title: Inoculation of a phenanthrene-degrading endophytic bacterium reduces the phenanthrene level and alters the bacterial community structure in wheat.
abstract: 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.
authors.affiliation: Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing, China.
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Xiang
authors.affiliation: Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing, China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing, China.
authors.forename: Wanting
authors.initials: W
authors.lastname: Ling
authors.affiliation: Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing, China. gaoyanzheng@njau.edu.cn.
authors.forename: Yanzheng
authors.initials: Y
authors.lastname: Gao
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D044822:Biodiversity; D060026:Endophytes / Q000502:physiology*; D059014:High-Throughput Nucleotide Sequencing; D059013:Microbial Consortia / Q000235:genetics / Q000502:physiology*; D010616:Phenanthrenes / Q000032:analysis / Q000378:metabolism*; D018517:Plant Roots / Q000382:microbiology; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism; D020560:Proteobacteria / Q000235:genetics / Q000302:isolation & purification; D011549:Pseudomonas / Q000235:genetics / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S; D014908:Triticum / Q000382:microbiology*
chemical_list: D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D012336:RNA, Ribosomal, 16S; C031181:phenanthrene
keywords: Bacterial community; Colonization; Endophytic bacteria; Phenanthrene degradation; Polycyclic aromatic hydrocarbons