离的Ps006，可以部分替代化肥，用于香蕉苗的生长。在第二项工作中，发现两种接种物对香蕉转录本的影响发生在不同的时间，Bs006较早，Ps006较晚。这导致了两个细菌的定殖动力学不同的假设。因此，这项工作的目的是分析两种PGPR（Bs006和Ps006）在30天时间内香蕉根生长的动态。我们使用荧光原位杂交（FISH）和共聚焦激光扫描显微镜（CLSM），然后进行三维重建和定量图像分析。淀粉芽孢杆菌Bs006较早（从1到48 h）在根际平面上富集了香蕉根，然后减少了。最初，Pseudomonas palleroniana Ps006稀缺，但在96小时后，其急剧增加并明显变得内生。在这里，我们确定并讨论了造成这种互补行为的潜在遗传因素。这些信息对于优化香蕉有效生物肥料的配方及其接种策略至关重要。