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: Jaime López-Cruz, Ivan Finiti, Emma Fernández-Crespo, Oscar Crespo-Salvador, Pilar García-Agustín, Carmen González-Bosch
• Journal: Journal of plant physiology (J Plant Physiol) Vol. 171 Issue 16 Pg. 1524-32 (Oct 15 2014) ISSN: 1618-1328 [Electronic] Germany
• PMID: 25108263 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier GmbH. All rights reserved.

Chemical References

• Arabidopsis Proteins
• Cyclopentanes
• DNA, Bacterial
• KOR1 protein, Arabidopsis
• Membrane Proteins
• Oxylipins
• T-DNA
• jasmonic acid
• lipoxygenase 3
• Lipoxygenase
• Cellulase
• Salicylic Acid

Topics

• Arabidopsis (genetics, metabolism)
• Arabidopsis Proteins (genetics, metabolism)
• Cell Wall (metabolism)
• Cellulase (genetics, metabolism)
• Cyclopentanes (metabolism)
• DNA, Bacterial (genetics)
• Gene Expression Regulation, Plant
• Lipoxygenase (genetics, metabolism)
• Membrane Proteins (genetics, metabolism)
• Oxylipins (metabolism)
• Plant Diseases (microbiology)
• Pseudomonas syringae (physiology)
• Salicylic Acid (metabolism)