Faculty of Biology, University of Freiburg, Freiburg, Germany.
Science. 2012 Mar 16;335(6074):1348-51. doi: 10.1126/science.1218094.
Strigolactones, phytohormones with diverse signaling activities, have a common structure consisting of two lactones connected by an enol-ether bridge. Strigolactones derive from carotenoids via a pathway involving the carotenoid cleavage dioxygenases 7 and 8 (CCD7 and CCD8) and the iron-binding protein D27. We show that D27 is a β-carotene isomerase that converts all-trans-β-carotene into 9-cis-β-carotene, which is cleaved by CCD7 into a 9-cis-configured aldehyde. CCD8 incorporates three oxygens into 9-cis-β-apo-10'-carotenal and performs molecular rearrangement, linking carotenoids with strigolactones and producing carlactone, a compound with strigolactone-like biological activities. Knowledge of the structure of carlactone will be crucial for understanding the biology of strigolactones and may have applications in combating parasitic weeds.
独脚金内酯，一种具有多种信号活性的植物激素，具有由一个烯醇醚桥连接的两个内酯组成的共同结构。独脚金内酯通过涉及类胡萝卜素分裂双加氧酶 7 和 8（CCD7 和 CCD8）和铁结合蛋白 D27 的途径从类胡萝卜素衍生而来。我们表明，D27 是一种β-胡萝卜素异构酶，可将全反式-β-胡萝卜素转化为 9-顺式-β-胡萝卜素，CCD7 将其切割成 9-顺式醛。CCD8 将三个氧原子掺入 9-顺式-β-apo-10'-胡萝卜醛中，并进行分子重排，将类胡萝卜素与独脚金内酯连接起来，生成具有独脚金内酯样生物活性的化合物，即开环贝壳杉烯内酯。了解开环贝壳杉烯内酯的结构对于理解独脚金内酯的生物学特性至关重要，并且可能在防治寄生杂草方面具有应用价值。
