ABSTRACT As the main active ingredient of the traditional Chinese medicine Glycyrrhiza uralensis Fisch, liquiritin has multiple biological activities, including anti-inflammatory, antihepatotoxicity, immune regulation, anti-virus and anti-cancer. In addition, liquiritin has been recognized as an allelochemical that displays markedly inhibitory effects on the growth of target plants, G. uralensis and lettuce. However, its phytotoxic mechanism remains unknown. In the present study, the mode of action of liquiritin against root growth of lettuce seedling was researched. After treatments with liquiritin, the cell division in root tips of lettuce seedlings was partly arrested, and the cell viability and root vitality were obviously lost. At the same time, overproduction of reactive oxygen species (ROS), malondialdehyde (MDA) and proline (Pro) in lettuce seedlings were induced by liquiritin. The results indicated that the phytotoxic effects of liquiritin was probably dependent on the induction of ROS overproduction, resulting in membrane lipids peroxidation following with cell death and mitosis process disorder.

中文翻译：

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化感化学甘草苷对生菜幼苗根系生长的药害机制


摘要 甘草苷作为中药甘草的主要活性成分，具有抗炎、抗肝毒性、免疫调节、抗病毒、抗癌等多种生物活性。此外，甘草苷已被认为是一种化感化学物质，对目标植物G. uralensis和生菜的生长具有显着的抑制作用。然而，其植物毒性机制仍不清楚。本研究主要研究了甘草苷对生菜幼苗根系生长的作用方式。甘草苷处理后，生菜幼苗根尖细胞分裂部分受到抑制，细胞活力和根系活力明显丧失。同时，甘草苷还诱导生菜幼苗中活性氧（ROS）、丙二醛（MDA）和脯氨酸（Pro）的过量产生。结果表明，甘草苷的药害作用可能依赖于诱导ROS过量产生，导致膜脂过氧化，进而导致细胞死亡和有丝分裂过程紊乱。