Phytopathology. 1999 Apr;89(4):286-92. doi: 10.1094/PHYTO.1999.89.4.286.
ABSTRACT The behavior of the virulent transconjugant K84N6 derived from Agrobacterium radiobacter strain K84 after spontaneous Ti plasmid transfer in crown gall tissue in a biocontrol experiment was studied and compared with the behavior of the wild-type A. tumefaciens donor of the Ti plasmid. The main difference between the strains was a greatly reduced ability of the transconjugant to catabolize nopaline. Host range, ability to induce tumors in several fruit trees, and stability of the pathogenic determinants in isolates from tumors did not differ between the strains. Nevertheless, in a biocontrol experiment, the transconjugant was not controlled by strain K84 or K1026 in peach x almond hybrids and survived in the plant rhizo-sphere for 9 months with larger population densities than the wild strain. The appearance and persistence in soil of strains harboring a Ti plasmid in the K84 chromosomal background could represent a risk in the medium term, if they show good competitive ability.
摘要 本研究对源于根癌农杆菌 K84 菌株的毒性接合转移子 K84N6 在冠瘿组织中自发 Ti 质粒转移后的行为进行了研究，并与 Ti 质粒野生型供体 A. tumefaciens 的行为进行了比较。这两种菌株的主要区别在于，接合转移子对胭脂碱的分解能力大大降低。宿主范围、在几种果树上诱导肿瘤的能力以及从肿瘤分离物中致病性决定因素的稳定性在两种菌株之间没有差异。然而，在生物防治实验中，在桃 x 巴旦杏杂种中，该接合转移子不受 K84 或 K1026 菌株的控制，并且在植物根际中存活了 9 个月，其种群密度大于野生菌株。如果这些携带 Ti 质粒的菌株具有良好的竞争能力，那么它们在 K84 染色体背景中出现并在土壤中持续存在可能是一个中期风险。
