Interference of quorum sensing and virulence of the rice pathogen Burkholderia glumae by an engineered endophytic bacterium.
Many bacterial species are known to thrive within plants. Among these bacteria, a group referred to as endophytes provide beneficial effects to the host plants by the promotion of plant growth and the suppression of plant pathogens. Among 44 putative endophytic isolates isolated from surface-sterilized rice roots, Burkholderia sp. KJ006 was selected for further study because of a lack of pathogenicity to rice, a broad spectrum of antifungal properties, and the presence of the nifH gene, which is an indicator for nitrogen fixation. In an attempt to control Burkholderia glumae, a casual pathogen of seedling rot and grain rot of rice, an N-acyl-homoserine lactonase (aiiA) gene from Bacillus thuringiensis was introduced into Burkholderia sp. KJ006 given that the major virulence factor of Burkholderia glumae is controlled in a population-dependent manner (quorum sensing). The engineered strain KJ006 (pKPE-aiiA) inhibited production of quorum-sensing signals by Burkholderia glumae in vitro and reduced the disease incidence of rice seedling rot caused by Burkholderia glumae in situ. Our results indicate the possibility that a bacterial endophyte transformed with the aiiA gene can be used as a novel biological control agent against pathogenic Burkholderia glumae that are known to occupy the same ecological niche.
Cho
Hyun-Soo
HS
Laboratory of Microbial Genomics, Systems Microbiology Research Center, KRIBB, Daejeon 305-806, Korea.
Park
Soo-Young
SY
Ryu
Choong-Min
CM
Kim
Jihyun F
JF
Kim
Jong-Guk
JG
Park
Seung-Hwan
SH
D000898:Antibiosis; D001413:Bacillus thuringiensis / Q000201:enzymology / Q000235:genetics; D019117:Burkholderia / Q000145:classification / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism; D005818:Genetic Engineering / Q000379:methods*; D012275:Oryza / Q000382:microbiology*; D010572:Pest Control, Biological; D010935:Plant Diseases / Q000382:microbiology; D053038:Quorum Sensing; D014774:Virulence
D002265:Carboxylic Ester Hydrolases; C432003:N-acyl homoserine lactonase