title: Galactinol is a signaling component of the induced systemic resistance caused by Pseudomonas chlororaphis O6 root colonization.
abstract: Root colonization by Pseudomonas chlororaphis O6 in cucumber elicited an induced systemic resistance (ISR) against Corynespora cassiicola. In order to gain insight into O6-mediated ISR, a suppressive subtractive hybridization technique was applied and resulted in the isolation of a cucumber galactinol synthase (CsGolS1) gene. The transcriptional level of CsGolS1 and the resultant galactinol content showed an increase several hours earlier under O6 treatment than in the water control plants following C. cassiicola challenge, whereas no difference was detected in the plants without a pathogen challenge. The CsGolS1-overexpressing transgenic tobacco plants demonstrated constitutive resistance against the pathogens Botrytis cinerea and Erwinia carotovora, and they also showed an increased accumulation in galactinol content. Pharmaceutical application of galactinol enhanced the resistance against pathogen infection and stimulated the accumulation of defense-related gene transcripts such as PR1a, PR1b, and NtACS1 in wild-type tobacco plants. Both the CsGolS1-overexpressing transgenic plants and the galactinol-treated wild-type tobacco plants also demonstrated an increased tolerance to drought and high salinity stresses.
authors.affiliation: Agricultural Plant Stress Research Center, Biotechnology Research Institute, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Mi Seong
authors.initials: MS
authors.lastname: Kim
authors.forename: Song Mi
authors.initials: SM
authors.lastname: Cho
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Kang
authors.forename: Yang Ju
authors.initials: YJ
authors.lastname: Im
authors.forename: Hoon
authors.initials: H
authors.lastname: Hwangbo
authors.forename: Young Cheol
authors.initials: YC
authors.lastname: Kim
authors.forename: Choong-Min
authors.initials: CM
authors.lastname: Ryu
authors.forename: Kwang Yeol
authors.initials: KY
authors.lastname: Yang
authors.forename: Gap Chae
authors.initials: GC
authors.lastname: Chung
authors.forename: Baik Ho
authors.initials: BH
authors.lastname: Cho
mesh_terms: D001203:Ascomycota / Q000472:pathogenicity; D020171:Botrytis / Q000472:pathogenicity; D018553:Cucumis sativus / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000382:microbiology; D004187:Disaccharides / Q000494:pharmacology*; D005700:Galactosyltransferases / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate; D016973:Pectobacterium carotovorum / Q000472:pathogenicity; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000382:microbiology; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D011549:Pseudomonas / Q000254:growth & development*; D018749:RNA, Plant / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013312:Stress, Physiological; D013559:Symbiosis; D014026:Nicotiana / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D014170:Transformation, Genetic
chemical_list: D004187:Disaccharides; D010940:Plant Proteins; D018749:RNA, Plant; C013536:6 beta-galactinol; D005700:Galactosyltransferases; C096645:inositol 1-alpha-galactosyltransferase