Plant Lectins as Part of the Plant Defense System against Insects

During evolution plants have developed a wide range of sophisticated defense mechanisms to counteract attack by pathogens and herbivory. These include both mechanical and chemical defenses, and allow the plant to survive in the same environment as its potential attackers. As part of their chemical defense mechanism plants synthesize a whole battery of so-called defense proteins (Carlini and Grossi-de-S`a 2002). One particular class of defense proteins are the plant lectins, a heterogeneous group of proteins that can specifically interact with particular carbohydrates (Peumans and Van Damme 1995; Van Damme et al. 1998a, 2007b). This chapter will focus on the role of carbohydrate-bindingproteins (lectins) in plant defense against insects. A detailed discussion on the insecticidal activity of different families of carbohydratebinding proteins will be given. In addition, some recent results on inducible lectins involved in plant defense against insects will be discussed.