Study on host-recognition mechanism of root parasitic weeds

对不同寄主的根寄生杂草产生的发芽刺激物进行了研究。例如，大豆和拟南芥被发现可以产生角凤尾鱼。此外，采用新开发的LC/MS/MS方法定量分析了红三叶草根生产环凤尾鱼的含量。一些寄主，包括番茄、豌豆和高粱，被发现产生新型的独角酯内酯。ACC合成酶和ACC氧化酶基因均从小矮脚山鸡中克隆而来，虽然小矮脚山鸡ACC氧化酶基因与其他植物基因同源性较高，但小矮脚山鸡ACC合成酶基因在其n端含有多个终止密码子，因此可能不具有功能。在O. Minor的细胞壁降解酶中，β -葡萄糖苷酶含量最多。该酶可能通过降解细胞壁和抑制宿主防御系统渗透到宿主根部。

Germination stimulants produced by various hosts of root parasitic weeds have been examined. For example, soybean and Arabidopsis were found to produce orobanchol. In addition, production of orobanchol by red clover roots has been quantified by a newly developed LC/MS/MS method. Some hosts, including tomato, pea, and sorghum were found to produce novel strigolactones. ACC synthase and ACC oxidase genes were cloned from Orobanche minor, Although Orobanche ACC oxidase gene had a high homology with genes from other plants, Orobanche ACC synthase gene contained several stop codons in its N-terminal region and thus may not be functional. Among cell wall degrading enzymes of O. Minor, beta-glucosidase was most abundant. This enzyme may be involved in penetration into host roots by degrading cell walls and also by inhibiting host defense system.