ABSTRACT
Response of plants to fungal infection is accompanied by different types of cell death in various
plant-pathogen interactions. The types of cell death observed in plants during fungal patho-
genesis include programmed cell death (PCD) (Wang et al., 2005; Zuppini et al., 2005), hyper-
sensitive (¼ hypersensitive response (HR)-related) cell death (Dangl et al., 1996; Peterha¨nsel et al., 1997; Hu¨ckelhoven et al., 1999; Sasabe et al., 2000; Moeder et al., 2005; Montillet et al.,
2005), runaway cell death (RCD) (Jabs et al., 1996; Ruste´rucci et al., 2001), spontaneous cell
death (Peterha¨nsel et al., 1997; Dong, 2004; Brodersen et al., 2005), and normosensitive or
susceptibility-related cell death (¼ cell necrosis) (Kira´ly et al., 2002; Eckardt, 2005). Cell death and disease development are intimately connected. Cell death may be pheno-
typically associated with both susceptible and resistance interactions (Gilchrist, 1998; Dickman
et al., 2001; Greenberg and Yao, 2004; Eckardt, 2005; Takemoto et al., 2005). Whereas
hypersensitive cell death (HR cell death) is associated with disease resistance, normosensitive
cell death or cell death by necrosis is associated with susceptibility. Regulation of cell death
may be crucial to determine the outcome of plant-pathogen interactions, susceptibility, or
resistance. In either case, pathogen challenge can trigger groups of plant cells to die (Dickman
et al., 2001). Cell death in plants accompanies both susceptible and resistant reactions,
suggesting that overlapping biochemical pathways are operative in these two contrasting
outcomes. This chapter describes the cell death programs operative in both susceptible and
resistance interactions and their role in disease or resistance development.
