Lippincott B B, Margot J B, Lippincott J A
J Bacteriol. 1977 Dec;132(3):824-31. doi: 10.1128/jb.132.3.824-831.1977.
Avirulent strains IIBNV6 and NT1, derived from virulent strains of Agrobacterium tumefaciens, were tested for their ability to enhance tumor initiation (complement) on coinoculation with tumorigenic strains. Strain NT1, cured of the Agrobacterium virulence plasmid, failed to complement when inoculated with its virulent parental strain or with other virulent strains. Strain IIBNV6, however, complemented with all virulent strains tested. Attachment to host wound sites by both strain IIBNV6 and the virulent strain was essential for this effect. Inoculation of the tumorigenic strain at different times on leaves previously inoculated with IIBNV6 showed that the capacity to complement is lost during the period between 4 and 8 h after IIBNV6 inoculation. The rate of tumor appearance obtained with an inoculum containing IIBNV6 and a virulent auxotrophic strain was characteristic of the appearance rate obtained with prototrophic bacteria. Evidence is summarized which suggests that strain IIBNV6 can induce tumors when supplied with a substance produced or induced by a virulent bacterium at a separate site. A deoxyribonucleic acid plasmid about 40% the size of the Agrobacterium virulence plasmid was obtained from strain IIBNV6. We propose that this plasmid accounts for the ability of strain IIBNV6 to complement and that it contains part of the genetic information necessary for tumor initiation.
从根癌土壤杆菌的致病菌株衍生而来的无毒菌株IIBNV6和NT1，在与致瘤菌株共接种时，对其增强肿瘤起始（互补）的能力进行了测试。NT1菌株已去除土壤杆菌的毒性质粒，当与它的致病亲本菌株或其他致病菌株接种时，无法实现互补。然而，IIBNV6菌株与所有测试的致病菌株都能实现互补。IIBNV6菌株和致病菌株对宿主伤口部位的附着对于这种效应至关重要。在先前接种了IIBNV6的叶片上不同时间接种致瘤菌株，结果表明，在接种IIBNV6后4至8小时期间，互补能力丧失。含有IIBNV6和致病营养缺陷型菌株的接种物所获得的肿瘤出现率，与原养型细菌所获得的出现率特征相同。总结的证据表明，当在一个单独的位点提供由致病细菌产生或诱导产生的物质时，IIBNV6菌株能够诱导肿瘤。从IIBNV6菌株中获得了一个大小约为土壤杆菌毒性质粒40%的脱氧核糖核酸质粒。我们提出，该质粒解释了IIBNV6菌株的互补能力，并且它包含肿瘤起始所需的部分遗传信息。
