Analysis of global metabolome by gas chromatography-mass spectrometry of Pyropia haitanensis stimulated with 1-octen-3-ol

Abstract

1-Octen-3-ol is a major volatile metabolite produced by red seaweed Pyropia haitanensis under stresses. Using a metabolic profiling approach, we identified metabolites in P. haitanensis affected by 1-octen-3-ol treatment. The thalli were exposed to 1-octen-3-ol for 0.5 and 1 h. Using a non-targeted GC-MS analysis, 246 peaks in control and 1-octen-3-ol-treated P. haitanensis were detected. Among them, 72 metabolites were identified. Further statistical analysis revealed that these 72 metabolites covered different types of primary metabolism and secondary metabolism pathways, including organic acids, carbohydrates, amino acids, glycols, and fatty acids. PCA and PLS-DA analyses revealed that the metabolic composition differed between the control and 1-octen-3-ol-treated samples, and the main metabolites contributing to the dispersion were fatty acid, citric acid, some sugars, and amino acids. However, the metabolic compositions between two 1-octen-3-ol-treated samples (0.5 and 1 h) were similar. Pyropia haitanensis treated with 1-octen-3-ol showed reduced levels of certain free fatty acids and an increased level of monoacylglycerol. In addition, the synthesis of many amino acids and photosynthetic product galactosylglycerol was increased, along with some essential metabolites in the primary metabolic pathways, such as glycerol-3-phosphate, organic acids, and others. These results indicated that P. haitanensis recognized 1-octen-3-ol, which accelerated its primary metabolism to promote cell growth under stresses. These findings provided useful information on how algae respond to stress-induced signal.