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.

Background: Small RNA, defined as RNA molecules of less than 200 nucleotides in length, play pivotal regulatory roles in plant growth, development, and environmental stress responses. However, research on modifications in plant small RNA remains limited. Methods: In this study, we developed a liquid chromatography–tandem mass spectrometry (LC-MS/MS) method for the simultaneous detection of 41 RNA modifications, facilitating the systematic qualification and quantification of modifications in plant small RNA. Results: We identified a total of nine modifications, among which N⁶,N⁶-dimethyladenosine (m^6,6A) is a newly identified modification in plant small RNA. Furthermore, we conducted a quantitative analysis of these modifications in Arabidopsis thaliana during the germination process and observed significant dynamic changes in their abundance from 1 to 5 days post-germination. Notably, the trends in the contents of these modifications exhibited a strong correlation with the reported gene expression levels of the relevant modifying enzymes and demodifying enzymes, suggesting that these modifications may play essential roles during seed germination and are tightly regulated by the genes of the corresponding enzymes. Conclusions: The discovery of these modifications in plant small RNA, coupled with the dynamic changes in their levels during germination, holds great promise for a further understanding of the physiological functions of small RNA modifications and their associated regulatory mechanisms in plant seed germination.