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剂进行了检测。例如，大豆和拟南芥被发现产生orobancol。此外，还利用新开发的LC/MS/MS方法对红三叶根部产生的罗班胆酚进行了定量。一些寄主，包括番茄、豌豆和高粱，被发现产生新的链霉内酯。本研究克隆了小花莲子ACC合成酶和ACC氧化酶基因，虽然该基因与其他植物的同源性较高，但其N-末端含有多个终止密码子，可能不具有功能。在小根霉细胞壁降解酶中，β-葡萄糖苷酶含量最高。这种酶可能通过降解细胞壁和抑制寄主防御系统而渗透到寄主根中。

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.