• Eupatorium adenophorum is a malignant invasive plant possessing extraordinary defense potency, but its chemical weaponry and formation mechanism have not yet been extensively investigated.
• We identified six cadinene sesquiterpenes, including two volatiles (amorpha‐4,7(11)‐diene and (–)‐amorph‐4‐en‐7‐ol) and four nonvolatiles (9‐oxo‐10,11‐dehydroageraphorone, muurol‐4‐en‐3,8‐dione, 9‐oxo‐ageraphorone and 9β‐hydroxy‐ageraphorone), as the major constitutive and inducible chemicals of E. adenophorum. All cadinenes showed potent antifeedant activity against a generalist insect Spodoptera exigua, indicating that they have significant defensive roles.
• We cloned and functionally characterized a sesquiterpene synthase from E. adenophorum (EaTPS1), catalyzing the conversion of farnesyl diphosphate to amorpha‐4,7(11)‐diene and (–)‐amorph‐4‐en‐7‐ol, which were purified from engineered Escherichia coli and identified by extensive nuclear magnetic resonance (NMR) spectroscopy. EaTPS1 was highly expressed in the aboveground organs, which was congruent with the dominant distribution of cadinenes, suggesting that EaTPS1 is likely involved in cadinene biosynthesis. Mechanical wounding and methyl jasmonate negatively regulated EaTPS1 expression but caused the release of amorpha‐4,7(11)‐diene and (–)‐amorph‐4‐en‐7‐ol. Nicotiana benthamiana transiently expressing EaTPS1 also produced amorpha‐4,7(11)‐diene and (–)‐amorph‐4‐en‐7‐ol, and showed enhanced defense function.
• The findings presented here uncover the role and formation of the chemical defense mechanism of E. adenophorum – which probably contributes to the invasive success of this plant – and provide a tool for manipulating the biosynthesis of biologically active cadinene natural products.

中文翻译：

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防御性cadinenes和负责其生物合成从入侵紫茎兰的新型倍半萜合酶的表征。

• 紫茎泽兰是具有非凡防御能力的恶性入侵植物，但其化学武器和形成机理尚未得到广泛研究。
• 我们确定了6个卡丁烯倍半萜，其中包括2种挥发物（amorpha-4,7（11）-diene和（–）-amorph-4-en-7-ol）和4种非挥发物（9 - oxo -10,11-dehydroageraphorone，muurol ‐4‐en‐3,8‐dione，9‐ oxo ‐AGEraphorone和9β‐hydroxy‐ageraphorone）是紫茎泽兰的主要组成成分和诱导型化学物质。所有的cadines表现出对普通昆虫天蛾（Spodoptera exigua）的强效拒食活性，表明它们具有重要的防御作用。
• 我们克隆并从功能上表征了紫茎泽兰的倍半萜烯合酶（EaTPS1），催化法呢基二磷酸转化为amorpha‐4,7（11）‐diene和（–）‐ amorph‐4‐en‐7‐ol，它们是从工程大肠杆菌中纯化并通过广泛的核磁共振（NMR）光谱鉴定。EaTPS1在地上器官中高度表达，这与cadinenes的主要分布是一致的，这表明EaTPS1可能参与了卡丁烯的生物合成。机械伤和茉莉酸甲酯对EaTPS1表达负调控，但导致了amorpha-4,7（11）-diene和（-）-amorph-4-4-en-7-ol的释放。烟草本氏烟草瞬时表达EaTPS1还产生了amorpha-4,7（11）-diene和（–）-amorph-4-4-en-7-ol，并显示出增强的防御功能。
• 此处提出的发现揭示了紫茎泽兰的化学防御机制的作用和形成-可能有助于该植物的入侵成功-并提供了操纵生物活性卡丁烯天然产物生物合成的工具。