美国宾夕法尼亚大学的研究人员从番茄中鉴定出两个新基因，它们在单萜生产中必不可少。单萜是一类化合物家族，在植物中用于授粉、抵御害虫和防御疾病。单萜还能赋予植物特有的味道，一些叶子的香味，如薄荷和罗勒，就来自于萜烯。

　　科学家一直以为植物用一种特殊化合物geranyl  diphosphate来生产单萜，而Robert  Last及其同事发现番茄用neryl  diphosphate作为底物，他们鉴定出两个新的酶：neryl  diphosphate合酶1（NDPS1）和phellandrene合酶1(PHS1)。

　　科学家认为这一发现有助于在其他植物中寻找相似基因并发现合成单萜的新酶，这样可能对植物抗虫有帮助。

　　推荐原始出处：

　　PNAS June 30, 2009 vol. 106 no. 26 10865-10870

　　Monoterpenes in the glandular trichomes of tomato are synthesized from a neryl diphosphate precursor rather than geranyl diphosphate

　　Anthony L. Schilmillera,1, Ines Schauvinholdb,1, Matthew Larsonc, Richard Xub, Amanda L. Charbonneaua, Adam Schmidtb, Curtis Wilkersona,d, Robert L. Lasta,d and Eran Picherskyb,2

　　We identified a cis-prenyltransferase gene, neryl diphosphate synthase 1 (NDPS1), that is expressed in cultivated tomato (Solanum lycopersicum) cultivar M82 type VI glandular trichomes and encodes an enzyme that catalyzes the formation of neryl diphosphate from isopentenyl diphosphate and dimethylallyl diphosphate. mRNA for a terpene synthase gene, phellandrene synthase 1 (PHS1), was also identified in these glands. It encodes an enzyme that uses neryl diphosphate to produce β-phellandrene as the major product as well as a variety of other monoterpenes. The profile of monoterpenes produced by PHS1 is identical with the monoterpenes found in type VI glands. PHS1 and NDPS1 map to chromosome 8, and the presence of a segment of chromosome 8 derived from Solanum pennellii LA0716 causes conversion from the M82 gland monoterpene pattern to that characteristic of LA0716 plants. The data indicate that, contrary to the textbook view of geranyl diphosphate as the “universal” substrate of monoterpene synthases, in tomato glands neryl diphosphate serves as a precursor for the synthesis of monoterpenes.