Glandular trichome-based insect

We have been involved in mechanistic studies aimed at understanding the basis of glandular trichome-based insect resistance in wild Solarium (potato) and Lycopersicon (tomato) species. Much effort has focused on identification of wild members of the Solanaceae with potentially useful resistance traits for introgression into Solarium tuberosum and Lycopersicon esculentum. In many cases resistance has been shown to be conferred by glandular trichomes, modified epidermal cells (i) which function as physical and/or chemical barriers against insect attack (2-10 > Tingey, this volume). 

The wild tomato, Lycopersicon pennellii, and the wild potato, Solanum berthaultiif are two species which exhibit insect resistance conferred by glandular trichomes. S, berthaultii and L. pennellii have been the focus of efforts at Cornell University to transfer trichome-based insect resistance traits. This chapter reviews our knowledge of the biochemistry of glandular trichome-based insect resistance in these species. 

Because 2-tridecanone-mediated resistance to sexta and L. decemlineata is genetically distinct from the lamellar-based resistance to zea, it would be possible to develop tomato cultivate resistant to sexta and decemlineata but susceptible to zea. On such cultivate, the 2-tridecanone-mediated induction of elevated tolerance to some insecticides might make control of zea more difficult (55, 58). The severity of H. zea as a pest problem on such cultivate would be further exacerbated if 2-tridecanone associated with the resistant foliage seriously interfered with insect parasitoids and predators important in suppressing natural populations of zea. Because of its occurrence in the foliar glandular trichomes, and because of its broad spectrum toxicity to insects, we considered it likely that parasitoids and predaceous insects searching the resistant foliage for prey would be exposed to potentially toxic levels of 2-tridecanone. 

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