Induction of wound response gene expression in tomato leaves by ionophores.

Abstract

Three ionophores were used to investigate a potential role of the plasma-membrane (PM) potential in the regulation of systemic wound-response gene expression in tomato (Lycopersicon escuilentum Mill.) plants. Valinomycin, nigericin, and gramicidin, which affect the PM potential by dissipating H+ and K+ gradients, respectively, induced the rapid accumulation of wound-response gene transcripts. Transcript induction by gramicidin was kinetically, qualitatively and quantitatively similar to systemin-induced transcript accumulation. On a molar basis, gramicidin and nigericin, which affect gradients of both H+ and K+, were more effective than the K+-selective valinomycin. Hyperpolarization of the PM by fusicoccin, on the other hand, repressed wound-response gene expression and, at the same time, induced salicylic acid (SA) accumulation and the expression of pathogenesis-related proteins. We show here that the inhibition of the wound response after fusicoccin treatment is not mediated by elevated concentrations of SA but is likely a direct effect of PM hyperpolarization. The data indicate a role for the PM potential in the differential regulation of wound and pathogen defense responses.

• Authors: A Schaller, D Frasson
• Journal: Planta (Planta) Vol. 212 Issue 3 Pg. 431-5 (Feb 2001) ISSN: 0032-0935 [Print] Germany
• PMID: 11289608 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 2-aminoindan-2-phosphonic acid
• Glycosides
• Indans
• Ionophores
• Organophosphonates
• Plant Proteins
• Protease Inhibitors
• proteinase inhibitor II protein, plant
• Gramicidin
• Valinomycin
• fusicoccin
• proteinase inhibitor I (plants)
• RNA
• Leucyl Aminopeptidase
• Threonine Dehydratase
• Salicylic Acid
• Nigericin

Topics

• Cell Membrane (drug effects, physiology)
• Gene Expression Regulation, Plant (drug effects)
• Glycosides (pharmacology)
• Gramicidin (pharmacology)
• Indans
• Ionophores (pharmacology)
• Leucyl Aminopeptidase (biosynthesis, genetics)
• Solanum lycopersicum (drug effects, genetics, physiology)
• Membrane Potentials (drug effects)
• Nigericin (pharmacology)
• Organophosphonates (pharmacology)
• Plant Leaves (drug effects, genetics, physiology)
• Plant Proteins (biosynthesis, genetics)
• Protease Inhibitors (metabolism)
• RNA (analysis)
• Salicylic Acid (metabolism)
• Signal Transduction
• Threonine Dehydratase (biosynthesis, genetics)
• Transcription, Genetic (drug effects)
• Valinomycin (pharmacology)