Title |
Poly-γ-glutamic acid productivity of Bacillus subtilis BsE1 has positive function in motility and biocontrol against Fusarium graminearum |
Author |
Luyao Wang1, Ning Wang1, Dandan Mi1, Yuming Luo2*, and Jianhua Guo1* |
Address |
1Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University; Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection; Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; Nanjing 210095, P. R. China, 2Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, School of Life Science, Huaiyin Normal University, Huaian 223300, P. R. China |
Bibliography |
Journal of Microbiology, 55(7),554–560, 2017,
|
DOI |
10.1007/s12275-017-6589-y
|
Key Words |
biocontrol, poly-γ-glutamic acid, motility, root
colonization, Fusarium root rot |
Abstract |
In this study, we investigate the relationship between γ-PGA
productivity and biocontrol capacity of Bacillus subtilis BsE1;
one bacterial isolate displayed 62.14% biocontrol efficacy
against Fusarium root rot. The γ-PGA yield assay, motility
assay, wheat root colonization assay, and biological control
assay were analysed in different γ-PGA yield mutants of BsE1.
The pgsB (PGA-synthase-CapB gene) deleted mutant of BsE1
reduced γ-PGA yield and exhibited apparent decline of in
vitro motile ability. Deletion of pgsB impaired colonizing capacity
of BsE1 on wheat root in 30 days, also lowered biocontrol
efficacies from 62.08% (wild type BsE1) to 14.22% in
greenhouse experiment against Fusarium root rot. The knockout
of pgdS and ggt (genes relate to two γ-PGA degrading
enzymes) on BsE1, leads to a considerable improvement in
polymer yield and biocontrol efficacy, which attains higher
level compared with wild type BsE1. Compared with ΔpgsB
mutant, defense genes related to reactive oxygen species (ROS)
and phytoalexin expressed changes by notable levels on wheat
roots treated with BsE1, demonstrating the functional role
γ-PGA plays in biocontrol against Fusarium root rot. γ-PGA
is not only important to the motile and plant root colonization
ability of BsE1, but also essential to the biological control
performed by BsE1 against Fusarium root rot. Our goal
in this study is to reveals a new perspective of BCAs screening
on bacterial isolates, without good performance during
pre-assays of antagonism ability. |