• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.253-260
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• 2000

The virulence(vir) genes in Ti plasmid at Agrobacterium tumefaciens are expressed by a phenolic compound synthesized at plant wound site. The vir genes inducing abilities of 8 phenolic compounds were tested using three wild type strains of A. tumefaciens. It was also investigated how the levels of vir gene expression among the strains tested could be related to the kinds of specific phenolic compounds. Five phenolic compounds like as 4-hydroxyacetophenone, phenol, catechol, resorcinol, and vanillin had exhibited a strong effect on the vir gene expression of A. tumefaciens MW102 whereas they did not be either non-functional or weakly inducible to the vir gene expression of other strains i.e. A. tumefaciens MW105 and MW108. Furthermore, the vir gene of A. tumefaciens MW102 was lowly expressed by acetosyringone that exposed an strong effect on the vir gene induction of other two strains. Thus, it appeared that the vir gene inducing abilities were differed by the kinds of phenolic compounds and Ti plasmids. In conclusion, we suppose that a change in vir gene inducing ability could be resulted from a difference of sensor protein expressed by vir A gene.