Molecular Biology of Flower Scents

有人建议调查原产于加利福尼亚州的一年生植物克拉基亚的香味产生情况。克拉基亚是该属中唯一开有芳香花朵的物种。黄曲霉的花主要是由鹰蛾访问的。Cancinna是一种近缘关系密切的物种，其无味的花朵主要由蝴蝶和苍蝇访问，而所有其他异交的Carkia物种都是由蜜蜂授粉。我们已经确定了酿酒花香的四种主要成分。它们是芳樟醇、氧化芳樟醇、乙酸苄酯和水杨酸甲酯，这些都是人造香水的重要成分。我们建议对控制这些化合物在酿酒酵母中产生的基因进行正式的遗传学研究，并利用分子生物学技术来分离编码催化芳樟醇合成的芳樟醇合成酶(LS)的基因。研究人员将对酿酒酵母制造芳樟醇能力的遗传变化进行研究，而其近亲则不会。花香对植物的繁殖有深远的影响，在许多人造产品中也很重要。然而，鲜有人在遗传和分子水平上研究花香的合成，从这项工作中获得的结果将对这一过程产生重要的见解。

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.