Arabidopsis histidine kinase 5 regulates salt sensitivity and resistance against bacterial and fungal infection

• Published in: The New phytologist Vol. 194; no. 1; pp. 168 - 180
• Main Authors: Pham, Jasmine, Liu, Jasmine, Bennett, Mark H., Mansfield, John W., Desikan, Radhika
• Format: Journal Article
• Language: English
• Published: Oxford, UK New Phytologist Trust 01.04.2012; Blackwell Publishing Ltd; Wiley Subscription Services, Inc
• Subjects: Arabidopsis; Arabidopsis - cytology; Arabidopsis - enzymology; Arabidopsis - immunology; Arabidopsis - microbiology; Arabidopsis histidine kinase 5; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Bacteria; Biological stress; Botrytis; Botrytis - drug effects; Botrytis - growth & development; Botrytis cinerea; Deoxyribonucleic acid; Disease Resistance - drug effects; DNA; Fungi; Histidine; Histidine Kinase; Homeostasis; Hormones; Infections; Kinases; Leaves; Lesions; Metabolism; Mutation - genetics; Oxidoreductions; Pathogens; Plant Diseases - microbiology; Plant growth; Plant growth regulators; Plant Growth Regulators - metabolism; Plants; Protein Kinases - metabolism; Pseudomonas syringae; Pseudomonas syringae - drug effects; Reactive oxygen species; Reactive Oxygen Species - metabolism; redox; Salinity; salt stress; Salts; Seedlings; Sensitivity; Signal transduction; Signaling; Sodium Chloride - pharmacology; Stomata; Stress; Stresses; Survival; Tomatoes
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2011.04033.x

The ability of plants to adapt to multiple stresses imposed by the natural environment requires cross-talk and fine-tuning of stress signalling pathways. The hybrid histidine kinase Arabidopsis histidine kinase 5 (AHK5) is known to mediate stomatal responses to exogenous and endogenous signals in Arabidopsis thaliana. The purpose of this study was to determine whether the function of AHK5 in stress signalling extends beyond stomatal responses. Plant growth responses to abiotic stresses, tissue susceptibility to bacterial and fungal pathogens, and hormone production and metabolism of reactive oxygen species were monitored in a T-DNA insertion mutant of AHK5. The findings of this study indicate that AHK5 positively regulates salt sensitivity and contributes to resistance to the bacterium Pseudomonas syringae pv. tomato DC3000 and the fungal pathogen Botrytis cinerea. This is the first report of a role for AHK5 in the regulation of survival following challenge by a hemi-biotrophic bacterium and a necrotrophic fungus, as well as in the growth response to salt stress. The function of AHK5 in regulating the production of hormones and redox homeostasis is discussed.