Czuba M, Veliky I
Ecotoxicol Environ Saf. 1984 Dec;8(6):499-506. doi: 10.1016/0147-6513(84)90008-3.
Meristematic cells of carrot (Daucus carota L., Ca68-10) and lettuce (Lactuca sativa L., LE-67) cultured in 71-V medium (with 0.15 microgram/ml 2, 4-D) were given one initial dose (0.0001, 0.001, or 0.01 microgram/ml) of methyl mercury (MeHg) at 0 hr, cultured for 288 hr. and then subcultured for 4 weeks. In another experiment, MeHg was added in four daily doses (0.05, 0.10, 0.50, 1.0, 2.5, or 5.0 micrograms/ml) starting at 72 hr for 120 hr and then subcultured for 168 hr. The resulting 50% growth reduction (Gr50) levels were high--1570 and 540 micrograms Hg/g dry wt for carrot and lettuce, respectively. Methyl mercury was taken up completely by cells but retention decreased at higher MeHg concentrations in the medium. The resistance of undifferentiated cells of both species to MeHg was markedly greater than that observed in multicellular plants. Cells derived from Hg-treated cultures did not recover their growth potential when subcultured in Hg-free medium. The Gr50 levels were lowered during successive subculturing in both carrot (50 micrograms Hg/g) and lettuce (10 micrograms Hg/g), indicating increased sensitivity to residual Hg in cells. This effect depended on the initial Hg concentration and on the number of cell divisions. At low MeHg concentrations, it was observed in cells 12 generations after one initial dose of 0.01 microgram/ml MeHg.
将胡萝卜（胡萝卜属，Ca68 - 10）和生菜（莴苣属，LE - 67）的分生细胞在71 - V培养基（含0.15微克/毫升2,4 - D）中培养，在0小时给予一次甲基汞初始剂量（0.0001、0.001或0.01微克/毫升），培养288小时，然后继代培养4周。在另一项实验中，从72小时开始，以每日四次的剂量添加甲基汞（0.05、0.10、0.50、1.0、2.5或5.0微克/毫升），持续120小时，然后继代培养168小时。最终导致50%生长抑制（Gr50）的水平较高——胡萝卜和生菜分别为1570和540微克汞/克干重。甲基汞被细胞完全吸收，但在培养基中甲基汞浓度较高时，其保留量会降低。这两个物种的未分化细胞对甲基汞的抗性明显大于多细胞植物中的抗性。从经汞处理的培养物中获得的细胞在无汞培养基中继代培养时，其生长潜力无法恢复。在胡萝卜（50微克汞/克）和生菜（10微克汞/克）的连续继代培养过程中，Gr50水平均降低，表明细胞对残留汞的敏感性增加。这种效应取决于初始汞浓度和细胞分裂次数。在低甲基汞浓度下，在初始剂量为0.01微克/毫升甲基汞处理一次后的第12代细胞中观察到了这种效应。
