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Heterologous Expression of the Mi-1.2 Gene from Tomato Confers Resistance Against Nematodes but Not Aphids in Eggplant

April 2006 , Volume 19 , Number  4
Pages  383 - 388

Fiona L. Goggin , 1 Lingling Jia , 1 Gowri Shah , 2 Stephanie Hebert , 1 Valerie M. Williamson , 3 and Diane E. Ullman 4

1Department of Entomology, University of Arkansas, 320 Agriculture Building, Fayetteville, AR 72701, U.S.A.; 2DNA Plant Technologies, 6701 San Pablo Ave., Oakland, CA, 94608, U.S.A.; 3Department of Nematology, University of California, 1 Shields Ave., Davis, CA 95616, U.S.A.; 4Department of Entomology, University of California, 1 Shields Ave., Davis, CA 95616, U.S.A.

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Accepted 4 January 2006.

The Mi-1.2 gene in tomato (Solanum lycopersicum) is a member of the nucleotide-binding leucine-rich repeat (NB-LRR) class of plant resistance genes, and confers resistance against root-knot nematodes (Meloidogyne spp.), the potato aphid (Macrosiphum euphorbiae), and the sweet potato whitefly (Bemisia tabaci). Mi-1.2 mediates a rapid local defensive response at the site of infection, although the signaling and defensive pathways required for resistance are largely unknown. In this study, eggplant (S. melongena) was transformed with Mi-1.2 to determine whether this gene can function in a genetic background other than tomato. Eggplants that carried Mi-1.2 displayed resistance to the root-knot nematode Meloidogyne javanica but were fully susceptible to the potato aphid, whereas a susceptible tomato line transformed with the same transgene was resistant to nematodes and aphids. This study shows that Mi-1.2 can confer nematode resistance in another Solanaceous species. It also indicates that the requirements for Mi-mediated aphid and nematode resistance differ. Potentially, aphid resistance requires additional genes that are not conserved between tomato and eggplant.

Additional keywords: insect resistance, Lycopersicon esculentum, restricted taxonomic functionality.

© 2006 The American Phytopathological Society