A simultaneous extraction method for metabolome and lipidome and its application in cry1Ac and sck-transgenic rice leaf treated with insecticide based on LC-MS analysis

Abiotic stress caused by insecticide treatment is an interesting and challenging topic in plant research. Here a simultaneous extraction method with methyl tert-butyl ether for metabolomics and lipidomics analysis by using rapid resolution liquid chromatography quadrupole time-of-flight mass spectrometry was developed and validated. The extraction efficiency of lipidome and metabolome based on the current developed method showed an obvious improvement compared with literatures. About 300 metabolites were identified in rice leaf. Method validation was performed and analytical properties including the linearity (R-2, 0.991-1.000), repeatability (over 87 % peaks with CV < 20 % accounting for over 92 % of total response) and recovery (74.4-119.6 %) were satisfactory. The method was then applied to investigate time-course changes caused by insecticide treatment in transgenic rice with cry1Ac and sck genes and its wild counterpart. Antioxidants including ferulic acid and sinapic acid were down-regulated at 24 h after insecticide treatment. Signaling metabolites including salicylic acid and nicotinamide adenine dinucleotide were significantly up-regulated at 12-24 h after treatment in transgenic rice. More flavonoids were significantly changed in transgenic plants. Results indicated that gene transformation affected the metabolic response of rice to insecticide stress.