Study on host-recognition mechanism of root parasitic weeds

本文研究了根寄生杂草的不同寄主产生的发芽促进剂。例如，发现大豆和拟南芥产生列当醇。此外，生产列当酚的红三叶草根已被量化的新开发的LC/MS/MS方法。番茄、豌豆和高粱等寄主植物都能产生新的独脚金内酯。从列当中克隆了ACC合酶和ACC氧化酶基因，虽然列当ACC氧化酶基因与其它植物的基因具有很高的同源性，但列当ACC合酶基因在其N端含有多个终止密码子，可能不具有功能。在O.次要的β-葡萄糖苷酶含量最丰富。这种酶可能通过降解细胞壁和抑制宿主防御系统参与渗透到宿主根部。

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.