Ralstonia solanacearum encounters an oxidative environment during tomato infection.

Imagen de Zomary Flores-Cruz
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TítuloRalstonia solanacearum encounters an oxidative environment during tomato infection.
Publication TypeJournal Article
Year of Publication2009
AutoresFlores-Cruz, Z, Allen, C
JournalMol Plant Microbe Interact
Volume22
Issue7
Pagination773-82
Date Published2009 Jul
ISSN0894-0282
Palabras claveGene Expression Regulation, Bacterial, Genes, Bacterial, Genome, Bacterial, Hydrogen Peroxide, Lycopersicon esculentum, Mutation, Oxidative Stress, Plant Diseases, Plant Leaves, Ralstonia solanacearum, Reactive Oxygen Species
Abstract

Ralstonia solanacearum genes that are induced during tomato infection suggested that this pathogen encounters reactive oxygen species (ROS) during bacterial wilt pathogenesis. The genomes of R. solanacearum contain multiple redundant ROS-scavenging enzymes, indirect evidence that this pathogen experiences intense oxidative stress during its life cycle. Over 9% of the bacterium's plant-induced genes were also upregulated by hydrogen peroxide in culture, suggesting that oxidative stress may be linked to life in the plant host. Tomato leaves infected by R. solanacearum contained hydrogen peroxide, and concentrations of this ROS increased as pathogen populations increased. Mutagenesis of a plant-induced predicted peroxidase gene, bcp, resulted in an R. solanacearum strain with reduced ability to detoxify ROS in culture. The bcp mutant caused slightly delayed bacterial wilt disease onset in tomato. Moreover, its virulence was significantly reduced on tobacco plants engineered to overproduce hydrogen peroxide, demonstrating that Bcp is necessary for detoxification of plant-derived hydrogen peroxide and providing evidence that host ROS can limit the success of this pathogen. These results reveal that R. solanacearum is exposed to ROS during pathogenesis and that it has evolved a redundant and efficient oxidative stress response to adapt to the host environment and cause disease.

DOI10.1094/MPMI-22-7-0773
Alternate JournalMol. Plant Microbe Interact.
PubMed ID19522559