Strigolactones initiate the formation of haustorium-like structures in <em>Castilleja</em>

Strigolactones serve as germination signals for several root-parasitic plant species within the Orobanchaceae family. Yet, their role in the life cycle of the facultatively parasitic genus has remained elusive. Here, we demonstrate that strigolactones initiate the formation of haustorium-like structures in . We present the genome of , which reveals an abundance of KAI2d paralogs that act as strigolactone receptors. ’s KAI2d proteins include high-turnover enzymes, in particular KAI2d15, which features a substrate binding pocket with a methionine cluster at its entrance that is involved in the trade-off between substrate turnover and affinity. Our findings provide insights into strigolactone perception in and refine our perspective on their role in facultative parasitism.Plant biology; Plant Genetics; Plant physiology

独脚金内酯作为列当科（Orobanchaceae）内几种根寄生植物物种的萌发信号。然而，它们在兼性寄生属植物生命周期中的作用仍然难以捉摸。在此，我们证明独脚金内酯在（此处缺失植物属名）中启动吸器状结构的形成。我们展示了（此处缺失植物属名）的基因组，其揭示了大量作为独脚金内酯受体的KAI2d旁系同源物。（此处缺失植物属名）的KAI2d蛋白包括高周转率的酶，特别是KAI2d15，它在其入口处具有一个带有甲硫氨酸簇的底物结合口袋，该口袋参与底物周转率和亲和力之间的权衡。我们的研究结果为（此处缺失植物属名）中独脚金内酯的感知提供了见解，并完善了我们对其在兼性寄生中作用的认识。植物生物学；植物遗传学；植物生理学