Salicylic acid as a defense-related plant hormone roles of oxidative and calcium signaling paths in salicylic acid biology

Abstract

Salicylic acid (SA) is a natural signaling molecule involved in plant defense response against pathogen infection. This chapter covers the recent progress in our understanding of the SA biology in plants, especially the signaling pathways and mechanisms by which SA performs its role as defense inducer are highlighted. The topics related to SA signal transduction covered here include (1) general biological roles played by SA; (2) biosynthesis, storage and translocation of SA; (3) oxidative SA metabolisms regulating the SA actions; (4) roles of reactive oxygen species and calcium ion in SA signaling paths; (5) the link between oxidative burst and other signaling paths; and (6) regulation of gene expression. Lastly, we illustrated the key signaling networks that coordinately lead to both early and late phases of SA-induced gene expression.