title: Linoleic acid-induced expression of defense genes and enzymes in tobacco.
abstract: Linoleic acid (LA) is a naturally occurring fatty acid (FA) found to elicit induced systemic resistance (ISR) of tobacco against the bacterial soft rot pathogen, Pectobacterium carotovorum subsp. carotovorum (PCC). In this study, we examined effects of six doses of exogenous LA on the induction of defense genes and enzymes. The optimum ISR activity was observed in plants treated with 0.1mM LA where the effect of LA on membrane permeability was minimal. The application of LA as a root drench enhanced the activity of defense enzymes such as phenylalanine ammonia-lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO) and induced the expression of β-glucuronidase (GUS). PAL and POD activities were increased in a concentration dependent manner while the maximum PPO activity was observed after treatment with 0.01mM LA. An RT-PCR analysis of the defense-related genes, Coi1, NPR1, PR-1a and PR-1b, of tobacco plants treated with 0.1mM LA revealed an association of LA with elicitation of ISR in tobacco.
authors.affiliation: School of Life Sciences, KNU Creative Bioresearch Group (BK21 Plus Project) and Institute for Microorganisms, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Marilyn S
authors.initials: MS
authors.lastname: Sumayo
authors.affiliation: Department of Biology Education, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Duck-Kee
authors.initials: DK
authors.lastname: Kwon
authors.affiliation: School of Life Sciences, KNU Creative Bioresearch Group (BK21 Plus Project) and Institute for Microorganisms, Kyungpook National University, Daegu 702-701, Republic of Korea. Electronic address: ghimsa@knu.ac.kr.
authors.forename: Sa-Youl
authors.initials: SY
authors.lastname: Ghim
mesh_terms: D001483:Base Sequence; D004156:Catechol Oxidase / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D017931:DNA Primers; D019787:Linoleic Acid / Q000494:pharmacology*; D010544:Peroxidases / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics*
chemical_list: D017931:DNA Primers; D019787:Linoleic Acid; D004156:Catechol Oxidase; D010544:Peroxidases; D010650:Phenylalanine Ammonia-Lyase
keywords: Defense enzymes; Defense genes; Induced systemic resistance (ISR); Linoleic acid (LA); Pectobacterium carotovorum subsp. carotovorum (PCC)