Wu Qiu-Ling, Wang Wen-Chu, He Shan-Ying
Ying Yong Sheng Tai Xue Bao. 2014 Oct;25(10):2999-3005.
A pot experiment was conducted to study the effects of plant growth regulator GA3 and metal chelate EDTA on enhancing the remediation of Pb contaminated soil, and the detoxification mechanism of Lolium perenne grown on Pb contaminated soil at 250 and 500 mg · kg(-1). The results showed that cell wall deposition and vacuolar compartmentalization played important roles in the detoxification of Pb in L. perenne shoot. The addition of EDTA alone increased Pb concentration in plants and Pb proportions in soluble fraction and organelles fraction, and enhanced the toxicity of Pb to plant, leading to the significant reduction of the plant biomass (P < 0.05). Foliar spray of lower concentration of GA3 (1 μmol · L(-1) or 10 μmol · L(-1)) alone significantly increased Pb accumulation by L. perenne (P < 0.05), but Pb proportions in soluble and organelles fraction were decreased, which alleviated the adverse effects of Pb on plant, thus improving the growth of plants (P < 0.05), with 1 μmol · L(-1) GA3 being the most effective. In contract, the addition of 100 μmol · L(-1) GA3 decreased Pb concentration in L. perenne, but increased the proportions of Pb in soluble fraction and organelles fraction, resulting in the reduction of plant biomass. Lower concen- tration of GA3 might alleviate the adverse effects of Pb and/or EDTA on plant, since the biomass amounts in the different treatments were in order of GA3 alone of lower concentration > GA3 of lower concentration + EDTA > EDTA alone. The combination application of low concentration of GA3 and EDTA showed a synergistic effect on the Pb accumulation in L. perenne (P < 0.05). Especially, Pb concentration in shoot and Pb extraction efficiency reached 1250.6 mg · kg(-1) and 1.1%, respec- tively, under the treatment of EDTA + 1 μmol L(-1) GA3 on the Pb 500 mg · kg(-1) soil. Therefore, the application of 1 μmol · L(-1) GA3 along with EDTA appeared to be a potential approach for phytoremediation of Pb contaminated soil.
进行了一项盆栽试验，以研究植物生长调节剂赤霉素（GA3）和金属螯合剂乙二胺四乙酸（EDTA）对增强铅污染土壤修复效果的影响，以及黑麦草在250和500 mg·kg⁻¹铅污染土壤上生长的解毒机制。结果表明，细胞壁沉积和液泡区室化在黑麦草地上部铅的解毒过程中起重要作用。单独添加EDTA会增加植物中的铅浓度以及可溶部分和细胞器部分中铅的比例，并增强铅对植物的毒性，导致植物生物量显著降低（P<0.05）。单独叶面喷施较低浓度的GA3（1 μmol·L⁻¹或10 μmol·L⁻¹）显著增加了黑麦草对铅的积累（P<0.05），但可溶部分和细胞器部分中铅的比例降低，这减轻了铅对植物的不利影响，从而促进了植物生长（P<0.05），其中1 μmol·L⁻¹ GA3效果最佳。相反，添加100 μmol·L⁻¹ GA3会降低黑麦草中的铅浓度，但增加了可溶部分和细胞器部分中铅的比例，导致植物生物量减少。较低浓度的GA3可能会减轻铅和/或EDTA对植物的不利影响，因为不同处理下的生物量大小顺序为：单独较低浓度的GA3>较低浓度的GA3+EDTA>单独的EDTA。低浓度GA3和EDTA的联合应用对黑麦草中铅的积累具有协同作用（P<0.05）。特别是，在铅含量为500 mg·kg⁻¹的土壤上，采用EDTA + 1 μmol L⁻¹ GA3处理时，地上部铅浓度和铅提取效率分别达到1250.6 mg·kg⁻¹和1.1%。因此，1 μmol·L⁻¹ GA3与EDTA联合应用似乎是一种修复铅污染土壤的潜在方法。
