title: Modulation of Quorum Sensing in Acylhomoserine Lactone-Producing or -Degrading Tobacco Plants Leads to Alteration of Induced Systemic Resistance Elicited by the Rhizobacterium Serratia marcescens 90-166.
abstract: Numerous root-associated bacteria (rhizobacteria) are known to elicit induced systemic resistance (ISR) in plants. Bacterial cell-density-dependent quorum sensing (QS) is thought to be important for ISR. Here, we investigated the role of QS in the ISR elicited by the rhizobacterium, Serratia marcescens strain 90-166, in tobacco. Since S. marcescens 90-166 produces at least three QS signals, QS-mediated ISR in strain 90-166 has been difficult to understand. Therefore, we investigated the ISR capacity of two transgenic tobacco (Nicotiana tabacum) plants that contained either bacterial acylhomoserine lactone-producing (AHL) or -degrading (AiiA) genes in conjunction with S. marcescens 90-166 to induce resistance against bacterial and viral pathogens. Root application of S. marcescens 90-166 increased ISR to the bacterial pathogens, Pectobacterium carotovorum subsp. carotovorum and Pseudomonas syringae pv. tabaci, in AHL plants and decreased ISR in AiiA plants. In contrast, ISR to Cucumber mosaic virus was reduced in AHL plants treated with S. marcescens 90-166 but enhanced in AiiA plants. Taken together, these data indicate that QS-dependent ISR is elicited by S. marcescens 90-166 in a pathogen-dependent manner. This study provides insight into QS-dependent ISR in tobacco elicited by S. marcescens 90-166.
authors.affiliation: Molecular Phytobacteriology Laboratory, Systems and Synthetic Biology Research Center, KRIBB, Daejeon 305-806, Korea ; Biosystems and Bioengineering Program, University of Science and Technology (UST), Daejeon 305-350, Korea.
authors.forename: Choong-Min
authors.initials: CM
authors.lastname: Ryu
authors.affiliation: Molecular Phytobacteriology Laboratory, Systems and Synthetic Biology Research Center, KRIBB, Daejeon 305-806, Korea.
authors.forename: Hye Kyung
authors.initials: HK
authors.lastname: Choi
authors.affiliation: Department of Biomedicinal Science & Biotechnology, Paichai University, Seo-Gu, Daejeon 302-735, Korea.
authors.forename: Chi-Ho
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Entomology and Plant Pathology, Auburn University, AL 36849-5409, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: Murphy
authors.affiliation: Department of Biomedicinal Science & Biotechnology, Paichai University, Seo-Gu, Daejeon 302-735, Korea.
authors.forename: Jung-Kee
authors.initials: JK
authors.lastname: Lee
authors.affiliation: Department of Entomology and Plant Pathology, Auburn University, AL 36849-5409, USA.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Kloepper
keywords: AiiA; N-Acyl homoserine lactone; plant-growth promoting rhizobacteria; quorum sensing