Biochemical investigations of antibiosis material in leaf exudate of wildNicotiana species and interspecific hybrids.

A model system involving severalNicotiana species containing novel nicotine alkaloids was used to study heritability and expression of alkaloid production in leaf trichomes. The three species that comprise the section Repandae (N. repanda, N. stocktonii, andN. nesophila) were hybridized with eitherN. tabacum orN. sylvestris (neither of which producesN-acylnornicotine). The progeny of the hybrid with sylvestris produced theN-acylnornicotines at a level found in the Repandae parent.Nicotiana repanda was crossed toN. tabacum, and the F2 progeny produced the alkaloid at the same level as the original Repandae parent. Inheritance of the ability to acylate nornicotine in Repandae species is inherited in hybrids in a dominant manner These and other data obtained suggest that theN-acyltransferase that acylates nornicotine in Repandae species inherited in hybrids is in a dominant manner and that the regulatory sequence(s) for the gene is expressed in leaf trichomes when the gene is in a foreignNicotiana background.