Functional Defense Signals in Plants

Abstract

Plants live in a complex environment where they interact with a number of microbial pathogens with varying lifestyles and infection strategies. Numerous morphological, biochemical, and molecular mechanisms exist to cope with the effects of pathogen infection. Some mechanisms are preexisting and others induced upon infection of pathogens or attack of herbivores. Phytohormones have been shown to play key role in plant defense, and they mediate defense signaling cascades in plants. Phytohormones such as salicylic acid, jasmonic acid, and ethylene have been shown to play crucial role in the regulation of defense signaling. Understanding of function of complex defense signaling network is important. The present chapter is aimed to study about the role of phytohormones in induction of defense mechanism in plants. Moreover, this study covers the defense mechanisms (existing/induced) in the plants against the phytopathogens.