ABSTRACT

The use of plant growth regulators to alleviate PAH phytotoxicity is an alternative choice to increase the efficient of PAH phytoremediation. In this study, the capacity of auxin and gibberellin to enhance the growth and PAH removal of ridge gourd (Luffa acutangula (L.) Roxb.) was determined. Indolebutyric acid (IBA) and gibberellic acid (GA₃) at 1 and 10 mg l⁻¹ were applied to ridge gourd by soaking the seeds for 3 h or applied in water to 5 day-olds seedlings that were grown in 100 mg kg⁻¹ phenanthrene- and 100 mg kg⁻¹ pyrene-contaminated soil. The effect of plant growth regulator on PAH removal depended on the application method. IBA-treated plants did not enhance phenanthrene and pyrene biodegradation, while ridge gourd treated with GA₃ by soaking and watering enhanced pyrene biodegradation, when compared with the non-treated plant. GA₃ could increase the pyrene biodegradation, while GA₃ applied with water at a high concentration seemed to retard the plant growth. For plant growth, only the shoot and root fresh weights of ridge gourd in the IBA-soaked treatment were higher than those of the non-treated plant. Watering with 1 mg l⁻¹ GA₃ only enhanced the root fresh weight of the ridge gourd while the GA₃ application decreased the shoot and root length, especially for the 10 mg l⁻¹ water treatment. IBA application did not increase the PAH biodegradation, while IBA applied by seed soaking at a low concentration could increase the plant fresh weight.

摘要

使用植物生长调节剂来减轻 PAH 植物毒性是提高 PAH 植物修复效率的替代选择。在本研究中，测定了生长素和赤霉素促进山葫芦 ( Luffa acutangula (L.) Roxb.) 生长和去除 PAH 的能力。将1 和 10 mg l ^-1的吲哚丁酸 (IBA) 和赤霉酸 (GA ₃ )通过浸泡种子 3 小时施用于脊瓜，或在水中施用于 100 mg kg 生长的 5 日龄幼苗^{- 1}菲和 100 mg kg ^-1芘污染的土壤。植物生长调节剂对 PAH 去除的影响取决于施用方法。与未经处理的植物相比，经IBA处理的植物并没有增强菲和芘的生物降解，而用GA ₃浸泡和浇水处理的葫芦增强了芘的生物降解。GA ₃可以增加芘的生物降解，而GA ₃与高浓度的水一起施用似乎会延缓植物的生长。在植物生长方面，只有经过IBA浸泡处理的葫芦的芽和根鲜重高于未处理的植物。浇水1 mg l ^-1 GA ₃只增加了葫芦的根鲜重，而GA ₃施用减少了枝条和根的长度，特别是对于 10 mg l ^-1水处理。IBA施用不增加PAH生物降解，而低浓度浸种施用IBA可增加植物鲜重。