Regarding the regulation of Vir gene expression by metabolites, the levels varied with the kind of plants, and the regulatory responses of various Vir loci to extracts or exudates varied with not only different sources but even the fame one.

• 其调节水平随植物的不同而明显不同,但单、双子叶植物的代谢物对Vir基因表达的调节作用并非截然分开。