Roles of Metabolites Unveiled by Metabolomics in Brassica rapa, B. napus and B. juncea

Rapeseed is a major source of vegetable oil and contains a wide variety of metabolites. Recent advances, particularly the integration of metabolomics with other omics approaches, have enabled not only comprehensive but also detailed analyses of key metabolites that respond to specific conditions. To date, these recent advances in the metabolomics of Brassica crops have not yet been fully clarified. In this review, we seek to summarize the recent progresses in metabolomics studies of Brassica rapa, B. napus and B. juncea, introduce the key metabolites spanning nucleic acids, amino acids, fatty acids, lipids, organic acids, alkaloids, phenylpropanoids, terpenoids, flavonoids and glucosinolates uncovered by this approach, focusing on those associated with growth and development, and abiotic/biotic stresses, including macronutrient availability, temperature, water stress, salt stress, aluminum and cadmium toxicity, and infection of Sclerotinia sclerotiorum, Leptosphaeria maculans, and Plasmodiophora brassicae. Future perspectives and current challenges in metabolomics integrating with other omics are also discussed, along with its potential for breeding applications, especially in new marker discovery, trait prediction, and even metabolic selection, aimed at developing new rapeseed varieties with stable, high-yielding, and quality traits.