Relationship between chloroplastic H2O2 and the salicylic acid response

Abstract

reactive oxygen species (roS) act as signaling molecules for regulating plant responses to abiotic and biotic stress and there exist source-and kind-specific pathways for roS signaling. recently, we created a novel system for producing H2O2 in Arabidopsis chloroplasts by chemical-dependent thylakoid membrane-bound ascorbate peroxidase (tAPX) silencing using an estrogen-inducible rnAi method. microarray analysis revealed that the expression of a large set of genes was altered in response to tAPX silencing, some of which are known to be involved in pathogen response/resistance. Furthermore, we found that tAPX silencing enhances the levels of salicylic acid (SA) and the response to SA, a central regulator for biotic stress response. in this addendum, we describe the relationship between chloroplastic H2O2 and SA in stress response, and discuss the function of the kind-and source-specific roS signaling in SA-mediated stress response. © 2012 Landes Bioscience.