Hexanoic acid is a resistance inducer that protects tomato plants against Pseudomonas syringae by priming the jasmonic acid and salicylic acid pathways

• Published in: Molecular plant pathology Vol. 14; no. 4; pp. 342 - 355
• Main Authors: Scalschi, Loredana, Vicedo, Begonya, Camañes, Gemma, Fernandez-Crespo, Emma, Lapeña, Leonor, González-Bosch, Carmen, García-Agustín, Pilar
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01-05-2013; Blackwell; John Wiley & Sons, Inc; John Wiley and Sons Inc
• Subjects: Abscisic Acid - metabolism; Acids; Agronomy. Soil science and plant productions; Amino Acids - pharmacology; Bacterial plant pathogens; Biological and medical sciences; Biosynthetic Pathways - drug effects; Biosynthetic Pathways - genetics; Caproates - pharmacology; Cyclopentanes - metabolism; Disease Resistance - drug effects; Flowers & plants; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant - drug effects; Glucans - metabolism; Indenes - pharmacology; Lycopersicon esculentum; Original; Oxylipins - chemistry; Oxylipins - metabolism; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Growth Regulators - metabolism; Plant Proteins - biosynthesis; Plant Proteins - genetics; Plant Stomata - drug effects; Plant Stomata - physiology; Pseudomonas syringae; Pseudomonas syringae - drug effects; Pseudomonas syringae - physiology; Salicylic Acid - metabolism; Signal Transduction - drug effects; Signal Transduction - genetics; Solanum lycopersicum - drug effects; Solanum lycopersicum - immunology; Solanum lycopersicum - metabolism; Solanum lycopersicum - microbiology; Studies; Water - pharmacology; Pseudomonadales; Terpenoid; Salicylic acid; Plant pathogen; Hexanoic acid; Resistance; Vegetable crop; Saturated fatty acid; Pseudomonas syringae; Dicotyledones; Angiospermae; Lycopersicon esculentum; Bacteria; Pseudomonadaceae; Plant growth substance; Spermatophyta; Solanaceae; Jasmonic acid
• ISSN: 1464-6722; 1364-3703
• DOI: 10.1111/mpp.12010

Summary
Hexanoic acid‐induced resistance (Hx‐IR) is effective against several pathogens in tomato plants. Our study of the mechanisms implicated in Hx‐IR against Pseudomonas syringae pv. tomato DC3000 suggests that hexanoic acid (Hx) treatment counteracts the negative effect of coronatine (COR) and jasmonyl‐isoleucine (JA‐Ile) on the salicylic acid (SA) pathway. In Hx‐treated plants, an increase in the expression of jasmonic acid carboxyl methyltransferase (JMT) and the SA marker genes PR1 and PR5 indicates a boost in this signalling pathway at the expense of a decrease in JA‐Ile. Moreover, Hx treatment potentiates 12‐oxo‐phytodienoic acid accumulation, which suggests that this molecule might play a role per se in Hx‐IR. These results support a positive relationship between the SA and JA pathways in Hx‐primed plants. Furthermore, one of the mechanisms of virulence mediated by COR is stomatal re‐opening on infection with P. syringae. In this work, we observed that Hx seems to inhibit stomatal opening in planta in the presence of COR, which suggests that, on infection in tomato, this treatment suppresses effector action to prevent bacterial entry into the mesophyll.