title: Absence of endo-1,4-β-glucanase KOR1 alters the jasmonate-dependent defence response to Pseudomonas syringae in Arabidopsis.
abstract: During plant-pathogen interactions, the plant cell wall forms part of active defence against invaders. In recent years, cell wall-editing enzymes, associated with growth and development, have been related to plant susceptibility or resistance. Our previous work identified a role for several tomato and Arabidopsis endo-1,4-β-glucanases (EGs) in plant-pathogen interactions. Here we studied the response of the Arabidopsis thaliana T-DNA insertion mutant lacking EG Korrigan1 (KOR1) infected with Pseudomonas syringae. KOR1 is predicted to be an EG which is thought to participate in cellulose biosynthesis. We found that kor1-1 plants were more susceptible to P. syringae, and displayed severe disease symptoms and enhanced bacterial growth if compared to Wassilewskija (Ws) wild-type plants. Hormonal and gene expression analyses revealed that the jasmonic acid (JA) pathway was activated more in kor1-1 plants with an increase in the JA-biosynthesis gene LOX3 and a greater accumulation of JA. Upon infection the accumulation of JA and JA-isoleucine (JA-Ile) was higher than in wild-type plants and increased the induction of LOX3 and the JA-responsive PDF1.2 gene. In addition, the increase of salicylic acid (SA) in healthy and infected kor1-1 may reflect the complex interaction between JA and SA, which results in the more susceptible phenotype displayed by the infected mutant plants. Callose deposition was enhanced in infected kor1-1 and an increase in pathogen-induced hydrogen peroxide took place. The susceptible phenotype displayed by KOR1-deficient plants was coronatine-independent. No significant changes were detected in the hormonal profile of the kor1-1 plants infected by coronatine-deficient P. syringae cmaA, which supports that absence of EG KOR1 alters per se the plant response to infection. We previously reported increased resistance of kor1-1 to B. cinerea, hence, the lack of this EG alters cell wall properties and plant responses in such a way that benefits P. syringae colonisation but restricts B. cinerea invasion.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universidad de Valencia, IATA (CSIC), Avda Agustín Escardino 7, 46980 Paterna, Valencia, Spain. Electronic address: Jaime.lopez-cruz@uv.es.
authors.forename: Jaime
authors.initials: J
authors.lastname: López-Cruz
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universidad de Valencia, IATA (CSIC), Avda Agustín Escardino 7, 46980 Paterna, Valencia, Spain. Electronic address: ivan.finiti@uv.es.
authors.forename: Ivan
authors.initials: I
authors.lastname: Finiti
authors.affiliation: Laboratorio de Bioquímica y Biotecnología, Área de Fisiología Vegetal, Departamento de Ciencias Agrarias y del Medio Natural, ESTCE, Universitat Jaume I, 12071 Castellón, Spain. Electronic address: ecrespo@guest.uji.es.
authors.forename: Emma
authors.initials: E
authors.lastname: Fernández-Crespo
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universidad de Valencia, IATA (CSIC), Avda Agustín Escardino 7, 46980 Paterna, Valencia, Spain. Electronic address: oscres@alumni.uv.es.
authors.forename: Oscar
authors.initials: O
authors.lastname: Crespo-Salvador
authors.affiliation: Laboratorio de Bioquímica y Biotecnología, Área de Fisiología Vegetal, Departamento de Ciencias Agrarias y del Medio Natural, ESTCE, Universitat Jaume I, 12071 Castellón, Spain. Electronic address: garciap@uji.es.
authors.forename: Pilar
authors.initials: P
authors.lastname: García-Agustín
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universidad de Valencia, IATA (CSIC), Avda Agustín Escardino 7, 46980 Paterna, Valencia, Spain. Electronic address: carmen.gonzalez@uv.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: González-Bosch
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D002480:Cellulase / Q000235:genetics* / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D008084:Lipoxygenase / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology; D044224:Pseudomonas syringae / Q000502:physiology*; D020156:Salicylic Acid / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D004269:DNA, Bacterial; C429844:KOR1 protein, Arabidopsis; D008565:Membrane Proteins; D054883:Oxylipins; C036483:T-DNA; C011006:jasmonic acid; C095864:lipoxygenase 3; D008084:Lipoxygenase; D002480:Cellulase; D020156:Salicylic Acid
keywords: Arabidopsis; Cell wall; Endo-glucanases; Plant response; Pseudomonas syringae