Abstract

Understanding metabolic variations of plant essential oils (EOs) in response to different growth conditions is of great importance for bioprospecting and standardizing purposes. In this study, combined gas chromatography-mass spectrometry (GC-MS) based metabolomics and bioassay experiments were carried out to identify chemical differences in W. trilobata EO grown in field and those grown in controlled conditions. Subsequently, the chemical profiles were correlated with their ability to inhibit germination, shoot and root growths of weedy rice and lettuce. Results showed that EO grown in controlled condition was abundant in sesquiterpene hydrocarbons whereas field-grown EO accumulated large amounts of monoterpenes. Principal component analysis (PCA) and orthogonal partial least square discriminant analysis (OPLS-DA) indicated the chemical composition of isolated EOs varied considerably. PLS regression revealed that seed germinations of weedy rice and lettuce were susceptible to W. trilobata EO grown in controlled condition and nonanal may contributed to the phytotoxic activity of the EO. The field-grown EO exhibited strong inhibitory activity against shoot and root growths of weedy rice and lettuce, while α-phellandrene, terpinen-4-ol, trans-pinocarveol and pinocarvone might be responsible for the inhibitory activity. The findings highlight the combination of metabolomics and bioassays to provide a metabolic understanding and bioprospecting potential of W. trilobata EO as bio-herbicides.

摘要

了解植物精油 (EO) 响应不同生长条件的代谢变化对于生物勘探和标准化目的非常重要。在这项研究中，进行了基于气相色谱-质谱联用 (GC-MS) 的代谢组学和生物测定实验，以确定三叶草的化学差异在田间生长的EO和在受控条件下生长的EO。随后，化学成分与它们抑制杂草稻和莴苣的发芽、芽和根生长的能力相关。结果表明，在受控条件下生长的 EO 在倍半萜烃中含量丰富，而田间生长的 EO 则积累了大量的单萜。主成分分析 (PCA) 和正交偏最小二乘判别分析 (OPLS-DA) 表明分离的 EO 的化学成分差异很大。PLS回归显示杂草水稻和莴苣的种子萌发对三叶草易感在受控条件下生长的 EO 和壬醛可能导致 EO 的植物毒性活性。田间种植的 EO 对杂草稻和莴苣的枝条和根系生长有很强的抑制活性，而 α-水芹烯、萜品烯-4-醇、反式香芹酚和松香芹酮可能是抑制活性的原因。这些发现突出了代谢组学和生物测定的结合，以提供对三叶草EO 作为生物除草剂的代谢理解和生物勘探潜力。