Gibberellins (GAs) play a pivotal role in modulating plant growth and development. Glucose-conjugated gibberellins (Glc-GAs), a prevalent conjugated form of GAs, regulate intracellular GA levels by the coupling and decoupling of glucose groups. However, the diversity of Glc-GAs identified within individual species remains limited, hinting at a multitude of yet undiscovered gibberellin metabolites. This lacuna poses considerable impediments to research efforts dedicated to comprehensively delineating the GA metabolic pathway. In this study, we developed a structure-oriented screening and identification method for Glc-GAs in plant species by employing LC-MS/MS coupled with chemical derivatization. Through the application of chemical derivatization technique, carboxyl groups on Glc-GAs were labeled which effectively enhanced the sensitivity and selectivity of mass spectrometry detection for these compounds. Concurrently, the integration of mass spectrometry fragmentation and chromatographic retention behavior facilitated the efficient screening and identification of potential Glc-GAs. With this strategy, we screened and identified 12 potential Glc-GAs from six plant species. These findings expand the Glc-GA diversity in plants and contribute to understanding GA metabolic pathways.
Keywords: glucose conjugated gibberellins; isotope labeling; liquid chromatography; mass spectrometry fragmentation; quantitative structure–retention relationship.