Fungal elicitor induces hypersensitive response and systemic oxidative burst in strawberry plants

CHALFOUN, NADIA REGINA; CASTAGNARO, ATILIO PEDRO; DIAZ RICCI, JUAN CARLOS

Pinamar. Argentina

Congreso; PABMB - 41º Annual Meeting SAIB; 2005

SAIB

The oxidative burst is one of the most rapid plant response to pathogen attack, and reactive oxygen species are considered to be essential for elicitation of other defense reactions. The oxidative burst, the generation of reactive oxygen species (ROS) in response to microbial pathogen attack, is a ubiquitous early part of the resistance mechanisms of plant cells. One of the earliest biochemical changes associated with the HR is an oxidative burst producing reactive oxygen intermediates (ROI), including superoxide anion (O2_) which can be dismutated rapidly to H2O2. The aim of the study was to analyze a production of two reactive oxygen species (ROS) (superoxide O2 -. and hydrogen peroxide H2O2) in response to fungal elicitor in strawberry plants. We show that inoculation of leaves with an elicitor rapidly induces secondary oxidative bursts in distant tissues and uninoculated leaves. Hence, the oxidative burst and are not confined to the macroscopic HR at the inoculation site but are reiterated at discrete microsites in distant tissues. The oxidative burst at the inoculation site induces these systemic cellular responses, and moreover, both the localized primary oxidative burst and the subsequent secondary microbursts in distant leaves. These findings demonstrate that ROIs mediate a reiterative signal network that underlies systemic as well as local resistance responses.