title: GDSL LIPASE1 modulates plant immunity through feedback regulation of ethylene signaling.
abstract: Ethylene is a key signal in the regulation of plant defense responses. It is required for the expression and function of GDSL LIPASE1 (GLIP1) in Arabidopsis (Arabidopsis thaliana), which plays an important role in plant immunity. Here, we explore molecular mechanisms underlying the relationship between GLIP1 and ethylene signaling by an epistatic analysis of ethylene response mutants and GLIP1-overexpressing (35S:GLIP1) plants. We show that GLIP1 expression is regulated by ethylene signaling components and, further, that GLIP1 expression or application of petiole exudates from 35S:GLIP1 plants affects ethylene signaling both positively and negatively, leading to ETHYLENE RESPONSE FACTOR1 activation and ETHYLENE INSENSITIVE3 (EIN3) down-regulation, respectively. Additionally, 35S:GLIP1 plants or their exudates increase the expression of the salicylic acid biosynthesis gene SALICYLIC ACID INDUCTION-DEFICIENT2, known to be inhibited by EIN3 and EIN3-LIKE1. These results suggest that GLIP1 regulates plant immunity through positive and negative feedback regulation of ethylene signaling, and this is mediated by its activity to accumulate a systemic signal(s) in the phloem. We propose a model explaining how GLIP1 regulates the fine-tuning of ethylene signaling and ethylene-salicylic acid cross talk.
authors.affiliation: Division of Life Sciences, Korea University, Seoul 136-701, Korea.
authors.forename: Hye Gi
authors.initials: HG
authors.lastname: Kim
authors.forename: Sun Jae
authors.initials: SJ
authors.lastname: Kwon
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Jang
authors.forename: Myung Hee
authors.initials: MH
authors.lastname: Nam
authors.forename: Joo Hee
authors.initials: JH
authors.lastname: Chung
authors.forename: Yun-Cheol
authors.initials: YC
authors.lastname: Na
authors.forename: Hongwei
authors.initials: H
authors.lastname: Guo
authors.forename: Ohkmae K
authors.initials: OK
authors.lastname: Park
mesh_terms: D000528:Alternaria / Q000502:physiology; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D060467:Disease Resistance / Q000235:genetics / Q000276:immunology; D015536:Down-Regulation / Q000235:genetics; D004843:Epistasis, Genetic; D005030:Ethylenes / Q000378:metabolism*; D025461:Feedback, Physiological; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D053147:Plant Exudates / Q000378:metabolism; D057865:Plant Immunity / Q000235:genetics; D011485:Protein Binding; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D005030:Ethylenes; D053147:Plant Exudates; C036216:ethylene; D002265:Carboxylic Ester Hydrolases; C508002:Glip1 protein, Arabidopsis; D020156:Salicylic Acid