title: The ecological roles of Bacillus thuringiensis within phyllosphere environments.
abstract: Bacillus thuringiensis (Bt) is one of the most used bio-control agents to control plant insects, but little is known about its effect on the microbial population and communities on plant leaves. With the culture dependent method, it has been observed that the dynamics of Bt within the phyllosphere varied dependent on both the doses of Bt sprayed on the leaves and the plant species, however, Bt's population size kept stable at about 1000 cfu g(-1) after 15 d since inoculation. By comparing the bacterial abundances and community structures within the phyllosphere of three plant species, we confirmed that Bt at the doses of 1.5×10(7) and 1.5×10(9) cfu mL(-1) respectively did not significantly influence the natural bacterial population size on the leaf surfaces based on culture dependent assay. However, based on culture independent denaturing gradient gel electrophoresis (DGGE), Shannon-Wiener index (H') and Unweighted Pair Group Method with Arithmetic Mean (UPGMA) analysis, Bt has a significant influence on the bacterial communities within the phyllosphere of amaranth and cotton, but not rice. These results indicate that Bt exhibits different behaviors and ecological roles on the microbial diversity within the phyllosphere, and its environmental safety has to be concerned and evaluated in the future.
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Hankou Road 22, Nanjing 210093, PR China.
authors.forename: Xiaoxian
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Hankou Road 22, Nanjing 210093, PR China. Electronic address: xueyr@nju.edu.cn.
authors.forename: Yarong
authors.initials: Y
authors.lastname: Xue
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Hankou Road 22, Nanjing 210093, PR China.
authors.forename: Meizhe
authors.initials: M
authors.lastname: Han
authors.affiliation: Nanjing Institute of Environmental Sciences, MEP, Jiang Wang Miao Street 8, Nanjing 210042, PR China.
authors.forename: Yuanqing
authors.initials: Y
authors.lastname: Bu
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Hankou Road 22, Nanjing 210093, PR China. Electronic address: chliu@nju.edu.cn.
authors.forename: Changhong
authors.initials: C
authors.lastname: Liu
mesh_terms: D027721:Amaranthus / Q000378:metabolism / Q000382:microbiology; D000898:Antibiosis; D001413:Bacillus thuringiensis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D044822:Biodiversity; D055669:Ecological and Environmental Phenomena; D016521:Electrophoresis, Gel, Pulsed-Field; D003368:Gossypium / Q000378:metabolism / Q000382:microbiology; D012275:Oryza / Q000378:metabolism / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: Bacillus thuringiensis; Community structure; Microbial population; Phyllosphere