Dual role of auxin in regulating plant defense and bacterial virulence gene expression duringPseudomonas syringae PtoDC3000 pathogenesis
| Autor: | Gregory A. Harrison, Arnaud T. Djami-Tchatchou, Christopher P. Harper, Renhou Wang, Barbara N. Kunkel, Michael J. Prigge, Mark Estelle |
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| Rok vydání: | 2019 |
| Předmět: |
Physiology
Mutant Arabidopsis Pseudomonas syringae Plant Biology chemistry.chemical_compound Gene expression Plant defense against herbivory 2.1 Biological and endogenous factors 2.2 Factors relating to the physical environment Arabidopsis thaliana Plant Immunity heterocyclic compounds Aetiology Pathogen 2. Zero hunger chemistry.chemical_classification 0303 health sciences Virulence biology pathogenesis virulence gene expression food and beverages General Medicine Cell biology Infectious Diseases host defense Plant hormone Salicylic Acid Infection Signal Transduction auxin signaling Biotechnology Plant Biology & Botany Microbiology 03 medical and health sciences Auxin Genetics Plant Diseases 030304 developmental biology Indoleacetic Acids 030306 microbiology fungi Plant biology.organism_classification Emerging Infectious Diseases Gene Expression Regulation chemistry Mutation indole-3-acetic acid Indole-3-acetic acid Agronomy and Crop Science |
| Zdroj: | Molecular plant-microbe interactions : MPMI, vol 33, iss 8 |
| Popis: | Modification of host hormone biology is a common strategy used by plant pathogens to promote disease. For example, the bacterial pathogenPseudomonas syringaestrainPtoDC3000 produces the plant hormone auxin (Indole-3-acetic acid, or IAA) to promotePtoDC3000 growth in plant tissue. Previous studies suggest that auxin may promotePtoDC3000 pathogenesis through multiple mechanisms, including both suppression of salicylic acid (SA)-mediated host defenses and via an unknown mechanism that appears to be independent of SA. To test if host auxin signaling is important during pathogenesis, we took advantage ofArabidopsis thalianalines impaired in either auxin signaling or perception. We found that disruption of auxin signaling in plants expressing an inducible dominantaxr2-1mutation resulted in decreased bacterial growth, demonstrating that host auxin signaling is required for normal susceptibility toPtoDC3000, and this phenotype was dependent on SA-mediated defenses. However, despite exhibiting decreased auxin perception,tir1 afb1 afb4 afb5quadruple mutant plants lacking four of the six known auxin co-receptors supported increased levels of bacterial growth. This mutant also exhibited elevated IAA levels, suggesting that the increased IAA in these plants may promotePtoDC3000 growth independent of host auxin signaling, perhaps through a direct effect on the pathogen. In support of this, we found that IAA directly impacted the pathogen, by modulating expression of bacterial virulence genes, both in liquid culture and in planta. Thus, in addition to suppressing host defenses, IAA acts as a microbial signaling molecule that regulates bacterial virulence gene expression. |
| Databáze: | OpenAIRE |
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