Chicory (Cichorium intybus L.) is a medicinal and industrial plant from the Asteraceae family that produces a variety of sesquiterpene lactones (STLs), most importantly bitter guaianolides: lactucin, lactucopicrin and 8-deoxylactucin as well as their modified forms such as oxalates. These compounds have medicinal properties; however, they also hamper the extraction of inulin - a very important food industry product from chicory roots. The first step in guaianolide biosynthesis is catalyzed by germacrene A synthase (GAS) which in chicory exists in two isoforms - GAS long (encoded by CiGASlo) and GAS short (encoded by CiGASsh). AmiRNA silencing was used to obtain plants with reduced GAS gene expression and level of downstream metabolites, guaianolide-15-oxalates, as the major STLs in chicory. This approach could be beneficial for engineering new chicory varieties with varying STL content, and especially varieties with reduced bitter compounds more suitable for inulin production.

中文翻译：

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沉默germ草烯A合酶基因可减少菊苣中菊苣内酯的草酸内酯含量。

菊苣（菊苣）是菊科的药用和工业植物，可生产多种倍半萜烯内酯（STL），最重要的是苦瓜酚内酯：乳糖苷，乳酸苦味精和8-脱氧lactucin及其修饰形式，例如草酸盐。这些化合物具有药用特性。但是，它们也会阻碍菊粉的提取，菊粉是菊苣根中非常重要的食品工业产品。菊苣酯A合酶（GAS）催化菊苣酯生物合成的第一步，菊苣中存在两种同工型-长GAS（由CiGASlo编码）和GAS短（由CiGASsh编码）。使用AmiRNA沉默来获得具有降低的GAS基因表达和下游代谢物guaianolide-15-草酸盐水平的植物，作为菊苣中的主要STL。