Glucosinolates in brassicaceae: An updated overview from biosynthesis to metabolic engineering

Glucosinolates (GSLs) are sulfur- and nitrogen-containing secondary metabolites predominantly found in Brassicaceae crops such as broccoli, cabbage, cauliflower, canola, and radish. The bioactive products of GSLs play crucial roles not only in plant defense but also in human health. However, natural GSL profiles vary widely among Brassica species, and several factors, including the presence of active myrosinase enzyme, storage conditions, food matrix composition, gut microbial composition, and inter-individual variability, influence bioavailability and physiological activity of GSLs. Moreover, certain GSLs or their derivatives exert adverse effects in humans, highlighting the need for precise regulation of their composition through targeted breeding and metabolic engineering. Over the past decade, considerable research has focused on metabolic and genetic engineering strategies to modify GSL biosynthesis in Brassica crops, aiming to enhance their agronomic traits and health-promoting potential while minimizing anti-nutritional properties. Despite these achievements, comprehensive integration of GSL structure, biosynthesis, human bioavailability, and metabolic engineering in Brassica remains limited. In this context, the present review provides an updated overview of GSL biosynthetic pathways, their multifaceted roles in plant defense and human health, and recent advances in genetic and metabolic engineering approaches aimed at optimizing GSL content and composition. Finally, the review highlights current research gaps and outlines future directions to fully harness GSLs for crop improvement and public health applications, serving as a valuable resource for researchers working in this evolving field.