Glandular trichomes, known as metabolic cell factories, have been proposed as highly suitable for metabolically engineering the production of plant high-value specialized metabolites. Natural pyrethrins, found only in Dalmatian pyrethrum (Tanacetum cinerariifolium), are insecticides with low mammalian toxicity and short environmental persistence. Type I pyrethrins are esters of the monoterpenoid trans-chrysanthemic acid with one of the three rethrolone-type alcohols. To test if glandular trichomes can be made to synthesize trans-chrysanthemic acid, we reconstructed its biosynthetic pathway in tomato type VI glandular trichomes, which produce large amounts of terpenoids that share the precursor dimethylallyl diphosphate (DMAPP) with this acid. This was achieved by coexpressing the trans-chrysanthemic acid pathway related genes including TcCDS encoding chrysanthemyl diphosphate synthase and the fusion gene of TcADH2 encoding the alcohol dehydrogenase 2 linked with TcALDH1 encoding the aldehyde dehydrogenase 1 under the control of a newly identified type VI glandular trichome-specific metallocarboxypeptidase inhibitor promoter. Whole tomato leaves harboring type VI glandular trichomes expressing all three aformentioned genes had a concentration of total trans-chrysanthemic acid that was about 1.5-fold higher (by mole number) than the levels of β-phellandrene, the dominant monoterpene present in non-transgenic leaves, while the levels of β-phellandrene and the representative sesquiterpene β-caryophyllene in transgenic leaves were reduced by 96% and 81%, respectively. These results suggest that the tomato type VI glandular trichome is an alternative platform for the biosynthesis of trans-chrysanthemic acid by metabolic engineering.

腺毛，被称为代谢细胞工厂，被认为非常适合代谢工程化植物高价值特殊代谢物的生产。仅在达尔马提亚除虫菊 ( T​​anacetum cinerariifolium ) 中发现的天然除虫菊素是一种对哺乳动物毒性低且环境持久性短的杀虫剂。I型除虫菊酯是单萜类反式菊酸与三种rethrolone型醇之一的酯。测试腺毛是否可以合成反式-菊酸，我们在番茄VI型腺毛中重建了其生物合成途径，其产生大量与该酸共享前体二甲基烯丙基二磷酸（DMAPP）的萜类化合物。这是通过共表达反菊酸途径相关基因来实现的，包括编码菊二磷酸合酶的 TcCDS 和编码乙醇脱氢酶 2 的 TcADH2 的融合基因，该基因与编码醛脱氢酶 1 的TcALDH1在新发现的 VI 型腺毛状体的控制下连接。特异性金属羧肽酶抑制剂启动子。含有表达所有三个上述基因的 VI 型腺毛的整个番茄叶的总浓度为反式菊酸比β-水芹烯（存在于非转基因叶片中的主要单萜）的水平高约 1.5 倍（按摩尔数计） ，而β-水芹烯和转基因中的代表性倍半萜烯β-石竹烯的水平叶片分别减少了 96% 和 81%。这些结果表明，番茄VI型腺毛是通过代谢工程生物合成反式菊酸的替代平台。