Widely targeted metabolomics reveals metabolic patterns during tetraspore formation in the edible seaweed Gracilariopsis lemaneiformis

A sustainable food supply is crucial for addressing the food crisis resulting from the increasing global population. Seaweeds are promising food candidates because of their nutritional value and favorable growing conditions, as they do not occupy arable land or require fresh water. Gracilariopsis lemaneiformis (Rhodophyta), known for its ability to produce agar, is attracting increasing attention in the food industry. To develop new G. lemaneiformis germplasms, the four stages tetrasporophyte development and related molecular mechanisms were previously studied, but the metabolite changes that occur during the reproductive process remain unknown. In this study, we employed comprehensive metabolomics technology to examine changes in metabolites during the reproductive process of G. lemaneiformis , and a total of 817 metabolites were found, including 355 differentially accumulated metabolites (DAMs). The results revealed that G. lemaneiformis fulfills its energy requirements during reproduction by increasing glycolysis and TCA cycle flux, while it meets its material requirements by activating amino acid and nucleotide metabolism. Additionally, a significant accumulation of biogenic amines produced by the shikimate pathway may promote the formation of tetraspores, and a combination of flavonoids and phenolic acids effectively preserved the balance of the antioxidant system during the reproductive process of G. lemaneiformis . In this research, we analyzed changes in metabolites during the transition from the nutritional stage to the reproductive stage of G. lemaneiformis , revealing the potential relationship between tetraspore formation and metabolites and providing a theoretical basis for the cultivation of new germplasms of G. lemaneiformis .