Ohyama K, Pelcher L E, Schaefer A
National Research Council of Canada, Prairie Regional Laboratory, Saskatoon, Saskatchewan, S7K 0W9 Canada.
Plant Physiol. 1979 Feb;63(2):382-7. doi: 10.1104/pp.63.2.382.
In vitro binding experiments were carried out using (32)P-labeled cells of the virulent Agrobacterium tumefaciens strain B6 and Datura innoxia cells from suspension culture. Binding kinetics showed that adherence of bacteria to Datura cells increased gradually during the first 60 minutes and attained a maximum level within 120 minutes of incubation. Maximum binding occurred at pH 6.0. The presence of Ca(2+) and Mg(2+) reduced binding slightly and EDTA had little effect at concentrations of 0.1 to 10 millimolar. The binding of bacteria to Datura cells was temperature-dependent. Escherichia coli, Salmonella typhimurium, Rhizobium japonicum, and Micrococcus lysodeikticus did not compete with virulent A. tumefaciens strain B6 for binding to Datura cells. The admixture of avirulent A. tumefaciens strain IIBNV6 enhanced adherence of virulent A. tumefaciens strain B6 to Datura cells. Octopine had no effect on the binding of virulent A. tumefaciens strain B6 to Datura cells, but 10 millimolar canavanine was inhibitory. Arginine enhanced the adherence of the bacteria at concentrations higher than 0.1 millimolar. Incubation with DNase, RNase, and lipase did not affect the binding, but protease stimulated the adherence of bacteria to Datura cells. Concanavaline A and soybean lectin had little effect whereas lecithin and lysolecithin enhanced binding slightly. Poly-l-lysine markedly stimulated the bacteria-plant cell adherence. Cells from suspension cultures of pea, vetch, and soybean had a 2- to 3-fold higher binding capacity than Datura cells, whereas cells from wheat, corn, rice, and sorghum had a considerably lower affinity for binding with virulent A. tumefaciens strain B6. Bacterial adherence to plant cells was confirmed by autoradiography and electron microscopy. Autoradiographic analysis showed that bacteria were associated with the cell wall, and that often binding of bacteria was localized. Electron micrographs clearly illustrated a tight association of virulent A. tumefaciens strain B6 cells to the Datura cell wall.
利用强致病力的根癌土壤杆菌菌株B6的（32）P标记细胞和悬浮培养的紫花曼陀罗细胞进行了体外结合实验。结合动力学表明，在最初的60分钟内，细菌与紫花曼陀罗细胞的黏附逐渐增加，并在孵育120分钟内达到最高水平。最大结合发生在pH 6.0时。Ca(2+)和Mg(2+)的存在会使结合略有减少，而在0.1至10毫摩尔浓度下，EDTA几乎没有影响。细菌与紫花曼陀罗细胞的结合具有温度依赖性。大肠杆菌、鼠伤寒沙门氏菌、大豆根瘤菌和溶壁微球菌不会与强致病力的根癌土壤杆菌菌株B6竞争与紫花曼陀罗细胞的结合。无毒的根癌土壤杆菌菌株IIBNV6的混合物增强了强致病力的根癌土壤杆菌菌株B6与紫花曼陀罗细胞的黏附。章鱼碱对强致病力的根癌土壤杆菌菌株B6与紫花曼陀罗细胞的结合没有影响，但10毫摩尔的刀豆氨酸具有抑制作用。精氨酸在浓度高于0.1毫摩尔时会增强细菌的黏附。用DNA酶、RNA酶和脂肪酶孵育不会影响结合，但蛋白酶会刺激细菌与紫花曼陀罗细胞的黏附。刀豆球蛋白A和大豆凝集素几乎没有影响，而卵磷脂和溶血卵磷脂会略微增强结合。聚-L-赖氨酸显著刺激细菌与植物细胞的黏附。豌豆、巢菜和大豆悬浮培养物中的细胞与紫花曼陀罗细胞相比，具有高2至3倍的结合能力，而小麦、玉米、水稻和高粱的细胞与强致病力的根癌土壤杆菌菌株B6结合的亲和力则低得多。通过放射自显影和电子显微镜证实了细菌与植物细胞的黏附。放射自显影分析表明细菌与细胞壁相关，并且细菌的结合通常是局部的。电子显微镜照片清楚地显示了强致病力的根癌土壤杆菌菌株B6细胞与紫花曼陀罗细胞壁的紧密结合。
