Galactinol is a signaling component of the induced systemic resistance caused by Pseudomonas chlororaphis O6 root colonization.
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.
Kim
Mi Seong
MS
Agricultural Plant Stress Research Center, Biotechnology Research Institute, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea.
Cho
Song Mi
SM
Kang
Eun Young
EY
Im
Yang Ju
YJ
Hwangbo
Hoon
H
Kim
Young Cheol
YC
Ryu
Choong-Min
CM
Yang
Kwang Yeol
KY
Chung
Gap Chae
GC
Cho
Baik Ho
BH
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
D004187:Disaccharides; D010940:Plant Proteins; D018749:RNA, Plant; C013536:6 beta-galactinol; D005700:Galactosyltransferases; C096645:inositol 1-alpha-galactosyltransferase