背景回顾：Maize (Zea mays) is a major staple crop in Africa, where its yield and the livelihood of millions are compromised by the parasitic witchweed Striga. Germination of Striga is induced by strigolactones exuded from maize roots into the rhizosphere. 

结果1-两个新的独脚金内酯：In a maize germplasm collection, we identified two strigolactones, zealactol and zealactonoic acid, which stimulate less Striga germination than the major maize strigolactone, zealactone. 

结果2-独脚金内酯合成酶：We then showed that a single cytochrome P450, ZmCYP706C37, catalyzes a series of oxidative steps in the maize-strigolactone biosynthetic pathway. 

结果3-P450酶的生物学功能：Reduction in activity of this enzyme and two others involved in the pathway, ZmMAX1b and ZmCLAMT1, can change strigolactone composition and reduce Striga germination and infection. 

结论：These results offer prospects for breeding Striga-resistant maize.

Reactions from CL to zealactol and ZA catalyzed by ZmCYP706C37 and ZmMAX1b.

玉米在非洲是主要的粮食作物，然而寄生植物独脚金危害了玉米的产量和数百万人的生计。玉米根部分泌到根际的独脚金内酯能够诱导独脚金的萌发。作者通过对玉米种质资源圃的筛选，鉴定到了两个新的独脚金内酯，即zealactol和zealactonoic acid，相比于最主要的玉米独脚金内酯zealactone，这两个新的独脚金内酯对于独脚金的萌发刺激更小。接着，作者发现细胞色素P450酶ZmCYP706C37催化玉米独脚金内酯生物合成途径中的一系列氧化反应。ZmCYP706C37酶和其它两个酶（ZmMAX1b和ZmCLAMT1）的活性降低会改变玉米根部分泌到根际的独脚金内酯组成，降低对独脚金的萌发刺激以及独脚金对于玉米植株的寄生。本文的研究结果为玉米的抗独脚金育种提供了新的视野。

** H. J. BOUWMEESTER **