植物生长抑制剂对万寿菊镉积累和化学形态的影响

通过水培实验研究了细胞分裂抑制剂（青鲜素 MH）和蛋白合成抑制剂（放线菌酮 CHI）对万寿菊镉积累及化学形态的影响。结果表明，在溶液Cd浓度为0.1 mg·L^-1的条件下，投加浓度为2、4 mmol·L^-1青鲜素及3、6 μmol·L^-1放线菌酮显著抑制了万寿菊的相对生长速率及地上部镉含量，另外两种抑制剂也降低了万寿菊地上部可溶性蛋白含量，但对叶绿素a、b及总叶绿素含量并无显著影响，证明细胞分裂及蛋白合成过程直接影响着万寿菊地上部镉积累。通过采用逐步提取法对万寿菊体内镉的化学存在形态分析，表明在单独Cd处理条件下万寿菊体内移动性较差的醋酸提取态及NaCl提取态镉占有较高比例，其中地上部两种结合态镉约占万寿菊地上部总镉量的68%，而施加植物生长抑制剂后万寿菊地上部两种结合态镉含量显著降低，放线菌酮处理下仅为31%，进一步证实镉主要与万寿菊体内蛋白质等物质结合后才能在其体内长久固定，否则不能在其体内发生累积。

Effect of Plant Growth Inhibitors on Accumulation and Chemical Form of Cd in Tagetes erecta L.

A hydroponic experiment was carried out to study the effect of cell division inhibitor（Maleic hydrazide MH ） and protein synthesis inhibitor （Cyeloheximide CHI）on Cd accumulation and chemical forms of Cd in Tagetes erecta L. When 0, 2, 4 mmol·L^-1 MH and 0, 3, 6 μmol·L^-1 CHI were added to 0.1 mg·L^-1 Cd solution for 3 days, the relative growth rate of Tagetes erecta L. was significantly inhibited by the two growth inhibitors, and Cd contents in shoots of Tagetes erecta L. under MH or CHI treatment were 3.1 mg·kg^-1 or 2.2 mg·kg^-1, both of which were obviously decreased as compared with control, the soluble protein contents of Tagetes erecta L. were also decreased under the plant growth inhibitor treatments, but total chlorophyll content, Chlorophyll a, chlorophyll b, and Chlorophyll a/b value in leaves of Tagetes erecta L. were not affected, indicating that Cd accumulation in shoots of Tagetes erecta L. was mainly affected by cell division and protein synthesis. By using sequential extraction, about 68% of the total Cd in leaves of Tagetes erecta L. was found in the extraction of 1 mol· L^-1 NaCl and 2% HAc in 0.1 mg· kg^-1 Cd solution, suggesting that pectates and protein integrated Cd （extracted by 1 mol·L^-1 NaCl） and undissolved Cd phosphate（extracted by 2% HAC ） in Tagetes erecta L. were much higher than other forms of Cd, but the two forms of Cd as mentioned above were significantly decreased when plant growth inhibitors were added to the solution, indicated that the long-term fixation of Cd in Tagetes erecta L, occurred when Cd integrated with protein et al. Contrarily, Cd accumulation in shoots of Tagetes erecta L. would not happen.