Sounding the Alarm: Signaling and Communication in Plant Defense

Abstract

Each of the approximately 300,000 plant species present on Earth is attacked by a multitude of other organisms. As we saw in the previous chapter, plants have evolved an arsenal of physical and chemical weapons and barriers to tackle this assault. The question for plants is, how and when to unleash these defenses? In other words, how do plants perceive these threats, and further, how do they translate that perception into the appropriate action? In the sections below, we look at the signaling pathways responsible for regulating plant defenses to the range of different attackers encountered by plants. We examine the signals involved in regulating defenses within the tissue being attacked, and the signals involved in alerting other plant tissues not yet under attack. We also look at the evidence for communicating these threats to neighboring plants.