Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing, China.
Appl Microbiol Biotechnol. 2017 Jun;101(12):5199-5212. doi: 10.1007/s00253-017-8247-z. Epub 2017 Mar 28.
Colonization by polycyclic aromatic hydrocarbon (PAH)-degrading endophytic bacteria (PAHDEB) can reduce the PAH contamination risk in plant. However, little information is available on the impact of PAHDEB colonization on the endophytic bacterial community of inner plant tissues. A phenanthrene-degrading endophytic bacterium (PDEB), Massilia sp. Pn2, was inoculated onto the roots of wheat and subjected to greenhouse container experiments. The endophytic bacterial community structure in wheat was investigated using high-throughput sequencing technology. The majority of endophytic bacteria in wheat were Proteobacteria, and the dominant genus was Pseudomonas. Phenanthrene contamination clearly increased the diversity of endophytic bacteria in wheat. The cultivable endophytic bacteria counts in wheat decreased with increasing the level of phenanthrene contamination; the endophytic bacterial community structure changed correspondingly, and the bacterial richness first increased and then decreased. Inoculation of strain Pn2 reduced the phenanthrene contamination in wheat, enlarged the biomass of wheat roots, changed the bacterial community structure and enhanced the cell counts, diversity and richness of endophytic bacteria in phenanthrene-contaminated wheat in a contamination level-dependent manner. The findings of this investigation provide insight into the responses of endophytic bacterial community in plant to external PAH contamination and PAHDEB colonization.
多环芳烃（PAH）降解内生细菌（PAHDEB）的定殖可以降低植物中 PAH 的污染风险。然而，关于 PAHDEB 定殖对植物内部组织内生细菌群落的影响的信息很少。一株菲降解内生细菌（PDEB），即粪产碱菌（Massilia sp.）Pn2，被接种到小麦的根部，并进行温室容器实验。使用高通量测序技术研究了小麦内生细菌群落的结构。小麦中的大多数内生细菌为变形菌门，优势属为假单胞菌属。菲污染明显增加了小麦内生细菌的多样性。随着菲污染水平的增加，小麦内生细菌的可培养数量减少；内生细菌群落结构相应发生变化，细菌丰富度先增加后减少。接种 Pn2 菌株降低了小麦中的菲污染，扩大了小麦根的生物量，改变了细菌群落结构，并以污染水平依赖的方式增强了受菲污染小麦中内生细菌的细胞计数、多样性和丰富度。本研究的结果深入了解了植物内生细菌群落对外部 PAH 污染和 PAHDEB 定殖的响应。
