Circadian variation in Pseudomonas fluorescens (CHA0)-mediated paralysis of Caenorhabditis elegans

Authors
Romanowski, Andrés; Migliori, María Laura; Valverde, Claudio Fabián; Golombek, Diego Andrés
Publication Year
2011
Language
English
Format
article
Status
Published version
Description
Abiotic and biotic environmental stressors play a key role in the ecophysiology of most organisms. As the presence and activity of stress-inducing agents vary along the day, organisms that are able to predict these periodic changes are better fit to survive. Caenorhabditis elegans, a soil-dwelling nematode, is subjected to daily changes in its natural environment, and its tolerance to osmotic and oxidative stress varies along the day. Pseudomonas fluorescens strain CHA0 is a soil bacterium that produces a set of secondary metabolites that antagonize phytopathogenic fungi and therefore promote healthy growth of several plant species. Here we show that strain CHA0 is able to affect C. elegans either under growth limiting conditions (i.e., slow-killing) or by rapid paralysis in nutrient replete conditions (fast-killing). Both types of toxicity require the post-transcriptional Gac/Rsm regulatory cascade, and the fast paralytic killing depends strongly on hydrogen cyanide production. The response observed in C. elegans nematodes to fast paralytic killing varies along the day and its sensitivity is higher during the night, at Zeitgeber Time (ZT) 12 (lights off). This behavior correlates well with HCN tolerance, which is higher during the day, at ZT0 (lights on). The innate immune response to P. fluorescens CHA0 might depend on the stress response pathway of C. elegans. The fact that the tolerance varies daily gives further proof of an underlying clock that governs cyclic behavior in C. elegans. © 2010 Elsevier Ltd.
Fil: Romanowski, Andrés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Migliori, María Laura. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina
Fil: Valverde, Claudio Fabián. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina
Fil: Golombek, Diego Andrés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina
Subject
CAENORHABDITIS ELEGANS
CIRCADIAN RHYTHMS
CYANIDE
DAILY VARIATION
FAST PARALYTIC KILLING
PSEUDOMONAS
Otras Ciencias Biológicas
Ciencias Biológicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/53647