Root-knot nematode, Meloidogyne spp. (Fig. 1a) induces stereotypical giant cells in host roots (Fig. 1b). Using a subtractive cDNA cloning approach, we previously identified 197 tomato genes expressed in giant cells; these sequences are available in GenBank. Because these genes are not expressed in healthy roots, we used an informatics approach to establish their expression profile in tomato.
||Figure 1a. Newly hatched M. incognita larva. |
S: feeding stylet;
arrows: lipid storage granules.
|Figure 1b. Toluidine blue stained trans-verse section of a root-knot nematode gall in tomato; four giant cells are evident.