Manipulation of host gene expression by root-knot nematodes.

Root-knot nematodes (Meloidogyne spp.) establish elaborate feeding sites in their host. Unique patterns of gene expression are induced in root cells, resulting in formation of a novel cell type called a giant cell. Based on analysis of approximately 220 giant cell expressed genes, key elements of giant cell function and regulation have been identified; examples are discussed in the context of giant cell biology and ontogeny. The potential to effect nematode control by manipulating these genes in transgenic host plants is considered, and models for giant cell induction are presented.