EDTA对黄菖蒲和马蔺Cu吸收积累的影响

Effects of EDTA on Cu absorption and accumulation of Iris pseudacorus and Iris lactea var. chinesis

采用水培的方法研究了乙二胺四乙酸(EDTA)对2种鸢尾属Cu富集型植物(黄菖蒲、马蔺)对Cu的吸收和积累的影响。结果表明:在0.55 mmol·L-1(35 mg·L-1)Cu胁迫下加入EDTA(0.28,0.55 mmol·L-1)能够显著促进植物体对Cu的吸收,并促进Cu向地上部的转移,同时黄菖蒲、马蔺的地上和地下生物量也显著增加,缓解了Cu对2种植物生长的抑制作用。黄菖蒲和马蔺地上部脯氨酸(Pro)含量升高、MDA含量降低,也进一步表明一定浓度的EDTA能够减轻Cu对植物的毒害。但是,当溶液中EDTA浓度大于0.55 mmol·L-1时,其效果不明显,表现为抑制Cu在根部的吸附,进而降低Cu向地上部的转移,但与低浓度EDTA处理相比,高浓度EDTA(1.10 mmol·L-1)下的两种植物生物量显著下降,表明高浓度EDTA会产生毒害作用。

The effects of EDTA on Cu absorption, accumulation and physiological and biochemical parameters in Iris pseudacorus L. and Iris lactea vat. chinesis（ Fiseh. ）Roide were studied by hydroponic method. The results showed that addition of EDTA （0. 28 and 0. 55 mmol＇L-1 ） relieved the toxicity of Cu （0. 55 mmol.L-1 ） as indicated by the increased biomass of the two plant species compared with Cu treatment alone. However, under Cu stress, addition of 1.10 mmol L-l EDTA showed negative effect that the biomass of two plants decreased compared with 0. 28 and 0. 55 mmol. L- 1 EDTA treatments. Addition of EDTA （0. 28-0. 55 mmol L-1 ） promoted the transference of Cu from root to shoot in two plants. The highest total Cu accumulation of shoots of the two plants was observed in 0. 55 mmol. L - 1 EDTA treatment. The mitigating effect of EDTA on Cu stress was also showed by the increased contents of proline and decreased MDA contents in the leaves of Iris pseudacorus L. and Iris lactea var. chinesis（ Fisch. ） Roide. There was no significant effect when the concentration of EDTA was higher than 0. 55 mmol L-1 , indicating that the accu- mulation of Cu in roots decreased, as well as the shoots. But higher concentration of EDTA （ 1.10 mmol. L-1 ） could lead to the decrease in hiomass of two plant species, which showed that higher EDTA concentration could resuh in toxicity.