It is proposed to investigate scent production in Clarkia, a genus of annual plants native to California. Clarkia breweri is the only species in the genus with scented flowers. C. breweri flowers are visited mostly by hawkmoths. The odorless flowers of C. concinna, a closely related species, are visited mostly by butterflies and flies, whereas all other outcrossing Clarkia species are pollinated by bees. We have identified four major components of the scent of C. breweri flowers. They are linalool, linalool oxide, benzyl acetate, and methyl salicylate, all important ingredients in manufactured perfumes. We propose to conduct a formal genetic study of the genes controlling the production of these compounds in C. breweri, and to use molecular biological techniques to isolate the gene encoding the enzyme linalool synthase (LS) that catalyzed the synthesis of linalool. The genetic changes underlying the ability of C. breweri to make linalool, while its close relatives do not, will be examined. %%% Flower scents have profound effects on the reproduction of plants and are also important in many man-made products. However, the synthesis of flower scents has been scarcely investigated on the genetic and molecular level and the results obtained from this work will produce significant insights into this process.
