Zaxinone is an apocarotenoid regulatory metabolite required for normal rice growth and development. In addition, zaxinone has a large application potential in agriculture, due to its growth-promoting activity and capability to alleviate infestation by the root parasitic plant Striga through decreasing strigolactone (SL) production. However, zaxinone is poorly accessible to the scientific community because of its laborious organic synthesis that impedes its further investigation and utilization. In this study, we developed easy-to-synthesize and highly efficient mimics of zaxinone (MiZax). We performed a structure–activity relationship study using a series of apocarotenoids distinguished from zaxinone by different structural features. Using the obtained results, we designed several phenyl-based compounds synthesized with a high-yield through a simple method. Activity tests showed that MiZax3 and MiZax5 exert zaxinone activity in rescuing root growth of a zaxinone-deficient rice mutant, promoting growth, and reducing SL content in roots and root exudates of wild-type plants. Moreover, these compounds were at least as efficient as zaxinone in suppressing transcript level of SL biosynthesis genes and in alleviating Striga infestation under greenhouse conditions, and did not negatively impact mycorrhization. Taken together, MiZax are a promising tool for elucidating zaxinone biology and investigating rice development, and suitable candidates for combating Striga and increasing crop growth.

Zaxinone是正常水稻生长和发育所需的类胡萝卜素调节代谢产物。此外，zaxinone具有促进生长的能力和缓解根寄生植物Striga侵染的能力，因此在农业上具有广阔的应用潜力。通过减少strigolactone（SL）的产生。但是，由于它辛辛苦苦的有机合成阻碍了它的进一步研究和利用，因此科学界很难获得zaxinone。在这项研究中，我们开发了zaxinone（MiZax）的易于合成和高效的模拟物。我们进行了一系列结构-活性关系的研究，使用了一系列与zaxinone不同结构特征的类胡萝卜素。利用获得的结果，我们设计了一种通过简单方法以高收率合成的几种苯基基化合物。活性测试表明，MiZax3和MiZax5在挽救缺乏zaxinone的水稻突变体的根生长中发挥zaxinone活性，促进生长，并降低野生型植物根和根分泌物中的SL含量。此外，在温室条件下，Striga侵染不会对菌根形成产生负面影响。综上所述，MiZax是阐明zaxinone生物学和研究水稻发育的有前途的工具，也是抗击Striga和增加作物生长的合适候选人。