title: Diuretics prime plant immunity in Arabidopsis thaliana.
abstract: Plant activators are agrochemicals that activate the plant immune system, thereby enhancing disease resistance. Due to their prophylactic and durable effects on a wide spectrum of diseases, plant activators can provide synergistic crop protection when used in combination with traditional pest controls. Although plant activators have achieved great success in wet-rice farming practices in Asia, their use is still limited. To isolate novel plant activators applicable to other crops, we screened a chemical library using a method that can selectively identify immune-priming compounds. Here, we report the isolation and characterization of three diuretics, bumetanide, bendroflumethiazide and clopamide, as immune-priming compounds. These drugs upregulate the immunity-related cell death of Arabidopsis suspension-cultured cells induced with an avirulent strain of Pseudomonas syringae pv. tomato in a concentration-dependent manner. The application of these compounds to Arabidopsis plants confers disease resistance to not only the avirulent but also a virulent strain of the pathogen. Unlike salicylic acid, an endogenous phytohormone that governs disease resistance in response to biotrophic pathogens, the three diuretic compounds analyzed here do not induce PR1 or inhibit plant growth, showing potential as lead compounds in a practical application.
authors.affiliation: Research Core for Interdisciplinary Sciences, Okayama University, Kita-ku, Okayama, Japan. noutoshi@cc.okayama-u.ac.jp
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Noutoshi
authors.forename: Mika
authors.initials: M
authors.lastname: Ikeda
authors.forename: Ken
authors.initials: K
authors.lastname: Shirasu
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000276:immunology* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics; D001539:Bendroflumethiazide / Q000737:chemistry / Q000494:pharmacology; D002034:Bumetanide / Q000737:chemistry / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D003005:Clopamide / Q000737:chemistry / Q000494:pharmacology; D060467:Disease Resistance / Q000187:drug effects* / Q000235:genetics / Q000276:immunology; D004232:Diuretics / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D054884:Host-Pathogen Interactions / Q000187:drug effects / Q000276:immunology; D015394:Molecular Structure; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D057865:Plant Immunity / Q000187:drug effects* / Q000235:genetics; D044224:Pseudomonas syringae / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D004232:Diuretics; D014157:Transcription Factors; D002034:Bumetanide; C077262:PR-1 protein, Arabidopsis; D003005:Clopamide; D001539:Bendroflumethiazide