The Role of Terpene Synthases in Floral Scent Emission in Arabidopsis thaliana and Related Species

拟南芥是最重要的植物模式生物，其完整的基因序列现在已经知道。虽然一般认为A.虽然拟南芥花大多数是自花授粉的，但是我们已经发现，这些花散发出萜烯类化合物的香味挥发物，并且先前的报道确实表明，在自然界中确实发生了未确定水平的异花授粉。助理拟南芥基因组中有33个基因与已知的萜烯脱氢酶（TPSs）具有同源性，并且我们已经证明，在正常条件下，这些基因中的5个仅在花中表达，另外14个在花以及一些其它组织中表达。在这个项目中，Pichersky博士的实验室将描述A.不同环境下的拟南芥植株，分析花表达的TPS基因编码的酶的活性，详细检测TPS基因在整个植株中的组织特异性表达，鉴定A.我们还将对这种访问所造成的异花授粉情况进行评估。气味更明显的相关物种也将被比较。该项目是一个跨学科的研究花香的生物合成及其对异花授粉成功的影响，包括从分子生物学到生物化学到生态学的方法。这些结果将提供一个重要的植物生命特征，迄今为止很少了解详细的了解。这一新知识也将高度适用于作物，其中许多作物依赖于异花授粉来获得种子和果实。了解了嗅觉基因在A.拟南芥模式系统将有助于发现和操纵重要作物中的气味基因，以提高气味产生和吸引有益的传粉者。最后，该项目将在PI的实验室和正式课程中为研究生和本科生提供优秀的跨学科培训和教育，PI将继续向公众传播结果，并在科学期刊上发表报告。

Arabidopsis thaliana is the most important plant model organism, and the sequence of its entire complement of genes is now known. Although it is generally believed that A. thaliana flowers mostly self-pollinate, we have discovered that the flowers emit scent volatiles of the terpene class of compounds, and previous reports do suggest that an undetermined level of cross-pollination does occur in nature. The A. thaliana genome has 33 genes with homology to known terpene synthases (TPSs), and we have shown that under normal conditions, five of these genes are expressed exclusively in flowers, and 14 more are expressed in flowers as well as in some other tissues. In this project, Dr. Pichersky's lab will characterize the floral scent of A. thaliana plants from different environments, characterize the activity of the enzymes encoded by all the flower-expressed TPS genes, perform a detailed examination of the tissue-specific expression of these TPS genes throughout the plant, identify insect visitors to A. thaliana flowers, and estimate the level of cross-pollination caused by such visits. Related species that are more noticeably scented will also be compared. This project is an interdisciplinary investigation of the biosynthesis of floral scent and its effect on the success of cross-pollination, encompassing methods from molecular biology to biochemistry to ecology. The results will provide detailed understanding of an important plant life trait that has hitherto been little understood. This new knowledge will also be highly applicable to crop plants, many of which depend on cross-pollination for seed and fruit set. Knowing how scent genes are activated in the A. thaliana model system will facilitate the discovery and manipulation of scent genes in important crop plants to enhance scent production and attract beneficial pollinators. Finally, the project will provide excellent interdisciplinary training and education for graduate and undergraduate students both in the PI's lab and in formal courses, and the PI will continue to disseminate the results to the general public in addition to reports in scientific journals.